Mechanical stretching structure and seat unit

Abstract

The invention relates to a mechanical stretching structure and a seat unit. The problems that a seat unit is complex in structure and inconvenient to operate are solved. The mechanical stretching structure comprises a control switch, the control switch comprises two switch keys and a switch base, the switch base is provided with two common ends, two normally closed ends and two normally open ends, and each switch key is connected with one common end and one normally closed end, or the switch key is connected with one common end and one normally open end; wherein one common end is electrically connected with the positive electrode of the driving device, the other common end is electrically connected with the negative electrode of the driving device, the two normally closed ends are connected with the negative electrode of the power supply, and the two normally open ends are connected with the positive electrode of the power supply.

Description

Technical Field

[0001] The invention relates to a mechanical extension structure and a seat unit. Background Art

[0002] In the prior art, a variety of seat units are disclosed, which include 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 lying position. When the control switch controls the mechanical extension structure to change from the sitting position to the lying position, the leg rest structure extends toward the front of the seat cushion structure and the backrest structure leans back. When the control switch controls the mechanical extension structure to change from the lying position to the sitting position, the leg rest structure retracts toward the bottom of the seat cushion structure and the backrest structure returns to its normal position.

[0003] However, the existing mechanical extension structure has the disadvantages of complex structure and inconvenient operation in order to achieve switching back and forth between the sitting position and the lying position. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a mechanical extension structure and a seat unit, which solves the problem of complex structure and inconvenient operation of the seat unit.

[0005] In order to solve the above technical problems, the present invention is solved by the following technical solutions:

[0006] The mechanical extension structure includes a base, a pedestal, a backrest assembly, a leg assembly, a swing mechanism and a driving device, the base and the pedestal are movably connected through the swing mechanism, the leg assembly is movably arranged in front of the base, the backrest assembly is movably arranged at the rear of the base, and the driving device is arranged at the base;

[0007] The mechanical extension structure has a sitting position and a lying position. When the mechanical extension structure is changed from the sitting position to the lying position, the driving device drives the base and the swing mechanism to move forward through the leg assembly, and the leg assembly is extended in front of the base, and the backrest assembly is tilted back relative to the base; when the mechanical extension structure is changed from the lying position to the sitting position, the driving device drives the base and the swing mechanism to move backward through the leg assembly, and the leg assembly is folded under the base, and the backrest assembly is returned to the normal position relative to the base;

[0008] The mechanical extension structure also includes a control switch, which includes two switch keys and a switch base, and the switch base is provided with two common terminals, two normally closed terminals and two normally open terminals, and each switch key connects one of the common terminals with one of the normally closed terminals, or connects one of the common terminals with one of the normally open terminals;

[0009] Among them, one of the common terminals is electrically connected to the positive pole of the driving device, the other common terminal is electrically connected to the negative pole of the driving device, the two normally closed terminals are both connected to the negative pole of the power supply, and the two normally open terminals are both connected to the positive pole of the power supply. When the mechanical extension structure changes from a sitting position to a lying position, one of the switch keys connects one of the common terminals and one of the normally open terminals, and the other switch key connects the other common terminal and the other normally closed terminal; when the mechanical extension structure changes from a lying position to a sitting position, one of the switch keys connects one of the common terminals and one of the normally closed terminals, and the other switch key connects the other common terminal and the other normally open terminal.

[0010] In the present invention, the structure of the seat unit is simplified by optimizing the structure of the control switch.

[0011] The control switch includes a first switch key and a second switch key. The first switch key and the second switch key can realize the driving device controlling the mechanical extension structure to switch back and forth between the sitting position and the lying position through six electrical connection lines. The six electrical connection lines include: the second common end is electrically connected to the positive pole of the driving device through the first electrical connection line, the first common end is electrically connected to the negative pole of the driving device through the second electrical connection line, the first normally closed end is electrically connected to the second normally closed end through the third electrical connection line, the first normally closed end is electrically connected to the negative pole of the power supply through the fourth electrical connection line, the first normally open end is electrically connected to the second normally open end through the fifth electrical connection line, and the second normally open end is electrically connected to the positive pole of the power supply through the sixth electrical connection line.

[0012] Preferably, the control switch also includes a reaction force spring, the switch key is arranged on the switch seat and can abut the switch seat, the reaction force spring is clamped between the switch key and the switch seat, when the reaction force spring releases the elastic force to push the switch key to abut the switch seat, the switch key connects one of the common ends and one of the normally closed ends; when the switch key squeezes the reaction force spring and separates from the switch seat, the switch key connects one of the common ends and one of the normally open ends.

[0013] When the control switch also includes a reaction spring, the control switch is a physical switch; the reaction spring can automatically cut off the power supply of the drive device through its own elastic force, that is, the mechanical extension structure realizes automatic power cut-off of the control switch by adding one part. This structure makes the mechanical extension structure simple in structure and improves the operating convenience of the seat unit.

[0014] Preferably, the power supply includes an external power supply, and the two normally open ends are respectively electrically connected to the positive electrode of the external power supply through a voltage converter;

[0015] And / or, the power supply includes a battery, and the two normally open terminals are electrically connected to the positive poles of the battery respectively.

[0016] The voltage between the live wire and the neutral wire of domestic civil electricity is usually 220V, but the voltage of the drive device (the input voltage of the drive device is usually around 24V) does not need to be so high. Therefore, the first normally open end and the second normally open end need to be connected to an external power supply through a voltage converter.

[0017] When the power supply is a battery, the mechanical extension structure can realize the conversion between the sitting position and the lying position without connecting an external power supply.

[0018] Preferably, when the power supply includes an external power supply and a battery, the mechanical extension structure further includes a controller, a protection switch and a sensor, the positive electrode of the battery is electrically connected to the controller through the sensor, the battery is connected to the external power supply through the protection switch, and the controller is electrically connected to the protection switch and is used to connect or disconnect the circuit between the battery and the external power supply. The battery and the controller improve the operating convenience of the seat unit, that is, when the external power supply is powered off, the seat unit can also use its own battery for power supply, so that the mechanical extension mechanism is in a sitting position or a lying position.

[0019] The controller may be an MCU, a CPU, or a microprocessor (MicroProcessor Unit).

[0020] According to the prior art, it is known that the charging voltage of a battery with a storage capacity of 50%, the charging voltage of a battery with a storage capacity of 80%, and the charging voltage of a battery with a storage capacity of 95% are different; the charging current of a battery with a storage capacity of 50%, the charging current of a battery with a storage capacity of 80%, and the charging current of a battery with a storage capacity of 95% are different.

[0021] The sensor can be a voltage sensor, and the controller obtains the real-time charging voltage of the positive electrode of the battery through the sensor; since the charging voltage of the battery is different at different storage capacities, the controller obtains the real-time charging voltage of the positive electrode of the battery through the sensor to enable the controller to monitor the storage capacity of the battery.

[0022] Similarly, the sensor can also be a current sensor, and the controller obtains the real-time charging current of the positive electrode of the battery through the sensor. Since the charging current of the battery is different at different storage capacities, the controller obtains the real-time charging current of the positive electrode of the battery through the sensor to enable the controller to monitor the storage capacity of the battery.

[0023] Since the battery is connected to the external power supply through a protection switch, after the controller obtains that the storage capacity of the battery reaches the preset maximum storage capacity, the controller disconnects the circuit between the battery and the external power supply through the protection switch; after the controller obtains that the storage capacity of the battery reaches the preset minimum storage capacity, the controller connects the circuit between the battery and the external power supply through the protection switch. The battery has a charge and discharge service life, and the controller automatically connects or disconnects the circuit between the battery and the external power supply through the protection switch to increase the service life of the battery.

[0024] Preferably, the driving device is electrically connected to the external power supply via one of a triode, a MOS tube, and a relay, and the controller is electrically connected to one of the triode, the MOS tube, and the relay.

[0025] One of the triode, MOS tube and relay is used to connect or disconnect the circuit between the driving device and the external power supply.

[0026] Taking the transistor as an example, the controller can be electrically connected to the touch screen. When the controller is electrically connected to the touch screen and the driving device is connected to the external power supply through the transistor, the touch screen changes the state of the transistor through the controller to connect or disconnect the circuit between the driving device and the external power supply.

[0027] In addition, the drive device and the external power supply can also be electrically connected via a micro switch.

[0028] Preferably, the mechanical extension structure further comprises a controller and a wireless signal receiving module, and the wireless signal receiving module is electrically connected to the control switch through the controller. The wireless signal receiving module and the controller realize remote control of the control switch, and this structure effectively improves the operating convenience of the seat unit.

[0029] When the mechanical extension structure also includes a controller and a wireless signal receiving module, the control switch includes one or more of a transistor, a MOS tube, and a relay. After the wireless signal receiving module receives a control signal from a remote control device (for example, a mobile phone, a tablet computer, a remote control), the control signal is transmitted to the controller. The controller controls the switch to enable the driving device to control the mechanical extension structure to switch back and forth between a sitting position and a lying position.

[0030] Preferably, the controller is electrically connected to the massager, and the controller is arranged on the switch seat. When the controller is arranged on the switch seat, all functions on the controller can be integrated on the switch seat and controlled by the switch seat.

[0031] Preferably, the mechanical extension structure also includes at least one charging socket, at least one charging socket is arranged on the switch seat, and the charging socket includes a Type-C interface.

[0032] Mobile phones and tablets can be connected to the Type-C interface via a data cable, so that users can charge their phones or tablets while sitting in the seat unit.

[0033] The seat unit includes the mechanical extension structure described in any one of the above technical solutions, the leg assembly includes a main legrest mounting plate, a front legrest rotating plate, a rear legrest rotating plate, a front legrest connecting plate and a rear legrest connecting plate, one end of the front legrest rotating plate and one end of the rear legrest rotating plate are respectively rotatably connected to the main legrest mounting plate, the other end of the front legrest rotating plate is rotatably connected to one end of the front legrest connecting plate, the other end of the rear legrest rotating plate is rotatably connected to one end of the rear legrest connecting plate, and the other end of the front legrest connecting plate and the other end of the rear legrest connecting plate are respectively rotatably connected to the base;

[0034] Wherein, one of the rear leg rest rotating plate and the front leg rest connecting plate is provided with a leg support mechanism, and when the mechanical extension structure is in a lying position, the leg support mechanism abuts against the other of the two.

[0035] When the mechanical extension structure is in a lying position and the leg support mechanism abuts against one of the rear leg rest rotating plate and the front leg rest connecting plate, the user (or maintenance personnel) can remove the driving device; during the process of the user removing the driving device, since the leg support mechanism abuts against one of the rear leg rest rotating plate and the front leg rest connecting plate, the shape of the leg assembly will hardly change, that is, the main footrest structure will not hit the user during the process of the user removing the driving device.

[0036] In addition, when the mechanical extension structure is in the lying position, the user can remove the drive device. This structure can effectively reduce the difficulty of repairing the seat unit, that is, improve the convenience of the seat unit repair operation.

[0037] The seat unit also includes a backrest structure and an armrest structure. The backrest assembly can be movably arranged on the backrest structure. The armrest structure includes an armrest frame. The armrest frame includes two side armrest panels and a rear armrest panel. The base is fixedly connected to the side armrest panels. The two side armrest panels are fixedly connected through the rear armrest panel. When the mechanical extension structure is in a lying position, the interval distance between the rear armrest panel and the backrest structure is ≥10cm.

[0038] The width of a user's arm is usually about 10 cm. Therefore, when the mechanical extension structure is in a lying position and the distance between the rear armrest plate and the backrest structure is ≥ 10 cm, the user's arm can be extended into the armrest frame through the gap between the backrest structure and the rear armrest plate to achieve disassembly and assembly of the drive device. This structure further improves the convenience of seat unit maintenance operations.

[0039] Preferably, the seat unit also includes a main legrest structure, which includes a main legrest board and a main legrest decorative cover. The main legrest board is fixedly connected to the main legrest mounting plate, and the main legrest decorative cover is detachably arranged on the main legrest board.

[0040] In the prior art, the main legrest decorative cover is installed on the main legrest board in a semi-permanent manner, for example, the main legrest decorative cover is fixed on the main legrest board by nails of a pneumatic gun; or, the main legrest decorative cover is fixed on the main legrest board by hammering nails with a hammer. This makes the main legrest structure assembly speed slow and the manufacturing cost high.

[0041] When the main legrest decorative cover is detachably arranged on the main legrest board, the main legrest decorative cover can be installed on the main legrest board without the aid of external tools; the main legrest decorative cover can also be removed from the main legrest board without the aid of external tools. This structure improves the convenience of disassembling, assembling and replacing the main legrest board.

[0042] The auxiliary leg rest structure is the same as the main leg rest structure, so it will not be described in detail.

[0043] Preferably, the main footrest decorative cover is hung on the main legrest board; or, the main footrest decorative cover is provided with a first opening, the main legrest board is placed into the main footrest decorative cover through the first opening, and the main footrest decorative cover is provided with a first sealing structure at the first opening, and the first sealing structure includes one of a first linear zipper and a first arc zipper.

[0044] When the main leg rest decorative cover is provided with the first opening, the first opening can increase the deformation dimension of the main leg rest decorative cover, so as to reduce the difficulty of the main leg rest board entering the main leg rest decorative cover.

[0045] The first straight zipper, the first arc zipper and the first buckle structure are all prior art, so the above structures will not be described in detail; the first sealing structure adopts the first straight zipper, which has the advantages of simple structure and low cost; the first sealing structure adopts the first arc zipper, which has the advantage of easy disassembly and assembly of the main legrest; the first buckle structure has the advantage that the sealing structure is not easy to open, and the first buckle structure includes a clamp and a fastener, the clamp is arranged on one side of the main legrest decorative cover located at the first opening, and the fastener is arranged on the other side of the main legrest decorative cover located at the first opening. Of course, the first sealing structure can facilitate the replacement of the footrest decorative cover and the cleaning of the footrest decorative cover.

[0046] The width of the first arc-shaped zipper is greater than the width of the main legrest board, which enables the first arc-shaped zipper to further increase the size of the first opening that can be deformed. This structure further reduces the probability of the first opening being damaged during the installation of the main legrest board.

[0047] Preferably, the leg assembly further comprises an auxiliary leg rest mounting plate and a rear leg rest extension plate, one end of the main leg rest mounting plate and the rear leg rest extension plate are respectively rotatably connected to the auxiliary leg rest mounting plate, and the other end of the rear leg rest extension plate is rotatably connected to one end of the front leg rest rotation plate;

[0048] Or, the leg assembly also includes an auxiliary leg rest mounting plate, a front leg rest extension plate, a rear leg rest extension plate and a control rod, one end of the front leg rest extension plate and one end of the rear leg rest extension plate are respectively rotatably connected to the auxiliary leg rest mounting plate, the other end of the front leg rest extension plate and the other end of the rear leg rest extension plate are respectively rotatably connected to the main leg rest mounting plate, one of the front leg rest extension plate and the rear leg rest extension plate is rotatably connected to one end of the control rod, and the other end of the control rod is rotatably connected to one end of the front leg rest rotating plate.

[0049] The control lever is used to control the movement posture of the auxiliary leg rest mounting plate.

[0050] Preferably, the seat unit further comprises an auxiliary legrest structure, the auxiliary legrest structure comprises an auxiliary legrest plate and an auxiliary legrest decorative cover, the auxiliary legrest plate is fixedly connected to the auxiliary legrest mounting plate, and the auxiliary legrest decorative cover is detachably arranged on the auxiliary legrest plate. This structure improves the convenience of disassembly, assembly and replacement of the auxiliary legrest plate.

[0051] Preferably, the auxiliary footrest decorative cover is hung on the auxiliary legrest board; or, the auxiliary footrest decorative cover is provided with a second opening, the auxiliary legrest board is placed into the auxiliary footrest decorative cover through the second opening, and the auxiliary footrest decorative cover is provided with a second sealing structure at the second opening, and the second sealing structure includes one of a second linear zipper, a second arc zipper and a second snap structure.

[0052] The width of the second arc-shaped zipper is greater than the width of the auxiliary legrest, so that the second arc-shaped zipper further increases the size of the second opening that can be deformed. This structure further reduces the probability of the second opening being damaged during the installation of the auxiliary legrest.

[0053] Preferably, when the seat unit includes a main legrest structure, the main legrest plate is made of plastic, and the main legrest plate is fixedly connected to the main legrest mounting plate by screws or rivets; when the seat unit includes a secondary legrest structure, the secondary legrest plate is made of plastic, and the secondary legrest plate is fixedly connected to the secondary legrest mounting plate by screws or rivets.

[0054] The main legrest (auxiliary legrest) made of plastic is used to reduce the weight that the leg assembly needs to bear. This structure not only increases the service life of the seat unit, but also reduces the difficulty of carrying the seat unit.

[0055] When the main footrest decorative cover is hung on the main legrest board, the main footrest decorative cover is removed from the main legrest board to facilitate cleaning of the main footrest decorative cover.

[0056] The main legrest made of plastic is easy to shape, that is, the main legrest can be provided with a hook or a hanging ring for hanging the main footrest decorative cover by blow molding or extrusion molding. In addition, the main legrest made of plastic has another advantage, that is, the hook or the hanging ring can be formed by the concave of the main legrest, and this structure can effectively increase the regularity of the outer contour of the main legrest, and prevent the main footrest from damaging the user experience of the seat unit.

[0057] Preferably, a main legrest filler is provided in the main legrest decorative cover, and when the main legrest decorative cover is detachably provided on the main legrest board, the main legrest filler is clamped between the main legrest decorative cover and the main legrest board. The main legrest filler is used to increase the comfort of the user when resting his legs.

[0058] Preferably, the swing mechanism includes a first connecting rod, a second connecting rod, a third connecting rod, a first swing rod, a second swing rod, a third swing rod, a fourth swing rod, a first support rod and a second support rod, one end of the first support rod and one end of the second support rod are respectively rotatably connected to the base, the other end of the first support rod and the other end of the second support rod are respectively rotatably connected to the third connecting rod, the other end of the first swing rod and the other end of the third swing rod are respectively rotatably connected to the base, the other end of the second swing rod and the other end of the fourth swing rod are respectively rotatably connected to the third connecting rod, one end of the second swing rod is rotatably connected to the first swing rod, one end of the fourth swing rod is rotatably connected to the third swing rod, one end of the first connecting rod is rotatably connected to one end of the first swing rod, the other end of the first connecting rod is rotatably connected to the third swing rod, one end of the second connecting rod is rotatably connected to the first connecting rod, and the other end of the second connecting rod is rotatably connected to the fourth swing rod.

[0059] Preferably, the swing mechanism includes a first connecting rod, a second connecting rod, a third connecting rod, a first swing rod, a second swing rod, a third swing rod, a fourth swing rod, a first support rod and a second support rod, one end of the first support rod and one end of the second support rod are respectively rotatably connected to the base, the other end of the first support rod and the other end of the second support rod are respectively rotatably connected to the third connecting rod, the other end of the first swing rod and the other end of the third swing rod are respectively rotatably connected to the base, the other end of the second swing rod and the other end of the fourth swing rod are respectively rotatably connected to the third connecting rod, one end of the second swing rod is rotatably connected to the first swing rod, one end of the fourth swing rod is rotatably connected to the third swing rod, the other end of the first connecting rod is rotatably connected to the fourth swing rod, one end of the first connecting rod is rotatably connected to one end of the first swing rod, the other end of the second connecting rod is rotatably connected to the first connecting rod, and one end of the second connecting rod is rotatably connected to the second swing rod.

[0060] Preferably, the leg assembly further includes a linkage rod, one of the front leg rest connecting plate and the rear leg rest connecting plate is rotatably connected to one end of the linkage rod, and one of the first support rod and the first connecting rod is rotatably connected to the other end of the linkage rod.

[0061] During the process of the mechanical extension structure changing from a sitting position to a lying position (or during the process of the mechanical extension structure changing from a lying position to a sitting position), the linkage rod is used to increase the movement synchronization of the swing mechanism and the base to avoid incoordination between the leg assembly and the base, for example, interference between the leg assembly and the base, increase in the distance between the leg assembly and the base, decrease in the distance between the leg assembly and the base, etc.

[0062] Preferably, the driving device includes a driver, a driving rod is provided on the driver, a transmission rod is provided on the driving rod, the driver is rotatably connected to the base, and the front leg rest connecting plate and / or the rear leg rest connecting plate are rotatably connected to the transmission rod.

[0063] Preferably, the swing mechanism includes a first support rod and a second support rod, one end of the first support rod and one end of the second support rod are respectively rotatably connected to the base, and the other end of the first support rod and the other end of the second support rod are respectively rotatably connected to the base.

[0064] Preferably, the driving device comprises a driver, a screw rod, a push block and a transmission structure, the driver is fixedly connected to the base, the driver is provided with a driving rod fixedly connected to the screw rod, and the push block is threadedly connected to the screw rod;

[0065] The transmission structure includes a first transmission rod, a second transmission rod, a third transmission rod and a fourth transmission rod. The second transmission rod is rotatably connected to the base, the push block and the second transmission rod are respectively rotatably connected to the first transmission rod, the second transmission rod and the fourth transmission rod are respectively rotatably connected to the third transmission rod, and the front leg rest connecting plate and / or the rear leg rest connecting plate are rotatably connected to the fourth transmission rod.

[0066] Preferably, the swing mechanism includes a swing rod and a swing channel, the swing rod is arranged on the base, the swing channel is arranged on the base, and the swing rod can be inserted into the swing channel. When the swing rod is inserted into the swing channel, the driving device drives the base and the swing mechanism to move forward synchronously through the leg assembly so that the swing rod slides along the swing channel.

[0067] Preferably, the swing channel includes a horizontal section and / or an inclined section.

[0068] Preferably, one of the rear leg rest rotating plate and the front leg rest connecting plate is provided with a lying position limiting groove cooperating with the leg support mechanism, and when the mechanical extension structure is in the lying position, the leg support mechanism is inserted into the lying position limiting groove and abuts against the groove wall of the lying position limiting groove.

[0069] When the leg support mechanism is inserted into the lying position limiting groove and abuts against the groove wall of the lying position limiting groove, the lying position limiting groove prevents the rear leg rest rotating plate from moving relative to the front leg rest connecting plate through the leg support mechanism, so as to improve the stability of the user's legs after being placed on the main footrest structure.

[0070] Preferably, the width of the rear leg rest rotating plate is greater than the width of the front leg rest rotating plate, and the gap between the front leg rest rotating plate and the rear leg rest rotating plate is ≤5mm.

[0071] Since the thickness of a user's finger is usually more than 5 mm, the gap between the front leg rest rotating plate and the rear leg rest rotating plate is set to ≤ 5 mm to further reduce the probability of the user's finger being accidentally pinched. This structure reduces or prevents the user's finger from being inserted between the front leg rest rotating plate and the rear leg rest rotating plate by increasing the width of the rear leg rest rotating plate and reducing the gap between the front leg rest rotating plate and the rear leg rest rotating plate.

[0072] Preferably, the seat unit further comprises a seat cushion structure and an armrest structure, the base is fixedly connected to the seat cushion structure, and the base is fixedly connected to the armrest structure;

[0073] The control switch is arranged on the side of the seat cushion structure, and the control switch corresponds to the armrest structure; or the control switch is arranged on the side of the armrest structure, and the control switch is arranged tilted.

[0074] When the control switch is arranged on the side of the seat cushion structure and the control switch corresponds to the armrest structure, the probability of the control switch being impacted by external force is reduced, so as to increase the service life of the control switch.

[0075] In addition, when the control switch is arranged on the side of the seat cushion structure and the control switch corresponds to the armrest structure, the control switch becomes a hidden design. The hidden control switch can avoid damaging the appearance design of the seat unit. At the same time, the hidden control switch can also reduce the probability of the first switch key and the second switch key being accidentally touched.

[0076] When the control switch is arranged on the side of the armrest structure and the control switch is arranged at an angle, the user can press the first switch key and the second switch key by naturally bending his fingers, so as to improve the comfort of pressing the buttons.

[0077] Preferably, one of the rear leg rest rotating plate and the front leg rest connecting plate is provided with an anti-pinch sensor, and the anti-pinch sensor is electrically connected to the control switch via a controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 It is a front view of the mechanical extension structure (first structure) of the present invention in a sitting position;

[0079] Figure 2 It is a front view of the mechanical extension structure (first structure) in the present invention in the TV posture position;

[0080] Figure 3 It is a front view of the mechanical extension structure (first structure) in the present invention in a lying position;

[0081] Figure 4 is a three-dimensional diagram of the mechanical extension structure (first structure) of the present invention in a lying position;

[0082] Figure 5 It is a schematic diagram of the structure of the control switch and the external power supply in the present invention;

[0083] Figure 6 It is a structural schematic diagram of the control switch and the battery in the present invention;

[0084] Figure 7 is a circuit connection diagram of the seat unit in the present invention;

[0085] Figure 8 It is a front view of the mechanical extension structure (second structure) in the present invention in a lying position;

[0086] Fig. 9 is a front view of the seat unit of the present invention (the mechanical extension structure is in a sitting position);

[0087] Fig.10 is a three-dimensional diagram of the mechanical extension structure (first structure) of the present invention in a sitting position;

[0088] Fig.11 is a stereoscopic diagram of the mechanical extension structure (first structure) in the present invention in a TV posture;

[0089] Fig.12 is a three-dimensional diagram of the mechanical extension structure (first structure) of the present invention in a sitting position;

[0090] Fig.13 It is a three-dimensional diagram of a part of the swing mechanism (first structure) in the present invention;

[0091] Fig.14 It is a three-dimensional diagram of the swing mechanism (first structure) in the present invention;

[0092] Fig.15 It is a three-dimensional diagram of the swing mechanism (second structure) in the present invention;

[0093] Fig.16 It is a stereoscopic view of the backrest assembly (third structure) in the present invention. DETAILED DESCRIPTION

[0094] The present invention is further described in detail below through specific implementation examples and in conjunction with the accompanying drawings:

[0095] like Figure 1 and Figure 4As shown, the present invention discloses a mechanical extension structure 100 including a base 3, a base 1, a backrest assembly 2, a leg assembly 5, a swing mechanism 4 and a driving device 6, wherein the base 1 and the base 3 are movably connected via the swing mechanism 4, the leg assembly 5 is movably arranged in front of the base 1, the backrest assembly 2 is movably arranged at the rear of the base 1, and the driving device 6 is arranged at the base 3;

[0096] like Figure 1 and Figure 3 As shown, the mechanical extension structure 100 has a sitting position and a lying position. When the mechanical extension structure 100 is transformed from the sitting position to the lying position, the driving device 6 drives the base 1 and the swing mechanism 4 to move forward through the leg assembly 5, and the leg assembly 5 is extended in front of the base 1, and the backrest assembly 2 is tilted back relative to the base 1; when the mechanical extension structure 100 is transformed from the lying position to the sitting position, the driving device 6 drives the base 1 and the swing mechanism 4 to move backward through the leg assembly 5, and the leg assembly 5 is folded under the base 1, and the backrest assembly 2 is returned to the normal position relative to the base 1;

[0097] like Figure 5 and Figure 6 As shown, the mechanical extension structure 100 also includes a control switch 7, which includes two switch keys and a switch base (not marked). The switch base is provided with a first common terminal 751, a second common terminal 754, a first normally closed terminal 753, a second normally closed terminal 756, a first normally open terminal 752, and a second normally open terminal 755. Each switch key includes a first switch key 71 and a second switch key 73. The first switch key 71 connects the first common terminal 751 with the first normally closed terminal 753, or the first switch key 71 connects the first common terminal 751 with the first normally open terminal 752; the second switch key 73 connects the second common terminal 754 with the second normally closed terminal 756, and the second switch key 73 connects the second common terminal 754 with the second normally open terminal 755.

[0098] Among them, the second common terminal 754 is electrically connected to the positive pole of the driving device 6, the first common terminal 751 is electrically connected to the negative pole of the driving device 6, the first normally closed terminal 753 and the second normally closed terminal 756 are both connected to the negative pole of the power supply 86, the first normally open terminal 752 and the second normally open terminal 755 are both connected to the positive pole of the power supply 86, and when the mechanical extension structure 100 changes from a sitting position to a lying position, the second switch key 73 connects the second common terminal 754 and the second normally open terminal 755, and the first switch key 71 connects the first common terminal 751 and the first normally closed terminal 753; when the mechanical extension structure 100 changes from a lying position to a sitting position, the first switch key 71 connects the first common terminal 751 and the first normally open terminal 752, and the second switch key 73 connects the second common terminal 754 and the second normally closed terminal 756.

[0099] like Figure 5 and Figure 6As shown, the first switch key 71 and the second switch key 73 can realize the drive device 6 controlling the mechanical extension structure 100 to switch back and forth between the sitting position and the lying position through six electrical connection lines, and the six electrical connection lines include: the second common end 754 is electrically connected to the positive pole of the drive device 6 through the first electrical connection line, the first common end 751 is electrically connected to the negative pole of the drive device 6 through the second electrical connection line, the first normally closed end 753 is electrically connected to the second normally closed end 756 through the third electrical connection line, the first normally closed end 753 is electrically connected to the negative pole of the power supply 86 through the fourth electrical connection line, the first normally open end 752 is electrically connected to the second normally open end 755 through the fifth electrical connection line, and the second normally open end 755 is electrically connected to the positive pole of the power supply 86 through the sixth electrical connection line. This structure simplifies the circuit in the control switch 7 and reduces the manufacturing cost of the control switch 7.

[0100] Preferably, the control switch 7 includes a first reaction spring 72 and a second reaction spring 74, the first switch key 71 is arranged on the switch seat and can abut the switch seat, the first reaction spring 72 is clamped between the first switch key 71 and the switch seat, when the first reaction spring 72 releases the elastic force to push the first switch key 71 to abut the switch seat, the first switch key 71 connects the first common end 751 and the first normally closed end 753; when the first switch key 71 squeezes the first reaction spring 72 and separates from the switch seat, the first switch key 71 connects the first common end 751 and the first normally open end 752. Similarly, the second switch key 73 is arranged on the switch seat and can abut the switch seat, and the second reaction force spring clamp 74 is held between the second switch key 73 and the switch seat. When the second reaction force spring 74 releases the elastic force to push the second switch key 73 to abut the switch seat, the second switch key 73 connects the second common end 754 and the second normally closed end 756; when the second switch key 73 squeezes the second reaction force spring 74 and separates from the switch seat, the second switch key 73 connects the second common end 754 and the second normally open end 755.

[0101] The first reaction spring 72 and the second reaction spring 74 can automatically cut off the power supply of the driving device 6 by their own elastic force, that is, the first reaction spring 72 and the second reaction spring 74 use the mechanical structure to increase the safety of the control switch 7 during operation.

[0102] like Figure 5 and Figure 7 As shown, the power supply 86 includes an external power supply 861, and the first normally open terminal 752 and the second normally open terminal 755 are electrically connected to the positive electrode of the external power supply 861 through a voltage converter 862;

[0103] Of course, in this embodiment, if Figure 6 As shown, the power supply 86 may also include a battery, and the first normally open terminal 752 and the second normally open terminal 755 are electrically connected to the positive electrode of the battery 83 respectively.

[0104] The voltage between the live wire and the neutral wire of domestic electricity is usually 220V, but the voltage of the drive device 6 (the input voltage of the drive device is usually around 24V) does not need to be so high. Therefore, the first normally open end 752 and the second normally open end 755 need to be connected to the external power supply 861 through the voltage converter 862.

[0105] When the power supply 86 is a battery 83, the mechanical extension structure 100 can achieve the conversion between the sitting position and the lying position without connecting to an external power source.

[0106] like Figure 7 As shown, when the power supply 86 includes an external power supply 861 and a battery 83, the mechanical extension structure 100 also includes a controller 81, a protection switch 82 and a sensor 85. The positive pole of the battery 83 is electrically connected to the controller 81 through the sensor 85, the battery 83 is connected to the external power supply 861 through the protection switch 82, and the controller 81 is electrically connected to the protection switch 82 and is used to connect or disconnect the circuit between the battery 83 and the external power supply 861.

[0107] The controller 81 may be an MCU, a CPU, or a microprocessor unit.

[0108] According to the prior art, it is known that the charging voltage of a battery 83 with a storage capacity of 50%, the charging voltage of a battery 83 with a storage capacity of 80%, and the charging voltage of a battery 83 with a storage capacity of 95% are different; the charging current of a battery 83 with a storage capacity of 50%, the charging current of a battery 83 with a storage capacity of 80%, and the charging current of a battery 83 with a storage capacity of 95% are different.

[0109] Therefore, in this embodiment, the sensor 85 can be a voltage sensor, and the controller 81 obtains the real-time charging voltage of the positive electrode of the battery 83 through the sensor 85; since the charging voltage of the battery 83 is different at different storage capacities, the controller 81 obtains the real-time charging voltage of the positive electrode of the battery 83 through the sensor 85, so as to enable the controller 81 to monitor the storage capacities of the battery 83.

[0110] Similarly, the sensor 85 may also be a current sensor, and the controller 81 obtains the real-time charging current of the positive electrode of the battery 83 through the sensor 85. Since the charging current of the battery 83 is different at different storage capacities, the controller 81 obtains the real-time charging current of the positive electrode of the battery 83 through the sensor 85, so that the controller 81 can monitor the storage capacities of the battery 83.

[0111] Since the battery 83 is connected to the external power supply 861 through the protection switch 82, after the controller 81 obtains that the storage capacity of the battery 83 has reached a preset maximum storage capacity, the controller 81 disconnects the circuit between the battery 83 and the external power supply 861 through the protection switch 82; after the controller 81 obtains that the storage capacity of the battery 83 has reached a preset minimum storage capacity, the controller 81 connects the circuit between the battery 83 and the external power supply 861 through the protection switch 82.

[0112] Preferably, the driving device 6 is electrically connected to the external power supply 861 via one of a transistor, a MOS tube, and a relay, and the controller 81 is electrically connected to one of the transistor, the MOS tube, and the relay.

[0113] One of the transistor, MOS tube, and relay is used to connect or disconnect the circuit between the driving device 6 and the external power supply 861.

[0114] Taking the transistor as an example, the controller 81 can be electrically connected to the touch screen. When the controller 81 is electrically connected to the touch screen and the drive device 6 is electrically connected to the external power supply 861 through the transistor, the touch screen changes the state of the transistor through the controller 81 to connect or disconnect the circuit between the drive device 6 and the external power supply 861.

[0115] In addition, the drive device and the external power supply can also be electrically connected via a micro switch.

[0116] like Figure 7 As shown, the mechanical extension structure 100 further includes a controller 81 and a wireless signal receiving module 84 , and the wireless signal receiving module 84 is electrically connected to the control switch 7 through the controller 81 .

[0117] When the mechanical extension structure 100 also includes a controller 81 and a wireless signal receiving module 84, the control switch 7 includes one or more of a transistor, a MOS tube, and a relay. After the wireless signal receiving module 84 receives a control signal from a remote control device (for example, a mobile phone, a tablet computer, a remote control), the control signal is transmitted to the controller 81. The controller 81 controls the switch 7 to enable the drive device 6 to control the mechanical extension structure 100 to switch back and forth between a sitting position and a lying position.

[0118] Preferably, at least one charging socket is arranged on the switch seat, and a Type-C interface is provided on the charging socket.

[0119] Mobile phones and tablets can be connected to the Type-C interface via a data cable, so that users can charge their phones or tablets while sitting in the seat unit.

[0120] like Figure 1 , Figure 3 and Fig. 9As shown, the seat unit includes the mechanical extension structure 100 described in this embodiment, the leg assembly 5 includes a main leg rest mounting plate 51, a front leg rest rotating plate 53, a rear leg rest rotating plate 54, a front leg rest connecting plate 55 and a rear leg rest connecting plate 56, one end of the front leg rest rotating plate 53 and one end of the rear leg rest rotating plate 54 are respectively rotatably connected to the main leg rest mounting plate 51, the other end of the front leg rest rotating plate 53 is rotatably connected to one end of the front leg rest connecting plate 55, the other end of the rear leg rest rotating plate 54 is rotatably connected to one end of the rear leg rest connecting plate 56, and the other end of the front leg rest connecting plate 55 and the other end of the rear leg rest connecting plate 56 are respectively rotatably connected to the base 1;

[0121] One of the rear leg rest rotating plate 54 and the front leg rest connecting plate 55 is provided with a leg support mechanism 541. When the mechanical extension structure 100 is in a lying position, the leg support mechanism 541 abuts against the other one. Figure 4 It can be seen that in this embodiment, the leg support mechanism 541 is arranged on the rear leg rest rotating plate 54 , and when the mechanical extension structure 100 is in the lying position, the leg support mechanism 541 abuts against the front leg rest connecting plate 55 .

[0122] When the mechanical extension structure 100 is in a lying position and the leg support mechanism 541 abuts against one of the rear leg rest rotating plate 54 and the front leg rest connecting plate 55, the user (or maintenance personnel) can remove the driving device 6; during the process of the user removing the driving device 6, since the leg support mechanism 541 abuts against one of the rear leg rest rotating plate 54 and the front leg rest connecting plate 55, the shape of the leg assembly 5 will hardly change, that is, the main footrest structure will not hit the user during the process of the user removing the driving device 6.

[0123] In addition, when the mechanical extension structure 100 is in the lying position, the user can remove the driving device 6. This structure can effectively reduce the difficulty of repairing the seat unit.

[0124] The seat unit also includes a backrest structure 200 and an armrest structure (unmarked). The backrest assembly 2 can be movably arranged on the backrest structure 200. The armrest structure includes an armrest frame (unmarked). The armrest frame is the prior art, that is, the armrest frame includes two side armrest panels and a rear armrest panel. The base 3 is fixedly connected to the side armrest panels. The two side armrest panels are fixedly connected through the rear armrest panel. When the mechanical extension structure 100 is in a lying position, the interval distance between the rear armrest panel and the backrest structure 200 is ≥10cm.

[0125] The width of the user's arm is usually around 10 cm. Therefore, when the mechanical extension structure 100 is in a lying position and the distance between the rear armrest plate and the backrest structure 200 is ≥ 10 cm, the user's arm can be extended into the armrest frame through the gap between the backrest structure 200 and the rear armrest plate to realize the disassembly and assembly of the drive device 6.

[0126] Preferably, the seat unit also includes a main legrest structure (not marked), which includes a main legrest board and a main legrest decorative cover. The main legrest board is fixedly connected to the main legrest mounting plate 51, and the main legrest decorative cover is detachably provided on the main legrest board.

[0127] In the prior art, the main legrest decorative cover is installed on the main legrest board in a semi-permanent manner, for example, the main legrest decorative cover is fixed on the main legrest board by nails of a pneumatic gun; or, the main legrest decorative cover is fixed on the main legrest board by hammering nails with a hammer. This makes the main legrest structure assembly speed slow and the manufacturing cost high.

[0128] When the main legrest decorative cover is detachably arranged on the main legrest board, the main legrest decorative cover can be installed on the main legrest board without the aid of external tools; the main legrest decorative cover can also be removed from the main legrest board without the aid of external tools.

[0129] The auxiliary leg rest structure is the same as the main leg rest structure, so it will not be described in detail.

[0130] Preferably, the main footrest decorative cover is hung on the main legrest board; or, the main footrest decorative cover is provided with a first opening, the main legrest board is placed into the main footrest decorative cover through the first opening, and the main footrest decorative cover is provided with a first sealing structure at the first opening, and the first sealing structure includes one of a first linear zipper, a first arc zipper and a first buckle structure.

[0131] When the main leg rest decorative cover is provided with the first opening, the first opening can increase the deformation dimension of the main leg rest decorative cover, so as to reduce the difficulty of the main leg rest board entering the main leg rest decorative cover.

[0132] The first straight zipper, the first arc zipper and the first buckle structure are all prior art, so the above structures will not be described in detail; the first sealing structure adopts the first straight zipper, which has the advantages of simple structure and low cost; the first sealing structure adopts the first arc zipper, which has the advantage of easy disassembly and assembly of the main legrest; the first buckle structure has the advantage that the sealing structure is not easy to open, and the first buckle structure includes a clamp and a fastener, the clamp is arranged on one side of the main legrest decorative cover located at the first opening, and the fastener is arranged on the other side of the main legrest decorative cover located at the first opening. Of course, the first sealing structure can facilitate the replacement of the footrest decorative cover and the cleaning of the footrest decorative cover.

[0133] The width of the first arc-shaped zipper is greater than the width of the main legrest board, which enables the first arc-shaped zipper to further increase the size of the first opening that can be deformed. This structure further reduces the probability of the first opening being damaged during the installation of the main legrest board.

[0134] like Figure 3 and Fig.10As shown, one structure of the leg assembly 5 further includes an auxiliary leg rest mounting plate 52 and a rear leg rest extension plate 58, one end of the main leg rest mounting plate 51 and the rear leg rest extension plate 58 are respectively rotatably connected to the auxiliary leg rest mounting plate 52, and the other end of the rear leg rest extension plate 58 is rotatably connected to one end of the front leg rest rotating plate 53;

[0135] like Figure 8 As shown, another structure of the leg assembly 5 further includes an auxiliary legrest mounting plate 52, a front legrest extension plate 57, a rear legrest extension plate 58 and a control rod 59, one end of the front legrest extension plate 57 and one end of the rear legrest extension plate 58 are respectively rotatably connected to the auxiliary legrest mounting plate 52, the other end of the front legrest extension plate 57 and the other end of the rear legrest extension plate 58 are respectively rotatably connected to the main legrest mounting plate 51, one of the front legrest extension plate 57 and the rear legrest extension plate 58 is rotatably connected to one end of the control rod 59, and the other end of the control rod 59 is rotatably connected to one end of the front legrest rotating plate 53. In this embodiment, the rear legrest extension plate 58 is rotatably connected to one end of the control rod 59.

[0136] The control rod 59 is used to control the movement posture of the auxiliary leg rest mounting plate 52 .

[0137] Preferably, the seat unit further comprises an auxiliary legrest structure, which comprises an auxiliary legrest plate and an auxiliary legrest decorative cover, wherein the auxiliary legrest plate is fixedly connected to the auxiliary legrest mounting plate 52, and the auxiliary legrest decorative cover is detachably arranged on the auxiliary legrest plate.

[0138] Preferably, the auxiliary footrest decorative cover is hung on the auxiliary legrest board; or, the auxiliary footrest decorative cover is provided with a second opening, the auxiliary legrest board is placed into the auxiliary footrest decorative cover through the second opening, and the auxiliary footrest decorative cover is provided with a second sealing structure at the second opening, and the second sealing structure includes one of a second linear zipper, a second arc zipper and a second snap structure.

[0139] The width of the second arc-shaped zipper is greater than the width of the auxiliary legrest, so that the second arc-shaped zipper further increases the size of the second opening that can be deformed. This structure further reduces the probability of the second opening being damaged during the installation of the auxiliary legrest.

[0140] In this embodiment, when the seat unit includes a main legrest structure, the main legrest plate is made of plastic, and the main legrest plate is fixedly connected to the main legrest mounting plate 51 by screws or rivets; when the seat unit includes an auxiliary legrest structure, the auxiliary legrest plate is made of plastic, and the auxiliary legrest plate is fixedly connected to the auxiliary legrest mounting plate 52 by screws or rivets.

[0141] The main legrest (auxiliary legrest) made of plastic is used to reduce the weight that the leg assembly 5 needs to bear. This structure not only increases the service life of the seat unit, but also reduces the difficulty of carrying the seat unit.

[0142] When the main footrest decorative cover is hung on the main legrest board, the main footrest decorative cover is removed from the main legrest board to facilitate cleaning of the main footrest decorative cover.

[0143] The main legrest made of plastic is easy to shape, that is, the main legrest can be provided with a hook or a hanging ring for hanging the main footrest decorative cover by blow molding or extrusion molding. In addition, the main legrest made of plastic has another advantage, that is, the hook or the hanging ring can be formed by the concave of the main legrest, and this structure can effectively increase the regularity of the outer contour of the main legrest, and prevent the main footrest from damaging the user experience of the seat unit.

[0144] Preferably, a main legrest filler is provided in the main legrest decorative cover, and when the main legrest decorative cover is detachably provided on the main legrest board, the main legrest filler is clamped between the main legrest decorative cover and the main legrest board. The main legrest filler is used to increase the comfort of the user when resting his legs.

[0145] like Fig.13 and Fig.14 As shown, the first structure of the swing mechanism 4 includes a first connecting rod 41, a second connecting rod 42, a third connecting rod 43, a first swing rod 45, a second swing rod 44, a third swing rod 47, a fourth swing rod 46, a first support rod 48 and a second support rod 49, one end of the first support rod 48 and one end of the second support rod 49 are respectively rotatably connected to the base 1, the other end of the first support rod 48 and the other end of the second support rod 49 are respectively rotatably connected to the third connecting rod 43, and the other end of the first swing rod 45 and the other end of the third swing rod 47 are respectively rotatably connected to the base 1. The base 3 is rotatably connected, the other end of the second swing rod 44 and the other end of the fourth swing rod 46 are rotatably connected to the third link 43 respectively, one end of the second swing rod 44 is rotatably connected to the first swing rod 45, one end of the fourth swing rod 46 is rotatably connected to the third swing rod 47, one end of the first link 41 is rotatably connected to one end of the first swing rod 45, the other end of the first link 41 is rotatably connected to the third swing rod 47, one end of the second link 42 is rotatably connected to the first link 41, and the other end of the second link 42 is rotatably connected to the fourth swing rod 46.

[0146] When the mechanical extension structure 100 is in the sitting position, since one end of the second swing rod 44 is rotatably connected to the first swing rod 45 and the other end of the first swing rod 45 is located in front of the other end of the second swing rod 44, the second swing rod 44 and the first swing rod 45 form a support structure shaped like a "human" character; similarly, since one end of the fourth swing rod 46 is rotatably connected to the third swing rod 47 and the other end of the third swing rod 47 is located in front of the other end of the fourth swing rod 46, the fourth swing rod 46 and the third swing rod 47 also form a support structure shaped like a "human" character. The "human"-shaped support structure has a relatively stable supporting function.

[0147] In addition, when the mechanical extension structure 100 is in the lying position, the other end of the first rocker arm 45 is located behind the other end of the second rocker arm 44, and the other end of the third rocker arm 47 is located behind the other end of the fourth rocker arm 46; in the process of the mechanical extension structure 100 changing from the sitting position to the lying position, the other end of the second rocker arm 44 moves from behind the other end of the first rocker arm 45 to the front of the other end of the first rocker arm 45, and the other end of the fourth rocker arm 46 moves from behind the other end of the third rocker arm 47 to the front of the other end of the third rocker arm 47; in the process of the mechanical extension structure 100 changing from the lying position to the sitting position, the other end of the second rocker arm 44 moves from in front of the other end of the first rocker arm 45 to behind the other end of the first rocker arm 45, and the other end of the fourth rocker arm 46 moves from in front of the other end of the third rocker arm 47 to the rear of the other end of the third rocker arm 47. In this structure, the first swing rod 45 cooperates with the second swing rod 44, and the third swing rod 47 cooperates with the fourth swing rod 46 to control the forward movement distance of the third connecting rod 43. The third connecting rod 43 controls the forward movement distance of the base 1 through the first support rod 48 and the second support rod 49.

[0148] Since the other end of the second swing rod 44 and the other end of the fourth swing rod 46 are respectively rotatably connected to the third link 43, one end of the first link 41 is rotatably connected to one end of the first swing rod 45, one end of the second swing rod 44 is rotatably connected to the first swing rod 45, the other end of the first link 41 is rotatably connected to the third swing rod 47, and one end of the fourth swing rod 46 is rotatably connected to the third swing rod 47, the third link 43, the second swing rod 44, the fourth swing rod 46 and the first link 41 form a motion structure similar to a quadrilateral; as is known to all, a quadrilateral The structure has the disadvantage of uncertain motion posture. Therefore, the swing mechanism 4 controls the motion posture of the third swing rod 47 and the fourth swing rod 46 through the second connecting rod 42 (one end of the second connecting rod 42 is rotationally connected to the first connecting rod 41, and the other end of the second connecting rod 42 is rotationally connected to the fourth swing rod 46), and then controls the motion posture of the first swing rod 45 and the second swing rod 44; wherein, the other end of the second connecting rod 42 is mainly used to control the motion posture of the fourth swing rod 46, and the other end of the first connecting rod 41 is mainly used to control the motion posture of the third swing rod 47.

[0149] In addition, the second connecting rod 42 can also increase the anti-deformation capability of the fourth swing rod 46 .

[0150] like Fig.15As shown, the second structure of the swing mechanism 4 includes a first connecting rod 41, a second connecting rod 42, a third connecting rod 43, a first swing rod 45, a second swing rod 44, a third swing rod 47, a fourth swing rod 46, a first support rod 48 and a second support rod 49, one end of the first support rod 48 and one end of the second support rod 49 are respectively rotatably connected to the base 1, the other end of the first support rod 48 and the other end of the second support rod 49 are respectively rotatably connected to the third connecting rod 43, and the other end of the first swing rod 45 and the other end of the third swing rod 47 are respectively rotatably connected to the base 1. The base 3 is rotatably connected, the other end of the second swing rod 44 and the other end of the fourth swing rod 46 are rotatably connected to the third connecting rod 43 respectively, one end of the second swing rod 44 is rotatably connected to the first swing rod 45, one end of the fourth swing rod 46 is rotatably connected to the third swing rod 47, the other end of the first connecting rod 41 is rotatably connected to the fourth swing rod 46, one end of the first connecting rod 41 is rotatably connected to one end of the first swing rod 45, the other end of the second connecting rod 42 is rotatably connected to the first connecting rod 41, and one end of the second connecting rod 42 is rotatably connected to the second swing rod 44. Since the other end of the second swing rod 44 and the other end of the fourth swing rod 46 are respectively rotatably connected to the third link 43, the other end of the first link 41 is rotatably connected to the fourth swing rod 46, one end of the first link 41 is rotatably connected to one end of the first swing rod 45, and one end of the second swing rod 44 is rotatably connected to the first swing rod 45, the third link 43, the second swing rod 44, the fourth swing rod 46 and the first link 41 form a motion structure similar to a quadrilateral; as is well known, the quadrilateral structure has the disadvantage of uncertain motion posture, and therefore, the swing mechanism 4 controls the motion posture of the first swing rod 45 and the second swing rod 44 through the second link 42 (the other end of the second link 42 is rotatably connected to the first link 41, and one end of the second link 42 is rotatably connected to the second swing rod 44), and then controls the motion posture of the third swing rod 47 and the fourth swing rod 46; wherein, one end of the second link 42 mainly controls the motion posture of the second swing rod 44, and one end of the first link 41 mainly controls the motion posture of the first swing rod 45. The second connecting rod 42 is used to increase the deformation resistance of the second swing rod 44. When the second connecting rod 42 is arranged on the second swing rod 44, in order to avoid interference between the second connecting rod 42 and the first connecting rod 41 and the first swing rod 45, the first swing rod 45 needs to be lengthened to realize rotational connection between one end of the second connecting rod 42 and the middle upper position of the second swing rod 44. During the transformation of the mechanical extension structure 100 from the lying position to the sitting position, the seat cushion structure 300 moves forward and upward, and the serpentine spring of the seat cushion structure 300 bends upward. Therefore, the seat cushion structure 300 has enough space for the lengthening of the first swing rod 45. In other words, the rotational connection between one end of the second connecting rod 42 and the middle upper position of the second swing rod can avoid interference between the swing mechanism 4 and the seat cushion structure 300.

[0151] Preferably, the leg assembly 5 further includes a linkage rod 65, one of the front legrest connecting plate 55 and the rear legrest connecting plate 56 is rotatably connected to one end of the linkage rod 65, and one of the first support rod 48 and the first connecting rod 41 is rotatably connected to the other end of the linkage rod 65. Fig.11 As shown, in this embodiment, the rear leg rest connecting plate 56 is rotatably connected to one end of the linkage rod 65 , and the first support rod 48 is rotatably connected to the other end of the linkage rod 65 .

[0152] During the process of the mechanical extension structure 100 changing from a sitting position to a lying position (or during the process of the mechanical extension structure 100 changing from a lying position to a sitting position), the linkage rod 65 is used to increase the movement synchronization of the swing mechanism 4 and the base 1 to avoid incoordination between the leg assembly 5 and the base 1, for example, interference between the leg assembly 5 and the base 1, increase in the distance between the leg assembly 5 and the base 1, decrease in the distance between the leg assembly 5 and the base 1, etc.

[0153] like Figure 4 As shown, the driving device 6 includes a driver 61, a driving rod 62 is provided on the driver 61, a transmission rod 63 is provided on the driving rod 62, the driver 61 is rotatably connected to the base 3, and the front legrest connecting plate 55 and / or the rear legrest connecting plate 56 are rotatably connected to the transmission rod 63. In this embodiment, the front legrest connecting plate 55 and the rear legrest connecting plate 56 are rotatably connected to the transmission rod 63.

[0154] like Figure 8 As shown, the third structure of the swing mechanism 4 includes a first support rod 48 and a second support rod 49, one end of the first support rod 48 and one end of the second support rod 49 are respectively rotatably connected to the base 1, and the other end of the first support rod 48 and the other end of the second support rod 49 are respectively rotatably connected to the base 3. When the seat unit adopts the swing mechanism 4 of the third structure, the driving device includes a driver, a screw rod, a push block and a transmission structure, the driver is fixedly connected to the base 3, the driver is provided with a driving rod fixedly connected to the screw rod, and the push block is threadedly connected to the screw rod; the transmission structure includes a first transmission rod, a second transmission rod, a third transmission rod 67 and a fourth transmission rod 66, the second transmission rod is rotatably connected to the base 1, the push block and the second transmission rod are respectively rotatably connected to the first transmission rod, the second transmission rod and the fourth transmission rod 66 are respectively rotatably connected to the third transmission rod 67, and the front legrest connecting plate 55 and / or the rear legrest connecting plate 56 are rotatably connected to the fourth transmission rod 66. In this embodiment, the front legrest connecting plate 55 is rotatably connected to the fourth transmission rod 66.

[0155] In this embodiment, the fourth structure of the swing mechanism 4 includes a swing rod and a swing channel. The swing rod is arranged on the base 3, and the swing channel is arranged on the base 1. The swing rod can be inserted into the swing channel. When the swing rod is inserted into the swing channel, the driving device 6 drives the base 1 and the swing mechanism 4 to move forward synchronously through the leg assembly 5 so that the swing rod slides along the swing channel.

[0156] Existing seat units have many defects. One of the defects of the seat units is that when the mechanical extension structure switches back and forth between the sitting position and the lying position, the user lying on the seat unit will feel that the seat unit will shake to a certain extent. Another defect of the seat unit is that the manufacturing cost of the seat unit is relatively high.

[0157] When the swing mechanism 4 adopts the first structure and the second structure, the swing mechanism 4 has a complex structure and a high manufacturing cost, but the seat unit is not prone to shaking during the process of the mechanical extension structure switching back and forth between the sitting position and the lying position; when the swing mechanism 4 adopts the third structure, the structure of the swing mechanism 4 will be greatly simplified, reducing the manufacturing cost of the seat unit; when the swing mechanism 4 adopts the fourth structure, the seat unit is not only not prone to shaking during the process of the mechanical extension structure switching back and forth between the sitting position and the lying position, but the manufacturing cost of the seat unit is also greatly reduced.

[0158] When the swing mechanism 4 adopts the fourth structure, preferably, the swing channel includes a horizontal section and / or an inclined section. When the swing channel includes a horizontal section, the horizontal section controls the horizontal sliding distance of the base 1 relative to the base 3; when the swing channel includes an inclined section, the inclined section controls the lifting height of the base 1 relative to the base 3, wherein the inclined section can be a straight section or an arc section.

[0159] like Figure 8 As shown, one of the rear leg rest rotating plate 54 and the front leg rest connecting plate 55 is provided with a lying position limiting groove 541 matched with the leg support mechanism 551. When the mechanical extension structure 100 is in the lying position, the leg support mechanism 551 is inserted into the lying position limiting groove 541 and abuts against the groove wall of the lying position limiting groove 541. In this embodiment, the leg support mechanism 551 is provided on the front leg rest connecting plate 55, and the lying position limiting groove 541 is provided on the rear leg rest rotating plate 54.

[0160] When the leg support mechanism 551 is inserted into the lying position limit slot 541 and abuts against the slot wall of the lying position limit slot 541, the lying position limit slot 541 prevents the rear leg rest rotating plate 54 from moving relative to the front leg rest connecting plate 55 through the leg support mechanism 551, so as to improve the stability of the user's legs after being placed on the main footrest structure.

[0161] Preferably, the width of the rear leg rest rotating plate 54 is greater than the width of the front leg rest rotating plate 53 , and the gap between the front leg rest rotating plate 53 and the rear leg rest rotating plate 54 is ≤5 mm.

[0162] Since the thickness of a user's finger is usually above 5 mm, the gap between the front leg rest rotating plate 53 and the rear leg rest rotating plate 54 is set to be ≤ 5 mm to further reduce the probability of the user's finger being accidentally pinched. This structure reduces or prevents the user's finger from being inserted between the front leg rest rotating plate 53 and the rear leg rest rotating plate 54 by increasing the width of the rear leg rest rotating plate 54 and reducing the gap between the front leg rest rotating plate 53 and the rear leg rest rotating plate 54.

[0163] In the prior art, a variety of seat units are disclosed, and the seat units include a leg rest structure, an armrest structure, a seat cushion structure, and a mechanical extension structure, wherein the user's buttocks can sit on the seat cushion structure, wherein the mechanical extension structure has a sitting position and a lying position, and after the mechanical extension structure is changed from the sitting position to the lying position, the user's legs can be placed on the leg rest structure. The mechanical extension structure includes a swing mechanism, a leg assembly, a base, and a pedestal, wherein the pedestal is fixedly connected to the armrest structure, the seat cushion structure is mounted above the pedestal, the leg rest structure is mounted on the leg assembly, the leg assembly is rotatably connected to the pedestal, the pedestal is connected to the pedestal through a swing mechanism, and the pedestal supports the pedestal through the swing mechanism, so that the pedestal provides support for the user's buttocks through the seat cushion structure. However, after long-term use of the existing seat units, the seat cushion structure will shake to a certain extent relative to the armrest structure.

[0164] exist Fig. 9 and Fig.12 The present invention discloses a mechanical extension structure 100 including a base 3, two bases 1 for installing a cushion structure 300, two groups of leg assemblies 5 for installing a legrest structure, two groups of backrest assemblies 2 for installing a backrest structure 200, two groups of swing mechanisms 4 and a driving device 6, the driving device 6 is arranged on the base 3, each group of leg assemblies 5 is rotatably connected to a base 1, each base 1 is movably connected to the base 3 through a group of swing mechanisms 4, and each base 1 is also connected to the base 3 through a group of backrest assemblies 2;

[0165] During the process of the mechanical extension structure 100 changing from a sitting position to a lying position, the driving device 6 drives the base 1 and the swing mechanism 4 to move forward through the leg assembly 5, and extends the leg assembly 5 in front of the base 1; during the process of the mechanical extension structure 100 changing from a lying position to a sitting position, the driving device 6 drives the base 1 and the swing mechanism 4 to move backward through the leg assembly 5, and retracts the leg assembly 5 under the base 1. The mechanical extension structure 100 also includes at least one sitting support component 311, which is fixedly connected to the base 3. When the mechanical extension structure 100 is in the sitting position, the sitting support component 311 supports the swing mechanism 4; when the mechanical extension structure 100 is in the lying position, the sitting support component 311 is separated from the swing mechanism 4.

[0166] The base 3 can be fixedly connected to the armrest structure (not marked). In the prior art, the armrest structure will not move with the mechanical extension structure 100. Therefore, when the sitting support component 311 is fixedly connected to the base 3, the armrest structure prevents the sitting support component 311 from moving with the mechanical extension structure 100 through the base 3.

[0167] Of course, some existing seat units are armless structures. The seat units without armrest structures are provided with four flexible support rods under the base, that is, the support function of the armrest structure for the seat unit is replaced by the flexible support rods.

[0168] When the sitting posture support component 311 is located below the swing mechanism 4 and the sitting posture support component 311 abuts against the swing mechanism 4, the upper part of the sitting posture support component 311 supports the swing mechanism 4; since the base 1 is connected to the base 3 through the swing mechanism 4, when the mechanical extension structure 100 is in the sitting position and the sitting posture support component 311 is used to support the swing mechanism 4, the sitting posture support component 311 will support the base 1 through the swing mechanism 4. When the user sits on the seat cushion structure 300, the user's buttocks apply gravity to the base 1 through the seat cushion structure 300; the sitting posture support component 311 will support the base 1 through the swing mechanism 4, so that the base 1 provides support force for the seat cushion structure 300; this structure prevents the seat cushion structure 300 from moving relative to the armrest structure when the user sits on the seat cushion structure 300.

[0169] During the process of the mechanical extension structure 100 changing from a sitting position to a lying position, the driving device 6 drives the base 1 and the swing mechanism 4 to move forward through the leg assembly 5. Since the armrest structure prevents the sitting support component 311 from moving with the mechanical extension structure 100 through the base 3, after the driving device 6 drives the swing mechanism 4 to move forward through the leg assembly 5, the sitting support component 311 is separated from the swing mechanism 4.

[0170] Among them, "the driving device 6 drives the base 1 and the swing mechanism 4 to move forward through the leg assembly 5" can be that the driving device 6 directly drives the swing mechanism 4 to move forward through the leg assembly 5, and "the driving device 6 drives the base 1 and the swing mechanism 4 to move forward through the leg assembly 5" can also be that the driving device 6 indirectly drives the swing mechanism 4 to move forward through the leg assembly 5. For example, the driving device 6 drives the base 1 to move forward through the leg assembly 5, and the base 1 drives the swing mechanism 4 to move forward.

[0171] During the process of the mechanical extension structure 100 changing from a lying position to a sitting position, the driving device 6 drives the base 1 and the swing mechanism 4 to move backward through the leg assembly 5. Since the armrest structure prevents the sitting support component 311 from moving with the mechanical extension structure 100 through the base 3, after the driving device 6 drives the swing mechanism 4 to move backward through the leg assembly 5, the sitting support component 311 can abut against the swing mechanism 4.

[0172] like Fig.13 As shown, the sitting posture support component 311 includes a sitting posture support rod, the hardness of the sitting posture support rod is different from that of the swing mechanism 4, the sitting posture support rod is fixedly connected to the base 3, when the mechanical extension structure 100 is in the sitting position, the sitting posture support rod is located below the swing mechanism 4, and the sitting posture support rod abuts against the swing mechanism 4; when the mechanical extension structure 100 is in the lying position, the sitting posture support rod is separated from the swing mechanism 4.

[0173] When the sitting posture support rod abuts against the swing mechanism 4, and the hardness of the sitting posture support rod is different from that of the swing mechanism 4, one of the sitting posture support rod and the swing mechanism 4 is deformed. This structure is used to reduce the probability of bending of the sitting posture support rod and the swing mechanism 4 under the action of the extrusion force after the sitting posture support rod abuts against the swing mechanism 4; in addition, the base 3 includes two armrest plates 31, and the sitting posture support component 311 is fixedly connected to the armrest plate 31. Since the base 3 includes two armrest plates 31 and the sitting posture support component 311 is fixedly connected to the armrest plate 31, when the sitting posture support component 311 includes the sitting posture support rod and the sitting posture support rod abuts against the swing mechanism 4, the single sitting posture support rod increases its position accuracy on the armrest plate 31, so that the sitting posture support rods on the left and right sides can abut against their respective swing mechanisms 4, respectively, thereby extending the service life of all sitting posture support rods.

[0174] Preferably, the hardness of the sitting posture support rod is lower than the hardness of the swing mechanism 4. When the sitting posture support rod abuts against the swing mechanism 4 and the hardness of the sitting posture support rod is lower than that of the swing mechanism 4, the sitting posture support rod is deformed.

[0175] Of course, in other embodiments, the sitting posture support component includes a sitting posture support rod and a sitting posture support ring, the hardness of the sitting posture support ring is different from that of the swing mechanism, the sitting posture support ring is sleeved on the sitting posture support rod, and the sitting posture support rod is detachably arranged on the base, when the mechanical extension structure is in the sitting position, the sitting posture support ring is located below the swing mechanism, and the sitting posture support ring abuts the swing mechanism; when the mechanical extension structure is in the lying position, the sitting posture support ring is separated from the swing mechanism. When the sitting posture support ring abuts the swing mechanism, and the hardness of the sitting posture support ring is different from that of the swing mechanism, one of the sitting posture support ring and the swing mechanism is deformed. This structure is used to reduce the probability of bending of the sitting posture support rod (the swing mechanism applies a squeezing force to the sitting posture support rod through the sitting posture support ring) and the swing mechanism under the action of the squeezing force after the sitting posture support ring abuts the swing mechanism. In addition, the sitting posture support rod can be removed from the base, and at least one component on the sitting posture support component can be replaced.

[0176] In this embodiment, the mechanical extension structure 100 also includes at least one lying position support component 12, which is fixedly connected to the base 1. When the mechanical extension structure 100 is in a sitting position, the lying position support component 12 is separated from the swing mechanism 4; when the mechanical extension structure 100 is in a lying position, the swing mechanism 4 supports the lying position support component 12.

[0177] When the lying position support component 12 is located above the swing mechanism 4 and the lying position support component 12 abuts against the swing mechanism 4, the swing mechanism 4 supports the lower part of the lying position support component 12; since the lying position support component 12 is fixedly connected to the base 1, when the mechanical extension structure 100 is in the lying position and the swing mechanism 4 is used to support the lying position support component 12, the swing mechanism 4 supports the base 1 through the lying position support component 12. When the user's buttocks sit on the cushion structure 300, the user's buttocks apply gravity to the base 1 through the cushion structure 300; the swing mechanism 4 supports the base 1 through the lying position support component 12, so that the base 1 provides support force for the cushion structure 300; this structure prevents the cushion structure 300 from moving relative to the armrest structure when the user sits on the cushion structure 300.

[0178] When the mechanical extension structure 100 is transformed from the sitting position to the lying position, the driving device 6 drives the base 1 and the swing mechanism 4 to move forward through the leg assembly 5, wherein the base 1 moves downward relative to the swing mechanism 4. Therefore, after the driving device 6 drives the swing mechanism 4 to move forward through the leg assembly 5 and the base 1 moves downward relative to the swing mechanism 4, the lying support component 12 abuts against the swing mechanism 4. This structure reduces the height of the base 1 relative to the swing mechanism 4, thereby shortening the time required for the lying support component 12 to abut against the swing mechanism 4 and improving the reliability of the abutment between the two.

[0179] When the mechanical extension structure 100 is transformed from the lying position to the sitting position, the driving device 6 drives the base 1 and the swing mechanism 4 to move backward through the leg assembly 5, wherein the base 1 moves upward relative to the swing mechanism 4. Therefore, after the driving device 6 drives the swing mechanism 4 to move backward through the leg assembly 5 and the base 1 moves upward relative to the swing mechanism 4, the lying support component 12 is separated from the swing mechanism 4. This structure increases the time required for the lying support component 12 to separate from the swing mechanism 4 and improves the reliability of the separation of the two by raising the height of the base 1 relative to the swing mechanism 4.

[0180] like Fig.12 As shown, the lying position support component 12 includes a lying position support rod, the hardness of the lying position support rod is different from that of the swing mechanism 4, the lying position support rod is fixedly connected to the base 1, and when the mechanical extension structure 100 is in the sitting position, the lying position support rod is separated from the swing mechanism 4; when the mechanical extension structure 100 is in the lying position, the lying position support rod is located above the swing mechanism, and the lying position support rod abuts against the swing mechanism 4.

[0181] When the lying position support rod abuts against the swing mechanism 4, and the hardness of the lying position support rod is different from that of the swing mechanism 4, one of the lying position support rod and the swing mechanism 4 is deformed. This structure is used to reduce the probability of bending of the lying position support rod and the swing mechanism 4 under the action of the extrusion force after the lying position support rod abuts against the swing mechanism 4; in addition, the mechanical extension structure 100 includes two bases 1, and the lying position support rod is fixedly connected to the base 1. Since the mechanical extension structure 100 includes two bases 1 and the lying position support rod is fixedly connected to the base 1, when the lying position support component 12 includes the lying position support rod and the lying position support rod abuts against the swing mechanism 4, the single lying position support rod increases its position accuracy on the base 1, so that the lying position support rods on the left and right sides can abut against their respective swing mechanisms, respectively, thereby extending the service life of all lying position support rods.

[0182] Preferably, the hardness of the lying position support rod is lower than the hardness of the swing mechanism 4. When the lying position support rod abuts against the swing mechanism 4 and the hardness of the lying position support rod is lower than that of the swing mechanism 4, the lying position support rod is deformed.

[0183] Of course, in other embodiments, the lying position support component includes a lying position support rod and a lying position support ring, the hardness of the lying position support ring is different from that of the swing mechanism, the lying position support ring is sleeved on the lying position support rod, and the lying position support rod is detachably arranged on the base, and when the mechanical extension structure is in the sitting position, the lying position support ring is separated from the swing mechanism; when the mechanical extension structure is in the lying position, the lying position support ring is located above the swing mechanism, and the lying position support ring abuts the swing mechanism. When the lying position support ring abuts the swing mechanism, and the hardness of the lying position support ring is different from that of the swing mechanism, one of the lying position support ring and the swing mechanism is deformed. This structure is used to reduce the probability of bending of the lying position support rod (the swing mechanism applies an extrusion force to the lying position support rod through the lying position support ring) and the swing mechanism under the action of the extrusion force after the lying position support ring abuts the swing mechanism. In addition, the lying position support rod is removed from the base, and at least one component on the lying position support component can be replaced.

[0184] In this embodiment, when the mechanical extension structure is in the TV posture, the leg assembly 5 extends in front of the base 1, the sitting support component 311 is located below the swing mechanism 4, the sitting support component 311 abuts against the swing mechanism 4, and the lying support component 12 is separated from the swing mechanism 4.

[0185] When the user's buttocks sit on the seat unit with the mechanical extension structure 100 in the TV posture position, the gravity of the user's buttocks is mainly applied to the base 1 through the seat cushion structure 300; the sitting support component 311 will support the base 1 through the swing mechanism 4 to enable the base to provide supporting force for the seat cushion structure 300; this structure prevents the seat cushion structure 300 from moving relative to the armrest structure when the user sits on the seat cushion structure 300.

[0186] In this embodiment, the mechanical extension structure 100 also includes a tension spring (unmarked), a hook (unmarked) is provided at the end of the tension spring, and a flexible silencer (unmarked) is provided on the outer wall of the hook, the hardness of the flexible silencer is less than the hardness of the hook, one end of the tension spring is hung on the swing mechanism 4 through the hook, and the other end of the tension spring is hung on the backrest assembly 2 through the hook. When one end of the tension spring is hung on the swing mechanism 4 through the hook and the other end of the tension spring is hung on the backrest assembly 2 through the hook, a flexible silencer is clamped between the hook at one end of the tension spring and the swing mechanism 4, and a flexible silencer is clamped between the hook at the other end of the tension spring and the backrest assembly 2.

[0187] In other embodiments, the mechanical extension structure also includes a tension spring, a hook is provided at the end of the tension spring, a flexible silencer is provided on the outer wall of the hook, the hardness of the flexible silencer is less than the hardness of the hook, one end of the tension spring is hung on the swing mechanism through the hook, and the other end of the tension spring is hung on the base through the hook. When one end of the tension spring is hung on the swing mechanism through the hook and the other end of the tension spring is hung on the base through the hook, a flexible silencer is clamped between the hook at one end of the tension spring and the swing mechanism, and a flexible silencer is clamped between the hook at the other end of the tension spring and the base.

[0188] Preferably, when the mechanical extension structure 100 is in a sitting position, the tension spring undergoes elastic deformation and is in a stretched state; when the mechanical extension structure 100 is in a lying position, the tension spring undergoes elastic deformation and is in a stretched state; the axial length of the tension spring in the lying position is greater than the axial length of the tension spring in the sitting position.

[0189] The tension spring applies a force to the swing mechanism 4 to increase the stability of the swing mechanism 4 when the mechanical extension structure 100 is in a sitting position or a lying position; when the mechanical extension structure 100 is in a lying position, the user places his legs on the leg rest structure. At this time, the leg rest structure transfers more gravity to the swing mechanism 4 through the leg assembly 5. Therefore, the axial length of the tension spring in the lying position is greater than the axial length of the tension spring in the sitting position, so that the tension spring maintains the stability of the swing mechanism 4 through its own greater tension.

[0190] More preferably, when the mechanical extension structure 100 is in the TV posture position, the tension spring does not undergo elastic deformation; the axial length of the tension spring in the lying position is greater than the axial length of the tension spring in the sitting position, and the axial length of the tension spring in the sitting position is greater than the axial length of the tension spring in the TV posture position.

[0191] Since the sitting position is the most commonly used posture of the mechanical extension structure of the seat unit, when the mechanical extension structure is in the sitting position and the tension spring undergoes elastic deformation and is in a stretched state, the tension spring can maintain the stability of the swing mechanism 4 for a long time through its own tension, so as to avoid the seat cushion structure 300 from moving relative to the armrest structure when the user sits on the seat cushion structure 300.

[0192] like Fig.13 As shown, when the first swing mechanism 4 is adopted, the mechanical extension structure 100 also includes two sitting posture supporting components 311. When the mechanical extension structure 100 is in the sitting position, the other end of the first swing rod 45 is located in front of the other end of the second swing rod 44, and the other end of the third swing rod 47 is located in front of the other end of the fourth swing rod 46. One of the sitting posture supporting components 311 is located below the first swing rod 45 and abuts against the first swing rod 45, and the other sitting posture supporting component 311 is located below the third swing rod 47 and abuts against the third swing rod 47; when the mechanical extension structure 100 is in the lying position, the other end of the first swing rod 45 is located behind the other end of the second swing rod 44, and the other end of the third swing rod 47 is located behind the other end of the fourth swing rod 46, and the first swing rod 45 and the third swing rod 47 are both separated from their corresponding sitting posture supporting components 311.

[0193] When the mechanical extension structure 100 is in a lying position, the other end of the first rocker arm 45 is located behind the other end of the second rocker arm 44, and the other end of the third rocker arm 47 is located behind the other end of the fourth rocker arm 46, one of the sitting support components 311 is separated from the first rocker arm 45, and the other sitting support component 311 is separated from the third rocker arm 47.

[0194] The user usually adjusts the mechanical extension structure 100 of the seat unit to a lying position during recreation time, and the seat unit is in a sitting position most of the time. Therefore, the mechanical extension structure 100 can provide more stable support for the swing mechanism 4 through the two sitting support components 311.

[0195] like Fig.13 As shown, the first rocker arm 45 is provided with a front sitting posture limit groove 451 which is recessed inwardly, and the third rocker arm 47 is provided with a rear sitting posture limit groove 471 which is recessed inwardly. When the mechanical extension structure 100 is in the sitting position, one of the sitting posture support components 311 is inserted into the front sitting posture limit groove 451 and abuts against the groove wall of the front sitting posture limit groove 451; the other sitting posture support component 311 is inserted into the rear sitting posture limit groove 471 and abuts against the groove wall of the rear sitting posture limit groove 471.

[0196] After the swing mechanism 4 is damaged, the front sitting position limiting groove 451 limits the movement of one of the sitting position supporting parts 311, and the rear sitting position limiting groove 471 limits the movement of the other sitting position supporting part 311, thereby preventing the swing mechanism 4 from collapsing relative to the base 3. Therefore, the provision of the front sitting position limiting groove 451 and the rear sitting position limiting groove 471 is equivalent to providing an anti-deformation "stuck" structure for the swing mechanism 4 to a certain extent, so as to further prevent the seat cushion structure 300 from moving relative to the armrest structure when the user sits on the seat cushion structure 300.

[0197] In other embodiments, the first swing mechanism is adopted, and the mechanical extension structure further includes a sitting support component. When the mechanical extension structure is in the sitting position, the other end of the first swing rod is located in front of the other end of the second swing rod, the other end of the third swing rod is located in front of the other end of the fourth swing rod, and the sitting support component is located below the first swing rod and abuts against the first swing rod; when the mechanical extension structure is in the lying position, the other end of the first swing rod is located behind the other end of the second swing rod, the other end of the third swing rod is located behind the other end of the fourth swing rod, and the sitting support component is separated from the first swing rod;

[0198] Or, when the mechanical extension structure is in a sitting position, the other end of the first swing rod is located in front of the other end of the second swing rod, the other end of the third swing rod is located in front of the other end of the fourth swing rod, and the sitting support component is located below the third swing rod and the sitting support component abuts against the third swing rod; when the mechanical extension structure is in a lying position, the other end of the first swing rod is located behind the other end of the second swing rod, the other end of the third swing rod is located behind the other end of the fourth swing rod, and the sitting support component is separated from the third swing rod.

[0199] like Fig.15 As shown, when the second swing mechanism 4 is adopted, the mechanical extension structure 100 also includes a sitting posture supporting component 311. When the mechanical extension structure 100 is in the sitting position, the other end of the first swing rod 45 is located in front of the other end of the second swing rod 44, the other end of the third swing rod 47 is located in front of the other end of the fourth swing rod 46, and the sitting posture supporting component 311 is located below the first connecting rod 41, and the sitting posture supporting component 311 abuts against the second connecting rod 42; when the mechanical extension structure 100 is in the lying position, the other end of the first swing rod 45 is located behind the other end of the second swing rod 44, the other end of the third swing rod 47 is located behind the other end of the fourth swing rod 46, and the sitting posture supporting component 311 is separated from the second connecting rod 42.

[0200] In other embodiments, a second swing mechanism is adopted, and the mechanical extension structure also includes a sitting posture supporting component. When the mechanical extension structure is in a sitting position, the other end of the first swing rod is located in front of the other end of the second swing rod, and the other end of the third swing rod is located in front of the other end of the fourth swing rod, and the sitting posture supporting component is located below the first connecting rod and abuts against the first connecting rod; when the mechanical extension structure is in a lying position, the other end of the first swing rod is located behind the other end of the second swing rod, and the other end of the third swing rod is located behind the other end of the fourth swing rod, and the sitting posture supporting component is separated from the first connecting rod.

[0201] like Fig.12 As shown, the mechanical extension structure 100 also includes a lying position support component 12, which is fixedly connected to the base 1. When the mechanical extension structure 100 is in a lying position, the lying position support component 12 is located above the second support rod 49 and the lying position support component 12 abuts against the second support rod 49; when the mechanical extension structure 100 is in a sitting position, the lying position support component 12 is separated from the second support rod 49.

[0202] In other embodiments, the mechanical extension structure includes a lying position support component, when the mechanical extension structure is in the lying position, the lying position support component is located above the first support rod and abuts the first support rod; when the mechanical extension structure is in the sitting position, the lying position support component is separated from the first support rod; or, the mechanical extension structure includes two lying position support components, the two lying position support components are fixedly connected to the base, when the mechanical extension structure is in the lying position, one of the lying position support components is located above the first support rod and abuts the first support rod, and the other lying position support component is located above the second support rod and abuts the second support rod; when the mechanical extension structure is in the sitting position, one of the lying position support components is separated from the first support rod, and the other lying position support component is separated from the second support rod; the swing mechanism supports the base through the two lying position support components to reduce the probability of the base shaking.

[0203] like Fig. 9 and Fig.14 As shown, taking the upper end surface of the base 1 as the reference plane, the rotation connection between the other end of the first support rod 48 and the third link 43 is located above the rotation connection between the other end of the second swing rod 44 and the third link 43, the rotation connection between the other end of the second support rod 49 and the third link 43 is located above the rotation connection between the other end of the fourth swing rod 46 and the third link 43, and the rotation connection between the other end of the first support rod 48 and the third link 43 is located above the rotation connection between the other end of the second support rod 49 and the third link 43.

[0204] When the user's buttocks sit on the seat cushion structure 300 and the mechanical extension structure 100 is in a sitting position, the seat cushion structure 300 provides a downward force to the first support rod 48 through the base 1. Since the rotation connection between the other end of the first support rod 48 and the third link 43 is located above the rotation connection between the other end of the second swing rod 44 and the third link 43, the "rotation connection between the other end of the first support rod 48 and the third link 43" applies a downward thrust to the "rotation connection between the other end of the second swing rod 44 and the third link 43" to achieve the second swing rod 44 pulling the first swing rod 45 downward to abut against the sitting support component 311. This structure further improves the reliability of the sitting support component 311 supporting the swing mechanism 4.

[0205] When the user's buttocks sit on the seat cushion structure 300 and the mechanical extension structure 100 is in a sitting position, the seat cushion structure 300 provides a downward force for the second support rod 49 through the base 1. Since the rotation connection between the other end of the second support rod 49 and the third link 43 is located above the rotation connection between the other end of the fourth swing rod 46 and the third link 43, the "rotation connection between the other end of the second support rod 49 and the third link 43" applies a downward thrust to the "rotation connection between the other end of the fourth swing rod 46 and the third link 43" to achieve the fourth swing rod 46 pulling the third swing rod 47 downward to abut against the sitting support component 311. This structure further improves the reliability of the sitting support component 311 supporting the swing mechanism 4.

[0206] In this embodiment, the rotation connection between the other end of the first support rod 48 and the third connecting rod 43 is located above the rotation connection between the other end of the second support rod 49 and the third connecting rod 43. Figure 4 As shown, "the rotation connection between the other end of the first support rod 48 and the third connecting rod 43" is slightly higher than "the rotation connection between the other end of the second support rod 49 and the third connecting rod 43". Therefore, the swing mechanism 4 slightly raises the height of the front side of the base 1, that is, raises the height of the user's legs, so that the user has a feeling of his buttocks sinking into the seat unit and leaning back slightly.

[0207] Preferably, the second swing arm 44 is provided with a first reinforcing rib (not marked); and / or, the fourth swing arm 46 is provided with a second reinforcing rib (not marked).

[0208] The third connecting rod 43 provides a downward pulling force for the first swing rod 45 through the second swing rod 44, and therefore, the first reinforcing rib is used to increase the deformation resistance of the second swing rod 44; the third connecting rod 43 provides a downward pulling force for the third swing rod 47 through the fourth swing rod 46, and therefore, the second reinforcing rib is used to increase the deformation resistance of the fourth swing rod 46.

[0209] More preferably, when the first reinforcing rib is provided on the second swing arm 44, the sitting posture supporting component 311 is located on one side of the second swing arm 44, and the first reinforcing rib is located on the other side of the second swing arm 44; when the second reinforcing rib is provided on the fourth swing arm 46, the sitting posture supporting component 311 is located on one side of the fourth swing arm 46, and the first reinforcing rib is located on the other side of the fourth swing arm 46.

[0210] When the sitting posture supporting component 311 is located on one side of the second swing arm 44 and the first reinforcing rib is located on the other side of the second swing arm 44, the first reinforcing rib will not interfere with the sitting posture supporting component 311 during the movement of the second swing arm 44; when the sitting posture supporting component 311 is located on one side of the fourth swing arm 46 and the first reinforcing rib is located on the other side of the fourth swing arm 46, the second reinforcing rib will not interfere with the sitting posture supporting component 311 during the movement of the fourth swing arm 46.

[0211] In this embodiment, the third structure of the swing mechanism 4 includes a first support rod 48 and a second support rod 49, one end of the first support rod 48 and one end of the second support rod 49 are respectively rotatably connected to the base 1, and the other end of the first support rod 48 and the other end of the second support rod 49 are respectively rotatably connected to the base 3;

[0212] The mechanical extension structure 100 also includes at least one sitting support component 311. When the mechanical extension structure 100 is in a sitting position, the sitting support component 311 is located below the first support rod 48 and abuts against the first support rod 48; and / or the sitting support component 311 is located below the second support rod 49 and abuts against the second support rod 49; when the mechanical extension structure 100 is in a lying position, the sitting support component 311 is separated from the first support rod 48 and the second support rod 49.

[0213] Preferably, when the third swing mechanism 4 is adopted, the mechanical extension structure 100 includes two sitting posture support components 311. When one of the sitting posture support components 311 is located below the first support rod 48 and the sitting posture support component 311 abuts against the first support rod 48, one of the sitting posture support components 311 provides support force for the base 1 through the first support rod 48; when the other sitting posture support component 311 is located below the second support rod 49 and the sitting posture support component 311 abuts against the second support rod 49, the other sitting posture support component 311 provides support force for the base 1 through the second support rod 49. When the first support rod 48 cannot rotate relative to the base 3 and the second support rod 49 cannot rotate relative to the base 3, the position of the base 1 is also fixed, which will prevent the seat cushion structure 300 from moving relative to the armrest structure when the user sits on the seat cushion structure 300.

[0214] like Fig.12 As shown, the base 3 includes two armrest plates 31 and a crossbeam tube 32, and the two armrest plates 31 are directly or indirectly connected as a whole through the crossbeam tube 32; the first rocker mechanism 4, the second rocker structure 4: the first rocker 45 and the third rocker 47 are rotatably connected to the armrest plates 31 respectively, and the armrest plates 31 are fixedly connected to the armrest structure; the third rocker structure 4: the other end of the support rod 48 and the other end of the second support rod 49 are rotatably connected to the armrest plates 31 respectively.

[0215] In other embodiments, the base includes a metal frame, such as a concave metal frame, an I-shaped metal frame, a quadrilateral metal frame, an elliptical metal frame, a hexagonal metal frame, etc.; the first rocker mechanism and the second rocker structure: the first rocker and the third rocker are respectively rotatably connected to the annular metal frame, and the annular metal frame is fixedly connected to the armrest structure; the third rocker structure: the other end of the support rod and the other end of the second support rod are respectively rotatably connected to the annular metal frame.

[0216] like Figure 4and Fig.12 As shown, the driving device 6 includes a driver 61, a driving rod 62 is provided on the driver 61, the driver 61 is rotatably connected to the base 3, and the leg assembly 5 is rotatably connected to the driving rod 62. In other embodiments, the driving device includes a driver, a screw and a push block, the driver is fixedly connected to the base, the driver is provided with a driving rod fixedly connected to the screw, the push block is threadedly connected to the screw, and the leg assembly is directly or indirectly rotatably connected to the push block.

[0217] Preferably, the driver 61 is rotatably connected to the crossbeam tube 32; Fig.12 As shown, the base 3 includes two armrest boards 31 and a crossbeam tube 32 for connecting the sofa armrests. The two armrest boards 31 are directly or indirectly connected as a whole through the crossbeam tube 32, and the armrest boards 31 are fixedly connected to the armrest structure.

[0218] In the prior art, when the mechanical extension structure is transformed from a lying position to a sitting position, the driving device drives the leg assembly to move and fold it under the base. However, the leg assembly is prone to pinching the user's fingers or other parts of the body during the movement.

[0219] In this embodiment, an anti-pinch sensor (unmarked) is provided on the leg assembly 5. When the anti-pinch sensor detects that the user's body is clamped in the leg assembly 5 (or between the leg assembly 5 and the armrest structure), the anti-pinch sensor transmits the detected electrical signal to the controller 81, and then the power supply of the drive device 6 is disconnected through the controller 81, or the drive device 6 is controlled to move in the opposite direction through the controller 81; preferably, one of the rear leg rest rotating plate 54 and the front leg rest connecting plate 53 is provided with an anti-pinch sensor, and the anti-pinch sensor is electrically connected to the control switch 7 through the controller 81.

[0220] like Figure 1 As shown, the first structure of the backrest assembly 2 includes a backrest plate 21, a backrest front bracket 22, a backrest rear bracket 23 and a backrest driving rod 24, one end of the backrest front bracket 22 is rotatably connected to the backrest plate 21, the other end of the backrest front bracket 22 is rotatably connected to the base 1, one end of the backrest rear bracket 23 is rotatably connected to the backrest plate 21, the backrest rear bracket 23 is rotatably connected to the base 1, one end of the backrest driving rod 24 is rotatably connected to the other end of the backrest rear bracket 23, and the other end of the backrest driving rod 24 is rotatably connected to the base 3;

[0221] During the transformation of the mechanical extension structure 100 from the sitting position to the lying position, the backrest plate 21 moves forward.

[0222] In this embodiment, the second structure of the backrest assembly 2 includes a backrest plate 21, a front backrest bracket 22, a backrest bracket 23 and a backrest driving rod 24, one end of the front backrest bracket 22 is rotatably connected to the backrest plate 21, the other end of the front backrest bracket 22 is fixedly connected to the base 1, one end of the backrest bracket 23 is rotatably connected to the backrest plate 21, the backrest bracket 23 is rotatably connected to the base 1, one end of the backrest driving rod 24 is rotatably connected to the other end of the backrest bracket 23, and the other end of the backrest driving rod 24 is rotatably connected to the base 3;

[0223] During the transformation of the mechanical extension structure 100 from the sitting position to the lying position, the backrest plate 21 moves forward.

[0224] like Fig.16 As shown, the third structure of the backrest assembly 2 includes a backrest plate 21, a backrest front bracket 22, a backrest back bracket 23, a backrest connecting bracket 25 and a backrest driving rod 24, one end of the backrest front bracket 22 is rotatably connected to the backrest plate 21, the other end of the backrest front bracket 22 is fixedly connected to the base 1, one end of the backrest back bracket 23 is rotatably connected to the backrest plate 21, the other end of the backrest back bracket 23 is rotatably connected to one end of the backrest connecting bracket 25, the backrest connecting bracket 25 is rotatably connected to the base 1, one end of the backrest driving rod 24 is rotatably connected to the other end of the backrest connecting bracket 25, and the other end of the backrest driving rod 24 is rotatably connected to the base 3;

[0225] During the transformation of the mechanical extension structure 100 from the sitting position to the lying position, the backrest plate 21 moves forward.

[0226] Three types of backrest components 2 are used for different seat units: the first type of backrest component 2 is mainly used for seat units with zero wall leaning and zero back rubbing (in the process of the mechanical extension structure 100 changing from a sitting position to a lying position, the front backrest bracket 22 drives the backrest structure 200 to move relative to the seat cushion structure 300 through the backrest plate 21, so as to reduce the displacement difference between the backrest structure 200 and the user's back); the second type of backrest component 2 is mainly used to increase the reclining range of the backrest structure 200; the third type of backrest component 2 mainly slows down the reclining speed of the backrest structure 200 through the rear backrest bracket 23.

[0227] In the prior art, a variety of seat units are disclosed, and the seat units include a backrest structure, a cushion structure, and a mechanical extension structure. The user's buttocks can sit on the cushion structure, and the user's back can lean against the front of the backrest structure, wherein the mechanical extension structure has a sitting position and a lying position. The mechanical extension structure includes a backrest assembly, and the backrest structure is installed on the backrest assembly. In the process of the mechanical extension structure changing from the sitting position to the lying position, the backrest assembly will drive the backrest structure to lean back relative to the cushion structure; in the process of the mechanical extension structure changing from the lying position to the sitting position, the backrest assembly will drive the backrest structure to return to the seat cushion structure. However, in the process of the backrest structure moving relative to the cushion structure, the backrest assembly will also move relative to the backrest structure, which may cause the user's fingers to be pinched during the movement of the backrest assembly.

[0228] exist Fig. 9 The present invention discloses a seat unit, which includes a backrest structure 200, a seat cushion structure 300 and a mechanical extension structure 100, wherein the mechanical extension structure 100 includes a base 1 for mounting the seat cushion structure 300 and a backrest assembly 2 for mounting the backrest structure 200;

[0229] The backrest structure 200 includes a backrest frame 2001, a backrest filler 2003, a backrest decorative cover 2004 and a backrest elastic member 2002. The backrest frame 2001 is provided with a mounting member (not marked), the backrest elastic member 2002 is arranged on the backrest frame 2001, the backrest filler 2003 is arranged on the backrest decorative cover 2004, and the backrest decorative cover 2004 is arranged on the backrest frame 2001. When the backrest device cover 2004 is arranged on the backrest frame 2001, the backrest elastic member 2002 abuts against the backrest decorative cover 2004 and provides elastic support force for the backrest device cover 2004.

[0230] The seat cushion structure 300 includes a seat cushion frame 3001, a seat cushion filler 3003, a seat cushion decorative cover 3004 and a seat cushion elastic member 3002. The seat cushion elastic member 3002 is arranged on the seat cushion frame 3001, the seat cushion filler 3003 is arranged on the seat cushion decorative cover 3004, and the seat cushion decorative cover 3004 is arranged on the seat cushion frame 3001. When the seat cushion decorative cover 3004 is arranged on the seat cushion frame 3001, the seat cushion elastic member 3002 is arranged on the seat cushion frame 3001 and provides elastic support force for the seat cushion decorative cover 3004.

[0231] The backrest assembly 2 adopts the first structure, that is, the backrest assembly 2 includes a backrest plate 21, a backrest front bracket 22 and a backrest rear bracket 23, the backrest plate 21 is detachably inserted into the mounting member, one end of the backrest front bracket 22 is rotatably connected to the backrest plate 21, the other end of the backrest front bracket 22 is rotatably connected to the base 1, one end of the backrest rear bracket 23 is rotatably connected to the backrest plate 21, and the backrest rear bracket 23 is rotatably connected to the base 1;

[0232] Among them, the front backrest bracket 22 and the rear backrest bracket 23 are located within the projection of the backrest structure 200 on the horizontal plane. When the backrest board 21 is inserted into the mounting part, the front backrest bracket 22 and the backrest decorative cover 2004 respectively abut against the seat cushion decorative cover 3004. The length distance between the front face of the backrest decorative cover 2004 and the front face of the backrest frame 2001 is L11. The height dimension of the front backrest bracket 22 above the base 1 is L3. The length distance between one end face of the seat cushion decorative cover 3004 and one end face of the seat cushion frame 3001 is L21. L11 is greater than L3, and L21 is greater than L3.

[0233] In this embodiment, the seat cushion elastic member 3002 includes at least one serpentine spring (not marked) and at least one elastic band (not marked), the two ends of the serpentine spring are arranged on the seat cushion frame 3001, and the two ends of the elastic band are arranged on the seat cushion frame 3001, wherein the serpentine spring and the elastic band are arranged on the seat cushion frame 3001 in a crisscross manner;

[0234] The elastic band is located below one of the serpentine springs; or, the elastic band is stretched and arranged in the middle position of one of the serpentine springs.

[0235] The serpentine spring provides support for the cushion decoration cover 3004 and the cushion filler 3003. Since the elastic force of the elastic band is different from that of the serpentine spring, the elastic band provides secondary support for the cushion decoration cover 3004 and the cushion filler 3003 through the serpentine spring. This structure is used to increase the service life of the cushion structure 300.

[0236] The meaning of “the serpentine spring and the elastic band are arranged on the seat cushion frame 3001 in a crisscross manner” includes: one end of the serpentine spring is arranged on the front side of the seat cushion frame 3001, the other end of the serpentine spring is arranged on the rear side of the seat cushion frame 3001, one end of the elastic band is arranged on the left side of the seat cushion frame 3001, and the other end of the elastic band is arranged on the right side of the seat cushion frame 3001. In this solution, the elastic band is preferably located below one of the serpentine springs.

[0237] The meaning of “the serpentine spring and the elastic band are arranged on the seat cushion frame 3001 in a crisscross manner” also includes: one end of the serpentine spring is arranged on the front side of the seat cushion frame 3001, the other end of the serpentine spring is arranged on the rear side of the seat cushion frame 3001, and both ends of the elastic band are arranged on the left side of the seat cushion frame 3001. In this solution, it is preferred that the elastic band is arranged in the middle position of one of the serpentine springs.

[0238] Preferably, a backrest cavity is provided on the backrest frame 2001, and a mounting piece is provided on the wall of the backrest cavity of the backrest frame 2001, and the backrest board 21 is detachably inserted into the mounting piece. When the backrest board 21 is inserted into the mounting piece, since the mounting piece is located in the backrest cavity, at least a portion of the backrest board 21 is located in the backrest cavity. This structure prevents the user's fingers from extending into the gap between the backrest board 21 and the mounting piece to achieve the purpose of anti-pinching of the seat unit.

[0239] When the front backrest bracket 22 and the rear backrest bracket 23 are located within the projection of the backrest structure 200 on the horizontal plane, the backrest assembly 2 will not be exposed from the backrest structure 200. This structure reduces the probability of direct contact between the user's fingers and the backrest assembly 2 to achieve the purpose of anti-pinching of the seat unit.

[0240] When the backrest board 21 is inserted into the mounting part and the backrest decorative cover 2004 abuts against the seat cushion decorative cover 3004, it is more difficult for the user's fingers to pass through the gap between the backrest decorative cover 2004 and the seat cushion decorative cover 3004. When the backrest board 21 is inserted into the mounting part and the backrest front bracket 22 abuts against the seat cushion decorative cover 3004, it is more difficult for the user's fingers to enter the gap between the backrest front bracket 22 and the seat cushion decorative cover 3004.

[0241] In the prior art, after a user sits in a seat unit for a long time, the user's body will feel a certain degree of fatigue, which leads to a decrease in the user experience of the seat unit.

[0242] Preferably, the backrest structure 200 also includes a massager (not marked), which is located in the backrest decorative cover 2004 and is surrounded by a backrest filler 2003; wherein the backrest filler 2003 is mainly used to support the massager and to limit the position of the massager in the backrest structure 200, therefore, more preferably, the massager is fixedly connected to the backrest filler 2003.

[0243] In order to avoid affecting the massage effect of the massager, in this embodiment, the peripheral side of the massager is fixed to the backrest filler 2003, and the front side of the massager corresponds to and directly contacts the backrest decorative cover 2004.

[0244] In this embodiment, the massager is electrically connected to the power supply 86, that is, the power supply 86 provides electrical energy to the massager.

[0245] In this embodiment, the massager is electrically connected to the controller 81, that is, the controller 81 controls the vibration frequency, vibration amplitude, vibration intensity, etc. of the massager to increase the massage comfort of the massager. When the controller 81 is electrically connected to the massager, preferably, the controller 81 is arranged on the switch seat. When the controller 81 is arranged on the switch seat, all functions of the controller 81 can be integrated on the switch seat and controlled by the switch seat, that is, a button of the controller is arranged on the switch seat, and the button controls the vibration frequency, vibration amplitude, vibration intensity, etc. of the massager through the controller 81.

[0246] When L11 is greater than L3, no matter how the backrest front bracket 22 rotates relative to the base 1, the backrest front bracket 22 will not move to the front of the front of the backrest decorative cover 2004; when L21 is greater than L3, no matter how the backrest front bracket 22 rotates relative to the base 1, the backrest front bracket 22 will not move above one end surface of the seat cushion decorative cover 3004. Since the backrest front bracket 22 will not move to the front of the front of the backrest decorative cover 2004 and will not move above one end surface of the seat cushion decorative cover 3004, the backrest decorative cover 2004 and the seat cushion decorative cover 3004 have the function of preventing the user's fingers, back, and buttocks from contacting the backrest front bracket 22, so as to achieve the purpose of anti-pinch of the seat unit.

[0247] exist Fig. 9 In the embodiment, the maximum deformation distance between the front face of the backrest decorative cover 2004 and the front face of the backrest frame 2001 is L13, which is greater than L3; the maximum deformation distance between one end face of the seat cushion decorative cover 3004 and one end face of the seat cushion frame 3001 is L23, which is greater than L3.

[0248] Among them, "the maximum deformation distance between the front of the backrest decorative cover 2004 and the front of the backrest frame 2001" is the length distance between the front of the backrest decorative cover 2004 and the front of the backrest frame 2001 when the backrest filler 2003 and the backrest elastic member 2002 are compressed to the limit position. The concept that the backrest filler 2003 and the backrest elastic member 2002 are compressed to the limit position is relatively vague. Since the weight of the user usually does not exceed 100kg (1 kilogram is equal to 1kg), therefore, in this embodiment, "the maximum deformation distance between the front of the backrest decorative cover 2004 and the front of the backrest frame 2001" is the length distance between the front of the backrest decorative cover 2004 and the front of the backrest frame 2001 after the backrest filler 2003 and the backrest elastic member 2002 are squeezed by 100kg of gravity.

[0249] The backrest filling 2003 and the seat cushion filling 3003 can be one of the materials such as sponge, natural latex, down, and artificial cotton, or the backrest filling 2003 and the seat cushion filling 3003 can be multiple materials such as sponge, natural latex, down, and artificial cotton, that is, the backrest filling 2003 and the seat cushion filling 3003 can be deformed.

[0250] When L13 is greater than L3, the probability of the backrest front bracket 22 piercing the backrest decorative cover 2004 will be reduced during the rotation of the backrest front bracket 22 relative to the base 1; when L23 is greater than L3, the probability of the backrest front bracket 22 piercing the seat cushion decorative cover 3004 will be reduced during the rotation of the backrest front bracket 22 relative to the base 1. This structure makes the seat unit have an anti-pinch function and its service life will be correspondingly increased.

[0251] Preferably, after the backrest decorative cover 2004 is deformed, its position can move from the first backrest position 20051 to the second backrest position 20052, and the length distance between the front of the backrest decorative cover 2004 at the second backrest position 20052 and the front of the backrest frame 2001 is L12, and L12 is greater than L3.

[0252] When L12 is greater than L3, even if the user leans against the backrest decorative cover 2004 at the second backrest position 20052, his / her back will not contact the backrest front bracket 22; after the seat cushion decorative cover 3004 is deformed, its position can move from the first seat cushion position 30051 to the second seat cushion position 30052. When L12 is greater than L3, even if the user sits on the seat cushion decorative cover 3004 at the second seat cushion position 30052, his / her buttocks will not contact the backrest front bracket 22. Therefore, "L12 is greater than L3" further enhances the anti-pinch effect of the seat unit.

[0253] More preferably, the shortest distance between the backrest decorative cover 2004 at the backrest second position 20052 and the backrest front bracket 22 is ≥3 cm.

[0254] When the shortest distance between the backrest decorative cover 2005 and the backrest front bracket 22 is ≥3cm, the user's back will not feel the movement of the backrest front bracket 22 even if the user's back is against the backrest decorative cover 2004 at the backrest second position 20052; when the shortest distance between the backrest decorative cover 2004 at the backrest second position 20052 and the backrest front bracket 22 is ≥3cm, the user's buttocks will not feel the movement of the backrest front bracket 22 even if the user's buttocks sit on the cushion decorative cover 3004 at the cushion second position 30052. Therefore, "the shortest distance between the backrest decorative cover 2004 at the backrest second position 20052 and the backrest front bracket 22 is ≥3cm" further enhances the anti-pinch effect of the seat unit.

[0255] In the prior art, the thickness of the backrest filler 2003 and the seat cushion filler 3003 at different positions are different. Therefore, in this embodiment, when measuring values ​​such as length, distance, and shortest distance, the straight-line distance between the position of the backrest frame 2001 used for measurement and the seat cushion frame 3001 used for measurement and the front backrest bracket 22 shall not exceed 15 cm.

[0256] In the present invention, the mechanical extension structure has a sitting position, a TV position and a lying position. Figure 1 The mechanical extension structure 100 is in a sitting position, Figure 2 The mechanical extension structure 100 is in the TV posture, Figure 3 The mechanical extension structure 100 is in a lying position.

[0257] like Figure 1and Fig. 9 As shown, a limiting rod 11 is provided on the base 1. When the mechanical extension structure 100 is in a sitting position, the back of the backrest front bracket 22 abuts against the limiting rod 11; Figure 2 and Figure 3 As shown, when the mechanical extension structure 100 is transformed from the TV posture position to the lying position, the backrest plate 21 pushes the backrest front bracket 22 to rotate clockwise, so that the backrest front bracket 22 is separated from the limiting rod 11 and squeezes the seat cushion decorative cover 3004.

[0258] When the mechanical extension structure 100 is in the sitting position and the back of the front back bracket 22 abuts the limit rod 11, the limit rod 11 is used to prevent the front back bracket from rotating counterclockwise; because the limit rod 11 prevents the front back bracket 22 from rotating counterclockwise, the front back bracket 22 cannot drive the back board 21 to move away from the front back bracket 22, that is, when the mechanical extension structure 100 is in the sitting position, the front back bracket 22 cannot drive the back board 21 to continue moving. This structure is preferably used to achieve zero wall-bearing of the sofa unit.

[0259] During the transformation of the mechanical extension structure 100 from the TV posture position to the lying posture position, the backrest front bracket 22 is separated from the limiting rod 11, and the backrest front bracket 22 presses the cushion decoration cover 3004; since the cushion filler 3003 is arranged on the cushion decoration cover 3004 and the cushion filler 3003 can be deformed, during the process of the backrest front bracket 22 pressing the cushion decoration cover 3004, the cushion filler 3003 deforms itself, so that the cushion decoration cover 3004 always abuts against the backrest front bracket 22. This structure effectively prevents the user's fingers or other parts of the body from accidentally extending into the gap between the backrest front bracket 22 and the cushion decoration cover 3004 during the rotation of the backrest front bracket 22 around the base 1, so as to achieve the purpose of anti-pinch of the seat unit.

[0260] When the mechanical extension structure 100 is in the lying position, the seat cushion decoration cover 3004 and the seat cushion filler 3003 are sandwiched between the backrest front bracket 22 and the base 1. When the seat cushion decoration cover 3004 and the seat cushion filler 3003 are sandwiched between the backrest front bracket 22 and the base 1, it is difficult for the user's fingers to extend into the gap between the backrest front bracket 22 and the base 1.

[0261] Preferably, the seat cushion decoration cover 3004 is detachably provided on the seat cushion frame 3001, for example, the seat cushion decoration cover 3004 is hung on the seat cushion frame 3001, the seat cushion decoration cover 3004 is snap-connected to the seat cushion frame 3001, and the seat cushion decoration cover 3004 is connected to the seat cushion frame 3001 by screws.

[0262] Since the seat cushion decorative cover 3004 and the seat cushion filler 3003 are clamped between the front bracket 22 of the backrest and the base 1, when the seat cushion decorative cover 3004 is detachably provided on the seat cushion frame 3001, the user can remove the damaged seat cushion decorative cover 3004 (the seat cushion decorative cover 3004 is clamped by the front bracket 22 of the backrest and the base 1) and replace the new seat cushion decorative cover 3004 for the seat unit.

[0263] like Figure 3 As shown, the limiting rod 11 includes a base rod 111 and a limiting sleeve 112 which is sleeved on the base rod 111, and the base rod 111 is fixedly connected to the base 1. When the mechanical extension structure 100 changes from the sitting position to the TV position, the back of the backrest front bracket 22 abuts against the limiting sleeve 112; the hardness of the limiting sleeve 112 is different from the hardness of the backrest front bracket 22. Of course, in other embodiments, the limiting rod may also include only the base rod, and the hardness of the base rod is different from the hardness of the backrest front bracket.

[0264] When the back side of the front back support 22 abuts against the limiting sleeve 112, and the hardness of the limiting sleeve 112 is different from that of the front back support 22, there is no gap between the front back support 22 and the limiting sleeve 112. This structure can prevent the user's fingers or other parts of the body from extending into the gap between the front back support 22 and the limiting sleeve 112, so as to achieve the purpose of anti-pinching of the seat unit.

[0265] In addition, the limiting sleeve 112 can be replaced to increase the service life of the seat unit.

[0266] Preferably, the back of the backrest front bracket 22 is provided with a backrest limiting groove (not marked) matching the limiting sleeve 112. When the back of the backrest front bracket 22 abuts against the limiting sleeve 112, the limiting sleeve 112 is inserted into the backrest limiting groove and abuts against the groove wall of the backrest limiting groove. When the mechanical extension structure 100 changes from the sitting position to the TV position, the backrest limiting groove is used to prevent the limiting sleeve 112 from sliding relative to the backrest front bracket 22, so as to further improve the anti-pinch effect of the seat unit.

[0267] Preferably, the center point of the limit rod 11 is A1, the center point of the rotational connection between the other end of the front back bracket 22 and the base 1 is A2, the interval distance between A1 and A2 is L4, the width dimension of half of the front back bracket 22 is L5, and L4 is greater than L5; when the mechanical extension structure changes from the TV position to the lying position, the angle between the back of the front back bracket and the horizontal plane is less than 90°.

[0268] The center point of the rotational connection between one end of the front back bracket 22 and the back plate 21 is A3. When A2 and A3 are connected by a dotted line, the width dimension between the dotted line and the back of the front back bracket 22 is half of the front back bracket 22.

[0269] In this embodiment, when the mechanical extension structure 100 is in the sitting position, the angle between the back of the front backrest bracket 22 and the horizontal plane is less than 90°. Of course, in other embodiments, when the mechanical extension structure is in the sitting position, the angle between the back of the front backrest bracket and the horizontal plane is greater than 90°; when the mechanical extension structure is in the sitting position, and the angle between the back of the front backrest bracket and the horizontal plane is greater than 90°, the limit rod is used to support the front backrest bracket to prevent the front backrest bracket from being difficult to rotate counterclockwise relative to the base; since the backrest frame is connected to the front backrest bracket through the backrest board, when the limit rod supports the front backrest bracket, the front backrest bracket will not drive the backrest frame to move backward through the backrest board; this structure effectively increases the reliability of the backrest structure supporting the user's back when the user sits in the seat unit (the mechanical extension structure of the seat unit is in the sitting position).

[0270] like Figure 2 and Figure 3 As shown, when the mechanical extension structure 100 is transformed from the TV posture position to the lying posture position, when the angle between the back of the front backrest bracket 22 and the horizontal plane is less than 90°, the front backrest bracket 22 rotates clockwise and inevitably moves away from the limiting rod 11. This structure prevents the limiting rod 11 from interfering with the rotation of the front backrest bracket 22.

[0271] In this embodiment, the backrest assembly 2 further includes a backrest driving rod 24, one end of which is rotatably connected to the other end of the backrest bracket 23, and the mechanical extension structure 100 further includes a base 3, which is located below the base 1, and the other end of the backrest driving rod 24 is rotatably connected to the base 3;

[0272] When the mechanical extension structure 100 is in the sitting position, the backrest drive rod 24 is arranged vertically and tilted forward, such as Figure 5 Mechanical extension structure 100 changes from a sitting position to a TV position during the position, the backrest drive rod 24 rotates clockwise relative to the base 3, such as Figure 5 and Figure 6 During the mechanical extension structure 100 changes from the TV posture position to the lying position, the backrest bracket 23 rotates clockwise relative to the backrest drive rod 24, and the backrest bracket 23 pushes the base 1 forward and upward, such as Figure 6 and Figure 7 shown.

[0273] One end of the driving device 6 is rotatably connected to the base 3 . When the mechanical extension structure 100 is in a sitting position and the backrest driving rod 24 is vertically arranged and tilted forward, the backrest driving rod 24 rotates clockwise to control the movement direction of the driving device 6 .

[0274] When the mechanical extension structure 100 changes from a sitting position to a TV position, the backrest drive rod 24 rotates clockwise relative to the base 3. This structure ensures that the backrest structure 200 does not fall backwards during the change from a sitting position to a TV position, thereby achieving zero wall-retention of the seat unit.

[0275] In this embodiment, the mechanical extension structure 100 also includes a tension spring (not marked), a pull hook is provided at the end of the tension spring, a mounting rod 241 is provided on the backrest drive rod 24, and an annular groove 2411 is provided on the mounting rod 241 for cooperating with the pull hook. When the pull hook is inserted into the annular groove 2411, the tension spring is hung on the mounting rod 241 through the pull hook.

[0276] The annular groove 2411 is used to define the hooking position of the tension spring on the mounting rod 241 , and prevents the hook on the tension spring from sliding relative to the mounting rod 241 , thereby preventing the user's fingers or other parts of the body from extending into the gap between the hook and the mounting rod 241 .

[0277] In other embodiments, the mechanical extension structure further comprises a tension spring, a hook is provided at the end of the tension spring, a mounting rod is provided on the base, and the tension spring is hung on the mounting rod through the hook. Compared with the backrest driving rod, the base has the advantage of being fixed in position, so hanging the tension spring on the mounting rod of the base reduces the variable factors that affect the operation of the tension spring and improves the reliability of the operation of the tension spring.

[0278] Preferably, a flexible muffler (not marked) is provided on the outer wall of the draw hook, and the hardness of the flexible muffler is less than the hardness of the draw hook. When the tension spring is hung on the mounting rod 241 through the draw hook, the flexible muffler is clamped between the draw hook and the groove wall of the annular groove 2411, so that the flexible muffler can reduce the noise generated during the matching process between the draw hook and the annular groove 2411. When the hardness of the flexible muffler is less than the hardness of the pull ring and the flexible muffler is clamped between the draw hook and the groove wall of the annular groove 2411, the flexible muffler further eliminates the gap between the draw hook and the groove wall of the annular groove 2411 through its own deformation; that is, the flexible muffler is used to further reduce the probability of the draw hook sliding relative to the mounting rod 241.

[0279] Preferably, four flexible support rods (not marked) are provided on the base 3 made of metal, and the height of at least two of the flexible support rods is ≥ 9 cm.

[0280] The height dimension of existing sweeping robots is usually 8cm-15mm. Therefore, when the height of at least two support rods is ≥9cm, the sweeping robot can enter the bottom of the seat unit without obstacles and clean the bottom space of the seat unit to avoid dust accumulation at the bottom of the seat unit.

[0281] More preferably, when the base 3 is provided with four flexible support rods, the base 3 is an annular metal frame, for example, a quadrilateral metal frame, an elliptical metal frame, a hexagonal metal frame, etc.

[0282] Preferably, the height of the two support rods in front of the base 3 is ≥ 9 cm, so that the sweeping robot can enter the bottom of the seat unit from the front of the seat unit. More preferably, the height of the four support rods of the base 3 is ≥ 9 cm, so that the sweeping robot can enter the bottom of the seat unit from all directions of the seat unit.

[0283] like Fig.12 As shown, a third reinforcing rib 13 is provided on the base 1 , and the third reinforcing rib 13 is located between a rotation connection between one end of the first support rod 48 and the base 1 and a rotation connection between the second support rod 49 and the base 1 .

[0284] The first support rod 48 and the second support rod 49 need to provide tension for the base 1 for a long time, therefore, adding the third reinforcing rib 13 between the two can effectively increase the service life of the base 1.

[0285] Preferably, a fourth reinforcing rib (not marked) is provided on the first swing arm 45 ; and / or a fifth reinforcing rib (not marked) is provided on the third swing arm 47 .

[0286] When the mechanical extension structure 100 is in the sitting position, the sitting support component 311 abuts against the first swing rod 45; therefore, providing the fourth reinforcing rib on the first swing rod 45 can increase the deformation resistance of the first swing rod 45 to improve the service life of the seat unit.

[0287] When the mechanical extension structure 100 is in the sitting position, the sitting support component 311 abuts against the third swing rod 47; therefore, providing the fifth reinforcing rib on the third swing rod 47 can increase the deformation resistance of the third swing rod 47 to improve the service life of the seat unit.

[0288] In this embodiment, when one end of the front back bracket 22 is rotationally connected to the back plate 21, a first sound-absorbing gasket (unmarked) is clamped between one end of the front back bracket 22 and the back plate 21; and / or, when the other end of the front back bracket 22 is rotationally connected to the base 1, a second sound-absorbing gasket (unmarked) is clamped between the other end of the front back bracket 22 and the base 1.

[0289] In this embodiment, when one end of the backrest bracket 23 is rotationally connected to the backrest board 21, a third sound-absorbing gasket (unmarked) is clamped between one end of the backrest bracket 23 and the backrest board 21; and / or, when the backrest bracket 23 is rotationally connected to the base 1, a fourth sound-absorbing gasket (unmarked) is clamped between the backrest bracket 23 and the base 1.

[0290] The first, second, third and fourth noise-absorbing gaskets have the same functions. Taking the first noise-absorbing gasket as an example, when the first noise-absorbing gasket is clamped between one end of the backrest front bracket 22 and the backrest board 21, the first noise-absorbing gasket is used to increase the contact area between the backrest front bracket 22 and the backrest board 21, reduce the noise during the rotation of the backrest front bracket 22 relative to the backrest board 21, and reduce the gap between the backrest front bracket 22 and the backrest board 21.

[0291] In this embodiment, a plurality of backrest hooks (not marked) are provided on the backrest frame 2001, and the ends of the backrest elastic member 2002 are hung on the backrest hooks. When the ends of the backrest elastic member 2002 are hung on the backrest hooks, a flexible backrest member (not marked) is sandwiched between the ends of the backrest elastic member 2002 and the backrest hooks.

[0292] And / or, the seat cushion frame 3001 is provided with a plurality of seat frame hooks (unmarked), and the end of the seat cushion elastic member 3002 is hung on the seat frame hook. When the end of the seat cushion elastic member 3002 is hung on the seat frame hook, a flexible seat frame member (unmarked) is clamped between the end of the seat cushion elastic member 3002 and the seat frame hook.

[0293] The flexible backrest member is used to reduce the probability of the end of the backrest elastic member 2002 sliding relative to the backrest hook, that is, the flexible backrest member prevents the user's fingers or other parts of the body from extending between the end of the backrest elastic member 2002 and the backrest hook, so as to achieve the purpose of preventing the seat unit from being pinched. Similarly, the flexible seat frame member is used to reduce the probability of the end of the seat cushion elastic member 3002 sliding relative to the seat frame hook, that is, the flexible seat frame member prevents the user's fingers or other parts of the body from extending between the end of the seat cushion elastic member 3002 and the seat frame hook, so as to achieve the purpose of preventing the seat unit from being pinched.

[0294] In this embodiment, the backrest hook and the backrest frame 2001 are integrally formed; the backrest hook and the backrest frame 2001 are integrally formed, and this structure can increase the connection strength between the backrest hook and the backrest frame 2001. In other embodiments, a slide groove is provided on the backrest frame, at least two hooks are connected as a whole to form a slider, and the slider can be slidably inserted into the slide groove; at least two hooks are connected as a whole to form a slider, and the slider can facilitate the replacement of sliders with different numbers of hooks on the backrest frame, that is, different seat units use different numbers of hooks to meet the needs of the backrest structure supporting users of different weights.

[0295] In this embodiment, the backrest decoration cover 2004 is hung on the backrest frame 2001 , and the seat cushion decoration cover 3004 is hung on the seat cushion frame 3001 .

[0296] After the seat unit is used for a long time, the distribution of the backrest filler 2003 in the backrest decorative cover 2004 becomes uneven, and the distribution of the seat cushion filler 3003 in the seat cushion decorative cover 3004 also becomes uneven. Therefore, when the backrest decorative cover 2004 is hung on the backrest frame 2001, the backrest decorative cover 2004 can be removed from the backrest frame 2001 and replaced; when the seat cushion decorative cover 3004 is hung on the seat cushion frame 3001, the seat cushion decorative cover 3004 can be removed from the seat cushion frame 3001 and replaced.

[0297] Preferably, the backrest plate 21 made of metal is snap-connected to the mounting piece made of metal, the backrest frame 2001 made of plastic is fixedly connected to the mounting piece by fasteners (unmarked), and the width of the backrest hook made of plastic is three times or more of the width of the end of the backrest elastic piece 2002.

[0298] The existing backrest frame is made of wood, while in the present invention, the backrest frame 2001 is made of plastic. Under the same volume and shape, the weight of the backrest frame 2001 made of plastic is less than that of the backrest frame made of wood; the backrest hook is made of plastic, and when the end of the backrest elastic member 2002 is hung on one of the backrest hooks, the backrest hook made of plastic can be deformed under the extrusion of the backrest elastic member 2002; and "the width dimension of the backrest hook is three times or more of the width dimension of the end of the backrest elastic member 2002" is used to improve the self-strength of the backrest hook to prevent the backrest hook from being broken by the backrest elastic member 2002 after the seat unit is used for a long time; considering the service life of the backrest hook, the service life of the backrest elastic member 2002, the volume of the backrest hook, and the volume of the backrest elastic member 2002, the width dimension of the backrest hook should be ≥3 times the width dimension of the end of the backrest elastic member 2002, so as to reduce the probability of the backrest hook being broken and the probability of the backrest elastic member 2002 being broken.

[0299] In this embodiment, a decorative cover hook is provided on the backrest frame 2001, and the decorative cover hook is used to hang the backrest decorative cover 2004. In the prior art, a threaded hole needs to be opened on the wall of a backrest frame made of wood by an electric tool, and a fastener cooperates with the threaded hole to clamp the decorative cover hook. In this embodiment, since the backrest frame 2001 is made of plastic, the threaded hole can be integrally formed by the backrest frame. Even if the decorative cover hook is installed on the backrest frame 2001 made of plastic by other means, the difficulty of installing the decorative cover hook on the plastic backrest frame 2001 is much lower than that of installing the decorative cover hook on the wooden backrest frame 2001. Therefore, the backrest frame 2001 made of plastic will be the first choice for adapting the backrest frame to different seat units for a long time to come, especially the backrest frame 2001 used to hang the backrest decorative cover 2004.

[0300] The backrest frame 2001 and the backrest hook can be made of ABS plastic, which is a terpolymer of three monomers: acrylonitrile (A), butadiene (B), and styrene (S). In addition, the backrest frame 2001 and the backrest hook can also be made of PVC, which is polyvinyl chloride (Polyvinyl chloride).

[0301] Preferably, the seat cushion frame 3001 is provided with a first mounting surface and a second mounting surface, and a mounting plate is provided on the base 1, and the mounting plate is located below the upper end surface of the base 1. When the seat cushion structure 300 is installed on the base 1, the seat cushion frame 3001 is stacked above the mounting plate through the first mounting surface, and the seat cushion frame 3001 is stacked above the upper end surface of the base 1 through the second mounting surface.

[0302] The first mounting surface and the second mounting surface are used to increase the connection strength between the seat cushion structure 300 and the base 1 , and the mounting plate is used to increase the contact area between the base 1 and the seat cushion frame 3001 .

[0303] In this embodiment, the base 1 is fixedly connected to the seat cushion structure 300, and the base 3 is fixedly connected to the armrest structure; wherein, the control switch 7 is arranged on the side of the seat cushion structure 300, and the control switch 7 corresponds to the armrest structure; or, the control switch 7 is arranged on the side of the armrest structure, and the control switch 7 is arranged at an angle.

[0304] When the control switch 7 is disposed on the side of the seat cushion structure 300 and the control switch 7 corresponds to the armrest structure, the probability of the control switch 7 being hit by external force is reduced, thereby increasing the service life of the control switch 7.

[0305] In addition, when the control switch 7 is arranged on the side of the seat cushion structure 300 and the control switch 7 corresponds to the armrest structure, the control switch 7 becomes a hidden design. The hidden control switch 7 can avoid damaging the appearance design of the seat unit. At the same time, the hidden control switch 7 can also reduce the probability of the first switch key 71 and the second switch key 73 being accidentally touched.

[0306] When the control switch 7 is disposed on the side of the armrest structure and the control switch 7 is tilted, the user can press the first switch key 71 and the second switch key 73 by naturally bending his fingers, so as to improve the comfort of pressing the buttons.

[0307] A power socket and a wiring harness channel are provided on the handrail frame, the switch seat is arranged in the wiring harness channel, the switch key is connected with a switch power cord, the switch power cord is electrically connected to the power socket, and when the switch key is electrically connected to the power socket through the switch power cord, the switch power cord is located in the wiring harness channel.

[0308] The armrest frame is provided with a cable channel to prevent the switch power cable from moving in the seat unit. When the mechanical extension structure changes from the sitting position to the lying position (or, when the mechanical extension structure changes from the lying position to the sitting position), the cable channel prevents the switch power cable from moving into the movement path of the mechanical extension structure.

[0309] The sofa comprises at least two seat units described in this embodiment. A frame is provided on the mechanical extension structure 100. The frames on adjacent seat units are fixedly connected in a snap-fit ​​manner.

[0310] When the sofa includes two seat units, the frame is arranged on the armrest structure, and the armrest structures on adjacent seat units are fixedly connected by a snap-fit ​​manner; when the sofa includes three seat units, the frame of the leftmost seat unit is arranged on the armrest structure, the frame of the rightmost seat unit is arranged on the armrest structure, and the frame of the middle seat unit is not arranged on the armrest structure.

[0311] When the frames on adjacent seat units are fixedly connected in a snap-fit ​​manner, the sofa can be disassembled into seat units to reduce the difficulty of carrying the sofa; for example, a three-seat sofa can be carried by one porter, a three-seat sofa can enter an elevator, and a three-seat sofa can pass through a door.

[0312] When the sofa includes two seat units and is an armless structure, four flexible support rods are arranged under the base, that is, the support function of the armrest structure for the seat units is replaced by the flexible support rods.

[0313] Preferably, at least one frame is provided with a clamping block, at least one frame is provided with a clamping plate, the clamping plate is provided with a clamping groove with an upward opening, and the clamping block is inserted into the clamping groove to clamp the frames on adjacent seat units.

[0314] The sofa includes at least two seat units described in this embodiment, and an armrest structure is provided on the mechanical extension structure 100. The armrest structure includes an armrest frame, an armrest filler and an armrest decorative cover. The armrest filler is arranged on the armrest frame through the armrest decorative cover. When the armrest filler is arranged on the armrest frame through the armrest decorative cover, the upper width of the armrest structure is greater than the lower width of the armrest structure.

[0315] When the upper width of the armrest structure is greater than the lower width of the armrest structure, the contact area between the upper portion of the armrest structure and the user's arm can be increased to increase the comfort of the user when sitting on the seat unit.

[0316] Preferably, the armrest structure also includes a charging seat and a power cord, the charging seat is provided with a charging interface, the charging seat is fixedly connected to the armrest frame, the armrest frame is provided with a wire harness channel, and the power cord is electrically connected to the charging interface via the wire harness channel.

[0317] In this embodiment, a control switch corresponding to the armrest structure is provided on the seat cushion decorative cover 3004, and the mechanical extension device includes a driving device electrically connected to the control switch. This structure hides the control switch to avoid accidental touch of the control switch and improves the aesthetics of the sofa.

[0318] The seat unit includes an armrest structure, a backrest structure 200, a cushion structure 300, a legrest structure and a mechanical extension structure 100, the mechanical extension structure 100 includes the mechanical extension structure described in the present embodiment, the armrest plate 31 is fixedly connected to the armrest structure, the backrest assembly 2 is fixedly connected to the backrest structure 200, the footrest structure is fixedly connected to the leg assembly 5, and the cushion structure 300 is fixedly connected to the base 1; wherein, a ventilation structure and / or a heating structure is provided on the backrest structure 200.

[0319] In this embodiment, the ventilation structure is used to supply air to the user's back, and the heating structure is used to heat the user's back; since the present invention does not improve the ventilation structure and the heating structure, the ventilation structure and the heating structure will not be described in detail.

[0320] Preferably, the seat cushion structure 300 is also provided with a ventilation structure and / or a heating structure.

[0321] In this embodiment, the upper, lower, front and rear positions of the seat unit are Fig. 9 The direction indicated by the arrow is the standard.

[0322] The above is only an explanation of the best embodiment of the present invention, which should not be construed as a limitation on the claims. The present invention is not limited to the above embodiments, and all changes made within the scope of protection of the independent claims of the present invention are within the scope of protection of the present invention.

Claims

1. A mechanical extension structure, comprising a base, a pedestal, a backrest assembly, a leg assembly, a swing mechanism and a driving device, wherein the base and the pedestal are movably connected through the swing mechanism, the leg assembly is movably arranged in front of the base, the backrest assembly is movably arranged at the rear of the base, the driving device is arranged at the base, and the mechanical extension structure has a sitting position and a lying position; It is characterized in that The mechanical extension structure also includes a control switch, which includes two switch keys and a switch base, and the switch base is provided with two common terminals, two normally closed terminals and two normally open terminals, and each switch key connects one of the common terminals with one of the normally closed terminals, or connects one of the common terminals with one of the normally open terminals; Among them, one of the common terminals is electrically connected to the positive pole of the driving device, the other common terminal is electrically connected to the negative pole of the driving device, the two normally closed terminals are both connected to the negative pole of the power supply, and the two normally open terminals are both connected to the positive pole of the power supply. When the mechanical extension structure changes from a sitting position to a lying position, one of the switch keys connects one of the common terminals and one of the normally open terminals, and the other switch key connects the other common terminal and the other normally closed terminal; when the mechanical extension structure changes from a lying position to a sitting position, one of the switch keys connects one of the common terminals and one of the normally closed terminals, and the other switch key connects the other common terminal and the other normally open terminal.

2. The mechanical extension structure according to claim 1, characterized in that: The power supply includes an external power supply, and the two normally open terminals are respectively electrically connected to the positive pole of the external power supply through a voltage converter; And / or, the power supply includes a battery, and the two normally open terminals are electrically connected to the positive poles of the battery respectively.

3. The mechanical extension structure according to claim 2, characterized in that: When the power supply includes an external power supply and a battery, the mechanical extension structure also includes a controller, a protection switch and a sensor. The positive pole of the battery is electrically connected to the controller through the sensor, the battery is connected to the external power supply through the protection switch, and the controller is electrically connected to the protection switch and is used to connect or disconnect the circuit between the battery and the external power supply.

4. The mechanical extension structure according to claim 1, characterized in that: The mechanical extension structure also includes a controller and a wireless signal receiving module. The wireless signal receiving module is electrically connected to the control switch through the controller.

5. The mechanical extension structure according to claim 1, characterized in that: The controller is electrically connected to the massager and is arranged on the switch seat.

6. The mechanical extension structure according to claim 1, characterized in that: The mechanical extension structure also includes at least one charging socket, and at least one charging socket is arranged on the switch seat, and the charging socket includes a Type-C interface.

7. A seat unit, characterized in that: The mechanical extension structure comprises the mechanical extension structure as claimed in any one of claims 1 to 6, wherein the leg assembly comprises a main legrest mounting plate, a front legrest rotating plate, a rear legrest rotating plate, a front legrest connecting plate and a rear legrest connecting plate, one end of the front legrest rotating plate and one end of the rear legrest rotating plate are respectively rotatably connected to the main legrest mounting plate, the other end of the front legrest rotating plate is rotatably connected to one end of the front legrest connecting plate, the other end of the rear legrest rotating plate is rotatably connected to one end of the rear legrest connecting plate, and the other end of the front legrest connecting plate and the other end of the rear legrest connecting plate are respectively rotatably connected to the base; Wherein, one of the rear leg rest rotating plate and the front leg rest connecting plate is provided with a leg support mechanism, and when the mechanical extension structure is in a lying position, the leg support mechanism abuts against the other of the two.

8. The seating unit according to claim 7, wherein: The seat unit also includes a main legrest structure, which includes a main legrest board and a main legrest decorative cover. The main legrest board is fixedly connected to the main legrest mounting plate, and the main legrest decorative cover is detachably arranged on the main legrest board.

9. The seating unit according to claim 8, wherein: The main footrest decorative cover is hung on the main legrest board; or, a first opening is provided on the main footrest decorative cover, the main legrest board is placed into the main footrest decorative cover through the first opening, and the main footrest decorative cover is provided with a first sealing structure at the first opening, and the first sealing structure includes one of a first linear zipper, a first arc zipper and a first buckle structure.

10. The seating unit according to claim 7, wherein: The leg assembly also includes an auxiliary leg rest mounting plate and a rear leg rest extension plate, one end of the main leg rest mounting plate and the rear leg rest extension plate are respectively rotatably connected to the auxiliary leg rest mounting plate, and the other end of the rear leg rest extension plate is rotatably connected to one end of the front leg rest rotation plate; Or, the leg assembly also includes an auxiliary leg rest mounting plate, a front leg rest extension plate, a rear leg rest extension plate and a control rod, one end of the front leg rest extension plate and one end of the rear leg rest extension plate are respectively rotatably connected to the auxiliary leg rest mounting plate, the other end of the front leg rest extension plate and the other end of the rear leg rest extension plate are respectively rotatably connected to the main leg rest mounting plate, one of the front leg rest extension plate and the rear leg rest extension plate is rotatably connected to one end of the control rod, and the other end of the control rod is rotatably connected to one end of the front leg rest rotating plate.

11. The seating unit according to claim 10, wherein: The seat unit also includes an auxiliary legrest structure, which includes an auxiliary legrest plate and an auxiliary legrest decorative cover. The auxiliary legrest plate is fixedly connected to the auxiliary legrest mounting plate, and the auxiliary legrest decorative cover is detachably arranged on the auxiliary legrest plate.

12. The seating unit of claim 11, wherein: The auxiliary footrest decorative cover is hung on the auxiliary legrest board; or, a second opening is provided on the auxiliary footrest decorative cover, the auxiliary legrest board is placed into the auxiliary footrest decorative cover through the second opening, and the auxiliary footrest decorative cover is provided with a second sealing structure at the second opening, and the second sealing structure includes one of a second linear zipper, a second arc zipper and a second buckle structure.

13. A seating unit according to claim 9 or 10, characterised in that When the seat unit includes a main legrest structure, the main legrest plate is made of plastic, and the main legrest plate is fixedly connected to the main legrest mounting plate by screws or rivets; when the seat unit includes an auxiliary legrest structure, the auxiliary legrest plate is made of plastic, and the auxiliary legrest plate is fixedly connected to the auxiliary legrest mounting plate by screws or rivets.

14. The seating unit of claim 7, wherein: The swing mechanism includes a first connecting rod, a second connecting rod, a third connecting rod, a first swing rod, a second swing rod, a third swing rod, a fourth swing rod, a first supporting rod and a second supporting rod, one end of the first supporting rod and one end of the second supporting rod are respectively rotatably connected to the base, the other end of the first supporting rod and the other end of the second supporting rod are respectively rotatably connected to the third connecting rod, the other end of the first swing rod and the other end of the third swing rod are respectively rotatably connected to the base, the other end of the second swing rod and the other end of the fourth swing rod are respectively rotatably connected to the third connecting rod, one end of the second swing rod is rotatably connected to the first swing rod, one end of the fourth swing rod is rotatably connected to the third swing rod, one end of the first connecting rod is rotatably connected to one end of the first swing rod, the other end of the first connecting rod is rotatably connected to the third swing rod, one end of the second connecting rod is rotatably connected to the first connecting rod, and the other end of the second connecting rod is rotatably connected to the fourth swing rod.

15. The seating unit of claim 7, wherein: The swing mechanism includes a first connecting rod, a second connecting rod, a third connecting rod, a first swing rod, a second swing rod, a third swing rod, a fourth swing rod, a first supporting rod and a second supporting rod, one end of the first supporting rod and one end of the second supporting rod are respectively rotatably connected to the base, the other end of the first supporting rod and the other end of the second supporting rod are respectively rotatably connected to the third connecting rod, the other end of the first swing rod and the other end of the third swing rod are respectively rotatably connected to the base, the other end of the second swing rod and the other end of the fourth swing rod are respectively rotatably connected to the third connecting rod, one end of the second swing rod is rotatably connected to the first swing rod, one end of the fourth swing rod is rotatably connected to the third swing rod, the other end of the first connecting rod is rotatably connected to the fourth swing rod, one end of the first connecting rod is rotatably connected to one end of the first swing rod, the other end of the second connecting rod is rotatably connected to the first connecting rod, and one end of the second connecting rod is rotatably connected to the second swing rod.

16. A seating unit according to claim 14 or 15, characterised in that The leg assembly also includes a linkage rod, one of the front legrest connecting plate and the rear legrest connecting plate is rotatably connected to one end of the linkage rod, and one of the first support rod and the first connecting rod is rotatably connected to the other end of the linkage rod.

17. A seating unit according to claim 14 or 15, characterised in that The driving device comprises a driver, a driving rod is arranged on the driver, a transmission rod is arranged on the driving rod, the driver is rotatably connected to the base, and the front leg rest connecting plate and / or the rear leg rest connecting plate are rotatably connected to the transmission rod.

18. The seating unit of claim 7, wherein: The swing mechanism includes a first support rod and a second support rod, one end of the first support rod and one end of the second support rod are respectively rotatably connected to the base, and the other end of the first support rod and the other end of the second support rod are respectively rotatably connected to the base.

19. The seating unit of claim 18, wherein: The driving device includes a driver, a screw rod, a push block and a transmission structure. The driver is fixedly connected to the base. The driver is provided with a driving rod fixedly connected to the screw rod. The push block is threadedly connected to the screw rod. The transmission structure includes a first transmission rod, a second transmission rod, a third transmission rod and a fourth transmission rod. The second transmission rod is rotatably connected to the base, the push block and the second transmission rod are respectively rotatably connected to the first transmission rod, the second transmission rod and the fourth transmission rod are respectively rotatably connected to the third transmission rod, and the front leg rest connecting plate and / or the rear leg rest connecting plate are rotatably connected to the fourth transmission rod.

20. The seating unit of claim 7, wherein: The swing mechanism includes a swing rod and a swing channel. The swing rod is arranged on the base, and the swing channel is arranged on the pedestal. The swing rod can be inserted into the swing channel. When the swing rod is inserted into the swing channel, the driving device drives the pedestal and the swing mechanism to move forward synchronously through the leg assembly so that the swing rod slides along the swing channel.

21. The seating unit of claim 20, wherein: The swing channel includes a horizontal section and / or an inclined section.

22. The seating unit of claim 7, wherein: One of the front leg rest rotating plate and the rear leg rest rotating plate is provided with a lying position limiting groove matched with the leg support mechanism. When the mechanical extension structure is in the lying position, the leg support mechanism is inserted into the lying position limiting groove and abuts against the groove wall of the lying position limiting groove.

23. The seating unit of claim 7, wherein: The width dimension of the rear leg rest rotating plate is greater than the width dimension of the front leg rest rotating plate, and the gap between the front leg rest rotating plate and the rear leg rest rotating plate is ≤5mm.

24. The seating unit of claim 7, wherein: The seat unit also includes a seat cushion structure and an armrest structure, the base is fixedly connected to the seat cushion structure, and the base is fixedly connected to the armrest structure; The control switch is arranged on the side of the seat cushion structure, and the control switch corresponds to the armrest structure; or the control switch is arranged on the side of the armrest structure, and the control switch is arranged tilted.

25. The seating unit of claim 7, wherein: One of the rear leg rest rotating plate and the front leg rest connecting plate is provided with an anti-pinch sensor, and the anti-pinch sensor is electrically connected to the control switch through a controller.

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