Backrest stepless adjusting chair

Abstract

The utility model discloses a chair with a steplessly adjustable backrest, and aims to overcome the defect that the use experience of a user is limited as the backrest of the chair can only be adjusted at a plurality of specific angles. The chair comprises a chair seat and a backrest which are rotationally connected together, the chair seat is connected with supporting legs, the backrest is connected with armrests, and a stepless adjusting mechanism is arranged between the armrests and the supporting legs and comprises a locking strip, a locking pin and a locking pin, a locking block; the lock catch can drive the locking block to move in the direction of the locking strip and enable the locking block and the locking strip to be attached and locked. According to the backrest stepless adjustment chair, stepless adjustment of the angle of the seat backrest can be achieved, a user can conveniently select a comfortable backrest angle, and the use experience is good.

Description

Technical Field

[0001] The utility model relates to a chair, more specifically, to a chair with a stepless backrest adjustment. Background Art

[0002] Chairs are necessities in people's daily lives. In order to improve the comfort of seats, many seats can now adjust the backrest angle. Among them, adjusting the backrest angle through the armrest is a common adjustment method. When adjusting, pull the armrest to lock the fixed gear installed on the armrest with the locking column installed on the leg tube to achieve positioning. The locking column is locked in different positions on the fixed gear to achieve different backrest angle adjustments. This adjustment method only has a few set angles that can be used, which limits the user experience and cannot achieve stepless adjustment of the backrest angle, affecting the user experience. Utility Model Content

[0003] In order to overcome the above-mentioned shortcomings, the utility model provides a chair with a stepless backrest adjustment, which can achieve stepless adjustment of the seat back angle, making it convenient for users to choose a comfortable backrest angle and providing a good user experience.

[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions: a chair with a stepless backrest adjustment, comprising a seat and a backrest connected together by rotation, the seat is connected to the support leg, the backrest is connected to the armrest, and a stepless adjustment mechanism is arranged between the armrest and the support leg, and the stepless adjustment mechanism includes:

[0005] Locking strip;

[0006] Locking block;

[0007] The lock buckle can drive the locking block to move toward the locking strip and make the locking block fit and lock with the locking strip.

[0008] The seat is supported by the legs. When the backrest angle needs to be adjusted, first move the lock to separate the locking block from the locking strip to unlock it, then pull the armrest to adjust the backrest angle. After the angle is adjusted, move the lock in the opposite direction to drive the locking block to move in the direction of the locking strip and lock the locking block and the locking strip together. Since there is no fixed gear between the locking strip and the locking block, the locking block can be locked at any position of the locking strip, so that the backrest angle can be adjusted steplessly. The stepless backrest adjustment chair of this patent application can achieve stepless adjustment of the seat backrest angle, which is convenient for users to choose a comfortable backrest angle and provides a good user experience.

[0009] Preferably, a slide groove is provided on the locking strip, a slide column is connected to the support leg, and the end of the slide column is movably inserted in the slide groove for sliding.

[0010] When the handrail is pulled, the slide column presses the slide groove to slide, ensuring the stability and reliability of the handrail connection.

[0011] Preferably, a locking groove is provided on the locking strip, a clamping groove is provided on the locking block, and a pushing head is provided on the lock buckle. The two side surfaces of the pushing head are inclined to form a pushing surface. The pushing head moves so that the pushing surface abuts against the side walls of the clamping groove to push the two sides of the locking block toward the locking groove, thereby making the side walls of the locking block fit and lock with the side walls of the locking groove.

[0012] A clamping groove is arranged on the locking block so that the locking block has a U-shaped structure, and the locking block is pushed toward the side wall of the locking groove by an inclined pushing surface, so that the side wall of the locking block and the side wall of the locking groove are fitted and locked, thereby fixing the backrest.

[0013] Preferably, a locking rack is provided on the side wall of the locking groove, and a convex tooth is provided on the locking block, and the convex tooth is engaged and locked with the locking rack.

[0014] When the side wall of the locking block fits and locks with the side wall of the locking groove, the convex teeth on the locking block and the locking rack on the side wall of the locking groove are engaged and locked, which improves the locking effect and further improves the stability of the backrest angle fixation.

[0015] Preferably, the lock buckle is rotatably mounted in the clamping groove.

[0016] The lock buckle is arranged to rotate, so as to facilitate pushing the locking block to lock and unlock the locking strip.

[0017] Preferably, a tension spring is connected between the rear portion of the armrest and the support foot.

[0018] When the user adjusts the backrest tube to a larger angle, he or she leans against the backrest to adjust it backwards. The tension spring acts as a resistance protection, allowing the backrest to slowly adjust to the maximum angle. When the user adjusts the backrest tube from a large angle to a small angle, the backrest automatically returns to the small angle state with the help of the tension spring. The use of the tension spring structure solves the inconvenience of the traditional seat armrest adjustment structure that requires the armrest to be lifted and pulled.

[0019] Preferably, the locking strip comprises a left adjusting member and a right adjusting member which are arranged opposite to each other, the locking block is placed between the left adjusting member and the right adjusting member, the opposite surfaces of the left adjusting member and the right adjusting member are locking surfaces, and the locking block is locked by fitting with the locking surfaces.

[0020] The locking strip formed by connecting the left adjusting piece and the right adjusting piece facilitates processing and assembly.

[0021] Preferably, a connecting piece is arranged at the upper end of the supporting leg, a locking block is arranged on the connecting piece, and a locking strip is arranged on the armrest.

[0022] The locking block is arranged on the connecting piece, and the processing is convenient.

[0023] Preferably, the connecting member includes a fixed seat and a rotating seat, the rotating seat is rotatably mounted on the fixed seat, and the locking block is arranged on the fixed seat; the supporting leg includes a front leg and a rear leg, the upper end of the front leg is plug-in connected to the rotating seat, and the upper end of the rear leg is plug-in connected to the fixed seat.

[0024] The connecting piece is composed of a fixed seat and a rotating seat, which facilitates the connection between the front foot and the rear foot.

[0025] Preferably, both ends of the armrest are connected with end caps, and the rear of the armrest is rotatably connected to the side of the backrest.

[0026] The end cap serves a decorative purpose, and the armrests and backrest are rotatably connected to facilitate folding of the seat.

[0027] Compared with the prior art, the beneficial effects of the utility model are: (1) the chair with stepless backrest adjustment of the patent application can realize stepless adjustment of the seat backrest angle, which is convenient for users to choose a comfortable backrest angle and has a good user experience; (2) through the use of tension springs, the adjustment of the backrest has an auxiliary and protective effect; (3) the stepless adjustment mechanism is an independent unit, which is convenient for future design of different seats to be replaced. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the utility model;

[0029] Figure 2 It is a schematic diagram of the position of the stepless adjustment mechanism of the utility model;

[0030] Figure 3 It is an exploded view of the stepless adjustment mechanism of the utility model;

[0031] In the figure: 1, seat, 2, backrest, 3, cross bar, 4, armrest, 5, end cover, 6, stepless adjustment mechanism, 7, locking block, 8, lock, 9, slide groove, 10, slide column, 11, clamping groove, 12, pushing head, 13, pushing surface, 14, locking rack, 15, convex tooth, 16, rotating pin, 17, push-pull block, 18, tension spring, 19, connecting piece, 20, fixed seat, 21, rotating seat, 22, front foot, 23, rear foot, 24, left adjusting piece, 25, right adjusting piece, 26, seat support rod, 27, backrest support rod, 28, adapter, 29, connecting rod, 30, support, 31, connecting ear, 32, left card slot, 33, left card head, 34, right card slot, 35, right card head, 36, connecting plate, 37, extension ear, 38, convex head. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0033] Embodiment 1: A stepless backrest adjustment chair (see attached Figure 1To Attachment Figure 3 ), comprising a seat 1 and a backrest 2 which are rotatably connected together, the rear end of the seat 1 is rotatably connected to the lower end of the backrest 2, the seat 1 is connected to the support foot, the backrest 2 is connected to the armrest 4, the rear part of the armrest 4 is rotatably connected to the side of the backrest 2, and a stepless adjustment mechanism 6 is arranged between the armrest 4 and the support foot, and the stepless adjustment mechanism 6 comprises:

[0034] A locking strip, which is fixedly mounted on the armrest 4;

[0035] A locking block 7, wherein the locking block 7 is fixedly mounted on the supporting foot;

[0036] The lock buckle 8 can drive the locking block 7 to move toward the locking strip and make the locking block 7 fit and lock with the locking strip.

[0037] A slide groove 9 is provided on the locking bar, and a slide column 10 is connected to the support leg. The end of the slide column 10 is movably inserted in the slide groove 9 to slide. A locking groove is provided on the locking bar, and slide grooves 9 are provided on both side walls of the locking groove. The two ends of the slide seat are respectively placed in the two slide grooves 9. A clamping groove 11 is provided on the locking block 7, and a push head 12 is provided on the lock buckle 8. The two sides of the push head 12 are inclined to form a push surface 13. The push head 12 moves so that the push surface 13 abuts against the side wall of the clamping groove 11 to push the two sides of the locking block 7 toward the locking groove direction, thereby making the side wall of the locking block 7 fit and lock with the side wall of the locking groove. A locking rack 14 is provided on the side wall of the locking groove, and a convex tooth 15 is provided on the locking block 7. The convex tooth 15 is locked by clamping with the locking rack 14. The lock buckle 8 is rotatably installed in the clamping groove 11, and a rotating pin 16 is connected between the lock buckle 8 and the locking block 7. A push-pull block 17 is arranged on the lock catch 8 away from the push head 12 end, and the arrangement of the push-pull block 17 facilitates the rotation of the push-pull lock catch 8. A tension spring 18 is connected between the rear portion of the armrest 4 and the supporting foot.

[0038] A connecting member 19 is arranged at the upper end of the supporting leg, a locking block 7 is arranged on the connecting member 19, a sliding column 10 is arranged on the connecting member 19, a tension spring 18 is connected to the connecting member 19, and a locking strip is arranged on the armrest 4. The connecting member 19 includes a fixed seat 20 and a rotating seat 21, the rotating seat 21 is rotatably mounted on the fixed seat 20, the sliding column 10 and the locking block 7 are arranged on the fixed seat 20, and the tension spring 18 is connected to the fixed seat 20; the supporting leg includes a front leg 22 and a rear leg 23, the upper end of the front leg 22 is plug-connected to the rotating seat 21, and the upper end of the rear leg 23 is plug-connected to the fixed seat 20.

[0039] The locking strip includes a left adjusting member 24 and a right adjusting member 25 which are arranged opposite to each other. The locking block 7 is placed between the left adjusting member 24 and the right adjusting member 25. The opposite surfaces of the left adjusting member 24 and the right adjusting member 25 are locking surfaces. The locking block 7 is locked in contact with the locking surfaces.

[0040] The left and right sides of the stepless backrest adjustment chair are equipped with armrests 4 and legs, and stepless adjustment mechanisms 6 are installed between the two armrests 4 and the two legs. The armrests 4 are placed above the stepless adjustment mechanisms 6, and a support 30 is arranged at the rear of the armrests 4, and a rear connection hole is arranged on the support 30. A connection ear 31 is arranged on the fixed seat 20 of the upper end connector 19 of the leg, and a front connection hole is arranged on the connection ear 31. The two ends of the tension spring 18 are respectively connected to the front connection hole and the rear connection hole. When the user adjusts the angle of the backrest 2 tube to increase, he leans against the backrest 2 to adjust it backward, and the tension spring 18 plays a role of resistance protection, so that the backrest 2 is slowly adjusted to the maximum angle. When the user adjusts the large angle of the backrest 2 tube to a small angle, the backrest 2 automatically returns to the state of the small angle with the help of the tension spring 18. By using the tension spring 18 structure, the inconvenience of the traditional seat armrest 4 adjustment structure that requires the armrest 4 to be lifted and pulled with force is solved. A crossbar 3 is connected between the two front feet 22 and between the two rear feet 23.

[0041] The locking strip is formed by connecting the left adjusting member 24 and the right adjusting member 25, which is convenient for processing and assembly. A left card slot 32 is provided on the upper surface of the left adjusting member 24 near the edge of the right adjusting member 25, and a protruding left card head 33 is provided on the side wall of the left card slot 32. A right card slot 34 is provided on the upper surface of the right adjusting member 25 near the edge of the left adjusting member 24, and a protruding right card head 35 is provided on the side wall of the right card slot 34. The left card head 33 is adapted to be inserted in the right card slot 34, and the right card head 35 is adapted to be inserted in the left card slot 32, thereby realizing the assembly positioning of the left adjusting member 24 and the right adjusting member 25. The left adjusting member 24 and the right adjusting member 25 are both fastened to the armrest 4. The slide groove 9 and the locking rack 14 are provided on the opposite sides of the left adjusting member 24 and the right adjusting member 25, and the locking groove is placed between the left adjusting member 24 and the right adjusting member 25. A groove is provided on the lower surface of the armrest 4 corresponding to the locking strip, and the locking strip is installed in the groove. Connecting plates 36 are provided at both ends of the left adjusting member 24 and the right adjusting member 25, and the left adjusting member 24 and the right adjusting member 25 are fastened to the lower surface of the armrest 4 through the connecting plates 36.

[0042] An extension ear 37 is arranged on the fixed seat 20 of the connecting member 19 and corresponds to the slide post 10. The extension ear 37 and the fixed seat 20 are integrally structured. The slide post 10 is arranged at the end of the extension ear 37. The axial length of the slide post 10 is greater than the thickness of the extension ear 37. The locking block 7 is in a U-shaped structure. The locking block 7 and the fixed seat 20 of the connecting member 19 are integrally structured. The convex teeth 15 are arranged on the two outer side walls of the locking block 7. A push head 12 is arranged at one end of the lock buckle 8, and a push-pull block 17 is arranged at the other end of the lock buckle 8. The push-pull block 17 is in a rectangular structure, which is convenient for manual operation of the lock buckle 8 to rotate. Inclined push surfaces 13 are arranged on both sides of the push head 12, so that after the push head 12 is rotated into the clamping groove 11, the two sides of the locking block 7 can be pushed toward the side wall of the locking groove, thereby causing the teeth to be engaged and locked with the locking rack 14. A convex head 38 is arranged on the lock buckle 8, which is biased towards the push head 12 side. The convex head 38 is rotatably connected with the locking block 7 through the rotating pin 16. The sliding groove 9 on the side wall of the locking groove is placed above the locking rack 14 .

[0043] The seat is supported by the legs. When the angle of the backrest 2 needs to be adjusted, the lock buckle 8 is first manually pulled to separate the push head 12 on the lock buckle 8 from the clamping groove 11 on the locking block 7. Under the elastic action of the locking block 7, the convex teeth 15 are separated from the locking rack 14 to achieve unlocking. Then the armrest 4 is pushed and pulled. During the pushing and pulling process, the slide column 10 slides in the slide groove 9 to ensure the stability of the sliding process of the armrest 4. During the pushing and pulling process of the armrest 4, the angle of the backrest 2 changes. When the angle of the backrest 2 is adjusted to the right position, the armrest 4 stops sliding and the lock buckle 8 is pulled in the opposite direction to make the push head 12 stuck in the clamping groove 11 to push the locking block 7 outward. The convex teeth 15 on the locking block 7 are stuck on the locking rack 14 on the side wall of the locking groove to achieve locking and positioning. Since there is no fixed gear set between the locking bar and the locking block 7, the locking block 7 can be locked at any position of the locking bar, so that the stepless adjustment of the angle of the backrest 2 can be achieved.

[0044] The locking block 7 is provided with a clamping groove 11 so that the locking block 7 has a U-shaped structure, and the locking block 7 is pushed toward the side wall of the locking groove by the inclined pushing surface 13, so that the side wall of the locking block 7 is fitted and locked with the side wall of the locking groove, thereby fixing the backrest 2. When the side wall of the locking block 7 is fitted and locked with the side wall of the locking groove, the convex teeth 15 on the locking block 7 are engaged and locked with the locking rack 14 on the side wall of the locking groove, thereby improving the locking effect and thus improving the stability of the angle fixation of the backrest 2. A tension spring 18 is used to connect the connecting piece 19 and the rear end of the armrest 4. When the user adjusts the angle of the backrest 2 to increase, he / she presses against the backrest 2 to adjust it backwards. The tension spring 18 plays a role of resistance protection, so that the backrest 2 is slowly adjusted to the maximum angle. When the user adjusts the large angle of the backrest 2 to a small angle, the lock buckle 8 is turned to disengage the push head 12 from the clamping groove 11, and the convex tooth 15 disengages the locking rack 14. The backrest 2 automatically returns to the state of the small angle with the help of the tension spring 18. By using the tension spring 18 structure, the inconvenience of the traditional seat armrest 4 adjustment structure requiring force to lift and pull the armrest 4 is solved. The stepless adjustment chair of the backrest 2 of this patent application can realize stepless adjustment of the angle of the seat backrest 2, which is convenient for users to choose a comfortable angle of the backrest 2 and has a good user experience.

[0045] Embodiment 2: A stepless backrest adjustment chair (see attached Figure 1 To Attachment Figure 3 ), including a seat 1 and a backrest 2 that are rotatably connected together, the rear end of the seat 1 is rotatably connected to the lower end of the backrest 2, the seat 1 is connected to the support foot, the support foot is an inverted V-shaped structure, the left and right sides of the seat 1 are equipped with support feet, the support feet on the left and right sides are connected with a cross bar 3, the backrest 2 is connected to an armrest 4, both ends of the armrest 4 are connected to an end cap 5, the rear of the armrest 4 is rotatably connected to the side of the backrest 2, a stepless adjustment mechanism 6 is arranged between the armrest 4 and the support foot, and the stepless adjustment mechanism 6 includes:

[0046] A locking strip, which is fixedly mounted on the armrest 4;

[0047] A locking block 7, wherein the locking block 7 is fixedly mounted on the supporting foot;

[0048] The lock buckle 8 can drive the locking block 7 to move toward the locking strip and make the locking block 7 fit and lock with the locking strip.

[0049] A slide groove 9 is provided on the locking bar, and a slide column 10 is connected to the support leg. The end of the slide column 10 is movably inserted in the slide groove 9 to slide. A locking groove is provided on the locking bar, and slide grooves 9 are provided on both side walls of the locking groove. The two ends of the slide seat are respectively placed in the two slide grooves 9. A clamping groove 11 is provided on the locking block 7, and a push head 12 is provided on the lock buckle 8. The two sides of the push head 12 are inclined to form a push surface 13. The push head 12 moves so that the push surface 13 abuts against the side wall of the clamping groove 11 to push the two sides of the locking block 7 toward the locking groove direction, thereby making the side wall of the locking block 7 fit and lock with the side wall of the locking groove. A locking rack 14 is provided on the side wall of the locking groove, and a convex tooth 15 is provided on the locking block 7. The convex tooth 15 is locked by clamping with the locking rack 14. The lock buckle 8 is rotatably installed in the clamping groove 11, and a rotating pin 16 is connected between the lock buckle 8 and the locking block 7. A push-pull block 17 is arranged on the lock catch 8 away from the push head 12 end, and the arrangement of the push-pull block 17 facilitates the rotation of the push-pull lock catch 8. A tension spring 18 is connected between the rear portion of the armrest 4 and the supporting foot.

[0050] A connecting member 19 is arranged at the upper end of the supporting leg, a locking block 7 is arranged on the connecting member 19, a sliding column 10 is arranged on the connecting member 19, a tension spring 18 is connected to the connecting member 19, and a locking strip is arranged on the armrest 4. The connecting member 19 includes a fixed seat 20 and a rotating seat 21, the rotating seat 21 is rotatably mounted on the fixed seat 20, the sliding column 10 and the locking block 7 are arranged on the fixed seat 20, and the tension spring 18 is connected to the fixed seat 20; the supporting leg includes a front leg 22 and a rear leg 23, the upper end of the front leg 22 is plug-connected to the rotating seat 21, and the upper end of the rear leg 23 is plug-connected to the fixed seat 20.

[0051] The locking strip includes a left adjusting member 24 and a right adjusting member 25 which are arranged opposite to each other. The locking block 7 is placed between the left adjusting member 24 and the right adjusting member 25. The opposite surfaces of the left adjusting member 24 and the right adjusting member 25 are locking surfaces. The locking block 7 is locked in contact with the locking surfaces.

[0052] like Figure 1 As shown, armrests 4 and legs are installed on both sides of the stepless backrest adjustment chair, and stepless adjustment mechanisms 6 are installed between the two armrests 4 and the two legs. The stepless adjustment mechanisms 6 on both sides are used to adjust the angle of the backrest 2, which is more stable and reliable. Seat support rods 26 are set on the left and right sides of the seat 1, and back support rods 27 are set on the left and right sides of the backrest 2. Adapters 28 are connected between the lower ends of the two back support rods 27 and the rear ends of the two seat support rods 26. The back support rods 27 and the seat support rods 26 are both rotatably connected to the adapter 28. The adapter 28 can abut against the rear foot 23 to achieve positioning, and a connecting rod 29 is hinged between the adapter 28 and the rear foot 23.

[0053] The end cover 5 at the rear end of the armrest 4 is connected to the armrest 4 by a pin shaft, and the pin shaft realizes the positioning of the end cover 5 and the armrest 4, and the backrest support rod 27 is rotatably connected to the pin shaft. The armrest 4 is placed above the stepless adjustment mechanism 6, and a support 30 is arranged at the rear of the armrest 4, and a rear connection hole is arranged on the support 30, and a connection ear 31 is arranged on the fixing seat 20 of the upper end connecting piece 19 of the support foot, and a front connection hole is arranged on the connection ear 31, and the two ends of the tension spring 18 are respectively connected to the front connection hole and the rear connection hole. When the user adjusts the angle of the backrest 2 tube to increase, the backrest 2 is adjusted backward by force, and the tension spring 18 plays a role of resistance protection, so that the backrest 2 is slowly adjusted to the maximum angle. When the user adjusts the large angle of the backrest 2 tube to a small angle, the backrest 2 automatically returns to the state of the small angle with the help of the tension spring 18. By using the tension spring 18 structure, the inconvenience of the traditional seat armrest 4 adjustment structure that the armrest 4 needs to be lifted and pulled by force is solved. A cross bar 3 is connected between the two front feet 22 and between the two rear feet 23.

[0054] like Figure 2 , Figure 3 As shown, the locking strip is formed by connecting the left adjusting member 24 and the right adjusting member 25, which facilitates processing and assembly. A left clamping groove 32 is provided on the upper surface of the left adjusting member 24 near the edge of the right adjusting member 25, and a protruding left clamping head 33 is provided on the side wall of the left clamping groove 32. A right clamping groove 34 is provided on the upper surface of the right adjusting member 25 near the edge of the left adjusting member 24, and a protruding right clamping head 35 is provided on the side wall of the right clamping groove 34. The left clamping head 33 is adapted to be inserted in the right clamping groove 34, and the right clamping head 35 is adapted to be inserted in the left clamping groove 32, thereby realizing the assembly positioning of the left adjusting member 24 and the right adjusting member 25. The left adjusting member 24 and the right adjusting member 25 are both fastened to the armrest 4. The slide groove 9 and the locking rack 14 are provided on the opposite sides of the left adjusting member 24 and the right adjusting member 25, and the locking groove is placed between the left adjusting member 24 and the right adjusting member 25. A groove is provided on the lower surface of the armrest 4 corresponding to the locking strip, and the locking strip is installed in the groove. Connecting plates 36 are provided at both ends of the left adjusting member 24 and the right adjusting member 25, and the left adjusting member 24 and the right adjusting member 25 are fastened to the lower surface of the armrest 4 through the connecting plates 36.

[0055] An extension ear 37 is arranged on the fixed seat 20 of the connecting member 19 and corresponds to the slide post 10. The extension ear 37 and the fixed seat 20 are integrally structured. The slide post 10 is arranged at the end of the extension ear 37. The axial length of the slide post 10 is greater than the thickness of the extension ear 37. The locking block 7 is in a U-shaped structure. The locking block 7 and the fixed seat 20 of the connecting member 19 are integrally structured. The convex teeth 15 are arranged on the two outer side walls of the locking block 7. A push head 12 is arranged at one end of the lock buckle 8, and a push-pull block 17 is arranged at the other end of the lock buckle 8. The push-pull block 17 is in a rectangular structure, which is convenient for manual operation of the lock buckle 8 to rotate. Inclined push surfaces 13 are arranged on both sides of the push head 12, so that after the push head 12 is rotated into the clamping groove 11, the two sides of the locking block 7 can be pushed toward the side wall of the locking groove, thereby causing the teeth to be engaged and locked with the locking rack 14. A convex head 38 is arranged on the lock buckle 8, which is biased towards the push head 12 side. The convex head 38 is rotatably connected with the locking block 7 through the rotating pin 16. The sliding groove 9 on the side wall of the locking groove is placed above the locking rack 14 .

[0056] The seat is supported by the legs. When the angle of the backrest 2 needs to be adjusted, the lock buckle 8 is first manually pulled to separate the push head 12 on the lock buckle 8 from the clamping groove 11 on the locking block 7. Under the elastic action of the locking block 7, the convex teeth 15 are separated from the locking rack 14 to achieve unlocking. Then the armrest 4 is pushed and pulled. During the pushing and pulling process, the slide column 10 slides in the slide groove 9 to ensure the stability of the sliding process of the armrest 4. During the pushing and pulling process of the armrest 4, the angle of the backrest 2 changes. When the angle of the backrest 2 is adjusted to the right position, the armrest 4 stops sliding and the lock buckle 8 is pulled in the opposite direction to make the push head 12 stuck in the clamping groove 11 to push the locking block 7 outward. The convex teeth 15 on the locking block 7 are stuck on the locking rack 14 on the side wall of the locking groove to achieve locking and positioning. Since there is no fixed gear set between the locking bar and the locking block 7, the locking block 7 can be locked at any position of the locking bar, so that the stepless adjustment of the angle of the backrest 2 can be achieved.

[0057] The locking block 7 is provided with a clamping groove 11 so that the locking block 7 has a U-shaped structure, and the locking block 7 is pushed toward the side wall of the locking groove by the inclined pushing surface 13, so that the side wall of the locking block 7 is fitted and locked with the side wall of the locking groove, thereby fixing the backrest 2. When the side wall of the locking block 7 is fitted and locked with the side wall of the locking groove, the convex teeth 15 on the locking block 7 are engaged and locked with the locking rack 14 on the side wall of the locking groove, thereby improving the locking effect and thus improving the stability of the angle fixation of the backrest 2. A tension spring 18 is used to connect the connecting piece 19 and the rear end of the armrest 4. When the user adjusts the angle of the backrest 2 to increase, he / she presses against the backrest 2 to adjust it backwards. The tension spring 18 plays a role of resistance protection, so that the backrest 2 is slowly adjusted to the maximum angle. When the user adjusts the large angle of the backrest 2 to a small angle, the lock buckle 8 is turned to disengage the push head 12 from the clamping groove 11, and the convex tooth 15 disengages the locking rack 14. The backrest 2 automatically returns to the state of the small angle with the help of the tension spring 18. By using the tension spring 18 structure, the inconvenience of the traditional seat armrest 4 adjustment structure requiring force to lift and pull the armrest 4 is solved. The stepless adjustment chair of the backrest 2 of this patent application can realize stepless adjustment of the angle of the seat backrest 2, which is convenient for users to choose a comfortable angle of the backrest 2 and has a good user experience.

[0058] 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 chair with a stepless backrest adjustment, comprising a seat and a backrest connected together by rotation, the seat being connected to the legs, and the backrest being connected to the armrests, characterized in that: A stepless adjustment mechanism is provided between the armrest and the support leg, and the stepless adjustment mechanism includes: Locking strip; Locking block; The lock buckle can drive the locking block to move toward the locking strip and make the locking block fit and lock with the locking strip.

2. The chair with a stepless backrest adjustment according to claim 1, characterized in that: A slide groove is arranged on the locking strip, a slide column is connected to the supporting leg, and the end of the slide column is movably inserted in the slide groove for sliding.

3. The chair with a stepless backrest adjustment according to claim 1, characterized in that: A locking groove is arranged on the locking strip, a clamping groove is arranged on the locking block, a pushing head is arranged on the lock buckle, and the two side surfaces of the pushing head are inclined to form a pushing surface. The pushing head moves so that the pushing surface abuts against the side walls of the clamping groove to push the two sides of the locking block toward the locking groove, thereby making the side walls of the locking block fit and lock with the side walls of the locking groove.

4. The chair with a stepless backrest adjustment according to claim 3, characterized in that: A locking rack is arranged on the side wall of the locking groove, and a convex tooth is arranged on the locking block, and the convex tooth is engaged and locked with the locking rack.

5. The chair with a stepless backrest adjustment according to claim 3, characterized in that: The lock buckle is rotatably installed in the clamping groove.

6. The chair with a stepless backrest adjustment according to claim 1, characterized in that: A tension spring is connected between the rear of the armrest and the support foot.

7. The chair with a stepless backrest adjustment according to claim 1, characterized in that: The locking strip comprises a left adjusting member and a right adjusting member which are arranged opposite to each other, a locking block is arranged between the left adjusting member and the right adjusting member, the opposite surfaces of the left adjusting member and the right adjusting member are locking surfaces, and the locking block is fitted and locked with the locking surfaces.

8. A chair with a stepless backrest adjustment according to any one of claims 1 to 7, characterized in that: A connecting piece is arranged on the upper end of the supporting leg, a locking block is arranged on the connecting piece, and a locking strip is arranged on the armrest.

9. The chair with a stepless backrest adjustment according to claim 8, characterized in that: The connecting member includes a fixed seat and a rotating seat, the rotating seat is rotatably installed on the fixed seat, and the locking block is arranged on the fixed seat; the supporting foot includes a front foot and a rear foot, the upper end of the front foot is plug-connected with the rotating seat, and the upper end of the rear foot is plug-connected with the fixed seat.

10. The chair with a stepless backrest adjustment according to claim 1, characterized in that: End caps are connected to both ends of the armrest, and the rear of the armrest is rotatably connected to the side of the backrest.

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