A split-back structure for a chair

Abstract

This application discloses a split-type chair back structure, including a chair back body, a backrest frame disposed on the front side of the chair back body, and a lumbar support frame disposed below the backrest frame. The backrest frame is provided with a first connecting part, and the lumbar support frame is detachably connected to the front side of the first connecting part. The chair back body includes a crossbeam, a second connecting part, an extension, and a locking part. The second connecting part is disposed in the middle of the crossbeam and is detachably connected to the rear side of the first connecting part. The extension extends upward from both ends of the crossbeam, and the ends of the extensions are provided with locking parts. The backrest frame has first slots on both sides that engage with the locking parts, and the extension fits snugly against the backrest frame. This allows for the individual replacement of damaged parts, avoiding overall replacement and reducing replacement costs, and also prevents stress concentration on the backrest frame when under load, reducing the risk of structural loosening.

Description

Technical Field

[0001] This application relates to the field of chair technology, specifically to a split backrest structure for a chair. Background Technology

[0002] Traditional chairs typically use a one-piece curved back design, with the lower part of the backrest connected to the seat via a connecting structure. When leaning against the seat, the load-bearing capacity at the connection point is too high, making it prone to damage. Once damaged, the entire backrest needs to be disassembled and replaced, resulting in high replacement costs.

[0003] Currently, some chairs use support columns and mounting hardware to install backrests. However, since the support columns are vertically positioned in the middle of the backrest and connected to the lower part of the backrest, the sides of the backrest are not supported. If the user leans against the backrest and sways from side to side, the force on the backrest will be uneven, and the backrest will easily become loose. In addition, connecting the support columns and the backrest with mounting hardware makes the assembly of the chair back more complicated. Utility Model Content

[0004] Therefore, this application provides a split backrest structure for a chair to solve the technical problems of high replacement cost and easy loosening of the backrest in the prior art.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] A split-type chair back structure includes a chair back body, a backrest frame disposed on the front side of the chair back body, and a lumbar support frame disposed below the backrest frame. The backrest frame is provided with a first connecting part, and the lumbar support frame is detachably connected to the front side of the first connecting part.

[0007] The chair back body includes a crossbeam, a second connecting part, an extension part, and a snap-fit ​​part. The second connecting part is located in the middle of the crossbeam and is detachably connected to the rear side of the first connecting part. The extension part is located at both ends of the crossbeam and extends upward. The end of the extension part is provided with a snap-fit ​​part. The two sides of the backrest frame are provided with first slots that snap into the snap-fit ​​parts. The extension part is fitted to the backrest frame.

[0008] Optionally, the backrest is provided with a protrusion on the rear side. The protrusion includes an arc-shaped protruding surface and a first mounting hole protruding from the protruding surface. The first connecting part is provided with a receiving groove corresponding to the protrusion. A limiting hole is provided in the receiving groove. The first mounting hole is inserted into the limiting hole. The groove surface of the receiving groove is in contact with the protruding surface.

[0009] Optionally, the lumbar support includes a third connecting part disposed below the protrusion and corresponding to the first connecting part, a spring is provided between the third connecting part and the first connecting part, and there is a space for movement between the lower part of the lumbar support and the backrest body.

[0010] Optionally, a second slot is provided on the front side of the second connecting part, and the second slot engages with the first connecting part.

[0011] Optionally, the first connecting part is provided with a second mounting hole, and the second connecting part is provided with a third mounting hole corresponding to the second mounting hole. The first connecting part and the second connecting part are fixed by screws passing through the second mounting hole and the third mounting hole.

[0012] Alternatively, the chair back body may further include an identification element, which is detachably disposed on the rear side of the second connecting portion and covers the third mounting hole.

[0013] Optionally, the split-type chair back structure further includes a headrest component, which includes a lifting assembly, a connecting frame, and a headrest frame. One end of the connecting frame is rotatably connected to one end of the lifting assembly, and the other end of the connecting frame is rotatably connected to the headrest frame. The lifting assembly is detachably connected to the upper part of the backrest frame.

[0014] Further optionally, the lifting assembly includes a headrest connecting block, a longitudinal rod, and a transverse rod. The front side of the headrest connecting block is detachably connected to the upper part of the backrest frame. The transverse rod is fixedly disposed on the rear side of the headrest connecting block. A channel for accommodating the longitudinal rod is formed between the transverse rod and the headrest connecting block. The longitudinal rod passes through the channel and is slidably connected vertically to the rear side of the headrest connecting block.

[0015] Compared with the prior art, this application has at least the following beneficial effects:

[0016] Firstly, the front of the first connecting part of the lumbar support frame and the backrest frame are detachably connected, and the rear of the second connecting part of the backrest body is detachably connected. The modular and detachable design of the split backrest structure allows for the individual replacement of damaged parts, avoiding the need for overall replacement and reducing replacement costs. Secondly, the second connecting part is located in the middle of the crossbeam, with both ends of the crossbeam extending upwards to form extensions. The ends of the extensions are provided with snap-fit ​​parts, and the sides of the backrest frame are provided with first slots that snap into the snap-fit ​​parts. The extensions fit snugly against the backrest frame, so that the sides of the backrest frame are supported by the extensions, and the middle of the backrest frame is supported by the second connecting part, preventing stress concentration when the backrest frame is under force and reducing the risk of structural loosening. Attached Figure Description

[0017] To more intuitively illustrate the prior art and this application, exemplary drawings are provided below. It should be understood that the specific shapes and structures shown in the drawings should not generally be regarded as limiting conditions for implementing this application; for example, based on the technical concept disclosed in this application and the exemplary drawings, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, size ratios, etc. of certain units (components).

[0018] Figure 1 A first view schematic diagram of a split backrest structure of a chair provided in an embodiment of this application;

[0019] Figure 2 A second view schematic diagram of a split backrest structure of a chair provided in an embodiment of this application;

[0020] Figure 3 A partial exploded view from a first perspective of a split backrest structure of a chair provided in an embodiment of this application;

[0021] Figure 4 A partial exploded view from a second perspective of a split backrest structure of a chair provided in an embodiment of this application;

[0022] Figure 5 An exploded view of a headrest component of a split-type chair back structure provided in an embodiment of this application;

[0023] Figure 6 This is a diagram illustrating the usage state of a split-type chair back structure provided in an embodiment of this application.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1. Chair back body; 11. Crossbeam; 12. Second connecting part; 121. Second slot; 122. Third mounting hole; 13. Extension part; 14. Snap-fit ​​part; 15. Mounting part; 2. Backrest frame; 21. First connecting part; 211. Receiving groove; 212. Second mounting hole; 213. Fixing post; 22. First slot; 3. Lumbar support frame; 31. Protrusion; 311. First mounting hole part; 312. Protruding surface; 3 2. Third connecting part; 321. Third slot; 4. Spring component; 5. Identification component; 6. Headrest component; 61. Lifting assembly; 611. Headrest connecting block; 612. Longitudinal rod; 613. Transverse rod; 614. Spring ball; 615. Channel; 616. Slide groove; 617. Slide track; 62. Connecting frame; 63. Headrest frame; 64. Connecting assembly; 641. First connecting piece; 642. Second connecting piece; 7. Seat. Detailed Implementation

[0026] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Example 1

[0028] refer to Figure 1-4 and Figure 6 As shown, Embodiment 1 provides a split backrest structure for a chair, including a backrest body 1, a backrest frame 2, and a lumbar support frame 3. The backrest frame 2 and the lumbar support frame 3 are located on the front side of the backrest body 1, and the lumbar support frame 3 is located below the backrest frame 2.

[0029] Both the backrest frame 2 and the lumbar support frame 3 are rectangular frame structures formed by upper and lower crossbeams and left and right vertical beams. The backrest frame 2 has a first connecting part 21 on the rear side of the lower crossbeam, and the lumbar support frame 3 has an upper crossbeam that is detachably connected to the front side of the first connecting part 21. Specifically, the lumbar support frame 3 has two symmetrically arranged protrusions 31 on the rear side of the upper crossbeam. Each protrusion 31 includes an arc-shaped protrusion surface 312 and a first mounting hole 311 protruding from the protrusion surface 312. The first connecting part 21 has a receiving groove 211 corresponding to each of the two protrusions 31. The receiving groove 211 has a limiting hole. The first mounting hole 311 is inserted into the limiting hole, and a flange screw is inserted into the first mounting hole 311 to fix the protrusion 31 to the first connecting part 21, thereby fixing the lumbar support frame 3 below the backrest frame 2. The groove surface of the receiving groove 211 is attached to the protruding surface 312. In this way, by increasing the arc-shaped contact surface between the protruding part 31 and the receiving groove 211, external forces (such as the pressure borne by the lumbar support) can be converted into tangential forces along the curved surface, reducing the direct shear force at the connection and thus reducing structural deformation or damage caused by overload.

[0030] The chair back body 1 includes a crossbeam 11, a second connecting part 12, an extension 13, a snap-fit ​​part 14, and a mounting part 15. The second connecting part 12 is located in the middle of the crossbeam 11 and is detachably connected to the rear side of the first connecting part 21. The extension 13 is located at both ends of the crossbeam 11 and extends upward. The end of the extension 13 is provided with a snap-fit ​​part 14. The two sides of the backrest frame 2 (i.e., the left and right vertical beams of the backrest frame 2) are provided with first slots 22 that snap into the snap-fit ​​parts 14. The extension 13 is fitted to the backrest frame 2. The two ends of the crossbeam 11 extend downward and converge towards the middle, connecting with the two ends of the mounting part 15. The mounting part 15 is used for mounting onto the chair body. The front side of the second connecting part 12 is provided with a second slot 121. When the snap-fit ​​part 14 snaps into the first slot 22, the second slot 121 snaps into the first connecting part 21, thereby achieving a quick connection between the chair back body 1 and the backrest frame 2 through snap-fit. In addition, the extension 13 fully fits into the backrest frame 2 to form a surface contact, preventing stress concentration when the backrest frame 2 is under force, so that both the left and right sides of the backrest frame 2 are supported, and the second slot 121 engages with the first connecting part 21, so that the lower part of the backrest frame 2 is supported on the second connecting part 12, thereby making the connection between the backrest frame 2 and the chair back body 1 more stable.

[0031] The first connecting part 21 is provided with a second mounting hole 212, and the second connecting part 12 is provided with a third mounting hole 122 corresponding to the second mounting hole 212. Screws are inserted into the second mounting hole 212 and the third mounting hole 122, and the first connecting part 21 and the second connecting part 12 are fixed together by the screws, so that the connection between the backrest frame 2 and the chair back body 1 is further stabilized.

[0032] The lumbar support frame 3 also includes a third connecting part 32 extending downward from the middle of the upper crossbeam. The third connecting part 32 is located below the protrusion 31 and is correspondingly arranged with the first connecting part 21. A spring member 4 is provided between the third connecting part 32 and the first connecting part 21. A third slot 321 is provided on the rear side of the third connecting part 32. A fixing post 213 corresponding to the third slot 321 is provided on the first connecting part 21. One end of the spring member 4 is placed in the third slot 321, and the other end is sleeved on the fixing post 213. Two spring members 4 are provided to provide elastic support for the lower part of the first connecting part 21 and the third connecting part 32. There is a space for movement between the lower part of the lumbar support frame 3 and the chair back body 1, that is, the lower part of the lumbar support frame 3 can swing at a certain angle. In the prior art, in order to make the lumbar support more comfortable to use, a space for movement is usually left between the lower part of the lumbar support and the chair back body, which makes the connection between the lumbar support and the chair back body easy to loosen. In this application, by further adding the spring member 4 to support the third connecting part 32, the lumbar support frame 3 forms a multi-point support with staggered vertical spacing, which not only preserves the comfort of the lumbar support, but also makes the connection between the lumbar support frame 3 and the back support frame 2 more stable.

[0033] The chair back body 1 also includes an identification element 5, which is detachably mounted on the rear side of the second connecting part 12 and covers the third mounting hole 122. Specifically, a groove for accommodating the identification element 5 is provided on the rear side of the second connecting part 12, and a through hole is provided around the groove. The identification element 5 is snapped into the through hole. The identification element 5 is made of rubber, and an identification mark can be engraved on the outer side of the identification element 5. It also covers the screw in the third mounting hole 122 for decorative purposes.

[0034] The assembly process of the split-type chair back structure of this application is as follows: S1, install the spring 4 between the third connecting part 32 and the first connecting part 21, that is, one end of the spring 4 is placed in the third slot 321 and the other end is sleeved on the fixing part; S2, place the protrusion 31 in the receiving groove 211, insert the first mounting hole 311 into the limiting hole, and use the flange screw to insert into the first mounting hole 311 and tighten it to fix the backrest frame 2 and the lumbar support frame 3 together; S3, install the snap-fit ​​part 14 onto the first slot 22, press down on the second connecting part 12, so that the first connecting part 21 snaps into the second slot 121, and complete the fixation between the chair back body 1 and the backrest frame 2; S4, on the rear side of the second body, fix the screw into the third mounting hole 122 and the second mounting hole 212 to further stabilize the connection between the chair back body 1 and the backrest frame 2.

[0035] Example 2

[0036] refer to Figure 1 , Figure 2 , Figure 5 , Figure 6 As shown, Embodiment 2 provides another split-back structure for a chair, which is basically the same as Embodiment 1. The similarities will not be repeated here. Only the differences will be introduced below.

[0037] The split-type chair back structure also includes a headrest component 6, which includes a lifting assembly 61, a connecting frame 62, and a headrest frame 63. One end of the connecting frame 62 is rotatably connected to one end of the lifting assembly 61 via a connecting assembly 64, and the other end of the connecting frame 62 is rotatably connected to the headrest frame 63 via another set of connecting assemblies 64, thereby facilitating the angle adjustment of the headrest frame 63 and making it convenient for the user. The connecting assembly 64 is a conventional structure, including a first connecting member 641 and a second connecting member 642. The opposing surfaces of the first connecting member 641 and the second connecting member 642 are friction surfaces or toothed meshing surfaces. The toothed meshing surfaces are provided with multiple rounded prism teeth, which are arranged radially and evenly distributed circumferentially. The first connecting member 641 and the second connecting member 642 are installed by meshing through the multiple rounded prism teeth structure. By applying torque to one of the connecting members, the first connecting member 641 and the second connecting member 642 undergo circumferential relative displacement (i.e., relative rotation), thereby achieving angle adjustment. For example, connecting components 64 are symmetrically arranged at both ends of the headrest frame 63. The end of the first connecting member 641 away from the toothed meshing surface is fixedly embedded in the connecting frame 62, and the end of the second connecting member 642 away from the toothed meshing surface is fixedly embedded in the headrest frame 63. The headrest frame 63 and the connecting frame 62 are connected together by screws, i.e., the screws pass through the first connecting member 641 and the second connecting member 642 along the central axis. When the headrest frame 63 is rotated, due to the connecting components 64, the headrest frame 63 can rotate relative to the connecting frame 62, facilitating the adjustment of the headrest frame 63's angle. Similarly, the lifting component 61 and the connecting frame 62 can also be connected through the connecting components 64, thereby enabling the connecting frame 62 to rotate relative to the lifting component 61 and adjusting the angle of the connecting frame 62. For example, a spring is inserted through the middle of the screw, and the connecting components 64 are symmetrically installed. The screw passes through the two connecting components 64 at one time. The two ends of the spring abut against the first connecting member 641 or the second connecting member 642 located on the inner side, so that the first connecting member 641 engages with the corresponding second connecting member 642, thereby achieving angle locking.

[0038] The lifting assembly 61 is detachably connected to the upper part of the backrest frame 2. Specifically, the lifting assembly 61 includes a headrest connecting block 611, a longitudinal rod 612, and a transverse rod 613. The front side of the headrest connecting block 611 is provided with a mounting groove, which is engaged with the upper crossbeam of the backrest frame 2. The transverse rod 613 is fixedly set on the rear side of the headrest connecting block 611. A channel 615 for accommodating the longitudinal rod 612 is formed between the transverse rod 613 and the headrest connecting block 611. Slide grooves 616 are symmetrically arranged on both sides of the channel 615. Slide tracks 617 adapted to the slide grooves 616 are provided on both sides of the longitudinal rod 612. A spring retaining ball 614 is provided on the rear side of the headrest connecting block 611. Multiple positioning holes for positioning the spring retaining ball 614 are provided on the front side of the longitudinal rod 612. When the longitudinal rod 612 moves up and down in the channel 615, the position of the longitudinal rod 612 is fixed by the cooperation of the spring retaining ball 614 and the positioning holes. It should be noted that the spring-loaded ball 614 structure is a common mechanical positioning device, mainly used for relative movement between two objects. Position locking is achieved through the engagement of the spring-loaded ball 614 with the positioning hole. Its typical structure consists of the following: the spring-loaded ball 614 includes a ball, a spring, and a housing. The housing is a metal sleeve with internal threads, and the inner cavity of the sleeve is designed with a stepped hole structure to accommodate the spring and constrain the ball's travel. Specifically, the spring pushes the ball part into the positioning hole, using radial constraint force to prevent relative movement between the headrest connecting block 611 and the longitudinal rod 612. When an upward pushing force or a downward pulling force is applied to the lower part of the longitudinal rod 612, the ball is pressed back into the housing, the spring is compressed, and the longitudinal rod 612 can slide. When the ball slides into the next hole, the spring is released, and the user will hear a "click" sound.

[0039] The mounting part 15 of the chair back body 1 is used to install the split chair back structure onto the seat 7 of the chair body. The mounting part 15 is provided with grooves at intervals to reduce the overall weight of the chair back structure.

[0040] The front sides of the backrest 2, the lumbar support 3, and the headrest 63 are all covered with mesh fabric. The mesh fabric is made of nylon and fiberglass, which not only provides sufficient support but also allows for better breathability.

[0041] The technical features of the above embodiments can be combined in any way (as long as there is no contradiction in the combination of these technical features). For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; these embodiments not explicitly written should also be considered to be within the scope of this specification.

Claims

1. A split-type backrest structure for a chair, characterized in that, The chair includes a backrest body (1), a backrest frame (2) disposed on the front side of the backrest body (1), and a lumbar support frame (3) disposed below the backrest frame (2). The backrest frame (2) is provided with a first connecting part (21), and the lumbar support frame (3) is detachably connected to the front side of the first connecting part (21). The chair back body (1) includes a crossbeam (11), a second connecting part (12), an extension part (13), and a snap-fit ​​part (14). The second connecting part (12) is located in the middle of the crossbeam (11) and is detachably connected to the rear side of the first connecting part (21). The extension part (13) is located at both ends of the crossbeam (11) and extends upward. The end of the extension part (13) is provided with a snap-fit ​​part (14). The backrest frame (2) has first slots (22) on both sides that snap into the snap-fit ​​part (14). The extension part (13) is fitted to the backrest frame (2).

2. The split-type backrest structure of a chair according to claim 1, characterized in that, The backrest (3) has a protrusion (31) on its rear side. The protrusion (31) includes an arc-shaped protrusion (312) and a first mounting hole (311) protruding from the protrusion (312). The first connecting part (21) has a receiving groove (211) corresponding to the protrusion (31). A limiting hole is provided in the receiving groove (211). The first mounting hole (311) is inserted into the limiting hole. The groove surface of the receiving groove (211) is in contact with the protrusion (312).

3. The split-type chair back structure according to claim 2, characterized in that, The lumbar support frame (3) includes a third connecting part (32) disposed below the protrusion (31) and corresponding to the first connecting part (21). A spring member (4) is provided between the third connecting part (32) and the first connecting part (21). There is a space for movement between the lower part of the lumbar support frame (3) and the chair back body (1).

4. The split-type backrest structure of a chair according to claim 1, characterized in that, The front side of the second connecting part (12) is provided with a second slot (121), which engages with the first connecting part (21).

5. The split-type chair back structure according to claim 4, characterized in that, The first connecting part (21) is provided with a second mounting hole (212), and the second connecting part (12) is provided with a third mounting hole (122) corresponding to the second mounting hole (212). The first connecting part (21) and the second connecting part (12) are fixed by screws passing through the second mounting hole (212) and the third mounting hole (122).

6. The split-type backrest structure of a chair according to claim 4, characterized in that, The chair back body (1) also includes an identification element (5), which is detachably disposed on the rear side of the second connecting part (12) and covers the third mounting hole (122).

7. The split-type backrest structure of a chair according to claim 1, characterized in that, The split-type chair back structure also includes a headrest component (6), which includes a lifting assembly (61), a connecting frame (62), and a headrest frame (63). One end of the connecting frame (62) is rotatably connected to one end of the lifting assembly (61), and the other end of the connecting frame (62) is rotatably connected to the headrest frame (63). The lifting assembly (61) is detachably connected to the upper part of the backrest frame (2).

8. The split-type chair back structure according to claim 7, characterized in that, The lifting assembly (61) includes a headrest connecting block (611), a longitudinal rod (612), and a transverse rod (613). The front side of the headrest connecting block (611) is detachably connected to the upper part of the backrest frame (2). The transverse rod (613) is fixedly installed on the rear side of the headrest connecting block (611). A channel (615) for accommodating the longitudinal rod (612) is formed between the transverse rod (613) and the headrest connecting block (611). The longitudinal rod (612) passes through the channel (615) and is slidably connected vertically to the rear side of the headrest connecting block (611).

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