Zero-gravity backrest linkage structure and seat

Abstract

The application relates to a zero-gravity backrest linkage structure and a seat, and relates to the technical field of seats. The zero-gravity backrest linkage structure comprises a chair plate support, a chair back support movably connected to the chair plate support, and a chair back driving element for driving the chair back support to move relative to the chair plate support; the chair back support comprises a sliding side plate, a first guide block and a second guide block installed on the sliding side plate; the chair plate support comprises a supporting side plate; the supporting side plate is provided with a first guide groove for sliding arrangement of the first guide block and a second guide groove for sliding arrangement of the second guide block; the first guide groove is inclined from front to back towards the direction of the seat surface of the chair plate support; and the second guide groove is inclined from front to back towards the direction of the seat surface of the chair plate support. The application has the effect of improving the comfort of the zero-gravity seat.

Description

Technical Field

[0001] This application relates to the field of seating technology, and in particular to a zero-gravity backrest linkage structure and a seat. Background Technology

[0002] As living standards improve, people have higher demands for the comfort of their everyday seating. Traditional chairs, such as office chairs and lounge chairs, typically only offer simple backrest angle or seat height adjustments, which are insufficient to meet users' needs for deep relaxation and scientific support. To meet users' needs for comfortable posture, a "zero-gravity" posture chair has gradually been developed.

[0003] This zero-gravity seat primarily simulates the posture astronauts adopt during spacecraft launch. Its aim is to distribute body weight evenly across the back, hips, and legs through a scientifically designed angle distribution, thereby reducing pressure on the spine and joints and improving user comfort. Existing zero-gravity seats typically tilt the backrest backward while the leg rests are raised when the user leans back, providing support for the back, hips, and legs to create a so-called "zero-gravity" angle.

[0004] Regarding the aforementioned technologies, as the user's sitting posture changes, the backrest will slide against the user's back when it tilts backward, resulting in a rubbing sensation and reducing the user's experience. The inventor believes that a zero-gravity chair with better comfort can be provided. Utility Model Content

[0005] To improve the comfort of zero-gravity seats, this application provides a zero-gravity backrest linkage structure and a seat.

[0006] Firstly, this application provides a zero-gravity backrest linkage structure, which adopts the following technical solution: A zero-gravity backrest linkage structure includes a chair base support, a backrest support movably connected to the chair base support, and a backrest drive member for driving the backrest support to move relative to the chair base support. The backrest support includes a sliding side plate and a first guide block and a second guide block mounted on the sliding side plate. The chair base support includes a support side plate. The support side plate has a first guide groove for the first guide block to slide and a second guide groove for the second guide block to slide. The first guide groove is inclined from front to back towards the seat surface of the chair base support. The second guide groove is inclined from front to back towards the seat surface of the chair base support.

[0007] By adopting the above technical solution, the chair back support, which is movably connected to the chair back support, and the chair back drive component can drive the chair back support to move relative to the chair back support, thereby achieving the tilting movement of the chair back support. The first guide groove is inclined from front to back towards the seat surface of the chair back support, and the second guide groove is inclined from front to back towards the seat surface of the chair back support. Moreover, the first guide block is slidably arranged in the first guide groove and the second guide block is slidably arranged in the second guide groove, which enables the chair back support to move along a predetermined direction, improves the movement stability of the chair back support relative to the chair back support, and also helps the chair back support and chair back support to form a zero-gravity support state.

[0008] Optionally, one end of the backrest drive member is movably connected to the seat support bracket, and the other end is movably connected to the backrest support bracket; the backrest drive member drives the backrest support bracket closer to the seat support bracket, the first guide block slides to the front end of the first guide groove, and the second guide block slides to the front end of the second guide groove; the backrest drive member drives the backrest support bracket away from the seat support bracket, the first guide block slides to the rear end of the first guide groove, and the second guide block slides to the rear end of the second guide groove.

[0009] By adopting the above technical solution, one end of the chair back drive component is movably connected to the chair base support, and the other end is movably connected to the chair back support, enabling the chair back support to move relative to the chair base support. When the first guide block and the second guide block slide to the front end of the first guide groove and the second guide groove respectively, the chair back support moves along the predetermined zero-gravity support direction. When the first guide block and the second guide block slide to the rear end of the first guide groove and the second guide groove respectively, the chair back support can move along the normal support direction. This improves the sliding stability of the chair back support and enhances the comfort of the support.

[0010] Optionally, the first guide block includes a first guide shaft with one end fixed to the chair back support and the other end passing through the first guide groove, and a first bushing axially sleeved on the first guide shaft; the first bushing includes a first sliding part that slides with the inner wall of the first guide groove and a first support part that abuts against the chair back support and the support side plate.

[0011] By adopting the above technical solution, the first guide block is provided with a first guide shaft and an axially sleeved first bushing. The first sliding part of the first bushing slides with the inner wall of the first guide groove, which can reduce the friction between the first guide block and the first guide groove, making the sliding of the first guide block in the first guide groove smoother. The first support part abuts against the backrest bracket and the support side plate, which can reduce the contact between the chair board bracket and the backrest bracket and improve the smoothness of sliding.

[0012] Optionally, the inner groove edge of the first guide groove is provided with a first protruding ring; the first guide block further includes a first limiting ring sleeved on the first guide shaft and abutting against the end of the first sliding part; the end of the first guide shaft is also provided with a first anti-disengagement ring abutting against the first limiting ring.

[0013] By adopting the above technical solution, the inner groove edge of the first guide groove is provided with a first convex ring, the first guide block is provided with a first limiting ring that abuts against the end of the first sliding part, and the end of the first guide shaft is provided with a first anti-detachment ring that abuts against the first limiting ring, which can reduce the probability of the first guide block detaching in the first guide groove and improve the stability of the chair back support on the chair board support.

[0014] Optionally, the second guide block includes a second guide shaft with one end fixed to the chair back support and the other end passing through the second guide groove, and a second bushing axially sleeved on the second guide shaft; the second bushing includes a second sliding part that slides with the inner wall of the second guide groove and a second support part that abuts against the chair back support and the support side plate.

[0015] By adopting the above technical solution, one end of the second guide shaft is fixed to the chair back support and passes through the second guide groove. It is axially sleeved with the second bushing. The second sliding part of the second bushing cooperates with the inner wall of the second guide groove, which enables the second guide block to slide smoothly in the second guide groove. The second support part abuts between the chair back support and the support side plate, which can reduce the contact between the chair board support and the chair back support, improve the smoothness of sliding, and also improve the stability of the zero-gravity backrest linkage structure.

[0016] Optionally, the inner groove edge of the second guide groove is provided with a second protruding ring; the second guide block further includes a second limiting ring sleeved on the second guide shaft and abutting against the end of the second sliding part; the end of the second guide shaft is also provided with a second anti-disengagement ring abutting against the second limiting ring.

[0017] By adopting the above technical solution, the inner side of the second guide groove is provided with a second convex ring, the second guide block includes a second limiting ring sleeved on the second guide shaft, and the end of the second guide shaft is provided with a second anti-detachment ring abutting against the second limiting ring, which can reduce the probability of the second guide block detaching from the second guide groove and improve the stability and reliability of the zero gravity backrest linkage structure.

[0018] Secondly, this application provides a zero-gravity seat, which adopts the following technical solution: A zero-gravity seat includes the aforementioned zero-gravity backrest linkage structure, a base support, a seat board linkage structure movably mounted on the seat board support and the base support, a footrest linkage structure movably mounted on the front end of the seat board support, and a footrest drive component for driving the seat board linkage structure and the footrest linkage structure to move.

[0019] By adopting the above technical solution, the zero-gravity seat features a zero-gravity backrest linkage structure, allowing the backrest support to move relative to the seat frame support. The first guide block slides within the first guide groove, and the second guide block slides within the second guide groove, facilitating the adjustment of the backrest support's direction of movement. It also includes a seat frame linkage structure and a leg support linkage structure, driven by a leg support driver, enabling coordinated adjustment of hip and leg support, providing users with a more comfortable zero-gravity seating experience.

[0020] Optionally, the tripod linkage structure includes a tripod drive bracket, a first tripod link connected to both ends of the tripod drive bracket, a second tripod link hinged to the support side plate and the base bracket, a third tripod link hinged to the second tripod link and the first tripod link, a fourth tripod link hinged to the end of the first tripod link, and a foot support hinged to the third tripod link and the fourth tripod link; the tripod drive member is used to telescopically drive the tripod drive bracket to swing relative to the chair support.

[0021] By adopting the above technical solution, the links of the footrest linkage structure are hinged to each other, and the footrest drive component extends and retracts to drive the footrest drive bracket to swing relative to the rear bracket, thereby realizing the movement and adjustment of the footrest linkage structure. In turn, it works in conjunction with the zero-gravity backrest linkage structure to enable the seat to achieve zero-gravity adjustment.

[0022] Optionally, the chair board linkage structure includes a drive link hinged to the base bracket and the support side plate; the leg drive drives the chair board bracket to rotate around the hinge point between the drive link and the base bracket.

[0023] By adopting the above technical solution, the drive linkage of the chair panel linkage structure is hinged to the mounting rod and the support side plate. The foot drive component can drive the chair panel support to rotate around the hinge point between the drive linkage and the mounting rod, thereby realizing the movement of the chair panel support. Combined with the zero-gravity backrest linkage structure and the foot linkage structure, the function of the zero-gravity seat is improved, and the comfort of the zero-gravity seat is enhanced.

[0024] Optionally, the leg drive component is an electric push rod; one end of the electric push rod is hinged to the leg drive bracket, and the other end is hinged to the chair board bracket.

[0025] By adopting the above technical solution, using an electric push rod as the leg drive component, with one end hinged to the leg drive bracket and the other end hinged to the seat support bracket, the extension and retraction drive of the leg drive bracket relative to the seat support bracket can be realized, thereby driving the movement of the leg linkage structure and the seat linkage structure. This is beneficial for adjusting the tilt angle of the seat support bracket and for cooperating with the backrest bracket and the leg drive bracket, thus improving the zero-gravity support effect and user comfort of the seat.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. A zero-gravity backrest linkage structure, by setting a chair board support, a backrest support, and a backrest drive component, enables the backrest support to move relative to the chair board support, thereby adjusting the zero-gravity support position of the backrest support and improving the tilting effect of the backrest support; by setting a first guide block of the backrest support to slide in a first guide groove of the chair board support and a second guide block of the backrest support to slide in a second guide groove of the chair board support, the sliding stability of the backrest support can be improved, reducing the back-rubbing sensation during use and improving the user experience; 2. By setting a first guide shaft and a first bushing sleeved outside the first guide shaft, the friction between the first guide block and the first guide groove is reduced. Similarly, the friction between the second guide block and the second guide groove is reduced by setting a second guide shaft and a second bushing sleeved outside the second guide shaft, making the sliding of the first guide block in the first guide groove and the sliding of the second guide block in the second guide groove smoother. The first guide groove has a first convex ring on its inner groove edge, and the first guide block also has a first limiting ring and a first anti-detachment ring, which reduces the probability of the first guide block detaching in the first guide groove. The second guide groove has a second convex ring on its inner groove edge, and the second guide block also has a second limiting ring and a second anti-detachment ring, which reduces the probability of the second guide block detaching in the second guide groove, thus improving the smoothness of sliding between the chair back support and the chair board support. 3. A zero-gravity seat, by setting a base support, a footrest linkage structure and a footrest drive component, can cooperate with a zero-gravity backrest linkage structure to provide support for the user's feet and improve the comfort of the seat in the zero-gravity support state. 4. By setting the drive linkage of the chair board linkage structure, the power of the leg drive component can be converted into the movement of the chair board linkage structure, so that the chair board support and the backrest support can tilt, thereby improving the zero-gravity support effect and the comfort of the seat. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the zero-gravity backrest linkage structure in the embodiments of this application.

[0028] Figure 2 This is a schematic diagram of the chair support structure in an embodiment of this application.

[0029] Figure 3 This is an exploded view of the zero-gravity backrest linkage structure in the embodiments of this application.

[0030] Figure 4 This is a schematic diagram of the structure of the first guide block in the embodiment of this application.

[0031] Figure 5 This is an exploded view of the second guide block in an embodiment of this application.

[0032] Figure 6This is a structural schematic diagram of the zero-gravity seat in the embodiments of this application.

[0033] Figure 7 This is a schematic diagram of the chair board linkage structure in the embodiments of this application.

[0034] Explanation of reference numerals in the attached drawings: 1. Chair seat bracket; 11. Chair seat mounting bracket; 12. Support side plate; 121. First guide groove; 1211. First protruding ring; 122. Second guide groove; 1221. Second protruding ring; 13. Front support frame; 14. Rear support frame; 2. Chair back bracket; 21. Sliding side plate; 22. Chair back drive frame; 23. First guide block; 231. First guide shaft; 2311. First anti-detachment ring; 232. First bushing; 2321. First sliding part; 2322. First support part; 233. First limiting ring; 24. Second... 241. Guide block; 241. Second guide shaft; 2411. Second anti-detachment ring; 242. Second bushing; 2421. Second sliding part; 2422. Second support part; 243. Second limiting ring; 3. Backrest drive component; 4. Base bracket; 41. Seat base; 42. Base crossbar; 43. Mounting rod; 5. Leg linkage structure; 51. Leg drive bracket; 52. First leg connecting rod; 53. Second leg connecting rod; 54. Third leg connecting rod; 55. Fourth leg connecting rod; 56. Foot support bracket; 6. Leg drive component; 7. Drive connecting rod. Detailed Implementation

[0035] The following is in conjunction with the appendix Figure 1-7 This application will be described in further detail.

[0036] This application discloses a zero-gravity backrest linkage structure. (Refer to...) Figure 1 A zero-gravity backrest linkage structure includes a chair board support 1, a backrest support 2 movably connected to the chair board support 1, and a backrest drive member 3 that drives the backrest support 2 to move relative to the chair board support 1.

[0037] Reference Figure 1 and Figure 2 The chair seat support 1 includes a seat mounting frame 11, two supporting side plates 12 mounted on the bottom of the seat mounting frame 11, a front support frame 13 mounted at both ends on the front ends of the supporting side plates 12, and a rear support frame 14 mounted at both ends on the rear ends of the supporting side plates 12. The chair back support 2 includes sliding side plates 21 distributed on both sides and a chair back drive frame 22 arranged between the sliding side plates 21. One end of the chair back drive component 3 is movably connected to the front support frame 13, and the other end is movably connected to the chair back drive frame 22. Activating the chair back drive component 3 can drive the chair back drive frame 22 to move back and forth relative to the front support frame 13, thereby realizing the backrest support 2 moving back and forth relative to the chair seat support 1. In this embodiment, the chair back drive component 3 is an electric push rod, with the motor end hinged to the front support frame 13 and the push rod end hinged to the chair back drive frame 22.

[0038] Reference Figure 2 The backrest support 2 also includes a first guide block 23 mounted on the two sliding side plates 21 and a second guide block 24 located behind the first guide block 23. The support side plate 12 near the rear support frame 14 has a first guide groove 121 for the first guide block 23 to slide along and a second guide groove 122 for the second guide block 24 to slide along. The first guide groove 121 is inclined from front to back towards the seat surface of the seat mounting frame 11, and the second guide groove 122 is inclined from front to back towards the seat surface of the seat mounting frame 11.

[0039] Reference Figure 3 and Figure 4 The first guide block 23 includes a first guide shaft 231, one end of which is fixed to the chair back bracket 2 and the other end of which passes through the first guide groove 121; a first bushing 232 axially sleeved on the first guide shaft 231; and a first limiting ring 233 sleeved on the first guide shaft 231 and abutting against the inner end of the first bushing 232. The end of the first guide shaft 231 is provided with a first anti-detachment ring 2311 that abuts against the first limiting ring 233. The outer diameter of the first anti-detachment ring 2311 is larger than the diameter of the opening at the axis of the first limiting ring 233 through which the first guide shaft 231 passes.

[0040] Reference Figure 2 and Figure 4 The first bushing 232 also includes a first sliding part 2321 that slides in cooperation with the inner wall of the first guide groove 121 and a first support part 2322 that abuts against the backrest bracket 2 and the support side plate 12.

[0041] Reference Figure 3 and Figure 4 The inner edge of the first guide groove 121 is provided with an integrally formed first protruding ring 1211. The inner ring of the first protruding ring 1211 abuts against the first bushing 232, separating the contact between the first limiting ring 233 and the first guide groove 121. The first support part 2322 cooperates with the first limiting ring 233 to confine the first guide shaft 231 within the first guide groove 121, reducing the probability of the first guide shaft 231 dislodging. The inner ring of the first sliding part 2321 fits against the first guide shaft 231, and the outer ring slides and cooperates with the first guide groove 121, reducing the sliding friction of the first guide block 23 within the first guide groove 121 and improving the sliding stability of the first guide block 23 within the first guide groove 121.

[0042] Reference Figure 2 and Figure 3The second guide block 24 includes a second guide shaft 241 with one end fixed to the chair back bracket 2 and the other end passing through the second guide groove 122, a second bushing 242 axially sleeved on the second guide shaft 241, and a second limiting ring 243 sleeved on the second guide shaft 241 and abutting against the inner end of the second bushing 242.

[0043] Reference Figure 3 and Figure 5 The end of the second guide shaft 241 is also provided with a second anti-detachment ring 2411, which abuts against the second limiting ring 243, and its outer diameter is larger than the diameter of the opening in the center of the second limiting ring 243 through which the guide shaft passes, thereby playing an axial limiting role. The second bushing 242 includes a second sliding part 2421 that slides with the inner wall of the second guide groove 122 and a second support part 2422 that abuts against the backrest bracket 2 and the support side plate 12.

[0044] Reference Figure 3 and Figure 5 The inner side of the second guide groove 122 is provided with an integrally formed second convex ring 1221. The inner ring of the second convex ring 1221 abuts against the second bushing 242, separating the contact between the second limiting ring 243 and the second guide groove 122. Through the cooperation between the second support part 2422 and the second limiting ring 243, the second guide shaft 241 is confined within the second guide groove 122, reducing the probability of the second guide shaft 241 dislodging. The inner ring of the second sliding part 2421 fits against the second guide shaft 241, and the outer ring slides with the second guide groove 122, reducing the sliding friction of the second guide block 24 within the second guide groove 122 and improving the sliding stability of the second guide block 24 within the second guide groove 122.

[0045] Reference Figure 2 and Figure 3 When the backrest drive component 3 retracts, it drives the backrest support 2 closer to the seat support 1. At this time, the first guide block 23 slides towards the front end of the first guide groove 121, and the second guide block 24 slides towards the front end of the second guide groove 122, restricting the tilting direction of the backrest support 2. When the backrest drive component 3 extends, it drives the backrest support 2 away from the seat support 1. At this time, the first guide block 23 slides towards the rear end of the first guide groove 121, and the second guide block 24 slides towards the rear end of the second guide groove 122, restricting the tilting angle and movement direction of the backrest support 2.

[0046] Reference Figures 1 to 5The implementation principle of the zero-gravity backrest linkage structure in this application embodiment is as follows: When the telescopic rod of the backrest drive member 3 retracts, it pulls the backrest support 2 closer to the seat support 1. The first guide blocks 23 on both sides of the seat support 1 slide towards the front end in the first guide groove 121, and the second guide blocks 24 slide towards the front end in the second guide groove 122. Due to the directional movement of the first guide blocks 23 and the second guide blocks 24, the backrest support 2 moves along a predetermined inclined trajectory, realizing zero-gravity linkage between the backrest support 2 and the seat support 1. When the telescopic rod of the backrest drive member 3 extends, it pushes the backrest support 2 away from the seat support 1. The first guide blocks 23 on both sides of the seat support 1 slide towards the rear end in the first guide groove 121, and the second guide blocks 24 slide towards the rear end in the second guide groove 122. Due to the directional movement of the first guide blocks 23 and the second guide blocks 24, the backrest support 2 resets along a predetermined trajectory.

[0047] This application also discloses a zero-gravity seat. (Refer to...) Figure 6 A zero-gravity seat includes a base support 4, a zero-gravity backrest linkage structure, a seat board linkage structure movably mounted on the seat board support 1 and the base support 4, a footrest linkage structure 5 movably mounted on the front end of the seat board support 1, and a footrest drive member 6 for driving the seat board linkage structure and the footrest linkage structure 5 to move.

[0048] Reference Figure 6 The base support 4 includes a seat base 41, a base crossbar 42 mounted on the upper end of the seat base 41, and mounting rods 43 respectively mounted on both ends of the base crossbar 42. The leg linkage structure 5 includes a leg drive support 51, a first leg connecting rod 52 connected to both ends of the leg drive support 51, a second leg connecting rod 53 hinged to the support side plate 12 and the mounting rod 43, a third leg connecting rod 54 hinged to the second leg connecting rod 53 and the first leg connecting rod 52, a fourth leg connecting rod 55 hinged to the end of the first leg connecting rod 52, and a foot support 56 hinged to the third leg connecting rod 54 and the fourth leg connecting rod 55.

[0049] Reference Figure 6The first leg link 52 is hinged to the front end of the support side plate 12, and the two ends of the leg drive bracket 51 are respectively fixed to the first leg link 52 on both sides. The leg drive component 6 is an electric push rod, one end of which is hinged to the leg drive bracket 51, and the other end is hinged to the rear support frame 14. The push-pull rod of the leg drive component 6 drives the leg drive bracket 51 to move closer to or further away from the rear support frame 14. The leg drive bracket 51 drives the first leg link 52 to rotate around the hinge point with the support side plate 12, and the first leg link 52 drives the second leg link 53 to rotate around the hinge point with the mounting rod 43. The third leg link 54 and the fourth leg link 55 unfold forward of the seat under the push of the first leg link 52 and the second leg link 53, and the footrest bracket 56 supports the user's legs to lift up.

[0050] Reference Figure 1 and Figure 7 The chair seat linkage structure includes a drive link 7 hinged to the mounting rod 43 and the supporting side plate 12. The push-pull rod of the leg drive component 6 drives the leg linkage structure 5 to move. The second leg link 53 in the leg linkage structure 5 rotates around the hinge point with the mounting rod 43, transmitting torque to the supporting side plate 12. The movement of the supporting side plate 12 is transmitted to the drive link 7. The drive link 7 rotates around the hinge point with the mounting rod 43, causing the chair seat support 1 to tilt backward as a whole. This tilting of the chair seat support 1, in conjunction with the foot seat support 56 and the backrest support 2, provides effective support for the user's buttocks, improving the comfort of the zero-gravity seat.

[0051] Reference Figures 1 to 7 The implementation principle of a zero-gravity seat in this application embodiment is as follows: When the backrest drive member 3 retracts, it drives the backrest support 2 to approach the seat support 1. The first guide block 23 on the backrest support 2 moves forward in the first guide groove 121 on the seat support 1, and the second guide block 24 on the backrest support 2 moves forward in the second guide groove 122 on the seat support 1, forming the backrest support 2 tilted relative to the seat support 1; the footrest drive member 6 extends, and the transmission footrest linkage structure 5 unfolds towards the front of the seat. The footrest support 56 supports the user's legs and feet to lift up, and the transmission to the seat support linkage structure causes the seat support 1 to tilt backward, which together with the backrest linkage structure forms the support mode of the zero-gravity seat.

[0052] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A zero-gravity backrest linkage structure, characterized in that, The device includes a chair base support (1), a backrest support (2) movably connected to the chair base support (1), and a backrest drive member (3) that drives the backrest support (2) to move relative to the chair base support (1). The backrest support (2) includes a sliding side plate (21) and a first guide block (23) and a second guide block (24) mounted on the sliding side plate (21). The chair base support (1) includes a support side plate (12). The support side plate (12) has a first guide groove (121) for the first guide block (23) to slide and a second guide groove (122) for the second guide block (24) to slide. The first guide groove (121) is inclined from front to back towards the seat surface of the chair base support (1). The second guide groove (122) is inclined from front to back towards the seat surface of the chair base support (1).

2. The zero-gravity backrest linkage structure according to claim 1, characterized in that, One end of the chair back drive member (3) is movably connected to the chair board support (1), and the other end is movably connected to the chair back support (2); the chair back drive member (3) drives the chair back support (2) to approach the chair board support (1), the first guide block (23) slides to the front end of the first guide groove (121), and the second guide block (24) slides to the front end of the second guide groove (122); the chair back drive member (3) drives the chair back support (2) away from the chair board support (1), the first guide block (23) slides to the rear end of the first guide groove (121), and the second guide block (24) slides to the rear end of the second guide groove (122).

3. The zero-gravity backrest linkage structure according to claim 1, characterized in that, The first guide block (23) includes a first guide shaft (231) with one end fixed to the chair back support (2) and the other end passing through the first guide groove (121) and a first bushing (232) axially sleeved on the first guide shaft (231); the first bushing (232) includes a first sliding part (2321) that slides in cooperation with the inner wall of the first guide groove (121) and a first support part (2322) that abuts against the chair back support (2) and the support side plate (12).

4. The zero-gravity backrest linkage structure according to claim 3, characterized in that, The inner groove edge of the first guide groove (121) is provided with a first protruding ring (1211); the first guide block (23) further includes a first limiting ring (233) sleeved on the first guide shaft (231) and abutting against the end of the first sliding part (2321); the end of the first guide shaft (231) is also provided with a first anti-detachment ring (2311) abutting against the first limiting ring (233).

5. The zero-gravity backrest linkage structure according to claim 3, characterized in that, The second guide block (24) includes a second guide shaft (241) with one end fixed to the chair back support (2) and the other end passing through the second guide groove (122) and a second bushing (242) axially sleeved on the second guide shaft (241); the second bushing (242) includes a second sliding part (2421) that slides with the inner wall of the second guide groove (122) and a second support part (2422) that abuts against the chair back support (2) and the support side plate (12).

6. The zero-gravity backrest linkage structure according to claim 5, characterized in that, The inner groove edge of the second guide groove (122) is provided with a second protruding ring (1221); the second guide block (24) also includes a second limiting ring (243) sleeved on the second guide shaft (241) and abutting against the end of the second sliding part (2421); the end of the second guide shaft (241) is also provided with a second anti-detachment ring (2411) abutting against the second limiting ring (243).

7. A zero-gravity seat, characterized in that, It includes the zero-gravity backrest linkage structure as described in any one of claims 1 to 6, the base bracket (4), the chair board linkage structure movably mounted on the chair board bracket (1) and the base bracket (4), the leg linkage structure (5) movably mounted on the front end of the chair board bracket (1), and the leg drive member (6) for driving the chair board linkage structure and the leg linkage structure (5) to move.

8. A zero-gravity seat according to claim 7, characterized in that, The tripod linkage structure (5) includes a tripod drive bracket (51), a first tripod link (52) connected to both ends of the tripod drive bracket (51), a second tripod link (53) hinged to the support side plate (12) and the base bracket (4), a third tripod link (54) hinged to the second tripod link (53) and the first tripod link (52), a fourth tripod link (55) hinged to the end of the first tripod link (52), and a foot support bracket (56) hinged to the third tripod link (54) and the fourth tripod link (55); the tripod drive member (6) is used to extend and retract to drive the tripod drive bracket (51) to swing relative to the chair support (1).

9. A zero-gravity seat according to claim 8, characterized in that, The chair board linkage structure includes a drive link (7) hinged to the base bracket (4) and the support side plate (12); the leg drive (6) drives the chair board bracket (1) to rotate around the hinge point between the drive link (7) and the base bracket (4).

10. A zero-gravity seat according to claim 8, characterized in that, The leg drive (6) is an electric push rod; one end of the electric push rod is hinged to the leg drive bracket (51), and the other end is hinged to the chair board bracket (1).

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