Seat with backrest adjusting function

Abstract

The utility model relates to the technical field of seats, in particular to a seat with a backrest adjusting function, which comprises a seat plate, a backrest plate mounted on the inner side of the back of the seat plate, a locking component mounted between the backrest plate and the seat plate, a telescopic component mounted in the middle of the locking component, one side of the telescopic component connected with the backrest plate, and the other side of the telescopic component connected with the backrest plate. The other side of the telescopic part is connected with the locking part, the telescopic part drives the back-and-forth position adjustment of the backrest plate through telescopic adjustment, and the locking part is used for locking and fixing the telescopic part after the telescopic part is reset. According to the seat with the backrest adjusting function, the telescopic component is arranged, so that the backrest plate can be driven to move back and forth through telescopic adjustment, and the position of the backrest can be flexibly adjusted. When a user needs to work in a straight sitting posture or relax, lean and rest, the user can adjust the position of the backrest according to the requirements of the user, the diversified requirements for supporting the backrest of the seat in different use scenes are met, and compared with a traditional seat with a fixed backrest, the applicability of the seat is greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of seating technology, and more specifically, to a seat with backrest adjustment function. Background Technology

[0002] In the field of seating technology, as people's demands for quality of life continue to rise, the functionality and comfort of seats are receiving increasing attention. Traditionally, the backrest and seat are often fixedly connected, a design with several drawbacks. For example, when a user leans back, the seat back, especially the lumbar support, can easily detach from the lower back, creating a gap. This causes the seat to lose effective support for the lower back, a phenomenon known as "lumbar slippage," which means the spine cannot receive adequate support. Prolonged sitting can easily lead to various health problems.

[0003] To address the aforementioned problems, those skilled in the art have made a series of improvements to existing chairs. For example, patent application number 202020567360.0 discloses an office chair with an adjustable backrest. This office chair includes a seat and an extension plate. The extension plate is embedded in the front of the seat, and a through groove is opened on the rear side. A slide rail is fixed to the inner wall with screws, and a rack is slidably embedded in the slide rail. A rotating shaft is rotatably connected between two opposite side walls of the seat via bearings. Secondary gears are fixedly connected to both ends of the rotating shaft, and a transmission gear is fixedly sleeved on the middle outer wall. Primary gears are rotatably embedded on both sides of the seat via bearings, and a swing frame is fixedly connected between the rotating shafts of the two primary gears. In use, tilting the backrest causes the primary gears to mesh with the secondary gears, accelerating the transmission. The transmission gear then pushes the rack forward, thereby pushing the extension plate outward. The backrest tilt angle is fixed by locking the transmission gears. The extension plate supports the buttocks and lower thighs, helping to maintain a good sitting posture. However, this solution still has shortcomings. The backrest does not provide good support for the user's lower back and does not conform well to the human back. Users are still prone to lower back pain after prolonged use. Utility Model Content

[0004] The purpose of this invention is to provide a seat with a backrest adjustment function to solve the problem mentioned in the background art that the backrest cannot provide good support for the user's waist and cannot fit the human back well, so that the user is still prone to back pain after long-term use.

[0005] To achieve the above objectives, this utility model provides a seat with backrest adjustment function, including a seat panel, a backrest panel installed on the inner side of the back of the seat panel, a locking component installed between the backrest panel and the seat panel, a telescopic component installed in the middle of the locking component, one side of the telescopic component connected to the backrest panel, and the other side of the telescopic component connected to the locking component. The telescopic component adjusts the front and back position of the backrest panel by telescopic adjustment, and the locking component is used to lock and fix the telescopic component after it is reset.

[0006] This configuration includes a backrest panel (2) installed on the inner side of the seat panel (1), with a locking component (3) between them. A telescopic component (5) is installed in the middle of the locking component (3), and the telescopic component (5) is connected to both the backrest panel (2) and the locking component (3). By adjusting the telescopic component (5), its length is changed, thereby moving the backrest panel (2) back and forth. When the backrest panel (2) is adjusted to a suitable position, the locking component (3) is used to reset and lock the telescopic component (5) to prevent the backrest panel (2) from changing position.

[0007] Preferably, a decorative cover is installed on the outer side of the back of the locking component (3).

[0008] This feature involves installing a decorative cover plate (4) on the outer side of the back of the locking component (3) to cover the back of the locking component (3).

[0009] Preferably, the locking component (3) includes a housing, a locking knob is rotatably connected to one side of the housing, a torsion spring is installed at the shaft of the locking knob, a pin plate is installed at the upper end of the torsion spring, a drive rod is installed at the lower end of the locking knob near the torsion spring, and a pin hole is opened on one side of the outer wall of the telescopic component (5). When the locking knob is rotated manually, it drives the lower end of the torsion spring to move, and drives the upper end of the torsion spring to move through the lever action, so as to lock and unlock the pin plate and the pin hole.

[0010] This locking component (3) consists of a housing (31), a locking knob (32), a torsion spring (33), a pin plate (34), and a drive rod (35). When the locking knob (32) is manually rotated, the lower end of the torsion spring (33) moves. Since the upper end of the torsion spring (33) is equipped with a pin plate (34), the upper end of the torsion spring (33) will move the pin plate (34) by lever. When the pin plate (34) is inserted into the pin hole (511) on the outer wall of the telescopic component (5), the telescopic component (5) is locked. Rotating the locking knob (32) in the opposite direction will pull the pin plate (34) out of the pin hole (511) and unlock the component.

[0011] Preferably, the side wall of the housing (31) is provided with a sliding groove, the pin plate (34) slides horizontally with the sliding groove, and a limit plate is installed on the outside of the sliding groove.

[0012] This feature includes a sliding groove on the side wall of the housing (31), with the pin plate (34) sliding horizontally in cooperation with the sliding groove, so that the pin plate (34) can only slide horizontally in the direction defined by the sliding groove; a limiting plate is installed on the outside of the sliding groove to limit the displacement range of the pin plate (34) during the sliding process and prevent it from falling out of the sliding groove.

[0013] Preferably, a limiting steel ball is installed on the back of the locking knob (32), and two steel ball grooves are opened on the side wall of the housing (31), which are used to engage with the limiting steel ball when the locking knob (32) is locked and unlocked.

[0014] This setting includes a limiting steel ball (36) installed on the back of the locking knob (32), and two steel ball grooves are opened on the side wall of the housing (31). When the locking knob (32) is rotated to the locking or unlocking position, the limiting steel ball (36) will be inserted into the corresponding steel ball groove to form a snap-fit ​​and position the locking knob (32).

[0015] Preferably, the telescopic component (5) includes a mounting shell, the back of which is connected and fixed to the backrest plate (2), and the inner side of the mounting shell is provided with a fixed plate, a movable plate, and an X-shaped telescopic bracket. The X-shaped telescopic bracket is located between the fixed plate and the movable plate. The fixed plate is connected and fixed to the inner side of the mounting shell, and the movable plate is connected and fixed to the shell (31).

[0016] This telescopic component (5) includes a mounting shell (51), a fixed plate (52), a movable plate (53), and an X-shaped telescopic bracket (54). The back of the mounting shell (51) is fixedly connected to the backrest panel (2), the fixed plate (52) is fixedly connected to the inside of the mounting shell (51), the movable plate (53) is fixedly connected to the shell (31), and the X-shaped telescopic bracket (54) is located between the fixed plate (52) and the movable plate (53). When the relative position of the movable plate (53) and the fixed plate (52) changes, the X-shaped telescopic bracket (54) adapts to this change by telescopic deformation, thereby driving the mounting shell (51) and the backrest panel (2) connected to it to move back and forth.

[0017] Preferably, the four legs of the X-shaped telescopic bracket (54) are rotatably connected to guide plates via rotating shafts. Guide grooves are provided at both the upper and lower ends of the fixed plate (52) and the movable plate. The guide plates slide in cooperation with the guide grooves. The upper and lower rotating shafts of the X-shaped telescopic bracket (54) are tightened and fixed by tension springs, so that the X-shaped telescopic bracket (54) remains in an extended state.

[0018] The four legs of the X-shaped telescopic bracket (54) are rotatably connected to guide plates (541) via pivots (542). Guide grooves (55) are opened at the upper and lower ends of the fixed plate (52) and the movable plate (53). The guide plates (541) slide in the guide grooves (55). During the extension and retraction of the X-shaped telescopic bracket (54), the guide plates (541) slide in the guide grooves (55) to play a guiding role. The upper and lower pivots (542) of the X-shaped telescopic bracket (54) are tightened and fixed by tension springs (544) to keep the X-shaped telescopic bracket (54) in the extended state.

[0019] Preferably, anti-slip pads (543) are installed on both sides of the guide plate (541).

[0020] This feature involves installing anti-slip pads (543) on both sides of the guide plate (541) to increase the friction between the guide plate (541) and the guide groove (55).

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0022] This chair with adjustable backrest features a telescopic mechanism that allows the backrest to move back and forth, enabling flexible adjustment of its position. Whether you need to sit upright for work or relax and rest, you can adjust the backrest position to meet the diverse needs of different usage scenarios, significantly improving the chair's versatility compared to traditional fixed-back chairs.

[0023] The locking mechanism is designed to securely lock the telescopic components in place after they have returned to their original position. Specifically, rotating the locking knob activates a torsion spring, using leverage to lock and unlock the pin plate and pin hole. This locking method is stable and reliable, ensuring the backrest panel will not wobble or shift after being adjusted to a suitable position, thus guaranteeing user safety and comfort.

[0024] The X-shaped telescopic bracket in the telescopic component, together with the sliding structure of the guide plate and guide groove, remains extended under the action of the tension spring, making the telescopic adjustment process smooth and stable. At the same time, the anti-slip pads installed on both sides of the guide plate further enhance the stability during the telescopic process, preventing the backrest adjustment effect from being affected by poor sliding, and improving the convenience and comfort of user operation. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0026] Figure 2 This is a partial structural schematic diagram of the present invention;

[0027] Figure 3 This is a schematic diagram of the locking component in this utility model;

[0028] Figure 4 This is a schematic diagram of the locking knob in this utility model;

[0029] Figure 5 This is a schematic diagram of the telescopic component in this utility model;

[0030] Figure 6 This is a partial structural diagram of the telescopic component in this utility model;

[0031] The meanings of the labels in the diagram are as follows:

[0032] 1. Seat panel; 2. Backrest panel; 3. Locking component; 31. Housing; 32. Locking knob; 33. Torsion spring; 34. Pin plate; 35. Drive rod; 36. Limiting ball; 4. Decorative cover plate; 5. Telescopic component; 51. Mounting shell; 511. Pin hole; 52. Fixing plate; 53. Movable plate; 54. X-shaped telescopic bracket; 541. Guide plate; 542. Rotating shaft; 543. Anti-slip pad; 544. Tension spring; 55. Guide groove. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] This utility model provides a seat with backrest adjustment function, such as Figure 1 , Figure 2 , Figure 3 As shown, the device includes a seat panel 1, a backrest panel 2 installed on the inner side of the back of the seat panel 1, a locking component 3 installed between the backrest panel 2 and the seat panel 1, a telescopic component 5 installed in the middle of the locking component 3, one side of the telescopic component 5 connected to the backrest panel 2, and the other side of the telescopic component 5 connected to the locking component 3. The telescopic component 5 adjusts the front and back position of the backrest panel 2 by telescopic adjustment, and the locking component 3 is used to lock and fix the telescopic component 5 after it is reset.

[0035] A backrest panel 2 is installed on the inner side of the seat back 1, with a locking component 3 between them. A telescopic component 5 is installed in the middle of the locking component 3, and the telescopic component 5 is connected to both the backrest panel 2 and the locking component 3. By adjusting the telescopic component 5, its length is changed, thereby moving the backrest panel 2 back and forth. When the backrest panel 2 is adjusted to a suitable position, the locking component 3 resets and locks the telescopic component 5 to prevent the backrest panel 2 from shifting. This allows for flexible adjustment of the backrest panel 2's back position, meeting the diverse needs of users for backrest support in different usage scenarios, such as sitting upright while working or relaxing while resting. At the same time, the reliable locking mechanism ensures the stability of the adjusted backrest panel 2, improving the safety and comfort of the chair.

[0036] In this embodiment, as Figure 2 As shown, a decorative cover plate 4 is installed on the outer side of the back of the locking component 3.

[0037] A decorative cover plate 4 is installed on the outer side of the back of the locking component 3 to cover the back of the locking component 3. On the one hand, the decorative cover plate 4 can prevent dust and debris from entering the interior of the locking component 3, protect the parts of the locking component 3, extend its service life, and prevent the performance of the parts from being affected by dust and other impurities; on the other hand, it makes the overall appearance of the seat more beautiful and neat, and improves the quality and visual effect of the product.

[0038] Specifically, such as Figure 3 , Figure 4 As shown, the locking component 3 includes a housing 31. A locking knob 32 is rotatably connected to one side of the housing 31. A torsion spring 33 is installed on the shaft of the locking knob 32. A pin plate 34 is installed on the upper end of the torsion spring 33. A drive rod 35 is installed near the lower end of the locking knob 32 close to the torsion spring 33. A pin hole 511 is opened on one side of the outer wall of the telescopic component 5. When the locking knob 32 is rotated manually, it drives the lower end of the torsion spring 33 to move. Through the lever action, it drives the upper end of the torsion spring 33 to move, thereby realizing the locking and unlocking of the pin plate 34 and the pin hole 511.

[0039] The locking component 3 consists of a housing 31, a locking knob 32, a torsion spring 33, a pin plate 34, and a drive rod 35. When the locking knob 32 is manually rotated, the lower end of the torsion spring 33 moves. Since the upper end of the torsion spring 33 is equipped with the pin plate 34, leveraging the lever effect, the upper end of the torsion spring 33 drives the pin plate 34 to move. When the pin plate 34 is inserted into the pin hole 511 on one side of the outer wall of the telescopic component 5, the telescopic component 5 is locked. Reverse rotation of the locking knob 32 causes the pin plate 34 to be pulled out of the pin hole 511, unlocking the component. Locking and unlocking of the telescopic component 5 can be achieved simply by manually rotating the locking knob 32, making operation convenient. Furthermore, this locking method utilizing the lever principle and pin structure provides a stable and reliable fixing effect, ensuring that the backrest 2 will not sway or shift after adjustment.

[0040] Furthermore, the side wall of the housing 31 is provided with a sliding groove, the pin plate 34 slides horizontally with the sliding groove, and a limit plate is installed on the outside of the sliding groove.

[0041] A sliding groove is formed on the side wall of the housing 31, and the pin plate 34 slides horizontally with the sliding groove, so that the pin plate 34 can only slide horizontally in the direction defined by the sliding groove. A limiting plate is installed on the outside of the sliding groove to limit the displacement range of the pin plate 34 during the sliding process and prevent it from dislodging from the sliding groove. The movement trajectory of the pin plate 34 is standardized, ensuring that the pin plate 34 can be accurately inserted into or pulled out of the pin hole 511 under the action of the locking knob 32, which improves the accuracy and stability of the locking component 3 and avoids locking failure due to movement deviation of the pin plate 34.

[0042] Furthermore, a limiting steel ball 36 is installed on the back of the locking knob 32, and two steel ball grooves are opened on the side wall of the housing 31, which are used to engage with the limiting steel ball 36 when the locking knob 32 is locked and unlocked.

[0043] A limiting steel ball 36 is installed on the back of the locking knob 32, and two steel ball grooves are formed on the side wall of the housing 31. When the locking knob 32 is rotated to the locked or unlocked position, the limiting steel ball 36 will engage with the corresponding steel ball groove, forming a locking fit to position the locking knob 32. During the operation of the locking knob 32, clear operational feedback is provided, making it easy for the user to accurately determine whether the locking knob 32 is in the locked or unlocked state; at the same time, it prevents the locking knob 32 from rotating due to accidental contact, ensuring the reliability and stability of the backrest adjustment structure.

[0044] Furthermore, such as Figure 5 , Figure 6 As shown, the telescopic component 5 includes a mounting shell 51. The back of the mounting shell 51 is connected and fixed to the backrest plate 2. The inner side of the mounting shell 51 is provided with a fixed plate 52, a movable plate 53, and an X-shaped telescopic bracket 54. The X-shaped telescopic bracket 54 is located between the fixed plate 52 and the movable plate 53. The fixed plate 52 is connected and fixed to the inner side of the mounting shell 51, and the movable plate 53 is connected and fixed to the shell 31.

[0045] The telescopic component 5 includes a mounting shell 51, a fixed plate 52, a movable plate 53, and an X-shaped telescopic bracket 54. The back of the mounting shell 51 is fixedly connected to the backrest panel 2, the fixed plate 52 is fixed to the inner side of the mounting shell 51, the movable plate 53 is fixedly connected to the housing 31, and the X-shaped telescopic bracket 54 is located between the fixed plate 52 and the movable plate 53. When the relative position of the movable plate 53 and the fixed plate 52 changes, the X-shaped telescopic bracket 54 adapts to this change through telescopic deformation, thereby driving the mounting shell 51 and the connected backrest panel 2 to move back and forth. The structural design of the X-shaped telescopic bracket 54 enables smooth telescopic adjustment of the backrest panel 2; and the connection method between the fixed plate 52, the movable plate 53, the mounting shell 51, and the housing 31 ensures the overall structural stability of the telescopic component 5, making the backrest adjustment process smooth and reliable.

[0046] Furthermore, such as Figure 5 , Figure 6 As shown, guide plates 541 are rotatably connected to the four legs of the X-shaped telescopic bracket 54 via rotating shafts 542. Guide grooves 55 are provided at both the upper and lower ends of the fixed plate 52 and the movable plate 53. The guide plates 541 and the guide grooves 55 are slidably engaged. The upper and lower rotating shafts 542 of the X-shaped telescopic bracket 54 are tightened and fixed by tension springs 544, so that the X-shaped telescopic bracket 54 remains in an extended state.

[0047] The four legs of the X-shaped telescopic bracket 54 are rotatably connected to guide plates 541 via pivots 542. Guide grooves 55 are provided at the upper and lower ends of the fixed plate 52 and the movable plate 53. The guide plates 541 slide within the guide grooves 55, providing guidance during the extension and retraction of the X-shaped telescopic bracket 54. A tension spring 544 keeps the upper and lower pivots 542 of the X-shaped telescopic bracket 54 in a fixed, extended position. The sliding contact between the guide plates 541 and the guide grooves 55 provides stable guidance for the extension and retraction of the X-shaped telescopic bracket 54, ensuring a smooth and stable process and preventing shaking or jamming. The tension spring 544 keeps the X-shaped telescopic bracket 54 in an extended position, ensuring that the telescopic components 5 can respond to adjustment operations at any time during backrest adjustment, improving user convenience and comfort.

[0048] Furthermore, anti-slip pads 543 are installed on both sides of the guide plate 541.

[0049] Anti-slip pads 543 are installed on both sides of the guide plate 541 to increase the friction between the guide plate 541 and the guide groove 55. This further enhances the stability of the guide plate 541 when sliding in the guide groove 55, prevents poor sliding or abnormal displacement due to insufficient sliding friction, ensures the accuracy and reliability of the telescopic adjustment of the X-shaped telescopic bracket 54, and thus improves the overall performance of the backrest adjustment function.

[0050] When using the seat with backrest adjustment function of this utility model, the user first needs to perform an unlocking operation when adjusting the position of the seat back panel 2. The locking knob 32 in the locking component 3 is manually rotated. Since a torsion spring 33 is installed on the shaft of the locking knob 32, and a drive rod 35 is installed near the lower end of the torsion spring 33, rotating the locking knob 32 causes the lower end of the torsion spring 33 to move. Utilizing the lever principle, the upper end of the torsion spring 33 drives the pin plate 34 to move, causing the pin plate 34 to be pulled out from the pin hole 511 on the outer wall of one side of the telescopic component 5, thus unlocking the telescopic component 5. At this time, the limiting steel ball 36 disengages from the steel ball groove corresponding to the locked state and, with the rotation of the locking knob 32, engages with the steel ball groove corresponding to the unlocked state, providing the user with clear operational feedback indicating that unlocking has been completed.

[0051] After unlocking, the user can begin adjusting the position of the backrest 2. The X-shaped telescopic bracket 54 in the telescopic component 5 plays a crucial role. It is located between the fixed plate 52 and the movable plate 53. The fixed plate 52 is fixed to the inside of the mounting shell 51, and the movable plate 53 is connected and fixed to the shell 31. The back of the mounting shell 51 is also connected and fixed to the backrest 2. When the user pushes or pulls the backrest 2, the movable plate 53 and the fixed plate 52 are displaced relative to each other. The guide plates 541, which are rotatably connected to the four legs of the X-shaped telescopic bracket 54 via the pivot 542, slide within the guide grooves 55 opened at the upper and lower ends of the fixed plate 52 and the movable plate 53, thereby realizing the telescopic deformation of the X-shaped telescopic bracket 54 and driving the mounting shell 51 and the backrest 2 to move back and forth. During this process, the tension spring 544 between the two rotating shafts 542 of the X-shaped telescopic bracket 54 remains taut, keeping the X-shaped telescopic bracket 54 extended and ensuring a smooth and stable telescopic adjustment process. At the same time, the anti-slip pads 543 on both sides of the guide plate 541 increase the friction between the guide plate 541 and the guide groove 55, preventing the guide plate 541 from sliding abnormally and ensuring the accuracy of the adjustment.

[0052] After use, manually retract the X-shaped telescopic bracket 54 and manually rotate the locking knob 32 in the locking component 3 to insert the pin plate 34 into the pin hole 511 to lock the backrest panel 2.

[0053] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A seat with backrest adjustment function comprising a seat plate (1), characterized in that: A backrest panel (2) is installed on the inner side of the back of the seat panel (1). A locking component (3) is installed between the backrest panel (2) and the seat panel (1). A telescopic component (5) is installed in the middle of the locking component (3). One side of the telescopic component (5) is connected to the backrest panel (2), and the other side of the telescopic component (5) is connected to the locking component (3). The telescopic component (5) adjusts the front and back position of the backrest panel (2) by telescopic adjustment. The locking component (3) is used to lock and fix the telescopic component (5) after it is reset. The locking component (3) includes a housing (31), a locking knob (32) is rotatably connected to one side of the housing (31), a torsion spring (33) is installed on the shaft of the locking knob (32), a pin plate (34) is installed on the upper end of the torsion spring (33), a drive rod (35) is installed near the lower end of the locking knob (32) close to the torsion spring (33), and a pin hole (511) is opened on one side of the outer wall of the telescopic component (5). When the locking knob (32) is rotated manually, it drives the lower end of the torsion spring (33) to move, and drives the upper end of the torsion spring (33) to move through the lever action, so as to lock and unlock the pin plate (34) and the pin hole (511); The telescopic component (5) includes a mounting shell (51), the back of which is fixedly connected to the backrest panel (2). The inner side of the mounting shell (51) is provided with a fixed plate (52), a movable plate (53), and an X-shaped telescopic bracket (54). The X-shaped telescopic bracket (54) is located between the fixed plate (52) and the movable plate (53). The fixed plate (52) is fixedly connected to the inner side of the mounting shell (51), and the movable plate (53) is fixedly connected to the shell (31). The four legs of the X-shaped telescopic bracket (54) are rotatably connected to guide plates (541) via pivots (542). Guide grooves (55) are provided at both the upper and lower ends of the fixed plate (52) and the movable plate (53). The guide plates (541) slide with the guide grooves (55). The upper and lower pivots (542) of the X-shaped telescopic bracket (54) are tightened and fixed by tension springs (544) so ​​that the X-shaped telescopic bracket (54) remains in an extended state.

2. The seat with a backrest adjustment function according to claim 1, characterized in that: A decorative cover plate (4) is installed on the outer side of the back of the locking component (3).

3. The seat with a backrest adjustment function according to claim 1, characterized in that: The side wall of the housing (31) is provided with a sliding groove, the pin plate (34) slides horizontally with the sliding groove, and a limit plate is installed on the outside of the sliding groove.

4. The seat with a backrest adjustment function according to claim 1, characterized in that: The locking knob (32) has a limiting steel ball (36) installed on its back. The side wall of the housing (31) has two steel ball grooves, which are used to engage with the limiting steel ball (36) when the locking knob (32) is locked and unlocked.

5. The seat with a backrest adjustment function according to claim 1, characterized in that: Anti-slip pads (543) are installed on both sides of the guide plate (541).

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