Mechanical stretching device and seat

Abstract

The utility model discloses a mechanical stretching device and a seat. The mechanical stretching device comprises a base, and a sliding rail is assembled on the base; the seat frame assembly is connected to the sliding rail in a sliding mode and can slide front and back along the sliding rail; the backrest assembly is arranged at the rear end of the seat frame assembly, and when the seat frame assembly slides, the backrest assembly can rotate; the leg component is arranged at the front end of the seat frame component; the driving assembly is hinged to the leg assembly, and the driving assembly can drive the leg assembly to stretch out and draw back or drive the seat frame assembly to slide front and back along the sliding rail. According to the mechanical stretching device, the seat frame assembly is connected with the base through the sliding rail, so that the seat frame assembly can slide front and back along the sliding rail, and the stability and comfort of the mechanical stretching device during posture switching are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of furniture, in particular to a mechanical extension device and a seat. Background Art

[0002] With the development of society, people's quality of life is constantly improving, and the requirements for home life quality are also increasing. When faced with a wide variety of furniture, furniture with only a single function is difficult to effectively attract consumers' attention. Consumers often hope to maximize the utilization rate of furniture to obtain a better use experience.

[0003] Especially when purchasing seats, consumers generally pay attention to whether the seats can meet different usage needs, such as the ability to provide multiple usage modes such as sitting, reclining, and lying flat. Although seats with posture switching functions have appeared on the market, the seats have poor stability when switching postures, and are prone to jamming or interruption of movement, which seriously affects the comfort of the seats. Utility Model Content

[0004] In order to overcome at least one of the defects of the prior art described above, the utility model provides a mechanical extension device, which can improve the stability and comfort during posture switching.

[0005] A mechanical extension device according to an embodiment of the utility model includes: a base, on which a slide rail is installed; a seat frame assembly, which is slidably connected to the slide rail and can slide forward and backward along the slide rail; a backrest assembly, which is arranged at the rear end of the seat frame assembly and can rotate when the seat frame assembly slides; a leg assembly, which is arranged at the front end of the seat frame assembly; and a driving assembly, which is hinged to the leg assembly and can drive the leg assembly to extend and retract or drive the seat frame assembly to slide forward and backward along the slide rail.

[0006] In this mechanical extension device, the seat frame assembly is slidably connected to the slide rail on the base so that the seat frame assembly can slide back and forth along the slide rail, thereby optimizing the smoothness of the operation of the mechanical extension device and improving the stability and comfort of the mechanical extension device when switching postures.

[0007] According to some embodiments of the utility model, the leg assembly includes a leg mounting frame, a first leg link, a second leg link, a third leg link, a fourth leg link, a fifth leg link, a first foot pad mounting frame and a second foot pad mounting frame, the leg mounting frame is assembled at the front end of the seat frame assembly, the drive assembly is hinged to the first leg link, the first leg link is hinged between the front end of the leg mounting frame and the second leg link, the first foot pad mounting frame is hinged to an end of the second leg link away from the first leg link, the third leg link is hinged between the first foot pad mounting frame and the second foot pad mounting frame, the fourth leg link is hinged between the second foot pad mounting frame and the fifth leg link, the fourth leg link is hinged to the first leg link, and an end of the fifth leg link away from the fourth leg link is hinged to the rear end of the leg mounting frame.

[0008] According to some embodiments of the utility model, the backrest assembly includes a backrest mounting frame, a first backrest link, a second backrest link, a third backrest link, a fourth backrest link, a fifth backrest link and a back cushion mounting frame, the backrest mounting frame is assembled at the rear end of the seat frame assembly, the first backrest link is hinged at the front end of the backrest mounting frame and the front end of the back cushion mounting frame, the second backrest link is hinged between the first backrest link and the third backrest link, the fourth backrest link is hinged between the back cushion mounting frame and the third backrest link, the rear end of the back cushion mounting frame is hinged to the third backrest link, and the third backrest link is hinged to the rear end of the base through the fifth backrest link.

[0009] According to some embodiments of the utility model, the seat frame assembly includes a seat frame mounting frame and a linkage bracket, the linkage bracket is slidably connected to the slide rail, the seat frame mounting frame is assembled on the linkage bracket, the leg assembly is hinged to the front end of the seat frame mounting frame, and the backrest assembly is assembled at the rear end of the seat frame mounting frame.

[0010] According to some embodiments of the present invention, a plurality of linkage sliders are further included. The linkage sliders are pivotally connected to the linkage brackets, and the linkage sliders are slidably connected to the slide rails.

[0011] According to some embodiments of the utility model, the slide rail includes an ascending section and a straight section arranged in sequence along the front-to-back direction, the ascending section is inclined upward in a direction away from the straight section, the front end of the seat frame assembly is slidably connected to the ascending section, and the rear end of the seat frame assembly is slidably connected to the straight section.

[0012] According to some embodiments of the present invention, at least one limiting column is further included, and the limiting column is arranged between the rising section and the straight section.

[0013] According to some embodiments of the utility model, the driving assembly includes a driving unit, a first transmission link and a second transmission link, the driving unit is assembled on the base, the first transmission link is hinged between the driving unit and the second transmission link, and the second transmission link is fixedly connected to the leg assembly.

[0014] According to some embodiments of the present utility model, the driving unit includes a slider motor, the slider motor is equipped with a third transmission connecting rod, and the third transmission connecting rod is hinged to the first transmission connecting rod.

[0015] Based on the same inventive concept, the utility model also proposes a seat, comprising the mechanical extension device as described above.

[0016] In summary, the mechanical stretching device provided by the utility model has the following technical effects:

[0017] The seat frame assembly is slidably connected to the slide rail on the base so that the seat frame assembly can slide back and forth along the slide rail, thereby optimizing the smoothness of the operation of the mechanical extension device and improving the stability and comfort of the mechanical extension device when switching postures. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of a mechanical extension device in a sitting position according to an embodiment of the utility model;

[0019] Figure 2 It is another structural schematic diagram of the mechanical extension device in a sitting state according to an embodiment of the utility model;

[0020] Figure 3 It is a structural schematic diagram of the mechanical extension device in the TV posture state according to an embodiment of the utility model;

[0021] Figure 4 It is another structural schematic diagram of the mechanical extension device in the TV posture state according to an embodiment of the utility model;

[0022] Figure 5 It is a structural schematic diagram of the mechanical stretching device in a lying position according to an embodiment of the utility model;

[0023] Figure 6 It is another structural schematic diagram of the mechanical stretching device in a lying state according to an embodiment of the utility model;

[0024] Figure 7 This is a schematic diagram of the structure of the slide rail in a sitting position or a TV position according to an embodiment of the utility model;

[0025] Figure 8 It is a schematic structural diagram of the slide rail in a lying position according to an embodiment of the utility model.

[0026] The meanings of the reference numerals are as follows:

[0027] 1. Base; 2. Slide rail; 21. Rising section; 22. Straight section; 23. Limiting column; 3. Seat frame assembly; 31. Seat frame mounting frame; 32. Linkage bracket; 33. Linkage slider; 4. Backrest assembly; 41. Backrest mounting frame; 42. First backrest connecting rod; 43. Second backrest connecting rod; 44. Third backrest connecting rod; 45. Fourth backrest connecting rod; 46. Fifth backrest connecting rod; 47. Back pad mounting frame; 5. Leg assembly; 51. Leg mounting frame; 52. First leg connecting rod; 53. Second leg connecting rod; 54. Third leg connecting rod; 55. Fourth leg connecting rod; 56. Fifth leg connecting rod; 57. First foot pad mounting frame; 58. Second foot pad mounting frame; 6. Drive assembly; 61. First transmission connecting rod; 62. Second transmission connecting rod; 63. Third transmission connecting rod. DETAILED DESCRIPTION

[0028] For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0029] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0031] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 The utility model discloses a mechanical stretching device, which is applied to a seat. Preferably, the posture adjustment of the main frame of the mechanical stretching device corresponds to the posture adjustment of the seat, and optionally, the posture of the mechanical stretching device includes a sitting posture, a TV posture and a lying posture.

[0032] See also Figure 1 , Figure 2, Figure 3 , Figure 4 , Figure 5 and Figure 6 In some embodiments, the mechanical extension device includes a base 1, a seat frame assembly 3, a backrest assembly 4, a leg assembly 5 and a drive assembly 6. Preferably, the base 1 is equipped with a slide rail 2; the seat frame assembly 3 is slidably connected to the slide rail 2 and can slide forward and backward along the slide rail 2; the backrest assembly 4 is arranged at the rear end of the seat frame assembly 3, and when the seat frame assembly 3 slides, the backrest assembly 4 can rotate; the leg assembly 5 is arranged at the front end of the seat frame assembly 3; the drive assembly 6 is hinged to the leg assembly 5, and can drive the leg assembly 5 to retract or drive the seat frame assembly 3 to slide forward and backward along the slide rail 2. Preferably, the seat frame assembly 3 is slidably connected to the slide rail 2 on the base 1, so that the seat frame assembly 3 can slide forward and backward along the slide rail 2, optimize the smoothness of the operation of the mechanical extension device, and thus improve the stability and comfort of the mechanical extension device when switching postures.

[0033] See also Figure 1 , Figure 3 and Figure 5 In some embodiments, the driving assembly 6 can drive the leg assembly 5 to retract and retract independently so that the leg assembly 5 extends forward or retracts backward. When the driving assembly 6 drives the leg assembly 5 to extend forward, the mechanical extension device switches from the sitting position to the TV position. Furthermore, after the leg assembly 5 extends forward, the driving assembly 6 can drive the leg assembly 5 to move forward, thereby driving the seat frame assembly 3 to slide forward along the slide rail 2, and then pulling the backrest assembly 4 to rotate, thereby realizing the switching of the mechanical extension device from the TV position to the lying position.

[0034] See also Figure 1 , Figure 2 , Figure 3 and Figure 4In some embodiments, the leg assembly 5 includes a leg mounting frame 51, a first leg connecting rod 52, a second leg connecting rod 53, a third leg connecting rod 54, a fourth leg connecting rod 55, a fifth leg connecting rod 56, a first foot pad mounting frame 57 and a second foot pad mounting frame 58, the leg mounting frame 51 is assembled at the front end of the seat frame assembly 3, the driving assembly 6 is hinged to the first leg connecting rod 52, the first leg connecting rod 52 is hinged between the front end of the leg mounting frame 51 and the second leg connecting rod 53, the first The foot pad mounting frame 57 is hinged to one end of the second leg link 53 away from the first leg link 52, the third leg link 54 is hinged between the first foot pad mounting frame 57 and the second foot pad mounting frame 58, the fourth leg link 55 is hinged between the second foot pad mounting frame 58 and the fifth leg link 56, the fourth leg link 55 is hinged to the first leg link 52, and one end of the fifth leg link 56 away from the fourth leg link 55 is hinged to the rear end of the leg mounting frame 51. Specifically, when the driving assembly 6 drives the leg assembly 5 to extend forward, the driving assembly 6 drives the first leg link 52 to rotate forward around the hinge point between itself and the leg mounting frame 51, and the second leg link 53, driven by the first leg link 52, drives the first foot pad mounting frame 57 to rotate forward. At the same time, the fourth leg link 55, driven by the first leg link 52, drives the fifth leg link 56 and the second foot pad mounting frame 58 to rotate forward, so that the mechanical extension device switches from the sitting state to the TV state, driving the leg assembly 5 to provide support to the legs of the user sitting on the seat, so that the user can maintain a more comfortable and casual sitting posture.

[0035] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6In some embodiments, the backrest assembly 4 includes a backrest mounting frame 41, a first backrest link 42, a second backrest link 43, a third backrest link 44, a fourth backrest link 45, a fifth backrest link 46 and a back cushion mounting frame 47, the backrest mounting frame 41 is assembled at the rear end of the seat frame assembly 3, the first backrest link 42 is hinged to the front end of the backrest mounting frame 41 and the front end of the back cushion mounting frame 47, the second backrest link 43 is hinged between the first backrest link 42 and the third backrest link 44, the fourth backrest link 45 is hinged between the back cushion mounting frame 47 and the third backrest link 44, the rear end of the back cushion mounting frame 47 is hinged to the third backrest link 44, and the third backrest link 44 is hinged to the rear end of the base 1 through the fifth backrest link 46. Specifically, when the leg assembly 5 is extended forward, the driving assembly 6 can drive the leg assembly 5 to move forward, thereby driving the seat frame assembly 3 to slide forward along the slide rail 2, and then pulling the backrest assembly 4 to rotate. Optionally, the backrest mounting frame 41 follows the seat frame assembly 3 to slide forward along the slide rail 2, and drives the first backrest link 42 to move forward, so that the first backrest link 42 drives the front section of the backrest mounting frame 41 to flip upward, and the rear end of the back cushion mounting frame 47 pulls the fourth backrest link 45 to flip downward, so that the back cushion mounted on the back cushion mounting frame 47 lies down to a certain angle, thereby improving the comfort of the seat experience, and realizing the switching of the mechanical extension device from the TV posture state to the lying posture state, so that the user can remain lying on the seat, and at the same time, the second backrest link 43 is pulled forward by the first backrest link 42 to move forward, so that the third backrest link 44 is pulled forward by the backrest mounting frame 41 and the second backrest link 43 to move forward, thereby driving the fifth backrest link 46 to rotate forward around the hinge point between itself and the base 1, and then driving the back cushion mounting frame 47 to move forward while rotating, to achieve zero wall contact, effectively solving the problem that the backrest will touch the wall adjacent to it when the seat switches states, and further optimizing the user experience.

[0036] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6In some embodiments, the seat frame assembly 3 includes a seat frame mounting frame 31 and a linkage bracket 32, the linkage bracket 32 ​​is slidably connected to the slide rail 2, the seat frame mounting frame 31 is assembled on the linkage bracket 32, the leg assembly 5 is hinged to the front end of the seat frame mounting frame 31, and the backrest assembly 4 is assembled to the rear end of the seat frame mounting frame 31. Optionally, the seat frame mounting frame 31 can be assembled on the linkage bracket 32 ​​by one or more of bolt connection, welding, etc., so that when the driving assembly 6 pulls the seat frame mounting frame 31 to move forward and backward through the leg assembly 5, the linkage bracket 32 ​​can slide forward and backward along the slide rail 2, optimize the smoothness of the operation of the mechanical extension device, and thus improve the stability and comfort of the mechanical extension device when switching postures.

[0037] See also Figure 7 and Figure 8 In some embodiments, a plurality of linkage sliders 33 are further included, wherein the linkage sliders 33 are pivotally connected to the linkage bracket 32, and the linkage sliders 33 are slidably connected to the slide rail 2. Optionally, the linkage sliders 33 are provided at the front and rear ends of the linkage bracket 32, so that the linkage bracket 32 ​​is slidably connected to the slide rail 2 through the linkage sliders 33, so as to avoid direct contact between the linkage bracket 32 ​​and the slide rail 2, effectively reduce the contact area between the linkage bracket 32 ​​and the slide rail 2, reduce the friction force when the linkage bracket 32 ​​moves forward and backward, and further optimize the smoothness, stability and comfort of the operation of the mechanical stretching device.

[0038] See also Figure 7 and Figure 8 In some embodiments, the slide rail 2 includes a rising section 21 and a straight section 22 arranged in sequence along the front-to-back direction, the rising section 21 is tilted upward in a direction away from the straight section 22, the front end of the seat frame assembly 3 is slidably connected to the rising section 21, and the rear end of the seat frame assembly 3 is slidably connected to the straight section 22. When the leg assembly 5 is extended forward, the driving assembly 6 can drive the leg assembly 5 to move forward, thereby driving the seat frame assembly 3 to slide forward along the slide rail 2. Specifically, the front end of the seat frame assembly 3 slides obliquely upward along the rising section 21, and the rear end of the seat frame assembly 3 slides straightly along the straight section 22, so that the seat frame assembly 3 and the leg assembly 5 are obliquely lifted, thereby realizing an oblique lifting of the seat, achieving a zero gravity effect, and increasing the user's experience.

[0039] See also Figure 7 and Figure 8In some embodiments, at least one limiting column 23 is further included, and the limiting column 23 is arranged between the rising section 21 and the straight section 22. Preferably, when the seat frame assembly 3 moves forward along the slide rail 2, the linkage bracket 32 ​​drives the linkage slider 33 to move forward along the rising section 21 or the straight section 22. When the seat frame assembly 3 moves forward to the first predetermined position, the linkage slider 33 at the rear end of the linkage bracket 32 ​​abuts against the limiting column 23, thereby preventing the linkage slider 33 from disengaging from the slide rail 2 forward, that is, limiting the limit position of the forward movement of the seat frame assembly 3. Similarly, when the seat frame assembly 3 moves backward to the second predetermined position, the linkage slider 33 at the front end of the linkage bracket 32 ​​abuts against the limiting column 23, thereby preventing the linkage slider 33 from disengaging from the slide rail 2 backward, that is, limiting the limit position of the backward movement of the seat frame assembly 3. The limit positions of the backward and forward movements of the seat frame assembly 3 are limited by the limiting column 23, thereby fully optimizing the structure of the mechanical stretching device. Optionally, only one limiting column 23 may be provided between the rising section 21 and the straight section 22. When the seat frame assembly 3 moves forward to the first predetermined position, the linkage slider 33 at the rear end of the linkage bracket 32 ​​abuts against the limiting column 23. When the seat frame assembly 3 moves backward to the second predetermined position, the linkage slider 33 at the front end of the linkage bracket 32 ​​abuts against the limiting column 23. Optionally, there are two limiting columns 23. The first limiting column 23 is provided at one end of the rising section 21 close to the straight section 22, and the second limiting column 23 is provided at one end of the straight section 22 close to the rising section 21. When the seat frame assembly 3 moves forward to the first predetermined position, the linkage slider 33 at the rear end of the linkage bracket 32 ​​abuts against the second limiting column 23. When the seat frame assembly 3 moves backward to the second predetermined position, the linkage slider 33 at the front end of the linkage bracket 32 ​​abuts against the first limiting column 23.

[0040] See also Figure 2 , Figure 4 and Figure 6In some embodiments, the driving assembly 6 includes a driving unit, a first transmission link 61 and a second transmission link 62. The driving unit is assembled on the base 1. The first transmission link 61 is hinged between the driving unit and the second transmission link 62. The second transmission link 62 is fixedly connected to the leg assembly 5. Optionally, the driving unit can be a driving motor, a cylinder, an electric cylinder, an electric lead screw, etc. Preferably, the output shaft of the driving unit is hinged to one end of the first transmission link 61, and the other end of the first transmission link 61 is hinged to the second transmission link 62 fixedly connected to the leg assembly 5, so that the driving unit can drive the leg assembly 5 to extend and retract or drive the seat frame assembly 3 to slide forward and backward along the slide rail 2 through the first transmission link 61 and the second transmission link 62.

[0041] See also Figure 2 , Figure 4 and Figure 6 In some embodiments, the driving unit includes a slider motor, and the slider motor is equipped with a third transmission link 63, and the third transmission link 63 is hinged to the first transmission link 61. Optionally, the slider motor is extended along the front-to-back direction. Specifically, the driving slider in the slider motor is hinged to the first transmission link 61 through the third transmission link 63. When the driving slider in the slider motor moves along the front-to-back direction, the third transmission link 63 drives the second transmission link 62 through the first transmission link 61, thereby driving the leg assembly 5 to extend and retract or driving the seat frame assembly 3 to slide forward and backward along the slide rail 2.

[0042] In some embodiments, a chair includes the mechanical extension device as described above.

[0043] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8In some embodiments, in order to further provide seat stability, the mechanical extension device is provided on both sides of the left and right sides of the seat, and the two mechanical extension devices are symmetrically arranged. Optionally, the base 1 is arranged in a frame. Optionally, the base 1 is surrounded by two slide rails 2 arranged on the left and right sides of the base 1 and two square tubes arranged at the front and rear ends of the base 1. Further, a pillar is connected to the lower end of the base 1 to adjust the height of the seat; Optionally, the front and rear ends of the base 1 are provided with assembly beams, and the slider motor is assembled on the two assembly beams; Optionally, a first beam can be connected between the front and rear ends of the two seat frame mounting frames 31 to drive the two seat frame assemblies 3 to move synchronously to improve the mechanical extension. To ensure the stability of the extension device, further, the seat frame mounting frame 31 and the crossbeam may be provided with hooks to facilitate the assembly of the seat cushion; optionally, a second crossbeam may be connected between the two leg assemblies 5, specifically, a sixth leg link is fixedly connected to the end of the second crossbeam, the sixth leg link is hinged to the fourth leg link 55, and a seventh leg link is hinged between the sixth leg link and the second leg link 53, so that the two leg assemblies 5 can be driven by the driving assembly 6 to synchronously extend forward or retract backward, further, the second transmission link 62 is fixedly connected to the first leg link 52 of the two leg assemblies 5, so that the slider motor can be synchronously driven to transmit power to the two leg assemblies 5. Preferably, when the mechanical extension device switches from a sitting position to a TV position, the slider motor drives the first transmission link 61 to move forward through the third transmission link 63, driving the first transmission link 61 to drive the leg assembly 5 to extend forward through the second transmission link 62; when the mechanical extension device switches from a TV position to a lying position, the drive assembly 6 drives the leg assembly 5 to move forward, thereby driving the seat frame assembly 3 to pull the backrest assembly 4 along the slide rail 2 to rotate.Specifically, the backrest mounting frame 41 follows the seat frame assembly 3 to slide forward along the slide rail 2, and drives the first backrest connecting rod 42 to move forward, so that the first backrest connecting rod 42 drives the front section of the backrest mounting frame 41 to flip upward, and the rear end of the back cushion mounting frame 47 pulls the fourth backrest connecting rod 45 to flip downward, so that the back cushion mounted on the back cushion mounting frame 47 lies down to a certain angle, thereby improving the comfort of the seat experience. At the same time, the second backrest connecting rod 43 is pulled forward by the first backrest connecting rod 42, so that the third backrest connecting rod 44 is pulled forward by the backrest mounting frame 41 and the second backrest connecting rod 43, thereby driving the fifth backrest connecting rod 46 to rotate around itself and the base 1 The hinge point rotates forward, thereby driving the back cushion mounting frame 47 to move forward while rotating, achieving zero leaning against the wall, and when the seat frame assembly 3 moves forward along the slide rail 2, the front end of the linkage bracket 32 ​​slides obliquely upward along the rising section 21, and the rear end of the linkage bracket 32 ​​slides straightly along the straight section 22, so that the seat frame assembly 3 and the leg assembly 5 are obliquely lifted, thereby achieving an oblique lifting of the seat, achieving a zero gravity effect, and increasing the user's experience. At the same time, the slide rail 2 can also be used to optimize the smoothness of the forward and backward sliding of the linkage bracket 32, thereby optimizing the smoothness of the operation of the mechanical extension device, and thereby improving the stability and comfort of the mechanical extension device when switching postures.

[0044] The technical means disclosed in the solution of the utility model are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical solutions composed of any combination of the above technical features. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model, and these improvements and modifications are also regarded as the protection scope of the utility model.

Claims

1. A mechanical stretching device, characterized in that: include: A base (1), wherein a slide rail (2) is mounted on the base (1); A seat frame assembly (3), wherein the seat frame assembly (3) is slidably connected to the slide rail (2) and is capable of sliding forward and backward along the slide rail (2); A backrest assembly (4), wherein the backrest assembly (4) is arranged at the rear end of the seat frame assembly (3), and when the seat frame assembly (3) slides, the backrest assembly (4) can rotate; A leg assembly (5), wherein the leg assembly (5) is arranged at the front end of the seat frame assembly (3); A driving assembly (6) is hinged to the leg assembly (5) and can drive the leg assembly (5) to extend and retract or drive the seat frame assembly (3) to slide forward and backward along the slide rail (2).

2. The mechanical stretching device according to claim 1, characterized in that: The leg assembly (5) comprises a leg mounting frame (51), a first leg connecting rod (52), a second leg connecting rod (53), a third leg connecting rod (54), a fourth leg connecting rod (55), a fifth leg connecting rod (56), a first foot pad mounting frame (57) and a second foot pad mounting frame (58); the leg mounting frame (51) is mounted on the front end of the seat frame assembly (3); the driving assembly (6) is hinged to the first leg connecting rod (52); the first leg connecting rod (52) is hinged between the front end of the leg mounting frame (51) and the second leg connecting rod (53); the first foot pad The mounting frame (57) is hinged to one end of the second leg link (53) away from the first leg link (52); the third leg link (54) is hinged between the first foot pad mounting frame (57) and the second foot pad mounting frame (58); the fourth leg link (55) is hinged between the second foot pad mounting frame (58) and the fifth leg link (56); the fourth leg link (55) is hinged to the first leg link (52); and one end of the fifth leg link (56) away from the fourth leg link (55) is hinged to the rear end of the leg mounting frame (51).

3. The mechanical stretching device according to claim 1, characterized in that: The backrest assembly (4) comprises a backrest mounting frame (41), a first backrest connecting rod (42), a second backrest connecting rod (43), a third backrest connecting rod (44), a fourth backrest connecting rod (45), a fifth backrest connecting rod (46) and a back cushion mounting frame (47); the backrest mounting frame (41) is mounted on the rear end of the seat frame assembly (3); the first backrest connecting rod (42) is hinged to the front end of the backrest mounting frame (41) and the front end of the back cushion mounting frame (47). The second backrest link (43) is hinged between the first backrest link (42) and the third backrest link (44), the fourth backrest link (45) is hinged between the back cushion mounting frame (47) and the third backrest link (44), the rear end of the back cushion mounting frame (47) is hinged to the third backrest link (44), and the third backrest link (44) is hinged to the rear end of the base (1) through the fifth backrest link (46).

4. The mechanical stretching device according to claim 1, characterized in that: The seat frame assembly (3) comprises a seat frame mounting frame (31) and a linkage bracket (32), wherein the linkage bracket (32) is slidably connected to the slide rail (2), the seat frame mounting frame (31) is assembled on the linkage bracket (32), the leg assembly (5) is hinged to the front end of the seat frame mounting frame (31), and the backrest assembly (4) is assembled on the rear end of the seat frame mounting frame (31).

5. The mechanical stretching device according to claim 4, characterized in that: It also comprises a plurality of linkage slide blocks (33), wherein the linkage slide blocks (33) are pivotally connected to the linkage bracket (32), and the linkage slide blocks (33) are slidably connected to the slide rail (2).

6. The mechanical stretching device according to claim 1, characterized in that: The slide rail (2) comprises an ascending section (21) and a straight section (22) arranged in sequence along the front-to-back direction; the ascending section (21) is arranged to be inclined upward in a direction away from the straight section (22); the front end of the seat frame assembly (3) is slidably connected to the ascending section (21), and the rear end of the seat frame assembly (3) is slidably connected to the straight section (22).

7. The mechanical stretching device according to claim 6, characterized in that: It also comprises at least one limiting column (23), wherein the limiting column (23) is arranged between the rising section (21) and the straight section (22).

8. The mechanical stretching device according to claim 1, characterized in that: The driving assembly (6) comprises a driving unit, a first transmission link (61) and a second transmission link (62); the driving unit is assembled on the base (1); the first transmission link (61) is hinged between the driving unit and the second transmission link (62); and the second transmission link (62) is fixedly connected to the leg assembly (5).

9. The mechanical stretching device according to claim 8, characterized in that: The driving unit comprises a slider motor, on which a third transmission connecting rod (63) is mounted, and the third transmission connecting rod (63) is hinged to the first transmission connecting rod (61).

10. A seat, characterized in that: Comprising a mechanical stretching device as described in any one of claims 1-9.

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