Mechanical extension structure, seat unit, sofa, and control method for sofa

Abstract

The present application relates to a mechanical extension structure, a seat unit, a sofa, and a control method for the sofa, used for solving the problem that a sofa catches the clothes of a user. The mechanical extension structure comprises: a base; a support frame, located above the base; two swing mechanisms, wherein the base and the support frame are movably connected by means of the swing mechanisms; a linkage rod, wherein each swing mechanism is fixedly connected to an end portion of the linkage rod; two backrest assemblies, provided behind the base and the support frame; two leg assemblies, provided in front of the support frame; and a first driving device, used for driving the leg assemblies to move. When the mechanical extension structure is located at a TV-viewing position, the included angle between the center line of a front backrest bracket and a mounting surface is greater than 90°; when the mechanical extension structure is changed from the TV-viewing position to a reclining position, a backrest plate moves forward, and the front backrest bracket rotates relative to the support frame; when the mechanical extension structure is located at the reclining position, the included angle between the center line of the front backrest bracket and the mounting surface is less than 90°.

Description

Mechanical extension structure, seat unit, sofa and sofa control method Technical Field

[0001] This application relates to a mechanical extension structure, a seat unit, a sofa, and a method for controlling the sofa. Background Technology

[0002] The application number is 2020225219786, and the patent name is a utility model patent for a zero-wall-leaning functional sofa mechanical extension device. It discloses a backrest assembly, a triangular connector, a backrest support, and a side panel. The backrest support and the side panel are rotatably connected to the triangular connector. The triangular connector is fixedly connected to the backrest structure, and the side panel is fixedly connected to the seat cushion structure.

[0003] The mechanical extension device has a sitting position and a reclining position. Because the triangular connector is rotatably connected to the side plate, the distance between the backrest structure and the seat cushion structure continuously decreases during the process of changing from the reclining position to the sitting position, eventually clamping the user's clothes.

[0004] In addition, in related technologies, the seat unit includes a leg assembly, a base, a seat base, and at least one drive device, with the leg assembly movably disposed on the base; the seat unit preferably has one or two drive devices, and the drive device is usually an electric motor.

[0005] In this design, when the seat unit includes a motor, rollers are installed on the base. One end of the motor is located on the leg assembly, and the other end is located on the base. After the motor drives the leg assembly to move, the leg assembly drives the base to move, so that the base rolls along the base via the rollers. The disadvantages of this design are: 1. The rollers are prone to generating noise during the rolling process; 2. If foreign matter adheres to the roller surface, the rollers are prone to vibration during the rolling process; 3. If the roller surface has cracks or damage, the rollers are prone to eccentric rolling during the rolling process.

[0006] When the seat unit includes two motors, one end of the first motor is located on the leg assembly, and the other end is located on the base. The first motor drives the leg assembly to move relative to the base. One end of the second motor is located on the base, and the other end is located on the seat base. The second motor drives the base to slide relative to the seat base. The disadvantages of this design are: the manufacturing cost of two motors is high, and each motor requires a separate on / off switch for control.

[0007] Therefore, the seat units in related technologies cannot balance reliability and manufacturing cost. Summary of the Invention

[0008] The problem to be solved by this application is to provide a mechanical extension structure, a seat unit, a sofa, and a method for controlling the sofa.

[0009] To address the above problems, this application provides the following technical solution:

[0010] Mechanical extension structures include:

[0011] Base;

[0012] The base is located above the pedestal;

[0013] Two sets of swing mechanisms, with the base and the pedestal movably connected via the swing mechanisms;

[0014] Linkage rod, each set of swing mechanisms is fixedly connected to the end of the linkage rod;

[0015] Two backrest components are located at the base and behind the pedestal;

[0016] Two sets of leg components are located at the front of the base;

[0017] The first drive mechanism is used to drive the leg components to move;

[0018] The mechanical extension structure has a sitting position, a TV position, and a reclining position. During the transition from the sitting position to the reclining position, the first drive mechanism drives the base forward through the leg assembly, so that the leg assembly extends in front of the base and the backrest assembly tilts backward relative to the base. During the transition from the reclining position to the sitting position, the first drive mechanism drives the base backward through the leg assembly, so that the leg assembly retracts under the base and the backrest assembly returns to its original position relative to the base.

[0019] The base is provided with a mounting surface for mounting the seat cushion structure. Each backrest assembly includes a backrest panel and a front backrest bracket. The backrest panel and the base are rotatably connected to the front backrest bracket.

[0020] During the transition from a seated position to a TV position, the backrest and the front backrest support move forward, while the front backrest support remains stationary relative to the base. When the mechanical extension structure is in the TV position, the angle between the centerline of the front backrest support and the mounting surface is greater than 90°. During the transition from a TV position to a reclining position, the backrest moves forward and the front backrest support rotates relative to the base. When the mechanical extension structure is in the reclining position, the angle between the centerline of the front backrest support and the mounting surface is less than 90°.

[0021] Preferably, the backrest panel has an installation position for mounting the backrest structure and a transition position for rotatably connecting with the front support of the backrest. The angle between the line connecting the midpoint of the installation position and the midpoint of the transition position and the installation surface is α. The α of the mechanical extension structure in the TV position is greater than the α of the mechanical extension structure in the reclining position.

[0022] Preferably, the base is provided with a first limiting rod. When the mechanical extension structure is in the sitting position, TV position, and reclining position, the first limiting rod abuts against the front support of the backrest. During the process of the mechanical extension structure changing from the sitting position to the TV position, the first limiting rod abuts against the front support of the backrest. During the process of the mechanical extension structure changing from the TV position to the reclining position, the first limiting rod does not abut against the front support of the backrest.

[0023] Preferably, the length of the front backrest support above the rotatable connection between the front backrest support and the base is greater than the length of the front backrest support below the rotatable connection between the front backrest support and the base; when the mechanical extension structure is in the TV position, the transition position is located behind the first limiting rod, the first limiting rod abuts against the front backrest support and prevents the front backrest support from moving downward; when the mechanical extension structure is in the reclining position, the transition position is located in front of the first limiting rod, the first limiting rod abuts against the front backrest support and prevents the front backrest support from moving upward.

[0024] Preferably, each set of swing mechanisms includes:

[0025] The front support plate is rotatably connected to the base;

[0026] The rear support plate is rotatably connected to the base;

[0027] The inner swing assembly, base, backrest assembly, leg assembly, front support plate and rear support plate are movably connected to the inner swing assembly respectively;

[0028] The external swing assembly is movably connected to the leg assembly, and the linkage rod is fixedly connected to the external swing assembly;

[0029] The backrest assembly also includes a backrest support bracket rotatably connected to the backrest panel, and the inner swing assembly includes a rear swing plate, with the base, rear support plate, and backrest support bracket rotatably connected to the rear swing plate respectively.

[0030] Preferably, the backrest assembly further includes a backrest connecting bracket, one end of which is rotatably connected to the front backrest bracket, and the other end of which is rotatably connected to the rear swing plate; wherein, during the process of the mechanical extension structure changing from a sitting position to a TV position, the front backrest bracket remains in a fixed position relative to the backrest connecting bracket; during the process of the mechanical extension structure changing from a TV position to a reclining position, the front backrest bracket rotates relative to the backrest connecting bracket.

[0031] Preferably, a second limiting rod is provided on the backrest panel. When the mechanical extension structure is in the sitting position and the TV position, the second limiting rod abuts against the backrest support. During the process of the mechanical extension structure changing from the sitting position to the TV position, the second limiting rod abuts against the backrest support.

[0032] Preferably, the front support of the backrest is provided with a third limiting rod, so that when the mechanical extension structure is in the TV position, the backrest does not abut against the third limiting rod; the base is provided with a first limiting rod, so that when the mechanical extension structure is in the reclining position, the backrest does not abut against the second limiting rod, the backrest abuts against the third limiting rod, and the front support of the backrest abuts against the first limiting rod; wherein, during the process of the mechanical extension structure changing from the TV position to the reclining position, the back support of the backrest does not abut against the third limiting rod, the front support of the backrest does not abut against the first limiting rod, and the back support of the backrest does not abut against the second limiting rod.

[0033] Preferably, the rotatable connection between the rear support plate and the rear swing plate is located above the rotatable connection between the backrest connecting bracket and the rear swing plate, and the rotatable connection between the base and the rear swing plate is located below the rotatable connection between the backrest connecting bracket and the rear swing plate.

[0034] The rear swing plate is equipped with a fourth limiting rod. When the mechanical extension structure is in the sitting position, when the mechanical extension structure is in the TV position, and during the process of the mechanical extension structure changing from the sitting position to the TV position, the fourth limiting rod abuts against the base. When the mechanical extension structure is in the lying position, and during the process of the mechanical extension structure changing from the TV position to the lying position, the fourth limiting rod does not abut against the base.

[0035] Preferably, the base is provided with a fifth limiting rod, and the inner swing assembly further includes:

[0036] The front swing plate has one end rotatably connected to the front support plate and the other end rotatably connected to the base plate.

[0037] A swing connecting plate, one end of which is rotatably connected to the front swing plate, and the other end of which is rotatably connected to the rear swing plate;

[0038] The intermediate swing plate is rotatably connected to the base plate.

[0039] The upper swing plate has one end rotatably connected to the front support plate and the other end rotatably connected to the middle swing plate.

[0040] The lower swing plate has one end rotatably connected to the leg assembly and the other end rotatably connected to the middle swing plate.

[0041] Specifically, when the mechanical extension structure is in the seated position, when the mechanical extension structure is in the TV position, and during the process of the mechanical extension structure changing from the seated position to the TV position, the fifth limiting rod abuts against the front swing plate, and the fifth limiting rod is located above the front swing plate.

[0042] Preferably, the rear swing plate is provided with a fourth limiting rod. When the mechanical extension structure is in the sitting position, when the mechanical extension structure is in the TV position, and during the process of the mechanical extension structure changing from the sitting position to the TV position, the fourth limiting rod supports the base and the front swing plate supports the fifth limiting rod. When the mechanical extension structure is in the lying position, and during the process of the mechanical extension structure changing from the TV position to the lying position, the fourth limiting rod does not abut against the base.

[0043] When the fourth limiting rod supports the base and the front swing plate supports the fifth limiting rod, the rear swing plate prevents the base from sinking relative to the base through the fourth limiting rod, and the front swing plate prevents the base from sinking relative to the base through the fifth limiting rod.

[0044] Preferably, the front swing plate is located in front of the rear swing plate; wherein the mounting surface is located below the fifth limiting rod, and / or the mounting surface is located above the fourth limiting rod.

[0045] Preferably, the mounting surface is located on the outside of the base, and / or the fifth limiting rod and the front swing plate are located on the inside of the base.

[0046] Preferably, a sixth limiting rod is provided on the front swing plate, and a ninth limiting rod is provided on the middle swing plate. When the mechanical extension structure is in the seated position, the upper end face of the front part of the swing link supports the sixth limiting rod, and the upper end face of the rear part of the swing link abuts against the ninth limiting rod. When the mechanical extension structure is in the TV position, and during the process of the mechanical extension structure changing from the seated position to the TV position, the upper end face of the front part of the swing link supports the sixth limiting rod, and the ninth limiting rod separates from the swing link. Among them, when the mechanical extension structure is in the seated position, the fifth limiting rod is located between the front support plate and the sixth limiting rod.

[0047] Preferably, the mechanical extension structure further includes a first support plate and a second support plate, one end of the second support plate being rotatably connected to the base, the other end of the second support plate being rotatably connected to the first support plate, one end of the first support plate being rotatably connected to the front support plate, and the other end of the first support plate being provided with a roller; or, the mechanical extension structure further includes a first support plate and a second support plate, one end of the second support plate being rotatably connected to the base, the other end of the second support plate being provided with a roller, one end of the first support plate being rotatably connected to the front support plate, and the other end of the first support plate being rotatably connected to the second support plate; when the mechanical extension structure is in a lying position, and during the process of the mechanical extension structure changing from a TV position to a lying position, the sixth limiting rod separates from the swing connecting plate, and the lower end surface of the roller is not higher than the lower end surface of the base.

[0048] Preferably, the front support of the backrest is located behind the middle swing plate, and a third limiting rod is provided on the front support of the backrest. An upper groove with an upward opening is provided on the base. When the mechanical extension structure is in the lying position, the backrest plate abuts against the third limiting rod, and the third limiting rod abuts against the groove wall of the upper groove.

[0049] Preferably, the backrest assembly further includes a backrest rear support, a first backrest support, a second backrest support, and a third backrest support. One end of the backrest rear support is rotatably connected to the backrest panel, and the other end of the backrest rear support is rotatably connected to the base. One end of the first backrest support is rotatably connected to the front backrest support, and the other end of the first backrest support is rotatably connected to one end of the second backrest support. The second backrest support is rotatably connected to the base, and the other end of the second backrest support is rotatably connected to one end of the third backrest support. The other end of the third backrest support is rotatably connected to the base.

[0050] The backrest front support is equipped with a third limiting rod. When the mechanical extension structure is in the sitting position or in the TV position, the second backrest support abuts against the third limiting rod. When the mechanical extension structure is in the reclining position or during the process of changing the mechanical extension structure from the TV position to the reclining position, the second backrest support does not abut against the third limiting rod.

[0051] Preferably, a seventh limiting rod is provided on the backrest panel. When the mechanical extension structure is in the sitting position, when the mechanical extension structure is in the TV position, and during the process of the mechanical extension structure changing from the sitting position to the reclining position, the seventh limiting rod does not abut against the front support of the backrest; when the mechanical extension structure is in the reclining position, the seventh limiting rod abuts against the front support of the backrest; and / or, an eighth limiting rod is provided on the base. When the mechanical extension structure is in the sitting position, when the mechanical extension structure is in the TV position, and during the process of the mechanical extension structure changing from the sitting position to the reclining position, the eighth limiting rod does not abut against the front support of the backrest; when the mechanical extension structure is in the reclining position, the eighth limiting rod abuts against the front support of the backrest.

[0052] The seat unit includes the mechanical extension structure described in any of the above technical solutions. The first drive mechanism includes a motor and a telescopic assembly. The motor has a motor shaft, which is connected to the telescopic assembly through a transmission mechanism. The motor is located on the base. The telescopic assembly is also movably connected to one of the linkage rod and the leg assembly.

[0053] Preferably, the motor is movably mounted on the base, and the center line of the motor shaft coincides with the center line of the telescopic assembly. The telescopic assembly includes an outer rod and an inner rod located inside the outer rod. The outer rod and the inner rod are threaded together, and the motor shaft and the inner rod are connected through a transmission mechanism. During the operation of the motor, the rotational speed of the motor shaft is different from the rotational speed of the inner rod.

[0054] Preferably, the leg assembly includes a transmission rod, an outer rod rotatably connected to the transmission rod, and the transmission rod rotatably connected to the base; and / or, the motor includes a body with a protective cover fitted over the outer rod, wherein when the mechanical extension structure is in a seated position, the transmission rod is exposed outside the protective cover; and when the mechanical extension structure is in a reclining position, the inner rod is not exposed outside the protective cover.

[0055] The seat unit includes the mechanical extension structure described in any of the above technical solutions. The first drive mechanism includes a motor and a telescopic assembly. The motor has a motor shaft, which is connected to the telescopic assembly through a transmission mechanism. The motor is located on the base. The telescopic assembly is also movably connected to one of the linkage rod and the leg assembly.

[0056] Preferably, the motor is movably mounted on the base, and the center line of the motor shaft coincides with the center line of the telescopic assembly. The telescopic assembly includes an outer rod and an inner rod located inside the outer rod. The outer rod and the inner rod are threaded together, and the motor shaft and the inner rod are connected through a transmission mechanism. During the operation of the motor, the rotational speed of the motor shaft is different from the rotational speed of the inner rod.

[0057] Preferably, the leg assembly includes a transmission rod, an outer rod rotatably connected to the transmission rod, and the transmission rod rotatably connected to the base; and / or, the motor includes a body with a protective cover fitted over the outer rod, wherein when the mechanical extension structure is in a seated position, the transmission rod is exposed outside the protective cover; and when the mechanical extension structure is in a reclining position, the inner rod is not exposed outside the protective cover.

[0058] The seat unit includes the mechanical extension structure described in any of the above technical solutions. The first drive mechanism includes a motor and a telescopic component. The motor has a motor shaft, and the motor shaft is connected to the telescopic component through a transmission mechanism. One of the motor and the telescopic component is movably disposed on the leg assembly, and the other of the two is movably connected to the swing mechanism.

[0059] Preferably, the centerline of the motor shaft coincides with the centerline of the telescopic assembly. The telescopic assembly includes an outer rod and an inner rod located inside the outer rod. The outer rod and the inner rod are threaded together, and the motor shaft and the inner rod are connected through a transmission mechanism. During motor operation, the rotational speed of the motor shaft is different from the rotational speed of the inner rod.

[0060] Preferably, the leg assembly includes a transmission rod, a motor is rotatably connected to the transmission rod, and an outer rod is rotatably connected to the swing mechanism; and / or, the motor includes a body with a protective cover, the protective cover being fitted onto the outer rod, the transmission rod being exposed outside the protective cover when the mechanical extension structure is in a seated position; and the inner rod not being exposed outside the protective cover when the mechanical extension structure is in a lying position.

[0061] The sofa includes a backrest structure and a seat cushion structure, including the seating unit described in any of the above technical solutions; wherein the backrest structure is detachably disposed on the backrest assembly, and / or the seat cushion structure is hung on the base.

[0062] Preferably, the backrest structure is provided with a buckle plate, and the backrest plate is provided with a mounting hole. The mounting hole is a stepped hole. The buckle plate is inserted into the mounting hole and abuts against the stepped surface of the stepped hole to fix the backrest structure to the backrest plate. The distance between the stepped surface and the large-diameter end opening of the stepped hole is <2mm.

[0063] Preferably, the sofa includes a snap-on plate, a first slide rail on the backrest structure, the snap-on plate can slide along the first slide rail, and a mounting hole is provided on the backrest plate. The snap-on plate is inserted into the mounting hole to fix the backrest structure to the backrest plate. An elastic element is provided between the snap-on plate and the backrest structure. The snap-on plate moves along the first slide rail to change the shape of the elastic element.

[0064] Preferably, the elastic element is a compression spring. During the process of the mechanical extension structure changing from a sitting position to a lying position, the backrest structure moves backward relative to the seat cushion structure, so that the buckle plate moves relative to the first slide rail and squeezes the compression spring; during the process of the mechanical extension structure changing from a lying position to a sitting position, the backrest structure moves forward relative to the seat cushion structure, and the compression spring pushes the buckle plate to move along the first slide rail.

[0065] Preferably, the mechanical extension structure further includes a second slide rail and a sliding member. The sliding member is provided with a leg structure. The second slide rail is disposed on the base. The sliding member is slidably disposed on the second slide rail. The sliding member slides relative to the second slide rail so that the leg structure moves closer to or further away from the seat structure.

[0066] Preferably, the second slide rail is fixedly connected to the base. When the mechanical extension structure is in a sitting position, the leg structure is located below the seat cushion structure. During the process of the mechanical extension structure changing from a sitting position to a lying position, the leg structure moves outward relative to the seat cushion structure.

[0067] Alternatively, the second slide rail is movably connected to the base, so that when the mechanical extension structure is in a sitting position, the leg structure is located below the seat cushion structure; during the process of the mechanical extension structure changing from a sitting position to a lying position, the leg structure rotates upward relative to the seat cushion structure.

[0068] Preferably, when the second slide rail is fixedly connected to the base, the second slide rail is located below the leg structure, and the leg structure and the seat cushion structure are connected by sofa fabric; when the second slide rail is movably connected to the base, the second slide rail is located on the side of the leg structure, and the leg structure and the seat cushion structure are integrated.

[0069] Preferably, the seat cushion structure includes a hook with an anti-slip part, and a base with a hanging rod for hanging the hook. The hanging rod has at least two mating parts, and when the hook is hung on the hanging rod, the anti-slip part abuts against one of the mating parts.

[0070] The sofa control method includes the sofa described in any of the above technical solutions, and the sofa further includes:

[0071] The headrest structure is movably mounted above the backrest structure;

[0072] The second drive mechanism has one end rotatably connected to the backrest structure and the other end rotatably connected to the headrest structure.

[0073] A control switch is electrically connected to the first drive mechanism and the second drive mechanism;

[0074] A signal acquisition device is used to collect electrical signals;

[0075] The controller, signal acquisition unit, and control switch are all electrically connected to the controller.

[0076] Sofa control methods include:

[0077] The signal acquisition device transmits the acquired electrical signals to the controller. Based on the electrical signals, the controller controls the first drive mechanism and the second drive mechanism to work through the control switch, so that the mechanical extension structure can change between a sitting position and a lying position, and the second drive mechanism can adjust the position of the headrest structure relative to the backrest structure.

[0078] Preferably, the sofa includes two seat units, and the signal acquisition unit includes a first voice acquisition module and a second voice acquisition module. The first voice acquisition module is used to collect a first electrical signal from one of the seat units, and the second voice acquisition module is used to collect a second electrical signal from the other seat unit.

[0079] Preferably, the sofa includes two seat units, and the signal acquisition unit includes a first voice acquisition module and a second voice acquisition module. The first voice acquisition module is adjacent to one of the seat units, and the second voice acquisition module is adjacent to the other seat unit. A signal comparison module is provided between the first voice acquisition module, the second voice acquisition module and the controller. The signal comparison module is used to determine the magnitude of the voltage or current value of different electrical signals.

[0080] The first electrical signal acquired by the first voice acquisition module and the second electrical signal acquired by the second voice acquisition module are respectively transmitted to the signal comparison module. The signal comparison module transmits one of the first electrical signal and the second electrical signal to the controller. The controller controls the first drive mechanism on a seat unit to work through a control switch, so that the first drive mechanism on the seat unit adjusts the position of the base relative to the base.

[0081] The sofa control method includes the sofa described in any of the above technical solutions, and the sofa further includes:

[0082] Gravity sensor, used to collect real-time gravity signals, is located in the seat cushion structure and / or backrest structure;

[0083] The control switch is electrically connected to the first drive mechanism;

[0084] A signal acquisition device is used to acquire real-time voice signals.

[0085] The controller, gravity sensor, signal acquisition unit, and control switch are electrically connected to the controller.

[0086] Sofa control methods include:

[0087] When the gravity sensor acquires a real-time gravity signal, the signal acquisition device is activated to collect real-time voice signals.

[0088] The signal acquisition unit identifies the real-time voice signal to determine whether the real-time voice signal includes a wake word;

[0089] After determining that the real-time voice signal collected by the signal collector includes a wake-up word, the signal collector collects a real-time voice signal containing control commands and transmits the real-time voice signal containing control commands to the controller. Based on the real-time voice signal, the controller controls the first drive mechanism to work through a control switch so that the mechanical extension structure can change between a sitting position and a lying position.

[0090] Preferably, the sofa also includes an ambient light, which is electrically connected to a control switch. The gravity sensor transmits the real-time gravity signal it collects to the controller. After receiving the real-time gravity signal, the controller turns on the ambient light through the control switch.

[0091] Preferably, the sofa also includes an ambient light and a photosensitive sensor for collecting real-time light signals. The ambient light is electrically connected to a control switch, and the photosensitive sensor is electrically connected to a controller.

[0092] The controller presets a specified light signal and a specified gravity signal. The gravity sensor collects the real-time gravity signal and transmits it to the controller. The photosensitive sensor collects the real-time light signal and transmits it to the controller. After comparing the specified gravity signal with the real-time gravity signal and the specified light signal with the real-time light signal, the controller turns the ambient light on or off by controlling the switch.

[0093] Preferably, the gravity sensor transmits the real-time gravity signal it collects to the controller. After the controller determines that the specified gravity signal value is greater than the real-time gravity signal value, the controller receives the real-time light signal collected by the photosensitive sensor.

[0094] After the controller determines that the specified light signal value is greater than the real-time light signal value, the controller turns on the ambient light by controlling the switch.

[0095] The sofa control method includes the sofa described in any of the above technical solutions, and the sofa further includes:

[0096] Ambient lighting is installed on the seat cushion structure and / or backrest structure;

[0097] Gravity sensor, used to collect real-time gravity signals, is located in the seat cushion structure and / or backrest structure;

[0098] A photosensitive sensor is used to collect real-time light signals;

[0099] The control switch is electrically connected to the first drive mechanism and the ambient light.

[0100] The controller, gravity sensor, photosensor, and control switch are electrically connected to the controller.

[0101] Sofa control methods include:

[0102] The controller presets a specified light signal and a specified gravity signal. The gravity sensor collects the real-time gravity signal and transmits it to the controller. The photosensitive sensor collects the real-time light signal and transmits it to the controller. After comparing the specified gravity signal with the real-time gravity signal and the specified light signal with the real-time light signal, the controller turns the ambient light on or off by controlling the switch.

[0103] The sofa control method includes the sofa described in any of the above technical solutions, and the sofa further includes:

[0104] Gravity sensor, used to collect real-time gravity signals, is located in the seat cushion structure and / or backrest structure;

[0105] A first position sensor is electrically connected to a first drive mechanism, and the first position sensor is used to collect the first real-time position signal of the first drive mechanism.

[0106] The control switch is electrically connected to the first drive mechanism;

[0107] The controller, the first position sensor, the gravity sensor, and the control switch are electrically connected to the controller respectively;

[0108] Sofa control methods include:

[0109] The controller presets a first designated position signal. When the gravity sensor fails to collect a real-time gravity signal, the controller collects the first real-time position signal from the first position sensor and determines whether the mechanical extension structure is in a seated position by comparing the first designated position signal with the first real-time position signal.

[0110] When the controller determines that the mechanical extension structure is in the seated position, the controller stops the first drive mechanism from working by controlling the switch; when the controller determines that the mechanical extension structure is not in the seated position, the controller controls the first drive mechanism to work by controlling the switch, and the first drive mechanism adjusts the position of the base relative to the base until the mechanical extension structure is in the seated position.

[0111] The sofa control method includes the sofa described in any of the above technical solutions, and the sofa further includes:

[0112] Gravity sensor, used to collect real-time gravity signals, is located in the seat cushion structure and / or backrest structure;

[0113] A first position sensor is electrically connected to a first drive mechanism, and the first position sensor is used to collect the first real-time position signal of the first drive mechanism.

[0114] The control switch is electrically connected to the first drive mechanism;

[0115] The timer module is used to calculate the real-time gravity signal acquisition time;

[0116] The controller, the first position sensor, the gravity sensor, the control switch, and the timer module are electrically connected to the controller respectively;

[0117] Sofa control methods include:

[0118] The controller presets the first designated position signal and the real-time gravity signal acquisition time. When the mechanical extension structure is not in the seated position, the controller acquires the real-time gravity signal for the first time through the gravity sensor.

[0119] When the gravity sensor fails to collect a real-time gravity signal for the first time, the timer module starts working. After the timer module reaches the real-time gravity signal collection time, the controller collects the first real-time position signal from the first position sensor and determines whether the mechanical extension structure is in a seated position by comparing the first designated position signal with the first real-time position signal. When the controller determines that the mechanical extension structure is not in a seated position, the controller controls the first drive mechanism to work through the control switch. The first drive mechanism adjusts the position of the base relative to the base until the mechanical extension structure is in a seated position.

[0120] The sofa control method includes the sofa described in any of the above technical solutions, and the sofa further includes:

[0121] Gravity sensor, used to collect real-time gravity signals, is located in the seat cushion structure and / or backrest structure;

[0122] A first position sensor is electrically connected to a first drive mechanism, and the first position sensor is used to collect the first real-time position signal of the first drive mechanism.

[0123] The control switch is electrically connected to the first drive mechanism;

[0124] The timer module is used to calculate the real-time gravity signal acquisition time;

[0125] The controller, the first position sensor, the gravity sensor, the control switch, and the timer module are electrically connected to the controller respectively;

[0126] Sofa control methods include:

[0127] The controller presets the first designated position signal and the real-time gravity signal acquisition time. When the mechanical extension structure is not in the seated position, the controller acquires the real-time gravity signal for the first time through the gravity sensor.

[0128] When the gravity sensor fails to collect a real-time gravity signal for the first time, the timer module starts working. After the timer module reaches the real-time gravity signal collection time, the controller collects the real-time gravity signal a second time through the gravity sensor.

[0129] When the gravity sensor fails to collect a real-time gravity signal for the second time, the controller collects the first real-time position signal from the first position sensor and determines whether the mechanical extension structure is in a seated position by comparing the first designated position signal with the first real-time position signal. When the controller determines that the mechanical extension structure is not in a seated position, the controller controls the first drive mechanism to work through the control switch. The first drive mechanism adjusts the position of the base relative to the base until the mechanical extension structure is in a seated position.

[0130] The sofa control method includes the sofa described in any of the above technical solutions, and the sofa further includes:

[0131] The headrest structure is movably mounted above the backrest structure;

[0132] The second drive mechanism has one end rotatably connected to the backrest structure and the other end rotatably connected to the headrest structure.

[0133] A control switch is electrically connected to the first drive mechanism and the second drive mechanism;

[0134] A first position sensor is electrically connected to a first drive mechanism, and the first position sensor is used to collect the first real-time position signal of the first drive mechanism.

[0135] The second position sensor is electrically connected to the second drive mechanism and is used to acquire the second real-time position signal of the second drive mechanism.

[0136] The controller, the first position sensor, the second position sensor, and the control switch are electrically connected to the controller respectively;

[0137] Sofa control methods include:

[0138] The controller presets a first designated position signal and a second designated position signal. The first position sensor transmits the first real-time position signal it collects to the controller, and the second position sensor transmits the second real-time position signal it collects to the controller. After comparing the first real-time position signal with the first designated position signal and comparing the second real-time position signal with the second designated position signal, the controller drives the first drive mechanism and the second drive mechanism to work through the control switch, so that the mechanical extension structure changes between the sitting position and the reclining position, and the second drive mechanism adjusts the position of the headrest structure relative to the backrest structure.

[0139] The sofa control method includes the sofa described in any of the above technical solutions, and the sofa further includes:

[0140] An anti-pinch sensor is used to detect the real-time electrical signal of the first drive mechanism;

[0141] The control switch is electrically connected to the first drive mechanism;

[0142] The controller, anti-pinch sensor, and control switch are electrically connected to the controller.

[0143] Sofa control methods include:

[0144] The controller presets a reference electrical signal. The anti-pinch sensor transmits the collected real-time electrical signal to the controller. The controller compares the real-time electrical signal with the reference electrical signal. When the real-time electrical signal is greater than or equal to the reference electrical signal, the controller drives the first drive mechanism through the control switch to change the mechanical extension structure to a lying position.

[0145] The sofa control method includes the sofa described in any of the above technical solutions, and the sofa further includes:

[0146] An anti-pinch sensor is used to detect the real-time electrical signal of the first drive mechanism;

[0147] The control switch is electrically connected to the first drive mechanism;

[0148] The controller, anti-pinch sensor, and control switch are electrically connected to the controller.

[0149] Sofa control methods include:

[0150] The controller presets a reference electrical signal. The anti-pinch sensor transmits the first real-time electrical signal and the second real-time electrical signal it collects to the controller. The controller compares the reference electrical signal with the difference between the first real-time electrical signal and the second real-time electrical signal. When the difference between the first real-time electrical signal and the second real-time electrical signal is greater than or equal to the reference electrical signal, the controller drives the first drive mechanism through the control switch to change the mechanical extension structure to a lying position.

[0151] The sofa control method includes the sofa described in any of the above technical solutions, and the sofa further includes:

[0152] The controller includes an interactive processing unit, which has a signal input terminal and a signal output terminal.

[0153] The display unit is used to display the navigation menu and sub-menus, and the signal output terminal of the interactive processing unit is connected to the display unit.

[0154] The operation button is connected to the signal input terminal of the interactive processing unit. Pressing or rotating an operation button will cause the display unit to display the corresponding menu information.

[0155] Sofa control methods include:

[0156] S01) Press the operation button in navigation mode to enter the submenu of the current menu item, enter the editing mode of the current menu item, or return to the parent menu of the current menu item. If entering the submenu or returning to the parent menu, return to step S03). If entering the editing mode, proceed to step S02.

[0157] S02) In edit mode, rotate the operation button to modify the parameters, and press the operation button to confirm that the parameter modification is complete.

[0158] S03) Press the operation button to enter the submenu or return to the previous menu.

[0159] Electronic devices, including:

[0160] A memory and a processor, wherein the processor is configured to run a program stored in the memory, wherein the program executes the sofa control method described in any of the above-described technical solutions when it runs.

[0161] This application has at least the following beneficial effects:

[0162] During the transition from the TV position to the reclining position, the front backrest support 42 rotates forward relative to the base 2; during the transition from the reclining position to the TV position, the front backrest support 42 rotates backward relative to the base 2. During the transition from the sitting position to the reclining position, the backrest panel 41 moves forward; during the transition from the reclining position to the sitting position, the backrest panel 41 moves backward. Because the front backrest support 42 rotates backward relative to the base 2 and the backrest panel 41 moves backward during the transition from the reclining position to the TV position, the front backrest support 42, through the backrest panel 41, drives the backrest structure 200 to move away from the seat cushion structure 300, thereby increasing the gap between the backrest structure 200 and the seat cushion structure 300. The backrest panel 41 and the front backrest support 42 move forward, but the front backrest support 42 does not rotate relative to the base 2. Because the front backrest support 42 does not rotate relative to the base 2, it does not cause the backrest panel 41 to rotate during the forward movement. In other words, during the transition from a seated position to a TV position, this application increases the difficulty of the backrest panel 41 moving backward relative to the seat cushion structure 300 by "preventing the front backrest support 42 from rotating the backrest panel 41." This structure further increases the reliability of the sofa's "zero-wall-leaning" function through the rotation of the "front backrest support 42."

[0163] Furthermore, in this application, the advantages of the guide sliding along the first or second guide surface and the guide sliding along the track include: 1. The guide is fixedly connected to the base or seat, therefore, during the sliding process of the guide along the track, it is difficult to generate motion noise between the guide and the base (or seat); 2. The surface of the guide (the surface of the guide that contacts the base) is covered by the track, therefore, it is difficult for foreign objects to actively fall onto its surface, that is, it is difficult for foreign objects to adhere to the surface of the guide that contacts the base; 3. The gravity of the guide is downward, and even after the guide is damaged, the gravity is still downward, therefore, regardless of whether the guide is damaged, its center of gravity will not shift during the sliding process of the guide along the track. In other words, the "guide sliding" technology effectively overcomes problems such as rolling noise, foreign object adhesion, and eccentric rolling, so as to improve the user experience, especially the user experience during the operation of the seat unit (the operation of the seat unit is the process of the base moving back and forth relative to the seat).

[0164] In this application, the mechanical extension structure includes a first drive unit that drives the base to slide along a track via a leg assembly. This structure reduces the manufacturing cost of the seat unit by "reducing the number of first drive units and reducing the number of on / off switches".

[0165] When the mechanical extension structure is in a seated position with a clearance fit between the track and the guide, the initial driving force required for the leg assembly to extend can be significantly reduced. When the mechanical extension structure is in a reclining position with a clearance fit between the track and the guide, the initial driving force required for the leg assembly to retract can be significantly reduced.

[0166] Since at least part of the second guide is located below the first guide, the orientation of the front of the base can be adjusted when the mechanical extension structure is in a seated position. Preferably, the front of the base can be tilted slightly downward, which makes it convenient for both young and old users to get up from the seat.

[0167] In this application, the driving force required for the movement of the leg assembly is significantly reduced by "at least part of the track and guide fitting with a clearance". After the driving force required for the movement of the leg assembly is reduced, the seat unit can adopt a single first drive device.

[0168] In this application, both reliability and manufacturing cost are balanced by using a method where "the guide slides along the first guide surface or the second guide surface" and "the seat unit adopts a single first drive device".

[0169] In this application, when the mechanical extension structure is in a seated position and the second guide abuts against the first limiting structure, the initial position of the first driving device is always determined, so as to reduce the probability of accumulated error of the first driving device.

[0170] The seat unit includes a backrest structure and a seat cushion structure. During the mechanical extension structure's transition from a sitting to a reclining position, the seat cushion structure continuously compresses the backrest structure. Therefore, when the mechanical extension structure is in the sitting position, even if the second guide impacts the first limiting structure, the user's perception will not be very noticeable. However, during the mechanical extension structure's transition from a reclining to a sitting position, the seat cushion structure moves away from the backrest structure. Therefore, when the mechanical extension structure is in the reclining position, the second guide impacts the first limiting structure through the cushioning pad, thus reducing the user's perception.

[0171] Currently, seat units are developing towards comfort and zero back rubbing. To achieve this goal, it is usually necessary to slow down the rate of increase in the vertical height difference between the front and rear of the base. "The angle between the first track and the horizontal plane is less than the angle between the second track and the horizontal plane, and the first track and the second track have the same tilt direction" can effectively improve the problem of the rapid increase in the vertical height difference during the movement of the base relative to the base.

[0172] When the guide is threadedly connected to the base, it facilitates easy assembly and disassembly. When the guide is threadedly connected to the base and in contact with the track surface, the "surface contact between the guide and the track" prevents the guide from rotating relative to the base during sliding. To ensure the reliability of the threaded connection between the guide and the base, a clearance fit is used between the guide and the track. The annular washer, which is held between the guide and the base, increases the connection strength between them.

[0173] The radial width of the annular gasket is greater than the width of the guide, allowing the annular gasket to slide along the track or base. This structure effectively prevents the base from being scratched by the base or track. Since the base surface is usually coated, the coating increases the base's corrosion resistance and oxidation resistance. Therefore, the ability of the annular gasket to slide along the track or base effectively extends the service life of the base.

[0174] When the mechanical extension structure is in the seated position and the backrest assembly is pressing against the seat cushion structure, the backrest assembly will prevent the user's hand from reaching between the backrest assembly and the base from top to bottom. This structure effectively reduces the probability of the user's hand being pinched by the seat unit.

[0175] When the mechanical extension structure is in a reclining position and the backrest assembly is pressing against the seat cushion structure, the backrest assembly can prevent the user's hand from reaching between the backrest assembly and the base from top to bottom in the reclining position; while when the mechanical extension structure is in a reclining position and there is a gap between the backrest assembly and the seat cushion structure, the gap can reduce the probability that the backrest assembly will puncture the seat cushion structure in the sitting position.

[0176] When the inner side of the first vertical plate and the outer side of the second vertical plate are fixedly connected to the mounting plate, the deformation resistance of the connecting rod will be improved; and at least one connecting rod including the first angle iron and the second angle iron effectively improves the applicable scenarios of the connecting rod.

[0177] In related technologies, the mechanical extension structure is provided with two sets of leg components, which are connected by a connecting structure. The connecting structure is rotatably connected to the first drive rod on the first driver. However, the existing connecting structure is not rotatably connected to the base. That is to say, during the process of the leg components extending in front of the base (or the leg components retracting below the base), the connecting structure is suspended in the air throughout. At this time, the force required for the leg components to move relative to the base is directly provided by the connecting structure.

[0178] The leg assembly is fixedly connected to the connecting rod. During the transition between the sitting and lying positions, the first drive rod drives the connecting rod to rotate relative to the base via the swing plate, so that the connecting rod drives the leg assembly to extend in front of the base or retract below the base.

[0179] Because the link is rotatably connected to the base, the base provides support for the link throughout the entire process of the leg assembly extending in front of the base (or retracting under the base). This means that, during the process of the leg assembly extending in front of the base (or retracting under the base), the base can reduce at least part of the torque required for the link to drive the leg assembly. This structure is used to solve the problem of vibration that may occur when the link drives the leg assembly.

[0180] After the base is impacted by an external force, the base can transfer part of the impact force to the connecting rod through the support block, thereby improving the base's resistance to deformation. If the connecting rod is located below the support block, it can absorb the impact force from above the base; if the connecting rod is located on the side wall of the base, it can absorb the impact force from the side of the base. This structure is used to reduce the deformation amplitude of the base after being impacted by an external force.

[0181] The mounting channel is open at both ends and circumferentially closed, while the hook is open at both ends and circumferentially open. The circumferentially closed mounting channel can increase the deformation resistance of the rear of the base, especially since the mounting channel is located at the rear of the base, and the rear of the base is rotatably connected to the first actuator. When the mounting channel is set at the rear of the base, the hook is set at the front of the base to reduce the installation difficulty of the seat cushion elastic element.

[0182] In related technologies, the backrest decorative cover uses stitching to create an inwardly recessed decorative seam on the front of the backrest structure. However, this stitching method increases the assembly time required for the backrest structure. In this application, an inwardly recessed decorative groove is directly provided on the front of the backrest filling. The backrest decorative cover is inserted into the decorative groove, thus directly forming the decorative seam required for the backrest structure.

[0183] When the backrest decorative cover and the decorative groove are fixedly connected by Velcro, and the backrest decorative cover is detachably installed on the backrest frame, the backrest decorative cover can be cleaned, removed, and installed without the need for other tools.

[0184] When the decorative groove includes inclined groove walls and the cross-sectional area of ​​the groove opening is less than the cross-sectional area of ​​the groove bottom, the connection strength between the backrest decorative cover and the decorative groove will be increased to prevent the backrest decorative cover from easily separating from the backrest filling due to friction on the user's back.

[0185] Because "the first driver is rotatably connected to the rear of the base, and the first drive rod is rotatably connected to the swing plate," when a set of leg assemblies, the base, and the base are movably connected to a set of swing mechanisms, the leg assemblies can drive the base to slide relative to the base through the swing mechanisms. Of course, in this application, when the first driver is rotatably connected to the base, the swing mechanism is not required.

[0186] The height of a robotic vacuum cleaner is around 8cm. When the distance between the lowest point of the swing mechanism and the lower end of the support rod is ≥8cm, most robotic vacuum cleaners can directly enter under the seat unit.

[0187] The eccentric position of the second link is rotatably connected to the base, which, in conjunction with the first drive device, is used to adjust the sliding speed of the base relative to the base; to match the adjustment speed of the seat unit for users of different ages, the adjustment speed being the speed at which the mechanical extension structure switches back and forth between the sitting and reclining positions.

[0188] The groove is used to reduce the probability that the second fastener will collide with foreign objects during the transportation of the seat unit.

[0189] The first elastic element is used to increase the stability of the base during its movement relative to the base, and the second elastic element is used to increase the stability of the leg assembly during its movement relative to the base.

[0190] In related technologies, the first output shaft of the first driver is perpendicular to the first drive rod, which causes the first driver to be located on one side of the first drive rod, that is, the center of gravity of the first driver is not on the axis of the first drive rod.

[0191] In this application, since the axis of the first output shaft coincides with the axis of the first drive rod, the first driver and the first drive rod are located on the same straight line. This structure overcomes the problem of the first drive device driving the first drive rod to rotate axially under its own weight by overcoming the eccentric setting of the first drive device.

[0192] The requirement that "the cross-sectional area of ​​at least one air outlet is less than the cross-sectional area of ​​the air guide channel located between the air outlet and the air outlet" is used to increase the air velocity at the air outlet, while the air guide channel enables the ventilation function of the backrest structure.

[0193] When the backrest cover is made of cowhide, air vents are provided on the backrest cover to connect with the air outlet; when the backrest cover is made of technical fabric, the backrest cover can also be left without vents, allowing ventilation through the gaps in the technical fabric.

[0194] In addition to the massage airbags, eccentric wheels can also be installed on the backrest padding of the sofa to provide users with a massage function.

[0195] The signal acquisition module transmits the acquired control signals to the controller. Based on the control signals, the controller controls the first drive device through a control switch, so that the first drive device adjusts the position of the base relative to the base.

[0196] This structure allows the base to be adjusted relative to the base using voice signals (or wireless signals, which can come from remote controls, mobile phones, iPads, computers, etc.).

[0197] The control switch is connected to the second drive device, and the signal acquisition module transmits the acquired control signal to the controller. This structure enables the headrest to be adjusted relative to the backrest frame using voice or wireless signals.

[0198] In this application, the position of the first driving device is calibrated using a first sensor to avoid the accumulation of errors in the first driving device.

[0199] In related technologies, various seat units are disclosed. Each seat unit includes a backrest structure, a seat cushion structure, a leg rest structure, a mechanical extension structure, and a control switch. The mechanical extension structure has a sitting position and a reclining position. When the control switch controls the mechanical extension structure to change from a sitting position to a reclining position, the leg rest structure extends forward toward the seat cushion structure, and the backrest structure reclines backward. When the control switch controls the mechanical extension structure to change from a reclining position to a sitting position, the leg rest structure retracts downward toward the seat cushion structure, and the backrest structure returns to its original position.

[0200] However, existing mechanical extension structures require continuous button pressing to adjust the seat unit to the desired position; that is, mechanical extension structures cannot be adjusted to the user's desired position with a single button press.

[0201] In this application, the third sensor, in conjunction with the controller, enables the base to be adjusted to the user-preset position with a single click. The fourth sensor, in conjunction with the controller, enables the headrest to be adjusted to the user-preset position with a single click. Attached Figure Description

[0202] Figure 1 is a first front view of the mechanical extension structure in a preferred embodiment of this application (the mechanical extension structure is located in a seated position);

[0203] Figure 2 is a front view of the mechanical extension structure in a preferred embodiment of this application (the mechanical extension structure is located in the TV position);

[0204] Figure 3 is a first front view of the mechanical extension structure in a preferred embodiment of this application (the mechanical extension structure is located in a lying position);

[0205] Figure 4 is a front view of the backrest assembly (first structure), base, and part of the swing mechanism in the preferred embodiment of this application;

[0206] Figure 5 is a rear view of the backrest assembly (first structure), base, and part of the swing mechanism in the preferred embodiment of this application;

[0207] Figure 6 is a perspective view of the mechanical extension structure in a preferred embodiment of this application (the mechanical extension structure is located in a seated position);

[0208] Figure 7 is a perspective view of the backrest assembly (second structure) and part of the base in the preferred embodiment of this application;

[0209] Figure 8 is a front view of the first drive mechanism in a preferred embodiment of this application;

[0210] Figure 9 is a cross-sectional view at point DD in Figure 8;

[0211] Figure 10 is a rear view of the seat unit in a preferred embodiment of this application;

[0212] Figure 11 shows the control system of the sofa in a preferred embodiment of this application;

[0213] Figure 12 is a second front view of the mechanical extension structure in a preferred embodiment of this application (the mechanical extension structure is located in a seated position);

[0214] Figure 13 is a second front view of the mechanical extension structure in a preferred embodiment of this application (the mechanical extension structure is located in a lying position);

[0215] Figure 14 is a perspective view of the swing mechanism in a preferred embodiment of this application;

[0216] Figure 15 is a perspective view of the first type of mechanical extension structure in this application;

[0217] Figure 16 is a perspective view of the first structure of the sliding mechanism in this application;

[0218] Figure 17 is a front view of the seat unit in this application (the first mechanical extension structure is located in the sitting position);

[0219] Figure 18 is a front view of the first type of mechanical extension structure in this application (the mechanical extension structure is in a lying position);

[0220] Figure 19 is a perspective view of the second type of mechanical extension structure in this application;

[0221] Figure 20 is a front view of the second type of mechanical extension structure in this application (the mechanical extension structure is located in a seated position);

[0222] Figure 21 is a perspective view of the first type of mechanical extension structure in this application (the mechanical extension structure is located in a lying position);

[0223] Figure 22 is a cross-sectional view of the first structure of the sliding mechanism in this application;

[0224] Figure 23 is a cross-sectional view of the second structure of the sliding mechanism in this application;

[0225] Figure 24 is a cross-sectional view of the connecting rod, support block, and part of the base in this application;

[0226] Figure 25 is a cross-sectional view of the third structure of the sliding mechanism in this application;

[0227] Figure 26 is a structural schematic diagram of the backrest structure in this application;

[0228] Figure 27 is a schematic diagram of the structure of the first driving device, some control switches and external power supply in this application;

[0229] Figure 28 is a schematic diagram of the second drive device, some control switches and external power supply in this application;

[0230] Figure 29 is a schematic diagram of the circuit connection of the sofa in this application. Detailed Implementation

[0231] The technical solutions of the embodiments of this application will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of this application and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of this application.

[0232] Referring to Figures 1, 3, and 4, the mechanical extension structure 100 includes:

[0233] Base 1;

[0234] Base 2 is located above base 1;

[0235] Two sets of swing mechanisms 7, the base 2 and the base 1 are movably connected through the swing mechanisms 7;

[0236] Linkage rod 3, each set of swing mechanisms 7 is fixedly connected to the end of linkage rod 3;

[0237] Two sets of backrest components 4 are located behind the base 1 and the base 2;

[0238] Two sets of leg components 5 are located in front of the base 2;

[0239] The first drive mechanism 6 is used to drive the leg assembly 5 to move;

[0240] The mechanical extension structure 100 has a sitting position, a TV position, and a reclining position. During the process of changing from the sitting position to the reclining position, the first drive mechanism 6 drives the base 2 forward through the leg assembly 5, so that the leg assembly 5 extends in front of the base 2 and the backrest assembly 4 tilts backward relative to the base 2. During the process of changing from the reclining position to the sitting position, the first drive mechanism 6 drives the base 2 backward through the leg assembly 5, so that the leg assembly 5 retracts under the base 2 and the backrest assembly 4 returns to its original position relative to the base 2.

[0241] The base 2 is provided with a mounting surface, which includes a first mounting surface 221 and / or a second mounting surface 211. Each backrest assembly 4 includes a backrest plate 41 and a backrest front bracket 42. The backrest plate 41 and the base 2 are rotatably connected to the backrest front bracket 42.

[0242] During the transition from a seated position to a TV position, the backrest 41 and the front backrest support 42 move forward, while the front backrest support 42 does not rotate relative to the base 2. As shown in Figure 2, when the mechanical extension structure 100 is in the TV position, the angle between the center line of the front backrest support 42 and the second mounting surface 211 is b, where b > 90°. During the transition from a TV position to a reclining position, the backrest 41 moves forward, and the front backrest support 42 rotates relative to the base 2. As shown in Figure 3, when the mechanical extension structure 100 is in the reclining position, b < 90°.

[0243] As shown in Figure 10, in this embodiment, the base 2 includes a base plate 21 and a base frame 22. The base plate 21 has a second mounting surface 211, and the base frame 22 is mounted above the second mounting surface 211. The base frame 22 has a first mounting surface 221, and the seat cushion structure 300 is mounted above the first mounting surface 221. In this embodiment, the base plate 21 and the base frame 22 are fixedly connected by rivets or screws. In other embodiments of this application, the base plate 21 and the base frame 22 are welded together, or the base plate 21 and the base frame 22 are integrally formed. In other embodiments of this application, the base includes a base plate. When the base includes a base plate, the backrest assembly, the swing mechanism, the leg assembly, and the seat cushion structure are respectively connected to the base plate; or the base includes a base frame. When the base includes a base frame, the backrest assembly, the swing mechanism, the leg assembly, and the seat cushion structure are respectively connected to the base frame.

[0244] In this application, the second mounting surface 211 is parallel to the base frame 22, and the second mounting surface 211 is also parallel to the first mounting surface 221. Since the second mounting surface 211 and the first mounting surface 221 are parallel to each other, the "angle between the center line of the backrest front bracket 42 and the second mounting surface 211" can be measured from the "angle between the center line of the backrest front bracket 42 and the first mounting surface 221". In particular, when the substrate 21 and the base frame 22 are welded together, or when the substrate 21 and the base frame 22 are integrally formed, the "angle between the center line of the backrest front bracket 42 and the second mounting surface 211" can be measured from the "angle between the center line of the backrest front bracket 42 and the first mounting surface 221".

[0245] Based on the statements that "the angle b between the centerline of the front backrest support 42 and the second mounting surface 211 is greater than 90° when the mechanical extension structure 100 is in the TV position" and "the angle b between the centerline of the front backrest support 42 and the second mounting surface 211 is less than 90° when the mechanical extension structure 100 is in the reclining position", it can be known that: during the process of the mechanical extension structure 100 changing from the TV position to the reclining position, the front backrest support 42 rotates forward relative to the base 2; during the process of the mechanical extension structure 100 changing from the reclining position to the TV position, the front backrest support 42 rotates backward relative to the base 2.

[0246] During the transition from a sitting to a reclining position, the backrest 41 of the mechanical extension structure 100 moves forward; conversely, during the transition from a reclining to a sitting position, the backrest 41 moves backward. Because the front backrest support 42 rotates backward relative to the base 2 and the backrest 41 moves backward during the transition from a reclining to a TV position, the front backrest support 42, through the backrest 41, drives the backrest structure 200 away from the seat cushion structure 300, thereby increasing the gap between the backrest structure 200 and the seat cushion structure 300. In other words, during the transition from a reclining to a TV position, this application addresses the problem of sofas trapping users' clothing by "increasing the gap between the backrest structure 200 and the seat cushion structure 300."

[0247] In this application, the “seat cushion structure 300” is also known as a sofa seat cushion in daily life, and the “backrest structure 200” is also known as a sofa backrest in daily life.

[0248] During the transition from a seated position to a TV position, the backrest 41 and the front backrest support 42 move forward, while the front backrest support 42 remains stationary relative to the base 2. Conversely, during the transition from a TV position to a seated position, the backrest 41 and the front backrest support 42 move backward, while the front backrest support 42 remains stationary relative to the base. In other words, during the transition from a TV position to a seated position, this application addresses the issue of the sofa trapping the user's clothing by maintaining a gap between the backrest structure 200 and the seat cushion structure 300.

[0249] During the transition from a seated position to a TV position, the mechanical extension structure 100 moves the backrest 41 and the front backrest support 42 forward, while the front backrest support 42 remains stationary relative to the base 2. Because the front backrest support 42 does not rotate relative to the base 2, it does not cause the backrest 41 to rotate during the forward movement. In other words, by preventing the front backrest support 42 from rotating the backrest 41 during the transition from a seated position to a TV position, this application increases the difficulty of the backrest 41 moving backward relative to the seat cushion structure 300. This structure further enhances the reliability of the sofa's "zero-wall-leaning" function through the rotation of the front backrest support 42.

[0250] As shown in Figures 4 and 5, the backrest panel 41 is provided with an installation position 411 for installing the backrest structure 200 and a transition position 412 for rotatably connecting with the front support 42 of the backrest. The angle between the line connecting the midpoint of the installation position 411 and the midpoint of the transition position 412 and the second mounting surface 211 is α. The angle α when the mechanical extension structure 100 is in the TV position is greater than the angle α when the mechanical extension structure 100 is in the reclining position.

[0251] Since the position a of the mechanical extension structure 100 in the TV position is greater than the position a of the mechanical extension structure 100 in the reclining position, during the transition from the reclining position to the TV position, the backrest 41 moves away from the second mounting surface 211. After the backrest 41 moves away from the second mounting surface 211, the backrest structure 200 moves with the backrest 41 in the same direction, that is, the backrest structure 200 moves away from the seat cushion structure 300. In other words, during the transition from the reclining position to the TV position, this application solves the problem of the sofa trapping the user's clothes by having the backrest structure 200 move away from the seat cushion structure 300 along with the backrest 41.

[0252] As shown in Figure 4, a first limiting rod 10 is provided on the base 2. When the mechanical extension structure 100 is in the sitting position, TV position, and lying position, the first limiting rod 10 abuts against the front support 42 of the backrest. During the process of the mechanical extension structure 100 changing from the sitting position to the TV position, the first limiting rod 10 abuts against the front support 42 of the backrest. During the process of the mechanical extension structure 100 changing from the TV position to the lying position, the first limiting rod 10 does not abut against the front support 42 of the backrest.

[0253] When the mechanical extension structure 100 is in the seated position, when the mechanical extension structure 100 is in the TV position, and during the process of the mechanical extension structure 100 changing from the seated position to the TV position, the first limiting rod 10 always abuts against the front support 42 of the backrest, so as to ensure that the position of the rotational connection (transition position 412) between the backrest panel 41 and the front support 42 of the backrest relative to the base 2 does not change; that is, during the process of the mechanical extension structure 100 changing from the seated position to the TV position, this application prevents the backrest panel 41 from moving relative to the front support 42 of the backrest, so that the relative position of the backrest structure 200 relative to the front support 42 does not change.

[0254] As shown in Figure 3, when the mechanical extension structure 100 is in the lying position, the first limiting rod 10 abuts against the front support 42 of the backrest. This structure enables the first limiting rod 10 to support and limit the front support 42 of the backrest when the mechanical extension structure 100 is in the lying position.

[0255] Similarly, as shown in Figure 1, when the mechanical extension structure 100 is in the seated position, the first limiting rod 10 abuts against the front support 42 of the backrest. This structure allows the first limiting rod 10 to support and limit the front support 42 of the backrest when the mechanical extension structure 100 is in the seated position. As shown in Figure 2, when the mechanical extension structure 100 is in the TV position, the first limiting rod 10 abuts against the front support 42 of the backrest. This structure allows the first limiting rod 10 to support and limit the front support 42 of the backrest when the mechanical extension structure 100 is in the TV position.

[0256] As shown in Figure 4, the length of the front backrest support 41 above the rotatable connection between the front backrest support 41 and the base 2 is greater than the length of the front backrest support 41 below the rotatable connection between the front backrest support 41 and the base 2. As shown in Figure 2, when the mechanical extension structure 100 is in the TV position, the transition position 412 is located behind the first limiting rod 10, the first limiting rod 10 abuts against the front backrest support 42, and prevents the front backrest support 42 from moving downward. As shown in Figure 3, when the mechanical extension structure 100 is in the reclining position, the transition position 412 is located in front of the first limiting rod 10, the first limiting rod 10 abuts against the front backrest support 42, and prevents the front backrest support 42 from moving upward.

[0257] In this application, since the length of the backrest front support 42 above the rotatable connection between the backrest front support 42 and the base 2 is greater than the length of the backrest front support 42 below the rotatable connection between the backrest front support 42 and the base 2, the backrest structure 200 can achieve a large-angle backward flip within a short distance during the process of the mechanical extension structure 100 changing from the TV position to the reclining position.

[0258] Since the transition position 412 is located behind the first limiting rod 10, when the first limiting rod 10 abuts against the front support 42 of the backrest and prevents the front support 42 of the backrest from moving downward, the first limiting rod 10 provides resistance to the front support 42 of the backrest so as to ensure that the backrest structure 200 does not move backward when the mechanical extension structure 100 is in the TV position.

[0259] Since the transition position 412 is located in front of the first limiting rod 10, when the first limiting rod 10 abuts against the front support 42 of the backrest and prevents the front support 42 of the backrest from moving upward, the first limiting rod 10 provides a pulling force to the front support 42 of the backrest so that the backrest structure 200 will not move backward when the mechanical extension structure 100 is in the reclining position.

[0260] As shown in Figures 1, 3, and 6, each set of swing mechanisms 7 includes:

[0261] The front support plate 71 is rotatably connected to the base 1;

[0262] The rear support plate 72 is rotatably connected to the base 1;

[0263] The inner swing assembly 73, base 2, backrest assembly 4, leg assembly 5, front support plate 71 and rear support plate 72 are movably connected to the inner swing assembly 73 respectively;

[0264] The external swing assembly 74 is movably connected to the leg assembly 5, and the linkage rod 3 is fixedly connected to the external swing assembly 74.

[0265] The backrest assembly 4 also includes a backrest support 43 rotatably connected to the backrest plate 41, and the inner swing assembly 73 includes a rear swing plate 731. The base 2, the rear support plate 72, and the backrest support 43 are rotatably connected to the rear swing plate 731.

[0266] As shown in Figure 3, the backrest assembly 4 also includes a backrest connecting bracket 44, one end of which is rotatably connected to the front backrest bracket 41, and the other end of which is rotatably connected to the rear swing plate 731.

[0267] During the process of changing from a sitting position to a TV position, the front support 41 of the backrest remains in a fixed position relative to the backrest connecting support 44; during the process of changing from a TV position to a reclining position, the front support 41 of the backrest rotates relative to the backrest connecting support 44.

[0268] In related technologies, when the mechanical extension structure is in the TV position, the angle between the front of the backrest structure and the lower end face of the base is 110°; when the mechanical extension structure is in the reclining position, the angle between the front of the backrest structure and the lower end face of the base is 160°. When the backrest assembly includes a front backrest bracket, the front backrest bracket increases the distance the backrest panel moves forward when the mechanical extension structure is in the reclining position, so that the mechanical extension structure can adjust the angle between the front of the backrest structure and the lower end face of the base from 110° to 160° within a short distance.

[0269] In this application, the first limiting rod 10 constrains the rotation angle of the front backrest bracket 41 relative to the base 2. After the rotation angle of the front backrest bracket 41 relative to the base 2 is constrained, the front backrest bracket 41 constrains the rotation angle of the rear swing plate 731 relative to the base 2 through the backrest connecting bracket 44. Since the mechanical extension structure changes from the TV position to the reclining position, the base 2 adjusts the angle between the second mounting surface 211 and the lower end surface of the base 1 through the rear swing plate 731 (the angle between the second mounting surface 211 and the lower end surface of the base 1 determines the angle between the seat cushion structure 300 and the lower end surface of the base 1), when the front backrest bracket 41 constrains the rotation angle of the rear swing plate 731 relative to the base 2 through the backrest connecting bracket 44, the angle between the seat cushion structure 300 and the lower end surface of the base 1 is also constrained. In other words, during the process of the mechanical extension structure changing from the TV position to the reclining position, this application achieves the control of the angle between the seat cushion structure 300 and the lower end face of the base 1 when the mechanical extension structure 100 is in the reclining position by "adding a backrest connecting bracket 44".

[0270] As shown in Figures 1 and 2, a second limiting rod 20 is provided on the backrest panel 41. When the mechanical extension structure 100 is in the sitting position and the TV position, the second limiting rod 20 abuts against the backrest support 43. During the process of the mechanical extension structure 100 changing from the sitting position to the TV position, the second limiting rod 20 abuts against the backrest support 43.

[0271] When the mechanical extension structure 100 is in the seated position, when the mechanical extension structure 100 is in the TV position, and during the process of the mechanical extension structure 100 changing from the seated position to the TV position, the second limiting rod 20 is always in contact with the backrest support 43 to ensure that the position of the rotational connection 413 between the backrest panel 41 and the backrest support 43 relative to the base 2 does not change; that is, during the process of the mechanical extension structure 100 changing from the seated position to the TV position, this application prevents the backrest panel 41 from moving relative to the backrest support 43 so that the relative position of the backrest structure 200 relative to the backrest support 43 does not change.

[0272] In this application, the backrest panel 41 is rotatably connected to the front backrest support 42 and the backrest support 43. When the mechanical extension structure 100 is in the sitting position, when the mechanical extension structure 100 is in the TV position, and during the process of the mechanical extension structure 100 changing from the sitting position to the TV position, the position of the rotatable connection 412 between the backrest panel 41 and the front backrest support 42 relative to the base 2 does not change, and the position of the rotatable connection 413 between the backrest panel 41 and the backrest support 43 relative to the base 2 does not change. That is to say, when the mechanical extension structure 100 is in the sitting position, when the mechanical extension structure 100 is in the TV position, and during the process of the mechanical extension structure 100 changing from the sitting position to the TV position, this application achieves the function of zero wall contact with the sofa by "preventing the position of the backrest panel 41 relative to the base 2 from changing".

[0273] As shown in Figure 3, the front support 42 of the backrest is provided with a third limiting rod 30. When the mechanical extension structure 100 is in the TV position, the backrest 41 does not abut against the third limiting rod 30. The base 2 is provided with a first limiting rod 10. When the mechanical extension structure 100 is in the reclining position, the back support 43 of the backrest does not abut against the second limiting rod 20, the backrest 41 abuts against the third limiting rod 30, and the front support 42 of the backrest abuts against the first limiting rod 10.

[0274] During the process of the mechanical extension structure changing from the TV position to the lying position, the backrest 41 does not abut against the third limiting rod 30, the front backrest bracket 42 does not abut against the first limiting rod 10, and the backrest bracket 43 does not abut against the second limiting rod 20.

[0275] Since the backrest 41 does not abut against the third limiting rod 30 when the mechanical extension structure 100 is in the TV position, the backrest 41 moves toward the third limiting rod 30 during the process of the mechanical extension structure changing from the TV position to the reclining position. This structure realizes that the angle between the front of the backrest structure 200 and the horizontal plane is adjusted from 110° to 160°.

[0276] When the mechanical extension structure 100 is in a reclining position, the backrest 41 abuts against the third limiting rod 30, and the front backrest support 42 abuts against the first limiting rod 10, so that the third limiting rod 30 supports the backrest 41 and the first limiting rod 10 supports the front backrest support 42. In other words, when the mechanical extension structure 100 is in a reclining position, the first limiting rod 10 constrains the position of the front backrest support 42 against the base 2, and the third limiting rod 30 constrains the position of the backrest 41 relative to the front backrest support 42, thus constraining the position of the backrest 41 relative to the base 2. When the position of the backrest 41 relative to the base 2 is constrained, the position of the backrest structure 200 relative to the seat cushion structure 300 is also constrained.

[0277] Preferably, as shown in Figure 5, the base 2 is provided with an upward-facing upper groove 212. When the mechanical extension structure 100 is in a reclining position, the backrest 41 abuts against the third limiting rod 30, and the third limiting rod 30 abuts against the groove wall of the upper groove 212; that is, the base 2 provides support for the backrest 41 through the third limiting rod 30.

[0278] As shown in Figures 4 and 6, the rotatable connection between the rear support plate 72 and the rear swing plate 731 is located above the rotatable connection between the backrest connecting bracket 44 and the rear swing plate 731, and the rotatable connection between the base 2 and the rear swing plate 731 is located below the rotatable connection between the backrest connecting bracket 44 and the rear swing plate 72.

[0279] The rear swing plate 731 is provided with a fourth limiting rod 7312. When the mechanical extension structure 100 is in a sitting position, when the mechanical extension structure 100 is in a TV position, and during the process of the mechanical extension structure 100 changing from a sitting position to a TV position, the fourth limiting rod 7312 abuts against the base 2; when the mechanical extension structure 100 is in a lying position, and during the process of the mechanical extension structure 100 changing from a TV position to a lying position, the fourth limiting rod 7312 does not abut against the base 2.

[0280] When the mechanical extension structure 100 is in a seated position, in a TV position, and during the process of changing from a seated position to a TV position, the fourth limiting rod 7312 abuts against the base 2 to calibrate the position of the rear swing plate 731 relative to the base 2. During the process of changing from a TV position to a reclining position, the fourth limiting rod 7312 does not abut against the base 2, so that the rear swing plate 731 can change the position of the base 2 relative to the base 1.

[0281] Since the rotatable connection between the rear support plate 72 and the rear swing plate 731 is located above the rotatable connection between the backrest connecting bracket 44 and the rear swing plate 731, and the rotatable connection between the base 2 and the rear swing plate 731 is located below the rotatable connection between the backrest connecting bracket 44 and the rear swing plate 731, during the process of the mechanical extension structure 100 changing from the TV position to the reclining position, the rear swing plate 731 transmits the thrust through the backrest connecting bracket 44 and the front backrest bracket 42 to the backrest plate 41 through its own swing, so as to realize that the backrest plate 41 changes the position of the backrest structure 200 relative to the seat cushion structure 300.

[0282] As shown in Figures 1 and 3, a fifth limiting rod 50 is provided on the base 2, and the inner swing assembly 73 also includes:

[0283] The front swing plate 732 is rotatably connected to the front support plate 71 at one end and rotatably connected to the base plate 2 at the other end.

[0284] The swing connecting plate 734 is rotatably connected at one end to the front swing plate 732 and at the other end to the rear swing plate 731.

[0285] The intermediate swing plate 733 is rotatably connected to the base plate 2.

[0286] The upper swing plate 735 has one end rotatably connected to the front support plate 71, and the other end rotatably connected to the middle swing plate 733.

[0287] The lower swing plate 736 is rotatably connected at one end to the leg assembly 5 and at the other end to the middle swing plate 733.

[0288] Specifically, when the mechanical extension structure 100 is in a seated position, when the mechanical extension structure 100 is in a TV position, and during the process of the mechanical extension structure 100 changing from a seated position to a TV position, the fifth limiting rod 50 abuts against the front swing plate 732, and the fifth limiting rod 50 is located above the front swing plate 732.

[0289] Preferably, as shown in Figure 3, the lower swing plate 736 is rotatably connected to the second connecting rod 52.

[0290] When the fifth limiting rod 50 abuts against the front swing plate 732 and is located above the front swing plate 732, the front swing plate 732 can support the fifth limiting rod 50, thereby supporting the base 2 through the fifth limiting rod 50. Since the front swing plate 732 supports the base 2 through the fifth limiting rod 50, the base 2 can always receive the supporting force from the front swing plate 732 when the mechanical extension structure 100 is in the seated position, when the mechanical extension structure 100 is in the TV position, and during the process of the mechanical extension structure 100 changing from the seated position to the TV position.

[0291] As shown in Figures 1, 3, and 6, the rear swing plate 731 is provided with a fourth limiting rod 7312. When the mechanical extension structure 100 is in a sitting position, when the mechanical extension structure 100 is in a TV position, and during the process of the mechanical extension structure 100 changing from a sitting position to a TV position, the fourth limiting rod 7312 supports the base 2, and the front swing plate 732 supports the fifth limiting rod 50. When the mechanical extension structure 100 is in a lying position, and during the process of the mechanical extension structure 100 changing from a TV position to a lying position, the fourth limiting rod 7312 does not abut against the base 2, and the fifth limiting rod 50 does not abut against the front swing plate 732.

[0292] When the fourth limiting rod 7312 supports the base 2 and the front swing plate 732 supports the fifth limiting rod 50, the rear swing plate 731 prevents the base 2 from sinking relative to the base 1 through the fourth limiting rod 7312, and the front swing plate 732 prevents the base 2 from sinking relative to the base 1 through the fifth limiting rod 50.

[0293] As shown in Figure 1, the front swing plate 732 is located in front of the rear swing plate 731;

[0294] The second mounting surface 211 is located below the fifth limiting rod 50, and / or the second mounting surface 211 is located above the fourth limiting rod 7312.

[0295] When the second mounting surface 211 is located below the fifth limiting rod 50, the support force height of the seat cushion structure 300 will be lower than that of the base 2, thereby increasing the stability of the seat cushion structure 300 relative to the base 2.

[0296] When the second mounting surface 211 is above the fourth limiting rod 7312, the support height of the seat cushion structure 300 will be higher than that of the base 2. Since the front swing plate 732 is located in front of the rear swing plate 731, when the second mounting surface 211 is below the fifth limiting rod 50 and above the fourth limiting rod 7312, the center of gravity of the seat cushion structure 300 will shift forward. When the user lies on the sofa, the backrest structure 200 supports the user's back, and the seat cushion structure 300 supports the user's buttocks and legs. In this application, the center of gravity of the seat cushion structure 300 is shifted forward, increasing the distance between the center of gravity of the seat cushion structure 300 and the center of gravity of the backrest structure 200 to reduce the probability of the sofa tipping over.

[0297] As shown in Figures 1 and 6, the second mounting surface 211 is located on the outside of the base 2, and / or the fifth limiting rod 50 and the front swing plate 732 are located on the inside of the base 2.

[0298] In related technologies, seat cushion structures are developing towards a wider seat width, that is, the width of the seat cushion structure increases by 10cm, and further develops towards 80cm or more. In this application, the "second mounting surface 211 is located on the outside of the base 2" to change the mounting position of the seat cushion structure 300 on the base 2. By moving the mounting position of the seat cushion structure 300 outward, the base 2 can increase the stability of the seat cushion structure 300 without changing the width of the base 2.

[0299] In this application, since the second mounting surface 211 is located on the outside of the base 2, when the fifth limiting rod 50 and the front swing plate 732 are located on the inside of the base 2, the movement of the front swing plate 732 will not interfere with the seat structure 300.

[0300] As shown in Figure 1, the front swing plate 732 is provided with a sixth limiting rod 60, and the middle swing plate 733 is provided with a ninth limiting rod 7331. When the mechanical extension structure 100 is in the sitting position, the upper end face of the front part of the swing link 734 supports the sixth limiting rod 60, and the upper end face of the rear part of the swing link 734 abuts against the ninth limiting rod 7331. When the mechanical extension structure 100 is in the TV position, and during the process of the mechanical extension structure 100 changing from the sitting position to the TV position, the upper end face of the front part of the swing link 734 supports the sixth limiting rod 60, and the ninth limiting rod 7331 separates from the swing link 734.

[0301] When the mechanical extension structure 100 is in a seated position, the fifth limiting rod 50 is located between the front support plate 71 and the sixth limiting rod 60.

[0302] In related technologies, when the mechanical extension structure is in a seated position, some users like to jump onto the sofa or sit on it forcefully. However, according to user feedback, when a user jumps onto the sofa or sits on it forcefully, the backrest structure will receive an impact force from the user; this impact force will cause the backrest panel to move backward, and the backward movement of the backrest panel will cause the rear swing plate to rotate upward. In this application, when the mechanical extension structure 100 is in a seated position, the upper end face of the front part of the swing link 734 supports the sixth limiting rod 60, and the upper end face of the rear part of the swing link 734 abuts against the ninth limiting rod 7331. The ninth limiting rod 7331 will prevent the rear part of the swing link 734 from moving upward. After the rear part of the swing link 734 is prevented from moving upward, the rear swing plate 731 will not be able to rotate upward relative to the base 2, so as to prevent the backrest assembly 4 from driving the backrest structure 200 to fall backward relative to the seat cushion structure 300. The sixth limiting rod 60 will prevent the front part of the swing link 734 from moving upward. The sixth limiting rod 60 and the ninth limiting rod 7331 prevent the swing link 734 from moving upward from both the front and rear positions.

[0303] When the mechanical extension structure 100 is in a seated position, since the fifth limiting rod 50 is located between the front support plate 71 and the sixth limiting rod 60, when the user jumps onto the sofa or sits down forcefully on the sofa, the user's impact force is transmitted from the seat cushion structure 300 through the fifth limiting rod 50 and the front swing plate 732 to the front support plate 71 and the swing linkage 734. That is, the swing linkage 734 provides support force for the front swing plate 732 at the sixth limiting rod 60.

[0304] Since the other end of the front swing plate 732 is rotatably connected to the substrate 2 and the upper end face of the swing connecting rod 734 supports the sixth limiting rod 60, the sixth limiting rod 60 is located between the "other end of the front swing plate 732 rotatably connected to the substrate 2" and the "one end of the swing connecting rod 734 rotatably connected to the front swing plate 73". In other words, the setting of the sixth limiting rod 60 can effectively reduce the impact force received by the "other end of the front swing plate 732 rotatably connected to the substrate 2" and the "one end of the swing connecting rod 734 rotatably connected to the front swing plate 73".

[0305] In this application, the mechanical extension structure 100 also includes a support mechanism 8, which includes a first support plate 81, a second support plate 82, and a roller 811. As shown in Figure 2, one end of the second support plate 82 is rotatably connected to the base 1, and the other end of the second support plate 82 is rotatably connected to the first support plate 81. One end of the first support plate 81 is rotatably connected to the front support plate 71, and the other end of the first support plate 81 is provided with a roller 811. When the mechanical extension structure 100 is in the TV position, when the mechanical extension structure 100 is in the lying position, and during the process of the mechanical extension structure 100 changing from the TV position to the lying position, the ninth limiting rod 7331 separates from the swing connecting plate 734, and the lower end surface of the roller 811 is not higher than the lower end surface of the base 1. When the mechanical extension structure 100 is in the TV position, when the mechanical extension structure 100 is in the reclining position, and during the process of the mechanical extension structure 100 changing from the TV position to the reclining position, the center of gravity of the sofa will shift forward. At this time, the casters 811 will contact the ground to solve the problem of the sofa easily tipping over.

[0306] Of course, in this application, the connection positions of the first support plate and the second support plate can also be interchanged: that is, the mechanical extension structure 100 also includes a first support plate and a second support plate, one end of the second support plate is rotatably connected to the base, the other end of the second support plate is provided with a roller, one end of the first support plate is rotatably connected to the front support plate, and the other end of the first support plate is rotatably connected to the second support plate.

[0307] As shown in Figure 2, the front support 42 of the backrest is located behind the middle swing plate 733. This structure avoids interference between the front support 42 of the backrest and the middle swing plate 733. When the mechanical extension structure 100 is in the sitting position, the rotatable connection 7332 between the middle swing plate 733 and the base 2 is located above the ninth limit rod 7331; when the mechanical extension structure 100 is in the reclining position, the rotatable connection 7332 between the middle swing plate 733 and the base 2 is located below the ninth limit rod 7331.

[0308] In this application, the first structure of the backrest assembly 4 includes: a backrest panel 41, a front backrest bracket 42, a rear backrest bracket 43, and a backrest connecting bracket 44. As shown in Figure 7, the backrest assembly 4 also includes a second structure, namely, the backrest assembly 4 also includes a backrest plate 41, a front backrest bracket 42, a rear backrest bracket 43, a first backrest bracket 45, a second backrest bracket 46, and a third backrest bracket 47. The backrest plate 41 is fixedly connected to the backrest structure 200. One end of the front backrest bracket 42 is rotatably connected to the backrest plate 41, and the other end of the front backrest bracket 42 is rotatably connected to the base 2. One end of the rear backrest bracket 43 is rotatably connected to the backrest plate 41, and the other end of the rear backrest bracket 43 is rotatably connected to the base 2. One end of the first backrest bracket 45 is rotatably connected to the front backrest bracket 42, and the other end of the first backrest bracket 45 is rotatably connected to one end of the second backrest bracket 46. The second backrest bracket 46 is rotatably connected to the base 2. The other end of the second backrest bracket 46 is rotatably connected to one end of the third backrest bracket 47, and the other end of the third backrest bracket 47 is rotatably connected to the base 1.

[0309] The backrest front support 42 is provided with a third limiting rod 30. When the mechanical extension structure 100 is in a sitting position or in a TV position, the second backrest support 46 abuts against the third limiting rod 30. When the mechanical extension structure 100 is in a reclining position or during the process of changing the mechanical extension structure 100 from the TV position to the reclining position, the second backrest support 46 does not abut against the third limiting rod 30.

[0310] In this application, as shown in Figure 7, when the second backrest bracket 46 abuts against the third limiting rod 30, the second backrest bracket 46 prevents the front backrest bracket 42 from rotating relative to the base 2; that is, when the mechanical extension structure 100 is in a sitting position and the second backrest bracket 46 abuts against the third limiting rod 30, the second backrest bracket 46 prevents the front backrest bracket 42 from rotating relative to the base 2, thereby preventing the backrest plate 41 from driving the backrest structure 200 to move relative to the seat cushion structure 300.

[0311] Preferably, as shown in Figure 7, when the mechanical extension structure 100 is in the TV position and the second backrest bracket 46 abuts against the third limiting rod 30, the second backrest bracket 46 prevents the backrest structure 200 from moving relative to the seat cushion structure 300 by preventing the backrest front bracket 42 from rotating relative to the base 2.

[0312] In this application, as shown in Figure 7, a seventh limiting rod 70 is provided on the backrest panel 41. When the mechanical extension structure 100 is in a sitting position, when the mechanical extension structure 100 is in a TV position, and during the process of the mechanical extension structure 100 changing from a sitting position to a reclining position, the seventh limiting rod 70 does not abut against the front support 42 of the backrest; when the mechanical extension structure 100 is in a reclining position, the seventh limiting rod 70 abuts against the front support 42 of the backrest.

[0313] And / or, the base 2 is provided with an eighth limiting rod 80. When the mechanical extension structure 100 is in a sitting position, when the mechanical extension structure 100 is in a TV position, or during the process of the mechanical extension structure 100 changing from a sitting position to a reclining position, the eighth limiting rod 80 does not abut against the front support 42 of the backrest; when the mechanical extension structure 100 is in a reclining position, the eighth limiting rod 80 abuts against the front support 42 of the backrest.

[0314] In this application, as shown in Figure 7, when the seventh limiting rod 70 abuts against the front support 42 of the backrest, the seventh limiting rod 70 prevents the backrest panel 41 from moving; that is, when the mechanical extension structure 100 is in a reclining position and the seventh limiting rod 70 abuts against the front support 42 of the backrest, the seventh limiting rod 70 prevents the backrest structure 200 from moving relative to the seat cushion structure 300 by preventing the backrest panel 41 from moving. Similarly, when the eighth limiting rod 80 abuts against the front support 42 of the backrest, the eighth limiting rod 80 prevents the front support 42 of the backrest from moving; that is, when the mechanical extension structure 100 is in a reclining position and the eighth limiting rod 80 abuts against the front support 42 of the backrest, the eighth limiting rod 80 prevents the backrest panel 41 from driving the backrest structure 200 to move relative to the seat cushion structure 300 by preventing the front support 42 of the backrest from moving.

[0315] Of course, as shown in Figure 7, most preferably, when the mechanical extension structure 100 is in the reclining position, the seventh limiting rod 70 abuts against the front support 42 of the backrest, and the eighth limiting rod 80 abuts against the front support 42 of the backrest, so that the front support 42 of the backrest is clamped between the seventh limiting rod 70 and the eighth limiting rod 80. The eighth limiting rod 80 limits the base 2 to the front support 42 of the backrest, and the seventh limiting rod 70 limits the front support 42 of the backrest to the backrest panel 41.

[0316] In this application, the backrest panel 41 is located inside the base 2, and an anti-pinch plate (not marked) is provided on the outer side of the backrest panel 41. Part of the front backrest bracket 42 and part of the rear backrest bracket 43 correspond to the anti-pinch plate, meaning the anti-pinch plate covers part of the front backrest bracket 42 and part of the rear backrest bracket 43. This structure is used to prevent the front backrest bracket 42 from pinching the user during rotation relative to the backrest panel 41, and to prevent the rear backrest bracket 43 from pinching the user during rotation relative to the backrest panel 41. Furthermore, the anti-pinch plate is located within the projection of the backrest structure 200 onto the horizontal plane, and the anti-pinch plate is located inside the seat cushion structure 300; that is, the backrest structure 200 and the seat cushion structure 300 cooperate to prevent the backrest assembly 4 from pinching the user. Normally, the base 2 is located inside the seat cushion structure 300.

[0317] As shown in Figure 6, the external swing assembly 74 includes a first swing plate 741 and a second swing plate 742. One end of the first swing plate 741 is fixedly connected to the linkage rod 3, and the other end of the first swing plate 741 is rotatably connected to one end of the second swing plate 742. The other end of the second swing plate 742 is rotatably connected to the leg assembly 5. Preferably, the second swing plate 742 is rotatably connected to the second connecting rod 52.

[0318] As shown in Figures 2, 5, and 6, the base 2 is provided with a clearance hole 241. The linkage rod 3 passes through the clearance hole 241 and is fixedly connected to one end of the first swing plate 741. When the linkage rod 3 passes through the clearance hole 241, a bushing (unmarked) is provided between the linkage rod 3 and the clearance hole 241. The bushing is provided with an anti-rotation protrusion (unmarked), and the clearance hole 241 is provided with an anti-rotation groove 2141. The anti-rotation protrusion is inserted into the anti-rotation groove 2141 to prevent the bushing from rotating relative to the clearance hole 241.

[0319] As shown in Figures 6 and 10, a third support rod 111 is provided on the base 1. When the mechanical extension structure 100 is in a reclining position, the rear support plate 72 abuts against the third support rod 111, that is, the third support rod 111 supports the rear support plate 72 to prevent the rear support plate 72 from rotating when the mechanical extension structure 100 is in a reclining position. When the mechanical extension structure 100 is in a sitting position, when the mechanical extension structure 100 is in a TV position, or during the transition between the sitting and reclining positions, the rear support plate 72 does not abut against the third support rod 111.

[0320] As shown in Figures 2 and 3, each leg assembly 5 includes a first link 51, a second link 52, a third link 53, a fourth link 54, and a main leg rest plate 55. The first link 51 and the second link 52 are rotatably connected to the base 2, the first link 51, the second link 52, and the main leg rest plate 55 are rotatably connected to the third link 53, and the first link 51 and the main leg rest plate 55 are rotatably connected to the fourth link 54. The third link 53 is equipped with a second support rod 531. When the mechanical extension structure 100 is in the TV position, when the mechanical extension structure 100 is in the lying position, and during the transition between the TV position and the lying position, the first link 51 abuts against the second support rod 531 to support the first link 51.

[0321] As shown in Figures 2 and 3, each leg assembly 5 also includes a fifth link 56, a sixth link 57, a seventh link 59, and a secondary footrest 58. The fourth link 54, the sixth link 57, and the secondary footrest 58 are rotatably connected to the fifth link 56, the sixth link 57 and the seventh link 59 are rotatably connected to the main footrest 55, and the seventh link 59 is rotatably connected to the secondary footrest 58. The sixth link 57 is used to control the movement posture of the secondary footrest 55.

[0322] As shown in Figures 2 and 3, the fifth link 56 is provided with a tenth limiting rod 561. When the mechanical extension structure 100 is in a sitting position, the tenth limiting rod 561 abuts against the secondary footrest 58; when the mechanical extension structure 100 is in a reclining position, the tenth limiting rod 561 abuts against the seventh link 59. When the mechanical extension structure 100 is in a sitting position and the tenth limiting rod 561 abuts against the secondary footrest 58, the tenth limiting rod 561 restricts the position of the secondary leg rest 58 relative to the main leg rest 55; when the mechanical extension structure 100 is in a reclining position and the tenth limiting rod 561 abuts against the seventh link 59, the tenth limiting rod 561 restricts the position of the seventh link 59 relative to the fifth link 56, so that the fifth link 56 and the seventh link 59 support the secondary leg rest 58.

[0323] In this application, the main leg rest 55 and / or the secondary leg rest 58 are provided with a leg structure (not marked) on which the user's feet can be placed.

[0324] Furthermore, the leg assembly 5 of this application can also be a structure of six links plus a footrest, that is, the leg assembly 5 includes a first link, a second link, a third link, a fourth link, an eighth link, a ninth link and a main legrest. One end of the first link and the second link are respectively rotatably connected to the base, the other end of the first link is rotatably connected to one end of the fourth link, the other end of the second link is rotatably connected to one end of the third link, the middle position of the third link is rotatably connected to the middle position of the first link, the other end of the third link is rotatably connected to one end of the eighth link, the middle position of the eighth link is rotatably connected to the middle position of the fourth link, one end of the ninth link is rotatably connected to the other end of the eighth link, and the other ends of the fourth link and the other ends of the ninth link are respectively rotatably connected to the main legrest.

[0325] As shown in Figure 6, a fourth support rod 7361 is provided on the lower swing plate 736. When the mechanical extension structure 100 is in a seated position, the leg assembly 5 abuts against the fourth support rod 7361. Preferably, the second connecting rod 52 abuts against the fourth support rod 7361. The fourth support rod 7361 is mainly used to limit the position of the leg assembly 5 when the mechanical extension structure 100 is in a seated position.

[0326] As shown in Figure 6, the rear swing plate 731 is also provided with a first hook rod 7311, the axial length of the first hook rod 7311 is greater than the axial length of the fourth limiting rod 7312, and the base 2 is provided with a second hook rod 213, the axial length of the second hook rod 213 is greater than the axial length of the fourth limiting rod 7312. A second elastic element (unmarked) is provided between the first hook rod 7311 and the second hook rod 213. The second elastic element is a second tension spring. At least part of the second elastic element is located outside the fourth limiting rod 7312 to avoid interference between the fourth limiting rod 7312 and the second elastic element during the transformation of the mechanical extension structure 100 between the sitting position and the lying position.

[0327] In this application, the axial length of the second elastic element of the mechanical extension structure 100 when it is in a sitting position is less than the axial length of the second elastic element when it is in a lying position. When the mechanical extension structure 100 is in a sitting position, the fourth limiting rod 7312 abuts against the base 2 and is located in front of the first connecting rod 7311. When the mechanical extension structure 100 is in a lying position, the fourth limiting rod 7312 does not abut against the base 2 and is located above at least part of the first connecting rod 7311.

[0328] Preferably, the first hook rod 7311 is provided with a first hook groove 73111 located outside the fourth limiting rod 7312, the second hook rod 213 is provided with a second hook groove 2131 located outside the fourth limiting rod 7312, one end of the second elastic element is hooked in the first hook groove 73111, and the other end of the second elastic element is hooked in the second hook groove 2131.

[0329] Currently, a large portion of mainstream sofas on the market are developing towards zero wall contact, zero gap, zero gravity, and zero back rubbing. These sofas include a backrest structure, a seat cushion structure, and a mechanical extension structure. The mechanical extension structure has sitting and reclining positions. "Zero wall contact" means that during the transition from a sitting to a reclining position, the backrest structure only moves forward to prevent interference with the wall. "Zero gap" means there is no gap between the backrest and seat cushion structures during the transition. "Zero gravity" means that when the mechanical extension structure is in the reclining position, the user's heart height is almost the same as or lower than the user's leg height. "Zero back rubbing" means that the backrest structure does not pull on the user's clothing during the transition. However, sofas with zero wall contact, zero gap, zero gravity, and zero back rubbing suffer from instability; that is, the sofa is prone to tipping over when the mechanical extension structure is in the reclining position.

[0330] As shown in Figures 1 and 10, the mechanical extension structure 100 includes a first elastic element 594 disposed on the leg assembly 5 and providing tension to the leg assembly 5. When the mechanical extension structure 100 is not in a sitting position, the length of the first elastic element 594 is less than the length of the first elastic element 594 when the mechanical extension structure 100 is in a sitting position, and / or, when the mechanical extension structure 100 is not in a lying position, the length of the first elastic element 594 is less than the length of the first elastic element 594 when the mechanical extension structure 100 is in a lying position.

[0331] As shown in Figures 12 and 13, the included angle between the backrest 41 and the lower end face of the base 1 is e, the length between the backrest 41 and the leg assembly 5 is L1, and the height of the main leg rest 55 is H; after the mechanical extension structure 100 changes from a sitting position to a lying position, the change in e is ≥35°, the change in L1 is ≥380mm, and the change in H is ≥160mm.

[0332] The length of the base 2 is L2, and L2≥560mm; the distance between the center of gravity of the base 2 and the foremost position of the base 1 is L3, and when the mechanical extension structure 100 is in a lying position, L3≤100mm.

[0333] In this application, during the process of the mechanical extension structure 100 changing from a sitting position to a reclining position, the backrest 41 always moves forward to achieve the "zero wall-leaning" function of the sofa.

[0334] In this application, after the mechanical extension structure 100 changes from a sitting position to a reclining position, the change in e is ≥35°, the change in L1 is ≥380mm, and the change in H is ≥160mm. The sofa achieves "zero gap", "zero gravity", and "zero back rubbing" functions by coordinating three parameters: "the change in the included angle between the backrest 41 and the lower end face of the base 1", "the change in the length dimension between the backrest 41 and the main leg rest 55", and "the change in the height dimension of the main leg rest 55".

[0335] Among them, the parameter "change in the angle between the backrest 41 and the lower end face of the base 1" is the most critical. The sofa's "zero gap", "zero gravity", and "zero back rubbing" functions are all affected by this parameter. The parameters "change in the length between the backrest 41 and the main leg panel 55" and "change in the angle between the backrest 41 and the lower end face of the base 1" work together to achieve the sofa's "zero gap" and "zero back rubbing" functions. The parameters "change in the height of the main leg panel 55" and "change in the angle between the backrest 41 and the lower end face of the base 1" work together to achieve the sofa's "zero gravity" function.

[0336] In this application, as shown in Figures 4 and 5, the backrest panel 41 is provided with a mounting position 411 for mounting the backrest structure 200. The mounting position 411 is a mounting hole with a quadrilateral outline. The angle between the center line of the quadrilateral and the lower end face of the base 1 is θ. As shown in Figure 12, the backrest panel 41 is provided with a front side 415 and a rear side 416. When the outline of the mounting hole is circular or other shapes, the angle between the center line of the front side 415 and the rear side 416 and the lower end face of the base 1 is θ.

[0337] In this application, the parameter "length dimension of base 2 ≥ 560mm" is set to increase the contact area between the seat cushion structure 300 and the user's legs, thereby achieving the purpose of a large seat depth, legs not dangling, and the user semi-reclining on the sofa. Based on the change in the length dimension of base 2, the three parameters "change in the included angle between backrest 41 and the lower end face of base 1", "change in the length dimension between backrest 41 and main leg rest 55", and "change in the height dimension of main leg rest 55" are all adjusted.

[0338] In related technologies, during the transition from a sitting to a reclining position via the mechanical extension structure, the backrest of a "zero-wall" sofa continuously moves forward, while the base moves forward along with it. Because the base moves forward with the backrest, when the mechanical extension structure is in the reclining position, the main leg rest of the "zero-wall" sofa is higher and farther from the base compared to the main leg rest of a "non-zero-wall" sofa, causing the sofa's center of gravity to shift away from the base. When the mechanical extension structure is in the reclining position and the user is lying on the "zero-wall" sofa, the sofa is prone to tipping over at the main leg rest.

[0339] As shown in Figure 13, in order to accommodate the change in the length of the base 2, the distance L3 between the center of gravity of the base 2 and the foremost position of the base 1 is ≤100mm. By reducing the distance between the center of gravity of the base 2 and the foremost position of the base 1, the probability of the "zero-wall" function sofa tipping over can be reduced.

[0340] As shown in Figures 1 and 2, the mechanical extension structure 100 includes a first elastic element 594 disposed on the leg assembly 5. When the mechanical extension structure 100 is not in a sitting position, the length of the first elastic element 594 is less than the length of the first elastic element 594 when the mechanical extension structure 100 is in a sitting position. Therefore, the tension of the first elastic element 594 when the mechanical extension structure 100 is not in a sitting position is less than the tension of the first elastic element 594 when the mechanical extension structure 100 is in a sitting position, so that the first elastic element 594 provides tension to the leg assembly 5. The beneficial effects of "the tension of the first elastic element 594 when the mechanical extension structure 100 is not in a sitting position is less than the tension of the first elastic element 594 when the mechanical extension structure 100 is in a sitting position" are: 1. During the process of the mechanical extension structure 100 changing from a sitting position to a lying position, the initial driving force required by the first drive mechanism 6 will be reduced with the assistance of the tension of the first elastic element 594. The initial driving force required by the first drive mechanism 6 will be appropriately reduced, meaning that even if the length of the base 2 increases to 560mm or more, the specifications of the first drive mechanism 6 (which mainly refers to the power of the first drive mechanism 6, but can also be understood as horsepower, speed, efficiency, power factor, etc.) will not need to be increased with the assistance of the first elastic element 594. Especially when the first drive mechanism 6 is already a standard drive mechanism with the largest specifications on the market, not needing to increase the specifications of the first drive mechanism means that there is no need to customize a special specification first drive mechanism 6 for a single sofa. 2. During the process of the mechanical extension structure 100 changing from a sitting position to a reclining position, the initial driving force required by the first drive mechanism 6 will be appropriately reduced with the assistance of the tension of the first elastic element 594. After the initial driving force required by the first drive mechanism 6 is appropriately reduced, the motion stability of the mechanical extension structure 100 will be improved.

[0341] Similarly, in this application, the mechanical extension structure 100 includes a first elastic element 594 disposed on the leg assembly 5. When the mechanical extension structure 100 is not in a lying position, the length of the first elastic element 594 is less than the length of the first elastic element 594 when the mechanical extension structure 100 is in a lying position. Therefore, the tension of the first elastic element 594 when the mechanical extension structure 100 is not in a lying position is less than the tension of the first elastic element 594 when the mechanical extension structure 100 is in a lying position, so as to realize that the first elastic element 594 provides tension for the leg assembly 5. The beneficial effects of "the tension of the first elastic element 594 when the mechanical extension structure 100 is not in a lying position is less than the tension of the first elastic element 594 when the mechanical extension structure 100 is in a lying position" are: 1. During the process of the mechanical extension structure 100 changing from a lying position to a sitting position, the first drive motor The initial driving force required by the first drive mechanism 6 will be appropriately reduced with the assistance of the tension of the first elastic element 594; that is, even if the length of the base 2 of this application increases to 560mm or more, the specifications of the first drive mechanism 6 do not need to be increased with the assistance of the first elastic element 594; especially when the first drive mechanism 6 has already selected the largest standard drive mechanism on the market, not needing to increase the specifications of the first drive mechanism 6 means that there is no need to customize a special specification first drive mechanism 6 for a single sofa. 2. During the process of the mechanical extension structure 100 changing from a reclining position to a sitting position, the initial driving force required by the first drive mechanism 6 will be appropriately reduced with the assistance of the tension of the first elastic element 594. After the initial driving force required by the first drive mechanism 6 is appropriately reduced, the motion stability of the mechanical extension structure 100 will be improved.

[0342] As shown in Figures 1, 2, and 3, the mechanical extension structure 100 also has a TV position. When the mechanical extension structure 100 is in the TV position, the length of the first elastic element 594 is less than the length of the first elastic element 594 when the mechanical extension structure 100 is in the sitting position, and / or, the length of the first elastic element 594 when the mechanical extension structure 100 is in the TV position is less than the length of the first elastic element 594 when the mechanical extension structure 100 is in the lying position.

[0343] Since the first elastic element 594 provides tension to the leg assembly 5, the length of the first elastic element 594 when the mechanical extension structure 100 is in the TV position is less than the length of the first elastic element 594 when the mechanical extension structure 100 is in the sitting position, and the tension of the first elastic element 594 when the mechanical extension structure 100 is in the TV position is less than the tension of the first elastic element 594 when the mechanical extension structure 100 is in the sitting position.

[0344] Similarly, since the first elastic element 594 provides tension to the leg assembly 5, the length of the first elastic element 594 when the mechanical extension structure 100 is in the TV position is less than the length of the first elastic element 594 when the mechanical extension structure 100 is in the lying position, and the tension of the first elastic element 594 when the mechanical extension structure 100 is in the TV position is less than the tension of the first elastic element 594 when the mechanical extension structure 100 is in the lying position.

[0345] As shown in Figure 2, a first support rod 812 is provided on one of the first support plate 81 and the second support plate 82. When the mechanical extension structure 100 is in the TV position, when the mechanical extension structure 100 is in the lying position, and during the process of the mechanical extension structure 100 changing from the TV position to the lying position, the lower end face of the roller 811 is not higher than the lower end face of the base 1, and the first support rod 812 abuts against the other of the first support plate 81 and the second support plate 82. When the mechanical extension structure 100 is in the lying position, the center of gravity of the base 2 is located in front of the base 1.

[0346] In this application, preferably, one end of the first support plate 81 is rotatably connected to the front support plate 71.

[0347] Because the center of gravity of the base 2 is located in front of the base 1, the sofa is prone to tipping over at the main leg rest 55 when the mechanical extension structure 100 is in a reclining position and the user is lying on the sofa. In this application, when the mechanical extension structure 100 is in a reclining position, the lower end face of the roller 811 is not higher than the lower end face of the base 1 to ensure that the roller 811 contacts the ground. The first support rod 812 abuts against the first support plate 81 and the other of the second support plate 82 to prevent the first support plate 81 from moving relative to the second support plate 82. That is, by having the roller 811 contact the ground and by preventing the first support plate 81 from moving relative to the second support plate 82, the roller 811 provides support to the base 2 sequentially via the first support plate 81 and the swing mechanism 7. This structure effectively prevents the sofa from tipping over when the mechanical extension structure 100 is in a reclining position.

[0348] As shown in Figure 2, when the mechanical extension structure 100 is in the TV position, and during the process of changing the mechanical extension structure 100 from the TV position to the reclining position, the lower end surface of the roller 811 is not higher than the lower end surface of the base 1, and the first support rod 812 abuts against the other of the first support plate 81 and the second support plate 82. This structure is used to prevent the sofa from tipping over at the main leg rest 55 when the mechanical extension structure 100 is in the TV position, and from tipping over at the main leg rest 55 during the process of changing the mechanical extension structure 100 from the TV position to the reclining position.

[0349] As shown in Figures 2, 12, and 13, when the mechanical extension structure 100 is in a seated position, the angle between the center line of the backrest 41 and the lower end face of the base 1 is ≤65°, and the minimum distance between the upper end face of the main leg rest 55 and the lower end face of the base 1 is ≤30mm; when the mechanical extension structure 100 is in a reclining position, the angle between the center line of the backrest 41 and the lower end face of the base 1 is ≤20°, and the minimum distance between the upper end face of the main leg rest 55 and the lower end face of the base 1 is ≥450mm.

[0350] In this application, "during the transition from a sitting to a reclining position, the main leg rest 55 is raised to a height exceeding 420mm," and "when the mechanical extension structure 100 is in the reclining position, the angle between the center line of the backrest 41 and the lower end face of the base 1 is ≤20°," thereby achieving the "zero gravity" function of the sofa by increasing the raising height of the main leg rest 55 and the reclining range of the backrest 41. However, "during the transition from a sitting to a reclining position, the main leg rest 55 is raised to a height exceeding 420mm," and "when the mechanical extension structure 100 is in the reclining position, the angle between the center line of the backrest 41 and the lower end face of the base 1 is ≤20°," also make the sofa prone to tipping over at the main leg rest 55. Therefore, when the mechanical extension structure 100 is in the reclining position, the first support plate 81, the second support plate 82, and the casters 811 are required for auxiliary support.

[0351] When using the second, third, and fourth swing mechanisms 7, the included angle e and height H can also be optimized: when the mechanical extension structure 100 is in a sitting position, the included angle between the center line of the backrest 41 and the lower end face of the base 1 is ≥70°, and the minimum distance between the upper end face of the main leg rest 55 and the lower end face of the base 1 is ≤30mm; when the mechanical extension structure 100 is in a reclining position, the included angle between the center line of the backrest 41 and the lower end face of the base 1 is ≥30°, and the minimum distance between the upper end face of the main leg rest 55 and the lower end face of the base 1 is ≤430mm.

[0352] In this application, "during the transition from a sitting to a reclining position, the lifting height of the main leg rest 55 is less than 400mm" and "when the mechanical extension structure 100 is in the reclining position, the angle between the center line of the backrest 41 and the lower end face of the base 1 is ≥30°" reduces the lifting height of the main leg rest 55 and the reclining range of the backrest 41, thereby achieving the "zero gravity" function of the sofa. However, "during the transition from a sitting to a reclining position, the lifting height of the main leg rest 55 is less than 400mm" and "when the mechanical extension structure 100 is in the reclining position, the angle between the center line of the backrest 41 and the lower end face of the base 1 is ≥30°" reduces the probability of the sofa tipping over at the main leg rest 55. Therefore, when the mechanical extension structure 100 is in the reclining position, the first support plate 81, the second support plate 82, and the casters 811 can be eliminated.

[0353] As shown in Figure 3, the leg assembly 5 includes a first link 51, a second link 52, a third link 53, and an auxiliary rod 591. One end of the first link 51 is rotatably connected to the auxiliary rod 591, the first link 51 is rotatably connected to the third link 53, and the position of the first link 51 off-end is also rotatably connected to the base 2. One end of the second link 52 is rotatably connected to the base 2, and the other end of the second link 52 is rotatably connected to one end of the third link 53.

[0354] One end of the first elastic element 594 is located on the auxiliary rod 591, and the other end of the first elastic element 594 is located on the base 1. When the mechanical extension structure 100 is in a seated position, the angle between the auxiliary rod 591 and the first connecting rod 51 is c, where c < 90°; when the mechanical extension structure 100 is in a TV position, c > 90°.

[0355] In this application, the connection position between the first link 51 and the base 2 has been changed: in the related technology, the first link is rotatably connected to the base through its end. However, in this application, the first link 51 is rotatably connected to the base 2 through a position offset from its end. During the process of the mechanical extension structure 100 changing from a seated position to a TV position, the distance between the "rotatable connection between the first link 51 and the base 2" and the "position on the first link 51 for connecting the auxiliary rod 591" is used to control the amount of change in the length of the first elastic element 594.

[0356] In this application, the auxiliary rod 591, which is rotatably connected to one end of the first connecting rod 51, has the following beneficial effects: 1. During the rotation of the first connecting rod 51 relative to the base 2, the first connecting rod 51 (the position of the first connecting rod 51 offset from the end and rotatably connected to the base 2) will drive the auxiliary rod 591 to move upward; since the auxiliary rod 591 can rotate relative to the first connecting rod 51, during the upward movement of the auxiliary rod 591 driven by the first connecting rod 51, the auxiliary rod 591 reduces its height relative to the base 2 by rotating, thereby reducing the height of the auxiliary rod 591 and the first elastic rod to a certain extent. 1. The probability of interference between element 594 and seat structure 300; 2. The auxiliary rod 591 can adjust the relative position of the first elastic element 594 with respect to the first connecting rod 51 to reduce or even avoid torsional deformation of the first elastic element 594 during movement; 3. When the auxiliary rod 591 and the fourth connecting rod 54 are located at both ends of the first connecting rod 51, and the position of the first connecting rod 51 off-end is rotatably connected to the base 2, the forces applied by the auxiliary rod 591 and the fourth connecting rod 54 to the first connecting rod 51 are in opposite directions to improve the deformation resistance of the first connecting rod 51.

[0357] In this application, since the position of the base 1 does not change, as shown in Figures 1 and 2, during the process of the mechanical extension structure 100 changing from a sitting position to a TV position, the first link 51 rotates counterclockwise relative to the base 2. Then, the first link 51 drives the first elastic element 594 to move towards the backrest assembly 4 via the auxiliary rod 591, thereby shortening the length of the first elastic element 594. As shown in Figures 2 and 3, during the process of the mechanical extension structure 100 changing from a TV position to a reclining position, the base 2 moves away from the base 1. Then, the first link 51 drives the first elastic element 594 to move away from the backrest assembly 4 via the auxiliary rod 591, thereby increasing the length of the first elastic element 594. Similarly, as shown in Figures 2 and 3, during the process of the mechanical extension structure 100 changing from a reclining position to a TV position, the base 2 moves towards the base 1, and then the first link 51 drives the first elastic element 594 to move towards the backrest assembly 4 via the auxiliary rod 591, thereby reducing the length of the first elastic element 594; as shown in Figures 1 and 2, during the process of the mechanical extension structure 100 changing from a TV position to a sitting position, the first link 51 rotates clockwise relative to the base 2, and then the first link 51 drives the first elastic element 594 to move away from the backrest assembly 4 via the auxiliary rod 591, thereby increasing the length of the first elastic element 594.

[0358] Preferably, the first elastic element 594 is a tension spring, and the tension spring is a first tension spring. One end of the first connecting rod 51 is provided with at least two first hook parts (not marked) for rotatably connecting with the auxiliary rod 591. The first hook parts extend from the first connecting rod 51 in a direction away from the base 2.

[0359] In this application, the fact that "the first connecting part extends from the first connecting rod 51 in a direction away from the base 2" can effectively prevent the first tension spring from interfering with the base 2 or the swing mechanism 7 during the rotation of the first connecting rod 51 relative to the base 2. In addition, the first connecting part at different positions is adapted to first tension springs of different lengths and diameters.

[0360] As shown in Figure 2, the leg assembly 5 also includes a fourth link 54. The other end of the third link 53 is rotatably connected to the main leg rest 55. The other end of the first link 51 is rotatably connected to one end of the fourth link 54. The other end of the fourth link 54 is rotatably connected to the main leg rest 55. A second support rod 531 is provided on the third link 53. When the mechanical extension structure 100 is in the TV position and when the mechanical extension structure 100 is in the lying position, the second support rod 531 abuts against the first link 51.

[0361] In this application, besides being disposed on the base 1, the other end of the first elastic element 594 can also be disposed on other components of the mechanical extension structure 100: the leg assembly 5 includes a first connecting rod 51, a second connecting rod 52, a third connecting rod 53, and an auxiliary rod 591. One end of the first connecting rod 51 is rotatably connected to the auxiliary rod 591, the first connecting rod 51 is rotatably connected to the third connecting rod 53, and the position of the first connecting rod 51 off-end is also rotatably connected to the base 2. One end of the second connecting rod 52 is rotatably connected to the base 2. The second link 52 is rotatably connected to one end of the third link 53. One end of the first elastic element 594 is located on the auxiliary rod 591, and the other end of the first elastic element 594 is located on one of the base 2, the swing mechanism 7, and the backrest assembly 4. When the mechanical extension structure 100 is in a seated position, the angle between the auxiliary rod 591 and the first link 51 is <90°; when the mechanical extension structure 100 is in a TV position, the angle between the auxiliary rod 591 and the first link 51 is >90°. During the transition of the mechanical extension structure 100 from a seated position to a TV position, the first link 51 rotates counterclockwise relative to the base 2, thereby driving the auxiliary rod 591 to move relative to the base 1, thereby shortening the length of the first elastic element 594. However, during the transition of the mechanical extension structure 100 from a TV position to a reclining position, since the base 2, the swing mechanism 7, and the backrest assembly 4 cannot move relative to the first link 51 (or the base 2, the swing mechanism 7, and the backrest assembly 4 move a small distance relative to the first link 51), when the other end of the first elastic element 594 is located in one of the base 2, the swing mechanism 7, and the backrest assembly 4, the first elastic element 594 cannot increase its length (or increases its length by a small distance). In other words, during the transition between the TV position and the reclining position, the tension of the first elastic element 594 on the base 1 is greater than the tension of the first elastic element 594 on the base 2, the swing mechanism 7, and the backrest assembly 4. In this case, the mechanical extension structure 100 usually needs to be equipped with another tension spring to increase the tension of the mechanical extension structure 100 during the transition between the TV position and the reclining position.

[0362] As shown in Figures 4 and 5, a third limiting rod 30 is provided on the front support 42 of the backrest. When the mechanical extension structure 100 is in a sitting position, the third limiting rod 30 abuts against the backrest panel 41 at a first position; when the mechanical extension structure 100 is in a reclining position, the third limiting rod 30 abuts against the backrest panel 41 at a second position. The backrest panel 41 abuts against the third limiting rod 30 at the first and second positions respectively. That is to say, during the process of the mechanical extension structure 100 changing between the sitting and reclining positions, the third limiting rod 30 changes position relative to the backrest panel 41, preventing the third limiting rod 30 from not abutting against the backrest panel 41 during the process of the mechanical extension structure 100 changing between the sitting and reclining positions, thereby preventing the third limiting rod 30 from preventing the backrest panel 41 from moving relative to the base 2. When the mechanical extension structure 100 is in a sitting position and when the mechanical extension structure 100 is in a reclining position, the third limiting rod 30 abuts against the backrest 41 so that the front support 42 of the backrest provides support to the backrest 41 through the third limiting rod 30.

[0363] In this application, the backrest panel 41 is located inside the base 2, and an anti-pinch plate (not marked) is provided on the outer side of the backrest panel 41. Parts of the front backrest bracket 42 and the rear backrest bracket 43 correspond to the anti-pinch plate. When parts of the front backrest bracket 42 and the rear backrest bracket 43 correspond to the anti-pinch plate, the anti-pinch plate covers them. This structure prevents the front backrest bracket 42 from pinching the user during rotation relative to the backrest panel 41, and also prevents the rear backrest bracket 43 from pinching the user during rotation relative to the backrest panel 41. Furthermore, the anti-pinch plate is located within the projection of the backrest structure 200 onto the horizontal plane, and is also located inside the seat cushion structure 300. That is, the backrest structure 200 and the seat cushion structure 300 cooperate to prevent the backrest assembly 4 from pinching the user. Normally, the base 2 is located inside the seat cushion structure 300.

[0364] In related technologies, invention patent application number 2024118229413 discloses a seat extension device and a seat. The seat includes a mechanical extension structure, which includes a rear swing plate, a base plate, and a tension spring. A limiting rod is provided on the rear swing plate, and one end of the tension spring is hung on the base plate, while the other end of the tension spring is hung on the limiting rod. The mechanical extension structure has a sitting position and a reclining position. When the mechanical extension structure is in the sitting position and the limiting rod abuts against the base plate, the tension spring is prone to interference with the base plate. This leads to: 1. The mechanical extension structure is prone to noise; due to the interference between the tension spring and the base plate, the tension spring is prone to noise during the process of the base plate compressing the tension spring. 2. The mechanical extension structure is prone to instability when in the sitting position; when the mechanical extension structure is in the sitting position and the tension spring abuts against the base plate, the limiting rod does not abut against the base plate, which causes instability in the mechanical extension structure.

[0365] In this application, the second elastic element is a second tension spring. When the mechanical extension structure 100 is in a seated position, the fourth limiting rod 7312 abuts against the base plate 2. The fourth limiting rod 7312 is located in front of the first hanging rod 7311. Since the fourth limiting rod 7312 is located in front of the first hanging rod 7311 and one end of the second elastic element is hung on the first hanging rod 7311, when the mechanical extension structure 100 is in a seated position, the probability of interference between the second elastic element and the base 2 is reduced by moving the position of the first hanging rod 7311 on the rear swing plate 731. Since the length of the first connecting rod 7311 is greater than the length of the fourth limiting rod 7312, the probability of interference between the second elastic element and the fourth limiting rod 7312 is effectively reduced when the mechanical extension structure 100 is in a seated position and the fourth limiting rod 7312 is in front of the first connecting rod 7311, and when the mechanical extension structure 100 is in a reclining position and the fourth limiting rod 7312 is above the first connecting rod 7311. In other words, the conditions that "the fourth limiting rod 7312 is in front of the first connecting rod 7311," "the fourth limiting rod 7312 is above the first connecting rod 7311," and "the length of the first connecting rod 7311 is greater than the length of the fourth limiting rod 7312" effectively solve the problem of noise generated by the mechanical extension structure 100 during movement and also solve the problem of instability when the mechanical extension structure 100 is in a seated position.

[0366] Since the length of the second elastic element of the mechanical extension structure 100 in the sitting position is less than that in the lying position, the second elastic element provides a preload when the mechanical extension structure 100 is in the sitting position. The most direct manifestation of the preload of the second elastic element is to change the force required for the base 2 to move relative to the rear swing plate 731. The preload of the second elastic element indirectly affects the sequence of movement of the leg assembly 5 relative to the base 2.

[0367] As shown in Figure 14, the leg assembly 5 includes a first connecting rod 51, a second connecting rod 52, a third connecting rod 53, a first auxiliary rod 592, and a second auxiliary rod 593. The second auxiliary rod 593 is rotatably connected to one end of the first auxiliary rod 592 and is rotatably connected to the swing mechanism 7. One end of the second connecting rod 52 is rotatably connected to the other end of the first auxiliary rod 592. The first connecting rod 51 is rotatably connected to the third connecting rod 53. One end of the first connecting rod 51 is rotatably connected to the base 2, and the other end of the second connecting rod 52 is rotatably connected to one end of the third connecting rod 53. The second connecting rod 52 is also rotatably connected to the base 2.

[0368] The first elastic element 594 is located at one end of the second auxiliary rod 593. The second auxiliary rod 593 is used to position the first elastic element 594 below the first auxiliary rod 592. The other end of the first elastic element 594 is located on the base 1. When the mechanical extension structure 100 is in a seated position, the angle between the second auxiliary rod 593 and the second connecting rod 52 is <90°. When the mechanical extension structure 100 is in a TV position, the angle between the second auxiliary rod 593 and the second connecting rod 52 is >90°.

[0369] In this application, the second auxiliary rod 593, which is rotatably connected to the swing mechanism 7, has the following beneficial effects: 1. During the rotation of the second connecting rod 52 relative to the base 2, the second connecting rod 52 will drive the first auxiliary rod 592 to move, and the first auxiliary rod 592 will drive the second auxiliary rod 593 to rotate relative to the swing mechanism 7; since the position of the second auxiliary rod 593 for setting the first elastic element 594 is located below the first auxiliary rod 592, during the movement of the first auxiliary rod 592 driven by the second connecting rod 52, the first auxiliary rod 592 can, to a certain extent, prevent the second auxiliary rod 593, the first elastic element 594 and the seat structure 300 from interfering with each other by lowering the height position of the second auxiliary rod 593; 2. The second auxiliary rod 593 can adjust the relative position of the first elastic element 594 relative to the second connecting rod 52, so as to reduce or even avoid the torsional deformation of the first elastic element 594 during the movement of the second connecting rod 52.

[0370] In this application, since the position of the base 1 does not change, during the process of the mechanical extension structure 100 changing from a sitting position to a TV position, the second link 52 rotates counterclockwise relative to the base 2. Then, the second link 52 drives the first elastic element 594 to move towards the backrest assembly 4 via the first auxiliary rod 592 and the second auxiliary rod 593 in sequence, so as to shorten the length of the first elastic element 594. During the process of the mechanical extension structure 100 changing from a TV position to a reclining position, the base 2 moves away from the base 1. Then, the second link 52 drives the first elastic element 594 to move away from the backrest assembly 4 via the first auxiliary rod 592 and the second auxiliary rod 593 in sequence, so as to increase the length of the first elastic element 594. Similarly, during the transition of the mechanical extension structure 100 from a reclining position to a TV position, the base 2 moves towards the base 1, and the second link 52 sequentially drives the first elastic element 594 towards the backrest assembly 4 via the first auxiliary rod 592 and the second auxiliary rod 593, thereby reducing the length of the first elastic element 594. During the transition of the mechanical extension structure 100 from a TV position to a sitting position, the second link 52 rotates clockwise relative to the base 2, and the second link 52 sequentially drives the first elastic element 594 towards the backrest assembly 4 via the first auxiliary rod 592 and the second auxiliary rod 593, thereby increasing the length of the first elastic element 594.

[0371] As shown in Figure 14, the second auxiliary rod 593 is rotatably connected to the swing mechanism 7 at a position offset from its lower end, and one end of the first elastic element 594 is hung on the lower end of the second auxiliary rod 593. When the first elastic element 594 and the first auxiliary rod 592 are located at both ends of the second auxiliary rod 593, and the second auxiliary rod 593 is rotatably connected to the swing mechanism 7 at a position offset from its end, the forces exerted by the first elastic element 594 and the first auxiliary rod 592 on the second auxiliary rod 593 are in opposite directions, thereby improving the deformation resistance of the second auxiliary rod 593.

[0372] In this application, preferably, the upper end of the second auxiliary rod 593 is rotatably connected to one end of the first auxiliary rod 592, and the position of the second auxiliary rod 593 offset from its upper end is rotatably connected to the base 2; or, the upper end of the second auxiliary rod 593 and one end of the first auxiliary rod 592 are respectively rotatably connected to the base 2. The "position of the second auxiliary rod 593 offset from its upper end and rotatably connected to the base 2" and the "position of the upper end of the second auxiliary rod 593 rotatably connected to the base 2" can constrain the range of motion of the second auxiliary rod 593.

[0373] In this application, the swing mechanism 7 can be the first type of swing mechanism 7 shown in Figures 1, 2 and 3. Other swing mechanisms 7 can also be used, for example:

[0374] The second type of swing mechanism 7 includes a main connecting rod 31, a secondary connecting rod 32, an intermediate connecting rod 33, a front main swing rod 34, a front secondary swing rod 35, a rear main swing rod 36, a rear secondary swing rod 37, and a rear support rod 38. One end of the rear support rod 38 is rotatably connected to the base 2. The second auxiliary rod 593 is offset from its lower end, and the other end of the rear support rod 38 is rotatably connected to the intermediate connecting rod 33. The other ends of the front main swing rod 34 and the rear main swing rod 36 are rotatably connected to the base 1. The front secondary swing rod... The other end of rod 35 and the other end of rear auxiliary swing rod 37 are respectively rotatably connected to intermediate connecting rod 33. One end of front auxiliary swing rod 35 is rotatably connected to front main swing rod 34. One end of rear auxiliary swing rod 37 is rotatably connected to rear main swing rod 36. One end of main connecting rod 31 is rotatably connected to one end of front main swing rod 34. The other end of main connecting rod 31 is rotatably connected to rear main swing rod 36. One end of auxiliary connecting rod 32 is rotatably connected to main connecting rod 31. The other end of auxiliary connecting rod 32 is rotatably connected to rear auxiliary swing rod 37.

[0375] The third type of swing mechanism 7 includes a main connecting rod 31, a secondary connecting rod 32, an intermediate connecting rod 33, a front main swing rod 34, a front secondary swing rod 35, a rear main swing rod 36, a rear secondary swing rod 37, and a rear support rod 38. One end of the rear support rod 38 is rotatably connected to the base 2. The second auxiliary rod 593 is offset from its lower end, and the other end of the rear support rod 38 is rotatably connected to the intermediate connecting rod 33. The other ends of the front main swing rod 34 and the rear main swing rod 36 are rotatably connected to the base 1. The front secondary swing rod... The other end of rod 35 and the other end of rear auxiliary swing rod 37 are respectively rotatably connected to intermediate connecting rod 33. One end of front auxiliary swing rod 35 is rotatably connected to front main swing rod 34. One end of rear auxiliary swing rod 37 is rotatably connected to rear main swing rod 36. One end of main connecting rod 31 is rotatably connected to front main swing rod 34. The other end of main connecting rod 31 is rotatably connected to rear auxiliary swing rod 37. One end of auxiliary connecting rod 32 is rotatably connected to main connecting rod 31. The other end of auxiliary connecting rod 32 is rotatably connected to rear main swing rod 36.

[0376] As shown in Figure 14, the fourth type of swing mechanism 7 includes a main connecting rod 31, a secondary connecting rod 32, an intermediate connecting rod 33, a front main swing rod 34, a front secondary swing rod 35, a rear main swing rod 36, a rear secondary swing rod 37, and a rear support rod 38. One end of the rear support rod 38 is rotatably connected to the base 2. The second auxiliary rod 593 is offset from its lower end, and the other end of the rear support rod 38 is rotatably connected to the intermediate connecting rod 33. The other ends of the front main swing rod 34 and the rear main swing rod 36 are rotatably connected to the base 1. The other ends of the front auxiliary swing arm 35 and the rear auxiliary swing arm 37 are respectively rotatably connected to the intermediate connecting rod 33. One end of the front auxiliary swing arm 35 is rotatably connected to the front main swing arm 34. One end of the rear auxiliary swing arm 37 is rotatably connected to the rear main swing arm 36. The other end of the main connecting rod 31 is rotatably connected to the rear auxiliary swing arm 37. One end of the main connecting rod 31 is rotatably connected to the end of the front main swing arm 34. The other end of the auxiliary connecting rod 32 is rotatably connected to the main connecting rod 31. One end of the auxiliary connecting rod 32 is rotatably connected to the front auxiliary swing arm 35.

[0377] As shown in Figure 14, position A is the rotatable connection between the second auxiliary rod 593 and one end of the first auxiliary rod 592, position B is the rotatable connection between the second auxiliary rod 593 and the swing mechanism 7, and position C is the location where the first elastic element 594 is set on the second auxiliary rod 593. The interval between A and B is greater than the interval between B and C.

[0378] In this application, when the distance between A and B is greater than the distance between B and C, the second auxiliary rod 593 can amplify the force transmitted from the leg assembly 5 to the second auxiliary rod 593 via the first auxiliary rod 592. After the second auxiliary rod 593 amplifies the force transmitted from the leg assembly 5 to the second auxiliary rod 593 via the first auxiliary rod 592, the tension value of the first elastic element 594 can also be appropriately increased. Due to the increased tension value of the first elastic element 594, the initial force required by the first drive mechanism 6 can be further reduced and the working stability of the mechanical extension structure 100 can be further improved during the process of changing the mechanical extension structure 100 from a sitting position to a lying position.

[0379] Preferably, the first elastic element 594 is a tension spring, and the lower end of the second auxiliary rod 593 is provided with at least two second attachment points (not marked) for attaching the tension spring. The second attachment points extend from the second auxiliary rod 593 in a direction away from the base 2. The fact that "the second attachment points extend from the second auxiliary rod 593 in a direction away from the base 2" effectively prevents interference between the first tension spring and the swing mechanism 7 or the second auxiliary rod 593 during the rotation of the second auxiliary rod 593 relative to the swing mechanism 7. Furthermore, the second attachment points at different positions are adapted to first tension springs of different lengths and diameters.

[0380] In this application, preferably, a transmission rod (unmarked) is provided between the two leg components 5, and the transmission rod is provided with a first protrusion (unmarked) and a second protrusion (unmarked), and the first protrusion and the second protrusion are respectively movably connected to the telescopic component 66;

[0381] The transmission rod is provided with a reinforcing rib (unmarked) between the first protrusion and the second protrusion.

[0382] In related technologies, the drive mechanism provides thrust to the first protrusion and the second protrusion respectively, which drives the transmission rod to rotate, so that the transmission rod drives the leg assembly to extend in front of the base or retract to below the base. However, there is a certain probability that the "thrust provided by the drive mechanism to the first protrusion" is different from the "thrust provided by the drive mechanism to the second protrusion", which will cause the synchronization rod located between the first protrusion and the second protrusion to undergo torsional deformation.

[0383] In this application, to increase the deformation resistance of the transmission rod located between the first protrusion and the second protrusion, a reinforcing rib is provided between the first protrusion and the second protrusion on the transmission rod.

[0384] As shown in Figures 1 and 6, the seat unit includes the mechanical extension structure 100 described in any of the above technical solutions. The first drive mechanism 6 includes a motor 61, a first slide rail 62, a lead screw, a slider 63, and a drive rod 64. One end of the drive rod 64 is rotatably connected to the linkage rod 3, and the other end of the drive rod 64 is rotatably connected to the slider 63. The motor 61 and the lead screw are located on the first slide rail 62, with the lead screw located inside the first slide rail. The motor 61 has a motor shaft, and the motor shaft and the lead screw are connected through a transmission mechanism. The transmission mechanism typically includes a driving gear on the motor shaft and a driven gear on the lead screw. The driving gear and the driven gear mesh. The slider 63 is threadedly connected to the lead screw. During the operation of the motor 61, the motor shaft drives the slider 63 to slide along the first slide rail 62 in the axial direction of the lead screw via the driving gear, the driven gear, and the lead screw in sequence, so that the slider 63 drives the linkage rod 3 to rotate and / or move via the drive rod 64. This is related technology. As shown in Figure 6, in this related technology, the motor 61 is located on one side of the first slide rail 62. When the motor 61 is located on one side of the first slide rail 62, the center of gravity of the motor 61 and the center of gravity of the lead screw are not on the same straight line. This will cause the first drive mechanism 6 to be easily damaged, especially the wear degree of different teeth on the driven gear is inconsistent.

[0385] This application improves the first drive mechanism 6, primarily by aligning the centerline of the motor shaft 611 with the centerline of the telescopic assembly 66. Several specific solutions are provided for this improvement of the first drive mechanism 6:

[0386] In the first embodiment, the seat unit includes the mechanical extension structure 100 described in this embodiment, as shown in Figures 8 and 9. The first drive mechanism 6 includes a motor 61 and a telescopic component 66. The motor 61 has a motor shaft 611, which is connected to the telescopic component 66 via a transmission mechanism 65. The motor 61 is located on the base 1. The telescopic component 66 is also movably connected to one of the linkage rod 3 and the leg assembly 5. In the first embodiment, the motor 61 is movably located on the base 1, and the centerline of the motor shaft 611 coincides with the centerline of the telescopic component 66. The telescopic component 66 includes an outer rod 662 and an inner rod 661 located inside the outer rod 662. The outer rod 662 and the inner rod 661 are threaded together, and the motor shaft 611 is connected to the inner rod 661 via the transmission mechanism 65. During the operation of the motor 61, the rotational speed of the motor shaft 611 is different from the rotational speed of the inner rod 661. In the first embodiment, preferably, the leg assembly 5 includes a transmission rod (not marked), an outer rod 662 rotatably connected to the transmission rod, and the transmission rod rotatably connected to the base 2; and / or, the motor 61 includes a body 612, on which a protective cover 613 is provided, the protective cover 613 being fitted onto the outer rod 662, and when the mechanical extension structure 100 is in a sitting position, the transmission rod is exposed outside the protective cover 613; when the mechanical extension structure 100 is in a lying position, the inner rod 661 is not exposed outside the protective cover 613.

[0387] In the second embodiment, the seat unit includes the mechanical extension structure 100 described in this embodiment, as shown in Figures 8 and 9. The first drive mechanism 6 includes a motor 61 and a telescopic component 66. The motor 61 has a motor shaft 611, which is connected to the telescopic component 66 via a transmission mechanism 65. The motor 61 is located on the base 2, and the telescopic component 66 is also movably connected to one of the linkage rod 3 and the leg assembly 5. In the first embodiment, the motor 61 is movably located on the base 2, and the centerline of the motor shaft 611 coincides with the centerline of the telescopic component 66. The telescopic component 66 includes an outer rod 662 and an inner rod 661 located inside the outer rod 662. The outer rod 662 and the inner rod 661 are threaded together, and the motor shaft 611 is connected to the inner rod 661 via a transmission mechanism 65. During the operation of the motor 61, the rotational speed of the motor shaft 611 is different from the rotational speed of the inner rod 661. In the second embodiment, preferably, the leg assembly 5 includes a transmission rod, an outer rod 662 is rotatably connected to the transmission rod, and the transmission rod is rotatably connected to the base 2; and / or, the motor 61 includes a body 612, a protective cover 613 is provided on the body 612, the protective cover 613 is sleeved on the outer rod 662, when the mechanical extension structure 100 is in a sitting position, the transmission rod is exposed outside the protective cover 613; when the mechanical extension structure 100 is in a lying position, the inner rod 661 is not exposed outside the protective cover 613.

[0388] In the third embodiment, the seat unit includes the mechanical extension structure 100 described in this embodiment, as shown in Figures 8 and 9. The first drive mechanism 6 includes a motor 61 and a telescopic component 66. The motor 61 has a motor shaft 611, which is connected to the telescopic component 66 via a transmission mechanism 65. One of the motor 61 and the telescopic component 66 is movably mounted on the leg assembly 5, and the other is movably connected to the swing mechanism 7. In this third embodiment, the centerline of the motor shaft 611 coincides with the centerline of the telescopic component 66. The telescopic component 66 includes an outer rod 662 and an inner rod 661 located inside the outer rod 662. The outer rod 662 and the inner rod 661 are threaded together, and the motor shaft 611 is connected to the inner rod 661 via the transmission mechanism 65. During the operation of the motor 61, the rotational speed of the motor shaft 611 is different from the rotational speed of the inner rod 661. In the third embodiment, preferably, the leg assembly 5 includes a transmission rod, a motor 61 is rotatably connected to the transmission rod, and an outer rod 662 is rotatably connected to the swing mechanism 7; and / or, the motor 61 includes a body 612, a protective cover 613 is provided on the body 612, the protective cover 613 is sleeved on the outer rod 662, when the mechanical extension structure 100 is in a sitting position, the transmission rod is exposed outside the protective cover 613; when the mechanical extension structure 100 is in a lying position, the inner rod 661 is not exposed outside the protective cover 613.

[0389] In the first, second, and third embodiments, the transmission rod is not part of the first drive mechanism 6; that is, the leg assembly 5 includes the transmission rod, or the transmission rod is a connecting structure for connecting the first drive mechanism 6 and the leg assembly 5. In this application, the first connecting rod 51 and / or the second connecting rod 52 on the two leg assemblies 5 are fixedly connected by the transmission rod. When the telescopic assembly 66 is movably connected to the leg assembly 5, the outer rod 662 is connected to the first connecting rod 51 and / or the second connecting rod 52 through the transmission rod, that is, the outer rod 662 is movably connected to the transmission rod, and the transmission rod is fixedly connected to the first connecting rod 51 and / or the second connecting rod 52.

[0390] The beneficial effects of "the centerline of the motor shaft 611 coinciding with the centerline of the telescopic component 66" in the first, second, and third schemes include: 1. increasing the service life of the first drive mechanism 6, especially the transmission mechanism 65, by avoiding the telescopic component 66 being eccentrically mounted on the motor 61; 2. reducing the space required for the first drive mechanism 6 in its radial direction, thereby increasing the range of possible installation positions of the first drive mechanism on the mechanical extension structure 100.

[0391] In the first, second, and third schemes, the transmission mechanism 65 includes a drive gear 651 and three planetary gears 652. The drive gear 651 is located on the motor shaft 611, and the planetary gears 652 are located on the inner rod 661. During the operation of the motor 61, the motor shaft 611 drives the drive gear 651 to rotate, the drive gear 651 drives the planetary gears 652 to rotate, and the planetary gears 652 drive the inner rod 661 to rotate, so as to realize that the inner rod 661 drives the outer rod 662 to move axially relative to the protective cover 613.

[0392] In the first, second, and third schemes, the transmission mechanism 65 is used to adjust the speed of the outer rod 662 relative to the inner rod 611 in the axial direction. That is, the transmission mechanism 65 is used to increase the difference in rotational speed between the motor shaft 611 and the inner rod 661, or to decrease the difference in rotational speed between the motor shaft 611 and the inner rod 661.

[0393] In the first, second, and third schemes, the protective cover 613 is mainly used to prevent the inner rod 661 from being exposed to the outside, thereby preventing external objects from adhering to the inner rod 661. This structure can effectively ensure the reliability of the rotation of the inner rod 661 and the outer rod 662.

[0394] In the first, second, and third schemes, the first drive mechanism 6 is located eccentrically below the seat cushion structure 300. This structure avoids interference between the first drive mechanism 6 and the seat cushion structure 300 during operation, especially with the serpentine spring on the seat cushion structure 300.

[0395] In the first, second, and third schemes, the swing mechanism 7 used in conjunction with the first drive mechanism 6 (the center line of the motor shaft 611 on the first drive mechanism 6 coincides with the center line of the telescopic component 66) can be the swing mechanism shown in Figures 1, 2, and 3. Alternatively, the swing mechanism 7 can be a swing mechanism 7 from related technologies, for example:

[0396] The first related technology's swing mechanism 7 (disclosed in utility model patent application number 2024225864295) includes a main connecting rod, a secondary connecting rod, an intermediate connecting rod, a front main swing rod, a front secondary swing rod, a rear main swing rod, a rear secondary swing rod, a front support rod, and a rear support rod. One end of the front support rod and one end of the rear support rod are rotatably connected to the base, and the other ends of the front support rod and the rear support rod are rotatably connected to the intermediate connecting rod. The other ends of the front main swing rod and the rear main swing rod are rotatably connected to the base, and the other ends of the front secondary swing rod and the rear secondary swing rod are rotatably connected to the intermediate connecting rod. One end of the front secondary swing rod is rotatably connected to the front main swing rod, and one end of the rear secondary swing rod is rotatably connected to the rear main swing rod. One end of the main connecting rod is rotatably connected to one end of the front main swing rod, and the other end of the main connecting rod is rotatably connected to the rear main swing rod. One end of the secondary connecting rod is rotatably connected to the main connecting rod, and the other end of the secondary connecting rod is rotatably connected to the rear secondary swing rod.

[0397] The second related technology's swing mechanism 7 includes a main connecting rod, a secondary connecting rod, an intermediate connecting rod, a front main swing rod, a front secondary swing rod, a rear main swing rod, a rear secondary swing rod, a front support rod, and a rear support rod. One end of the front support rod and one end of the rear support rod are rotatably connected to the base, and the other ends of the front support rod and the rear support rod are rotatably connected to the intermediate connecting rod. The other ends of the front main swing rod and the rear main swing rod are rotatably connected to the base, and the other ends of the front secondary swing rod and the rear secondary swing rod are rotatably connected to the intermediate connecting rod. One end of the front secondary swing rod is rotatably connected to the front main swing rod, and one end of the rear secondary swing rod is rotatably connected to the rear main swing rod. One end of the main connecting rod is rotatably connected to one end of the front main swing rod, and the other end of the main connecting rod is rotatably connected to the rear secondary swing rod. One end of the secondary connecting rod is rotatably connected to the main connecting rod, and the other end of the secondary connecting rod is rotatably connected to the rear main swing rod.

[0398] The third related technology, the swing mechanism 7 (disclosed in utility model patent application number 2024225864295), includes a main connecting rod, a secondary connecting rod, an intermediate connecting rod, a front main swing rod, a front secondary swing rod, a rear main swing rod, a rear secondary swing rod, a front support rod, and a rear support rod. One end of the front support rod and one end of the rear support rod are rotatably connected to the base, and the other ends of the front support rod and the rear support rod are rotatably connected to the intermediate connecting rod. The other ends of the front main swing rod and the rear main swing rod are rotatably connected to the base, and the other ends of the front secondary swing rod and the rear secondary swing rod are rotatably connected to the intermediate connecting rod. One end of the front secondary swing rod is rotatably connected to the front main swing rod, and one end of the rear secondary swing rod is rotatably connected to the rear main swing rod. The other end of the main connecting rod is rotatably connected to the rear secondary swing rod, one end of the main connecting rod is rotatably connected to one end of the front main swing rod, the other end of the secondary connecting rod is rotatably connected to the main connecting rod, and one end of the secondary connecting rod is rotatably connected to the front secondary swing rod.

[0399] The fourth related technology includes a swing mechanism 7 (disclosed in utility model patent application number 2025201747345). The swing mechanism 7 includes a guide and a track. One of the guide and the track is fixedly connected to the base 2, and the other is fixedly connected to the base 1. The guide is inserted into the track. During the process of the mechanical extension structure changing between a sitting position and a lying position, the guide slides along the track.

[0400] In this application, the sofa includes a backrest structure 200 and a seat cushion structure 300, including the seat unit described in this embodiment; wherein, the backrest structure 200 is detachably disposed on the backrest assembly 4, and / or the seat cushion structure 300 is hung on the base 2.

[0401] As shown in Figure 10, the backrest structure 200 is provided with a buckle plate 2001, and the backrest plate 41 is provided with a mounting hole 411. Preferably, the mounting hole 411 is a stepped hole. The buckle plate 2001 is inserted into the mounting hole 411 and abuts against the stepped surface of the stepped hole, so that the backrest structure 200 and the backrest plate 41 are fixedly connected. The distance between the stepped surface and the large-diameter end opening of the stepped hole is <2mm.

[0402] In this application, "the buckle plate 2001 is inserted into the mounting hole 411" means that the buckle plate 2001 is provided with an elastic buckle 20011, and the buckle plate 2001 is inserted into the mounting hole 411 through the elastic buckle 20011.

[0403] As shown in Figures 1 and 10, the backrest panel 41 is provided with a snap-fit ​​groove 414. When the snap-fit ​​plate 2001 is inserted into the mounting hole 411 and abuts against the stepped surface of the stepped hole, the snap-fit ​​plate 2001 is inserted into the snap-fit ​​groove 414. Since the stepped hole reduces the insertion depth of the snap-fit ​​plate 2001 into the mounting hole 411, the snap-fit ​​plate 2001 is fixed to the backrest panel 41 at multiple points by being inserted into the snap-fit ​​groove 414. This structure not only ensures that the snap-fit ​​plate 2001 can be easily removed from the backrest panel 41, but also ensures the connection strength between the snap-fit ​​plate 2001 and the backrest panel 41.

[0404] In related technologies, the backrest panel is provided with mounting holes, which are straight through holes with a depth of ≥2mm. When the depth of the mounting holes is ≥2mm, the backrest panel is more firmly connected to the snap plate on the backrest structure, which makes it difficult to remove the backrest structure during the later maintenance of the sofa.

[0405] In this application, without changing the structure of the backrest panel 41, the existing mounting hole 411 (straight through hole) is replaced with a stepped hole. The distance between the stepped surface of the stepped hole and the large diameter end opening of the stepped hole is <2mm. This structure reduces the difficulty of disassembling the backrest structure 200 while ensuring the connection strength between the backrest panel 41 and the backrest structure 200.

[0406] As shown in Figure 10, the sofa includes a snap-on plate 2001, a first slide rail 2002 on the backrest structure 200, the snap-on plate 2001 can slide along the first slide rail 2002, and a mounting hole 411 on the backrest panel 41. The snap-on plate 2001 is inserted into the mounting hole 411 to fix the backrest structure 200 and the backrest panel 41. An elastic element is provided between the snap-on plate 2001 and the backrest structure 200. The elastic element is a third elastic element 2003. The snap-on plate 2001 moves along the first slide rail 2002 to change the shape of the third elastic element 2003.

[0407] In related technologies, during the process of the mechanical extension structure changing from a sitting position to a reclining position, the backrest structure moves backward relative to the seat cushion structure and compresses the seat cushion structure. During the process of the mechanical extension structure changing from a sitting position to a reclining position, the adjacent components on the swing mechanism (the components on the swing mechanism include the front support plate, the rear support plate, the inner swing assembly, the outer swing assembly, etc.) are not rigidly connected. At this time, the backrest structure compresses the seat cushion structure, and the positional relationship between the adjacent components on the swing mechanism will change. This will cause the swing mechanism to be unable to move along the preset motion trajectory, thereby causing the posture deformation of the mechanical extension structure.

[0408] In this application, a first slide rail 2002 is added to the backrest structure 200. When the backrest structure 200 moves backward relative to the seat cushion structure 300 and presses against the seat cushion structure 300, the first slide rail 2002 drives the backrest structure 200 to move away from the seat cushion structure 300, so as to prevent the swing mechanism 7 from failing to move along the preset motion trajectory. This structure effectively prevents the mechanical extension structure 100 from failing to reach the preset posture position in the sitting position, TV position, and reclining position.

[0409] More preferably, the third elastic element 2003 is a compression spring. During the process of the mechanical extension structure 100 changing from a sitting position to a reclining position, the backrest structure 200 moves backward and upward relative to the seat cushion structure 300, so that the buckle plate 2001 moves relative to the first slide rail 2002 and squeezes the compression spring; during the process of the mechanical extension structure 100 changing from a reclining position to a sitting position, the backrest structure 200 moves forward and downward relative to the seat cushion structure 300, and the compression spring pushes the buckle plate 2001 to move along the first slide rail 2002.

[0410] When the third elastic element 2003 is a compression spring, the compression spring can automatically push the buckle plate 2001 to move along the first slide rail 2002 during the process of the mechanical extension structure 100 changing from a reclining position to a sitting position, so as to realize that the backrest structure 200 automatically returns to the preset position.

[0411] In this application, preferably, the snap-on plate 2001 and the first slide rail 2002 are interference-fitted. This structure increases the difficulty of the backrest structure 200 moving relative to the seat cushion structure 300. That is, the snap-on plate 2001 can only slide relative to the first slide rail 2002 when the backrest structure 200 encounters significant resistance from the seat cushion structure 300.

[0412] In this application, the mechanical extension structure 100 also includes a second slide rail (unmarked) and a slider (unmarked). The slider is provided with a leg structure (unmarked). The second slide rail is disposed on the base, and the slider is slidably disposed on the second slide rail. The slider slides relative to the second slide rail so that the leg structure moves closer to or further away from the seat structure 300.

[0413] In related technologies, a leg assembly is mounted on a base, and the leg assembly has a leg structure for placing the user's feet. The leg assembly includes multiple connecting rods. However, the leg assembly composed of multiple connecting rods has problems such as easy wobbling, the leg assembly not extending to the predetermined distance, and the leg assembly not extending to the predetermined height.

[0414] In this application, since the slider slides along the second slide rail, when the mechanical extension structure 100 also includes the second slide rail and the slider, the distance and height dimensions of the leg structure relative to the seat structure 300 can be accurately controlled.

[0415] Preferably, the second slide rail is fixedly connected to the base 2. When the mechanical extension structure 100 is in a sitting position, the leg structure is located below the seat cushion structure 300. During the process of the mechanical extension structure 100 changing from a sitting position to a lying position, the leg structure moves outward relative to the seat cushion structure 300.

[0416] Alternatively, the second slide rail is movably connected to the base 2. When the mechanical extension structure 100 is in a sitting position, the leg structure is located below the seat cushion structure 300. During the process of the mechanical extension structure 100 changing from a sitting position to a lying position, the leg structure rotates upward relative to the seat cushion structure 300.

[0417] When the second slide rail is fixedly connected to the base 2, the leg structure can extend and retract relative to the seat cushion structure 300. When the second slide rail is fixedly connected to the base 2 and the mechanical extension structure 100 is in a sitting position, the leg structure is located directly below the seat cushion structure 300, that is, the leg structure can be hidden directly below the seat cushion structure 300.

[0418] When the second slide rail is movably connected to the base 2, the leg structure can rotate relative to the seat structure 300. At this time, the leg structure does not need to be hidden in the space directly below the seat structure 300.

[0419] More preferably, when the second slide rail is fixedly connected to the base 2, the second slide rail is located below the leg structure, and the leg structure and the seat cushion structure 300 are connected by the sofa fabric; when the second slide rail is movably connected to the base 2, the second slide rail is located on the side of the leg structure, and the leg structure and the seat cushion structure 300 are integrated. When the mechanical extension structure 100 is not in the sitting position, the "second slide rail being located below the leg structure, and the leg structure and the seat cushion structure 300 being connected by the sofa fabric" is used to prevent the sliding parts from being exposed on the sofa, and to prevent the user from being scratched or pinched by the sliding parts and the second slide rail. The sofa fabric includes genuine leather, cotton linen, technical fabric, velvet, etc. When the mechanical extension structure 100 is not in a seated position, "the second slide rail is located on the side of the leg structure, and the leg structure and the seat cushion structure 300 are integrated" to prevent the sliding parts from being exposed on the sofa, to prevent the user from being scratched or pinched by the sliding parts and the second slide rail, and to ensure that there is filling material at the connection between the leg structure and the seat cushion structure 300. In this application, the leg structure, seat cushion structure 300, and backrest structure 200 all have filling material, which can be sponge.

[0420] Preferably, the seat cushion structure 300 includes a hook (unmarked), the hook having an anti-slip portion (unmarked), and a hanging rod (unmarked) on the base 2 for hanging the hook. The hanging rod has at least two mating portions (unmarked). When the hook is hung on the hanging rod, the anti-slip portion abuts against one of the mating portions. In this application, the anti-slip portion abuts against one of the mating portions to prevent the seat cushion structure 300 from sliding relative to the base 2. When the hanging rod has at least two mating portions, the anti-slip portion abuts against different mating portions to achieve different positions on the hanging rod where the seat cushion structure 300 is fixed. That is, different models of seat cushion structures 300 can be fixedly connected to the hanging rod by abutting against different mating portions.

[0421] As shown in Figures 1, 10, and 11, the sofa control method includes the sofa described in this embodiment, and the sofa further includes:

[0422] The headrest structure 400 is movably mounted above the backrest structure 200;

[0423] The second drive mechanism 9 has one end rotatably connected to the backrest structure 200 and the other end rotatably connected to the headrest structure 400.

[0424] Control switch 5001 is electrically connected to the first drive mechanism 6 and the second drive mechanism 9;

[0425] Signal acquisition unit 5002 is used to collect electrical signals;

[0426] The controller 500, the signal acquisition unit 5002, and the control switch 5001 are electrically connected to the controller 500 respectively.

[0427] Sofa control methods include:

[0428] The signal acquisition unit 5002 transmits the acquired electrical signals to the controller 500. Based on the electrical signals, the controller 500 controls the first drive mechanism 6 and the second drive mechanism 9 to work through the control switch 5001, so that the mechanical extension structure 100 can change between a sitting position and a lying position, and the second drive mechanism 9 can adjust the position of the headrest structure 400 relative to the backrest structure 200.

[0429] In this application, the synchronous movement of the first drive mechanism 6 and the second drive mechanism 9 has the following beneficial effects: 1. It can reduce the time required for the sofa to change from its current posture position to a preset posture position; the control switch 5001 electrically connects the first drive mechanism 6 and the second drive mechanism 9, and the signal acquisition unit 5002 transmits the acquired electrical signals to the controller 500. Based on the electrical signals, the controller 500 controls the first drive mechanism 6 and the second drive mechanism 9 to work synchronously through the control switch 5001, thereby enabling the first drive mechanism 6 to achieve the fit between the sofa and the user's back, buttocks, and legs, and the second drive mechanism 9 to achieve the fit between the sofa and the user's head. 2. The signal acquisition unit 5002 realizes the sofa posture memory function, that is, the sofa can move to the preset posture with one click through the signal acquisition unit 5002.

[0430] In this application, the signal collector 5002 includes a voice acquisition module and / or a wireless signal receiving module. When the signal collector 5002 includes a voice acquisition module, the signal collector 5002 can acquire voice signals; when the signal collector 5002 includes a wireless signal receiving module, the signal collector 5002 can acquire wireless signals, which can be emitted by signal terminals such as mobile phones, tablets, handheld remote controls, and computers.

[0431] When a sofa comprises at least two seat units, and each seat unit includes a signal acquisition unit 5002, signal acquisition errors are prone to occur in signal acquisition units 5002 on adjacent seat units, especially since the signal acquisition unit 5002 includes a voice acquisition module. This application provides two voice signal acquisition schemes for sofas comprising two seat units:

[0432] 1. The sofa includes two seat units. The signal acquisition unit 5002 includes a first voice acquisition module and a second voice acquisition module. The first voice acquisition module is located in one of the seat units to collect a first electrical signal from that seat unit. The second voice acquisition module is located in the other seat unit to collect a second electrical signal from that seat unit. In this solution, the first and second voice acquisition modules achieve zoned voice acquisition, which enables individual voice control of each seat unit.

[0433] 2. The sofa includes two seat units. The signal acquisition unit 5002 includes a first voice acquisition module and a second voice acquisition module. The first voice acquisition module is adjacent to one of the seat units, and the second voice acquisition module is adjacent to the other seat unit. A signal comparison module is provided between the first voice acquisition module, the second voice acquisition module, and the controller 500. The signal comparison module is used to determine the magnitude of the voltage or current value of different electrical signals. The first electrical signal acquired by the first voice acquisition module and the second electrical signal acquired by the second voice acquisition module are respectively transmitted to the signal comparison module. The signal comparison module transmits one of the first electrical signal and the second electrical signal to the controller 500. The controller 500 controls the first drive mechanism on one of the seat units to work through the control switch 5001, so that the first drive mechanism on the seat unit adjusts the position of the base relative to the base. When a signal comparison module is provided between the first voice acquisition module, the second voice acquisition module, and the controller 500, the signal comparison module can determine the magnitude of the voltage values ​​of the first and second electrical signals, and transmit the result to the controller 500. The controller 500 presets an instruction (the preset instruction includes the controller 500 turning off the control switch 5001 on the seat unit corresponding to the electrical signal with the larger voltage value), and controls the control switch 5001 on one of the seat units to change from the open state to the closed state. For example, if the signal comparison module determines that the voltage value of the first electrical signal is greater than the voltage value of the second electrical signal, after receiving the information that the voltage value of the first electrical signal is greater than the voltage value of the second electrical signal, the controller 500 controls the first drive mechanism of the seat unit corresponding to the first electrical signal to work through the control switch 5001 of the seat unit corresponding to the first electrical signal, so as to realize that the first drive mechanism on the seat unit corresponding to the first electrical signal adjusts the position of the base relative to the base. Similarly, when a signal comparison module is provided between the first voice acquisition module, the second voice acquisition module, and the controller 500, the signal comparison module can determine the magnitude of the current value of the first electrical signal and the current value of the second electrical signal, and the signal comparison module can transmit the result to the controller 500. The controller 500 presets an instruction (the preset instruction includes the controller 500 turning off the control switch 5001 on the seat unit corresponding to the electrical signal with the larger current value), and controls the control switch 5001 on one of the seat units to change from the open state to the closed state. For example, if the signal comparison module determines that the current value of the first electrical signal is greater than the current value of the second electrical signal, after receiving the information that the current value of the first electrical signal is greater than the current value of the second electrical signal, the controller 500 controls the first drive mechanism of the seat unit corresponding to the first electrical signal to work through the control switch 5001 of the seat unit corresponding to the first electrical signal, so as to realize that the first drive mechanism on the seat unit corresponding to the first electrical signal adjusts the position of the base relative to the base.

[0434] As shown in Figures 1, 10, and 11, the sofa control method includes the sofa described in this embodiment, and the sofa further includes:

[0435] Gravity sensor 5003 is used to collect real-time gravity signals. Gravity sensor 5003 is installed in seat cushion structure 300 and / or backrest structure 200.

[0436] Control switch 5001 is electrically connected to the first drive mechanism 6;

[0437] Signal acquisition unit 5002 is used to acquire real-time voice signals;

[0438] The controller 500, gravity sensor 5003, signal acquisition unit 5002 and control switch 5001 are electrically connected to the controller 500 respectively;

[0439] Sofa control methods include:

[0440] When the gravity sensor 5003 collects a real-time gravity signal, the signal acquisition device 5002 is activated to collect a real-time voice signal.

[0441] The signal acquisition unit 5002 identifies the real-time voice signal to determine whether the real-time voice signal includes a wake word;

[0442] After determining that the real-time voice signal collected by the signal collector 5002 includes a wake-up word, the signal collector 5002 collects the real-time voice signal containing control commands and transmits the real-time voice signal containing control commands to the controller 500. Based on the real-time voice signal, the controller 500 controls the first drive mechanism 6 to work through the control switch 5001 so that the mechanical extension structure 100 can change between a sitting position and a lying position.

[0443] In this application, the gravity sensor 5003 is a prerequisite for the operation of the signal acquisition device 5002; that is, the signal acquisition device 5002 will only acquire wireless or voice signals if the gravity sensor 5003 acquires a gravity signal. As the number of smart home appliances in users' homes gradually increases, when the gravity sensor 5003 is a prerequisite for the operation of the signal acquisition device 5002, the probability of the sofa being erroneously activated will be greatly reduced. Erroneous activation of the sofa will cause the mechanical extension structure 100 to change between a sitting position and a reclining position.

[0444] In this application, the signal acquisition unit 5002, gravity sensor 5003, and ambient light 5004 can be used together: that is, the sofa also includes an ambient light 5004, which is electrically connected to the control switch 5001. The gravity sensor 5003 transmits the collected real-time gravity signal to the controller 500. After receiving the real-time gravity signal, the controller 500 turns on the ambient light 5004 through the control switch 5001. When the user sits on the seat cushion structure 300, the ambient light 5004 is automatically turned on to enhance the user's visual experience; after the user gets up and leaves the seat cushion structure 300, the ambient light 5004 is automatically turned off, eliminating the need for the user to turn off the ambient light 5004.

[0445] In this application, the first drive mechanism 6, the second drive mechanism 9, and the ambient light 5004 are electrically connected to the control switch 5001. However, the control switch 5001 can be adjusted according to actual needs. For example, the control switch 5001 may include a first switch, a second switch, and a third switch, wherein the first switch connects the first drive mechanism 6 to the controller 500, the second switch connects the second drive mechanism 9 to the controller 500, and the third switch connects the ambient light 5004 to the controller 500; the control switch 5001 may also include a first switch and a second switch, wherein the first switch connects the first drive mechanism 6 and the second drive mechanism 9 to the controller 500, and the second switch connects the ambient light 5004 to the controller 500; the control switch 5001 may also include a first switch, wherein the first switch connects the first drive mechanism 6, the second drive mechanism 9, and the ambient light 5004 to the controller 500.

[0446] In this application, the signal acquisition unit 5002, gravity sensor 5003, ambient light 5004, and photosensitive sensor 5005 can also be used together: the sofa also includes ambient light 5004 and photosensitive sensor 5005 for acquiring real-time light signals. Ambient light 5004 is electrically connected to control switch 5001, and photosensitive sensor 5005 is electrically connected to controller 500. Controller 500 presets a specified light signal and a specified gravity signal. Gravity sensor 5003 transmits the acquired real-time gravity signal to controller 500, and photosensitive sensor 5005 transmits the acquired real-time light signal to controller 500. After comparing the specified gravity signal with the real-time gravity signal and the specified light signal with the real-time light signal, controller 500 turns ambient light 5004 on or off via control switch 5001. When the photosensor 5005 detects daylight (daylight time can be between 8:00 and 17:00), the ambient light 5004 will not be turned on; when the photosensor 5005 detects darkness (darkness time can be between 20:00 and 4:00), the ambient light 5004 will be turned on.

[0447] In this application, the working order of the photosensor 5005 and the gravity sensor 5003 is not limited, and their working order can be adjusted according to requirements. In this application, the gravity signal is specified to be non-zero, that is, the gravity is not equal to zero kilograms. When the specified gravity signal is non-zero, the sofa will not be erroneously activated when pets or objects are located above it.

[0448] In a preferred embodiment of this application, the gravity sensor 5003 transmits the collected real-time gravity signal to the controller 500. After the controller 500 determines that the specified gravity signal value is greater than the real-time gravity signal value, it receives the real-time light signal collected by the photosensitive sensor 5005. After the controller 500 determines that the specified light signal value is greater than the real-time light signal value, it illuminates the ambient light 5004 via the control switch 5001. For example, if the specified gravity signal is 20 kg and the specified light signal value is 100 cd / m², first, the controller 500 collects the real-time gravity signal; then, after the controller 500 determines that the real-time gravity signal value is less than 20 kg, it receives the real-time light signal collected by the photosensitive sensor 5005; finally, after the controller 500 determines that the real-time light signal value is less than 100 cd / m², it illuminates the ambient light 5004 via the control switch 5001. This solution allows the ambient light 5004 to automatically turn on when a user gets up from the sofa after dark, preventing the user from tripping over furniture in the home.

[0449] Of course, the Ambient Light 5004 can be turned on when the user sits behind the sofa, and it can also be used to light up during the day.

[0450] As shown in Figures 1, 10, and 11, the ambient light 5004 can also be used on sofas without a signal acquisition unit 5002. That is, the sofa control method includes the sofa described in this embodiment, and the sofa further includes:

[0451] Ambient light 5004 is installed on seat cushion structure 300 and / or backrest structure 200;

[0452] Gravity sensor 5003 is used to collect real-time gravity signals. Gravity sensor 5003 is installed in seat cushion structure 300 and / or backrest structure 200.

[0453] The 5005 photosensitive sensor is used to collect real-time optical signals.

[0454] Control switch 5001 is electrically connected to the first drive mechanism 6 and ambient light 5004;

[0455] The controller 500, gravity sensor 5003, photosensitive sensor 5005 and control switch 5001 are electrically connected to the controller 500 respectively;

[0456] Sofa control methods include:

[0457] The controller 500 presets a specified light signal and a specified gravity signal. The gravity sensor 5003 transmits the collected real-time gravity signal to the controller 500, and the photosensitive sensor 5005 transmits the collected real-time light signal to the controller 500. After comparing the specified gravity signal with the real-time gravity signal and the specified light signal with the real-time light signal, the controller 500 turns the ambient light 5004 on or off via the control switch 5001.

[0458] As shown in Figures 1, 10, and 11, after the user leaves the sofa, the mechanical extension structure 100 can automatically move to a sitting position. That is, the sofa control method includes the sofa described in this embodiment. The sofa also includes:

[0459] Gravity sensor 5003 is used to collect real-time gravity signals. Gravity sensor 5003 is installed in seat cushion structure 300 and / or backrest structure 200.

[0460] The first position sensor 67 is electrically connected to the first drive mechanism 6, and the first position sensor 67 is used to collect the first real-time position signal of the first drive mechanism 6.

[0461] Control switch 5001 is electrically connected to the first drive mechanism 6;

[0462] The controller 500, the first position sensor 67, the gravity sensor 5003 and the control switch 5001 are electrically connected to the controller 500 respectively;

[0463] Sofa control methods include:

[0464] The controller 500 presets a first designated position signal. When the gravity sensor 5003 fails to collect the real-time gravity signal, the controller 500 collects the first real-time position signal of the first position sensor 67 and determines whether the mechanical extension structure 100 is in a seated position by comparing the first designated position signal with the first real-time position signal.

[0465] When the controller 500 determines that the mechanical extension structure 100 is in a seated position, the controller 500 stops the first drive mechanism 6 from working through the control switch 5001; when the controller 500 determines that the mechanical extension structure 100 is not in a seated position, the controller 500 controls the first drive mechanism 6 to work through the control switch 5001, and the first drive mechanism 6 adjusts the position of the base 2 relative to the base 1 until the mechanical extension structure 100 is in a seated position.

[0466] In this application, the gravity sensor 5003 is constantly collecting real-time gravity signals. When the gravity sensor 5003 fails to collect real-time gravity signals, the controller 500 will collect a first real-time position signal through the first position sensor 67. The controller 500 determines the position information of the mechanical extension structure 100 by comparing the magnitude of the first designated position signal and the first real-time position signal. For example, the value of the first designated position signal is the electrical signal value of the mechanical extension structure 100 in a seated position. When the value of the first real-time position signal is greater than the value of the first designated position signal, it can be determined that the mechanical extension structure 100 is not in a seated position. When the controller 500 determines that the mechanical extension structure 100 is not in a seated position based on the position signal, the controller 500 connects the power supply of the control switch 5001 and makes the first drive mechanism 6 work, so as to realize that the first drive mechanism 6 adjusts the position of the base 2 relative to the base 1 until the mechanical extension structure 100 is in a seated position. This design makes it easier for the next user to sit on the sofa and also increases the service life of the mechanical extension structure 100 (when the mechanical extension structure 100 is in a sitting position, the swing mechanism 7, backrest assembly 4, and leg assembly 5 will be limited and supported by multiple limit rods, and the swing mechanism 7, backrest assembly 4, and leg assembly 5 will also be supported and limited by multiple support rods).

[0467] As shown in Figures 1, 10, and 11, the sofa has the function of automatically returning to a sitting position after the user gets up. That is, the sofa control method includes the sofa described in this embodiment. The sofa also includes:

[0468] Gravity sensor 5003 is used to collect real-time gravity signals. Gravity sensor 5003 is installed in seat cushion structure 300 and / or backrest structure 200.

[0469] The first position sensor 67 is electrically connected to the first drive mechanism 6, and the first position sensor 67 is used to collect the first real-time position signal of the first drive mechanism 6.

[0470] Control switch 5001 is electrically connected to the first drive mechanism 6;

[0471] Timer module 5006 is used to calculate the real-time gravity signal acquisition time;

[0472] The controller 500, the first position sensor 67, the gravity sensor 5003, the control switch 5001 and the timer module 5006 are electrically connected to the controller 500 respectively;

[0473] Sofa control methods include:

[0474] The controller 500 presets the first designated position signal and the real-time gravity signal acquisition time. When the mechanical extension structure 100 is not in the sitting position, the controller 500 acquires the real-time gravity signal for the first time through the gravity sensor 5003.

[0475] When the gravity sensor 5003 fails to collect a real-time gravity signal for the first time, the timer module 5006 starts working. After the timer module 5006 reaches the real-time gravity signal collection time, the controller 500 collects the first real-time position signal of the first position sensor 67 and determines whether the mechanical extension structure 100 is in a seated position by comparing the first designated position signal with the first real-time position signal. When the controller 500 determines that the mechanical extension structure 100 is not in a seated position, the controller 500 controls the first drive mechanism 6 to work through the control switch 5001. The first drive mechanism 6 adjusts the position of the base 2 relative to the base 1 until the mechanical extension structure 100 is in a seated position.

[0476] In this application, when the mechanical extension structure 100 is not in a seated position, the gravity sensor 5003 continuously collects real-time gravity signals (in this technical solution, when the mechanical extension structure 100 is in a seated position, the gravity sensor 5003 can continuously collect gravity signals, or it can collect gravity signals at intervals). After the user leaves the sofa, the gravity sensor 5003 will be unable to collect real-time gravity signals. When the gravity sensor 5003 is unable to collect real-time gravity signals, the timer module 5006 starts working, and the mechanical extension structure 100 will automatically return to a seated position after the timer module 5006 reaches the preset real-time gravity signal collection time, so as to facilitate the next user sitting on the sofa.

[0477] As shown in Figures 1, 10, and 11, to prevent users from temporarily getting up (e.g., to get water, snacks, or their phones) but then needing to remain seated, the sofa incorporates a secondary gravity signal acquisition function. In other words, the sofa's control method includes the features described in this embodiment. The sofa also includes:

[0478] Gravity sensor 5003 is used to collect real-time gravity signals. Gravity sensor 5003 is installed in seat cushion structure 300 and / or backrest structure 200.

[0479] The first position sensor 67 is electrically connected to the first drive mechanism 6, and the first position sensor 67 is used to collect the first real-time position signal of the first drive mechanism 6.

[0480] Control switch 5001 is electrically connected to the first drive mechanism 6;

[0481] Timer module 5006 is used to calculate the real-time gravity signal acquisition time;

[0482] The controller 500, the first position sensor 67, the gravity sensor 5003, the control switch 5001 and the timer module 5006 are electrically connected to the controller 500 respectively;

[0483] Sofa control methods include:

[0484] The controller 500 presets the first designated position signal and the real-time gravity signal acquisition time. When the mechanical extension structure 100 is not in the sitting position, the controller 500 acquires the real-time gravity signal for the first time through the gravity sensor 5003.

[0485] When the gravity sensor 5003 fails to collect the real-time gravity signal for the first time, the timer module 5006 starts working. After the timer module 5006 reaches the real-time gravity signal collection time, the controller 500 collects the real-time gravity signal for the second time through the gravity sensor 5003.

[0486] When the gravity sensor 5003 fails to collect a gravity signal for the second time, the controller 500 collects the first real-time position signal of the first position sensor 67 and determines whether the mechanical extension structure 100 is in a seated position by comparing the first designated position signal with the first real-time position signal. When the controller 500 determines that the mechanical extension structure 100 is not in a seated position, the controller 500 controls the first drive mechanism 6 to work through the control switch 5001. The first drive mechanism 6 adjusts the position of the base 2 relative to the base 1 until the mechanical extension structure 100 is in a seated position.

[0487] In this application, when the mechanical extension structure 100 is not in a seated position, the gravity sensor 5003 continuously collects real-time gravity signals. If the user leaves the sofa to retrieve an item, the gravity sensor 5003 will initially fail to collect a real-time gravity signal. When the gravity sensor 5003 fails to collect a real-time gravity signal for the first time, the timer module 5006 starts working. If the user sits back on the sofa before the timer module 5006 reaches the real-time gravity signal collection time, meaning the controller 500 collects a real-time gravity signal for the second time through the gravity sensor 5003, then the timer module 5006 stops working, and the gravity sensor 5003 restarts working to ensure that the first real-time gravity signal is always collected. If the user does not sit back on the sofa before the timer module 5006 reaches the real-time gravity signal collection time, meaning the controller 500 fails to collect a real-time gravity signal for the second time through the gravity sensor 5003, the controller 500 will begin to determine whether the mechanical extension structure 100 is in a seated position.

[0488] In this application, the controller 500 determines whether the mechanical extension structure 100 is in a seated position primarily through the first position sensor 67. The first position sensor 67 can be used to detect the rotation angle and number of revolutions of the motor shaft 611, the rotation angle and number of revolutions of the inner rod 661, the extension / retraction position of the outer rod 662, the rotation angle of the lead screw, and the position of the slider 63.

[0489] Similarly, the second position sensor 91 also has the same function as the first position sensor 67.

[0490] As shown in Figures 1, 10, and 11, the sofa has a memory function, meaning the sofa control method includes the sofa described in this embodiment. The sofa also includes:

[0491] The headrest structure 400 is movably mounted above the backrest structure 200;

[0492] The second drive mechanism 9 has one end rotatably connected to the backrest structure 200 and the other end rotatably connected to the headrest structure 400.

[0493] Control switch 5001 is electrically connected to the first drive mechanism 6 and the second drive mechanism 9;

[0494] The first position sensor 67 is electrically connected to the first drive mechanism 6, and the first position sensor 67 is used to collect the first real-time position signal of the first drive mechanism 6.

[0495] The second position sensor 91 is electrically connected to the second drive mechanism 9, and the second position sensor 91 is used to collect the second real-time position signal of the second drive mechanism 9.

[0496] The controller 500, the first position sensor 67, the second drive mechanism 9 and the control switch 5001 are electrically connected to the controller 500;

[0497] Sofa control methods include:

[0498] The controller 500 presets a first designated position signal and a second designated position signal. The first position sensor 67 transmits the first real-time position signal it has collected to the controller 500, and the second position sensor 91 transmits the second real-time position signal it has collected to the controller 500. After comparing the first real-time position signal with the first designated position signal and comparing the second real-time position signal with the second designated position signal, the controller 500 drives the first drive mechanism 6 and the second drive mechanism 9 to work through the control switch 5001, so that the mechanical extension structure 100 changes between a sitting position and a reclining position, and the second drive mechanism 9 adjusts the position of the headrest structure 400 relative to the backrest structure 200.

[0499] In this application, when the first real-time position signal is the same as the first designated position signal and the second real-time position signal is the same as the second designated position signal, the mechanical extension structure 100 will move to the position preset by the user so that the sofa can reach the designated posture by a physical or virtual button.

[0500] In this application, the first designated position signal records the rotation angle and number of revolutions of the motor shaft 611. The second drive mechanism 9 can adopt the structure of the first drive mechanism 6 as shown in Figure 6, or the second drive mechanism 9 can adopt the structure of the first drive mechanism 6 as shown in Figures 8 and 9. That is to say, the second designated position signal records the rotation angle and number of revolutions of the motor shaft on the second drive mechanism 9.

[0501] As shown in Figures 1, 10, and 11, the sofa enhances the anti-pinch function of the mechanical extension structure 100 in two ways. The first method involves a control method for the sofa as described in this embodiment, and the sofa further includes:

[0502] Anti-pinch sensor 5007 is used to detect the real-time electrical signal of the first drive mechanism 6;

[0503] Control switch 5001 is electrically connected to the first drive mechanism 6;

[0504] The controller 500, the anti-pinch sensor 5007, and the control switch 5001 are electrically connected to the controller 500.

[0505] Sofa control methods include:

[0506] The controller 500 presets a reference electrical signal. The anti-pinch sensor 5007 transmits the collected real-time electrical signal to the controller 500. The controller 500 compares the real-time electrical signal with the reference electrical signal. When the real-time electrical signal is greater than or equal to the reference electrical signal, the controller 500 drives the first drive mechanism 6 through the control switch 5001 to change the mechanical extension structure 100 to a lying position.

[0507] As shown in Figures 1, 10, and 11, the sofa enhances the anti-pinch function of the mechanical extension structure 100 in two ways. The second method includes the sofa control method described in this embodiment, and the sofa further includes:

[0508] Anti-pinch sensor 5007 is used to detect the real-time electrical signal of the first drive mechanism 6;

[0509] Control switch 5001 is electrically connected to the first drive mechanism 6;

[0510] The controller 500, the anti-pinch sensor 5007, and the control switch 5001 are electrically connected to the controller 500.

[0511] Sofa control methods include:

[0512] The controller 500 presets a reference electrical signal. The anti-pinch sensor 5007 transmits the first real-time electrical signal and the second real-time electrical signal it has collected to the controller 500. The controller 500 compares the reference electrical signal with the difference between the first real-time electrical signal and the second real-time electrical signal. When the difference between the first real-time electrical signal and the second real-time electrical signal is greater than or equal to the reference electrical signal, the controller 500 drives the first drive mechanism 6 through the control switch 5001 to change the mechanical extension structure 100 to a lying position.

[0513] In this application, the real-time electrical signal can be a current signal or a voltage signal. The installation position of the anti-pinch sensor 5007 can also be adjusted according to requirements; for example, the anti-pinch sensor 5007 can be installed on the leg assembly 5, the swing mechanism 7, or the backrest assembly 4.

[0514] As shown in Figures 1, 10, and 11, the sofa can switch between a sitting and reclining position via a single physical button using the mechanical extension structure 100. That is, the sofa control method includes the sofa described in this embodiment. The sofa also includes:

[0515] The controller 500 includes an interactive processing unit, which has a signal input terminal and a signal output terminal.

[0516] The display unit is used to display the navigation menu and sub-menus, and the signal output terminal of the interactive processing unit is connected to the display unit.

[0517] The operation button is connected to the signal input terminal of the interactive processing unit. Pressing or rotating an operation button will cause the display unit to display the corresponding menu information.

[0518] Sofa control methods include:

[0519] S01) Press the operation button in navigation mode to enter the submenu of the current menu item, enter the editing mode of the current menu item, or return to the parent menu of the current menu item. If entering the submenu or returning to the parent menu, return to step S03). If entering the editing mode, proceed to step S02.

[0520] S02) In edit mode, rotate the operation button to modify the parameters, and press the operation button to confirm that the parameter modification is complete.

[0521] S03) Press the operation button to enter the submenu or return to the previous menu.

[0522] As shown in Figures 19 and 21, the mechanical extension structure 100 disclosed in other embodiments of this application also includes a connecting structure 153 and a first driving device 15. The connecting structure 153 is fixedly connected to two sets of leg assemblies 5. The connecting structure 153 includes a swing plate 1531 that is rotatably connected to the first driving device 15.

[0523] The mechanical extension structure 100 also includes two sets of sliding mechanisms 16. Each set of sliding mechanisms includes at least two guides 161 and at least two sections of track 162. One of the guides 161 and the track 162 is fixedly connected to the base 2, and the other is fixedly connected to the base 1. The guides 161 are inserted into the track 162, and at least part of the track 162 is clearance-fitted with the guides 161. During the process of changing between a sitting position and a lying position, the guides 161 can slide along the first guide surface 16221 or the second guide surface 16222.

[0524] In this application, the mechanical extension structure 100 further includes a guide 161 and a track 162. The guide 161 is inserted into the track 162. During the transition between a sitting position and a lying position, the guide 161 slides along the first guide surface 16221 or the second guide surface 16222, thereby replacing the "roller rolling" technology in related technologies with the "guide sliding" technology. The advantages of the guide 161 sliding along the track 162 include: 1. The guide 161 is fixedly connected to the base 2 or the base 1, therefore, the guide 161 slides along the track 162. During the process, it is difficult for the guide 161 to generate movement noise between itself and the base 2 (or the base 1); 2. The surface of the guide 161 (the surface of the guide 161 that contacts the base 2) is covered by the track 162, so foreign objects are unlikely to fall onto its surface, that is, it is difficult for foreign objects to adhere to the surface of the guide 161 that contacts the base 2; 3. The gravity of the guide 161 is downward, and the gravity of the damaged guide 161 is still downward. Therefore, regardless of whether the guide 161 is damaged, its center of gravity will not shift during the sliding process of the guide 161 along the track 162. In other words, the "guide 161 sliding" technology effectively overcomes problems such as rolling noise, foreign object adhesion, and eccentric rolling, so as to improve the user experience, especially the user experience during the operation of the seat unit (the operation of the seat unit is the process of the base 2 moving back and forth relative to the base 1).

[0525] In this application, the mechanical extension structure includes a first drive unit 15, which drives the base 2 to slide along the track 162 via the leg assembly 5. This structure reduces the manufacturing cost of the seat unit by "reducing the number of first drive units and reducing a set of on / off switches".

[0526] In this application, the driving force required for the movement of the leg assembly 5 is significantly reduced by "at least a portion of the track 162 engaging with the guide 161 with a clearance fit". With the reduced driving force required for the movement of the leg assembly 5, the seat unit can adopt a single first drive unit 15 configuration.

[0527] In this application, reliability and manufacturing cost are balanced by "the guide 161 sliding along the first guide surface 16221 or the second guide surface 16222" and "the seat unit adopting a single first drive device 15".

[0528] Figure 19 shows the mechanical extension structure 100 in a seated position; Figure 21 shows the mechanical extension structure 100 in a reclining position; Figure 20 shows the position of the guide 161 on the track 162 when the mechanical extension structure 100 is in a seated position, and the position of the guide 161 on the track 162 when the mechanical extension structure 100 is in a reclining position. Therefore, two guides 161 are provided on one track 162. The left side of the track 162 shows the position of the guide 161 on the track 162 when the mechanical extension structure 100 is in a reclining position, and the right side of the track 162 shows the position of the guide 161 on the track 162 when the mechanical extension structure 100 is in a seated position.

[0529] As shown in Figure 20, when the mechanical extension structure 100 is in a seated position, the guide 161 is located at position P1 on the right side of the track 162; when the mechanical extension structure 100 is in a reclining position, the guide 161 is located at position P2 on the left side of the track 162.

[0530] The rotatable connection between the swing plate 1531 and the first drive rod 152 is the first transition point 11. When the mechanical extension structure 100 is in a seated position, the first transition point 11 is located at P3, as shown in Figures 15, 17, 19 and 20; when the mechanical extension structure 100 is in a reclining position, the first transition point 11 is located at P4, as shown in Figures 18 and 21; the straight-line distance between P1 and P2 is less than the straight-line distance between P3 and P4.

[0531] It is not difficult to conclude from the fact that “the straight-line distance between P1 and P2 is less than the straight-line distance between P3 and P4” that the length of track 162 and the length of swing plate 1531 determine the extension length of leg assembly 5.

[0532] As shown in Figure 20, the track 162 is fixedly connected to the base 1. The track 1622 is provided with a groove 1622. The guide 161 can be inserted into the groove 1622. The groove 1622 includes a first guide surface 16221 and a second guide surface 16222 corresponding to the first guide surface 16221. During the process of the mechanical extension structure 100 changing between the sitting position and the lying position, the guide 161 can slide along the first guide surface 16221 or the second guide surface 16222, so that the base 2 slides along the base 1.

[0533] In this application, each track 162 is provided with a first guide surface 16221 and a second guide surface 16222. Each guide 161 is located between the first guide surface 16221 and the second guide surface 16222 of a track 162. At least part of the track 162 and the guide 161 are in clearance fit. During the process of the mechanical extension structure 100 changing between a sitting position and a lying position, the guide 161 can move along the first guide surface 16221 or the second guide surface 16222. Based on the statement that "during the transition between a sitting and lying position, the guide 161 can slide along the first guide surface 16221 or the second guide surface 16222", it is easy to conclude that at least part of the guide 161 is clearance-fitted with the slide groove 1622, as shown in Figure 22. That is, during the transition between a sitting and lying position, the guide 161 will not be interference-fitted with the track 162 throughout the entire transition. This structure can effectively reduce the friction of the guide 161 during its movement along the track 162.

[0534] Of course, the most preferred option is that the guide 161 does not have an interference fit with the track 162 throughout the entire process.

[0535] When the guide 161 is located at the arc transition between the inclined section and the straight section, and the guide 161 and the track 162 are in an interference fit, the arc transition between the inclined section and the straight section can physically forcefully change the movement trajectory of the guide 161 to prevent the guide 161 from separating from the track 162.

[0536] In this context, the horizontal plane is the front-to-back direction of Figure 16; the inclined segment uses either its centerline or its upper end face as the measurement reference to measure the angle between the inclined segment and the upper end face 113 of the base 2; the straight segment uses either its centerline or its upper end face as the measurement reference to measure the angle between the straight segment and the upper end face 113 of the base 2; and the first track 1601 uses either its centerline or its upper end face as the measurement reference to measure the angle between the first track 1601 and the upper end face 113 of the base 2.

[0537] In related technologies, the mechanical extension structure includes a guide, typically a slider. A track is provided on the base, and the guide is inserted into the track with an interference fit. During the transition between a sitting and reclining position, the guide slides along the track, enabling the base to move back and forth relative to the seat. While the interference fit between the guide and the track increases stability during this movement, it also increases friction during the guide's sliding motion. Increased friction along the track slows down the guide's movement, potentially negatively impacting the user experience of the seat unit.

[0538] As shown in Figure 19, at least two tracks 162 are a first track 1601 and a second track 1602, respectively, and the first track 1601 and the second track 1602 are respectively provided on both sides of the base 2. In Figure 19, the first track 1601 is not connected to the second track 1602; however, in this application, the first track 1601 can also be connected to the second track 1602 according to actual needs.

[0539] Preferably, in this application, when the mechanical extension structure 100 is in a seated position, the track 162 and the guide 161 are in a clearance fit; when the mechanical extension structure 100 is in a reclining position, the track 162 and the guide 161 are in a clearance fit. When the mechanical extension structure 100 is in a seated position and the track 162 and the guide 161 are in a clearance fit, the initial driving force required for the leg assembly 5 to extend can be significantly reduced. When the mechanical extension structure 100 is in a reclining position and the track 162 and the guide 161 are in a clearance fit, the initial driving force required for the leg assembly 5 to retract can be significantly reduced.

[0540] However, this application does not exclude the choice between "when the mechanical extension structure 100 is in a seated position, the track 162 and the guide 161 are in clearance fit" and "when the mechanical extension structure 100 is in a reclining position, the track 162 and the guide 161 are in clearance fit".

[0541] In this application, each sliding mechanism 16 includes a first guide, a second guide, a first track 1601, and a second track 1602; wherein, as shown in FIG19, the guide 161 located in the first track 1601 is the first guide, and the guide 161 located in the second track 1602 is the second guide; when the mechanical extension structure 100 is in a seated position, the first guide is inserted into the first track 1601, and the second guide is inserted into the second track 1602, wherein at least a portion of the second track 1602 is located below the first track 1601, and / or at least a portion of the second guide is located below the first guide.

[0542] As shown in Figure 20, "at least part of the second track 1602 is located below the first track 1601" means that the second track 1602 on the side closer to the first track 1601 is located below the first track 1601. It can also be seen in Figure 20 that at least part of the second guide is located below the first guide.

[0543] Since at least part of the second guide is located below the first guide, the orientation of the front of the base 2 can be adjusted when the mechanical extension structure 100 is in a seated position. Preferably, the front of the base 2 can be tilted slightly downward, which makes it convenient for young and old users to get up from the seat.

[0544] Preferably, the two sets of sliding mechanisms 16 are mirror images of each other on both sides of the base 2. The base 2 and / or the second track 1602 are provided with a first limiting structure 1621 to prevent the second guide from sliding outside the second track 1602 and separating from the second track 1602. When the mechanical extension structure 100 is in a seated position, the second guide abuts against the first limiting structure 1621.

[0545] In this application, when the mechanical extension structure 100 is in a seated position and the second guide abuts against the first limiting structure 1621, the initial position of the first driving device 15 is determined to reduce the probability of accumulated error of the first driving device 15.

[0546] Furthermore, in related technologies, to prevent the guide from sliding outside the track, the length of the track can be increased; however, in this application, a first limiting structure 1621 is provided on the second track 1602 (or the first limiting structure 1621 is provided on the base 2, or the first limiting structure 1621 is provided on both the base 2 and the second track 1602). The first limiting structure 1621 is used to prevent the guide 161 from sliding outside the track 162 and separating from the track 162; that is, the first limiting structure 1621 uses a physical structure to prevent the guide 161 from derailing, thereby improving the reliability of the seat unit during operation.

[0547] In this application, a buffer pad is provided on the second track 1602. The hardness of the buffer pad is less than that of the first limiting structure. The buffer pad is preferably made of flexible materials such as sponge or foam board, which are common and easy to understand. Therefore, the buffer pad is not shown in the attached drawings. When the mechanical extension structure 100 is in a sitting position, the second guide does not abut against the buffer pad. When the mechanical extension structure 100 is in a lying position, the second guide abuts against the buffer pad, and the buffer pad is located between the second guide and the first limiting structure 1621.

[0548] As shown in Figures 20 and 21, a buffer pad is provided on the second track 1602 on the side away from the first track 1601, and the first limiting structure 1621 on the side away from the first track 1601 fits the buffer pad.

[0549] Preferably, the cushioning pad is detachably mounted on the second track 1602. This structure facilitates the replacement of the cushioning pad and prevents it from losing its elasticity and failing to provide cushioning.

[0550] This application discloses two mechanical extension structures 100, of which Figures 15-18 disclose one type of mechanical extension structure, and Figures 19-21 disclose the other type of mechanical extension structure. Specifically, the guide 161 includes two structures: the first type of guide 161 is shown in Figure 16, and the second type of guide 161 is shown in Figure 19.

[0551] As shown in Figure 16, the first type of guide 161 includes a fixed rod 1611 and a sliding rod 1612. The fixed rod 1611 is fixedly connected to the base 2, and the track 162 is fixedly connected to the base 1. The fixed rod 1611 and the track 162 are slidably connected to the sliding rod 1612. During the process of the mechanical extension structure 100 changing between a sitting position and a lying position, the fixed rod 1611 slides along the track 162 through the sliding rod 1612. The sliding rod 1612 is provided with a limiting part 16121 that can be used to abut against the first limiting structure 1621. The hardness of the limiting part 16121 is different from the hardness of the first limiting structure 1621.

[0552] Preferably, the track 162 is made of metal, and the first limiting structure 1621 is a first limiting block extending inward from the track 162, as shown in Figure 16; the sliding rod 1612 is made of plastic, and there are two sliding rods 1612. Of course, the sliding rod in this application can be a single rod, and the limiting part of the sliding rod can be made of plastic.

[0553] In addition, the first limiting structure 1621 can be integrally formed with the track 162, as shown in Figure 20.

[0554] Since the hardness of the limiting part 16121 is different from that of the first limiting structure 1621, during the process of the limiting part 16121 abutting against the first limiting structure 1621, the limiting part 16121 is used to dissipate part of the impact force of the sliding rod 1612 hitting the first limiting structure 1621, so as to further improve the user's experience during the operation of the seat unit.

[0555] As shown in Figure 16, the fixed rod 1611 is provided with a second limiting structure 16111 to prevent the sliding rod 1612 from sliding outside the fixed rod 1611 and separating from the fixed rod 1611.

[0556] When the guide 161 includes a fixed rod 1611 and a sliding rod 1612, the sliding rod 1612 is used to increase the range of motion of the base 2 relative to the base 1; while the second limiting structure 16111 is used in conjunction with the first limiting structure 1621 to limit the maximum distance that the guide 161 can move relative to the track 162.

[0557] In this application, the hardness of the second limiting structure 16111 is different from that of the limiting part 16121. When the fixed rod 1611 and the track 162 are slidably connected to the sliding rod 1612, the limiting part 16121 can be clamped between the first limiting structure 1621 and the second limiting structure 16111.

[0558] When the limiting part 16121 is clamped between the first limiting structure 1621 and the second limiting structure 16111, it can be observed whether the guide 161 and the track 162 are assembled according to the specifications.

[0559] Since the hardness of the limiting part 16121 is different from that of the second limiting structure 16111, during the process of the limiting part 16121 abutting against the second limiting structure 16111, the limiting part 16121 is used to dissipate part of the impact force of the sliding rod 1612 hitting the second limiting structure 16111, so as to further improve the user's experience during the operation of the seat unit.

[0560] Preferably, the second limiting structure 16111 is a second limiting block formed by the downward extension of the fixing rod 1611.

[0561] The seat unit includes a backrest structure 200 and a seat cushion structure 300. During the process of the mechanical extension structure 100 changing from a sitting position to a reclining position, the seat cushion structure 300 continuously compresses the backrest structure 200, meaning that the seat cushion structure 300 and the backrest structure 200 partially overlap in the vertical direction. Therefore, when the mechanical extension structure 100 is in the sitting position, even if the second guide impacts the first limiting structure 1621, the user's perception will not be very obvious. However, during the process of the mechanical extension structure 100 changing from a reclining position to a sitting position, the seat cushion structure 300 moves away from the backrest structure 200. Therefore, when the mechanical extension structure 100 is in the reclining position, the second guide impacts the first limiting structure 1621 through the buffer pad, thereby reducing the user's perception.

[0562] As shown in Figures 19 and 20, the first track 1601 and the second track 1602 are set at an angle, and the angle between the first track 1601 and the horizontal plane is less than the angle between the second track 1602 and the horizontal plane.

[0563] The first track 1601 and the second track 1602 have the same tilt direction.

[0564] As shown in Figure 20, the "angle between the first track 1601 and the horizontal plane" is the angle between the first guide surface 16221 (or the second guide surface 16222) of the first track 1601 and the horizontal plane; similarly, the "angle between the second track 1602 and the horizontal plane" is the angle between the first guide surface 16221 (or the second guide surface 16222) of the second track 1602 and the horizontal plane.

[0565] Currently, seat units are developing towards comfort and zero back rubbing. To achieve this goal, it is usually necessary to slow down the rate of increase of the vertical height difference between the front and rear of the base 2. "The angle between the first track 1601 and the horizontal plane is less than the angle between the second track 1602 and the horizontal plane, and the tilt directions of the first track 1601 and the second track 1602 are the same" effectively improves the problem of the rapid increase of the vertical height difference during the movement of the base 2 relative to the base 1.

[0566] As shown in Figure 19, when the mechanical extension structure 100 is in a seated position, the angle between the upper end face 113 of the base 2 and the horizontal plane is -10°≤12°. Elderly users of different ages can adjust the angle between the upper end face 113 of the base 2 and the horizontal plane according to their physical condition to reduce the difficulty of getting up.

[0567] As shown in Figure 19, the second track 1602 includes an inclined section 168 and a straight section 169. The inclined section 168 and the straight section 169 are connected by an arc. When the mechanical extension structure 100 is in a seated position, 5° < the angle between the inclined section 168 and the upper end face 113 of the base 2 < 45°; when the mechanical extension structure 100 is in a reclining position, 3° ≤ the angle between the upper end face 113 of the base 2 and the horizontal plane < 10°.

[0568] Among them, the horizontal plane is the front-back direction of Figure 17 and the horizontal plane is the front-back direction of Figure 20; the inclined segment 168 uses one of its center line and upper end face as the measurement reference to realize the angle between the inclined segment 168 and the upper end face 113 of the base 2.

[0569] Extensive market research has shown that the most comfortable angle for a user to lie on the seat unit is when 3° ≤ the angle between the upper end face 113 of the base 2 and the horizontal plane is < 10°. Since the movement distance of the guide 161 is controlled by the swing plate 1531, in order to allow the base 2 to move to the most comfortable angle of the seat unit within the limited travel of the track 162, the track 162 of this application includes an inclined section 168. The inclined section 168 is set to a specific inclined angle (specific inclined angle: 5° < the angle between the inclined section 168 and the upper end face 113 of the base 2 < 45°), so as to achieve the most comfortable angle for the seat unit within the limited travel of the track 162.

[0570] Preferably, 7cm < swing plate 1531 < 30cm, and during the transition between the sitting and reclining positions of the mechanical extension structure 100, the swing plate 1531 is located above the lower end face of the base 1. This structure reduces the probability of the swing plate 1531 colliding with external objects during transportation, especially when the seat unit has removed the support rod 18.

[0571] The angle between the inclined segment 168 and the horizontal plane is greater than the angle between the straight segment 169 and the horizontal plane. This "angle between the inclined segment 168 and the horizontal plane is greater than the angle between the straight segment 169 and the horizontal plane" allows the user to experience a certain degree of weightlessness and zero gravity in the initial stage when the mechanical extension structure 100 changes from a sitting position to a lying position, so as to meet the user's need to quickly adjust the seat posture.

[0572] The guide 161 has an arc surface that contacts the track 162, as shown in Figure 20. The outer contour of the guide 161 is circular, and in this case, the guide 161 is in line contact with the track 162. Of course, the outer contour of the guide 161 can also be elliptical, or the outer contour of the guide 161 can consist of only a segment of an arc.

[0573] In this application, the guide 161 can also contact the surface of the track 162, that is, at least one sliding surface is provided on the guide 161, and the sliding surface abuts against the track 162. Of course, the outer contour of the guide 161 can also be polygonal. The "contact between the guide 161 and the surface of the track 162" is used to further increase the stability of the guide 161 during the sliding process and to increase the wear resistance of the guide 161, so as to effectively extend the service life of a single guide 161.

[0574] In this application, the guide 161 is fixedly connected to the base 2, and the guide 161 is detachably disposed on the base 2. As a vulnerable component, the guide 161 can be replaced by disassembly and assembly.

[0575] Preferably, the guide 161 is threadedly connected to the base 2, and / or, when the guide 161 is fixedly connected to the base 2, an annular gasket 1614 is clamped between the guide 161 and the base.

[0576] When the guide 161 is threadedly connected to the base 2, the guide 161 is easy to install and remove; when the guide 161 is threadedly connected to the base 2 and the guide 161 is in surface contact with the track 162, the "surface contact between the guide 161 and the track 162" is used to prevent the guide 161 from rotating relative to the base 2 during the sliding process.

[0577] When the guide 161 comes into contact with the track 162, in order to ensure the reliability of the threaded connection between the guide 161 and the base 2, the guide 161 and the track 162 are fitted with a clearance.

[0578] In this application, the guide 161 has an arc surface that contacts the track 162. The connecting force between the guide 161 and the base 2 is greater than the sliding friction generated during the sliding of the guide 161 along the track 162. When the guide 161 is threadedly connected to the base 2, the "connecting force between the guide 161 and the base 2" is the threaded connection force between the guide 161 and the base 2, that is, the threaded connection force between the guide 161 and the base 2 is greater than the sliding friction generated during the sliding of the guide 161 along the track 162. This structure prevents the guide 161 from rotating relative to the base 2 during the sliding of the guide 161 along the track 162; "rotation of the guide 161 relative to the base 2" would cause the guide 161 to separate from the base 2.

[0579] The annular gasket 1614 in "the annular gasket 1614 sandwiched between the guide 161 and the base 2" is used to further increase the connection strength between the guide 161 and the base 2.

[0580] As shown in Figure 22, the base 1 is provided with an installation port 120, and the base 1 is provided with an extension ring 121 around the installation port 120. The hardness of the track 162 is less than the hardness of the extension ring 121. The track 162 is inserted into the extension ring 121 through the installation port 120. When the track 162 is inserted into the extension ring 121, the track 162 penetrates the extension ring 121.

[0581] The extension ring 121 increases the contact area between the base 1 and the track 162, thereby improving the connection strength between the track 162 and the base 1. Furthermore, since the hardness of the track 162 is lower than that of the extension ring 121, the track 162 can deform during installation, reducing the difficulty of installing the track 162.

[0582] As shown in Figure 22, the guide 161 includes a slide rod 1613, the hardness of the annular gasket 1614 is less than the hardness of the extension ring 121, and the slide rod 1613 passes through the track 162 and the annular gasket 1614 in sequence and is fixedly connected to the base 2.

[0583] When the slide bar 1613 passes through the track 162 and the annular gasket 1614 in sequence and is fixedly connected to the base 2, the annular gasket 1614 can abut against the track 162.

[0584] The advantages of the annular gasket 1614 include: 1. The annular gasket 1614 increases the connection strength between the slide rod 1613 and the base 2; 2. When the slide rod 1613 passes through the track 162 and the annular gasket 1614 in sequence and is fixedly connected to the base 2, the annular gasket 1614 prevents the track 162 from directly contacting the base 2, thus avoiding scratches on the base 2; 3. The annular gasket 1614 has low replacement cost; 4. The annular gasket 1614 and the track 162 are plastic parts, which can reduce the assembly accuracy requirements between the base 2 and the base 1; even if the annular gasket 1614 and the track 162 are not plastic parts, since "the hardness of the track 162 < the hardness of the extension ring 121" and "the hardness of the annular gasket 1614 < the hardness of the extension ring 121", the annular gasket 1614 and the track 162 can still reduce the assembly accuracy requirements between the base 2 and the base 1.

[0585] Preferably, the slide rod 1613 is threadedly connected to the base 2; and / or, the outer periphery of the track 162 is provided with several outwardly protruding ribs, and the track 162 is inserted into the base 1. When the track 162 is inserted into the base 1, the track 162 abuts against the base 1 through the ribs. The threaded connection between the slide rod 1613 and the base 2 facilitates the disassembly and replacement of the slide rod 1613. The presence of several ribs on the outer periphery of the track 162 effectively solves the problem of the track 162 being unable to be properly assembled due to its varying material thickness.

[0586] More preferably, when the slide rod 1613 is threadedly connected to the base 2, the threaded connection between the slide rod 1613 and the base 2 is filled with adhesive; and / or, when the slide rod 1613 is threadedly connected to the base 2, the slide rod 1613 is in contact with the surface of the track 162.

[0587] The adhesive is used to further increase the connection strength between the slide rod 1613 and the base 2, preventing the slide rod 1613 from loosening after rotating relative to the base 2. The contact between the slide rod 1613 and the track 162 surface effectively prevents the slide rod 1613 from rotating relative to the base 2.

[0588] As shown in Figure 23, the base 1 is provided with an installation port 120, and the base 1 is provided with an extension ring 121 around the installation port 120. The hardness of the track 162 is less than the hardness of the extension ring 121. The track 162 is inserted into the extension ring 121 through the installation port 120. When the track 162 is inserted into the extension ring 121, the track 162 does not penetrate the extension ring 121.

[0589] Since the track 162 does not penetrate the extension ring 121, the extension ring 121 located within the track 162 will not collide with the base 2; that is, during the back-and-forth movement of the base 2, this structure effectively reduces the probability of the base 2 colliding with the track 162, thereby reducing the probability of the track 162 displacing relative to the base 1.

[0590] As shown in Figure 23, the guide 161 includes a slide rod 1613 and an annular gasket 1614. The hardness of the annular gasket 1614 is less than the hardness of the extension ring 121. The slide rod 1613 passes through the track 162 and the annular gasket 1614 in sequence and is fixedly connected to the base 2.

[0591] When the slide bar 1613 passes through the track 162 and the annular gasket 1614 in sequence and is fixedly connected to the base 2, the annular gasket 1614 can abut against the extension ring 121.

[0592] The annular gasket 1614 is used to protect the base 2 and prevent the base 2 from being scratched by the extension ring 121.

[0593] Preferably, the slide rod 1613 is threadedly connected to the base 2; and / or, the outer periphery of the track 162 is provided with a plurality of outwardly protruding ribs, the track 162 is inserted into the base 1, and when the track 162 is inserted into the base 1, the track 162 abuts against the base 1 through the ribs.

[0594] Preferably, in this application, the track 162 is snap-fitted to the base 1; and / or, the track 162 is connected to the base 1 by a third fastener, which can be one of a screw, bolt, or pin. This structure facilitates the assembly and disassembly of the track.

[0595] Of course, the first and second fasteners can also be one of screws, bolts, or pins.

[0596] In this application, when the annular gasket 1614 is held between the guide 161 and the base 2, the radial width of the annular gasket 1614 is greater than the width of the guide 161; during the process of the mechanical extension structure 100 changing from a sitting position to a lying position, the annular gasket 1614 can slide along the track 162 or the base 1.

[0597] "Radial width of annular gasket 1614" refers to the vertical length of annular gasket 1614, and "width of guide 161" refers to the vertical length of guide 161. As shown in Figures 22, 23 and 26, the vertical length of annular gasket 1614 is greater than the vertical length of guide 161.

[0598] The radial width of the annular gasket 1614 is greater than the width of the guide 161, allowing the annular gasket 1614 to slide along the track 162 or the base 1. This structure effectively prevents the base from being scratched by the base or track. Since the base surface is usually coated, the coating increases the base's corrosion resistance and oxidation resistance. Therefore, the ability of the annular gasket to slide along the track or base effectively improves the service life of the base.

[0599] In this application, one connection method for the guide 161 in the description of "guide 161 being fixedly connected to base 2 and detachably disposed on base 2" is a threaded connection between guide 161 and base 2. Another connection method for guide 161 in the description of "guide 161 being fixedly connected to base 2 and detachably disposed on base 2" is a fixed connection between guide 161 and base 2 via at least two first fasteners. The two first fasteners further increase the connection strength between guide 161 and base 2 and reduce the probability of guide 161 moving relative to base 2, thereby improving the operational reliability of the mechanical extension structure 100.

[0600] When the guide 161 and the base 2 are fixedly connected by at least two first fasteners, at least one first fastener can slide along the guide 161 and / or the base 2 to change the spacing between two adjacent first fasteners. To allow the first fastener to slide along the guide 161, a horizontal guide groove is provided on the guide 161; to allow the first fastener to slide along the base 2, a horizontal guide groove is provided on the base 2. By changing the spacing between two adjacent first fasteners, the connection strength between the guide 161 and the base 2 is adjusted, allowing guides 161 of different specifications to be adapted to bases 2 of different specifications; that is, increasing the versatility of the guide 161 and the base 2.

[0601] In this application, the outer contour of the guide 161 can be circular or conical; when the outer contour of the guide 161 is conical, the guide 161 includes a slide rod, the slide rod has a first tapered section, the diameter of the first tapered section gradually decreases along the axial direction of the slide rod, and the first tapered section can abut against the track 162; and / or, the track 162 has a second tapered section, the second tapered section is inclined along the axial direction of the guide 161, and the second tapered section can abut against the guide 161;

[0602] When the guide 161 has a first tapered section and the track 162 has a second tapered section, the first tapered section abuts against the second tapered section. The first and second tapered sections are used to increase the stability of the slide bar during sliding and to limit the position of the base 2 relative to the base 1 in the axial direction of the slide bar.

[0603] The seat unit includes a backrest structure 200, a seat cushion structure 300, and a mechanical extension structure 100 as described in this embodiment. The backrest assembly 4 is disposed on the backrest structure 200, and the seat cushion structure 300 is disposed above the base 2.

[0604] When the mechanical extension structure 100 is in a seated position, the backrest assembly 4 compresses the seat cushion structure 300, which undergoes elastic deformation and then indents inward.

[0605] When the mechanical extension structure 100 is in a seated position and the backrest assembly 4 presses against the seat cushion structure 300, the backrest assembly 4 will prevent the user's hand from reaching between the backrest assembly 4 and the base 2 from above. This structure effectively reduces the probability of the user's hand being pinched by the seat unit.

[0606] In this application, when the mechanical extension structure 100 is in a reclining position, the backrest assembly 4 presses against the seat cushion structure 300, and the seat cushion structure 300 undergoes elastic deformation and then indents inward; or, when the mechanical extension structure 100 is in a reclining position, there is a gap between the backrest assembly 4 and the seat cushion structure 300.

[0607] When the mechanical extension structure 100 is in a reclining position and the backrest assembly 4 presses against the seat cushion structure 300, the backrest assembly 4 can prevent the user's hand from reaching between the backrest assembly 4 and the base 2 from top to bottom in the reclining position; and when the mechanical extension structure 100 is in a reclining position and there is a gap between the backrest assembly 4 and the seat cushion structure 300, the gap can reduce the probability that the backrest assembly 4 will puncture the seat cushion structure 300 in the sitting position.

[0608] Preferably, when the mechanical extension structure 100 is in a seated position, the backrest front support 42 and the seat cushion structure 300 are in a clearance fit; and / or, when the mechanical extension structure 100 is in a reclining position, the backrest front support 42 and the seat cushion structure 300 are in a clearance fit. This structure prevents the backrest front support 42 from scratching the seat cushion decorative cover (which may be made of leather or technical fabric) on the seat cushion structure 300. When one end of the linkage bracket 134 is rotatably connected to the side wall of the base 2, and the backrest front support 42 and the seat cushion structure 300 are in a clearance fit, the linkage bracket 134 blocks the backrest front support 42, as shown in Figures 18 and 21. Therefore, unless the user intentionally inserts their hand between the linkage bracket 134 and the backrest front support 42, their hand will not be trapped between the backrest front support 42 and the base 2.

[0609] This application includes two types of seat cushion structures 300: 1. A seat cushion structure 300 includes a seat cushion elastic element, a seat cushion filling, and a seat cushion decorative cover. The seat cushion filling is disposed inside the seat cushion decorative cover, and the seat cushion decorative cover is disposed on a base 2. The seat cushion elastic element is disposed on the base 2 to provide elastic support for the seat cushion decorative cover. 2. A seat cushion structure 300 includes a seat cushion frame, a seat cushion elastic element, a seat cushion filling, and a seat cushion decorative cover. The seat cushion filling is disposed inside the seat cushion decorative cover, and the seat cushion decorative cover is disposed on the seat cushion frame, which is disposed on the base 2. The seat cushion elastic element is disposed on the seat cushion frame to provide elastic support for the seat cushion decorative cover.

[0610] Preferably, the seat cushion decorative cover is provided with a second sealing structure, and the second sealing structure is provided with a second zipper. The second zipper is used to open or close the second sealing structure. After the second zipper opens the second sealing structure, the seat cushion filling can enter the seat cushion decorative cover from the second sealing structure.

[0611] Preferably, when the seat cushion decorative cover is located on the base 2, the seat cushion decorative cover is hung on the base 2; when the seat cushion decorative cover is located on the seat cushion frame, the seat cushion decorative cover is hung on the seat cushion frame.

[0612] Preferably, the base 2 includes four connecting rods, which are connected end to end to form a quadrilateral. At least one connecting rod includes a first angle iron, a second angle iron, and a mounting plate. The first angle iron and the second angle iron are L-shaped. The first angle iron includes a first horizontal plate and a first vertical plate. The second angle iron includes a second horizontal plate and a second vertical plate. The first horizontal plate is fixedly connected to the second vertical plate, and the second horizontal plate is fixedly connected to the first vertical plate.

[0613] The height of the first vertical plate is greater than the height of the second vertical plate. When the first horizontal plate is fixedly connected to the second vertical plate and the second horizontal plate is fixedly connected to the first vertical plate, the inner side of the first vertical plate and the outer side of the second vertical plate are fixedly connected to the mounting plate.

[0614] The mechanical extension structure also includes a first drive device 15, and the mounting plate is directly or indirectly rotatably connected to the first drive device 15.

[0615] When the inner side of the first vertical plate and the outer side of the second vertical plate are fixedly connected to the mounting plate, the deformation resistance of the connecting rod will be improved; and at least one connecting rod including the first angle iron and the second angle iron effectively improves the applicable scenarios of the connecting rod.

[0616] As shown in Figures 19 and 21, the first driving device 15 includes a first driver 151 and a first driving rod 152 disposed on the first driver 151. The first driver 151 is rotatably connected to the rear of the base 2, and the first driving rod 152 is rotatably connected to the swing plate 1531.

[0617] The connecting structure 153 also includes a connecting rod, which is rotatably connected to the base 2. The swing plate 1531 and the leg assembly 5 are respectively fixedly connected to the connecting rod 153.

[0618] As shown in Figures 15 and 19, the first driving device 15 is movably disposed on the base 2; of course, the first driving device 15 of this application can also be movably disposed on the base 1.

[0619] As shown in Figures 15 and 19, the first driving device 15 includes:

[0620] The first driver 151 is movably disposed on the base 2 or the base 1;

[0621] The first drive rod 152 is movably disposed on the first driver 151;

[0622] The connecting structure 153 is fixedly connected to the leg assembly 5 and rotatably connected to the base 2. The connecting structure 153 includes a swing plate 1531 rotatably connected to the first drive rod 152. During the process of the mechanical extension structure 100 changing between a sitting position and a lying position, the first drive rod 152 drives the connecting structure 153 to rotate relative to the base 2 through the swing plate 1531.

[0623] In related technologies, the mechanical extension structure is provided with two sets of leg components, which are connected by a connecting structure. The connecting structure is rotatably connected to the first drive rod on the first driver. However, the existing connecting structure is not rotatably connected to the base. That is to say, during the process of the leg components extending in front of the base (or the leg components retracting below the base), the connecting structure is suspended in the air throughout. At this time, the force required for the leg components to move relative to the base is directly provided by the connecting structure.

[0624] The connecting structure 153 is fixed to the leg assembly 5 (i.e., the leg assembly 5 is fixedly connected to the connecting rod). During the process of the mechanical extension structure 100 changing between the sitting position and the lying position, the first drive rod 152 drives the connecting structure 153 to rotate relative to the base 2 through the swing plate 1531, so that the connecting structure 153 drives the leg assembly 5 to extend in front of the base 2 or retract below the base 2.

[0625] In this application, since the connecting mechanism 153 is rotatably connected to the base 2, the base 2 provides support for the connecting mechanism 153 throughout the process of the leg assembly 5 extending in front of the base 2 (or the leg assembly 5 retracting below the base 2). This means that during the process of the leg assembly 5 extending in front of the base 2 (or the leg assembly 5 retracting below the base 2), the base 2 can reduce at least part of the torque required for the connecting mechanism 153 to drive the leg assembly 5.

[0626] As shown in Figures 15 and 19, the first driving device 15 is located at an eccentric position on the base 2. The structure of "the connecting mechanism 153 being rotatably connected to the base 2" provides an eccentric basis for "the first driving rod being located at an eccentric position on the connecting structure".

[0627] In related technologies, the first drive rod of the seat unit is located in the middle of the base; a serpentine spring is provided on the base to support the seat cushion structure, and at least part of the seat cushion structure is provided above the serpentine spring. When a user sits on the seat cushion structure, the seat cushion structure transfers the user's weight to the serpentine spring, causing the serpentine spring to elastically deform. However, users have found that when the first drive rod of the seat unit is located in the middle of the base, the elastically deformed serpentine spring may come into contact with the first drive rod. Therefore, this application places the first drive device 15 at an eccentric position on the base 2 to further reduce the probability of the serpentine spring contacting the first drive rod 152.

[0628] In this application, since the connecting rod is rotatably connected to the base 2, the base 2 provides support for the connecting rod throughout the entire process of the leg assembly 5 extending in front of the base 2 (or retracting below the base 2). This means that during the process of the leg assembly 5 extending in front of the base 2 (or retracting below the base 2), the base 2 can reduce at least part of the torque required for the connecting rod to drive the leg assembly 5. This structure is used to solve the problem of vibration that may occur when the connecting rod drives the leg assembly 5.

[0629] Preferably, a bearing is provided between the connecting rod and the base 2; and / or, a lubricant is provided at the rotatable connection between the connecting rod and the base 2. Both the bearing and the lubricant are used to reduce the frictional resistance encountered by the connecting rod during its rotation relative to the base 2.

[0630] As shown in Figure 24, the base 2 is provided with at least one support block 114, and at least one connecting rod is located below the support block 114. The base 2 can abut against the connecting rod through the support block 114; and / or, at least part of the support block 114 is located between the side wall of the base 2 and the side wall of the connecting rod 153.

[0631] After the base 2 is impacted by an external force, the base 2 can transfer part of the impact force to the connecting rod through the support block 114 to improve the base 2's resistance to deformation. If the connecting rod is located below the support block 114, it can absorb the impact force from above the base 2. If the connecting rod is located on the side wall of the base 2, it can absorb the impact force from the side of the base 2. This structure is used to reduce the deformation amplitude of the base 2 after being impacted by an external force.

[0632] In this application, the connecting structure 153 may include a connecting rod, and the two sets of leg components 5 are connected by the connecting rod, as shown in Figures 15 and 21; in this application, the connecting structure 153 may also include two connecting rods, each connecting rod connecting a set of leg components 5, and each connecting rod being fixedly connected to the swing plate 1531.

[0633] In this application, the hardness of the support block 114 is less than the hardness of the base 2, the hardness of the support block 114 is less than the hardness of the connecting rod, and the distance between the support block 114 and the connecting rod is less than the vertical length of the connecting rod. Since the connecting rod in this application is circular, the vertical length of the connecting rod is the diameter of the connecting rod.

[0634] Preferably, the base 2 is made of metal, the support block 114 is made of plastic, and the connecting rod is made of metal.

[0635] When the hardness of the support block 114 is less than the hardness of the base 2, and when the hardness of the support block 114 is less than the hardness of the connecting rod, the support block 114 can absorb part of the impact force from external objects through its own deformation, thereby further reducing the deformation amplitude of the base 2 after being impacted by external forces. When the hardness of the support block 114 is less than the hardness of the base 2, and when the hardness of the support block 114 is less than the hardness of the connecting rod, after being impacted by external forces, the deformation of the support block 114 precedes the deformation of the connecting rod, and the deformation of the support block 114 precedes the deformation of the base 2.

[0636] As shown in Figure 24, the connecting rod is a circular connecting rod, and the support block 114 is provided with an arc-shaped groove corresponding to the connecting rod, with at least part of the connecting rod inserted into the arc-shaped groove. The arc-shaped groove is used to define the position of the connecting rod on the support block 114 and to increase the contact area between the connecting rod and the support block 114; this structure prevents the support block 114 from sliding along the connecting rod and separating from the connecting rod after the base 2 is impacted by external force; that is, it ensures the reliability of the operation of the support block 114.

[0637] As shown in Figure 24, the base 2 has flanges 116 on both sides, and the flanges 116 on both sides and the base 2 form a receiving groove 117, with at least part of the support block 114 located within the receiving groove 117. This structure ensures the deformation resistance of the base 2 while reducing its thickness.

[0638] As shown in Figure 21, a hook 112 is provided on the front side of the base 2 and another hook 112 is provided on the rear side of the base 2. However, in this application, it is preferred that the hook 112 is provided on the front side of the base 2 and a hooking channel is provided on the rear side of the base 2. The mechanical extension structure 100 also includes a seat cushion elastic member, one end of which is provided on the hook 112 and the other end of which is provided on the hooking channel.

[0639] The mounting channel is open at both ends and circumferentially closed, while the hook 112 is open at both ends and circumferentially open. The circumferentially closed mounting channel can increase the deformation resistance of the rear of the base 2, especially since the mounting channel is located at the rear of the base 2, and the rear of the base 2 is rotatably connected to the first driver 151. When the mounting channel is set at the rear of the base 2, in order to reduce the installation difficulty of the seat cushion elastic element, the hook 112 is set at the front of the base 2.

[0640] In this application, the backrest structure 200 includes a backrest frame 1001, a backrest filler 1004, and a backrest decorative cover 1005. The backrest filler 1004 is disposed on the backrest decorative cover 1005, and the backrest decorative cover 1005 is disposed on the backrest frame 1001. The front of the backrest filler 1004 is provided with an inwardly recessed decorative groove, and the backrest decorative cover 1005 is detachably inserted into the decorative groove.

[0641] In related technologies, the backrest decorative cover uses stitching to create an inwardly recessed decorative seam on the front of the backrest structure. However, the stitching method increases the assembly time required for the backrest structure.

[0642] In this application, an inwardly recessed decorative groove is directly provided on the front of the backrest filling 1004, and the backrest decorative cover 1005 is inserted into the decorative groove, thus directly forming the decorative seam required for the backrest structure 200.

[0643] Preferably, in this application, the backrest decorative cover 1005 and the decorative groove are fixedly connected by Velcro. The Velcro includes two parts: a hook and a loop. The loop is glued to the hook so that the backrest decorative cover 1005 can be detachably mounted on the backrest frame.

[0644] And / or, the decorative groove includes inclined groove walls, and the cross-sectional area of ​​the groove opening is less than the cross-sectional area of ​​the groove bottom.

[0645] When the backrest decorative cover 1005 is fixedly connected to the decorative groove by Velcro, and the backrest decorative cover 1005 is detachably mounted on the backrest frame 1001, the backrest decorative cover 1005 can be cleaned, disassembled, and installed without the aid of other tools.

[0646] When the decorative groove includes an inclined groove wall and the cross-sectional area of ​​the groove opening is less than the cross-sectional area of ​​the groove bottom, the connection strength between the backrest decorative cover 1005 and the decorative groove will be increased to prevent the backrest decorative cover 1005 from easily separating from the backrest filling 1004 under the friction of the user's back.

[0647] In this application, the backrest structure 200 also includes a backrest elastic element, which is disposed on the backrest frame 1001 and is used to provide elastic support for the backrest decorative cover 1005.

[0648] Preferably, the backrest cover 1005 has a second sealing structure with a second zipper. The second zipper is used to open or close the second sealing structure. After the second zipper opens the second sealing structure, the backrest filling can enter the backrest cover through the second sealing structure. This structure, combined with Velcro, allows the backrest filling to be removed from the backrest cover without the need for any tools.

[0649] In this application, four preferred structures for the backrest assembly are:

[0650] The first type of backrest assembly includes a backrest panel, a front backrest bracket, a rear backrest bracket, and a backrest drive rod. The backrest panel is located on the backrest structure. One end of the front backrest bracket is rotatably connected to the backrest panel, and the other end of the front backrest bracket is rotatably connected to the base. One end of the rear backrest bracket is rotatably connected to the backrest panel, and the rear backrest bracket is rotatably connected to the base. One end of the backrest drive rod is rotatably connected to the other end of the rear backrest bracket, and the other end of the backrest drive rod is rotatably connected to the base.

[0651] The second structure includes a backrest panel, a front backrest bracket, a rear backrest bracket, and a backrest drive rod. The backrest panel is located on the backrest structure. One end of the front backrest bracket is rotatably connected to the backrest panel, and the other end of the front backrest bracket is fixedly connected to the base. One end of the rear backrest bracket is rotatably connected to the backrest panel, and the rear backrest bracket is rotatably connected to the base. One end of the backrest drive rod is rotatably connected to the other end of the rear backrest bracket, and the other end of the backrest drive rod is rotatably connected to the base.

[0652] The third type of backrest assembly includes a backrest panel, a front backrest bracket, a rear backrest bracket, a backrest connecting bracket, and a backrest drive rod. The backrest panel is located on the backrest structure. One end of the front backrest bracket is rotatably connected to the backrest panel, and the other end of the front backrest bracket is rotatably connected to the base. One end of the rear backrest bracket is rotatably connected to the backrest panel, and the other end of the rear backrest bracket is rotatably connected to one end of the backrest connecting bracket. The backrest connecting bracket is also rotatably connected to the base. One end of the backrest drive rod is rotatably connected to the other end of the backrest connecting bracket, and the other end of the backrest drive rod is rotatably connected to the base.

[0653] The fourth type of backrest assembly includes a backrest panel, a front backrest bracket, and a rear backrest bracket. The backrest panel is located on the backrest structure. One end of the front backrest bracket is rotatably connected to the backrest panel, and the other end of the front backrest bracket is rotatably connected to the base. One end of the rear backrest bracket is rotatably connected to the backrest panel, and the rear backrest bracket is rotatably connected to the base.

[0654] The fifth type of backrest assembly 4 is shown in Figures 15 and 17. The backrest assembly 4 includes a backrest panel 41, a front backrest bracket 42, a rear backrest bracket 43, and a linkage bracket 134. The backrest panel 41 is disposed on the backrest structure 200. One end of the front backrest bracket 42 and one end of the rear backrest bracket 43 are rotatably connected to the backrest panel 41, and the other end of the front backrest bracket 42 and the other end of the rear backrest bracket 43 are rotatably connected to the base 1.

[0655] One end of the linkage bracket 134 is rotatably connected to the base 2, and the other end of the linkage bracket 134 is rotatably connected to the back support 43, as shown in Figure 17.

[0656] The first type of backrest assembly, the second type of backrest assembly, the third type of backrest assembly, and the fourth type of backrest assembly: During the process of changing between a sitting position and a reclining position, the mechanical extension structure 100 can compress the side wall of the seat cushion structure, and the seat cushion structure will deform elastically and then be concave inward.

[0657] In this application, during the transition between a sitting and reclining position, the front support of the backrest can separate from the side wall of the seat cushion structure; when the mechanical extension structure is in the sitting position, the front support of the backrest separates from the side wall of the seat cushion structure. This structure reduces the probability of the front support of the backrest puncturing the seat cushion structure.

[0658] In this application, the backrest structure 200 and the seat cushion structure 300 are related technologies, therefore, the backrest structure and the seat cushion structure are not shown in the detailed drawings.

[0659] In this application, the backrest structure 200 includes a backrest frame 1001, a backrest filler 1004, and a backrest decorative cover 1005. The backrest filler 1004 is disposed inside the backrest decorative cover 1005, and the backrest decorative cover 1005 is disposed in the backrest frame 1001.

[0660] As shown in Figure 17, the support rod 18 is located below the base 1 to support the seat unit. The vertical length of the support rod 18 is L2, and L2 is greater than or equal to 8cm.

[0661] As shown in Figures 19 and 21, the mechanical extension structure 100 also includes two sets of swing mechanisms 7. A set of leg components 5, base 2 and base 1 are movably connected to a set of swing mechanisms 7 respectively. A support rod 18 is provided below the base 1.

[0662] When the mechanical extension structure 100 is in a seated position, the distance between the lowest point of the swing mechanism 7 and the lower end face of the support rod 18 is ≥8cm; and / or, when the mechanical extension structure 100 is in a reclining position, the distance between the lowest point of the swing mechanism 7 and the lower end face of the support rod 18 is ≥8cm.

[0663] During the transition between a sitting and reclining position, at least a portion of the swing mechanism 7 can move below the base 1. This structure increases the range of motion of the base 2 relative to the base 1 within a limited space (especially within a limited front-to-back distance) by increasing the length of the swing mechanism 7.

[0664] Because "the first driver 151 is rotatably connected to the rear of the base 2, and the first drive rod 152 is rotatably connected to the swing plate 1531", when a set of leg assemblies 5, the base 2, and the base 1 are respectively movably connected to a set of swing mechanisms 7, the leg assembly 5 can drive the base 2 to slide relative to the base 1 through the swing mechanism 7. Of course, in this application, when the first driver 151 is rotatably connected to the base 1, the swing mechanism 7 is not required.

[0665] In related technologies, when a user sits or lies on top of a seat unit, some seat units may be too low for the robot vacuum to properly enter under the seat unit and clean the floor below it due to insufficient height of the support rod or mechanical extension structure.

[0666] The height of a robotic vacuum cleaner is around 8cm. When the distance between the lowest point of the swing mechanism and the lower end of the support rod is ≥8cm, most robotic vacuum cleaners can directly enter under the seat unit.

[0667] As shown in Figures 19 and 21, the swing mechanism 7 includes a ninth link 171, a tenth link 172, and an eleventh link 173. One end of the ninth link 171 is rotatably connected to the base 1, one end of the eleventh link 173 is rotatably connected to the leg assembly 5, the other end of the ninth link 171 is rotatably connected to one end of the tenth link 172, and the other end of the eleventh link 173 is rotatably connected to the other end of the tenth link 172.

[0668] The tenth link 172 is rotatably connected to the base 2, wherein the eccentric position of the tenth link 172 is rotatably connected to the base 2.

[0669] The eccentric position of the tenth link 172 is rotatably connected to the base 2. This is used in conjunction with the first drive device 15 to adjust the sliding speed of the base 2 relative to the base 1. This is to match the adjustment speed of the seat unit for users of different ages. The adjustment speed is the speed at which the mechanical extension structure 100 switches back and forth between the sitting position and the reclining position.

[0670] Of course, in this application, in order to avoid the three-link structure of the swing mechanism 7, the swing mechanism 7 can also have four or more links. For example, the first link can be replaced with at least two links, the second link can be replaced with at least two links, and the third link can be replaced with at least two links. The swing mechanism and the base, base, and leg assembly can also rotate with slight sliding engagement within the limiting groove.

[0671] Preferably, the distance between the rotatable connection point of the tenth link 172 and the base 2 and the rotatable connection point of the ninth link 171 and the tenth link 172 is greater than the distance between the rotatable connection point of the tenth link 172 and the base 2 and the rotatable connection point of the eleventh link 173 and the tenth link 172. The distance between the rotatable connection points of the tenth link 172 and base 2 and the ninth link 171 and tenth link 172 is greater than the distance between the rotatable connection points of the tenth link 172 and base 2 and the eleventh link 173 and tenth link 172. This distance is used to adjust the extension difficulty of the leg assembly 5. When the distance between the rotatable connection points of the tenth link 172 and base 2 and the ninth link 171 and tenth link 172 is greater than the distance between the rotatable connection points of the tenth link 172 and base 2 and the eleventh link 173 and tenth link 172, the movement speed of the leg assembly 5 during the transition from a sitting to a lying position in the mechanical extension structure 100 will slow down using the lever principle. This structure allows users to easily adjust the seat unit to their preferred angle.

[0672] Preferably, the base 2 has a groove that is recessed from the outside to the inside, and the leg assembly 5 is rotatably connected to the base 2 located in the groove by a second fastener;

[0673] At least part of the second fastener is located within the groove.

[0674] The groove is used to reduce the probability that the second fastener will collide with foreign objects during the transportation of the seat unit.

[0675] Preferably, a first elastic element is provided between the base 2 and the base 1; and / or, a second elastic element is provided between the base 2 and the leg assembly 5.

[0676] The first elastic element is used to increase the stability of the base 2 relative to the base 1 during movement, and the second elastic element is used to increase the stability of the leg assembly 5 relative to the base 2 during movement.

[0677] In this application, the first driving device 15 can be a different driving source.

[0678] The first type of drive source is a motor in the first drive device 15; and / or, during the process of the mechanical extension structure 100 changing from a sitting position to a lying position, the first guide member moves only along the second guide surface 16222 of the first track 1601, and the second guide member moves only along the second guide surface 16222 of the inclined section 168 and the second guide surface 16222 of the straight section 169. The motor provides a power source for the mechanical extension structure; "the first guide member moves only along the second guide surface 16222 of the first track 1601, and the second guide member moves only along the second guide surface 16222 of the inclined section 168 and the second guide surface 16222 of the straight section 169" means that the second guide surface 16222 of the first track 1601 provides support for the first guide member, and the second guide surface 16222 of the inclined section 168 and the second guide surface 16222 of the straight section 169 provide support for the second guide member. This structure effectively improves the smoothness of the mechanical extension structure 100 changing from a sitting position to a lying position.

[0679] The second guide is fixedly connected to the base 2 and is detachably mounted on the base 2. During the transition of the mechanical extension structure 100 from a sitting position to a lying position, the second guide can slide along the second guide surface 16222 of the inclined section 168, and also along the second guide surface 16222 of the straight section 169. The fixed connection between the second guide and the base 2 increases the smoothness of the movement of the second guide on the inclined section 168 (or the straight section 169). In this application, the second guide can also be rotatably connected to the base 2 and is detachably mounted on the base 2. During the transition of the mechanical extension structure 100 from a sitting position to a lying position, the second guide can roll along the second guide surface 16222 of the inclined section 168, and also along the second guide surface 16222 of the straight section 169. The rotatable connection between the second guide and the base 2 further reduces the frictional force of the second guide moving along the inclined section 168.

[0680] The second type of drive source is a cylinder in the first drive device 15. During the process of the mechanical extension structure 100 changing from a lying position to a sitting position, the cylinder retracts to provide assistance for the retraction of the leg assembly 5; and / or, during the process of the mechanical extension structure 100 changing from a lying position to a sitting position, the first guide moves only along the first guide surface 16221 of the first track 1601, and the second guide moves only along the first guide surface 16221 of the inclined section 168 and the first guide surface 16221 of the straight section 169. The cylinder provides auxiliary power to the m...

Claims

Mechanical extension structures, including: Base; The base is located above the pedestal; Two sets of swing mechanisms, with the base and the pedestal movably connected via the swing mechanisms; Linkage rod, each set of swing mechanisms is fixedly connected to the end of the linkage rod; Two backrest components are located at the base and behind the pedestal; Two sets of leg components are located at the front of the base; The first drive mechanism is used to drive the leg components to move; The mechanical extension structure has a sitting position, a TV position, and a reclining position. During the transition from the sitting position to the reclining position, the first drive mechanism drives the base forward through the leg assembly, so that the leg assembly extends in front of the base and the backrest assembly tilts backward relative to the base. During the transition from the reclining position to the sitting position, the first drive mechanism drives the base backward through the leg assembly, so that the leg assembly retracts under the base and the backrest assembly returns to its original position relative to the base. The feature is that the base is provided with an installation surface, and each backrest assembly includes a backrest plate and a front backrest bracket, with the backrest plate and the base respectively rotatably connected to the front backrest bracket; During the transition from a seated position to a TV position, the backrest and the front backrest support move forward, while the front backrest support remains stationary relative to the base. When the mechanical extension structure is in the TV position, the angle between the centerline of the front backrest support and the mounting surface is greater than 90°. During the transition from a TV position to a reclining position, the backrest moves forward and the front backrest support rotates relative to the base. When the mechanical extension structure is in the reclining position, the angle between the centerline of the front backrest support and the mounting surface is less than 90°. The mechanical extension structure according to claim 1 is characterized in that, The backrest panel has an installation position for mounting the backrest structure and a transition position for rotatably connecting with the front support of the backrest. The angle between the line connecting the midpoint of the installation position and the midpoint of the transition position and the installation surface is α. The angle α of the mechanical extension structure in the TV position is greater than the angle α of the mechanical extension structure in the reclining position. The mechanical extension structure according to claim 2 is characterized in that, The base is provided with a first limiting rod. When the mechanical extension structure is in the sitting position, TV position, and reclining position, the first limiting rod abuts against the front support of the backrest. During the process of the mechanical extension structure changing from the sitting position to the TV position, the first limiting rod abuts against the front support of the backrest. During the process of the mechanical extension structure changing from the TV position to the reclining position, the first limiting rod does not abut against the front support of the backrest. The mechanical extension structure according to claim 3 is characterized in that, The length of the front backrest bracket above the rotatable connection between the front backrest bracket and the base is greater than the length of the front backrest bracket below the rotatable connection between the front backrest bracket and the base; when the mechanical extension structure is in the TV position, the transition position is located behind the first limit rod, the first limit rod abuts against the front backrest bracket and prevents the front backrest bracket from moving downward. When the mechanical extension structure is in the reclining position, the transition position is located in front of the first limiting rod, the first limiting rod abuts against the front support of the backrest and prevents the front support of the backrest from moving upward. The mechanical extension structure according to any one of claims 1-4 is characterized in that, Each set of swing mechanisms includes: The front support plate is rotatably connected to the base; The rear support plate is rotatably connected to the base; The inner swing assembly, base, backrest assembly, leg assembly, front support plate and rear support plate are movably connected to the inner swing assembly respectively; The external swing assembly is movably connected to the leg assembly, and the linkage rod is fixedly connected to the external swing assembly; The backrest assembly also includes a backrest support bracket rotatably connected to the backrest panel, and the inner swing assembly includes a rear swing plate, with the base, rear support plate, and backrest support bracket rotatably connected to the rear swing plate respectively. The mechanical extension structure according to claim 5 is characterized in that, The backrest assembly also includes a backrest connecting bracket, one end of which is rotatably connected to the front backrest bracket, and the other end of which is rotatably connected to the rear swing plate. In the process of changing from a sitting position to a TV position, the front support of the backrest remains in a fixed position relative to the backrest connecting support; in the process of changing from a TV position to a reclining position, the front support of the backrest rotates relative to the backrest connecting support. The mechanical extension structure according to claim 5 is characterized in that, The backrest is equipped with a second limiting rod. When the mechanical extension structure is in the sitting position and the TV position, the second limiting rod abuts against the backrest support. During the process of the mechanical extension structure changing from the sitting position to the TV position, the second limiting rod abuts against the backrest support. The mechanical extension structure according to claim 7 is characterized in that, The front support of the backrest is equipped with a third limiting rod. When the mechanical extension structure is in the TV position, the backrest panel does not abut against the third limiting rod. The base is equipped with a first limiting rod. When the mechanical extension structure is in the reclining position, the back support of the backrest does not abut against the second limiting rod, the backrest panel abuts against the third limiting rod, and the front support of the backrest abuts against the first limiting rod. During the process of the mechanical extension structure changing from the TV position to the lying position, the backrest does not abut against the third limiting rod, the front backrest bracket does not abut against the first limiting rod, and the backrest bracket does not abut against the second limiting rod. The mechanical extension structure according to claim 6 is characterized in that, The rotatable connection between the rear support plate and the rear swing plate is located above the rotatable connection between the backrest connecting bracket and the rear swing plate, and the rotatable connection between the base and the rear swing plate is located below the rotatable connection between the backrest connecting bracket and the rear swing plate. The rear swing plate is equipped with a fourth limiting rod. When the mechanical extension structure is in the sitting position, when the mechanical extension structure is in the TV position, and during the process of the mechanical extension structure changing from the sitting position to the TV position, the fourth limiting rod abuts against the base. When the mechanical extension structure is in the lying position, and during the process of the mechanical extension structure changing from the TV position to the lying position, the fourth limiting rod does not abut against the base. The mechanical extension structure according to claim 5 is characterized in that, The base is equipped with a fifth limiting rod, and the internal swing assembly also includes: The front swing plate has one end rotatably connected to the front support plate and the other end rotatably connected to the base plate. A swing connecting plate, one end of which is rotatably connected to the front swing plate, and the other end of which is rotatably connected to the rear swing plate; The intermediate swing plate is rotatably connected to the base plate. The upper swing plate has one end rotatably connected to the front support plate and the other end rotatably connected to the middle swing plate. The lower swing plate has one end rotatably connected to the leg assembly and the other end rotatably connected to the middle swing plate. Specifically, when the mechanical extension structure is in the seated position, when the mechanical extension structure is in the TV position, and during the process of the mechanical extension structure changing from the seated position to the TV position, the fifth limiting rod abuts against the front swing plate, and the fifth limiting rod is located above the front swing plate. The mechanical extension structure according to claim 10 is characterized in that, The rear swing plate is provided with a fourth limiting rod. When the mechanical extension structure is in the sitting position, when the mechanical extension structure is in the TV position, and during the process of the mechanical extension structure changing from the sitting position to the TV position, the fourth limiting rod supports the base and the front swing plate supports the fifth limiting rod. When the mechanical extension structure is in the lying position, and during the process of the mechanical extension structure changing from the TV position to the lying position, the fourth limit rod does not abut against the base; When the fourth limiting rod supports the base and the front swing plate supports the fifth limiting rod, the rear swing plate prevents the base from sinking relative to the base through the fourth limiting rod, and the front swing plate prevents the base from sinking relative to the base through the fifth limiting rod. The mechanical stretching structure according to claim 11, characterized in that The front swing plate is located in front of the rear swing plate; The mounting surface is located below the fifth limiting rod, and / or the mounting surface is located above the fourth limiting rod. The mechanical stretching structure according to claim 11, characterized in that The mounting surface is located on the outside of the base, and / or the fifth limit rod and the front swing plate are located on the inside of the base. The mechanical expanse structure according to claim 11, characterized in that The front swing plate is provided with a sixth limiting rod, and the middle swing plate is provided with a ninth limiting rod. When the mechanical extension structure is in the sitting position, the upper end face of the front part of the swing link supports the sixth limiting rod, and the upper end face of the rear part of the swing link abuts against the ninth limiting rod. When the mechanical extension structure is in the TV position, and during the process of the mechanical extension structure changing from the sitting position to the TV position, the upper end face of the front part of the swing link supports the sixth limiting rod, and the ninth limiting rod separates from the swing link. When the mechanical extension structure is in a seated position, the fifth limiting rod is located between the front support plate and the sixth limiting rod. The mechanical stretching structure according to any one of claims 1-14, characterized in that The front support of the backrest is located behind the middle swing plate. The front support of the backrest is equipped with a third limiting rod. The base is provided with an upper groove with the opening facing upward. When the mechanical extension structure is in the lying position, the backrest plate abuts against the third limiting rod, and the third limiting rod abuts against the groove wall of the upper groove. The mechanical stretching structure according to any one of claims 1-14, characterized in that The backrest assembly also includes a backrest rear support, a first backrest support, a second backrest support, and a third backrest support. One end of the backrest rear support is rotatably connected to the backrest panel, and the other end of the backrest rear support is rotatably connected to the base. One end of the first backrest support is rotatably connected to the front backrest support, and the other end of the first backrest support is rotatably connected to one end of the second backrest support. The second backrest support is rotatably connected to the base, and the other end of the second backrest support is rotatably connected to one end of the third backrest support. The other end of the third backrest support is rotatably connected to the base. The backrest front support is equipped with a third limiting rod. When the mechanical extension structure is in the sitting position, the second backrest support abuts against the third limiting rod. When the mechanical extension structure is in the reclining position, or during the process of the mechanical extension structure changing from the TV position to the reclining position, the second backrest support does not abut against the third limiting rod. The mechanical extension structure according to claim 16 is characterized in that, The backrest is equipped with a seventh limiting rod. When the mechanical extension structure is in the sitting position, when the mechanical extension structure is in the TV position, and when the mechanical extension structure changes from the sitting position to the reclining position, the seventh limiting rod does not abut against the front support of the backrest; when the mechanical extension structure is in the reclining position, the seventh limiting rod abuts against the front support of the backrest. And / or, the base is provided with an eighth limiting rod, which does not abut against the front support of the backrest when the mechanical extension structure is in the sitting position, when the mechanical extension structure is in the TV position, or when the mechanical extension structure changes from the sitting position to the reclining position; and abuts against the front support of the backrest when the mechanical extension structure is in the reclining position. Seat unit, characterized in that The mechanical extension structure includes any one of claims 1-17, wherein the first drive mechanism includes a motor and a telescopic assembly, the motor is provided with a motor shaft, the motor shaft is connected to the telescopic assembly through a transmission mechanism, the motor is located on the base, and the telescopic assembly is also movably connected to one of the linkage rod and the leg assembly. The seat unit according to claim 18 is characterized in that, The motor is movably mounted on the base, and the center line of the motor shaft coincides with the center line of the telescopic assembly. The telescopic assembly includes an outer rod and an inner rod located inside the outer rod. The outer rod and the inner rod are threaded together, and the motor shaft and the inner rod are connected through a transmission mechanism. During the operation of the motor, the rotational speed of the motor shaft is different from the rotational speed of the inner rod. The seat unit according to claim 19, characterized in that The leg assembly includes a drive rod, an outer rod rotatably connected to the drive rod, and the drive rod rotatably connected to the base; And / or, the motor includes a body with a protective cover fitted over an outer rod. When the mechanical extension structure is in a seated position, the transmission rod is exposed outside the protective cover; when the mechanical extension structure is in a reclining position, the inner rod is not exposed outside the protective cover. Seat unit, characterized in that The mechanical extension structure includes any one of claims 1-17, wherein the first drive mechanism includes a motor and a telescopic assembly, the motor is provided with a motor shaft, the motor shaft is connected to the telescopic assembly through a transmission mechanism, the motor is located on a base, and the telescopic assembly is also movably connected to one of the linkage rod and the leg assembly. The seat unit according to claim 21, characterized in that The motor is movably mounted on the base, and the center line of the motor shaft coincides with the center line of the telescopic assembly. The telescopic assembly includes an outer rod and an inner rod located inside the outer rod. The outer rod and the inner rod are threaded together, and the motor shaft and the inner rod are connected through a transmission mechanism. During the operation of the motor, the rotational speed of the motor shaft is different from the rotational speed of the inner rod. The seat unit according to claim 22, characterized in that The leg assembly includes a drive rod, an outer rod rotatably connected to the drive rod, and the drive rod rotatably connected to the base; And / or, the motor includes a body with a protective cover fitted over an outer rod. When the mechanical extension structure is in a seated position, the transmission rod is exposed outside the protective cover; when the mechanical extension structure is in a reclining position, the inner rod is not exposed outside the protective cover. Seat unit, characterized in that The mechanical extension structure includes any one of claims 5-17, wherein the first drive mechanism includes a motor and a telescopic assembly, the motor has a motor shaft, the motor shaft is connected to the telescopic assembly through a transmission mechanism, one of the motor and the telescopic assembly is movably disposed on the leg assembly, and the other of the two is movably connected to the swing mechanism. The seat unit according to claim 24, characterized in that The centerline of the motor shaft coincides with the centerline of the telescopic assembly. The telescopic assembly includes an outer rod and an inner rod located inside the outer rod. The outer rod and the inner rod are threaded together, and the motor shaft and the inner rod are connected through a transmission mechanism. During the operation of the motor, the rotational speed of the motor shaft is different from the rotational speed of the inner rod. The seat unit according to claim 25, characterized in that The leg assembly includes a transmission rod, a motor rotatably connected to the transmission rod, and an outer rod rotatably connected to the swing mechanism; And / or, the motor includes a body with a protective cover fitted over an outer rod. When the mechanical extension structure is in a seated position, the transmission rod is exposed outside the protective cover; when the mechanical extension structure is in a reclining position, the inner rod is not exposed outside the protective cover. Sofa comprising a backrest structure and a seat cushion structure, characterized in that It includes at least one seat unit as described in any one of claims 18-26; wherein the backrest structure is detachably disposed on the backrest assembly, and / or the seat cushion structure is attached to the base. The sofa according to claim 27, characterized in that The backrest structure is provided with a buckle plate, and the backrest plate is provided with a mounting hole. The mounting hole is a stepped hole. The buckle plate is inserted into the mounting hole and abuts against the stepped surface of the stepped hole to fix the backrest structure to the backrest plate. The distance between the stepped surface and the large-diameter end opening of the stepped hole is <2mm. The sofa according to claim 27, characterized in that The sofa includes a snap-on plate, a first slide rail on the backrest structure, the snap-on plate can slide along the first slide rail, and mounting holes are provided on the backrest panel. The snap-on plate is inserted into the mounting holes to fix the backrest structure to the backrest panel. Among them, an elastic element is provided between the buckle plate and the backrest structure. The buckle plate moves along the first slide rail to change the shape of the elastic element. The sofa according to claim 29, characterized in that The elastic element is a compression spring. During the process of the mechanical extension structure changing from a sitting position to a lying position, the backrest structure moves backward relative to the seat cushion structure, so that the buckle plate moves relative to the first slide rail and squeezes the compression spring; during the process of the mechanical extension structure changing from a lying position to a sitting position, the backrest structure moves forward relative to the seat cushion structure, and the compression spring pushes the buckle plate to move along the first slide rail. The sofa according to claim 27, characterized in that The mechanical extension structure also includes a second slide rail and a sliding member. The sliding member is provided with a leg structure. The second slide rail is located on the base. The sliding member is slidably located on the second slide rail and slides relative to the second slide rail so that the leg structure moves closer to or further away from the seat structure. The sofa according to claim 31, characterized in that The second slide rail is fixedly connected to the base. When the mechanical extension structure is in a sitting position, the leg structure is located below the seat cushion structure. During the process of the mechanical extension structure changing from a sitting position to a lying position, the leg structure moves outward relative to the seat cushion structure. Alternatively, the second slide rail is movably connected to the base, so that when the mechanical extension structure is in a sitting position, the leg structure is located below the seat cushion structure; during the process of the mechanical extension structure changing from a sitting position to a lying position, the leg structure rotates upward relative to the seat cushion structure. The sofa according to claim 32 is characterized in that, When the second slide rail is fixedly connected to the base, the second slide rail is located below the leg structure, and the leg structure and the seat cushion structure are connected by the sofa fabric; when the second slide rail is movably connected to the base, the second slide rail is located on the side of the leg structure, and the leg structure and the seat cushion structure are integrated. The sofa according to claim 27 is characterized in that, The seat cushion structure includes a hook with an anti-slip part, and a base with a hanging rod for hanging the hook. The hanging rod has at least two mating parts, and when the hook is hung on the hanging rod, the anti-slip part abuts against one of the mating parts. The control method of the sofa is characterized in that, The sofa includes the sofa according to any one of claims 27-34, and the sofa further includes: The headrest structure is movably mounted above the backrest structure; The second drive mechanism has one end rotatably connected to the backrest structure and the other end rotatably connected to the headrest structure. A control switch is electrically connected to the first drive mechanism and the second drive mechanism; A signal acquisition device is used to collect electrical signals; The controller, signal acquisition unit, and control switch are electrically connected to the controller. Sofa control methods include: The signal acquisition device transmits the acquired electrical signals to the controller. Based on the electrical signals, the controller controls the first drive mechanism and the second drive mechanism to work through the control switch, so that the mechanical extension structure can change between a sitting position and a lying position, and the second drive mechanism can adjust the position of the headrest structure relative to the backrest structure. The sofa control method according to claim 35 is characterized in that, The sofa includes two seat units. The signal acquisition unit includes a first voice acquisition module and a second voice acquisition module. The first voice acquisition module is used to collect a first electrical signal from one of the seat units, and the second voice acquisition module is used to collect a second electrical signal from the other seat unit. The sofa control method according to claim 35 is characterized in that, The sofa includes two seat units. The signal acquisition unit includes a first voice acquisition module and a second voice acquisition module. The first voice acquisition module is adjacent to one of the seat units, and the second voice acquisition module is adjacent to the other seat unit. A signal comparison module is provided between the first voice acquisition module, the second voice acquisition module and the controller. The signal comparison module is used to determine the magnitude of the voltage or current value of different electrical signals. The first electrical signal acquired by the first voice acquisition module and the second electrical signal acquired by the second voice acquisition module are respectively transmitted to the signal comparison module. The signal comparison module transmits one of the first electrical signal and the second electrical signal to the controller. The controller controls the first drive mechanism on a seat unit to work through a control switch, so that the first drive mechanism on the seat unit adjusts the position of the base relative to the base. The sofa control method is characterized by, The sofa includes the sofa according to any one of claims 27-34, and the sofa further includes: Gravity sensor, used to collect real-time gravity signals, is located in the seat cushion structure and / or backrest structure; The control switch is electrically connected to the first drive mechanism; A signal acquisition device is used to acquire real-time voice signals. The controller, gravity sensor, signal acquisition unit, and control switch are electrically connected to the controller. Sofa control methods include: When the gravity sensor acquires a real-time gravity signal, the signal acquisition device is activated to collect real-time voice signals. The signal acquisition unit identifies the real-time voice signal to determine whether the real-time voice signal includes a wake word; After determining that the real-time voice signal collected by the signal collector includes a wake-up word, the signal collector collects a real-time voice signal containing control commands and transmits the real-time voice signal containing control commands to the controller. Based on the real-time voice signal, the controller controls the first drive mechanism to work through a control switch so that the mechanical extension structure can change between a sitting position and a lying position. The control method of the sofa according to claim 38, wherein The sofa also includes an ambient light, which is electrically connected to a control switch. The gravity sensor transmits the real-time gravity signal it collects to the controller. After receiving the real-time gravity signal, the controller turns on the ambient light through the control switch. The sofa control method according to claim 38 is characterized in that, The sofa also includes an ambient light and a photosensitive sensor for collecting real-time light signals. The ambient light is electrically connected to the control switch, and the photosensitive sensor is electrically connected to the controller. The controller presets a specified light signal and a specified gravity signal. The gravity sensor collects the real-time gravity signal and transmits it to the controller. The photosensitive sensor collects the real-time light signal and transmits it to the controller. After comparing the specified gravity signal with the real-time gravity signal and the specified light signal with the real-time light signal, the controller turns the ambient light on or off by controlling the switch. The sofa control method according to claim 40 is characterized in that, The gravity sensor transmits the real-time gravity signal it collects to the controller. After the controller determines that the specified gravity signal value is greater than the real-time gravity signal value, the controller receives the real-time light signal collected by the photosensitive sensor. After the controller determines that the specified light signal value is greater than the real-time light signal value, the controller turns on the ambient light by controlling the switch. The control method of the sofa is characterized by, The sofa includes the sofa according to any one of claims 27-34, and the sofa further includes: Ambient lighting is installed on the seat cushion structure and / or backrest structure; Gravity sensor, used to collect real-time gravity signals, is located in the seat cushion structure and / or backrest structure; A photosensitive sensor is used to collect real-time light signals; The control switch is electrically connected to the first drive mechanism and the ambient light. The controller, gravity sensor, photosensor, and control switch are electrically connected to the controller. Sofa control methods include: The controller presets a specified light signal and a specified gravity signal. The gravity sensor collects the real-time gravity signal and transmits it to the controller. The photosensitive sensor collects the real-time light signal and transmits it to the controller. After comparing the specified gravity signal with the real-time gravity signal and the specified light signal with the real-time light signal, the controller turns the ambient light on or off by controlling the switch. The control method of the sofa is characterized by, The sofa includes the sofa according to any one of claims 27-34, and the sofa further includes: Gravity sensor, used to collect real-time gravity signals, is located in the seat cushion structure and / or backrest structure; A first position sensor is electrically connected to a first drive mechanism, and the first position sensor is used to collect the first real-time position signal of the first drive mechanism. The control switch is electrically connected to the first drive mechanism; The controller, the first position sensor, the gravity sensor, and the control switch are electrically connected to the controller respectively; Sofa control methods include: The controller presets a first designated position signal. When the gravity sensor fails to collect a real-time gravity signal, the controller collects the first real-time position signal from the first position sensor and determines whether the mechanical extension structure is in a seated position by comparing the first designated position signal with the first real-time position signal. When the controller determines that the mechanical extension structure is in the seated position, the controller stops the first drive mechanism from working by controlling the switch; when the controller determines that the mechanical extension structure is not in the seated position, the controller controls the first drive mechanism to work by controlling the switch, and the first drive mechanism adjusts the position of the base relative to the base until the mechanical extension structure is in the seated position. The control method of the sofa is characterized by, The sofa includes the sofa according to any one of claims 27-34, and the sofa further includes: Gravity sensor, used to collect real-time gravity signals, is located in the seat cushion structure and / or backrest structure; A first position sensor is electrically connected to a first drive mechanism, and the first position sensor is used to collect the first real-time position signal of the first drive mechanism. The control switch is electrically connected to the first drive mechanism; The timer module is used to calculate the real-time gravity signal acquisition time; The controller, the first position sensor, the gravity sensor, the control switch, and the timer module are all electrically connected to the controller. Sofa control methods include: The controller presets the first designated position signal and the real-time gravity signal acquisition time. When the mechanical extension structure is not in the seated position, the controller acquires the real-time gravity signal for the first time through the gravity sensor. When the gravity sensor fails to collect a real-time gravity signal for the first time, the timer module starts working. After the timer module reaches the real-time gravity signal collection time, the controller collects the first real-time position signal from the first position sensor and determines whether the mechanical extension structure is in a seated position by comparing the first designated position signal with the first real-time position signal. When the controller determines that the mechanical extension structure is not in a seated position, the controller controls the first drive mechanism to work through the control switch. The first drive mechanism adjusts the position of the base relative to the base until the mechanical extension structure is in a seated position. The control method of the sofa is characterized in that, The sofa includes the sofa according to any one of claims 27-34, and the sofa further includes: Gravity sensor, used to collect real-time gravity signals, is located in the seat cushion structure and / or backrest structure; A first position sensor is electrically connected to a first drive mechanism, and the first position sensor is used to collect the first real-time position signal of the first drive mechanism. The control switch is electrically connected to the first drive mechanism; The timer module is used to calculate the real-time gravity signal acquisition time; The controller, the first position sensor, the gravity sensor, the control switch, and the timer module are all electrically connected to the controller. Sofa control methods include: The controller presets the first designated position signal and the real-time gravity signal acquisition time. When the mechanical extension structure is not in the seated position, the controller acquires the real-time gravity signal for the first time through the gravity sensor. When the gravity sensor fails to collect a real-time gravity signal for the first time, the timer module starts working. After the timer module reaches the real-time gravity signal collection time, the controller collects the real-time gravity signal a second time through the gravity sensor. When the gravity sensor fails to collect a real-time gravity signal for the second time, the controller collects the first real-time position signal from the first position sensor and determines whether the mechanical extension structure is in a seated position by comparing the first designated position signal with the first real-time position signal. When the controller determines that the mechanical extension structure is not in a seated position, the controller controls the first drive mechanism to work through the control switch. The first drive mechanism adjusts the position of the base relative to the base until the mechanical extension structure is in a seated position. The control method of the sofa is characterized in that, The sofa includes the sofa according to any one of claims 27-34, and the sofa further includes: The headrest structure is movably mounted above the backrest structure; The second drive mechanism has one end rotatably connected to the backrest structure and the other end rotatably connected to the headrest structure. A control switch is electrically connected to the first drive mechanism and the second drive mechanism; A first position sensor is electrically connected to a first drive mechanism, and the first position sensor is used to collect the first real-time position signal of the first drive mechanism. The second position sensor is electrically connected to the second drive mechanism and is used to acquire the second real-time position signal of the second drive mechanism. The controller, the first position sensor, the second position sensor, and the control switch are electrically connected to the controller; Sofa control methods include: The controller presets a first designated position signal and a second designated position signal. The first position sensor transmits the first real-time position signal it collects to the controller, and the second position sensor transmits the second real-time position signal it collects to the controller. After comparing the first real-time position signal with the first designated position signal and comparing the second real-time position signal with the second designated position signal, the controller drives the first drive mechanism and the second drive mechanism to work through the control switch, so that the mechanical extension structure changes between the sitting position and the reclining position, and the second drive mechanism adjusts the position of the headrest structure relative to the backrest structure. The control method of the sofa is characterized by, The sofa includes the sofa according to any one of claims 27-34, and the sofa further includes: An anti-pinch sensor is used to detect the real-time electrical signal of the first drive mechanism; The control switch is electrically connected to the first drive mechanism; The controller, anti-pinch sensor, and control switch are electrically connected to the controller. Sofa control methods include: The controller presets a reference electrical signal. The anti-pinch sensor transmits the collected real-time electrical signal to the controller. The controller compares the real-time electrical signal with the reference electrical signal. When the real-time electrical signal is greater than or equal to the reference electrical signal, the controller drives the first drive mechanism through the control switch to change the mechanical extension structure to a lying position. The control method of the sofa is characterized by, The sofa includes the sofa according to any one of claims 27-34, and the sofa further includes: An anti-pinch sensor is used to detect the real-time electrical signal of the first drive mechanism; The control switch is electrically connected to the first drive mechanism; The controller, anti-pinch sensor, and control switch are electrically connected to the controller. Sofa control methods include: The controller presets a reference electrical signal. The anti-pinch sensor transmits the first real-time electrical signal and the second real-time electrical signal it collects to the controller. The controller compares the reference electrical signal with the difference between the first real-time electrical signal and the second real-time electrical signal. When the difference between the first real-time electrical signal and the second real-time electrical signal is greater than or equal to the reference electrical signal, the controller drives the first drive mechanism through the control switch to change the mechanical extension structure to a lying position. The control method of the sofa is characterized by, The sofa includes the sofa according to any one of claims 27-34, and the sofa further includes: The controller includes an interactive processing unit, which has a signal input terminal and a signal output terminal. The display unit is used to display the navigation menu and sub-menus, and the signal output terminal of the interactive processing unit is connected to the display unit. The operation button is connected to the signal input terminal of the interactive processing unit. Pressing or rotating an operation button will cause the display unit to display the corresponding menu information. Sofa control methods include: S01) Press the operation button in navigation mode to enter the submenu of the current menu item, enter the editing mode of the current menu item, or return to the parent menu of the current menu item. If entering the submenu or returning to the parent menu, return to step S03). If entering the editing mode, proceed to step S02. S02) In edit mode, rotate the operation button to modify the parameters, and press the operation button to confirm that the parameter modification is complete. S03) Press the operation button to enter the submenu or return to the previous menu. An electronic device, characterized by include: A memory and a processor, the processor being configured to run a program stored in the memory, wherein the program, when running, performs the control method of the sofa according to any one of claims 35-49.

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