Chair back adjusting structure applied to office chair

Abstract

A chair back adjusting structure applied to an office chair comprises a back support and a rubber back frame, the upper end of the rubber back frame is connected with the upper end of the back support in a matched mode, and the middle of the back support is connected with the middle of the rubber back frame through a back frame adjusting structure. The back frame adjusting structure comprises a rocker arm, a back frame part fixedly arranged on the back support and a back frame part fixedly arranged on the rubber back frame, and a driving rotating shaft rotationally connected to the back frame part and a linkage rotating shaft rotationally connected to the back frame part are arranged at the two ends of the rocker arm respectively; a forward moving limiting part and a backward moving limiting part are arranged on the back frame part, and the driving rotating shaft is connected with and controlled by an adjusting handle to rotate; and a fixed matching part is arranged on the adjusting handle. After the rubber back frame is adjusted to a required position, the fixed matching part can automatically abut against the corresponding limiting part under the elastic force action of the rubber back frame, the stable locking effect is achieved, the chair back can provide the stable waist jacking effect for a user, and potential safety hazards caused by accidental movement are prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of office chairs, in particular to a chair back adjustment structure used on office chairs. Background Art

[0002] In the modern office environment, office chairs are daily essential furniture, and their design is directly related to the physical health and comfort of office workers. In order to improve the comfort of office chairs, existing designs generally add a lumbar support device to the back of the chair, aiming to reduce the discomfort and fatigue caused by sitting for a long time through reasonable lumbar support. For example, the office chair disclosed in the technical solution of patent No. 202221391831.2, the back of the chair of this technical solution includes a rubber back frame and a back frame, both sides of the rubber back frame are first curved sections, and the two first curved sections can be arched forward after the mesh is installed, providing initial support for the user's waist. At the same time, the top waist film fixedly installed between the first curved sections further enhances the support for the mesh, ensuring the stability and effectiveness of the lumbar support. In addition, the back of the chair also realizes the adjustment function of the backrest angle through the design of the first rotation point and the second rotation point, so that the upper part of the rubber back frame tilts backward and the lower part arches forward, providing convenience for office workers when they rest.

[0003] However, although this technical solution has made certain progress in adjusting the chair back angle, there are still some shortcomings in actual application. For example, this technical solution does not include a structure to lock the chair back position, which may cause the chair back angle to change every time the user leans on the chair back, making it impossible to stably support the user's back. This instability not only affects the user experience of the office chair, but may also have an adverse effect on the user's sitting posture and lumbar health. Utility Model Content

[0004] In order to overcome the deficiencies of the prior art, the utility model provides a chair back adjustment structure for an office chair.

[0005] The technical solution adopted by the utility model to solve its technical problems is:

[0006] A chair back adjustment structure for an office chair, comprising a back support and a rubber back frame, wherein the upper end of the rubber back frame is cooperatively connected to the upper end of the back support, and characterized in that: the middle portion of the back support is connected to the middle portion of the rubber back frame via a back frame adjustment structure for adjusting the front-rear position of the lower end of the rubber back frame, the back frame adjustment structure comprising a rocker arm for driving the lower end of the rubber back frame to move back and forth, a back frame portion fixedly mounted on the back support, and a back frame portion fixedly mounted on the rubber back frame, wherein both ends of the rocker arm are respectively provided with an active rotating shaft rotatably connected to the back frame portion and a linkage rotating shaft rotatably connected to the back frame portion;

[0007] The back frame is provided with a forward limiter and a backward limiter, and the active shaft is connected to the adjustment handle to control the rotation;

[0008] The adjustment handle is provided with a fixed fitting portion that is movable between the forward limit portion and the backward limit portion. The fixed fitting portion is configured to lock the forward position of the lower end of the rubber back frame when it is pressed against the forward limit portion under the elastic force of the rubber back frame, and to lock the backward position of the lower end of the rubber back frame when it is pressed against the forward limit portion under the elastic force of the rubber back frame.

[0009] In the present invention, there are two back frame adjustment structures and they are designed to be bilaterally symmetrical.

[0010] In the present invention, a back frame shaft hole is provided on the back frame part, the active shaft is rotatably installed in the back frame shaft hole, a rotation avoidance hole is provided in the back frame shaft hole, and the forward limit part and the backward limit part are arranged in the rotation avoidance hole.

[0011] In the present utility model, the adjustment handle includes a handle body fixedly connected to the active rotating shaft and a handle operating part connected to the handle body. The handle body is axially provided with a handle shaft portion that can be rotatably fitted in the rotation avoidance hole, and the fixed fitting portion is provided on the part of the handle shaft portion located in the rotation avoidance hole.

[0012] In the utility model, a coaxial matching hole is provided on the handle shaft, and a linkage positioning surface and / or a plurality of linkage positioning portions distributed circumferentially along the coaxial matching hole are raised on the hole wall of the coaxial matching hole; the end of the active rotating shaft away from the rocker arm is matched in the coaxial matching hole, and a linkage matching surface for matching the linkage positioning surface and / or a linkage matching groove for the linkage positioning portion to be embedded in the matching positioning is provided on the end of the active rotating shaft away from the rocker arm.

[0013] In the present invention, the rubber back frame includes two left-right symmetrical back frame arms, an upper back frame support whose two ends are respectively connected to the upper ends of the two back frame arms, and a lower back frame support whose two ends are respectively connected to the lower ends of the two back frame arms. The upper back frame support is connected to the upper end of the back bracket, and the back frame part is fixedly arranged on the middle rear side of the back frame arm.

[0014] In the present invention, the bottom of the back frame upper support is provided with a plurality of plug-in parts arranged from left to right, and the back bracket is provided with a plurality of plug-in slots arranged from left to right. Each of the plug-in parts is plug-fitted into an plug-in slot and fixedly connected to the back bracket by a first bolt.

[0015] In the present invention, the lumbar support parts of the two back frame arms are commonly connected to a lumbar support device, which includes a lumbar support bracket and a lumbar support component symmetrically arranged on the lumbar support bracket. The left and right ends of the lumbar support bracket can be installed on the two lumbar support parts movably up and down, and the position of the lumbar support component on the lumbar support bracket can be adjusted left and right.

[0016] In the present invention, the lumbar support bracket is provided with two left and right adjustment long holes for the lumbar support component to move left and right, and each left and right adjustment long hole is correspondingly installed with a lumbar support component.

[0017] In the present invention, the lumbar support assembly includes a lumbar support movable seat sliding on the front side of the lumbar support bracket, a lumbar support matching seat sliding on the rear side of the lumbar support bracket and a lumbar support cushion fixed to the front end of the lumbar support movable seat. The rear end of the lumbar support movable seat is provided with a movable vertical axis, and the front end of the lumbar support matching seat is fixed with a lumbar support buckle part that passes through the left and right adjustment long holes and is connected to the movable vertical axis buckle.

[0018] The beneficial effects of the present invention are as follows: the present invention controls the rocker arm linkage rubber back frame through the adjustment handle, so that the user can easily control the forward or backward movement of the lower part of the rubber back frame and the lumbar support device. When the adjustment handle is rotated in the first or second direction, the fixed matching part will rotate accordingly and abut against the corresponding limit part. The entire adjustment process is smooth and intuitive, which significantly improves the convenience of user operation. Moreover, by utilizing the elastic deformation characteristics of the rubber back frame itself, after adjusting to the desired position, the fixed matching part will automatically abut against the corresponding limit part under the elastic force of the rubber back frame, achieving a stable locking effect, which can enable the chair back to provide a stable lumbar support effect for the user. This design not only avoids the tedious manual locking of the user, but also improves the stability of the seat during use and prevents safety hazards caused by accidental movement. Therefore, the present invention has the advantages of good adjustment convenience, strong stability, simple structure, etc., which can enhance the user's experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further described below with reference to the accompanying drawings and embodiments:

[0020] Figure 1 Three-dimensional seat back adjustment structure Figure 1 ;

[0021] Figure 2 This is an exploded view of the seat back adjustment structure;

[0022] Figure 3 This is an exploded view of the back frame adjustment structure;

[0023] Figure 4 This is a schematic diagram of the installation of the back frame adjustment structure;

[0024] Figure 5A schematic diagram of the positions of the forward limit portion, the backward limit portion and the fixed matching portion;

[0025] Figure 6 A schematic diagram of the end of the active shaft being fitted into the coaxial fitting hole;

[0026] Figure 7 Three-dimensional seat back adjustment structure Figure 2 ;

[0027] Figure 8 This is a schematic diagram of the installation of the lumbar support device;

[0028] Figure 9 A comparison chart of the adjustment changes of the waist and back frame. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention.

[0030] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial...), then the directional indications are only used to explain the relative position relationship, movement status, etc. between the various components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0031] In addition, if there are descriptions involving "first" or "second" in the embodiments of the present invention, the descriptions of "first" or "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features specified as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0032] Reference Figure 1-9, a chair back adjustment structure used in an office chair, includes a back bracket 1 and a rubber back frame 2, the upper end of the rubber back frame 2 is cooperatively connected to the upper end of the back bracket 1, the middle part of the back bracket 1 is connected to the middle part of the rubber back frame 2 through a back frame adjustment structure for adjusting the front and rear position of the lower end of the rubber back frame 2, the back frame adjustment structure has two and is designed to be bilaterally symmetrical, the back frame adjustment structure includes a rocker arm 3 for driving the lower end of the rubber back frame 2 to move forward and backward, an integrally formed back frame part 100 fixed on the back bracket 1 and a back frame part 200 fixed on the rubber back frame 2 by a bolt connection method, the two ends of the rocker arm 3 are respectively integrally provided with an active rotating shaft 31 rotatably connected to the back frame part 100 and a linkage rotating shaft 32 rotatably connected to the back frame part 200, the linkage rotating shaft 32 is fixed in the linkage shaft hole of the back frame part 200 by a linkage bolt 500, and the axial direction of the active rotating shaft 31 and the axial direction of the linkage rotating shaft 32 are parallel to each other and staggered.

[0033] Furthermore, the back frame 100 is provided with a forward limit portion 101 and a backward limit portion 102, and the active shaft 31 is connected to and controlled by an adjustment handle 4 for rotation. The adjustment handle 4 is configured to drive the rocker arm 3 to rotate and swing around the active shaft 31 as the rotation center by controlling the rotation of the active shaft 31.

[0034] Furthermore, the adjustment handle 4 is provided with a fixed fitting portion 41 that is movable between the forward limit portion 101 and the rearward limit portion 102. The fixed fitting portion 41 is configured to lock the forward position of the lower end of the rubber backing frame 2 when it is pressed against the forward limit portion 101 under the elastic force of the rubber backing frame 2, and to lock the rearward position of the lower end of the rubber backing frame 2 when it is pressed against the forward limit portion 101 under the elastic force of the rubber backing frame 2.

[0035] When the lower portion of the rubber backing frame 2 and the lumbar support device 5 need to move forward, the active shaft 31 is controlled to rotate in a first direction by adjusting the handle 4 until the fixed fitting portion 41 abuts against the forward limit portion 101 as the active shaft 31 rotates. The travel limit portion, under the force generated by the elastic deformation of the rubber backing frame 2, remains in a state of abutting against the forward limit portion 101, thereby locking the rubber backing frame 2 in the forward position. When the lower portion of the rubber backing frame 2 and the lumbar support device 5 need to move backward, the active shaft 31 is controlled to rotate in a second direction by adjusting the handle 4 until the fixed fitting portion 41 abuts against the backward limit portion 102 as the active shaft 31 rotates. The travel limit portion, under the force generated by the elastic deformation of the rubber backing frame 2, remains in a state of abutting against the backward limit portion 102, thereby locking the rubber backing frame 2 in the backward position. The first direction is opposite to the second direction.

[0036] As a preferred embodiment, a back frame shaft hole 103 is provided on the back frame portion 100, and the active rotating shaft 31 is rotatably installed in the back frame shaft hole 103. A rotation avoidance hole 104 is provided in the back frame shaft hole 103, and the forward limit portion 101 and the backward limit portion 102 are arranged in the rotation avoidance hole 104; specifically, a back frame fan-shaped convex portion 1031 is protruded in the back frame shaft hole 103, and the forward limit portion 101 and the backward limit portion 102 are respectively the two ends of the back frame fan-shaped convex portion 1031.

[0037] As a preferred embodiment, the adjustment handle 4 includes a handle body 42 fixedly connected to the active rotating shaft 31 by a handle bolt 40 and a handle operating part 43 integrally connected to the handle body 42. The handle body 42 is axially provided with a handle shaft 421 that can be rotatably engaged in the rotation avoidance hole 104. The active rotating shaft 31 is coaxially arranged with the handle shaft 421. The fixed engaging part 41 is provided on the part of the handle shaft 421 located in the rotation avoidance hole 104, and the cross-sectional shape of the fixed engaging part 41 is fan-shaped.

[0038] As a preferred embodiment, a coaxial mating hole 422 is provided on the handle shaft 421, and a linkage positioning surface 423 and a plurality of linkage positioning portions 424 distributed circumferentially along the coaxial mating hole 422 are raised on the hole wall of the coaxial mating hole 422; the end of the active rotating shaft 31 away from the rocker arm 3 is fitted in the coaxial mating hole 422, and a linkage mating surface 311 for fitting with the linkage positioning surface 423 and a linkage mating groove 312 for the linkage positioning portion 424 to be embedded in the mating positioning is provided on the end of the active rotating shaft 31 away from the rocker arm 3, so that the adjustment handle 4 can stably and effectively control the rotation of the active rotating shaft 31 through the fitting positioning of the linkage positioning surface 423 and the linkage mating surface 311 and the insertion positioning of the linkage positioning portion 424 and the linkage mating groove 312.

[0039] As a preferred embodiment, the rubber back frame 2 includes two left-right symmetrical back frame arms 21, an upper back frame support 22 whose two ends are respectively connected to the upper ends of the two back frame arms 21, and a lower back frame support 23 whose two ends are respectively connected to the lower ends of the two back frame arms 21. The upper back frame support 22 is connected to the upper end of the back bracket 1, and a headrest bracket 300 is provided on the upper back frame support 22. A headrest device 400 is installed on the headrest bracket 300 for supporting the user's head; the back frame portion 200 is fixedly arranged on the rear side of the middle part of the back frame arm 21, and the middle part of the back frame arm 21 is bent forward and convex to form a lumbar support portion 211, so that after the mesh is installed on the rubber back frame 2, the mesh is arched forward by the action of the lumbar support portion 211, providing initial support for the user's waist.

[0040] As a preferred embodiment, the bottom of the back frame upper support 22 is provided with a plurality of plug-in portions 221 arranged from left to right, and the back bracket 1 is provided with a plurality of plug-in slots 105 arranged from left to right. Each of the plug-in portions 221 is plugged into an plug-in slot 105 and is fixedly connected to the back bracket 1 with a first bolt, so that the upper end of the rubber back frame 2 and the upper end of the back bracket 1 are combined and connected together.

[0041] As a preferred embodiment, the lumbar support parts 211 of the two back frame arms 21 are commonly connected to the lumbar support device 5, which further enhances the supporting effect on the mesh cloth, ensuring the stability and effectiveness of the lumbar support; further, the lumbar support device 5 includes a lumbar support bracket 51 and a lumbar support component 52 symmetrically arranged on the lumbar support bracket 51, and the left and right ends of the lumbar support bracket 51 can be mounted on the two lumbar support parts 211 movably up and down, and the position of the lumbar support component 52 on the lumbar support bracket 51 can be adjusted left and right to facilitate the adjustment of the position of the lumbar support device 5 supporting the user's waist, providing the user with a better waist support effect.

[0042] In this embodiment, the lumbar support bracket 51 is provided with two left and right adjustment long holes 511 for the lumbar support component 52 to move left and right. Each left and right adjustment long hole 511 corresponds to a lumbar support component 52. The lumbar support component 52 includes a lumbar support moving seat 521 sliding on the front side of the lumbar support bracket 51, a lumbar support matching seat 522 sliding on the rear side of the lumbar support bracket 51, and a lumbar support cushion 523 fixed to the front end of the lumbar support moving seat 521. The rear end of the lumbar support moving seat 521 is provided with a moving vertical shaft 5211, and the front end of the lumbar support matching seat 522 is fixed with a vertical shaft passing through the left and right adjustment long holes 511. 11 is a lumbar support buckle portion 5221 that is buckled with the movable vertical axis 5211, and the lumbar support matching seat 522 can rotate and swing relative to the lumbar support movable seat 521 with the movable vertical axis 5211 as the center. The lumbar support matching seat 522 and the lumbar support movable seat 521 are both elastic and tough, so that the lumbar support matching seat 522 and the lumbar support movable seat 521 can be elastically deformed according to the different positions of the matching lumbar support bracket 51, so that the rear sides of the lumbar support movable seat 521 and the rear sides of the lumbar support matching seat 522 can be better elastically fitted on the lumbar support bracket 51, and are not easy to move left and right.

[0043] The lumbar support bracket 51 is provided with a lumbar support moving part 512 at both ends. The lumbar support supporting part 211 is provided with an upper and lower guide grooves 212. The left and right lumbar support moving parts 512 are respectively slidably fitted in the upper and lower guide grooves 212 of the two lumbar support supporting parts 211. The lumbar support supporting part 211 is provided with a lumbar support mounting cover 24 for limiting the lumbar support part 211 in the upper and lower guide grooves 212. The rear side of the lumbar support mounting cover 24 is provided with a plurality of height gear grooves 241 distributed from top to bottom. The lumbar support moving part 512 is provided with a height elastic clip 25 that can elastically fit into any height gear groove 241 to limit the height of the lumbar support bracket 51. In the process of pushing the lumbar support bracket 51 up and down with force, the height elastic clip 25 can continuously move in and out of different height gear grooves 241 until the lumbar support bracket 51 is no longer pushed and the height elastic clip 25 no longer withdraws from the height gear groove 241, thereby locking the current height of the lumbar support bracket 51.

[0044] The above description is only a preferred embodiment of the present invention. Any technical solution that achieves the purpose of the present invention by substantially the same means shall fall within the scope of protection of the present invention.

Claims

1. A backrest adjustment structure for an office chair, comprising a back support (1) and a rubber back frame (2), wherein the upper end of the rubber back frame (2) is cooperatively connected to the upper end of the back support (1), and is characterized in that: The middle part of the back support (1) is connected to the middle part of the adhesive back frame (2) via a back frame adjustment structure for adjusting the front-back position of the lower end of the adhesive back frame (2), the back frame adjustment structure comprising a rocker arm (3) for driving the lower end of the adhesive back frame (2) to move back and forth, a back frame portion (100) fixedly mounted on the back support (1), and a back frame portion (200) fixedly mounted on the adhesive back frame (2), and two ends of the rocker arm (3) are respectively provided with a driving shaft (31) rotatably connected to the back frame portion (100) and a linkage shaft (32) rotatably connected to the back frame portion (200); The back frame portion (100) is provided with a forward limit portion (101) and a backward limit portion (102), and the active rotating shaft (31) is connected to the adjusting handle (4) to control rotation; The adjusting handle (4) is provided with a fixed fitting portion (41) movable between the forward limit portion (101) and the backward limit portion (102), and the fixed fitting portion (41) is configured to lock the forward position of the lower end of the rubber back frame (2) when pressed against the forward limit portion (101) under the elastic force of the rubber back frame (2), and to lock the backward position of the lower end of the rubber back frame (2) when pressed against the forward limit portion (101) under the elastic force of the rubber back frame (2).

2. The backrest adjustment structure for an office chair according to claim 1, characterized in that: There are two back frame adjustment structures and they are designed to be bilaterally symmetrical.

3. The backrest adjustment structure for an office chair according to claim 1 or 2, characterized in that: The back frame portion (100) is provided with a back frame shaft hole (103), the active rotating shaft (31) is rotatably installed in the back frame shaft hole (103), a rotation avoidance hole (104) is provided in the back frame shaft hole (103), and the forward limit portion (101) and the backward limit portion (102) are arranged in the rotation avoidance hole (104).

4. The backrest adjustment structure for an office chair according to claim 3, characterized in that: The regulating handle (4) comprises a handle body (42) fixedly connected to the active rotating shaft (31) and a handle operating portion (43) connected to the handle body (42); the handle body (42) is provided with a handle shaft portion (421) rotatably engaged in the rotation avoidance hole (104) along the axial direction; and the fixed engaging portion (41) is provided on the portion of the handle shaft portion (421) located in the rotation avoidance hole (104).

5. The backrest adjustment structure for an office chair according to claim 4, characterized in that: The handle shaft (421) is provided with a coaxial matching hole (422), and a linkage positioning surface (423) and / or a plurality of linkage positioning portions (424) distributed circumferentially along the coaxial matching hole (422) are protruded on the hole wall of the coaxial matching hole (422); the end of the active rotating shaft (31) away from the rocker arm (3) is matched in the coaxial matching hole (422), and the end of the active rotating shaft (31) away from the rocker arm (3) is provided with a linkage matching surface (311) for matching with the linkage positioning surface (423) and / or a linkage matching groove (312) for the linkage positioning portion (424) to be embedded and positioned for matching.

6. The backrest adjustment structure for an office chair according to claim 1 or 2, characterized in that: The adhesive back frame (2) comprises two left-right symmetrical back frame arms (21), an upper back frame support (22) whose two ends are respectively connected to the upper ends of the two back frame arms (21), and a lower back frame support (23) whose two ends are respectively connected to the lower ends of the two back frame arms (21), wherein the upper back frame support (22) is connected to the upper end of the back bracket (1), and the back frame portion (200) is fixedly arranged on the middle rear side of the back frame arm (21).

7. The backrest adjustment structure for an office chair according to claim 6, characterized in that: The bottom of the back frame upper support (22) is provided with a plurality of insertion portions (221) arranged from left to right, and the back bracket (1) is provided with a plurality of insertion slots (105) arranged from left to right, each of the insertion portions (221) is inserted and fitted into an insertion slot (105) and fixedly connected to the back bracket (1) using a first bolt.

8. The backrest adjustment structure for an office chair according to claim 6, characterized in that: The lumbar support parts (211) of the two back frame arms (21) are commonly connected to a lumbar support device (5), the lumbar support device (5) comprising a lumbar support bracket (51) and a lumbar support component (52) symmetrically arranged on the lumbar support bracket (51), the left and right ends of the lumbar support bracket (51) being movably mounted on the two lumbar support parts (211), and the position of the lumbar support component (52) on the lumbar support bracket (51) being adjustable left and right.

9. The backrest adjustment structure for an office chair according to claim 8, characterized in that: The lumbar support bracket (51) is provided with two left and right adjustment slots (511) for the lumbar support assembly (52) to move left and right, and each left and right adjustment slot (511) is correspondingly mounted with a lumbar support assembly (52).

10. The backrest adjustment structure for an office chair according to claim 9, characterized in that: The lumbar support assembly (52) comprises a lumbar support movable seat (521) sliding on the front side of the lumbar support bracket (51), a lumbar support matching seat (522) sliding on the rear side of the lumbar support bracket (51), and a lumbar support cushion (523) fixed to the front end of the lumbar support movable seat (521). The rear end of the lumbar support movable seat (521) is provided with a movable vertical shaft (5211), and the front end of the lumbar support matching seat (522) is fixed with a lumbar support buckle portion (5221) that passes through the left and right adjustment long holes (511) and is buckled with the movable vertical shaft (5211).

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