Self-weight chassis adjusting structure
Patent Information
- Application Number
- CN202522187786.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-16
- Publication Date
- 2026-09-25
- Estimated Expiration
- 2035-10-16
AI Technical Summary
但现有调节装置中的弹簧组件，其弹性力参数一经设定便无法改变；鉴于升降座椅使用人群在年龄、性别、体力等方面存在较大差异，这种不可调节的弹性力设置，导致不同用户难以获得理想的调节体验；例如，当弹簧组件弹性力度设定过大时，体力较弱的用户，如老年人、儿童或体质较弱的成年人，在推动靠背调节角度时，会因难以克服强大的弹性阻力而面临操作困难；反之，若弹簧组件弹性力度设置过小，体力充沛的青壮年用户在调节靠背时，可能会因阻力不足，导致靠背瞬间后倾，不仅容易破坏身体平衡，引发安全隐患，而且靠背过快的倾倒速度，使得其难以精准定位到目标角度，用户往往需要反复调整，操作过程繁琐且耗时，极大影响了使用的便捷性与舒适性
[0013]本实用新型的有益效果是：本实用新型中，中间座上的弹簧力度调节手柄与弹簧力度调节部件之间传动连接。当用户转动弹簧力度调节手柄时，弹簧力度调节部件同步动作，并通过改变弹性部件两端的间距来调整其预紧力。当弹性部件两端距离减小时，弹性部件的预紧力增大，靠背调节过程中压缩弹性部件所需克服的弹性阻力增强，调节时阻力感增大，即增大了弹簧部件的弹性力度。反之，增大间距时，弹性部件的预紧力减小，调节时阻力感增大，从而减小了弹簧部件的弹性力度。用户可根据自身体力需求，通过转动弹簧力度调节手柄，驱动弹簧力度调节部件改变弹性部件的初始形变量（预紧力），从而完成弹性部件阻力参数的设定，满足不同用户的需求。
Smart Images
Figure CN224791945U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of seat technology, and in particular to a self-weighting chassis adjustment structure. Background Technology
[0002] Existing height-adjustable seats typically include components such as an adjustment mechanism, backrest, cylinder, seat, and chassis. The bottom of the cylinder is connected to the chassis, and the top of the cylinder is connected to the adjustment mechanism. The backrest and seat are also connected to the adjustment mechanism. The adjustment mechanism controls the cylinder and adjusts the seat height, while also adjusting the backrest angle.
[0003] In terms of seat adjustment device design, existing technologies mostly adopt a combination of a base, a rocker arm, and a base plate. The rocker arm and the base are rotatably connected to achieve relative movement, while the backrest is fixedly connected to the rocker arm, with a spring assembly between them to provide elastic support. Furthermore, a locking mechanism mounted on the base can lock the rotation angle of the rocker arm, ensuring the stability of the seat during use. In actual operation, if the user needs to adjust the backrest angle, they must first unlock the rocker arm through the locking mechanism, allowing it to rotate freely relative to the base; then, using their own back strength, they push the backrest to adjust it to the appropriate angle; finally, they re-engage the locking mechanism to fix the rocker arm, thus keeping the backrest stably at the target angle. However, when adjusting the backrest angle, users need to overcome the elastic resistance generated by the spring assembly. But the elastic force parameters of the spring assembly in existing adjustment devices cannot be changed once set. Given the significant differences in age, gender, and physical strength among users of height-adjustable seats, this non-adjustable elastic force setting makes it difficult for different users to obtain an ideal adjustment experience. For example, when the spring assembly's elastic force is set too high, users with weaker physical strength, such as the elderly, children, or adults with weaker constitutions, will face operational difficulties when adjusting the backrest angle due to the strong elastic resistance. Conversely, if the spring assembly's elastic force is set too low, strong young and middle-aged users may experience insufficient resistance when adjusting the backrest, causing the backrest to tilt backward instantly. This not only easily disrupts body balance and poses a safety hazard, but also makes it difficult to accurately position the target angle, often requiring repeated adjustments. This cumbersome and time-consuming process greatly affects the convenience and comfort of use. Summary of the Invention
[0004] The purpose of this invention is to address the shortcomings of existing technologies and provide a self-supporting chassis adjustment structure.
[0005] The purpose of this utility model is achieved through the following technical solution: a self-supporting chassis adjustment structure, including a middle seat, a base plate, a connecting plate, and a rocker. The rocker is connected to the middle seat via a first shaft, and the connecting plate is connected to the middle seat via a hinge shaft. The rocker is connected to the base plate via a second shaft, and the connecting plate is connected to the base plate via a fourth shaft. A spring force adjustment component and a spring force adjustment handle are provided on the middle seat, and the spring force adjustment handle and the spring force adjustment component are connected by a transmission connection. An elastic component is provided between the spring force adjustment component and the connecting plate. When the rocker rotates, it drives the connecting plate to rotate relative to the middle seat. When the spring force adjustment handle rotates, it drives the spring force adjustment component to change the distance between the two ends of the elastic component.
[0006] Preferably, a third shaft is provided on the intermediate seat; the spring force adjustment component includes a first connecting arm, a second connecting arm, an adjusting push block, an adjusting cam, a fifth shaft, a sixth shaft, a seventh shaft, and a second spring seat. The fifth and sixth shafts are rotatably connected to the intermediate seat. An adjusting cam is provided on the fifth shaft, and an adjusting push block is provided on the sixth shaft. The adjusting cam contacts the adjusting push block. One end of the second connecting arm is rotatably connected to the adjusting push block, and the other end of the second connecting arm is rotatably connected to the seventh shaft. One end of the first connecting arm is connected to the third shaft, and the other end of the first connecting arm is rotatably connected to the seventh shaft. The second spring seat is connected to the seventh shaft. A first spring seat corresponding to the second spring seat is provided on the connecting plate, and both ends of the elastic component are connected to the first spring seat and the second spring seat, respectively. A transmission mechanism is provided between the spring force adjustment handle and the fifth shaft.
[0007] Preferably, the transmission mechanism includes a first gear connected to the fifth shaft and a second gear connected to the spring force adjustment handle, wherein the first gear and the second gear mesh.
[0008] Preferably, the adjusting cam has several contact surfaces arranged in the circumferential direction.
[0009] Preferably, the intermediate seat is provided with a lifting adjustment mechanism, which includes a lifting adjustment block, a lifting adjustment handle, and a lifting adjustment rod. The lifting adjustment handle is provided with a first swing arm. One end of the lifting adjustment block is rotatably connected to a first shaft, and the other end of the lifting adjustment block is a pressure end. One end of the lifting adjustment rod is connected to the first swing arm on the lifting adjustment handle, and the other end of the lifting adjustment rod is connected to the lifting adjustment block. The intermediate seat is provided with a lifting cylinder connection hole, and the pressure end of the lifting adjustment block is located above the lifting cylinder connection hole.
[0010] Preferably, the lifting adjustment handle is sleeved on the spring force adjustment handle, and the lifting adjustment handle sleeve and the spring force adjustment handle are rotatably engaged.
[0011] Preferably, the device also includes an angle locking mechanism for locking the rocker angle; the angle locking mechanism includes a locking adjustment handle, a gear plate, a torsion spring, a locking block, and a locking lever; the gear plate is connected to the rocker and rotates synchronously with the rocker; the gear plate is provided with several gear holes; the intermediate seat is provided with a torsion spring limiting screw, the torsion spring is sleeved on the torsion spring limiting screw, the locking block is slidably connected to the intermediate seat and corresponds to the gear holes on the gear plate; the locking adjustment handle is provided with a second swing arm, one end of the locking lever is connected to the second swing arm, the other end of the locking lever is connected to one end of the torsion spring, and the other end of the torsion spring is connected to the locking block.
[0012] Preferably, the intermediate seat is provided with a limiting surface for limiting the second shaft.
[0013] The beneficial effects of this utility model are as follows: In this utility model, the spring force adjustment handle on the middle seat is connected to the spring force adjustment component via a transmission connection. When the user rotates the spring force adjustment handle, the spring force adjustment component moves synchronously and adjusts its preload by changing the distance between the two ends of the elastic component. When the distance between the two ends of the elastic component decreases, the preload of the elastic component increases, the elastic resistance that needs to be overcome to compress the elastic component during backrest adjustment increases, and the resistance during adjustment increases, thus increasing the elastic force of the spring component. Conversely, when the distance increases, the preload of the elastic component decreases, the resistance during adjustment increases, and thus the elastic force of the spring component decreases. Users can adjust the resistance parameters of the elastic component by rotating the spring force adjustment handle according to their own physical needs, thereby driving the spring force adjustment component to change the initial deformation (preload) of the elastic component and thus meeting the needs of different users. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the structure of this utility model.
[0015] Figure 2 This is a schematic diagram of the structure of this utility model after the bottom plate is removed.
[0016] Figure 3 This is an exploded view of the present invention.
[0017] Figure 4 This is a schematic diagram of the structure of the intermediate seat.
[0018] Figure 5 This is a schematic diagram of the spring force adjustment component.
[0019] Figure 6 This is a cross-sectional view of the spring force adjustment component.
[0020] Figure 7 This is a schematic diagram of the angle locking mechanism.
[0021] Figure 8 This is a schematic diagram of the gear shift panel.
[0022] Figure 9 This is a schematic diagram of the present invention when adjusting the spring force.
[0023] In the diagram: 1. Base plate; 2. Intermediate seat; 2-1. Limiting surface; 2-2. Lifting cylinder connection hole; 3. Connecting plate; 4. Rocker; 5. Locking adjustment handle; 6. Spring force adjustment handle; 7. Lifting adjustment handle; 8. Lifting adjustment block; 9. Lifting adjustment rod; 10. First shaft; 11. Second shaft; 12. Third shaft; 13. Fourth shaft; 14. Hinge shaft; 15. Bushing; 16. First spring seat; 17. Elastic component; 18. Adjusting shaft; 20. Gear. Position plate, 20-1, gear hole, 21, spring force adjustment component, 21-1, adjustment push block, 21-2, first connecting arm, 21-3, second spring seat, 21-4, adjustment cam, 21-5, fifth shaft, 21-6, first gear, 21-7, second gear, 21-8, sixth shaft, 21-9, seventh shaft, 21-10, second connecting arm, 22, locking lever, 25, second swing arm, 26, locking block, 27, torsion spring limit screw, 28, torsion spring. Detailed Implementation
[0024] 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model are within the protection scope of the present utility model.
[0025] like Figures 1 to 9 As shown, the self-supporting chassis adjustment structure includes an intermediate seat 2, a base plate 1, a connecting plate 3, and a rocker 4. The rocker 4 is connected to the intermediate seat 2 via a first shaft 10, and the connecting plate 3 is connected to the intermediate seat 2 via a hinge shaft 14. The rocker 4 is connected to the base plate 1 via a second shaft 11, and the connecting plate 3 is connected to the base plate 1 via a fourth shaft 13. The intermediate seat 2 is provided with a spring force adjustment component 21 and a spring force adjustment handle 6, which are connected by a transmission connection. An elastic component 17 is provided between the spring force adjustment component 21 and the connecting plate 3. When the rocker 4 rotates, it causes the connecting plate 3 to rotate relative to the intermediate seat 2. When the spring force adjustment handle 6 rotates, it causes the spring force adjustment component 21 to move to change the distance between the two ends of the elastic component 17.
[0026] The four components—intermediate seat 2, base plate 1, connecting plate 3, and rocker 4—are connected by shafts, allowing rotation between adjacent components. These four components form a four-bar linkage. The seat of the adjustable chair is fixedly connected to the base plate 1, and the backrest is connected to the rocker 4. The rocker 4 rotates around the first shaft 10. When adjusting the backrest angle, the rocker 4 rotates around the first shaft 10. During this rotation, the rocker 4, under the restraint of the base plate 1, causes relative rotation between the connecting plate 3 and the intermediate seat 2, thereby causing corresponding deformation of the elastic component 17.
[0027] The spring force adjustment handle 6 on the middle seat 2 is connected to the spring force adjustment component 21 via a transmission mechanism. When the user rotates the spring force adjustment handle 6, the spring force adjustment component 21 moves synchronously, adjusting the preload by changing the distance between the two ends of the elastic component 17. When the distance between the two ends of the elastic component 17 decreases, the preload of the elastic component 17 increases, the elastic resistance that needs to be overcome to compress the elastic component 17 during backrest adjustment increases, and the resistance during adjustment increases, thus increasing the elastic force of the spring component. Conversely, when the distance increases, the preload of the elastic component 17 decreases, the resistance during adjustment increases, and thus the elastic force of the spring component decreases.
[0028] Users can adjust the resistance parameters of the elastic component 17 by rotating the spring force adjustment handle 6, which drives the spring force adjustment component 21 to change the initial deformation (preload) of the elastic component 17 according to their own physical strength needs, thereby meeting the needs of different users. For example, the resistance can be appropriately reduced for the elderly, while the resistance can be appropriately increased for young adults. In this application, the elastic component 17 is a helical spring.
[0029] Specifically, a third shaft 12 is provided on the intermediate seat 2; the spring force adjustment component 21 includes a first connecting arm 21-2, a second connecting arm 21-3, an adjusting push block 21-1, an adjusting cam 21-4, a fifth shaft 21-5, a sixth shaft 21-8, a seventh shaft 21-9, and a second spring seat 21-3. The fifth shaft 21-5 and the sixth shaft 21-8 are rotatably connected to the intermediate seat 2. The fifth shaft 21-5 is provided with an adjusting cam 21-4, and the sixth shaft 21-8 is provided with an adjusting push block 21-1. The adjusting cam 21-4 contacts the adjusting push block 21-1; the second connecting arm... One end of the second connecting arm 21-3 is rotatably connected to the adjusting push block 21-1, and the other end of the second connecting arm 21-3 is rotatably connected to the seventh shaft 21-9; one end of the first connecting arm 21-2 is connected to the third shaft 12, and the other end of the first connecting arm 21-2 is rotatably connected to the seventh shaft 21-9; the second spring seat 21-3 is connected to the seventh shaft 21-9; the connecting plate 3 is provided with a first spring seat 16 corresponding to the second spring seat, and both ends of the elastic component 17 are connected to the first spring seat 16 and the second spring seat 21-3 respectively; a transmission mechanism is provided between the spring force adjusting handle 6 and the fifth shaft 21-5.
[0030] The transmission mechanism includes a first gear 21-6 connected to the fifth shaft 21-5 and a second gear 21-7 connected to the spring force adjustment handle 6, wherein the first gear 21-6 and the second gear 21-7 mesh.
[0031] When the user rotates the spring force adjustment handle 6, the second gear 21-7, coaxially connected to the spring force adjustment handle 6, rotates synchronously. This gear, through the meshing first gear 21-6, drives the fifth shaft 21-5 to rotate, thus transmitting the power of the spring force adjustment handle 6 to the fifth shaft 21-5. The rotation of the fifth shaft 21-5 causes the adjustment cam 21-4 to rotate synchronously. The adjustment push block 21-1 contacts the contour surface of the adjustment cam 21-4. The rotation of the adjustment cam 21-4 drives the adjustment push block 21-1 to rotate. The rotation of the adjustment push block 21-1 forces the first connecting arm 21-2 and the second connecting arm 21-3 to rotate. This rotation changes the position of the seventh shaft 21-9, thereby changing the position of the second spring seat 21-3. This changes the distance between the two ends of the elastic component 17 (spring), and consequently changes the preload of the elastic component 17. This allows for personalized settings of the backrest adjustment force.
[0032] The adjusting cam 21-4 has several contact surfaces arranged circumferentially. The introduction of these contact surfaces transforms the adjusting cam 21-4 from a continuous curve drive to a stepping planar drive, enabling geared rotation angle control. When the adjusting handle drives the adjusting cam 21-4 to rotate, the contact surfaces of the adjusting cam 21-4 sequentially contact the adjusting push block 21-1; each contact surface corresponds to a fixed angular position of the adjusting cam 21-4. For example, when the adjusting cam 21-4 is a hexahedral cam, it has six contact surfaces arranged circumferentially. Rotating by a certain angle, the adjusting push block 21-1 will complete one gear shift, and the preload of the elastic component 17 corresponds to a fixed gear. When the adjusting push block 21-1 is in contact with a certain contact surface on the adjusting cam 21-4, the adjusting cam 21-4 can be stably maintained at the current angle position in the non-adjusting state through the action of the contact surface, and the adjusting cam 21-4 will not rotate randomly.
[0033] A lifting adjustment mechanism is provided on the intermediate seat 2. The lifting adjustment mechanism includes a lifting adjustment block 8, a lifting adjustment handle 7, and a lifting adjustment rod 9. A first swing arm is provided on the lifting adjustment handle 7. One end of the lifting adjustment block 8 is rotatably connected to the first shaft 10, and the other end of the lifting adjustment block 8 is the pressure end. One end of the lifting adjustment rod 9 is connected to the first swing arm on the lifting adjustment handle 7, and the other end of the lifting adjustment rod 9 is connected to the lifting adjustment block 8. A lifting cylinder connection hole 2-2 is provided on the intermediate seat 2, and the pressure end of the lifting adjustment block 8 is located above the lifting cylinder connection hole 2-2.
[0034] When the user rotates the height adjustment handle 7, the first swing arm also rotates, and the rotational motion of the first swing arm is converted into axial tension or thrust through the height adjustment lever 9. The two ends of the height adjustment lever 9 are hinged to the first swing arm and the height adjustment block 8, respectively. Under the pulling action of the height adjustment lever 9, the height adjustment block 8 is driven to rotate around the first axis 10. When the height adjustment block 8 rotates around the first axis 10, the pressure end will rotate downward. The upper end of the height adjustment cylinder of the height adjustment seat is inserted into the height adjustment cylinder connector. The upper end of the height adjustment cylinder is provided with a height control lever for triggering the height adjustment action of the cylinder. The downward rotation of the pressure end will press and trigger the height control lever on the top of the cylinder component, thereby controlling the height adjustment of the height adjustment cylinder and realizing the height adjustment function of the entire seat.
[0035] The lifting adjustment handle 7 is mounted on the spring force adjustment handle 6, and the lifting adjustment handle 7 and the spring force adjustment handle 6 are in rotational engagement.
[0036] This utility model also includes an angle locking mechanism for locking the angle of the rocker 4. The angle locking mechanism includes a locking adjustment handle 5, a stop plate 20, a torsion spring 28, a locking block 26, and a locking pull rod 22. The stop plate 20 is connected to the rocker 4 and rotates synchronously with the rocker 4. The stop plate 20 is provided with a plurality of stop holes 20-1. The intermediate seat 2 is provided with a torsion spring limiting screw 27, and the torsion spring 28 is sleeved on the torsion spring limiting screw 27. The locking block 26 is slidably connected to the intermediate seat 2 and corresponds to the stop holes 20-1 on the stop plate 20. The locking adjustment handle 5 is provided with a second swing arm 25. One end of the locking pull rod 22 is connected to the second swing arm 25, and the other end of the locking pull rod 22 is connected to one end of the torsion spring 28. The other end of the torsion spring 28 is connected to the locking block 26.
[0037] The locking adjustment handle 5 is hinged to the locking lever 22 via the second swing arm 25, forming a conversion from handle rotation to linear tension; the torsion spring 28 is sleeved on the torsion spring limiting screw 27 of the intermediate seat 2, one end is connected to the locking lever 22, and the other end is fixed to the locking block 26, using the torsion spring 28 as an intermediate component to drive the locking block 26 to slide; the gear plate 20 is fixed on the rocker plate 4 and rotates synchronously with the rocker plate 4, and the gear hole 20-1 on it corresponds to the position of the locking block 26, forming a locking interface. During the unlocking operation, the user rotates the locking adjustment handle 5 in one direction. The locking adjustment handle 5 drives the second swing arm 25 to rotate, which in turn drives the locking rod to pull one end of the torsion spring 28 to rotate. The torsion spring 28 is pulled and stores elastic potential energy, which pulls the locking block 26 out of the gear position hole 20-1 on the gear position plate 20. This releases the locking block 26 from the gear position hole 20-1, thereby unlocking the rocker 4 and allowing it to rotate freely, thus adjusting the angle of the backrest. During the locking operation, the user releases the locking adjustment handle 5. The elastic potential energy of the torsion spring 28 is released, pushing the locking block 26 towards the gear position plate 20. This allows the locking block 26 to insert into the gear position hole 20-1 at the current position, locking the gear position plate 20 and restricting the rotation of the rocker 4, thus locking the angle of the backrest. The intermediate seat 2 is provided with a limiting surface 2-1 for limiting the second shaft 11. A bushing 15 is provided on the second shaft 11 at a position corresponding to the limiting surface 2-1.
[0038] This utility model is not limited to the above-described preferred embodiments. Anyone can derive other forms of products under the guidance of this utility model. However, regardless of any changes made in their shape or structure, any technical solution that is the same as or similar to this application falls within the protection scope of this utility model.
Claims
1. A self-supporting chassis adjustment structure, characterized in that, It includes a middle seat, a base plate, a connecting plate, and a rocker. The rocker is connected to the middle seat via a first shaft, and the connecting plate is connected to the middle seat via a hinge shaft. The rocker is connected to the base plate via a second shaft, and the connecting plate is connected to the base plate via a fourth shaft. The middle seat is equipped with a spring force adjustment component and a spring force adjustment handle, and the spring force adjustment handle is connected to the spring force adjustment component via a transmission connection. An elastic component is provided between the spring force adjustment component and the connecting plate. When the rocker rotates, it causes the connecting plate to rotate relative to the middle seat. When the spring force adjustment handle rotates, it causes the spring force adjustment component to move to change the distance between the two ends of the elastic component.
2. The self-supporting chassis adjustment structure according to claim 1, characterized in that, A third shaft is provided on the intermediate seat; the spring force adjustment component includes a first connecting arm, a second connecting arm, an adjusting push block, an adjusting cam, a fifth shaft, a sixth shaft, a seventh shaft, and a second spring seat. The fifth and sixth shafts are rotatably connected to the intermediate seat. An adjusting cam is provided on the fifth shaft, and an adjusting push block is provided on the sixth shaft. The adjusting cam contacts the adjusting push block. One end of the second connecting arm is rotatably connected to the adjusting push block, and the other end of the second connecting arm is rotatably connected to the seventh shaft. One end of the first connecting arm is connected to the third shaft, and the other end of the first connecting arm is rotatably connected to the seventh shaft. The second spring seat is connected to the seventh shaft; a first spring seat corresponding to the second spring seat is provided on the connecting plate, and the two ends of the elastic component are respectively connected to the first spring seat and the second spring seat; a transmission mechanism is provided between the spring force adjustment handle and the fifth shaft.
3. The self-supporting chassis adjustment structure according to claim 2, characterized in that, The transmission mechanism includes a first gear connected to the fifth shaft and a second gear connected to the spring force adjustment handle, with the first gear meshing with the second gear.
4. The self-supporting chassis adjustment structure according to claim 2, characterized in that, The adjusting cam has several contact surfaces arranged circumferentially.
5. The self-supporting chassis adjustment structure according to claim 1, characterized in that, The intermediate seat is provided with a lifting adjustment mechanism, which includes a lifting adjustment block, a lifting adjustment handle, and a lifting adjustment rod. The lifting adjustment handle is provided with a first swing arm. One end of the lifting adjustment block is rotatably connected to a first shaft, and the other end of the lifting adjustment block is a pressure end. One end of the lifting adjustment rod is connected to the first swing arm on the lifting adjustment handle, and the other end of the lifting adjustment rod is connected to the lifting adjustment block. The intermediate seat is provided with a lifting cylinder connection hole, and the pressure end of the lifting adjustment block is located above the lifting cylinder connection hole.
6. The self-supporting chassis adjustment structure according to claim 5, characterized in that, The lifting adjustment handle is sleeved on the spring force adjustment handle, and there is a rotational engagement between the lifting adjustment handle sleeve and the spring force adjustment handle.
7. The self-supporting chassis adjustment structure according to claim 1, characterized in that, It also includes an angle locking mechanism for locking the rocker angle; the angle locking mechanism includes a locking adjustment handle, a gear plate, a torsion spring, a locking block, and a locking lever. The gear plate is connected to the rocker and rotates synchronously with the rocker. The gear plate is provided with several gear holes. The intermediate seat is provided with a torsion spring limiting screw, and the torsion spring is sleeved on the torsion spring limiting screw. The locking block is slidably connected to the intermediate seat and corresponds to the gear holes on the gear plate. The locking adjustment handle is provided with a second swing arm. One end of the locking lever is connected to the second swing arm, the other end of the locking lever is connected to one end of the torsion spring, and the other end of the torsion spring is connected to the locking block.
8. The self-supporting chassis adjustment structure according to claim 1, characterized in that, The intermediate seat is provided with a limiting surface for limiting the second shaft.