Backrest lifting adjusting structure of wheelchair

Abstract

The utility model discloses a backrest lifting adjusting structure which at least comprises a left vertical rod and a right vertical rod of a backrest, a left vertical through hole and a right vertical through hole which correspond to each other are formed in a left side body and a right side body of a sliding component, and the left vertical rod and the right vertical rod which correspond to each other are correspondingly connected in a penetrating manner; the sliding part can only be adjusted in a vertical lifting sliding mode relative to the left vertical rod and the right vertical rod. The sliding component is used for adjusting the height of the wheelchair backrest; gear adjusting and positioning devices with different heights are arranged between the rod body of the left vertical rod and / or the rod body of the right vertical rod and the sliding part, and the gear adjusting and positioning devices are used for adjusting the height of the sliding part and positioning and fixing the sliding part; the product is provided with at least two left vertical rods and right vertical rods, so that the wheelchair backrest is supported more stably and firmly, and the situation that one side of the wheelchair backrest is turned over and twisted to be damaged due to overweight stress during use is prevented; the left vertical rod and the right vertical rod guide the sliding component to lift more stably; the sliding part can be adjusted in a larger lifting range relative to the left vertical rod and the right vertical rod, and a user can adjust and use conveniently.

Description

Technical Field

[0001] This utility model relates to wheelchair components, and more particularly to a backrest height adjustment structure for a wheelchair. Background Technology

[0002] 1. Chinese Patent Publication No. CN215779279U discloses a wheelchair backrest lifting and adjusting device, including a wheelchair body (1) and support columns (3) on both sides of the backrest panel (2) on the wheelchair body (1). There are two support columns (3), which are symmetrically distributed on both sides of the backrest panel (2). Lifting grooves (4) are provided on the side of the two support columns (3) away from the backrest panel (2). Lifting rods (5) are slidably connected in the lifting grooves (4), and lifting backrests (7) are fixedly connected between the two lifting rods (5). A trolley handle (8) is fixedly installed at the top of the lifting rod (5), and a lifting limiter is rotatably connected to the bottom. Structure (9); The lifting and limiting mechanism (9) includes a rotating rod (901) rotatably connected to the bottom section of the lifting rod (5). One end of the rotating rod (901) is fixedly connected to a limiting plate (902). A pull plate (903) and a spring (904) are respectively sleeved on the rotating rod (901). One end of the spring (904) is fixedly connected to the limiting plate (902), and the other end is fixedly connected to the pull plate (903). The pull plate (903) is arc-shaped, and the concave direction of the arc is set towards the limiting plate (902). Several slots (10) that cooperate with the rotating rod (901) are opened on the support column (3) along the height direction. The pull plate (903) has a contact flat opening on the side near the support column (3). The height of the lifting rod (5) is greater than the height of the support column (3). The number of slots (10) is at least two. The slot (10) on the support column (3) is located near the armrest of the wheelchair body (1). A head cushion (6) is attached to the lifting backrest (7). The diameter of the rotating rod (901) is smaller than the minimum width of the lifting slide (4).

[0003] After a period of use, the aforementioned lifting structure will experience mechanical wear, and the sliding lifting structure will become relatively loose, resulting in insufficient and unstable overall support for the backrest. The lifting structure will also become less robust and the lifting will be less stable.

[0004] 2. Chinese Patent Publication No. CN221308637U discloses a backrest height adjustment device for wheelchairs, belonging to the field of wheelchairs. It includes a backrest connecting device, a fixed base, and a height adjustment fixing device. The fixed base has a longitudinal hole, and the backrest connecting device is partially and movably inserted into the longitudinal hole, allowing it to be adjusted up and down within the hole. The height adjustment fixing device is movably connected between the backrest connecting device and the fixed base. The height adjustment fixing device is used to lock and unlock the backrest connecting device, fixing its height after raising / lowering. The height adjustment fixing device includes a screw and a rod hole. The rod hole is laterally opened on the rear wall of the fixed base and connects to the longitudinal hole. The screw is screwed through the rod hole. After the screw is unscrewed to separate the backrest connecting device, the backrest connecting device can be adjusted up and down within the longitudinal hole. After the screw is screwed in, the backrest connecting device is fixed at a fixed height. The backrest connection device includes a backrest connector and a lifting adjustment component. The top of the backrest connector is fixedly connected to the top of the lifting adjustment component, which is movably inserted into a longitudinal hole. After the screw is unscrewed to separate the lifting adjustment component, the lifting adjustment component can be adjusted up and down within the longitudinal hole, and the backrest connector moves up and down synchronously. After the screw is screwed in and inserted into the lifting adjustment component, the lifting adjustment component is fixed at a fixed height, thereby fixing the height of the backrest connector. The outer wall of the lifting adjustment component has several vertically arranged recessed stops. After the screw is unscrewed from the recessed stops to separate the lifting adjustment component, the lifting adjustment component can be adjusted up and down within the longitudinal hole. After the screw is screwed in and inserted into the recessed stops of the lifting adjustment component, the lifting adjustment component is fixed at a fixed height. The recessed stops are recessed steps or recessed holes. The longitudinal hole is a flat hole; the lifting adjustment component is a flat plate inserted into the flat hole. The backrest connector is fixedly connected to a wheelchair backrest. The backrest connection device, the fixing seat, and the lifting adjustment fixing device are made of metal. It also includes a central crossbar for the backrest, with a fixing bracket fixedly connected to the center of the central crossbar. Corresponding left and right backrest vertical bars are fixedly connected to the left and right ends of the central crossbar.

[0005] The lifting adjustment component of the aforementioned lifting adjustment and fixing device is relatively short, with a small range of lifting adjustment, making it inconvenient to use. Utility Model Content

[0006] To solve the above-mentioned technical problems, this utility model provides a backrest lifting and adjusting structure with a reasonable structural design, which makes the lifting and lowering of the wheelchair backrest stable, provides more stable and firm support for the wheelchair backrest, and makes the fixed connection of the wheelchair backrest, left vertical bar and right vertical bar more firm and sturdy.

[0007] The solution to the above technical problem is as follows:

[0008] A backrest height adjustment structure, belonging to wheelchair backrest components, includes at least a left vertical rod and a right vertical rod of the backrest, symmetrically arranged on both sides, and a sliding component. The sliding component has corresponding left and right vertical through holes on its left and right sides, which are designed to allow the corresponding left and right vertical rods to pass through. The sliding component can only slide up and down relative to the left and right vertical rods. The sliding component is used to adjust the height of the wheelchair backrest. Different height adjustment and positioning devices are provided between the left and / or right vertical rods and the sliding component, and these devices are used to adjust the height of the sliding component and for positioning and fixing it.

[0009] The beneficial effects of this utility model's wheelchair backrest height adjustment structure are as follows: 1. This product is equipped with at least two left and right vertical rods, which provide more stable and firm support for the wheelchair backrest. The fixed connection between the wheelchair backrest, left vertical rod, and right vertical rod is also more secure and robust, preventing the wheelchair backrest from tipping over and twisting due to excessive force on one side during use. The left and right vertical rods also provide smoother lifting and lowering for the guiding sliding component. 2. The left and right vertical rods do not require lifting or lowering. 3. The left and right vertical rods can be more easily equipped with adjustable positioning devices for a larger lifting and lowering range. The sliding component can have a larger lifting and lowering range relative to the left and right vertical rods, making it convenient for users to adjust. 4. By setting different height adjustment positioning devices between the left and / or right vertical rods and the sliding component, the lifting and lowering of the sliding component can be adjusted, thereby synchronously adjusting the lifting and lowering of the wheelchair backrest. This allows for easy adjustment of the wheelchair backrest height according to different heights and builds, achieving better sitting or reclining comfort, and making it more comfortable for the user's back to be against the wheelchair backrest. Attached Figure Description

[0010] Figure 1 This is a perspective view of the product of this utility model;

[0011] Figure 2 This is an exploded view of the left vertical rod, right vertical rod, and sliding component of the present invention.

[0012] Figure 3 , Figure 4 This is a perspective view of the product of this utility model;

[0013] Figure 5 This is an exploded view of the product of this utility model;

[0014] Figure 6 This is a cross-sectional view of the product of this utility model, showing the left vertical rod passing through the left vertical through hole without a gear adjustment and positioning component;

[0015] Figure 7 The cross-sectional view of the product of this utility model, in which the left vertical rod passes through the left vertical through hole and the gear adjustment and positioning component is a ball bearing structure;

[0016] Figure 8 The cross-sectional view of the product of this utility model, in which the left vertical rod passes through the left vertical through hole and the gear adjustment positioning component is a ball structure with a pressure spring;

[0017] Figure 9 The left vertical rod of this utility model is inserted into the left vertical through hole, and the gear adjustment and positioning component is a cross-sectional view of the locking rod structure.

[0018] Figure 10 yes Figure 7 Enlarged schematic diagram of part A;

[0019] Figure 11 yes Figure 8 Enlarged schematic diagram of part B;

[0020] Figure 12 yes Figure 9 Enlarged schematic diagram of part C;

[0021] Figure 13 This is a cross-sectional view of the product of this utility model, showing the right vertical rod passing through the right vertical through hole without a gear adjustment and positioning component;

[0022] Figure 14 The cross-sectional view of the right vertical rod of this utility model product passing through the right vertical through hole, and the gear adjustment and positioning component is a ball structure;

[0023] Figure 15 The cross-sectional view of the product of this utility model, in which the right vertical rod passes through the right vertical through hole and the gear adjustment positioning component is a ball structure with a pressure spring;

[0024] Figure 16 The right vertical rod of this utility model is inserted into the right vertical through hole, and the gear adjustment and positioning component is a cross-sectional view of the locking rod structure;

[0025] Figure 17 yes Figure 14 Enlarged schematic diagram of part D;

[0026] Figure 18 yes Figure 15 Enlarged schematic diagram of part E;

[0027] Figure 19 yes Figure 16 Enlarged schematic diagram of part F;

[0028] Figure 20 , Figure 21 This is a perspective view of the product of this utility model, including the backrest connecting seat and the wheelchair backrest.

[0029] Figure 22 , Figure 23 , Figure 24 , Figure 25This is a perspective view of the product of this utility model;

[0030] Figure 26 This is an exploded view of the product of this utility model;

[0031] Figure 27 This is a perspective view of the sliding seat of the present utility model.

[0032] Figure 28 , Figure 29 This is an exploded view of the product of this utility model;

[0033] Figure 30 This is a side view of the product of this utility model.

[0034] Left vertical rod 1, right vertical rod 2, sliding component 3, left vertical through hole 31, right vertical through hole 32, middle connecting seat 3A, left vertical tube 3B, horizontal rod 3C, right vertical tube 3D, gear adjustment and positioning device 4, gear hole 41, gear device mounting hole 42, gear adjustment and positioning component 43, ball seat 431, round ball 432, ball hole 433, pressure spring 434, locking rod 43A, backrest Connecting seat 5, shaft pin 501, wheelchair backrest 6, torsion spring 7, spring shaft 71, sliding seat 301, push button 402, pressing section 402A, tilting section 402B, lower vertical section 402C, slide groove 403, pin 404, return spring 405, rear recess 406, eaves plate 407, support plate 408, rod end through hole 409, plate through hole 410, rod body through hole 411, buckle hook 412. Detailed Implementation

[0035] like Figures 1-30The following describes a backrest height adjustment structure, belonging to wheelchair components. The structure includes at least a left vertical rod 1 and a right vertical rod 2, both made of metal tubing, such as aluminum or iron. The bottoms of the left and right vertical rods 1 and 2 are fixed to the wheelchair frame via screws or welding. The two vertical rods are symmetrically arranged horizontally and vertically. The structure also includes a sliding component 3, which synchronously drives the wheelchair backrest 6 to rise and fall. The sliding component 3 can be a single, integrally formed part or composed of multiple fixedly connected parts. The left and right sides of the sliding component 3... The main body has corresponding left vertical through holes 31 and right vertical through holes 32, which are just suitable for the corresponding left vertical rod 1 and right vertical rod 2 to pass through. The diameter of the left vertical rod 1 and right vertical rod 2 is 2 cm to 3 cm. The sliding component 3 can only slide up and down relative to the left vertical rod 1 and right vertical rod 2. The sliding component 3 is used to adjust the height of the wheelchair backrest 6. Different height adjustment and positioning devices 4 are provided between the rod body of the left vertical rod 1 and / or right vertical rod 2 and the sliding component 3. The height adjustment and positioning devices 4 are used to adjust the height of the sliding component 3 and fix its position. This product features at least two vertical bars, left 1 and right 2, providing more stable and secure support for the wheelchair backrest 6. The connection between the wheelchair backrest 6, left vertical bars 1, and right vertical bars 2 is also more robust and sturdy, preventing the wheelchair backrest 6 from tipping over or twisting due to excessive force on one side during use. The left vertical bars 1 and right vertical bars 2 ensure smoother raising and lowering of the guiding sliding component 3. By incorporating adjustable positioning devices 4 at different heights between the left vertical bar 1 and / or right vertical bar 2 and the sliding component 3, the raising and lowering of the sliding component 3 can be adjusted, thereby synchronously adjusting the raising and lowering of the wheelchair backrest 6. This allows for easy adjustment of the wheelchair backrest 6 to suit different heights and builds, achieving better sitting or reclining comfort, and ensuring a more comfortable backrest position.

[0036] Preferably: such as Figures 1-21As shown: The sliding component 3 includes a central connecting seat 3A, a left vertical tube 3B, a horizontal bar 3C, and a right vertical tube 3D. The left vertical tube 3B, horizontal bar 3C, and right vertical tube 3D are made of aluminum, iron, or steel. The left and right ends of the horizontal bar 3C are threaded through and fixedly connected to the corresponding left vertical tube 3B and right vertical tube 3D with screws. The interiors of the left vertical tube 3B and right vertical tube 3D have corresponding left vertical through holes 31 and right vertical through holes 32, respectively. The central connecting seat 3A is fixedly connected to the inner wall of the middle of the horizontal bar 3C with screws. The left vertical bar 1 is just right to pass through the left vertical through hole 31 of the left vertical tube 3B; the right vertical bar 2 is just right to pass through the right vertical tube 3D. The right vertical through hole 32 passes through; the above is a further specific structure of the sliding component 3. This structure increases the distance between the left vertical rod 1 and the right vertical rod 2. The distance is generally 35 cm to 45 cm, which facilitates the installation of the rear push handle on the top of the left vertical rod 1 and the right vertical rod 2. When a person lies back or leans against the backrest 6, it is more stable under pressure or gravity, which enhances the stability and firmness of the backrest 6. The left vertical tube 3B and the right vertical tube 3D are convenient to pass through the left vertical rod 1 and the right vertical rod 2. The left vertical rod 1 and the right vertical rod 2 are convenient to guide the left vertical tube 3B and the right vertical tube 3D to slide and rise. The gear adjustment and positioning device 4 is convenient to be set between the vertical rod and the vertical tube.

[0037] A gear adjustment and positioning device 4 is provided between the left vertical tube 3B and the body of the left vertical rod 1, or a gear adjustment and positioning device 4 is provided between the right vertical tube 3D and the body of the right vertical rod 2, or a gear adjustment and positioning device 4 is provided between the left vertical tube 3B and the body of the left vertical rod 1, and between the right vertical tube 3D and the body of the right vertical rod 2.

[0038] The above-mentioned setting of gear adjustment positioning device 4 on at least one of the left and right sides can realize the adjustment of the height of sliding component 3 and positioning fixation by gear adjustment positioning device 4. Alternatively, gear adjustment positioning device 4 can be set on both the left and right sides to realize the adjustment of the height of sliding component 3 and positioning fixation by gear adjustment positioning device 4. Setting on both sides is better, and the synchronization of both sides is better for balance and will not be biased to the side.

[0039] Preferably, the gear adjustment and positioning device 4 includes several gear holes 41 of different heights, gear device mounting holes 42, and gear adjustment and positioning components 43; the left vertical rod 1 or the right vertical rod 2 has several gear holes 41 of different heights, and the corresponding left vertical tube 3B or right vertical tube 3D has gear device mounting holes 42 in its wall. The gear adjustment and positioning components 43 are fixedly installed in the gear device mounting holes 42, and the inner end of the gear adjustment and positioning components 43 is embedded in the gear holes 41 of different heights to position and fix the sliding components 3 at different heights; the above describes the installation of the gear adjustment and positioning device 4 on one side of the left vertical rod 1 or the right vertical rod 2, and further refines the specific structure of the gear adjustment and positioning device 4. This structure is easy to set, easy to manufacture, easy to assemble, easy to use and easy to operate.

[0040] Preferably, the gear adjustment and positioning device 4 includes several gear holes 41 of different heights, gear device mounting holes 42, and gear adjustment and positioning components 43; the left vertical rod 1 and the right vertical rod 2 each have several gear holes 41 of different heights, and the corresponding left vertical tube 3B and right vertical tube 3D each have gear device mounting holes 42. Gear adjustment and positioning components 43 are fixedly installed in the gear device mounting holes 42 on both sides. The inner end of the gear adjustment and positioning component 43 is embedded in the gear holes 41 of different heights to position and fix the sliding component 3 at different heights; the left and right sides achieve synchronous lifting and lowering adjustment. There are generally three to eight gear holes 41.

[0041] Preferably, the gear adjustment and positioning component 43 includes a ball seat 431 and a round ball 432. The ball seat 431 and the round ball 432 are made of steel and are integrally formed. The ball seat 431 has a ball hole 433 on its front side, and a round ball 432 is placed in the ball hole 433. The round ball 432 protrudes outside the ball hole 433. Different gear holes 41 can be skipped in stages by the round ball 432. The protruding part of the round ball 432 is embedded in the gear hole 41 to fix the height of the sliding component 3. The ball seat 431 is embedded or fixed to the inner end of the gear device mounting hole 42 by a threaded structure. The above-mentioned gear adjustment and positioning component 43 has a simple structure and is easy to slide through, that is, it is relatively easy to skip gears. 40% of the body of the round ball 432 protrudes outside the ball hole 433 and 60% is inside the ball hole 433. 40% of the perfectly round ball bearing 432 protrudes into the vertical through hole, and 60% is placed inside the ball bearing hole 433. Most of the ball bearing is embedded in the ball bearing hole 433 to maintain the stability of sliding and preventing slippage. That is, 40% of the protruding perfectly round ball bearing 432 falls into / inserts into the stop hole 41, which can fix the left vertical tube 3B and the right vertical tube 3D in position. When adjusting the lifting, the left vertical tube 3B and the right vertical tube 3D can be pulled up or lowered with a little force. When in use, hold the horizontal bar 3C and lift with force. When pressed down, the middle connecting seat 3A, the left vertical tube 3B, and the right vertical tube 3D will rise or fall synchronously to adjust the height. The stop hole 41 will jump over the round ball 432. After the height is determined and the hand is released, the protruding part of the round ball 432 is embedded in the stop hole 41, fixing the height of the left vertical tube 3B and the right vertical tube 3D, thereby fixing the overall height of the sliding component 3. The above-mentioned stop adjustment and positioning component 43 is easy to manufacture and assemble, has good sliding performance, and the round ball will not cause wear to the left vertical tube 3B and the right vertical tube 3D.

[0042] Preferably, a pressure spring 434 is clamped between the inner bottom wall of the ball bearing hole 433 and the round ball bearing 432. The pressure spring 434 always pushes the round ball bearing 432 out, so that the round ball bearing 432 falls into / inserts into the stop hole 41 more properly. Even if it is a little loose after long-term use, it will not affect the use effect and the performance is better.

[0043] Preferably: such as Figure 16 , Figure 19 As shown: another structure of the gear adjustment and positioning component 43; the gear adjustment and positioning component 43 is a locking rod 43A, through which the locking rod 43A passes. The locking rod 43A and the gear hole 41 cooperate to adjust the sliding component 3 for sliding and positioning fixation; when the locking rod 43A is removed from the gear hole 41, the sliding component 3 can slide up and down relative to the left vertical rod 1 and the right vertical rod 2 for adjustment; the inner end of the locking rod 43A is inserted into the gear hole 41 to fix the height of the sliding component 3.

[0044] For example, the locking rod 43A is a threaded locking rod 43A, L-shaped, which is threaded through and screwed into the mounting hole 42 of the stop device. When the locking rod 43A is screwed inward, the inner end of the locking rod 43A is inserted into the stop hole 41 of the left vertical tube 3B and / or the right vertical tube 3D, and the sliding component 3 is positioned and fixed as a whole. When the locking rod 43A is screwed outward, the inner end of the locking rod 43A exits the stop hole 41 of the left vertical tube 3B and the right vertical tube 3D, and the sliding component 3 can slide up and down relative to the left vertical rod 1 and the right vertical rod 2. This structure is simple, practical and easy to operate.

[0045] Preferably, another structure of the gear adjustment positioning component 43 is provided; the gear adjustment positioning component 43 is an elastic locking pin (not shown in the figure), which cooperates with the gear hole 41 to adjust the sliding component 3 for sliding and positioning fixation.

[0046] Preferably, the middle connecting seat 3A is movably connected to the backrest connecting seat 5 via a shaft pin 501. The rear wall of the backrest connecting seat 5 and the front wall of the middle connecting seat 3A are connected by the shaft pin 501. The backrest connecting seat 5 can only be rotated back and forth relative to the middle connecting seat 3A. That is, a horizontal shaft hole is opened on the rear wall of the backrest connecting seat 5 and the front wall of the middle connecting seat 3A. The shaft pin 501 passes through the horizontal shaft hole, so that the middle connecting seat 3A is movably connected to the backrest connecting seat 5, so that the backrest connecting seat 5 can be rotated back and forth relative to the middle connecting seat 3A.

[0047] The front wall of the backrest connecting seat 5 is fixedly connected to the wheelchair backrest 6 with a screw assembly; a torsion spring 7 is clamped between the backrest connecting seat 5 and the middle connecting seat 3A. The torsion spring 7 is fixed to the middle connecting seat 3A through the spring shaft 71, so that the backrest connecting seat 5 is elastic and can automatically reset, so that the wheelchair backrest 6 can automatically reset to the specified optimal tilt angle when it is not pressed.

[0048] The above structure allows for easy adjustment of the tilt angle of the wheelchair backrest 6 to suit different people's back support activities; because some people's backs are wider and flatter, some are narrower and flatter, and some are more rounded; this makes the back support more comfortable.

[0049] Preferably: such as Figures 22-30 As shown: another structure of the sliding component 3; the sliding component 3 is a sliding seat 301, which is integrally injection molded. The left and right sides of the sliding seat 301 are provided with corresponding left vertical through holes 31 and right vertical through holes 32; the distance between the left vertical through holes 31 and right vertical through holes 32 is 5 cm to 10 cm; the sliding seat 301 can only be adjusted up and down relative to the left vertical rod 1 and right vertical rod 2; the sliding seat 301 is used to adjust the height of the wheelchair backrest 6; different height adjustment and positioning devices 4 are provided between the rod body of the left vertical rod 1 and / or the right vertical rod 2 and the sliding seat 301, and the position adjustment and positioning devices 4 are used to adjust the height of the sliding seat 301 and fix its position; the above structure can also realize the lifting and sliding and position adjustment and positioning fixation.

[0050] Preferably, another structure of the gear adjustment and positioning device 4 is as follows: the gear adjustment and positioning device 4 includes several gear holes 41 of different heights, push button 402, slide groove 403, pin 404, and return spring 405.

[0051] The right vertical rod 2 has several stop holes 41 of different heights on its body;

[0052] The rear wall of the sliding seat 301 has a rear recess 406. The top of the rear recess 406 extends into an eaves plate 407, and the bottom extends into a support plate 408. The middle of the rear recess 406 has a horizontally opened sliding groove 403. The rear wall of the sliding seat 301 has a horizontally opened rod end through hole 409. The rod end through hole 409 and the sliding groove 403 are horizontally connected. The eaves plate 407 has a plate through hole 410 that connects to the rear recess 406. The middle section of the pin 404 has a rod body through hole 411. The left and right inner walls of the rod body through hole 411 have inclined walls to allow the push button 402 to slide smoothly up and down.

[0053] The pin 404 is embedded in the slide groove 403 and lies flat. The right side of the pin 404 passes through the rod end through hole 409 and extends into the right vertical through hole 32. The right end of the pin 404 cooperates with several stop holes 41 of different heights to lock and unlock. The right end of the pin 404 is inserted into the stop holes 41 of different heights to position and fix the sliding seat 301 at different heights.

[0054] The push button 402 is integrally formed and vertically arranged; the push button 402 includes a pressing section 402A, an inclined section 402B, and a lower vertical section 402C;

[0055] The push button 402 is arranged longitudinally, passing through the plate through hole 410 and the rod through hole 411. The pressing section 402A is connected to the plate through hole 410, and the tilting section 402B is connected to the rod through hole 411. The pressing section 402A protrudes from the top of the eaves board 407. The outer slope of the tilting section 402B is adapted to the inner slope of the rod through hole 411. The lower vertical section 402C is connected to the support plate 408 by a top-pressing return spring 405. Under normal conditions, the push button 402 is pushed up by the return spring 405, and the tilting section 402B pushes the pin 404 to the left, so that the left end of the pin 404 is inserted into the stop hole 41 to position and fix the height of the sliding seat 301.

[0056] The sliding seat 301 is movably connected to the backrest connecting seat 5 via a shaft pin 501. The rear wall of the backrest connecting seat 5 and the front wall of the sliding seat 301 are connected by the shaft pin 501. The backrest connecting seat 5 can only be rotated back and forth relative to the sliding seat 301. That is, a horizontal shaft hole is opened on the rear wall of the backrest connecting seat 5 and the front wall of the sliding seat 301. The shaft pin 501 passes through the horizontal shaft hole, so that the sliding seat 301 is movably connected to the backrest connecting seat 5, so that the backrest connecting seat 5 can be rotated back and forth relative to the sliding seat 301. The rotation angle is generally 0 degrees to 45 degrees. The front wall of the backrest connecting seat 5 is fixedly connected to the wheelchair backrest 6 with a screw assembly.

[0057] The above describes another structure of the gear adjustment positioning device 4. This gear adjustment positioning device 4 can automatically reset and lock, facilitating operation. This structure cooperates with the sliding seat 301. By vertically pressing the push button 402 to lower it, the return spring 405 resets, causing the push button 402 to rise. The tilting section 402B of the push button 402, during its up-and-down movement, causes a misalignment, pushing the pin 404 to move left and right. When the push button 402 lowers, the return spring 405 is compressed, and the tilting section 402B of the push button 402 pushes the pin 404 to the left and right. The movement exits the stop hole 41, allowing the sliding seat 301 to be pulled up and down to adjust its height. The sliding seat 301 slides up and down relative to the left vertical rod 1 and the right vertical rod 2, and the backrest connecting seat 5 and the wheelchair backrest 6 rise and fall synchronously. After the height is determined, the push button 402 is released, and the return spring 405 returns to its original position, causing the push button 402 to rise. The inclined section 402B of the push button 402 pushes the pin 404 to move to the right and insert it into the stop hole 41, thereby fixing the height of the sliding seat 301. Therefore, the height of the backrest connecting seat 5 and the wheelchair backrest 6 is fixed. The pressing section 402A is integrally extended with a buckle hook 412. The buckle hook 412 is long and elastic, and it passes through the plate through hole 410, and is prevented from falling off by the eaves plate 407.

Claims

1. A backrest height adjustment structure, belonging to wheelchair backrest components, the backrest height adjustment structure including at least a left vertical rod and a right vertical rod of the backrest, the two vertical rods being symmetrically arranged left and right, characterized in that: It also includes a sliding component; the left and right sides of the sliding component have corresponding left and right vertical through holes, which are just suitable for the corresponding left and right vertical rods to pass through; the sliding component can only slide up and down relative to the left and right vertical rods; the sliding component is used to adjust the height of the wheelchair backrest; different height adjustment and positioning devices are provided between the left and / or right vertical rods and the sliding component, and the adjustment and positioning devices are used to adjust the height of the sliding component and fix its position.

2. The backrest height adjustment structure according to claim 1, characterized in that: The sliding component includes a central connecting seat, a left vertical tube, a crossbar, and a right vertical tube. The left and right ends of the crossbar are fixedly connected to the corresponding left and right vertical tubes. The interiors of the left and right vertical tubes are corresponding left and right vertical through holes. The central connecting seat is fixedly connected to the inner wall of the middle of the crossbar. A gear adjustment and positioning device is provided between the left vertical tube and the left vertical rod, or between the right vertical tube and the right vertical rod, or both the left vertical tube and the left vertical rod, and the right vertical tube and the right vertical rod are equipped with gear adjustment and positioning devices.

3. The backrest height adjustment structure according to claim 2, characterized in that: The gear adjustment and positioning device includes several gear holes of different heights, gear device mounting holes, and gear adjustment and positioning components. The left or right vertical rod has several gear holes of different heights, and the corresponding left or right vertical tube has a gear device mounting hole in its wall. A gear adjustment and positioning component is fixedly installed in the gear device mounting hole. The inner end of the gear adjustment and positioning component is embedded in the gear holes of different heights to position and fix the sliding component at different heights.

4. The backrest height adjustment structure according to claim 3, characterized in that: The gear adjustment and positioning component includes a ball seat and a round ball. The ball seat has a ball hole on its front side, and a round ball is placed in the ball hole. The round ball protrudes outside the ball hole. Different gear holes can be adjusted by the round ball. The protruding part of the round ball is embedded in the gear hole to fix the height of the sliding component. The ball seat is embedded or fixed to the inner end of the gear device mounting hole by a threaded structure.

5. The backrest height adjustment structure according to claim 3, characterized in that: The gear adjustment and positioning component is a locking rod. The locking rod passes through the gear device mounting hole. The locking rod and the gear hole cooperate to adjust the sliding component for sliding and positioning. When the locking rod is removed from the gear hole, the sliding component can slide up and down relative to the left and right vertical rods for adjustment. The inner end of the locking rod is inserted into the gear hole to fix the height of the sliding component.

6. A backrest height adjustment structure according to any one of claims 2 to 5, characterized in that: The middle connecting seat is movably connected to the backrest connecting seat via a shaft pin. The rear wall of the backrest connecting seat and the front wall of the middle connecting seat are connected by the shaft pin. The backrest connecting seat can only be rotated back and forth relative to the middle connecting seat.

7. The backrest height adjustment structure according to claim 6, characterized in that: The axle pin is connected by a torsion spring, and the torsion spring is clamped between the backrest connecting seat and the middle connecting seat; the front wall of the backrest connecting seat is fixedly connected to a wheelchair backrest.

8. The backrest height adjustment structure according to claim 1, characterized in that: The sliding component is a sliding seat, with corresponding left and right vertical through holes on its left and right sides. The sliding seat can only be adjusted up and down relative to the left and right vertical rods. The sliding seat is used to adjust the height of the wheelchair backrest. Different height adjustment and positioning devices are provided between the left and / or right vertical rods and the sliding seat. The height adjustment and positioning devices are used to adjust the height of the sliding seat and fix its position.

9. The backrest height adjustment structure according to claim 8, characterized in that: The gear adjustment and positioning device includes several gear holes of different heights, push buttons, slides, locking rods, and return springs; The right vertical rod has several stop holes of different heights on its shaft; The rear wall of the sliding seat has a recessed portion, the top of which extends into an eaves plate and the bottom of which extends into a support plate. A sliding groove is provided in the middle of the recessed portion. The rear wall of the sliding seat has a rod end through hole provided in the middle. The rod end through hole and the sliding groove are horizontally arranged. The eaves plate has a plate through hole that connects to the recessed portion. A rod body through hole is provided on the middle section of the locking rod. The locking rod is embedded in the sliding groove and laid flat. The right side of the locking rod passes through the rod end through hole and extends into the right vertical through hole. The right end of the locking rod cooperates with several stop holes of different heights to lock and unlock. The right end of the locking rod is inserted into stop holes of different heights to position and fix the sliding seat at different heights. The push button is integrally formed; the push button includes a pressing section, an tilting section, and a lower vertical section; The push button is arranged longitudinally, passing through the through hole of the plate and the through hole of the rod. The pressing section passes through the through hole of the plate, and the tilting section passes through the through hole of the rod. The pressing section protrudes from the top of the eaves board, and the outer slope of the tilting section matches the inner slope of the through hole of the rod. A top-pressing return spring is connected between the lower vertical section and the support plate.

10. A backrest height adjustment structure according to claim 8 or 9, characterized in that: The sliding seat is movably connected to the backrest connecting seat via a shaft pin. The rear wall of the backrest connecting seat and the front wall of the sliding seat are connected by the shaft pin. The backrest connecting seat can only be rotated back and forth relative to the sliding seat.

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