Mechanical stretching structure and seat unit

Abstract

The utility model relates to a mechanical stretching structure and a seat unit, and solves the problems that the seat unit is complex in structure and inconvenient to operate. 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 utility model relates to a mechanical extension structure and a seat unit. Background Art

[0002] In the prior art, a variety of seat units are disclosed. The seat unit includes a backrest structure, a seat cushion structure, a leg rest structure, a mechanical extension structure, and a control switch. The mechanical extension structure has a sitting position and a lying position. During the process that the control switch controls the mechanical extension structure to change from the sitting position to the lying position, the leg rest structure extends forward towards the front of the seat cushion structure, and the backrest structure reclines backward; during the process that the control switch controls the mechanical extension structure to change from the lying position to the sitting position, the leg rest structure retracts downward towards the lower part of the seat cushion structure, and the backrest structure returns to the upright position.

[0003] However, for the existing mechanical extension structure to realize the back-and-forth switching between the sitting position and the lying position, the seat unit has the disadvantages of complex structure and inconvenient operation. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide a mechanical extension structure and a seat unit, which solve the problems of complex structure and inconvenient operation of the seat unit.

[0005] To solve the above technical problems, the utility model 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 pedestal is movably connected to the base through the swing mechanism. The leg assembly is movably arranged on the pedestal, the backrest assembly is movably arranged on the pedestal, and the driving device is arranged on the base;

[0007] The mechanical extension structure has a sitting position and a lying position. During the process that the mechanical extension structure changes from the sitting position to the lying position, the driving device drives the pedestal and the swing mechanism to move forward through the leg assembly, and makes the leg assembly extend in front of the pedestal and the backrest assembly recline relative to the pedestal; during the process that the mechanical extension structure changes from the lying position to the sitting position, the driving device drives the pedestal and the swing mechanism to move backward through the leg assembly, and makes the leg assembly retract below the pedestal and the backrest assembly return to the upright position relative to the pedestal;

[0008] The mechanical extension structure further includes a control switch. The control switch includes two key switches and a switch base. The switch base is provided with two common terminals, two normally closed terminals, and two normally open terminals. Each key switch is connected to one of the common terminals and one of the normally closed terminals, or the key switch is connected to one of the common terminals and one of the normally open terminals;

[0009] Wherein, one common terminal is electrically connected to the positive electrode of the driving device, and the other common terminal is electrically connected to the negative electrode of the driving device. Both normally closed terminals are connected to the negative electrode of the power supply, and both normally open terminals are connected to the positive electrode of the power supply. During the process of the mechanical extension structure changing from the sitting position to the lying position, one of the key switches connects one common terminal to one of the normally open terminals, and the other key switch connects the other common terminal to the other normally closed terminal; during the process of the mechanical extension structure changing from the lying position to the sitting position, one of the key switches connects one common terminal to one of the normally closed terminals, and the other key switch connects the other common terminal to the other normally open terminal.

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

[0011] The control switch includes a first key switch and a second key switch. The first key switch and the second key switch can realize the driving device to control 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 terminal is electrically connected to the positive electrode of the driving device through the first electrical connection line, the first common terminal is electrically connected to the negative electrode of the driving device through the second electrical connection line, the first normally closed terminal and the second normally closed terminal are electrically connected through the third electrical connection line, the first normally closed terminal is electrically connected to the negative electrode of the power supply through the fourth electrical connection line, the first normally open terminal and the second normally open terminal are electrically connected through the fifth electrical connection line, and the second normally open terminal is electrically connected to the positive electrode of the power supply through the sixth electrical connection line.

[0012] Preferably, the control switch further includes a reaction spring. The key switch is arranged on the switch base and can abut against the switch base. The reaction spring is clamped between the key switch and the switch base. When the reaction spring releases elastic force to push the key switch to abut against the switch base, the key switch connects one common terminal to one of the normally closed terminals; when the key switch presses the reaction spring and separates from the switch base, the key switch connects one common terminal to one of the normally open terminals.

[0013] When the control switch further includes a reaction spring, the control switch is a physical switch; the reaction spring can automatically cut off the power supply of the driving device through its own elastic force, that is, the mechanical extension structure realizes the automatic power-off of the control switch with the addition of one part. This structure improves the operation convenience of the seat unit on the basis of the simple structure of the mechanical extension structure.

[0014] Preferably, the power supply includes an external power supply, and the two normally open terminals 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 storage battery, and the two normally open terminals are respectively electrically connected to the positive electrode of the storage battery.

[0016] The voltage between the live wire and the neutral wire of domestic civil electricity is usually 220V, while the voltage of the driving device (the input voltage of the driving device is usually about 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 storage battery, the mechanical stretching structure can realize the transformation between the sitting position and the lying position without connecting to an external power supply.

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

[0019] The controller can be an MCU, the controller can also be a CPU, and the controller can also be a microprocessor (MicroProcessor Unit).

[0020] According to the prior art, it can be known that: the charging voltage of a storage battery with a power storage capacity of 50%, the charging voltage of a storage battery with a power storage capacity of 80%, and the charging voltage of a storage battery with a power storage capacity of 95% are different; the charging current of a storage battery with a power storage capacity of 50%, the charging current of a storage battery with a power storage capacity of 80%, and the charging current of a storage battery with a power 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 storage battery through the sensor; since the charging voltage of the storage battery is different at different power storage levels, the controller obtains the real-time charging voltage of the positive electrode of the storage battery through the sensor to realize the controller's monitoring of the power storage capacity of the storage 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 storage battery through the sensor. Since the charging current of the storage battery is different at different power storage levels, the controller obtains the real-time charging current of the positive electrode of the storage battery through the sensor to realize the controller's monitoring of the power storage capacity of the storage battery.

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

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

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

[0026] Taking the triode 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 triode, the touch screen changes the state of the triode through the controller to connect or disconnect the circuit between the driving device and the external power supply.

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

[0028] Preferably, the mechanical extension structure further includes 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 the remote control of the control switch, and this structure effectively improves the operation convenience of the seat unit.

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

[0030] Preferably, the controller is electrically connected to a 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 through the switch seat.

[0031] Preferably, the mechanical extension structure further 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 through a data cable, enabling users to charge their devices while sitting on the seat unit and using their mobile phones or tablets.

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

[0034] Among them, one of the rear leg rest rotating plate and the front leg rest connecting plate is provided with a leg support mechanism. When the mechanical extension structure is in the reclined position, the leg support mechanism abuts against the other one of them.

[0035] When the mechanical extension structure is in the reclined 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 drive device. During the process of removing the drive device by the user, 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 hardly changes, that is, the main foot rest structure will not hit the user during the process of removing the drive device.

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

[0037] The seat unit further includes a backrest structure and an armrest structure. The backrest assembly is movably provided on the backrest structure. The armrest structure includes an armrest frame, and the armrest frame includes two side armrest plates and one rear armrest plate. The base is fixedly connected to the side armrest plates, and the two side armrest plates are fixedly connected by the rear armrest plate. When the mechanical extension structure is in the reclined position, the distance between the rear armrest plate and the backrest structure is ≥ 10 cm.

[0038] The width of the user's arm is usually about 10 cm. Therefore, when the mechanical extension structure is in the reclined position and the distance between the rear armrest plate and the backrest structure is ≥ 10 cm, the user's arm can extend into the armrest frame through the gap between the backrest structure and the rear armrest plate to facilitate the removal and installation of the drive device. This structure further improves the convenience of the maintenance operation of the seat unit.

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

[0040] In the prior art, the main leg rest decorative cover is installed on the main leg rest board in a semi-permanent fixing manner. For example, the main leg rest decorative cover is fixed on the main leg rest board by the nails of a pneumatic gun; or, a nail is knocked by a hammer to fix the main leg rest decorative cover on the main leg rest board. This makes the assembly speed of the main leg rest structure slow and the manufacturing cost high.

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

[0042] The secondary leg rest structure is the same as the main leg rest structure, so it will not be elaborated here.

[0043] Preferably, the main foot rest decorative cover is hung on the main leg rest board; or, the main foot rest decorative cover is provided with a first opening, the main leg rest board is placed into the main foot rest decorative cover through the first opening, and the main foot rest decorative cover is provided with a first sealing structure at the first opening. The first sealing structure includes one of a first straight 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 size of the main leg rest decorative cover 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 arts, so the above structures will not be elaborated here; the first sealing structure using the first straight zipper has the advantages of simple structure and low cost; the first sealing structure using the first arc zipper has the advantage that the main leg rest board is easy to disassemble and assemble; the first buckle structure has the advantage that the sealing structure is not easy to open. The first buckle structure includes a clamping member and a fastening member. The clamping member is arranged on one side of the main leg rest decorative cover at the first opening, and the fastening member is arranged on the other side of the main leg rest decorative cover at the first opening. Of course, using the first sealing structure can facilitate the replacement of the foot rest decorative cover and also facilitate the cleaning of the foot rest decorative cover.

[0046] The width dimension of the first arc zipper is greater than the width dimension of the main leg rest board, which further increases the deformation size that the first opening can occur. This structure further reduces the probability of the first opening being damaged during the installation of the main leg rest board.

[0047] Preferably, the leg assembly further includes a secondary 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 secondary 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 rotating plate;

[0048] Alternatively, the leg assembly further includes a secondary 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 secondary 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, and 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 rod is used to control the movement posture of the secondary leg rest mounting plate.

[0050] Preferably, the seat unit further includes a secondary leg rest structure. The secondary leg rest structure includes a secondary leg rest plate and a secondary leg rest decorative cover. The secondary leg rest plate is fixedly connected to the secondary leg rest mounting plate, and the secondary leg rest decorative cover is detachably arranged on the secondary leg rest plate. This structure improves the operational convenience of disassembling, assembling, and replacing the secondary leg rest plate.

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

[0052] The width dimension of the second arc zipper is greater than the width dimension of the secondary leg rest plate, which further increases the dimension of the deformation that the second opening can undergo. This structure further reduces the probability of damage to the second opening during the installation of the secondary leg rest plate.

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

[0054] The main leg rest plate (secondary leg rest plate) 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 handling the seat unit during transportation.

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

[0056] The main leg rest plate made of plastic is easy to form. That is, the main leg rest plate can be provided with hooks or hanging rings for hanging the main foot rest decorative cover by means of blow molding or extrusion molding. In addition, the main leg rest plate made of plastic has another advantage that the hooks or hanging rings can be formed by concave-convex of the main leg rest plate. This structure can effectively increase the regularity of the outer contour of the main leg rest plate and avoid damaging the user experience of the seat unit by the main foot rest plate.

[0057] Preferably, a main leg rest filler is provided inside the main leg rest decorative cover. When the main leg rest decorative cover is detachably arranged on the main leg rest plate, the main leg rest filler is clamped between the main leg rest decorative cover and the main leg rest plate. The main leg rest filler is used to increase the comfort during the user's leg rest.

[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 one end of 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. 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 one end of 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. 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. 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 the sitting position to the lying position (or during the process of the mechanical extension structure changing from the lying position to the sitting position), the linkage rod is used to increase the motion synchronization between the swing mechanism and the base, avoiding the incoordination of the actions of the leg assembly and the base. For example, interference between the leg assembly and the base, an increase in the distance between the leg assembly and the base, a 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 support connecting plate and / or the rear leg support 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 includes a driver, a lead screw, a push block and a transmission structure. The driver is fixedly connected to the base, a driving rod fixedly connected to the lead screw is provided on the driver, and the push block is threadedly connected to the lead screw;

[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 support connecting plate and / or the rear leg support 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 provided on the base, the swing channel is provided on the base, 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 rotating plate and the front leg connecting plate is provided with a lying position limiting groove for cooperating 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.

[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 rotating plate from moving relative to the front leg 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 dimension of the rear leg rest rotating plate is greater than that 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 ≤ 5 mm.

[0071] Since the thickness of a user's finger is usually above 5 mm, therefore, making "the gap between the front leg rest rotating plate and the rear leg rest rotating plate is ≤ 5 mm" can further reduce the probability of a user's finger being accidentally pinched. This structure reduces or avoids a user's finger from reaching between the front leg rest rotating plate and the rear leg rest rotating plate by increasing the width dimension 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 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;

[0073] Wherein, 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 inclined.

[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 an external force becomes smaller, 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 on-off key and the second on-off key being accidentally touched.

[0076] When the control switch is arranged on the side of the armrest structure and the control switch is inclined, a user's finger can naturally bend to press the first on-off key and the second on-off key, so as to improve the comfort of pressing the keys.

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

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

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

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

[0081] Figure 4 It is a perspective view of the mechanical extension structure (the first structure) in the lying position in the present utility model;

[0082] Figure 5 It is a schematic structural view of the control switch and the external power supply in the present utility model;

[0083] Figure 6 It is a schematic structural view of the control switch and the storage battery in the present utility model;

[0084] Figure 7 It is a schematic circuit connection view of the seat unit in the present utility model;

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

[0086] Figure 9 It is a front view of the seat unit in the present utility model (the mechanical extension structure is in the sitting position);

[0087] Figure 10 It is a perspective view of the mechanical extension structure (the first structure) in the sitting position in the present utility model;

[0088] Figure 11 It is a perspective view of the mechanical extension structure (the first structure) in the TV position in the present utility model;

[0089] Figure 12 It is a perspective view of the mechanical extension structure (the first structure) in the sitting position in the present utility model;

[0090] Figure 13 It is a perspective view of a part of the swing mechanism (the first structure) in the present utility model;

[0091] Figure 14 It is a perspective view of the swing mechanism (the first structure) in the present utility model;

[0092] Figure 15 It is a perspective view of the swing mechanism (the second structure) in the present utility model;

[0093] Figure 16 It is a perspective view of the backrest assembly (the third structure) in the present utility model. Detailed implementation manners

[0094] The following is a further detailed description of the present utility model through specific implementation examples in combination with the drawings:

[0095] Such as Figure 1 And Figure 4As shown, the present utility model discloses a mechanical extension structure 100, which includes a base 3, a pedestal 1, a backrest assembly 2, a leg assembly 5, a swing mechanism 4, and a driving device 6. The pedestal 1 is movably connected to the base 3 through the swing mechanism 4. The leg assembly 5 is movably disposed on the pedestal 1, the backrest assembly 2 is movably disposed on the pedestal 1, and the driving device 6 is disposed on the base 3;

[0096] As Figure 1 and Figure 3 shown, the mechanical extension structure 100 has a sitting position and a lying position. During the process of the mechanical extension structure 100 changing from the sitting position to the lying position, the driving device 6 drives the pedestal 1 and the swing mechanism 4 to move forward through the leg assembly 5, and makes the leg assembly 5 extend in front of the pedestal 1 and the backrest assembly 2 recline relative to the pedestal 1; during the process of the mechanical extension structure 100 changing from the lying position to the sitting position, the driving device 6 drives the pedestal 1 and the swing mechanism 4 to move backward through the leg assembly 5, and makes the leg assembly 5 retract under the pedestal 1 and the backrest assembly 2 return to the upright position relative to the pedestal 1;

[0097] As Figure 5 and Figure 6 shown, the mechanical extension structure 100 further includes a control switch 7. The control switch 7 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 to the first normally closed terminal 753, or the first switch key 71 connects the first common terminal 751 to the first normally open terminal 752; the second switch key 73 connects the second common terminal 754 to the second normally closed terminal 756, and the second switch key 73 connects the second common terminal 754 to 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. During the process of the mechanical extension structure 100 changing from the sitting position to the lying position, the second switch key 73 connects the second common terminal 754 to the second normally open terminal 755, and the first switch key 71 connects the first common terminal 751 to the first normally closed terminal 753; during the process of the mechanical extension structure 100 changing from the lying position to the sitting position, the first switch key 71 connects the first common terminal 751 to the first normally open terminal 752, and the second switch key 73 connects the second common terminal 754 to the second normally closed terminal 756.

[0099] As Figure 5 and Figure 6As shown, the first power switch 71 and the second power switch 73 can drive the driving device 6 to control the mechanical extension structure 100 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 terminal 754 is electrically connected to the positive pole of the driving device 6 through the first electrical connection line, the first common terminal 751 is electrically connected to the negative pole of the driving device 6 through the second electrical connection line, the first normally closed terminal 753 is electrically connected to the second normally closed terminal 756 through the third electrical connection line, the first normally closed terminal 753 is electrically connected to the negative pole of the power supply 86 through the fourth electrical connection line, the first normally open terminal 752 is electrically connected to the second normally open terminal 755 through the fifth electrical connection line, and the second normally open terminal 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 power switch 71 is arranged on the switch base and can abut against the switch base. The first reaction spring 72 is clamped between the first power switch 71 and the switch base. When the first reaction spring 72 releases its elastic force to push the first power switch 71 to abut against the switch base, the first power switch 71 connects the first common terminal 751 and the first normally closed terminal 753; when the first power switch 71 squeezes the first reaction spring 72 and separates from the switch base, the first power switch 71 connects the first common terminal 751 and the first normally open terminal 752. Similarly, the second power switch 73 is arranged on the switch base and can abut against the switch base. The second reaction spring 74 is clamped between the second power switch 73 and the switch base. When the second reaction spring 74 releases its elastic force to push the second power switch 73 to abut against the switch base, the second power switch 73 connects the second common terminal 754 and the second normally closed terminal 756; when the second power switch 73 squeezes the second reaction spring 74 and separates from the switch base, the second power switch 73 connects the second common terminal 754 and the second normally open terminal 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 through their own elastic forces, that is, the first reaction spring 72 and the second reaction spring 74 also increase the safety of the control switch 7 during the working process by using the mechanical structure.

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

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

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

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

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

[0107] The controller 81 can be an MCU, the controller 81 can also be a CPU, and the controller 81 can also be a microprocessor (MicroProcessor Unit).

[0108] According to the prior art, it can be known that: the charging voltage of the storage battery 83 with a power storage capacity of 50%, the charging voltage of the storage battery 83 with a power storage capacity of 80%, and the charging voltage of the storage battery 83 with a power storage capacity of 95% are different; the charging current of the storage battery 83 with a power storage capacity of 50%, the charging current of the storage battery 83 with a power storage capacity of 80%, and the charging current of the storage battery 83 with a power 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 storage battery 83 through the sensor 85; since the charging voltage of the storage battery 83 is different at different power storage levels, therefore, the controller 81 obtains the real-time charging voltage of the positive electrode of the storage battery 83 through the sensor 85 to realize the controller 81 monitoring the power storage capacity of the storage battery 83.

[0110] Similarly, the sensor 85 can also be a current sensor, and the controller 81 obtains the real-time charging current of the positive electrode of the storage battery 83 through the sensor 85. Since the charging current of the storage battery 83 is different at different power storage levels, therefore, the controller 81 obtains the real-time charging current of the positive electrode of the storage battery 83 through the sensor 85 to realize the controller 81 monitoring the power storage capacity of the storage battery 83.

[0111] Since the storage battery 83 and the external power supply 861 are connected through the protection switch 82, after the controller 81 obtains that the stored power of the storage battery 83 reaches the preset maximum stored power, the controller 81 disconnects the circuit between the storage battery 83 and the external power supply 861 through the protection switch 82; after the controller 81 obtains that the stored power of the storage battery 83 reaches the preset minimum stored power, the controller 81 connects the circuit between the storage 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 through one of a triode, a MOS transistor, and a relay, and the controller 81 is electrically connected to one of a triode, a MOS transistor, and a relay.

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

[0114] Taking the triode 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 driving device 6 is electrically connected to the external power supply 861 through the triode, the touch screen changes the state of the triode through the controller 81 so that the triode connects or disconnects the circuit between the driving device 6 and the external power supply 861.

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

[0116] As Figure 7 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 further includes a controller 81 and a wireless signal receiving module 84, the control switch 7 includes one or more of a triode, a MOS transistor, and a relay. After the wireless signal receiving module 84 receives a control signal from a remote control device (such as a mobile phone, a tablet computer, a remote controller), the wireless signal receiving module 84 transmits the control signal to the controller 81, and the controller 81 controls the driving device 6 through the control switch 7 to realize the mechanical extension structure 100 to switch back and forth between the sitting position and the lying position.

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

[0119] A mobile phone and a tablet computer can be connected to the Type-C interface through a data cable so that a user can charge the mobile phone or the tablet computer while sitting on the seat unit.

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

[0121] Wherein, one of the rear leg rotating plate 54 and the front leg connecting plate 55 is provided with a leg support mechanism 541. When the mechanical extension structure 100 is in the reclined position, the leg support mechanism 541 abuts against the other one of them. Figure 4 As can be seen, in this embodiment, the leg forming mechanism 541 is provided on the rear leg rotating plate 54. When the mechanical extension structure 100 is in the reclined position, the leg support mechanism 541 abuts against the front leg connecting plate 55.

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

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

[0124] The seat unit further includes a backrest structure 200 and an armrest structure (not marked). The backrest assembly 2 is movably provided on the backrest structure 200. The armrest structure includes an armrest frame (not marked). The armrest frame is a prior art, that is, the armrest frame includes two side armrest plates and one rear armrest plate. The base 3 is fixedly connected to the side armrest plates. The two side armrest plates are fixedly connected by the rear armrest plate. When the mechanical extension structure 100 is in the reclined position, the distance between the rear armrest plate and the backrest structure 200 is ≥10 cm.

[0125] The width of the user's arm is usually about 10 cm. Therefore, when the mechanical extension structure 100 is in the reclined position and the distance between the rear armrest plate and the backrest structure 200 is ≥10 cm, the user's arm can extend into the armrest frame through the gap between the backrest structure 200 and the rear armrest plate to disassemble and assemble the drive device 6.

[0126] Preferably, the seat unit further includes a main leg rest structure (not marked), which includes a main leg rest plate and a main leg rest decorative cover. The main leg rest plate is fixedly connected to the main leg rest mounting plate 51, and the main leg rest decorative cover is detachably arranged on the main leg rest plate.

[0127] In the prior art, the main leg rest decorative cover is installed on the main leg rest plate in a semi-permanent fixing manner. For example, the main leg rest decorative cover is fixed on the main leg rest plate by the nails of a pneumatic gun; or, a nail is knocked by a hammer to fix the main leg rest decorative cover on the main leg rest plate. This makes the assembly speed of the main leg rest structure slow and the manufacturing cost high.

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

[0129] The secondary leg rest structure is the same as the main leg rest structure, so it will not be elaborated here.

[0130] Preferably, the main foot rest decorative cover is hung on the main leg rest plate; or, the main foot rest decorative cover is provided with a first opening, the main leg rest plate is placed into the main foot rest decorative cover through the first opening, and the main foot rest decorative cover is provided with a first sealing structure at the first opening. The first sealing structure includes one of a first straight zipper, a first arc zipper and a first snap structure.

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

[0132] The first straight zipper, the first arc zipper and the first snap structure are all prior arts, so the above structures will not be elaborated here; the first sealing structure using the first straight zipper has the advantages of simple structure and low cost; the first sealing structure using the first arc zipper has the advantage that the main leg rest plate is easy to disassemble and assemble; the first snap structure has the advantage that the sealing structure is not easy to open. The first snap structure includes a clamping member and a fastening member. The clamping member is arranged on one side of the main leg rest decorative cover at the first opening, and the fastening member is arranged on the other side of the main leg rest decorative cover at the first opening. Of course, using the first sealing structure can facilitate the replacement of the foot rest decorative cover and also facilitate the cleaning of the foot rest decorative cover.

[0133] The width dimension of the first arc zipper is greater than the width dimension of the main leg rest plate, which further increases the deformation size that the first opening can occur, and this structure further reduces the probability of the first opening being damaged during the installation of the main leg rest plate.

[0134] Such as Figure 3 and Figure 10As shown, one structure of the leg assembly 5 further includes a secondary 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 secondary 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] As Figure 8 shown, another structure of the leg assembly 5 further includes a secondary leg rest mounting plate 52, a front leg rest extension plate 57, a rear leg rest extension plate 58 and a control rod 59. One end of the front leg rest extension plate 57 and one end of the rear leg rest extension plate 58 are respectively rotatably connected to the secondary leg rest mounting plate 52, the other end of the front leg rest extension plate 57 and the other end of the rear leg rest extension plate 58 are respectively rotatably connected to the main leg rest mounting plate 51. One of the front leg rest extension plate 57 and the rear leg rest 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 leg rest rotating plate 53. In this embodiment, the rear leg rest 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 secondary leg rest mounting plate 52.

[0137] Preferably, the seat unit further includes a secondary leg rest structure, which includes a secondary leg rest plate and a secondary leg rest decorative cover. The secondary leg rest plate is fixedly connected to the secondary leg rest mounting plate 52, and the secondary leg rest decorative cover is detachably arranged on the secondary leg rest plate.

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

[0139] The width dimension of the second arc zipper is greater than the width dimension of the secondary leg rest plate, which further increases the dimension of the deformation that the second opening can undergo. This structure further reduces the probability of damage to the second opening during the installation of the secondary leg rest plate.

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

[0141] The main leg rest plate (secondary leg rest plate) 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 handling the seat unit during transportation.

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

[0143] The main leg rest board made of plastic is easy to mold. That is, the main leg rest board can be provided with hooks or hanging rings for hanging the main footrest decorative cover by blow molding or extrusion molding. In addition, the main leg rest board made of plastic has another advantage that the hooks or hanging rings can be formed by concave in the main leg rest board. This structure can effectively increase the regularity of the outer contour of the main leg rest board and avoid damaging the user experience of the seat unit by the main footrest board.

[0144] Preferably, a main leg rest filler is provided inside the main leg rest decorative cover. When the main leg rest decorative cover is detachably arranged on the main leg rest board, the main leg rest filler is clamped between the main leg rest decorative cover and the main leg rest board. The main leg rest filler is used to increase the comfort during the user's leg resting process.

[0145] Such as Figure 13 and Figure 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. 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 3. 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 connecting rod 43. One end of the second swing rod 44 is rotatably connected to one end of the first swing rod 45. One end of the fourth swing rod 46 is rotatably connected to one end of the third swing rod 47. 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 first connecting rod 41 is rotatably connected to the third swing rod 47. One end of the second connecting rod 42 is rotatably connected to one end of the first connecting rod 41. The other end of the second connecting rod 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 one end of the first swing rod 45 and the other end of the first swing rod 45 is in front of the other end of the second swing rod 44, therefore, the second swing rod 44 and the first swing rod 45 form a support structure in the shape of a "V". Similarly, since one end of the fourth swing rod 46 is rotatably connected to one end of the third swing rod 47 and the other end of the third swing rod 47 is in front of the other end of the fourth swing rod 46, therefore, the fourth swing rod 46 and the third swing rod 47 also form a support structure in the shape of a "V". The "V"-shaped support structure has a relatively stable supporting effect.

[0147] In addition, when the mechanical extension structure 100 is in the lying position, the other end of the first swing rod 45 is behind the other end of the second swing rod 44, and the other end of the third swing rod 47 is behind the other end of the fourth swing rod 46; during the process of the mechanical extension structure 100 changing from the sitting position to the lying position, the other end of the second swing rod 44 moves from behind the other end of the first swing rod 45 to in front of the other end of the first swing rod 45, and the other end of the fourth swing rod 46 moves from behind the other end of the third swing rod 47 to in front of the other end of the third swing rod 47; during the process of the mechanical extension structure 100 changing from the lying position to the sitting position, the other end of the second swing rod 44 moves from in front of the other end of the first swing rod 45 to behind the other end of the first swing rod 45, and the other end of the fourth swing rod 46 moves from in front of the other end of the third swing rod 47 to behind the other end of the third swing rod 47. In this structure, the first swing rod 45 and the second swing rod 44 cooperate with each other, and the third swing rod 47 and the fourth swing rod 46 cooperate with each other to control the forward movement distance of the third connecting rod 43, and 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 connecting rod 43, one end of the first connecting rod 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 connecting rod 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, therefore, the third connecting rod 43, the second swing rod 44, the fourth swing rod 46 and the first connecting rod 41 form a movement structure similar to a quadrilateral; as is well known, the quadrilateral structure has the disadvantage of uncertain movement postures. Thus, the swing mechanism 4 controls the movement postures 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 rotatably connected to the first connecting rod 41, and the other end of the second connecting rod 42 is rotatably connected to the fourth swing rod 46), and further controls the movement postures of the first swing rod 45 and the second swing rod 44; among them, the other end of the second connecting rod 42 is mainly used to control the movement posture of the fourth swing rod 46, and the other end of the first connecting rod 41 is mainly used to control the movement posture of the third swing rod 47.

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

[0150] Such as Figure 15As shown in the figure, 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, 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 third connecting rod 43. 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 3. 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 connecting rod 43. One end of the second swing rod 44 is rotatably connected to the first swing rod 45, and 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, and 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 connecting rod 43, 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, and one end of the second swing rod 44 is rotatably connected to the first swing rod 45, therefore, the third connecting rod 43, the second swing rod 44, the fourth swing rod 46 and the first connecting rod 41 form a motion structure similar to a quadrilateral. As is well known, the quadrilateral structure has the disadvantage of uncertain motion postures. Thus, the swing mechanism 4 controls the motion postures of the first swing rod 45 and the second swing rod 44 through the second connecting rod 42 (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), and further controls the motion postures of the third swing rod 47 and the fourth swing rod 46. Among them, one end of the second connecting rod 42 mainly controls the motion posture of the second swing rod 44, and one end of the first connecting rod 41 mainly controls the motion posture of the first swing rod 45. The second connecting rod 42 is used to increase the anti-deformation ability 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 the rotational connection between one end of the second connecting rod 42 and the position above the middle of the second swing rod 44. During the process of the mechanical extension structure 100 changing 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 first swing rod 45 to be lengthened. That is to say, the rotational connection between one end of the second connecting rod 42 and the position above the middle 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 leg rest connecting plate 55 and the rear leg rest 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. As Figure 11 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 the sitting position to the lying position (or during the process of the mechanical extension structure 100 changing from the lying position to the sitting position), the linkage rod 65 is used to increase the motion synchronization of the swing mechanism 4 and the base 1, and avoid the incoordination of the actions of the leg assembly 5 and the base 1. For example, the leg assembly 5 interferes with the base 1, the distance between the leg assembly 5 and the base 1 becomes larger, the distance between the leg assembly 5 and the base 1 becomes smaller, etc.

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

[0154] As Figure 8 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 drive device includes a driver, a lead screw, a push block and a transmission structure. The driver is fixedly connected to the base 3, a drive rod fixedly connected to the lead screw is provided on the driver, and the push block is threadedly connected to the lead screw; 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 leg rest connecting plate 55 and / or the rear leg rest connecting plate 56 is rotatably connected to the fourth transmission rod 66. In this embodiment, the front leg rest 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] There are many defects in the existing seat unit. One of the defects of the seat unit 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 structure of the swing mechanism 4 is complex and the manufacturing cost is high. However, when the mechanical extension structure switches back and forth between the sitting position and the lying position, the seat unit is not likely to shake; 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, when the mechanical extension structure switches back and forth between the sitting position and the lying position, the seat unit is not only not likely to shake, but also the manufacturing cost of the seat unit is 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, where the inclined section can be a straight section or an arc section.

[0159] As Figure 8 shown, one of the rear leg rotating plate 54 and the front leg connecting plate 55 is provided with a lying position limiting groove 541 for cooperating 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 arranged on the front leg connecting plate 55, and the lying position limiting groove 541 is arranged on the rear leg rotating plate 54.

[0160] When 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, the lying position limiting groove 541 prevents the rear leg rotating plate 54 from moving relative to the front leg connecting plate 55 through the leg support mechanism 551, so as to improve the stability of the user's legs placed on the main footrest structure.

[0161] Preferably, the width dimension of the rear leg rest rotating plate 54 is greater than that 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 more than 5 mm, making "the gap between the front leg rest rotating plate 53 and the rear leg rest rotating plate 54 is ≤ 5 mm" can further reduce the probability of the user's finger being accidentally pinched. This structure reduces or avoids the user's finger from reaching between the front leg rest rotating plate 53 and the rear leg rest rotating plate 54 by increasing the width dimension 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. The seat unit includes a leg rest structure, an armrest structure, a seat cushion structure, and a mechanical extension structure. A user's buttocks can sit above the seat cushion structure. Among them, the mechanical extension structure has a sitting position and a lying position. After the mechanical extension structure changes from the sitting position to the lying position, the user's legs can be placed above the leg rest structure. The mechanical extension structure includes a swing mechanism, a leg component, a base, and a pedestal. The pedestal is fixedly connected to the armrest structure. The seat cushion structure is installed above the base. The leg rest structure is installed on the leg component. The leg component is rotatably connected to the base. The base and the pedestal are connected by a swing mechanism. The base supports the pedestal through the swing mechanism to enable the pedestal to provide a supporting force for the user's buttocks through the seat cushion structure. However, after long-term use of the existing seat unit, the seat cushion structure will shake to a certain extent relative to the armrest structure.

[0164] In Figure 9 and Figure 12 of the present utility model, a mechanical extension structure 100 is disclosed, which includes a base 3, two pedestals 1 for installing a seat cushion structure 300, two groups of leg components 5 for installing a leg rest structure, two groups of backrest components 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 components 5 is rotatably connected to a pedestal 1. Each pedestal 1 is movably connected to the base 3 through a group of swing mechanisms 4. Each pedestal 1 is also connected to the base 3 through a group of backrest components 2;

[0165] During the process of the mechanical extension structure 100 changing 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 extends the leg assembly 5 in front of the base 1; during the process of the mechanical extension structure 100 changing 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 retracts the leg assembly 5 under the base 1. The mechanical extension structure 100 further includes at least one sitting posture support member 311, and the sitting posture support member 311 is fixedly connected to the base 3. When the mechanical extension structure 100 is in the sitting position, the sitting posture support member 311 supports the swing mechanism 4; when the mechanical extension structure 100 is in the lying position, the sitting posture support member 311 is separated from the swing mechanism 4.

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

[0167] Of course, some existing seat units have no armrest structure. The seat unit without an armrest structure is provided with four flexible support rods under its base, that is, the flexible support rods replace the support function of the armrest structure for the seat unit.

[0168] When the sitting posture support member 311 is located below the swing mechanism 4 and the sitting posture support member 311 abuts against the swing mechanism 4, the upper part of the sitting posture support member 311 supports the swing mechanism 4; since the base 1 and the base 3 are connected by the swing mechanism 4, when the mechanical extension structure 100 is in the sitting position and the sitting posture support member 311 is used to support the swing mechanism 4, the sitting posture support member 311 will support the base 1 through the swing mechanism 4. When a user sits above 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 member 311 will support the base 1 through the swing mechanism 4 to enable the base 1 to provide a 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 above the seat cushion structure 300.

[0169] During the process of the mechanical extension structure 100 changing 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. Since the armrest structure prevents the sitting posture support member 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 posture support member 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 component 5" can be that the driving device 6 directly drives the swing mechanism 4 to move forward through the leg component 5, or "the driving device 6 drives the base 1 and the swing mechanism 4 to move forward through the leg component 5" can also be that the driving device 6 indirectly drives the swing mechanism 4 to move forward through the leg component 5. For example, the driving device 6 drives the base 1 to move forward through the leg component 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 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 component 5. Since the armrest structure prevents the sitting posture support member 311 from moving with the mechanical extension structure 100 through the base 3, therefore, after the driving device 6 drives the swing mechanism 4 to move backward through the leg component 5, the sitting posture support member 311 can abut against the swing mechanism 4.

[0172] As Figure 13 shown, the sitting posture support member 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 deforms. This structure is used to reduce the probability that the sitting posture support rod and the swing mechanism 4 bend 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 member 311 is fixedly connected to the armrest plates 31. Since the base 3 includes two armrest plates 31 and the sitting posture support member 311 is fixedly connected to the armrest plates 31, therefore, when the sitting posture support member 311 includes a sitting posture support rod and the sitting posture support rod abuts against the swing mechanism 4, the single sitting posture support rod improves its position accuracy on the armrest plates 31 to enable the sitting posture support rods on both sides to respectively abut against their respective swing mechanisms 4, thereby extending the service life of all sitting posture support rods.

[0174] Preferably, the hardness of the sitting posture support rod is lower than that 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 deforms.

[0175] Of course, in other embodiments, the sitting posture support member 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 posture position, the sitting posture support ring is located below the swing mechanism, and the sitting posture support ring abuts against the swing mechanism; when the mechanical extension structure is in the lying posture position, the sitting posture support ring is separated from the swing mechanism. When the sitting posture support ring abuts against 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 deforms. This structure is used to reduce the probability that 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 bend under the action of the squeezing force after the sitting posture support ring abuts against the swing mechanism. In addition, by removing the sitting posture support rod from the base, at least one component on the sitting posture support member can be replaced.

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

[0177] When the lying posture support member 12 is located above the swing mechanism 4 and the lying posture support member 12 abuts against the swing mechanism 4, the swing mechanism 4 supports the lower part of the lying posture support member 12; since the lying posture support member 12 is fixedly connected to the base 1, when the mechanical extension structure 100 is in the lying posture position and the swing mechanism 4 is used to support the lying posture support member 12, the swing mechanism 4 supports the base 1 through the lying posture support member 12. When the user's buttocks sit above the seat cushion structure 300, the user's buttocks apply gravity to the base 1 through the seat cushion structure 300; the swing mechanism 4 supports the base 1 through the lying posture support member 12 to enable the base 1 to provide a 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 above the seat cushion structure 300.

[0178] During the process of the mechanical extension structure 100 changing from the sitting posture position to the lying posture position, the driving device 6 drives the base 1 and the swing mechanism 4 to move forward through the leg assembly 5. Among them, 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 posture support member 12 abuts against the swing mechanism 4. This structure shortens the time required for the lying posture support member 12 to abut against the swing mechanism 4 and improves the reliability of their abutment by reducing the height of the base 1 relative to the swing mechanism 4.

[0179] During the transformation of the mechanical extension structure 100 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. Among them, 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 member 12 is separated from the swing mechanism 4. This structure realizes increasing the time required for the lying support member 12 to be separated from the swing mechanism 4 and improving the reliability of the separation by raising the height of the base 1 relative to the swing mechanism 4.

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

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

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

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

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

[0185] When the user's buttocks sit on the seat unit where the mechanical extension structure 100 is 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 posture support member 311 will support the base 1 through the swing mechanism 4 to enable the base to provide a 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 above the seat cushion structure 300.

[0186] In this embodiment, the mechanical extension structure 100 further includes a tension spring (not marked). The end of the tension spring is provided with a hook (not marked), and a flexible sound-absorbing member (not marked) is provided on the outer wall of the hook. The hardness of the flexible sound-absorbing member is less than that 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 sound-absorbing member is clamped between the hook at one end of the tension spring and the swing mechanism 4, and a flexible sound-absorbing member 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 further includes a tension spring. The end of the tension spring is provided with a hook, and a flexible sound-absorbing member is provided on the outer wall of the hook. The hardness of the flexible sound-absorbing member is less than that 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 sound-absorbing member is clamped between the hook at one end of the tension spring and the swing mechanism, and a flexible sound-absorbing member 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 the sitting position, the tension spring undergoes elastic deformation and is in a stretched state; when the mechanical extension structure 100 is in the lying position, the tension spring undergoes elastic deformation and is in a stretched state; the axial length dimension of the tension spring in the lying position is greater than the axial length dimension 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 the sitting position and the lying position; when the mechanical extension structure 100 is in the lying position, the user places the legs on the leg rest structure. At this time, the leg rest structure transfers more gravity to the swing mechanism 4 through the leg component 5. Therefore, the axial length dimension of the tension spring in the lying position is greater than the axial length dimension of the tension spring in the sitting position, so that the tension spring can maintain the stability of the swing mechanism 4 through its greater tensile force.

[0190] More preferably, when the mechanical extension structure 100 is in the TV position, the tension spring does not undergo elastic deformation; the axial length dimension of the tension spring in the lying position is greater than the axial length dimension of the tension spring in the sitting position, and the axial length dimension of the tension spring in the sitting position is greater than the axial length dimension of the tension spring in the TV 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, 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 tensile force, so as to prevent the seat cushion structure 300 from moving relative to the armrest structure when the user sits on the seat cushion structure 300.

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

[0193] When the mechanical extension structure 100 is in the lying position, the other end of the first swing rod 45 is behind the other end of the second swing rod 44, and the other end of the third swing rod 47 is behind the other end of the fourth swing rod 46. One sitting posture support member 311 is separated from the first swing rod 45, and the other sitting posture support member 311 is separated from the third swing rod 47.

[0194] Users usually adjust the mechanical extension structure 100 of the seat unit to the lying position only during entertainment time. Most of the time, the mechanical extension structure 100 of the seat unit is in the sitting position. Therefore, the mechanical extension structure 100 can provide more stable support for the swing mechanism 4 through the two sitting posture support members 311.

[0195] As Figure 13 shown, the first swing rod 45 is provided with a front sitting posture limit groove 451 that is recessed inward, and the third swing rod 47 is provided with a rear sitting posture limit groove 471 that is recessed inward. When the mechanical extension structure 100 is in the sitting position, one sitting posture support member 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 member 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 posture limit groove 451 restricts the movement of one sitting posture support member 311, and the rear sitting posture limit groove 471 restricts the movement of the other sitting posture support member 311, thereby preventing the swing mechanism 4 from collapsing relative to the base 3. Therefore, the provision of the front sitting posture limit groove 451 and the rear sitting posture limit groove 471 is, to a certain extent, equivalent to providing a "locking" structure for preventing deformation of the swing mechanism 4, so as to further prevent the seat cushion structure 300 from moving relative to the armrest structure when the user is sitting above the seat cushion structure 300.

[0197] In other embodiments, adopting the first swing mechanism, the mechanical extension structure further includes a sitting posture support member. When the mechanical extension structure is in the sitting position, the other end of the first swing rod is in front of the other end of the second swing rod, and the other end of the third swing rod is in front of the other end of the fourth swing rod. The sitting posture support member 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 behind the other end of the second swing rod, and the other end of the third swing rod is behind the other end of the fourth swing rod. The sitting posture support member is separated from the first swing rod;

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

[0199] As Figure 15 shown in the figure, when the second swing mechanism 4 is adopted, the mechanical extension structure 100 further includes a sitting position support member 311. When the mechanical extension structure 100 is in the sitting position, the other end of the first swing rod 45 is in front of the other end of the second swing rod 44, the other end of the third swing rod 47 is in front of the other end of the fourth swing rod 46, and the sitting position support member 311 is located below the first connecting rod 41 and 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 behind the other end of the second swing rod 44, the other end of the third swing rod 47 is behind the other end of the fourth swing rod 46, and the sitting position support member 311 is separated from the second connecting rod 42.

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

[0201] As Figure 12 shown in the figure, the mechanical extension structure 100 further includes a lying position support member 12. The lying position support member 12 is fixedly connected to the base 1. When the mechanical extension structure 100 is in the lying position, the lying position support member 12 is located above the second support rod 49 and abuts against the second support rod 49; when the mechanical extension structure 100 is in the sitting position, the lying position support member 12 is separated from the second support rod 49.

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

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

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

[0205] When the user's buttocks are sitting above the seat cushion structure 300 and the mechanical extension structure 100 is in the sitting position, the seat cushion structure 300 provides a downward force on the second support rod 49 through the base 1. Since the rotational connection of the other end of the second support rod 49 and the third link 43 is above the rotational connection of the other end of the fourth swing rod 46 and the third link 43, therefore, the "rotational connection of the other end of the second support rod 49 and the third link 43" applies a downward thrust to the "rotational connection of the other end of the fourth swing rod 46 and the third link 43", so as to realize that the fourth swing rod 46 pulls the third swing rod 47 downward to abut against the sitting posture support member 311. This structure further improves the reliability of the sitting posture support member 311 in supporting the swing mechanism 4.

[0206] In this embodiment, the rotational connection of the other end of the first support rod 48 and the third link 43 is above the rotational connection of the other end of the second support rod 49 and the third link 43. As Figure 4 shown, the "rotational connection of the other end of the first support rod 48 and the third link 43" is slightly higher than the "rotational connection of the other end of the second support rod 49 and the third link 43". Therefore, the swing mechanism 4 makes the user feel that their buttocks sink into the seat unit and they lean slightly backward by slightly raising the height of the front side of the base 1, that is, raising the height of the user's legs.

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

[0208] The third link 43 provides a downward pulling force on the first swing rod 45 through the second swing rod 44. Therefore, the first reinforcing rib is used to increase the anti-deformation ability of the second swing rod 44; the third link 43 provides a downward pulling force on the third swing rod 47 through the fourth swing rod 46. Therefore, the second reinforcing rib is used to increase the anti-deformation ability of the fourth swing rod 46.

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

[0210] When the sitting posture support member 311 is located on one side of the second swing rod 44 and the first reinforcing rib is located on the other side of the second swing rod 44, the first reinforcing rib will not interfere with the sitting posture support member 311 during the movement of the second swing rod 44; when the sitting posture support member 311 is located on one side of the fourth swing rod 46 and the second reinforcing rib is located on the other side of the fourth swing rod 46, the second reinforcing rib will not interfere with the sitting posture support member 311 during the movement of the fourth swing rod 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 further includes at least one sitting posture support member 311. When the mechanical extension structure 100 is in the sitting posture position, the sitting posture support member 311 is located below the first support rod 48 and abuts against the first support rod 48; and / or, the sitting posture support member 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 the lying posture position, the sitting posture support member 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 members 311. When one sitting posture support member 311 is located below the first support rod 48 and this sitting posture support member 311 abuts against the first support rod 48, one sitting posture support member 311 provides a supporting force for the base 1 through the first support rod 48; when the other sitting posture support member 311 is located below the second support rod 49 and this sitting posture support member 311 abuts against the second support rod 49, the other sitting posture support member 311 provides a supporting 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] As Figure 12 shown, the base 3 includes two armrest plates 31 and a cross beam tube 32. The two armrest plates 31 are directly or indirectly connected as a whole through the cross beam tube 32; for the first swing rod mechanism 4 and the second swing rod structure 4: the first swing rod 45 and the third swing rod 47 are respectively rotatably connected to the armrest plate 31, and the armrest plate 31 is fixedly connected to the armrest structure; for the third swing rod structure 4: the other end of the support rod 48 and the other end of the second support rod 49 are respectively rotatably connected to the armrest plate 31.

[0215] In other embodiments, the base includes a metal frame, such as a U-shaped metal frame, an I-shaped metal frame, a quadrilateral metal frame, an oval metal frame, a hexagonal metal frame, etc.; for the first swing rod mechanism and the second swing rod structure: the first swing rod and the third swing rod are respectively rotatably connected to the annular metal frame, and the annular metal frame is fixedly connected to the armrest structure; for the third swing rod 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] As Figure 4and Figure 12 As shown in the figure, 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 lead screw, and a pushing block. The driver is fixedly connected to the base. A driving rod fixedly connected to the lead screw is provided on the driver. The pushing block is threadedly connected to the lead screw, and the leg assembly is directly or indirectly rotatably connected to the pushing block.

[0217] Preferably, the driver 61 is rotatably connected to the cross beam tube 32; as Figure 12 shown in the figure, the base 3 includes two armrest plates 31 for connecting the sofa armrests and a cross beam tube 32. The two armrest plates 31 are directly or indirectly integrated through the cross beam tube 32, and the armrest plates 31 are fixedly connected to the armrest structure.

[0218] In the prior art, during the process of the mechanical extension structure changing from the lying position to the sitting position, the driving device drives the leg assembly to move and retracts it under the base. However, during the movement of the leg assembly, it is easy to pinch the user's fingers or other parts of the body.

[0219] In this embodiment, an anti-pinch sensor (not marked) is provided on the leg assembly 5. When the anti-pinch sensor detects that the user's body is pinched between 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 disconnects the power supply of the driving device 6 through the controller 81, or controls the driving device 6 to move in the reverse direction through the controller 81; preferably, one of the rear leg rotating plate 54 and the front leg 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] As Figure 1 shown in the figure, the first structure of the backrest assembly 2 includes a backrest plate 21, a front backrest bracket 22, a rear 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, and the other end of the front backrest bracket 22 is rotatably connected to the base 1. One end of the rear backrest bracket 23 is rotatably connected to the backrest plate 21, the rear 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 rear backrest bracket 23, and the other end of the backrest driving rod 24 is rotatably connected to the base 3;

[0221] During the process of the mechanical extension structure 100 changing 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 rear backrest bracket 23, and a backrest drive rod 24. One end of the front backrest bracket 22 is rotatably connected to the backrest plate 21, and the other end of the front backrest bracket 22 is fixedly connected to the base 1. One end of the rear backrest bracket 23 is rotatably connected to the backrest plate 21, and the rear backrest bracket 23 is rotatably connected to the base 1. One end of the backrest drive rod 24 is rotatably connected to the other end of the rear backrest bracket 23, and the other end of the backrest drive rod 24 is rotatably connected to the base 3;

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

[0224] As Figure 16 shown, the third structure of the backrest assembly 2 includes a backrest plate 21, a front backrest bracket 22, a rear backrest bracket 23, a backrest connection bracket 25, and a backrest drive rod 24. One end of the front backrest bracket 22 is rotatably connected to the backrest plate 21, and the other end of the front backrest bracket 22 is fixedly connected to the base 1. One end of the rear backrest bracket 23 is rotatably connected to the backrest plate 21, and the other end of the rear backrest bracket 23 is rotatably connected to one end of the backrest connection bracket 25. The backrest connection bracket 25 is rotatably connected to the base 1. One end of the backrest drive rod 24 is rotatably connected to the other end of the backrest connection bracket 25, and the other end of the backrest drive rod 24 is rotatably connected to the base 3;

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

[0226] The three types of backrest assemblies 2 are used for different seat units: the first type of backrest assembly 2 is mainly used for seat units with zero wall contact and zero rubbing of the back (during the process of the mechanical extension structure 100 changing from the sitting position to the 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 to reduce the displacement difference generated between the backrest structure 200 and the user's back); the second type of backrest assembly 2 is mainly used to increase the amplitude of the backrest structure 200 reclining; the third type of backrest assembly 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. The seat unit includes a backrest structure, a seat cushion structure, and a mechanical extension structure. A user's buttocks can sit above the seat cushion structure, and the user's back can lean against the front of the backrest structure. Among them, 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. During 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 recline relative to the seat cushion structure; during 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 upright position relative to the seat cushion structure. However, during the movement of the backrest structure relative to the seat 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] In Figure 9 this utility model discloses a seat unit. The seat unit includes a backrest structure 200, a seat cushion structure 300, and a mechanical extension structure 100. The mechanical extension structure 100 includes a base 1 for installing the seat cushion structure 300 and a backrest assembly 2 for installing 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. An installation member (not marked) is provided on the backrest frame 2001. The backrest elastic member 2002 is arranged on the backrest frame 2001. The backrest filler 2003 is arranged in the backrest decorative cover 2004. 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 an 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 in the seat cushion decorative cover 3004. 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 an elastic support force for the seat cushion decorative cover 3004;

[0231] The backrest assembly 2 adopts a first structure, that is, the backrest assembly 2 includes a backrest plate 21, a front backrest bracket 22, and a rear backrest bracket 23. The backrest plate 21 is detachably inserted into the installation member. One end of the front backrest bracket 22 is rotatably connected to the backrest plate 21, and the other end of the front backrest bracket 22 is rotatably connected to the base 1. One end of the rear backrest bracket 23 is rotatably connected to the backrest plate 21, and the rear backrest 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 plate 21 is inserted into the mounting member, 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 surface of the backrest decorative cover 2004 and the front surface 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 surface of the seat cushion decorative cover 3004 and one end surface 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. Among them, 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 at the middle position of one of the serpentine springs.

[0235] The serpentine spring provides support for the seat cushion decorative cover 3004 and the seat 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 seat cushion decorative cover 3004 and the seat cushion filler 3003 through the serpentine spring. This structure is used to increase the service life of the seat 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, preferably, the elastic band is 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 the two ends of the elastic band are arranged on the left side of the seat cushion frame 3001. In this solution, preferably, the elastic band is arranged at the middle position of one of the serpentine springs.

[0238] Preferably, a backrest cavity is provided on the backrest frame 2001, and a mounting member is provided on the wall of the backrest frame 2001 located in the backrest cavity. The backrest plate 21 is detachably inserted into the mounting member. When the backrest plate 21 is inserted into the mounting member, since the mounting member is located in the backrest cavity, at least part of the backrest plate 21 is located in the backrest cavity. This structure prevents the user's fingers from reaching into the gap between the backrest plate 21 and the mounting member to achieve the purpose of anti-pinch 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 outside the backrest structure 200. This structure reduces the probability of direct contact between the user's fingers and the backrest assembly 2, so as to achieve the purpose of preventing pinching of the seat unit.

[0240] When the backrest plate 21 is inserted into the mounting member and the backrest decorative cover 2004 abuts against the seat cushion decorative cover 3004, the difficulty for the user's fingers to pass through the gap between the backrest decorative cover 2004 and the seat cushion decorative cover 3004 will be increased. When the backrest plate 21 is inserted into the mounting member and the front backrest bracket 22 abuts against the seat cushion decorative cover 3004, the difficulty for the user's fingers to enter the gap between the front backrest bracket 22 and the seat cushion decorative cover 3004 will be increased.

[0241] In the prior art, after a user sits on the seat unit for a long time, the body will feel a certain degree of fatigue, which results in a decline in the user experience of the seat unit.

[0242] Preferably, the backrest structure 200 further includes a massager (not marked). The massager is located within the backrest decorative cover 2004, and the periphery of the massager is surrounded by the backrest filling 2003. Among them, the backrest filling 2003 is mainly used to support the massager and to define the position of the massager within the backrest structure 200. Therefore, more preferably, the massager is fixedly connected to the backrest filling 2003.

[0243] To avoid affecting the massage effect of the massager, in this embodiment, the periphery of the massager is fixed to the backrest filling 2003, and the front surface of the massager corresponds to and is in direct contact with 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 for 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 force, etc. of the massager to increase the massage comfort of the massager. When the controller 81 is electrically connected to a massager, preferably, the controller 81 is provided on the switch seat. When the controller 81 is provided on the switch seat, all functions on the controller 81 can be integrated on the switch seat and controlled through the switch seat. That is, buttons for the controller are provided on the switch seat, and the buttons control the vibration frequency, vibration amplitude, vibration force, etc. of the massager through the controller 81.

[0246] When L11 is greater than L3, regardless of how the front backrest bracket 22 rotates relative to the base 1, the front backrest bracket 22 will not move to the front of the front surface of the backrest decorative cover 2004; when L21 is greater than L3, regardless of how the front backrest bracket 22 rotates relative to the base 1, the front backrest bracket 22 will not move above one end surface of the seat cushion decorative cover 3004. Since the front backrest bracket 22 will not move to the front of the front surface of the backrest decorative cover 2004 and the front backrest bracket 22 will not move above one end surface of the seat cushion decorative cover 3004, therefore, 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 front backrest bracket 22, so as to achieve the purpose of preventing the seat unit from pinching.

[0247] In Figure 9 it, the maximum deformation distance between the front surface of the backrest decorative cover 2004 and the front surface of the backrest frame 2001 is L13, L13 is greater than L3, and the maximum deformation distance between one end surface of the seat cushion decorative cover 3004 and one end surface of the seat cushion frame 3001 is L23, L23 is greater than L3.

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

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

[0250] When L13 is greater than L3, during the rotation of the front backrest bracket 22 relative to the base 1, the probability that the front backrest bracket 22 pierces the backrest decorative cover 2004 will become smaller; when L23 is greater than L3, during the rotation of the front backrest bracket 22 relative to the base 1, the probability that the front backrest bracket 22 pierces the seat cushion decorative cover 3004 will become smaller. This structure enables the seat unit to have the anti-pinch function and the service life will also increase accordingly.

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

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

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

[0257] Such as Figure 1and Figure 9 As shown in Figure 9 , a limiting rod 11 is provided on the base 1. When the mechanical extension structure 100 is in the sitting position, the back surface of the front backrest bracket 22 abuts against the limiting rod 11; as Figure 2 and Figure 3 shown in Figure 3 , during the process of the mechanical extension structure 100 changing from the TV position to the lying position, the backrest plate 21 pushes the front backrest bracket 22 to rotate clockwise, so that the front backrest bracket 22 separates 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 surface of the front backrest bracket 22 abuts against the limiting rod 11, the limiting rod 11 is used to prevent the front backrest bracket from rotating counterclockwise; since the limiting rod 11 prevents the front backrest bracket 22 from rotating counterclockwise, therefore, the front backrest bracket 22 cannot drive the backrest plate 21 to move away from the front backrest bracket 22, that is to say, when the mechanical extension structure 100 is in the sitting position, the front backrest bracket 22 cannot drive the backrest plate 21 to move further. This structure is preferably used to achieve zero-wall contact of the sofa unit.

[0259] During the process of the mechanical extension structure 100 changing from the TV position to the lying position, the front backrest bracket 22 separates from the limiting rod 11, and the front backrest bracket 22 squeezes the seat cushion decorative cover 3004; since the seat cushion filler 3003 is arranged in the seat cushion decorative cover 3004 and the seat cushion filler 3003 can deform, therefore, during the process of the front backrest bracket 22 squeezing the seat cushion decorative cover 3004, the seat cushion filler 3003 makes the seat cushion decorative cover 3004 always abut against the front backrest bracket 22 through its own deformation. This structure effectively prevents the user's fingers or other parts of the body from accidentally getting into the gap between the front backrest bracket 22 and the seat cushion decorative cover 3004 during the process of the front backrest bracket 22 rotating 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 decorative cover 3004 and the seat cushion filler 3003 are clamped between the front backrest bracket 22 and the base 1. When the seat cushion decorative cover 3004 and the seat cushion filler 3003 are clamped between the front backrest bracket 22 and the base 1, it will be difficult for the user's fingers to get into the gap between the front backrest bracket 22 and the base 1.

[0261] Preferably, the seat cushion decorative cover 3004 is detachably arranged on the seat cushion frame 3001. For example, the seat cushion decorative cover 3004 is hung on the seat cushion frame 3001, the seat cushion decorative cover 3004 is snap-connected with the seat cushion frame 3001, and the seat cushion decorative cover 3004 is connected with 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 backrest bracket 22 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 damaged by being clamped between the front backrest bracket 22 and the base 1) and replace it with a new seat cushion decorative cover 3004 for the seat unit.

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

[0264] When the back surface of the front backrest bracket 22 abuts against the limit sleeve 112 and the hardness of the limit sleeve 112 is different from that of the front backrest bracket 22, there is no gap between the front backrest bracket 22 and the limit sleeve 112. This structure can prevent the user's fingers or other parts of the body from reaching into the gap between the front backrest bracket 22 and the limit sleeve 112, so as to achieve the purpose of preventing pinching of the seat unit.

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

[0266] Preferably, a backrest limit groove (not marked) matching the limit sleeve 112 is provided on the back surface of the front backrest bracket 22. When the back surface of the front backrest bracket 22 abuts against the limit sleeve 112, the limit sleeve 112 is inserted into the backrest limit groove and abuts against the groove wall of the backrest limit groove. During the process of the mechanical extension structure 100 changing from the sitting position to the TV position, the backrest limit groove is used to prevent the limit sleeve 112 from sliding relative to the front backrest bracket 22, so as to further improve the anti-pinching 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 backrest bracket 22 and the base 1 is A2, the distance between A1 and A2 is L4, and the width dimension of half of the front backrest bracket 22 is L5. L4 is greater than L5; during the process of the mechanical extension structure changing from the TV position to the lying position, the angle between the back surface of the front backrest bracket and the horizontal plane is less than 90°.

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

[0269] In this embodiment, when the mechanical extension structure 100 is in the sitting position, the angle between the back surface 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 surface 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 surface of the front backrest bracket and the horizontal plane is greater than 90°, the limiting 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 plate, when the limiting rod supports the front backrest bracket, the front backrest bracket will not drive the backrest frame to move backward through the backrest plate; this structure effectively increases the reliability of the backrest structure to support the user's back when the user sits on the seat unit (the mechanical extension structure of the seat unit is in the sitting position).

[0270] As Figure 2 and Figure 3 shown, when the angle between the back surface of the front backrest bracket 22 and the horizontal plane is less than 90° during the process of the mechanical extension structure 100 changing from the TV position to the lying position, the front backrest bracket 22 rotates clockwise and necessarily 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 drive rod 24. One end of the backrest drive rod 24 is rotatably connected to the other end of the rear backrest bracket 23. The mechanical extension structure 100 further includes a base 3. The base 3 is located below the base 1. The other end of the backrest drive rod 24 is rotatably connected to the base 3;

[0272] wherein, when the mechanical extension structure 100 is in the sitting position, the backrest drive rod 24 is vertically arranged and inclined forward, as Figure 5 shown; during the process of the mechanical extension structure 100 changing from the sitting position to the TV position, the backrest drive rod 24 rotates clockwise relative to the base 3, as Figure 5 and Figure 6 shown; during the process of the mechanical extension structure 100 changing from the TV position to the lying position, the rear backrest bracket 23 rotates clockwise relative to the backrest drive rod 24, and the rear backrest bracket 23 pushes the base 1 forward and upward, 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 the sitting position and the backrest drive rod 24 is vertically arranged and inclined forward, the backrest drive rod 24 rotates clockwise to control the movement direction of the driving device 6.

[0274] When the mechanical extension structure 100 is transformed from the sitting position to the TV position, the backrest drive rod 24 rotates clockwise relative to the base 3. This structure can ensure that the backrest structure 200 does not fall backward during the transformation from the sitting position to the TV position, that is, the zero-wall contact of the seat unit is realized.

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

[0276] The annular groove 2411 is used to define the hanging position of the tension spring on the mounting rod 241. By preventing the hook on the tension spring from sliding relative to the mounting rod 241, it is avoided that the fingers or other parts of the user's body extend into the gap between the hook and the mounting rod 241.

[0277] In other embodiments, the mechanical extension structure further includes a tension spring. The end of the tension spring is provided with a hook, and the base is provided with a mounting rod. The tension spring is hung on the mounting rod through the hook. Compared with the backrest drive rod, the base has the advantage of a fixed position. Therefore, hanging the tension spring on the mounting rod of the base reduces the variable factors affecting the operation of the tension spring and improves the reliability of the tension spring operation.

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

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

[0280] The height dimension of the existing floor sweeping robot is usually 8 cm - 15 mm. Therefore, when the height of at least two support rods ≥ 9 cm, the floor 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 oval 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, and the floor 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, and the floor sweeping robot can enter the bottom of the seat unit from all directions of the seat unit.

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

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

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

[0286] When the mechanical extension structure 100 is in the sitting position, the sitting posture support member 311 abuts against the first swing rod 45; therefore, setting the fourth reinforcing rib on the first swing rod 45 can increase the anti-deformation ability 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 posture support member 311 abuts against the third swing rod 47; therefore, setting the fifth reinforcing rib on the third swing rod 47 can increase the anti-deformation ability 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 backrest bracket 22 is rotatably connected to the backrest plate 21, a first sound insulation gasket (not marked) is clamped between one end of the front backrest bracket 22 and the backrest plate 21; and / or, when the other end of the front backrest bracket 22 is rotatably connected to the base 1, a second sound insulation gasket (not marked) is clamped between the other end of the front backrest bracket 22 and the base 1.

[0289] In this embodiment, when one end of the rear backrest bracket 23 is rotatably connected to the backrest plate 21, a third sound insulation gasket (not marked) is clamped between one end of the rear backrest bracket 23 and the backrest plate 21; and / or, when the rear backrest bracket 23 is rotatably connected to the base 1, a fourth sound insulation gasket (not marked) is clamped between the rear backrest bracket 23 and the base 1.

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

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

[0292] And / or, a plurality of seat frame hooks (not marked) are provided on the seat cushion frame 3001, 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 (not marked) 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 that the end of the backrest elastic member 2002 slides relative to the backrest hook, that is, the flexible backrest member prevents a user's finger or other part of the body from reaching between the end of the backrest elastic member 2002 and the backrest hook, so as to achieve the purpose of preventing pinching of the seat unit.

[0294] The flexible seat frame member is used to reduce the probability that the end of the seat cushion elastic member 3002 slides relative to the seat frame hook, that is, the flexible seat frame member prevents a user's finger or other part of the body from reaching between the end of the seat cushion elastic member 3002 and the seat frame hook, so as to achieve the purpose of preventing pinching of the seat unit.

[0295] 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 chute is provided on the backrest frame, at least two hooks are connected together to form a slider, and the slider is slidably inserted into the chute; after at least two hooks are connected together to form a slider, the slider can facilitate the backrest frame to replace sliders with different numbers of hooks, that is, different seat units can adopt different numbers of hooks to meet the needs of backrest structures to support users of different weights.

[0296] In this embodiment, the backrest decorative cover 2004 is hung on the backrest frame 2001, and the seat cushion decorative cover 3004 is hung on the seat cushion frame 3001.

[0297] After the seat unit has been used for a long time, the distribution of the backrest filling 2003 within the backrest decorative cover 2004 will become uneven, and the distribution of the seat cushion filling 3003 within the seat cushion decorative cover 3004 will also become uneven. Therefore, when the backrest decorative cover 2004 is hung on the backrest frame 2001, the backrest decorative cover 2004 can be detached 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 detached from the seat cushion frame 3001 and replaced.

[0298] Preferably, the backrest plate 21 made of metal is snap-connected to the mounting member made of metal, the backrest frame 2001 made of plastic is fixedly connected to the mounting member by a fastener (not marked), and the width dimension of the backrest hook made of plastic is three times or more the width dimension of the end of the backrest elastic member 2002.

[0299] The existing backrest frame is made of wood, while in the present utility model, 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. 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 the width dimension of the end of the backrest elastic member 2002" is used to enhance the self-strength of the backrest hook and prevent the backrest hook from being broken by the backrest elastic member 2002 after the seat unit has been 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 ≥ 3 times the width dimension of the end of the backrest elastic member 2002 can reduce the probability of the backrest hook being broken and the probability of the backrest elastic member 2002 being broken.

[0300] In this embodiment, a decorative cover hook is provided on the backrest frame 2001 for hanging the backrest decorative cover 2004; in the prior art, for the backrest frame made of wood, a threaded hole needs to be opened on its wall by a power tool, and the fastener is engaged 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 with the backrest frame. Even if the decorative cover hook is installed on the backrest frame 2001 made of plastic by other means, the installation difficulty of the decorative cover hook on the plastic backrest frame 2001 is much lower than that on the wooden backrest frame 2001; therefore, the backrest frame 2001 made of plastic will be the first choice for adapting to different seat units for a long time to come, especially the backrest frame 2001 for hanging the backrest decorative cover 2004.

[0301] 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.

[0302] Preferably, the seat cushion frame 3001 is provided with a first mounting surface and a second mounting surface, and the base 1 is provided with a mounting plate located below the upper end surface of the base 1. When the seat cushion structure 300 is mounted 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.

[0303] 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.

[0304] 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;

[0305] Wherein, the control switch 7 is provided 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 provided on the side of the armrest structure, and the control switch 7 is inclined.

[0306] When the control switch 7 is provided 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 impacted by an external force becomes smaller, so as to increase the service life of the control switch 7.

[0307] In addition, when the control switch 7 is provided 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 key 71 and the second key 73 being accidentally touched.

[0308] When the control switch 7 is provided on the side of the armrest structure and the control switch 7 is inclined, the user's fingers can naturally bend to press the first key 71 and the second key 73, so as to improve the comfort of pressing the keys.

[0309] A power socket and a wire bundling channel are provided on the armrest frame. The switch base is provided in the wire bundling channel. The key is connected to a switch power cord, and the switch power cord is electrically connected to the power socket. When the key is electrically connected to the power socket through the switch power cord, the switch power cord is located in the wire bundling channel.

[0310] The armrest frame is provided with a wire bundling channel to prevent the switch power cord from moving within the seat unit. During the process of the mechanical extension structure changing from the sitting position to the lying position (or, during the process of the mechanical extension structure changing from the lying position to the sitting position), the wire bundling channel prevents the switch power cord from moving onto the movement path of the mechanical extension structure.

[0311] The sofa includes at least two seat units as described in this embodiment. A frame is provided on the mechanical extension structure 100, and the frames on adjacent seat units are fixedly connected in a snap-fit manner.

[0312] When the sofa includes two seat units, the frame is provided on the armrest structure, and the armrest structures on adjacent seat units are fixedly connected in a snap-fit manner; when the sofa includes three seat units, the frame of the leftmost seat unit is provided on the armrest structure, the frame of the rightmost seat unit is provided on the armrest structure, and the frame of the seat unit in the middle position is not provided on the armrest structure.

[0313] 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 moving the sofa; for example, a three-seat sofa can be carried by one worker, a three-seat sofa can enter an elevator, and a three-seat sofa can pass through a door.

[0314] When the sofa includes two seat units and is a structure without armrests, four flexible support rods are provided under the base, that is, the support function of the armrest structure for the seat unit is replaced by the flexible support rods.

[0315] 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 make the frames on adjacent seat units snap-fit.

[0316] The sofa includes at least two seat units as described in this embodiment. An armrest structure is provided on the mechanical extension structure 100. The armrest structure includes an armrest frame, armrest filler, and armrest decorative cover. The armrest filler is provided in the armrest frame through the armrest decorative cover. When the armrest filler is provided in 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.

[0317] When the upper width of the armrest structure is greater than the lower width of the armrest structure, the contact area between the upper part of the armrest structure and the user's arm can be increased to enhance the comfort of the user sitting on the seat unit.

[0318] Preferably, the armrest structure further includes a charging base and a power cord. The charging base is provided with a charging interface, the charging base is fixedly connected to the armrest frame, and the armrest frame is provided with a wire bundling channel. The power cord is electrically connected to the charging interface through the wire bundling channel.

[0319] 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 touching of the control switch and improve the aesthetics of the sofa.

[0320] The seat unit includes an armrest structure, a backrest structure 200, a seat cushion structure 300, a leg rest structure, and a mechanical extension structure 100. The mechanical extension structure 100 includes the mechanical extension structure described in this embodiment. The armrest board 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 seat cushion structure 300 is fixedly connected to the base 1. Among them, a ventilation structure and / or a heating structure is provided on the backrest structure 200.

[0321] In this embodiment, the ventilation structure is for blowing air to the user's back, and the heating structure is for heating the user's back. Since the present utility model does not improve the ventilation structure and the heating structure, the ventilation structure and the heating structure will not be described in detail.

[0322] Preferably, a ventilation structure and / or a heating structure is also provided on the seat cushion structure 300.

[0323] In this embodiment, the upper, lower, front, and rear orientations of the seat unit are based on Figure 9 the direction indicated by the arrow in the figure.

[0324] The above is only an illustration of the best embodiment of the present utility model, but it should not be construed as a limitation of the claims. The present utility model is not limited to the above embodiments, and all changes made within the protection scope of the independent claims of the present utility model are within the protection scope of the present utility model.

Claims

1. A mechanical extension structure, comprising a base, a pedestal, a backrest assembly, a leg assembly, a swing mechanism and a driving device. The pedestal is movably connected to the base through the swing mechanism. The leg assembly is movably arranged on the pedestal, the backrest assembly is movably arranged on the pedestal, the driving device is arranged on the base, and the mechanical extension structure has a sitting position and a lying position; It is characterized in that The mechanical extension structure further comprises a control switch, the control switch includes two on-off keys and a switch base. The switch base is provided with two common terminals, two normally closed terminals and two normally open terminals. Each on-off key is connected to one of the common terminals and one of the normally closed terminals, or the on-off key is connected to one of the common terminals and one of the normally open terminals; Wherein, 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, both of the two normally closed terminals are connected to the negative pole of the power supply, both of the two normally open terminals are connected to the positive pole of the power supply. During the process of the mechanical extension structure changing from the sitting position to the lying position, one of the on-off keys is connected to one of the common terminals and one of the normally open terminals, and the other on-off key is connected to the other common terminal and the other normally closed terminal; during the process of the mechanical extension structure changing from the lying position to the sitting position, one of the on-off keys is connected to one of the common terminals and one of the normally closed terminals, and the other on-off key is connected to 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 storage battery, and the two normally open terminals are respectively electrically connected to the positive pole of the storage battery.

3. The mechanical extension structure according to claim 2, characterized in that, When the power supply includes an external power supply and a storage battery, the mechanical extension structure further comprises a controller, a protection switch and a sensor. The positive pole of the storage battery is electrically connected to the controller through the sensor, the storage 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 storage battery and the external power supply.

4. The mechanical extension structure according to claim 1, wherein 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.

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

6. The mechanical extension structure according to claim 1, wherein, The mechanical extension structure further comprises at least one charging socket, at least one charging socket is arranged on the switch base, and the charging socket includes a Type-C interface.

7. Seat unit, characterized in that, Including the mechanical extension structure according to any one of claims 1-6, the leg assembly includes a main leg mounting plate, a front leg rotating plate, a rear leg rotating plate, a front leg connecting plate and a rear leg connecting plate. One end of the front leg rotating plate and one end of the rear leg rotating plate are respectively rotatably connected to the main leg mounting plate. The other end of the front leg rotating plate is rotatably connected to one end of the front foot connecting plate. The other end of the rear leg rotating plate is rotatably connected to one end of the rear leg connecting plate. The other ends of the front leg connecting plate and the rear leg connecting plate are respectively rotatably connected to the pedestal; Wherein, one of the rear leg rotating plate and the front leg connecting plate is provided with a leg support mechanism. When the mechanical extension structure is in the lying position, the leg support mechanism abuts against the other one of them.

8. The seat unit according to claim 7, characterized in that, The seat unit further includes a main leg rest structure, which includes a main leg rest plate and a main leg rest decorative cover. The main leg rest plate is fixedly connected to the main leg rest mounting plate, and the main leg rest decorative cover is detachably arranged on the main leg rest plate.

9. The seat unit according to claim 8, characterized in that, The main foot rest decorative cover is hung on the main leg rest plate; or, a first opening is provided on the main foot rest decorative cover, the main leg rest plate is placed into the main foot rest decorative cover through the first opening, and a first sealing structure is provided at the first opening of the main foot rest decorative cover. The first sealing structure includes one of a first straight zipper, a first arc zipper, and a first snap structure.

10. The seat unit according to claim 7, characterized in that The leg assembly further includes a secondary leg rest mounting plate and a rear leg rest extension plate. One end of the main leg rest mounting plate and one end of the rear leg rest extension plate are respectively rotatably connected to the secondary 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 rotating plate. Or, the leg assembly further includes a secondary 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 secondary 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, and 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 seat unit according to claim 10, characterized in that, The seat unit further includes a secondary leg rest structure, which includes a secondary leg rest plate and a secondary leg rest decorative cover. The secondary leg rest plate is fixedly connected to the secondary leg rest mounting plate, and the secondary leg rest decorative cover is detachably arranged on the secondary leg rest plate.

12. The seat unit according to claim 11, characterized in that, The secondary foot rest decorative cover is hung on the secondary leg rest plate; or, a second opening is provided on the secondary foot rest decorative cover, the secondary leg rest plate is placed into the secondary foot rest decorative cover through the second opening, and a second sealing structure is provided at the second opening of the secondary foot rest decorative cover. The second sealing structure includes one of a second straight zipper, a second arc zipper, and a second snap structure.

13. The seat unit according to claim 9 or 10, characterized in that, When the seat unit includes a main leg rest structure, the main leg rest plate is made of plastic, and the main leg rest plate is fixedly connected to the main leg rest mounting plate by screws or rivets; when the seat unit includes a secondary leg rest structure, the secondary leg rest plate is made of plastic, and the secondary leg rest plate is fixedly connected to the secondary leg rest mounting plate by screws or rivets.

14. The seat unit according to claim 7, characterized in that, 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 one end of the first swing rod, one end of the fourth swing rod is rotatably connected to one end of 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 seat unit according to claim 7, characterized in that, 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. One end of the second connecting rod is rotatably connected to the second swing rod.

16. The seat unit according to claim 14 or 15, characterized in that, 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. One of the first support rod and the first connecting rod is rotatably connected to the other end of the linkage rod.

17. The seat unit according to claim 14 or 15, characterized in that, 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. The front leg rest connecting plate and / or the rear leg rest connecting plate is rotatably connected to the transmission rod.

18. The seat unit according to claim 7, characterized in that, 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. 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 seat unit according to claim 18, characterized in that, The driving device includes a driver, a lead screw, a push block and a transmission structure. The driver is fixedly connected to the base. A driving rod fixedly connected to the lead screw is provided on the driver. The push block is threadedly connected to the lead screw; 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. The front leg rest connecting plate and / or the rear leg rest connecting plate is rotatably connected to the fourth transmission rod.

20. The seat unit according to claim 7, characterized in that, The swing mechanism includes a swing rod and a swing channel. The swing rod is provided on the base. The swing channel is provided on the base. 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.

21. The seat unit according to claim 20, characterized in that, The swing channel includes a horizontal section and / or an inclined section.

22. The seat unit according to claim 7, characterized in that, One of the front leg rest rotating plate and the rear leg rest rotating plate is provided with a lying position limiting groove for cooperating 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 seat unit according to claim 7, characterized in that, 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 ≤5 mm.

24. The seat unit according to claim 7, characterized in that, The seat unit further includes a seat cushion structure and an armrest structure. The base is fixedly connected to the seat cushion structure. The base is fixedly connected to the armrest structure; Wherein, the control switch is provided on the side of the seat cushion structure, and the control switch corresponds to the armrest structure; or, the control switch is provided on the side of the armrest structure, and the control switch is inclined.

25. The seat unit according to claim 7, characterized in that, 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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