Seat-back linkage structure applied to chair

Abstract

A seat-back linkage structure applied to a chair comprises a main frame, a back support and a seat support, and the main frame comprises a front support and a rear support; the back support comprises a back frame body, an elastic bent arm and a linkage extending part located above the elastic bent arm, the elastic bent arm comprises a rear elastic arm extending forwards and downwards from the bottom end of the back frame body and a front elastic arm extending forwards and upwards from the bottom end of the rear elastic arm, and a fulcrum component in flexible connection with the back support is arranged on the rear support. The fulcrum component movably abuts against the bottom end of the back frame body and the rear side of the rear elastic arm; the rear end of the linkage extending part is connected to the back frame body, a movable seat connected with the front end of the front elastic arm is arranged at the front end of the linkage extending part in a protruding mode, and the movable seat is flexibly connected with the front support and can move up and down relative to the front support; and the seat bracket is rigidly connected to the movable seat. The back support can be correspondingly adjusted according to the back curve and the motion range of the user, the self-adaptive capacity of the chair is remarkably improved, and more comfortable sitting posture experience is provided for the user.

Description

Technical Field

[0001] The utility model relates to the technical field of chairs, and particularly relates to a seat-back linkage structure applied to a chair. Background Art

[0002] In modern society, as an indispensable piece of furniture in work and life, the optimization of the design and function of chairs is directly related to the comfort and health of users.

[0003] In the current market, most chairs have achieved the function of reclining and rotating adjustment of the backrest, and some high-end models are even equipped with a locking device, allowing users to lock the backrest at any adjusted angle to meet different work or rest needs. However, such backrest designs have exposed the following defects in practical applications:

[0004] 1. Once the backrest is locked, its position remains fixed. When the human body leans backward in a natural state, the backrest cannot adjust accordingly according to the back curve and movement amplitude of the user, resulting in the user feeling a rigid reaction force, unable to effectively disperse the pressure, affecting the overall comfort experience. This design ignores the dynamic changes of the human sitting posture and lacks the necessary adaptive ability;

[0005] 2. Due to the static characteristics of the backrest after being locked, it cannot provide precise support according to the changes in the back position and posture of the user. This not only limits the degree of fit of the chair to the natural curve of the spine but may also cause fatigue and injury to the back muscles and joints during long-term use, reducing the practicality of the chair;

[0006] 3. For users who need to take a short break or change their sitting postures, the traditional design of the locked backrest limits their ability to lean backward naturally. In order to obtain better back support, users often have to slide their hips forward, and may even lose balance and slide out of the seat, greatly affecting the convenience and safety of use. Content of the Utility Model

[0007] In order to overcome the deficiencies of the prior art, the utility model provides a seat-back linkage structure applied to a chair.

[0008] The technical solution adopted by the utility model to solve its technical problems is:

[0009] A seat-back linkage structure applied to a chair, comprising a main frame, a backrest support and a seat support. The main frame includes a front support and a rear support; the backrest support includes a backrest body, an elastic bent arm and a linkage extension part located above the elastic bent arm. The elastic bent arm includes a rear elastic arm extending forward and downward from the bottom end of the backrest body and a front elastic arm extending forward and upward from the bottom end of the rear elastic arm. The connection position of the rear elastic arm and the front elastic arm can be elastically bent and deformed;

[0010] A fulcrum member that is softly connected to the back support is provided on the rear support, and the fulcrum member is movably abutted against the bottom end of the back frame body and the rear side of the rear spring arm;

[0011] The rear end of the linkage extension part is connected to the back frame body, and a movable seat connected to the front end of the front spring arm is convexly provided at the front end. The movable seat is softly connected to the front support and can move up and down relative to the front support; the seat bracket is rigidly connected to the movable seat.

[0012] In the present utility model, there are two rear supports which are integrally formed and connected to the left and right sides of the front support respectively. There are two elastic bent arms, and each rear support correspondingly supports one elastic bent arm.

[0013] In the present utility model, the rear support includes a rear lower arm and a rear upper arm protruding from the rear side of the rear support. The front end of the rear lower arm is connected to the front support. A rear movable limit groove for accommodating and installing the rear spring arm is provided on the front side of the rear upper arm. A front movable limit groove for accommodating the front spring arm is provided on the rear side of the rear lower arm. The lower end of the rear movable limit groove communicates with the lower end of the front movable limit groove.

[0014] In the present utility model, a plurality of limit convex parts are arranged on the groove bottom surfaces of the front movable limit groove and the rear movable limit groove. A plurality of limit concave grooves are provided on the front spring arm and the rear spring arm, and each limit convex part is snapped into a limit concave groove.

[0015] In the present utility model, the fulcrum member includes a fulcrum body, a fulcrum convex part protruding from the top end of the fulcrum body, and a fulcrum elastic part protruding from the front side of the fulcrum body. The fulcrum body is fitted and installed on the rear side of the rear upper arm. The fulcrum convex part is movably abutted against the bottom end of the back frame body and the rear side of the rear spring arm; a rear soft connection groove is provided on the rear spring arm. The upper end of the fulcrum elastic part extends into the rear soft connection groove. The upper end of the fulcrum elastic part is bent upward and backward and is installed on the bottom end of the back frame body by a rear clamping part to form a soft connection.

[0016] In the present utility model, an inverted hook groove is formed at the connection position of the fulcrum body and the fulcrum convex part. An inverted hook matching part that is fitted in the inverted hook groove is provided on the rear upper arm.

[0017] In the present utility model, a rear clamping avoidance groove is provided on the fulcrum elastic part. A rear clamping groove for the rear clamping part is provided on the front side of the back frame body. The rear clamping part is inserted through the rear clamping avoidance groove and is clamped in the rear clamping groove.

[0018] In the present utility model, a front soft connection groove is provided on the front support. A movable connection part that can move up and down in the front soft connection groove is provided at the bottom of the movable seat. A first front clamping part and a second front clamping part that are fitted with the movable connection part in the front soft connection groove are installed on the front support.

[0019] In the present utility model, the first front clamping member includes a first front clamping main body installed at the bottom of the front support and at least two first front clamping elastic portions protruding upward from the top surface of the first front clamping main body. A first fitting portion is provided on the movable connecting portion, a first front limiting groove is provided on the first front clamping elastic portion, and the first fitting portion is fitted in the first front limiting groove.

[0020] In the present utility model, the second front clamping member includes a main body hook portion and a second front clamping elastic portion protruding from the lower end of the main body hook portion. The main body hook portion hooks on the top of the fitting convex portion of the front support. A second fitting portion is provided on the movable connecting portion, a second front limiting groove is provided on the second front clamping elastic portion, and the second fitting portion is fitted in the second front limiting groove.

[0021] Advantages of the present utility model: The seat-back linkage structure of the present utility model, through the elastic bent arm design of the back support, enables the back support to be adjusted accordingly according to the back curve and movement amplitude of the user. When the user naturally leans backward, the elastic bent arm can deform, ensuring that the back support always fits the back position and posture changes of the user, and effectively dispersing the pressure, avoiding the user from feeling a rigid reaction force, significantly improving the adaptability of the chair, providing a more comfortable sitting posture experience for the user, thereby improving the practicality and health benefits of the chair; in addition, the seat-back linkage structure allows the user not to need to slide the buttocks forward or adjust the back support locking device like a traditional locked back support. This design not only makes it more convenient to adjust the sitting posture, but also helps to maintain the balance of the user, avoiding the risk of slipping out of the seat, thereby improving the safety and stability of the chair. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present utility model will be further described below in conjunction with the drawings and embodiments:

[0023] Figure 1 is a perspective view of the seat-back linkage structure;

[0024] Figure 2 is an exploded view of some parts of the seat-back linkage structure;

[0025] Figure 3 is a perspective view of the back support;

[0026] Figure 4 is a schematic diagram of the cooperation between the support inclined surface and the mating inclined surface;

[0027] Figure 5 is an installation schematic diagram of the fulcrum member;

[0028] Figure 6 is an installation schematic diagram of the first front clamping member and the second front clamping member. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model.

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

[0031] In addition, if there are descriptions involving "first" or "second" in the embodiments of the present utility model, then such descriptions of "first" or "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

[0032] Refer to Figure 1-6 , a seat-back linkage structure applied to a chair, including a main frame 1, a backrest support 2, and a seat support 3. The main frame 1 includes a front support 11 and two rear supports 12 arranged left and right. The two rear supports 12 are integrally formed and connected to the left and right sides of the front support 11 respectively; the backrest support 2 is made of a material with toughness and elasticity. The backrest support 2 includes a backrest body 21, elastic bent arms 22, and a linkage extension part 23 located above the elastic bent arms 22. There are two elastic bent arms 22, and each rear support 12 correspondingly supports one elastic bent arm 22. The elastic bent arm 22 includes a rear elastic arm 221 extending forward and downward from the bottom end of the backrest body 21 and a front elastic arm 222 extending forward and upward from the bottom end of the rear elastic arm 221. The connection position of the rear elastic arm 221 and the front elastic arm 222 can be elastically bent and deformed, so that the upper ends of the rear elastic arm 221 and the front elastic arm 222 can be unfolded and brought closer to each other when the connection position of the rear elastic arm 221 and the front elastic arm 222 deforms.

[0033] Furthermore, a fulcrum member 4 is provided on the rear support 12 and is softly connected to the backrest support 2. The fulcrum member 4 is movably abutted against the bottom end of the backrest body 21 and the rear side of the rear elastic arm 221, so that the backrest body 21 and the rear elastic arm 221 swing back and forth with the fulcrum member 4 as the fulcrum.

[0034] Furthermore, the rear end of the linkage extension portion 23 is connected to the back frame body 21, and a movable seat 24 connected to the front end of the front elastic arm 222 protrudes from the front end. The movable seat 24 is softly connected to the front support 11 and can move up and down relative to the front support 11; the seat bracket 3 is rigidly connected to the movable seat 24 by means of bolt connection.

[0035] In this embodiment, front mounting portions protrude from both the left and right sides of the front support 11. The rear support 12 is in a Y-shaped structure. The rear support 12 includes a rear lower arm 121 and a rear upper arm 122 protruding from the rear side of the rear support 12. The front end of the rear lower arm 121 is connected to the front mounting portion and the front support 11, and a rear mounting portion is provided at the bottom side of the rear end. Branch insertion ends are provided at the bottom ends of the front mounting portion and the rear mounting portion. The branch insertion ends are used to connect the footrest of the rocking chair to suspend the main frame 1.

[0036] In this embodiment, a rear movable limit groove 1221 for accommodating the rear elastic arm 221 is provided on the front side of the rear upper arm 122, and a front movable limit groove 1211 for accommodating the front elastic arm 222 is provided on the rear side of the rear lower arm 121. The lower end of the rear movable limit groove 1221 communicates with the lower end of the front movable limit groove 1211. Among them, the rear movable limit groove 1221 is used to limit the left and right movement of the rear elastic arm 221, and the front movable limit groove 1211 is used to limit the left and right movement of the front elastic arm 222. In this way, the left and right movement of the entire elastic bent arm 22 is restricted, and the left and right constraint positioning of the back bracket 2 and the main frame 1 is realized, ensuring the combined installation quality between the back bracket 2 and the main frame 1.

[0037] In this embodiment, a plurality of limit protrusions 123 are arranged on the groove bottom surfaces of the front movable limit groove 1211 and the rear movable limit groove 1221. A plurality of limit grooves 223 are provided on the front elastic arm 222 and the rear elastic arm 221. Each limit protrusion 123 is engaged into a limit groove 223. By means of the cooperation between the limit protrusions 123 and the limit grooves 223, the soft connection between the movable seat 24 and the front support 11 can be combined to limit the front and rear displacement of the elastic bent arm 22.

[0038] In this embodiment, the fulcrum member 4 is made of a material with toughness and elasticity. The fulcrum member 4 includes a fulcrum body 41, a fulcrum convex portion 42 protruding from the top end of the fulcrum body 41, and a fulcrum elastic portion 43 protruding from the front side of the fulcrum body 41. The fulcrum body 41 is fitted and installed on the rear side of the rear upper arm 122. The fulcrum convex portion 42 is movably abutted against the bottom end of the backrest frame body 21 and the rear side of the rear elastic arm 221. A rear soft connection groove 2211 is provided on the rear elastic arm 221. The upper end of the fulcrum elastic portion 43 extends into the rear soft connection groove 2211 from the rear movable limiting groove 1221. The upper end of the fulcrum elastic portion 43 is bent upward and backward in an arc shape and is installed on the bottom end of the backrest frame body 21 by a rear clamping member 5 to form a soft connection, thereby realizing the soft connection between the backrest support 2 and the fulcrum member 4.

[0039] In this embodiment, a fulcrum fitting groove 1222 is provided on the rear side of the rear upper arm 122. The fulcrum body 41 is fitted in the fulcrum fitting groove 1222. A fulcrum member avoidance groove for the fulcrum elastic portion 43 to extend into the fulcrum fitting groove 1222 is provided in the fulcrum fitting groove 1222, thereby facilitating the installation of the fulcrum elastic portion 43. Further, an inverted hook groove 40 is formed at the connection position between the fulcrum body 41 and the fulcrum convex portion 42. An inverted hook fitting portion 1223 is provided on the rear upper arm 122 and is fitted in the inverted hook groove 40. The inverted hook fitting portion 1223 is supported and inserted into the inverted hook groove 40, which can effectively limit the downward movement of the fulcrum member 4, so that the fulcrum convex portion 42 can, while serving as a fulcrum to support the backrest support 2, play a role in unloading and buffering by relying on the extrusion deformation of the material, and improve the quality when the backrest support 2 and the seat support 3 are linked.

[0040] In this embodiment, a rear clamping avoidance groove 431 is provided on the fulcrum elastic portion 43. A rear clamping groove 211 for the rear clamping member 5 is provided on the front side of the backrest frame body 21. The rear clamping member 5 is inserted through the rear clamping avoidance groove 431 and is clamped in the rear clamping groove 211, thereby realizing the installation of the rear clamping member 5.

[0041] In this embodiment, a front soft connection groove 111 is provided on the front support 11. A movable connection portion 241 capable of moving up and down in the front soft connection groove 111 is provided at the bottom of the movable seat 24. A first front clamping member 6 and a second front clamping member 7 that are installed on the front support 11 and cooperate with the movable connection portion 241 in the front soft connection groove 111 to form a soft connection are provided, thereby making the movable seat 24 and the front support 11 in soft connection.

[0042] In this embodiment, both the first front clamping member 6 and the second front clamping member 7 are made of a material with toughness and elasticity. The first front clamping member 6 includes a first front clamping main body 61 installed at the bottom of the front support 11 and at least two first front clamping elastic parts 62 protruding upward from the top surface of the first front clamping main body 61. A first matching part 242 is provided on the movable connecting part 241. Further, a first front limiting groove 621 is provided on the first front clamping elastic part 62, and the first matching part 242 is fitted in the first front limiting groove 621, so as to realize the fitting connection between the first front clamping elastic part 62 and the first matching part 242.

[0043] In this embodiment, a bottom mounting groove 112 is provided at the bottom of the front support 11, and the first front clamping main body 61 is snap-fitted and mounted in the bottom mounting groove 112; a first front clamping avoidance groove communicating with the front soft connection groove 111 is provided in the bottom mounting groove 112, and the first front clamping elastic part 62 extends into the front soft connection groove 111 from the first front clamping avoidance groove for easy installation.

[0044] In this embodiment, the second front clamping member 7 includes a main body hook part 71 and a second front clamping elastic part 72 protruding from the lower end of the main body hook part 71. The main body hook part 71 hooks on the top 112 of the matching convex part of the front support 11. A second matching part 243 is provided on the movable connecting part 241, so that the movable connecting part 241 is located there; specifically, a second front limiting groove 721 is provided on the second front clamping elastic part 72, and the second matching part 243 is fitted in the second front limiting groove 721, so as to realize the fitting connection between the second front clamping elastic part 72 and the second matching part 243.

[0045] In this embodiment, the seat bracket 3 includes a seat connecting part 31 and a seat frame 32 provided at the front end of the seat connecting part 31. The seat connecting part 31 is installed on the upper end of the movable seat 24 by bolts 8. At least one support inclined surface 244 is provided at the upper end of the movable seat 24, and at least one matching inclined surface 311 corresponding to the support inclined surface 244 is provided on the seat connecting part 31. Both the support inclined surface 244 and the matching inclined surface 311 are inclined forward and downward; when the seat bracket 3 is not pressed, there is a movable gap between the support inclined surface 244 and the matching inclined surface 311; when the seat bracket 3 is pressed, the seat bracket 3 deforms and bends so that the matching inclined surface 311 slides and adheres to the support inclined surface 244, causing the seat bracket 3 to move forward by a certain displacement.

[0046] When the user sits on the chair and applies pressure to the upper part of the backrest bracket 2, through the fulcrum member 4, the backrest bracket 2 uses the linkage extension part 23 to pull the front end of the seat bracket 3 to move upward. When the front end of the backrest bracket 2 moves upward, the fulcrum elastic part 43 of the fulcrum member 4 is pulled and deformed and stretched by the rear clamping member 5, the first front clamping elastic part 62 of the first front clamping member 6 is pulled and deformed and stretched by the first matching part 242, and the second front clamping elastic part 72 of the second front clamping member 7 is pulled and deformed and stretched by the second matching part 243. After the pressure is removed, the fulcrum member 4, the first front clamping member 6 and the second front clamping member 7 all rely on their own material properties to rebound and return to their original positions. Repeating this process enables the backrest bracket 2 and the seat bracket 3 to be interlocked with each other.

[0047] When pressure is applied to the seat bracket 3, since the seat bracket 3 and the backrest bracket 2 are rigidly connected, after the seat bracket 3 deforms and moves downward, it drives the front end of the backrest bracket 2 to move downward. Mutual reverse-direction movement interference occurs between the first front clamping elastic part 62 of the first front clamping member 6 and the first matching part 242 and between the second front clamping elastic part 72 of the second front clamping member 7 and the second matching part 243. After the pressure applied to the seat bracket 3 is removed, the first front clamping member 6 and the second front clamping member 7 use their own material properties to rebound and return to their original positions, thereby enabling the backrest bracket 2 and the seat bracket 3 to be interlocked with each other.

[0048] The above description is only the preferred embodiment of the present invention, and all technical solutions that achieve the purpose of the present invention by basically the same means fall within the protection scope of the present invention.

Claims

1. A seat-back linkage structure applied to a chair, comprising a main frame (1), a backrest support (2) and a seat support (3), characterized in that: The main frame (1) includes a front support (11) and a rear support (12); the back support (2) includes a back frame body (21), an elastic bent arm (22), and a linkage extension part (23) located above the elastic bent arm (22). The elastic bent arm (22) includes a rear elastic arm (221) extending forward and downward from the bottom end of the back frame body (21) and a front elastic arm (222) extending forward and upward from the bottom end of the rear elastic arm (221). The connection position of the rear elastic arm (221) and the front elastic arm (222) is elastically bendable and deformable. A fulcrum member (4) soft-connected to the back support (2) is provided on the rear support (12). The fulcrum member (4) is movably abutted against the bottom end of the back frame body (21) and the rear side of the rear elastic arm (221). The rear end of the linkage extension part (23) is connected to the back frame body (21), and a movable seat (24) connected to the front end of the front elastic arm (222) is convexly provided at the front end. The movable seat (24) is soft-connected to the front support (11) and can move up and down relative to the front support (11). The seat support (3) is rigidly connected to the movable seat (24).

2. The seat-back linkage structure applied to a chair according to claim 1, characterized in that: There are two rear supports (12), which are integrally formed and connected to the left and right sides of the front support (11) respectively. There are two elastic bent arms (22), and each rear support (12) correspondingly supports one elastic bent arm (22).

3. A seat-back linkage structure applied to a chair according to claim 1 or 2, characterized in that: The rear support (12) includes a rear lower arm (121) and a rear upper arm (122) protruding from the rear side of the rear support (12). The front end of the rear lower arm (121) is connected to the front support (11). A rear movable limit groove (1221) for accommodating and installing the rear elastic arm (221) is provided on the front side of the rear upper arm (122). A front movable limit groove (1211) for accommodating the front elastic arm (222) is provided on the rear side of the rear lower arm (121). The lower end of the rear movable limit groove (1221) communicates with the lower end of the front movable limit groove (1211).

4. The seat-back linkage structure applied to a chair according to claim 3, characterized in that: A plurality of limit convex parts (123) are arranged on the bottom surfaces of the front movable limit groove (1211) and the rear movable limit groove (1221). A plurality of limit grooves (223) are provided on the front elastic arm (222) and the rear elastic arm (221). Each limit convex part (123) is snapped into a limit groove (223).

5. A seat-back linkage structure applied to a chair according to claim 1 or 2, characterized in that: The fulcrum member (4) includes a fulcrum body (41), a fulcrum convex part (42) protruding from the top end of the fulcrum body (41), and a fulcrum elastic part (43) protruding from the front side of the fulcrum body (41). The fulcrum body (41) is fitted and installed on the rear side of the rear upper arm (122). The fulcrum convex part (42) is movably abutted against the bottom end of the back frame body (21) and the rear side of the rear elastic arm (221). A rear soft connection groove (2211) is provided on the rear elastic arm (221). The upper end of the fulcrum elastic part (43) extends into the rear soft connection groove (2211). The upper end of the fulcrum elastic part (43) is bent upward and backward in an arc and is installed on the bottom end of the back frame body (21) by a rear clamping member (5) to form a soft connection.

6. The seat-back linkage structure applied to a chair according to claim 5, characterized in that: A barb groove (40) is formed at the connection position of the fulcrum body (41) and the fulcrum convex part (42), and a barb engaging part (1223) that fits in the barb groove (40) is provided on the rear upper arm (122).

7. The seat-back linkage structure applied to a chair according to claim 5, wherein: A rear card avoiding groove (431) is provided on the fulcrum elastic part (43), and a rear card slot (211) for the rear engaging member (5) is provided on the front side of the back frame body (21). The rear engaging member (5) is inserted through the rear card avoiding groove (431) and is clamped in the rear card slot (211).

8. A seat-back linkage structure applied to a chair according to claim 1 or 2, characterized in that: A front soft connection groove (111) is provided on the front support (11), and a movable connection part (241) that can move up and down in the front soft connection groove (111) is provided at the bottom of the movable seat (24). A first front engaging member (6) and a second front engaging member (7) that form a soft connection with the movable connection part (241) in the front soft connection groove (111) are installed on the front support (11).

9. The seat-back linkage structure applied to a chair according to claim 8, wherein: The first front engaging member (6) includes a first front engaging main body (61) installed at the bottom of the front support (11) and at least two first front engaging elastic parts (62) protruding upward from the top surface of the first front engaging main body (61). A first engaging part (242) is provided on the movable connection part (241), a first front limiting groove (621) is provided on the first front engaging elastic part (62), and the first engaging part (242) is fitted in the first front limiting groove (621).

10. A seat-back linkage structure applied to a chair according to claim 8, characterized in that: The second front engaging member (7) includes a main body hook part (71) and a second front engaging elastic part (72) protruding from the lower end of the main body hook part (71). The main body hook part (71) is hooked on the top of the engaging convex part (112) of the front support (11). A second engaging part (243) is provided on the movable connection part (241), a second front limiting groove (721) is provided on the second front engaging elastic part (72), and the second engaging part (243) is fitted in the second front limiting groove (721).

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