CN221179892U - Chair seat - Google Patents

Abstract

The utility model discloses a seat, which belongs to the technical field of seats, and comprises a first backrest, a second backrest and an adjusting mechanism, wherein the second backrest is arranged at a first end of the first backrest; the adapter has a first moving position and a second moving position, wherein in the first moving position, the second backrest is close to the second end of the first backrest; in the second moved position, the second backrest is distal from the second end of the first backrest; when the lumbar support device is used, the second backrest is required to support lumbar, the adapter is moved to the second movement position, and the second backrest is required to support lumbar, and the adapter is moved to the first movement position; the seat backrest is quickly adjusted, and the position for supporting lumbar is adjusted; when adjusting, only need stir the adaptor and just can realize adjusting, easy operation.

Description

Chair seat

Technical Field

The utility model belongs to the technical field of seats, and particularly relates to a seat.

Background

Typically, a seat includes a seat cushion and a backrest. In particular, the backrest is a part supporting the user from the waist to the back, the shoulder and the cervical vertebrae, so that it can be manufactured ergonomically in various forms. The backrest is usually made by putting a sheet material into a frame and wrapping a layer of cloth or leather on the surface.

In order to give a comfortable use feeling to the user, it is necessary to provide a backrest for adjusting the front-rear concave-convex direction of the user's waist and capable of adjusting the height of the lumbar support, improving the user's comfort. Although, chinese patent No.: 20110183874. X discloses a seat back in which the degree of protrusion of the cushion frame is adjusted by rotating a worm screw and a worm wheel by a rotational motion applied to a lever, thereby adjusting the position of supporting lumbar vertebrae. However, the adjusting mode of the adjusting mechanism needs to be realized by rotary motion, the operation is more complicated, and the adopted parts are more and the manufacturing cost is relatively high.

Disclosure of utility model

The utility model aims to provide a seat, which realizes rapid adjustment of a seat back and adjustment of the position for supporting lumbar, and is simple to operate; the use of parts is reduced, and the production cost is reduced.

The technical scheme is as follows:

A seat comprising a first backrest, a second backrest and an adjusting mechanism, wherein the second backrest is arranged at a first end of the first backrest, the adjusting mechanism is provided with an adapter, the first end of the adapter is hinged with the second backrest, and the second end of the adapter is in running fit with the second end of the first backrest;

The adapter has a first moved position in which the second backrest is proximate the second end of the first backrest and a second moved position; in a second moved position, the second backrest is distal from the second end of the first backrest.

In one embodiment, an adjustment angle is formed between the second backrest and the horizontal line; the adapter is arranged at a first moving position, the angle of the adjusting angle is smaller than or equal to 90 degrees, and the adapter is arranged at a second moving position, and the angle of the adjusting angle is larger than or equal to 90 degrees.

In one embodiment, the seat has a base with a bottom fixed to the first backrest, a top pivotally connected to the adapter, and a handle mounted to an outer wall of the adapter.

In one embodiment, the adaptor is provided with a first pivot plate, a first rotating shaft, a first limiting hole and a second pivot plate, the bottom of the second backrest is in running fit with the first rotating shaft, the first end of the first rotating shaft is mounted on the second pivot plate, and the second end of the first rotating shaft is matched with the first limiting hole;

The base is provided with a second rotating shaft and a second limiting hole, a first end of the second rotating shaft is mounted on the first pivot plate, a second end of the second rotating shaft penetrates through the second limiting hole and is fixed with the second pivot plate, and the second rotating shaft is in rotating fit with the second limiting hole.

In one embodiment, the first pivoting plate has a limiting block, and the second pivoting plate has a limiting groove matched with the limiting block.

In one embodiment, the handle is in a columnar structure, and the handle and the second rotating shaft are arranged on the same axis.

In one embodiment, the adaptor further comprises a pulling piece, the pulling piece is mounted on the handle, and the length direction of the pulling piece is intersected with the axial line direction of the handle.

In one embodiment, the second backrest comprises a first leaning part, a second leaning part, a third leaning part, a fourth leaning part and a supporting pad, wherein the first leaning part, the second leaning part, the third leaning part and the fourth leaning part are connected end to end in sequence, the third leaning part is arranged on the first backrest, and two ends of the supporting pad are respectively arranged on the second leaning part and the fourth leaning part;

The second leaning part and the fourth leaning part are arc-shaped, and the extrados of the second leaning part and the fourth leaning part faces the first backrest.

In one embodiment, the first backrest includes a first support portion, a second support portion, a third support portion, a fourth support portion, and a fifth support portion, where the first support portion, the second support portion, the third support portion, the fourth support portion, and the fifth support portion are connected;

A first supporting point is formed between the first leaning part and the second leaning part, a second supporting point is formed between the first supporting part and the second supporting part, and the second supporting point is abutted with the first supporting point; a third supporting point is formed between the first leaning part and the fourth leaning part, a fourth supporting point is formed between the fourth supporting part and the fifth supporting part, and the fourth supporting point is abutted with the third supporting point.

The technical scheme provided by the utility model has the following advantages and effects:

1. The first end of the adapter is hinged with the second backrest, and the second end of the adapter is in running fit with the second end of the first backrest; the first end of the adapter rotates around the second end of the adapter, and in the first moving position, the bottom of the second backrest is close to the first backrest, and the distance between the waist of the user and the second backrest is larger, so that the waist of the user is far away from the lumbar vertebra of the user; in the second moving position, the bottom of the second backrest is away from the first backrest, and the distance between the waist of the user and the second backrest is smaller, thereby approaching the lumbar of the user. When the lumbar support device is used, the second backrest is required to support lumbar, the adapter is moved to the second movement position, and the second backrest is required to support lumbar, and the adapter is moved to the first movement position; the backrest of the seat can be quickly adjusted, and the position for supporting lumbar vertebra can be adjusted; when in adjustment, the adjustment can be realized only by stirring the adapter, and the operation is simple; moreover, the worm and gear are not needed to be matched, the use of parts is reduced, and the production cost is reduced.

2. Because the adjusting angle is formed between the second backrest and the horizontal line and is used for changing the sitting posture of a user, when the adapter is in the first moving position and the angle of the adjusting angle is smaller than or equal to 90 degrees, the whole of the second backrest is forwards close to the user, the sitting posture of the user tends to be in a vertical state, and the bottom of the second backrest is backwards supported by the lumbar vertebra of the user; when the adapter is in the second moving position, the angle of the adjusting angle is larger than or equal to 90 degrees, the whole of the second backrest is far away from the user backwards, the sitting posture of the user tends to be in a supine state, the bottom of the second backrest supports lumbar vertebrae of the user forwards, and the position for supporting lumbar vertebrae is further adjusted.

3. The base is used for supporting the adapter, the handle is pivoted with the adapter, the handle is arranged on the outer wall of the adapter, the first end of the adapter is provided with a moving path rotating around the second end of the adapter, the first end of the adapter is stirred through acting fingers on the outer wall of the handle, the adapter and the handle form a lever structure, acting force of the adapter is saved, the position of the adapter can be adjusted by stirring the first end of the adapter, and convenience in operation is improved.

4. The first pivot is used for being fixed with first pivot board and second pivot board, and the adaptor is through the bottom pin joint of first pivot and second back, still utilizes first pivot simultaneously, improves the wholeness of adaptor, and is fixed with first pivot board and second pivot board respectively through first pivot, avoids first pivot and second back to break away from, improves adaptor and second back pivoted stability. The base is used for supporting the adapter, the first pivot plate and the second pivot plate are in rotary fit with the base through the second rotating shaft, the adapter is pivoted with the base, and the stability of rotary fit of the adapter and the first backrest is improved.

5. Through stopper and spacing groove cooperation, improve the stability after first pin joint board and the second pin joint board are connected, and improve the wholeness of adaptor.

6. This handle is columnar structure, and the arc outer wall of handle increases the area of contact with the hand that the finger of being convenient for offsets with the outer wall of handle, improves the comfort level that acts on the handle, and the handle sets up with the coaxial heart line of second pivot, makes the first end effort that acts on the adaptor directly act on the second pivot, and the first end of the adaptor of being convenient for is rotatory around the second end of adaptor, saves the effort of applying to the adaptor, further improves the convenience of operation.

7. The plectrum is installed on the handle, and the length direction of plectrum is crossing with the axial lead direction of handle, and the plectrum forms pole thick stick structure with the handle, and the plectrum has the rotatory travel path of around handle or second pivot, stirs this plectrum with the hand to drive the handle rotation, thereby make the first end of adaptor rotate around the second end of adaptor, realize adjusting the position of adaptor, further improve the convenience of operation.

8. The supporting pad is used for supporting the back or waist of a user, the pressure born by the supporting pad is transmitted to the first leaning part, the second leaning part, the third leaning part and the fourth leaning part, then the pressure is transmitted to the first backrest through the third leaning part, the second backrest forms a stable supporting structure, the second leaning part and the fourth leaning part are arc-shaped, the extrados of the second leaning part and the fourth leaning part faces the first backrest, the intrados of the second leaning part and the fourth leaning part faces the user, the fitting degree of the second backrest and the back of the user is improved, the contact area of the second backrest and the user is increased, the supporting performance of the second backrest is improved, and the comfort of the user is improved.

9. The first supporting part, the second supporting part, the third supporting part, the fourth supporting part and the fifth supporting part are used for forming a first backrest with high stability, the second supporting point of the first backrest is abutted with the first supporting point of the second backrest, the first backrest is enabled to support the second backrest on one side, the fourth supporting point of the first backrest is enabled to be abutted with the third supporting point of the second backrest, the second backrest is enabled to be supported on the other side, and the integrity of the first backrest and the second backrest is improved, so that the supporting stability of the seat is improved.

10. The adapter is pivoted with the second backrest through the first rotating shaft, and the adapter is pivoted with the first backrest through the second rotating shaft, so that the stability of the adapter in rotating fit with the first backrest and the second backrest respectively is improved, and the adapter is provided with a position for adjusting and supporting lumbar vertebrae.

Drawings

FIG. 1 is a schematic view of a seat in an embodiment of the utility model.

Fig. 2 is a schematic partial view of a seat according to an embodiment of the present utility model.

Fig. 3 is a schematic partial view of a seat according to an embodiment of the utility model.

Fig. 4 is a partial exploded view of a seat in an embodiment of the present utility model.

Fig. 5 is an enlarged view at a of fig. 2 in an embodiment of the present utility model.

Fig. 6 is an exploded view of an adjustment mechanism in an embodiment of the utility model.

Fig. 7 is a schematic diagram of an adjustment mechanism in an embodiment of the utility model.

Reference numerals illustrate:

100. A seat; 1. a first backrest; 11. a first support portion; 111. a mounting groove; 12. a second supporting part; 13. a third supporting part; 14. a fourth supporting part; 15. a fifth supporting part; 2. a second backrest; 21. a first resting portion; 22. a second resting portion; 23. a third resting portion; 24. a fourth resting portion; 25. a first rotating shaft; 26. a support pad; 3. an adjusting mechanism; 31. an adapter; 311. a first pivot plate; 312. a second pivot plate; 313. a first limiting hole; 314. a limiting block; 32. a handle; 33. a pulling piece; 34. a base; 341. a second limiting hole; 342. a second rotating shaft; 10. a first movement position; 20. a second movement position; 30. a first support point; 40. a second support point; 50. a third supporting point; 60. a fourth supporting point; 70. adjusting the angle; 101. a cushion; 102. and a moving mechanism.

Detailed Description

In order that the utility model may be readily understood, a more particular description of specific embodiments thereof will be rendered by reference to specific embodiments that are illustrated in the appended drawings.

The terms "first" and "second" … "as used herein, unless specifically indicated or otherwise defined, are merely used to distinguish between names and do not denote a particular quantity or order.

The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items, unless specifically stated or otherwise defined.

The term "fixed" or "connected" as used herein may be directly fixed or connected to an element, or indirectly fixed or connected to an element.

As shown in fig. 1 to 7, a seat 100 includes a first backrest 1, a second backrest 2, and an adjusting mechanism 3, the second backrest 2 is mounted on a first end of the first backrest 1, the adjusting mechanism 3 has an adapter 31, the first end of the adapter 31 is hinged with the second backrest 2, and a second end of the adapter 31 is in rotational fit with a second end of the first backrest 1; the adapter 31 has a first mobile position 10 and a second mobile position 20, in which first mobile position 10 the second backrest 2 is close to the second end of the first backrest 1; in the second displaced position 20, the second backrest 2 is remote from the second end of the first backrest 1. The first end of the adapter piece 31 is hinged with the second backrest 2, and the second end of the adapter piece 31 is in running fit with the second end of the first backrest 1; the adapter 31 is provided with two moving positions in the circumferential direction, namely a first moving position 10 and a second moving position 20, the first end of the adapter 31 rotates around the second end of the adapter 31, and in the first moving position 10, the bottom of the second backrest 2 is close to the first backrest 1, and the distance between the waist of a user and the second backrest 2 is larger, so that the waist of the user is far away from the lumbar vertebra of the user; in the second movement position 20, the bottom of the second backrest 2 is distant from the first backrest 1, and the distance between the waist of the user and the second backrest 2 is small, so as to be close to the lumbar of the user. When in use, the second backrest 2 is required to support lumbar, the adapter 31 is moved to the second moving position 20, and the second backrest 2 is required to support lumbar, the adapter 31 is moved to the first moving position 10; the backrest of the seat 100 can be quickly adjusted, and the position of supporting lumbar can be adjusted to be more fit with the contour of the waist of a user; during adjustment, the adjustment can be realized only by stirring the adapter 31, and the operation is simple; moreover, the worm and gear are not needed to be matched, the use of parts is reduced, and the production cost is reduced.

In the present embodiment, the first end of the adapter 31 is the top of the adapter 31 (the bottom of the second backrest 2), and the second end of the adapter 31 is the bottom of the adapter 31 (the bottom of the first backrest 1).

In this embodiment, the seat 100 further includes a seat cushion 101 and a moving mechanism 102, the bottom of the first backrest 1 is mounted on the seat cushion 101, the seat cushion 101 is mounted on the moving mechanism 102, and the bottom of the moving mechanism 102 has a plurality of universal wheels for moving the seat 100.

As shown in fig. 3 and 7, an adjustment angle 70 is formed between the second backrest 2 and the horizontal line; the angle of the adjustment angle 70 is less than or equal to 90 degrees when the adapter 31 is in the first movement position 10, and the angle of the adjustment angle 70 is greater than or equal to 90 degrees when the adapter 31 is in the second movement position 20. Since the second backrest 2 and the horizontal line form the adjusting angle 70, the adjusting angle 70 is used for changing the sitting posture of the user, when the adapter 31 is at the first moving position 10 and the angle of the adjusting angle 70 is less than or equal to 90 degrees, the whole of the second backrest 2 is close to the user forwards, the sitting posture of the user tends to be vertical, and the bottom of the second backrest 2 supports the lumbar vertebra of the user backwards; when the adapter 31 is in the second moving position 20, the angle of the adjusting angle 70 is greater than or equal to 90 degrees, the whole of the second backrest 2 is far away from the user, the sitting posture of the user is prone to the supine state, the bottom of the second backrest 2 is supported by the front of the lumbar of the user, and the position for supporting the lumbar is further adjusted.

As shown in fig. 4 to 6, the seat 100 has a base 34 and a handle 32, the bottom of the base 34 is fixed on the first backrest 1, the top of the base 34 is pivoted with the adapter 31, and the handle 32 is mounted on the outer wall of the adapter 31. The adaptor 31 is supported by the base 34 and is pivoted with the adaptor 31, the handle 32 is arranged on the outer wall of the adaptor 31, the first end of the adaptor 31 is provided with a moving path rotating around the second end of the adaptor 31, the first end of the adaptor 31 is stirred by acting a finger on the outer wall of the handle 32, the adaptor 31 and the handle 32 form a lever structure, the acting force applied to the adaptor 31 is saved, the position of the adaptor 31 can be adjusted by stirring the first end of the adaptor 31, and the convenience of operation is improved.

As shown in fig. 4 to 6, the adaptor 31 has a first pivot plate 311, a first pivot shaft 25, a first limiting hole 313 and a second pivot plate 312, the bottom of the second backrest 2 is in rotation fit with the first pivot shaft 25, a first end of the first pivot shaft 25 is mounted on the second pivot plate 312, and a second end of the first pivot shaft 25 is matched with the first limiting hole 313; the first rotating shaft 25 is used for being fixed with the first pivot plate 311 and the second pivot plate 312, the adaptor 31 is pivoted with the bottom of the second backrest 2 through the first rotating shaft 25, meanwhile, the integrity of the adaptor 31 is improved by using the first rotating shaft 25, the adaptor 31 is respectively fixed with the first pivot plate 311 and the second pivot plate 312 through the first rotating shaft 25, the first rotating shaft 25 is prevented from being separated from the second backrest 2, and the rotation stability of the adaptor 31 and the second backrest 2 is improved.

In addition, the base 34 has a second rotating shaft 342 and a second limiting hole 341, a first end of the second rotating shaft 342 is mounted on the first pivot plate 311, and a second end of the second rotating shaft 342 passes through the second limiting hole 341 and is fixed with the second pivot plate 312, and the second rotating shaft 342 is in a rotating fit with the second limiting hole 341. The base 34 is used for supporting the adaptor 31, and the first pivot plate 311 and the second pivot plate 312 are in running fit with the base 34 through the second rotating shaft 342, so that the adaptor 31 is pivoted with the base 34, and the running fit stability of the adaptor 31 and the first backrest 1 is improved.

As shown in fig. 6, the first pivot plate 311 has a stopper 314, and the second pivot plate 312 has a stopper groove (not shown) that cooperates with the stopper 314. Through the cooperation of the limiting block 314 and the limiting groove, the stability of the first pivot plate 311 and the second pivot plate 312 after being connected is improved, and the integrity of the adapter 31 is improved.

As shown in fig. 6, the handle 32 has a columnar structure, so that fingers can conveniently abut against the outer wall of the handle 32, the contact area between the arc-shaped outer wall of the handle 32 and the hand is increased, the comfort level of the handle 32 is improved, the handle 32 and the second rotating shaft 342 are coaxially arranged, the acting force acting on the first end of the adapter 31 directly acts on the second rotating shaft 342, the first end of the adapter 31 can conveniently rotate around the second end of the adapter 31, the acting force applied to the adapter 31 is saved, and the convenience of operation is further improved.

As shown in fig. 4 to 6, the adapter 31 further has a paddle 33, the paddle 33 is mounted on the handle 32, and a longitudinal direction of the paddle 33 intersects with an axial line direction of the handle 32. The pulling piece 33 is mounted on the handle 32, the length direction of the pulling piece 33 is intersected with the axial line direction of the handle 32, the pulling piece 33 and the handle 32 form a lever structure, the pulling piece 33 is provided with a moving path rotating around the handle 32 or the second rotating shaft 342, the pulling piece 33 is pulled by hand, so that the handle 32 is driven to rotate, the first end of the adapter 31 rotates around the second end of the adapter 31, the position of the adapter 31 is adjusted, and the convenience of operation is further improved.

As shown in fig. 2 to 4, the second backrest 2 includes a first resting portion 21, a second resting portion 22, a third resting portion 23, a fourth resting portion 24 and a support pad 26, the first resting portion 21, the second resting portion 22, the third resting portion 23 and the fourth resting portion 24 are connected end to end in sequence, the third resting portion 23 is mounted on the first backrest 1, and both ends of the support pad 26 are respectively mounted on the second resting portion 22 and the fourth resting portion 24; the second resting portion 22 and the fourth resting portion 24 are arc-shaped, and the outer arc surfaces of the second resting portion 22 and the fourth resting portion 24 face the first backrest 1. The support pad 26 is used for supporting the back or waist of a user, the pressure received by the support pad 26 is transferred to the first leaning portion 21, the second leaning portion 22, the third leaning portion 23 and the fourth leaning portion 24, and then the pressure is transferred to the first backrest 1 through the third leaning portion 23, so that the second backrest 2 forms a stable support structure, the second leaning portion 22 and the fourth leaning portion 24 are arc-shaped, the extrados of the second leaning portion 22 and the fourth leaning portion 24 face the first backrest 1, the intrados of the second leaning portion 22 and the fourth leaning portion 24 face the user, the fit degree of the second backrest 2 and the back of the user is improved, the contact area of the second backrest 2 and the user is increased, the support performance of the second backrest 2 is improved, and the comfort of the user is improved.

As shown in fig. 2 to 4, the first backrest 1 includes a first support 11, a second support 12, a third support 13, a fourth support 14, and a fifth support 15, the first support 11 having a mounting groove 111, the mounting groove 111 being used for mounting the base 34 of the adjustment mechanism 3, the first support 11, the second support 12, the third support 13, the fourth support 14, and the fifth support 15 being connected end to end; a first supporting point 30 is formed between the first leaning part 21 and the second leaning part 22, a second supporting point 40 is formed between the first supporting part 11 and the second supporting part 12, and the second supporting point 40 is abutted with the first supporting point 30; a third supporting point 50 is formed between the first leaning portion 21 and the fourth leaning portion 24, a fourth supporting point 60 is formed between the fourth supporting portion 14 and the fifth supporting portion 15, and the fourth supporting point 60 is abutted with the third supporting point 50. The first support portion 11, the second support portion 12, the third support portion 13, the fourth support portion 14, and the fifth support portion 15 are used for forming the first backrest 1 with relatively high stability, the second support point 40 of the first backrest 1 is abutted against the first support point 30 of the second backrest 2, the first backrest 1 is abutted against the second backrest 2 on one side, the fourth support point 60 of the first backrest 1 is abutted against the third support point 50 of the second backrest 2, the first backrest 1 is abutted against the second backrest 2 on the other side, and the integrity of the first backrest 1 and the second backrest 2 is improved, so that the support stability of the seat 100 is improved.

As shown in fig. 6 and 7, the adjustment principle of this seat 100 is: when the seat 100 is installed, the second backrest 2 and the adapter 31 are bent, and the first end of the adapter 31 can rotate around the second end of the adapter 31 in the circumferential direction and is limited by the limitation of the second backrest 2 to the adapter 31; when the adaptor 31 moves from the first moving position 10 to the second moving position 20, the adaptor 31 presses the second backrest 2, so that the second backrest 2 has a reaction force after being pressed; when the first end of the adapter 31 is located between the first moving position 10 and the second moving position 20, that is, the first end of the adapter 31 is located directly above the second end of the adapter 31, the adapter 31 will receive the reaction force of the second backrest 2, so that the adapter 31 is reset to the first moving position 10 or the second moving position 20; therefore, the position of the first end of the adapter 31 directly above the second end of the adapter 31 is not stable, so that the first end of the adapter 31 moves to the first movement position 10 or the second movement position 20. In the first mobile position 10, the bottom of the second backrest 2 is close to the bottom of the first backrest 1 (i.e. away from the lumbar of the user); in the second displaced position 20, the bottom of the second backrest 2 is remote from the bottom of the first backrest 1 (i.e. close to the lumbar of the user).

The above examples are also not an exhaustive list based on the utility model, and there may be a number of other embodiments not listed. Any substitutions and modifications made without departing from the spirit of the utility model are within the scope of the utility model.

Claims (9)

1. The seat is characterized by comprising a first backrest, a second backrest and an adjusting mechanism, wherein the second backrest is arranged at the first end of the first backrest, the adjusting mechanism is provided with an adapter, the first end of the adapter is hinged with the second backrest, and the second end of the adapter is in running fit with the second end of the first backrest;

Wherein the adapter has a first moved position in which the second backrest is proximate the second end of the first backrest and a second moved position; in a second moved position, the second backrest is distal from the second end of the first backrest.

2. The seat of claim 1, wherein the second backrest forms an adjustment angle with the horizontal; the adapter is arranged at a first moving position, the angle of the adjusting angle is smaller than or equal to 90 degrees, and the adapter is arranged at a second moving position, and the angle of the adjusting angle is larger than or equal to 90 degrees.

3. The seat of claim 1, wherein the seat has a base and a handle, the base having a bottom portion secured to the first backrest, the base having a top portion pivotally connected to the adapter, and the handle being mounted to an outer wall of the adapter.

4. A seat as set forth in claim 3 wherein said adapter has a first pivot plate, a first pivot shaft, a first limiting aperture and a second pivot plate, said second backrest bottom being in rotational engagement with said first pivot shaft, a first end of said first pivot shaft being mounted to said second pivot plate, and a second end of said first pivot shaft being in engagement with said first limiting aperture;

The base is provided with a second rotating shaft and a second limiting hole, a first end of the second rotating shaft is mounted on the first pivot plate, a second end of the second rotating shaft penetrates through the second limiting hole and is fixed with the second pivot plate, and the second rotating shaft is in rotating fit with the second limiting hole.

5. The seat of claim 4 wherein the first pivot plate has a stopper and the second pivot plate has a stopper slot that mates with the stopper.

6. The seat of claim 4, wherein the handle is in a cylindrical configuration, the handle being disposed coaxially with the second axis of rotation.

7. The seat of claim 6, wherein the adapter further has a paddle mounted to the handle, and wherein a length direction of the paddle intersects a direction of an axis of the handle.

8. A seat as claimed in any one of claims 1 to 7 wherein the second backrest comprises a first rest, a second rest, a third rest, a fourth rest and a support pad, the first rest, the second rest, the third rest and the fourth rest being connected end to end in sequence, the third rest being mounted on the first backrest, the support pad being mounted on the second rest and the fourth rest at opposite ends thereof;

The second leaning part and the fourth leaning part are arc-shaped, and the extrados of the second leaning part and the fourth leaning part faces the first backrest.

9. The seat of claim 8, wherein the first back includes a first support, a second support, a third support, a fourth support, and a fifth support, the first support, the second support, the third support, the fourth support, and the fifth support being connected at the head and tail;

A first supporting point is formed between the first leaning part and the second leaning part, a second supporting point is formed between the first supporting part and the second supporting part, and the second supporting point is abutted with the first supporting point; a third supporting point is formed between the first leaning part and the fourth leaning part, a fourth supporting point is formed between the fourth supporting part and the fifth supporting part, and the fourth supporting point is abutted with the third supporting point.