Backrest angle stepless adjusting structure of seat

Abstract

The utility model discloses a backrest angle stepless adjusting structure of a seat, and aims to overcome the defects that when the angle of an existing backrest is adjusted, only several set angles of the backrest can be adjusted, a user can only switch among several fixed gears for use, and the experience feeling is poor. The chair comprises armrests connected with a backrest and foot connecting pieces connected with chair feet, the foot connecting pieces are connected with the armrests in a sliding mode to achieve stepless adjustment of the angle of the backrest, locking mechanisms are installed between the foot connecting pieces and the armrests, and the locking mechanisms achieve locking and positioning after the foot connecting pieces and the armrests are adjusted in place in a sliding mode. The backrest angle stepless adjusting structure of the seat enables the backrest to achieve infinite angle adjustment within the adjusting range, and the using comfort and the adjusting convenience of the seat are improved.

Description

Technical Field

[0001] The utility model relates to a seat, and more specifically to a stepless adjustment structure for a backrest angle of the seat. Background Art

[0002] Existing chairs with adjustable backrest angles generally consist of an armrest with fixed gears connected to a backrest, and a sliding column on the leg tube connector that matches the armrest gear. By pulling the armrest, the sliding column on the leg tube connector is positioned at different gears to achieve the use of the backrest at different angles. There are some defects in adjusting the angle of the backrest by pulling the armrest. The backrest can only be adjusted to a few set angles, and the adjustment of the backrest requires the user to lift the armrest and push and pull to complete the operation. This type of backrest angle adjustment limits the user's experience. The user can only switch between these fixed gears, which has a poor experience.

[0003] Chinese patent announcement number CN 218898928 U, announcement date April 25, 2023, discloses a folding chair with an adjustable backrest angle. It can adjust the angle of the folding chair backrest, but can only adjust the backrest to a few set angles. Users can only switch among these fixed gears, which has a poor experience. Utility Model Content

[0004] In order to overcome the above-mentioned shortcomings, the utility model provides a stepless adjustment structure for the backrest angle of a seat, so that the backrest can be adjusted to an infinite angle within the adjustment range, thereby increasing the comfort of the seat and the convenience of adjustment.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions: a stepless adjustment structure for the backrest angle of a seat, comprising an armrest connected to the backrest and a foot connector connected to the chair leg, the foot connector and the armrest are slidably connected to realize stepless adjustment of the backrest angle, a locking mechanism is installed between the foot connector and the armrest, and the locking mechanism realizes locking and positioning of the foot connector and the armrest after they are slidably adjusted into place.

[0006] The armrest and the chair leg are connected by the foot connector and the locking mechanism. When the backrest angle needs to be adjusted, the relative position between the foot connector and the armrest is adjusted. After the position is adjusted to the right position, the locking mechanism realizes the locking position after the foot connector and the armrest are slid and adjusted to the right position. Since the foot connector and the armrest are slidably connected to realize the stepless adjustment of the backrest angle, the backrest can be adjusted to an unlimited angle within the adjustment range, which increases the comfort of the chair and the convenience of adjustment.

[0007] Preferably, a slide groove is provided on the armrest, and a slide column is provided on the foot connecting piece. The slide column is adaptively connected to the slide groove, and the slide column can slide along the slide groove.

[0008] The foot connecting piece slides in the slide groove arranged on the armrest through the slide column, so that the backrest can be adjusted to an infinite angle within the adjustment range, and the sliding process is smooth and reliable.

[0009] Preferably, an angle adjusting member is installed on the armrest, a slide groove is arranged on the angle adjusting member, and a locking mechanism is arranged between the angle adjusting member and the foot connecting member.

[0010] An angle adjustment piece is installed on the armrest, which is convenient for setting the slide slot and installing the locking mechanism. The angle adjustment piece can be detachably connected to the armrest, which is convenient for designing different armrest shapes and replacing them in the future.

[0011] Preferably, the angle adjusting member comprises a left adjusting member and a right adjusting member, and slide grooves are arranged on the opposite surfaces of the left adjusting member and the right adjusting member, and the two ends of the slide column are respectively installed in the two slide grooves.

[0012] Both ends of the slide column on the foot connecting part are installed in two slide grooves of the left adjusting part and the right adjusting part, so that the backrest angle adjustment process is smoother.

[0013] Preferably, a plurality of left latches and right latches are respectively provided on the upper edges of the opposite sides of the left adjusting member and the right adjusting member, a left latching slot is correspondingly provided on the left adjusting member and the right latch, and a right latching slot is correspondingly provided on the right adjusting member and the left latch, the left latch and the right latch are adapted to be snap-fitted, and the right latch and the left latch are adapted to be snap-fitted.

[0014] The left clamping tongue is adapted to be clamped with the right clamping slot, and the right clamping tongue is adapted to be clamped with the left clamping slot, thereby realizing a reliable connection between the left adjusting member and the right adjusting member and facilitating the assembly of parts.

[0015] Preferably, the locking mechanism includes a toothed strip and a lock buckle, a locking head adapted to the toothed strip is provided on the lock buckle, the lock buckle is rotatably arranged, and the toothed strip is fixedly arranged, and the lock buckle rotates so that the locking head presses against the toothed strip to achieve locking.

[0016] When the backrest angle needs to be adjusted, the lock buckle is rotated in the opposite direction to separate the locking head from the toothed strip to unlock. When the backrest angle is adjusted to the desired position, the lock buckle is rotated to lock the locking head against the toothed strip. The locking mechanism has a simple structure, is easy to lock and unlock, and is reliable.

[0017] Preferably, the lock buckle is rotatably mounted on the foot connector, and the toothed strip is arranged on the armrest.

[0018] The lock is mounted on the foot connector for easy operation without interference.

[0019] Preferably, a pull ring is provided on the lock buckle.

[0020] The setting of the pull ring is convenient for fingers to pull the lock buckle to rotate.

[0021] Preferably, a tension spring is installed between the foot connector and the armrest.

[0022] When the user sits on the seat and leans against the backrest to adjust it backward, the angle of the backrest increases, and the tension spring acts as a resistance protection, allowing the backrest to slowly adjust to the maximum angle. When the user adjusts the backrest from a large angle to a small angle, the user turns the lock on the foot connector to disengage the locking head on the lock from the toothed strip on the armrest, and the backrest automatically returns to the small angle state with the help of the tension spring; by using the tension spring structure, the inconvenience of the traditional seat armrest adjustment structure requiring the armrest to be lifted and pulled with force is solved.

[0023] Preferably, an inserting head and an articulated head are provided on the foot connecting member, an articulated seat is rotatably mounted on the articulated head, and the articulated seat and the inserting head are respectively inserted at the upper ends of the front and rear chair legs.

[0024] The foot connector realizes a reliable connection between the front and rear chair feet.

[0025] Compared with the prior art, the beneficial effects of the utility model are as follows: (1) The stepless adjustment structure of the backrest angle of the seat enables the backrest to be adjusted to an infinite angle within the adjustment range, thereby increasing the comfort of the seat and the convenience of adjustment; (2) The locking mechanism has a simple structure, and the locking and unlocking operations are convenient and reliable; (3) When the user sits on the seat and presses against the backrest to adjust it backward, the angle of the backrest is increased, and the tension spring plays a role of resistance protection, so that the backrest is slowly adjusted to the maximum angle. When the user adjusts the backrest from a large angle to a small angle, the user turns the lock buckle on the foot connector to disengage the locking head on the lock buckle from the toothed strip on the armrest, and the backrest automatically returns to the small angle state with the help of the tension spring; by using the tension spring structure, the inconvenience of the traditional seat armrest adjustment structure requiring the armrest to be lifted and pulled with force is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the utility model;

[0027] Figure 2 It is a partial schematic diagram of the position of the foot connection member of the utility model;

[0028] Figure 3 It is a structural schematic diagram of the angle adjustment member of the utility model;

[0029] Figure 4 It is a structural schematic diagram of the foot connecting member of the utility model;

[0030] In the figure: 1, backrest, 2, armrest, 3, chair leg, 4, leg connector, 5, plug-in head, 6, hinge head, 7, hinge seat, 8, locking mechanism, 9, tension spring, 10, slide groove, 11, slide column, 12, angle adjustment member, 13, left adjustment member, 14, right adjustment member, 15, left latch, 16, right latch, 17, left slot, 18, right slot, 19, toothed strip, 20, lock buckle, 21, pull ring, 22, locking head, 23, seat, 24, cross bar, 25, avoidance groove, 26, connecting convex angle, 27, hinged ear, 28, connecting ear, 29, front pull hole, 30, support, 31, rear pull hole, 32, end plug, 33, convex. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0032] Embodiment 1: A stepless adjustment structure for the backrest angle of a seat (see attached Figure 1 , Attachment Figure 2 , Attachment Figure 4 ), including an armrest 2 connected to the backrest 1 and a foot connector 4 connected to the chair leg 3, a plug-in head 5 and a hinge head 6 are arranged on the foot connector 4, a hinge seat 7 is rotatably installed on the hinge head 6, and the hinge seat 7 and the plug-in head 5 are respectively plugged into the upper ends of the front and rear chair legs 3. The foot connector 4 is slidably connected to the armrest 2 to realize stepless adjustment of the angle of the backrest 1, and a locking mechanism 8 is installed between the foot connector 4 and the armrest 2, and the locking mechanism 8 realizes the locking and positioning of the foot connector 4 and the armrest 2 after the sliding adjustment is in place. A tension spring 9 is installed between the foot connector 4 and the armrest 2.

[0033] The armrest 2 is provided with a slide groove 10, and the foot connector 4 is provided with a slide column 11. The slide column 11 is adapted to be connected with the slide groove 10, and the slide column 11 can slide along the slide groove 10. An angle adjustment member 12 is installed on the armrest 2, and the slide groove 10 is arranged on the angle adjustment member 12, and the locking mechanism 8 is arranged between the angle adjustment member 12 and the foot connector 4. The foot connector slides in the slide groove arranged on the armrest through the slide column, so that the backrest can be adjusted to an infinite angle within the adjustment range, and the sliding process is smooth and reliable. The angle adjustment member 12 includes a left adjustment member 13 and a right adjustment member 14, and the slide grooves 10 are arranged on the opposite surfaces of the left adjustment member 13 and the right adjustment member 14, and the two ends of the slide column 11 are respectively installed in the two slide grooves 10. The angle adjustment member is installed on the armrest, which is convenient for the setting of the slide groove and the installation of the locking mechanism. The angle adjustment member can be detachably connected to the armrest, which is convenient for the design of different armrest shapes and replacement.

[0034] The locking mechanism 8 includes a toothed strip 19 and a lock buckle 20. A pull ring 21 is provided on the lock buckle 20. A locking head 22 adapted to the toothed strip 19 is provided on the lock buckle 20. The locking head 22 has a toothed structure. The lock buckle 20 is rotatably arranged, and the toothed strip 19 is fixedly arranged. The lock buckle 20 rotates so that the locking head 22 presses against the toothed strip 19 to achieve locking. The lock buckle 20 is rotatably mounted on the foot connecting member 4, and the toothed strip 19 is arranged on the angle adjusting member 12 on the armrest 2.

[0035] Specifically, Figure 1 As shown, the chair includes a seat 23 and a backrest 1. The seat 23 is hinged to the front foot, and the lower part of the backrest 1 is hinged to the seat 23. The hinged position of the backrest 1 and the seat 23 is rotatably connected to the rear foot, and the upper ends of the front foot and the rear foot are rotatably connected through the foot connector 4. The rear end of the armrest 2 is hinged to the side of the backrest 1. A crossbar 24 is connected between the two front feet and the two rear feet. The seat 23 is provided with seat rods on both sides, and the backrest is provided with backrest rods on both sides. Rotary joints are correspondingly provided between the rear ends of the two seat rods and the lower ends of the two backrest rods. The rear ends of the seat rods are rotatably connected to the rotatable joints, and the lower ends of the backrest rods are rotatably connected to the rotatable joints. A connecting rod is hinged between the rotatable joints and the rear foot, and the rotatable joints are abutted against the rear foot for positioning. The rear end of the armrest 2 is hinged to the backrest rod. The angle adjustment member 12 is installed on the lower surface of the armrest 2 to achieve hidden installation. The angle adjustment member 12 is fastened to the armrest 2 by screws. The angle adjustment member 12 includes a left adjustment member 13 and a right adjustment member 14, an avoidance groove 25 is formed between the left adjustment member 13 and the right adjustment member 14, a connection convex angle 26 is arranged on the foot connection member 4, the slide column 11 is arranged on the connection convex angle 26, and the locking head 22 and the connection convex angle 26 can pass through the avoidance groove 25. The slide groove 10 is arranged on the side wall of the avoidance groove 25, and the toothed strip 19 is arranged on the bottom surface of the avoidance groove 25.

[0036] like Figure 2 As shown, the foot connector 4 is provided with an insert head 5 which is inserted and connected with the upper end of the rear chair leg, and screws are connected between the rear chair leg and the insert head 5 to achieve fastening and locking. The hinge head 6 is a circular structure and protrudes from the front side of the foot connector 4, and the hinge seat 7 and the hinge head 6 are rotatably connected through a hinge shaft. The foot connector 4 is provided with an outwardly extending hinge ear 27 near the hinge head 6, and the lock buckle 20 is rotatably connected with the hinge ear 27. The side of the lock buckle 20 and the hinge ear 27 are closely fitted to increase the friction force, so that the lock buckle 20 will not rotate easily. A connecting ear 28 is provided at the rear side of the foot connector 4, and a front pull hole 29 is provided on the connecting ear 28. A support 30 is provided at the rear end of the armrest 2, and a rear pull hole 31 is provided on the support 30. The tension spring 9 is connected between the front pull hole 29 and the rear pull hole 31. The armrest 2 is a hollow structure, and end plugs 32 are installed at both ends. The armrest 2 with a hollow structure can reduce weight and reduce costs.

[0037] like Figure 4As shown, the foot connector 4 is an integral structure, and a plurality of circles of protrusions 33 are arranged on the outer wall of the insertion head 5 of the foot connector 4. The arrangement of the protrusions 33 can increase the tightness of the insertion head 5 and the rear chair leg 3. The lock buckle 20 is circular, and the locking head 22 and the pull ring 21 are arranged on the outer wall of the lock buckle 20. The locking head 22 is a V-shaped structure, and the lock buckle 20, the locking head 22, and the pull ring 21 are an integral structure. When the pull ring 21 is pulled forward to the bottom and touches the hinge head 6, the locking head 22 is locked to the toothed strip 19 and locked in place. Through this structural arrangement, it is convenient to rotate the lock buckle 20 to the fully locked position.

[0038] In this patent, the armrest 2 and the chair leg 3 are connected by the foot connector 4 and the locking mechanism 8. When the angle of the backrest 1 needs to be adjusted, the relative position between the foot connector 4 and the armrest 2 is adjusted. After the position is adjusted to the right position, the locking mechanism 8 realizes the locking position after the foot connector 4 and the armrest 2 are slid and adjusted to the right position. Since the foot connector 4 and the armrest 2 are slidably connected to realize the stepless adjustment of the angle of the backrest 1, the backrest 1 can be adjusted to an infinite angle within the adjustment range, which increases the comfort of the seat and the convenience of adjustment. The foot connector 4 slides in the slide groove 10 set on the armrest 2 through the slide column 11, so that the backrest 1 can be adjusted to an infinite angle within the adjustment range, and the sliding process is smooth and reliable. The two ends of the slide column 11 on the foot connector 4 are installed in the two slide grooves 10 of the left adjustment member 13 and the right adjustment member 14, and the angle adjustment process of the backrest 1 is smoother. When the angle of the backrest 1 needs to be adjusted, the lock buckle 20 is rotated in the opposite direction to separate the locking head 22 from the toothed strip 19 to achieve unlocking. When the angle of the backrest 1 is adjusted to the right position, the lock buckle 20 rotates to make the locking head 22 press against the toothed strip 19 to achieve locking. The locking mechanism 8 has a simple structure, convenient locking and unlocking operations, and reliable locking.

[0039] The user sits on the seat and leans against the backrest 1 to adjust it backwards. The angle of the backrest 1 is increased, and the tension spring 9 plays a role of resistance protection, so that the backrest 1 is slowly adjusted to the maximum angle. When the user adjusts the large angle of the backrest 1 to a small angle, the user rotates the lock buckle 20 on the foot connector 4 to disengage the locking head 22 on the lock buckle 20 from the toothed strip 19 on the armrest 2. The backrest 1 automatically returns to the small angle state with the help of the tension spring 9; by using the tension spring 9 structure, the inconvenience of the traditional seat armrest 2 adjustment structure requiring the armrest 2 to be lifted and pulled with force is solved.

[0040] Embodiment 2: A stepless adjustment structure for the backrest angle of a seat (see attached Figure 1 To Attachment Figure 4), including an armrest 2 connected to the backrest 1 and a foot connector 4 connected to the chair leg 3, a plug-in head 5 and a hinge head 6 are arranged on the foot connector 4, a hinge seat 7 is rotatably installed on the hinge head 6, and the hinge seat 7 and the plug-in head 5 are respectively plugged into the upper ends of the front and rear chair legs 3. The foot connector 4 is slidably connected to the armrest 2 to realize stepless adjustment of the angle of the backrest 1, and a locking mechanism 8 is installed between the foot connector 4 and the armrest 2, and the locking mechanism 8 realizes the locking and positioning of the foot connector 4 and the armrest 2 after the sliding adjustment is in place. A tension spring 9 is installed between the foot connector 4 and the armrest 2.

[0041] A slide groove 10 is provided on the armrest 2, and a slide column 11 is provided on the foot connector 4. The slide column 11 is adapted to be connected with the slide groove 10, and the slide column 11 can slide along the slide groove 10. An angle adjustment member 12 is installed on the armrest 2, and the slide groove 10 is provided on the angle adjustment member 12, and a locking mechanism 8 is provided between the angle adjustment member 12 and the foot connector 4. The foot connector slides in the slide groove provided on the armrest through the slide column, so that the backrest can be adjusted to an infinite angle within the adjustment range, and the sliding process is smooth and reliable. The angle adjustment member 12 includes a left adjustment member 13 and a right adjustment member 14, and the slide grooves 10 are provided on the opposite surfaces of the left adjustment member 13 and the right adjustment member 14, and the two ends of the slide column 11 are respectively installed in the two slide grooves 10. A plurality of left latches 15 and right latches 16 are respectively arranged on the upper edges of the opposite sides of the left adjusting member 13 and the right adjusting member 14. A left latching slot 17 is arranged on the left adjusting member 13 and the right latching slot 16, and a right latching slot 18 is arranged on the right adjusting member 14 and the left latching slot 15. The left latching slot 15 is adapted to be snap-fitted with the right latching slot 18, and the right latching slot 16 is adapted to be snap-fitted with the left latching slot 17. An angle adjusting member is installed on the armrest to facilitate the setting of the slide slot and the installation of the locking mechanism. The angle adjusting member can be detachably connected to the armrest, so that it is convenient to design different armrest shapes for replacement in the future.

[0042] The locking mechanism 8 includes a toothed strip 19 and a lock buckle 20. A pull ring 21 is provided on the lock buckle 20. A locking head 22 adapted to the toothed strip 19 is provided on the lock buckle 20. The locking head 22 has a toothed structure. The lock buckle 20 is rotatably arranged, and the toothed strip 19 is fixedly arranged. The lock buckle 20 rotates so that the locking head 22 presses against the toothed strip 19 to achieve locking. The lock buckle 20 is rotatably mounted on the foot connecting member 4, and the toothed strip 19 is arranged on the angle adjusting member 12 on the armrest 2.

[0043] Specifically, Figure 1As shown, the chair includes a seat 23 and a backrest 1. The seat 23 is hinged to the front foot, and the lower part of the backrest 1 is hinged to the seat 23. The hinged position of the backrest 1 and the seat 23 is rotatably connected to the rear foot, and the upper ends of the front foot and the rear foot are rotatably connected through the foot connector 4. The rear end of the armrest 2 is hinged to the side of the backrest 1. A crossbar 24 is connected between the two front feet and the two rear feet. The seat 23 is provided with seat rods on both sides, and the backrest is provided with backrest rods on both sides. Rotary joints are correspondingly provided between the rear ends of the two seat rods and the lower ends of the two backrest rods. The rear ends of the seat rods are rotatably connected to the rotatable joints, and the lower ends of the backrest rods are rotatably connected to the rotatable joints. A connecting rod is hinged between the rotatable joints and the rear foot, and the rotatable joints are abutted against the rear foot for positioning. The rear end of the armrest 2 is hinged to the backrest rod. The angle adjustment member 12 is installed on the lower surface of the armrest 2 to achieve hidden installation. The angle adjustment member 12 is fastened to the armrest 2 by screws. The angle adjustment member 12 includes a left adjustment member 13 and a right adjustment member 14, an avoidance groove 25 is formed between the left adjustment member 13 and the right adjustment member 14, a connection convex angle 26 is arranged on the foot connection member 4, the slide column 11 is arranged on the connection convex angle 26, and the locking head 22 and the connection convex angle 26 can pass through the avoidance groove 25. The slide groove 10 is arranged on the side wall of the avoidance groove 25, and the toothed strip 19 is arranged on the bottom surface of the avoidance groove 25.

[0044] like Figure 2 As shown, the foot connector 4 is provided with an insert head 5 which is inserted and connected with the upper end of the rear chair leg, and screws are connected between the rear chair leg and the insert head 5 to achieve fastening and locking. The hinge head 6 is a circular structure and protrudes from the front side of the foot connector 4, and the hinge seat 7 and the hinge head 6 are rotatably connected through a hinge shaft. The foot connector 4 is provided with an outwardly extending hinge ear 27 near the hinge head 6, and the lock buckle 20 is rotatably connected with the hinge ear 27. The side of the lock buckle 20 and the hinge ear 27 are closely fitted to increase the friction force, so that the lock buckle 20 will not rotate easily. A connecting ear 28 is provided at the rear side of the foot connector 4, and a front pull hole 29 is provided on the connecting ear 28. A support 30 is provided at the rear end of the armrest 2, and a rear pull hole 31 is provided on the support 30. The tension spring 9 is connected between the front pull hole 29 and the rear pull hole 31. The armrest 2 is a hollow structure, and end plugs 32 are installed at both ends. The armrest 2 with a hollow structure can reduce weight and reduce costs.

[0045] like Figure 3As shown, the left adjusting member 13 and the right adjusting member 14 are both in a shell structure, and the left latch 15 and the right latch 16 are respectively arranged on the upper surface of the left adjusting member 13 and the right adjusting member 14 and protrude outward. The left latch 17 and the right latch 18 are respectively arranged at the opposite side edge positions of the upper surface of the left adjusting member 13 and the right adjusting member 14, the length of the left latch 17 is greater than the right latch 16, and the length of the right latch 18 is greater than the left latch 15. After the left latch 15 is adapted to be snap-fitted with the right latch 18 and the right latch 16 is adapted to be snap-fitted with the left latch 17, the left latch 15 and the right latch 16 are correspondingly locked together. The left latch is adapted to be snap-fitted with the right latch, and the right latch is adapted to be snap-fitted with the left latch, so as to realize the reliable connection between the left adjusting member and the right adjusting member and facilitate the assembly of parts.

[0046] like Figure 4 As shown, the foot connector 4 is an integral structure, and a plurality of circles of protrusions 33 are arranged on the outer wall of the insertion head 5 of the foot connector 4. The arrangement of the protrusions 33 can increase the tightness of the insertion head 5 and the rear chair leg 3. The lock buckle 20 is circular, and the locking head 22 and the pull ring 21 are arranged on the outer wall of the lock buckle 20. The locking head 22 is a V-shaped structure, and the lock buckle 20, the locking head 22, and the pull ring 21 are an integral structure. When the pull ring 21 is pulled forward to the bottom and touches the hinge head 6, the locking head 22 is locked to the toothed strip 19 and locked in place. Through this structural arrangement, it is convenient to rotate the lock buckle 20 to the fully locked position.

[0047] In this patent, the armrest 2 and the chair leg 3 are connected by the foot connector 4 and the locking mechanism 8. When the angle of the backrest 1 needs to be adjusted, the relative position between the foot connector 4 and the armrest 2 is adjusted. After the position is adjusted to the right position, the locking mechanism 8 realizes the locking position after the foot connector 4 and the armrest 2 are slid and adjusted to the right position. Since the foot connector 4 and the armrest 2 are slidably connected to realize the stepless adjustment of the angle of the backrest 1, the backrest 1 can be adjusted to an infinite angle within the adjustment range, which increases the comfort of the seat and the convenience of adjustment. The foot connector 4 slides in the slide groove 10 set on the armrest 2 through the slide column 11, so that the backrest 1 can be adjusted to an infinite angle within the adjustment range, and the sliding process is smooth and reliable. The two ends of the slide column 11 on the foot connector 4 are installed in the two slide grooves 10 of the left adjustment member 13 and the right adjustment member 14, and the angle adjustment process of the backrest 1 is smoother. When the angle of the backrest 1 needs to be adjusted, the lock buckle 20 is rotated in the opposite direction to separate the locking head 22 from the toothed strip 19 to achieve unlocking. When the angle of the backrest 1 is adjusted to the right position, the lock buckle 20 rotates to make the locking head 22 press against the toothed strip 19 to achieve locking. The locking mechanism 8 has a simple structure, convenient locking and unlocking operations, and reliable locking.

[0048] The above-described embodiments are only preferred solutions of the present invention and are not intended to limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. A stepless adjustment structure for the backrest angle of a chair, comprising an armrest connected to the backrest and a foot connector connected to the chair foot, characterized in that: The foot connector is slidably connected to the armrest to achieve stepless adjustment of the backrest angle. A locking mechanism is installed between the foot connector and the armrest to achieve locking and positioning of the foot connector and the armrest after the sliding adjustment is in place.

2. The seat backrest angle stepless adjustment structure according to claim 1 is characterized in that: A slide groove is arranged on the handrail, a slide column is arranged on the foot connecting piece, the slide column is adaptively connected with the slide groove, and the slide column can slide along the slide groove.

3. The seat backrest angle stepless adjustment structure according to claim 2 is characterized in that: An angle adjusting piece is installed on the armrest, a sliding groove is arranged on the angle adjusting piece, and a locking mechanism is arranged between the angle adjusting piece and the foot connecting piece.

4. The seat backrest angle stepless adjustment structure according to claim 3 is characterized in that: The angle adjusting member comprises a left adjusting member and a right adjusting member. Slide grooves are arranged on the opposite surfaces of the left adjusting member and the right adjusting member. The two ends of the slide column are respectively installed in the two slide grooves.

5. The seat backrest angle stepless adjustment structure according to claim 4 is characterized in that: A plurality of left latches and right latches are respectively arranged on the upper edges of the opposite sides of the left adjusting member and the right adjusting member, a left latching slot is correspondingly arranged on the left adjusting member and the right latching slot is correspondingly arranged on the right adjusting member and the left latching slot, the left latching slot is adapted to be snap-fitted into the right latching slot, and the right latching slot is adapted to be snap-fitted into the left latching slot.

6. The seat backrest angle stepless adjustment structure according to claim 1, characterized in that: The locking mechanism comprises a toothed strip and a lock buckle. A locking head matched with the toothed strip is arranged on the lock buckle. The lock buckle is rotatably arranged and the toothed strip is fixedly arranged. The lock buckle rotates so that the locking head presses against the toothed strip to realize locking.

7. The seat backrest angle stepless adjustment structure according to claim 6, characterized in that: The lock buckle is rotatably mounted on the foot connecting piece, and the toothed strip is arranged on the armrest.

8. The seat backrest angle stepless adjustment structure according to claim 6, characterized in that: A pull ring is provided on the lock buckle.

9. A seat backrest angle stepless adjustment structure according to any one of claims 1 to 8, characterized in that: A tension spring is installed between the foot connecting piece and the armrest.

10. A seat backrest angle stepless adjustment structure according to any one of claims 1 to 8, characterized in that: An inserting head and an articulated head are arranged on the foot connecting piece, an articulated seat is rotatably installed on the articulated head, and the articulated seat and the inserting head are respectively inserted at the upper ends of the front and rear chair feet.

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