Suspension chair
By using a detachable fixing mechanism and a conveniently operable sunshade and item placement structure, the problem of traditional suspended chairs being space-consuming and having limited functionality has been solved, thus improving portability and practicality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- QINGDAO HAIBODA NEW MATERIALS CO LTD
- Filing Date
- 2025-04-24
- Publication Date
- 2026-05-15
AI Technical Summary
Traditional hover chairs take up a lot of space, are not easy to carry, and have limited functionality, making them difficult to meet the needs of outdoor use scenarios.
A foldable suspended chair was designed, which achieves portability and functional expansion through a control structure with detachable fixing mechanism, sunshade and item placement components.
The suspended chair is foldable to reduce its footprint, making it easy to carry. It also provides sunshade and multiple storage compartments, enhancing its convenience and practicality for outdoor use.
Smart Images

Figure CN224235019U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of outdoor products, specifically relating to a suspension chair. Background Technology
[0002] The principle of a suspension chair is based on a tension structure, where the seat is fixed to a base by a combination of ropes. Suspension chairs are characterized by their exquisite and aesthetically pleasing structure, low cost, and reduced weight, making movement easier. They offer an excellent user experience at home. In recent years, due to the popularity of outdoor activities, their sophisticated structure has also made them a promising option in the outdoor market. However, traditional suspension chairs are space-consuming and inconvenient to carry outdoors, and their limited functionality does not suit outdoor use scenarios; therefore, structural improvements are needed. Utility Model Content
[0003] To address the aforementioned issues, this invention proposes a suspended chair. Users can operate the sunshade via the telescopic ends of the armrests, or adjust the backrest using the control lines. The chair also allows for the use of a foot pedal to control the item placement mechanism. This convenient design greatly enhances the user experience, and the sunshade and item placement mechanisms are better suited for outdoor environments.
[0004] Specific solution: A suspension chair, including a support, a seat, and a fixing mechanism.
[0005] The support includes a suspension end extending toward the seat, and the seat includes a connecting portion extending toward the support, with the suspension end being higher than the connecting portion;
[0006] The fixing mechanism includes suspension fixing components and suspension stabilizers; the suspension fixing components are connected between the suspension end and the connecting part to fix the seat; at least three suspension stabilizers are evenly distributed on the outer edge of the seat and connected to the support to stabilize the seat.
[0007] The fixing mechanism and seat are detachably connected.
[0008] Furthermore, the seat includes a connecting seat, a backrest, armrests, and a seat fabric; the backrest and the connecting seat are rotatably connected, the armrests are fixed to the connecting seat, and the seat fabric extends from the backrest to the edge of the connecting seat.
[0009] Furthermore, a limiting component is provided at the connection between the backrest and the connecting seat. The limiting component includes a rotating gear, a limiting block, and a control line. A rotating seat is fixed to the connecting seat, and the rotating gear is fixed to the backrest. The rotating gear and the rotating seat are rotatably connected. An elastic component is provided at the connection between the two. The limiting block and the rotating seat are elastically connected by a spring and engage with the rotating gear. The control line is connected to the limiting block.
[0010] When storing, disassemble the fixing mechanism, rotate the backrest to fit with the connecting seat, and then reverse the support to fit with the connecting seat. This can greatly reduce the space occupied and improve portability.
[0011] Furthermore, a sunshade is provided above the seat, which includes a canopy and a control unit; the canopy is fixed to the seat, and the control unit is connected to the canopy and controls the canopy to unfold or fold.
[0012] The addition of sunshades allows the hover chair to be shielded from direct sunlight when used outdoors, making it more suitable for outdoor settings.
[0013] Furthermore, the canopy includes a frame and a canopy. The frame is arc-shaped, and the two ends of multiple frames are connected to the rotation points on both sides of the seat. Multiple frames are evenly distributed and connected to the canopy.
[0014] The canopy and seat are rotatably connected, allowing the canopy to be folded. When stored, the canopy can also be rotated away from the user to fit the backrest.
[0015] The backrest is equipped with a fixing claw. When the suspension chair is in the non-folded state but the sunshade is in the folded state, the last rib of the canopy is fixed to the fixing claw, and the control component is fixed to the first rib. When the control component pulls the canopy to unfold, the last rib of the canopy remains fixed so that the canopy can unfold.
[0016] The fixing claws are set to slide relative to the backrest. When the canopy needs to be stored, the fixing claws slide to release the fixing to the canopy frame.
[0017] Furthermore, the control components include unfolding lines and folding lines, which are connected to one side of the canopy in opposite directions. The unfolding lines extend to the front of the seat, and the folding lines are connected to multiple canopy ribs one by one. The folding lines are elastic lines.
[0018] The unfolding line is fixed to the first rib of the canopy, and the folding line is fixed sequentially from the first rib to the last rib and then extends to the rear of the seat and is fixed to the connecting seat.
[0019] When the tent needs to be unfolded, pull the unfolding line to rotate the first rib forward. The tent will gradually unfold under the action of the tarpaulin. When it needs to be folded, loosen the unfolding line. The folding line will rotate the rib backward under the action of elasticity until they are close together.
[0020] Furthermore, the handrail is equipped with a wire channel, and the front end of the handrail is equipped with a telescopic end. The telescopic end slides relative to the handrail, and the unfolded wire passes through the wire channel and is connected to the telescopic end.
[0021] The unfolding line is located inside the handrail. To unfold the sunshade, the telescopic end is pulled away from the canopy, i.e., in front of the user. The unfolding line moves forward, and the canopy unfolds. There is a positioning piece between the telescopic end and the handrail to restrict the movement of the telescopic end. Releasing the positioning piece will reset the telescopic end, allowing the canopy to fold.
[0022] Users can control the unfolding of the sunshade without getting up or sitting down, which improves the ease of use.
[0023] Furthermore, the control line passes through the wiring channel of another handrail and connects to the telescopic end.
[0024] Furthermore, the side of the seat is provided with an item placement component, which includes at least two tabletops. The item placement component is slidably connected to the seat, and a lifting component is connected to the item placement component to control the raising and lowering of the item placement component.
[0025] The item placement area can be placed next to the armrest, which greatly increases the space for placing items. Users can place their mobile phones, water, snacks or other items on the item placement area while sitting in the suspended chair, which greatly improves the practicality.
[0026] The item placement unit has two layers, and the lifting mechanism moves the item placement unit up and down so that both layers can be at a suitable height.
[0027] Furthermore, the front of the seat is equipped with a pedal, which is connected to a lifting mechanism. When the pedal moves down, the lifting mechanism lifts the item placement component.
[0028] The footrest allows users to place their feet, improving the comfort of the suspension chair. Connecting the footrest to the lifting mechanism allows the lifting mechanism to be powered by foot pedals, enabling users to control the raising and lowering of the item placement device without getting up. This makes it convenient and comfortable to use, enhancing the user experience.
[0029] Furthermore, a sliding track is provided between the item placement component and the seat. The sliding track includes a groove and a slider. The groove is provided on the item placement component and the seat. The slider has a positioning groove. The seat has a locking component. The locking component and the positioning groove cooperate to fix the slider.
[0030] The lifting mechanism and the sliding channel work together to control the lifting of the item placement component. When the locking mechanism fixes the item placement component, the lifting mechanism is also fixed.
[0031] Furthermore, the lifting component includes a connecting rope and a fixed pulley. The fixed pulley is fixed to the seat above the item placement component. One end of the connecting rope is connected to the pedal, and the other end passes through the fixed pulley and is connected to the item placement component.
[0032] The fixed pulley is fixed to the handrail, and the connecting rope is connected to the bottom of the item placement part so that when the end of the connecting rope reaches the fixed pulley, the lower part of the item placement part can be raised to a suitable height.
[0033] The beneficial effects of this utility model are as follows:
[0034] (1) The suspension chair of this application is foldable, and the fixing mechanism and the seat are detachable, which reduces the space occupied and improves portability.
[0035] (2) The suspended chair of this application has a sunshade function. Users can control the sunshade by sitting on the seat and using the armrests without getting up, which improves the user experience.
[0036] (3) The suspended chair of this application is equipped with a storage piece, which increases the storage capacity of the suspended chair, making it more suitable for outdoor scenarios and improving its practicality.
[0037] (4) The floating chair of this application can control the placement of items and switch the desktop by stepping on the foot pedal, which is convenient and quick to use and improves the comfort of use. Attached Figure Description
[0038] The accompanying drawings, which are provided to further illustrate this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application.
[0039] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model;
[0040] Figure 2 This is a schematic diagram of the structure of an embodiment of the present utility model;
[0041] Figure 3 This is a schematic diagram of the structure of the item placement component and the lifting component in an embodiment of this utility model;
[0042] Figure 4 for Figure 3 Enlarged view of the locking component at point A;
[0043] Figure 5 This is a schematic diagram of the limiting component structure in an embodiment of the present utility model;
[0044] Figure 6 This is a schematic diagram of the storage state according to an embodiment of the present utility model;
[0045] In the attached diagram: 1-support, 11-suspension end, 2-seat, 21-connector, 22-connector seat, 221-rotating seat, 23-backrest, 24-armrest, 241-telescopic end, 242-wire channel, 25-seat fabric, 26-limiting component, 261-rotating gear, 262-limiting block, 263-control line, 3-fixing mechanism, 31-suspension fixing component, 32-suspension stabilizing component, 4-sunshade component, 41-canopy body, 411-canopy frame, 412-canopy fabric, 42-control component, 421-unfolding line, 422-folding line, 5-item placement component, 51-lifting component, 511-connecting rope, 512-fixed pulley, 52-sliding track, 521-slide groove, 522-slider, 523-positioning groove, 53-locking component, 6-pedal. Detailed Implementation
[0046] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.
[0047] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.
[0048] Furthermore, it should be understood in the description of this application that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.
[0049] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0050] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.
[0051] like Figure 1-6 As shown, a suspension chair includes a support 1, a seat 2, and a fixing mechanism 3.
[0052] The support 1 includes a suspension end 11 extending toward the seat 2, and the seat 2 includes a connecting part 21 extending toward the support 1, with the suspension end 11 being higher than the connecting part 21.
[0053] The fixing mechanism 3 includes a suspension fixing member 31 and a suspension stabilizing member 32; the suspension fixing member 31 is connected between the suspension end 11 and the connecting part 21 and is used to fix the seat 2; at least three suspension stabilizing members 32 are evenly distributed on the outer edge of the seat 2 and connected to the support 1 to stabilize the seat 2.
[0054] The fixing mechanism 3 and the seat 2 are detachably connected, and both the suspension fixing component 31 and the suspension stabilizing component 32 are ropes.
[0055] In one specific embodiment, such as Figure 1-2 As shown, the seat 2 includes a connecting seat 22, a backrest 23, an armrest 24, and a seat fabric 25; the backrest 23 and the connecting seat 22 are rotatably connected, the armrest 24 is fixed to the connecting seat 22, and the seat fabric 25 extends from the backrest 23 to the edge of the connecting seat 22.
[0056] When storing, such as Figure 6 As shown, the fixing mechanism 3 can be disassembled, the backrest 23 can be rotated to fit with the connecting seat 22, and the support 1 can be reversed and fitted with the connecting seat 22. This can greatly reduce the space occupied and improve portability.
[0057] In one specific embodiment, such as Figure 5As shown, a limiting member 26 is provided at the connection between the backrest 23 and the connecting seat 22. The limiting member 26 includes a rotating gear 261, a limiting block 262, and a control line 263. A rotating seat 221 is fixed to the connecting seat 22. The rotating gear 261 is fixed to the backrest 23. The rotating gear 261 and the rotating seat 221 are rotatably connected. The limiting block 262 is elastically connected to the rotating seat 221 and engages with the rotating gear 261. The control line 263 is connected to the limiting block 262.
[0058] In one specific embodiment, such as Figure 1-2 As shown, a sunshade 4 is provided above the seat 2. The sunshade 4 includes a canopy 41 and a control component 42. The canopy 41 is fixed to the seat 2. The control component 42 is connected to the canopy 41 and controls the canopy 41 to unfold or fold.
[0059] The installation of sunshade component 4 allows the suspension chair to be shielded from sunlight when used outdoors, reducing direct sunlight and making the suspension chair more suitable for outdoor scenarios.
[0060] In one specific embodiment, such as Figure 1-2 As shown, the canopy body 41 includes canopy ribs 411 and canopy cloth 412. The canopy ribs 411 are arc-shaped, and the two ends of multiple canopy ribs 411 are respectively connected to the rotation points on both sides of the seat 2. Multiple canopy ribs 411 are evenly distributed and connected to the canopy cloth 412.
[0061] The canopy 41 and the seat 2 are rotatably connected, so that the canopy 41 can be folded. When stored, the canopy 41 can also be rotated away from the user to fit the backrest 23.
[0062] The backrest 23 is equipped with a fixing claw. When the suspension chair is in the non-folded state but the sunshade 4 is in the folded state, the last rib 411 of the canopy body 41 is fixed to the fixing claw, and the control member 42 is fixed to the first rib 411. When the control member 42 pulls the canopy body 41 to unfold, the last rib 411 of the canopy body 41 is fixed in place so that the canopy body 41 can unfold.
[0063] The fixing claw is slidably set relative to the backrest 23. When the canopy 41 needs to be stored, the fixing claw slides to cancel the fixing of the canopy frame 411.
[0064] In one specific embodiment, such as Figure 1-2 As shown, the control component 42 includes an unfolding line 421 and a folding line 422. The unfolding line 421 and the folding line 422 are connected to one side of the canopy 41 in opposite directions. The unfolding line 421 extends to the front of the seat 2, and the folding line 422 is connected to multiple canopy ribs 411 one by one. The folding line 422 is an elastic line.
[0065] The unfolding line 421 is fixed to the first rib 411 of the canopy body 41, and the folding line 422 is fixed sequentially from the first rib 411 to the last rib 411 and then extends to the rear of the seat 2 and is fixed to the connecting seat 22.
[0066] When the canopy 41 needs to be unfolded, the unfolding line 421 is pulled to make the first canopy frame 411 rotate forward. Under the action of the tarpaulin 412, the canopy 41 gradually unfolds. When it needs to be folded, the unfolding line 421 and the folding line 422 are released. Under the action of elasticity, the canopy frame 411 will rotate backward until they are close together.
[0067] In one specific embodiment, such as Figure 6 As shown, the handrail 24 has a wire channel 242 inside, and a telescopic end 241 at the front end of the handrail 24. The telescopic end 241 slides relative to the handrail 24, and the unfolded line 421 passes through the wire channel 242 and is connected to the telescopic end 241.
[0068] The unfolding line 421 is located inside the handrail 24. To unfold the sunshade 4, the telescopic end 241 is stretched away from the canopy 41, i.e., in front of the user. The unfolding line 421 then moves forward, and the canopy 41 unfolds. A positioning element is provided between the telescopic end 241 and the handrail 24 to restrict the movement of the telescopic end 241. By releasing the positioning element, the telescopic end 241 can be reset, allowing the canopy 41 to fold.
[0069] Users can control the unfolding of the sunshade 4 without getting up or sitting down, which improves the ease of use.
[0070] In one specific embodiment, the control line 263 passes through the wire channel 242 of another handrail 24 and connects to the telescopic end 241.
[0071] In one specific embodiment, such as Figure 2-3 As shown, the side of the seat 2 is provided with an item placement component 5, which includes at least two tabletops. The item placement component 5 and the seat 2 are slidably connected. The item placement component 5 is connected to a lifting component 51, which controls the lifting of the item placement component 5.
[0072] The item placement piece 5 can be placed next to the armrest 24. The item placement piece 5 greatly increases the space for placing items, allowing users to place their mobile phones, water, snacks or other items on the item placement piece while sitting in the floating chair, which greatly improves the practicality.
[0073] The item placement component 5 has two layers. The lifting component 51 drives the item placement component 5 to rise and fall so that both layers can be located at a suitable height.
[0074] In one specific embodiment, the front end of the seat 2 is provided with a pedal 6, which is connected to a lifting member 51. When the pedal 6 moves down, the lifting member 51 drives the item placement member 5 to rise.
[0075] One end of the pedal 6 is connected to the lifting component 51, and the other end is fixed to the handrail 24 by an elastic rope.
[0076] The pedal 6 allows users to place their feet, improving the comfort of the suspension chair. By connecting the pedal 6 to the lifting component 51, the lifting component 51 can be powered by foot pedals. Users can control the lifting of the item placement component 5 without getting up, making it convenient and comfortable to use and improving the user experience.
[0077] In one specific embodiment, such as Figure 4 As shown, a sliding track 52 is provided between the item placement component 5 and the seat 2. The sliding track 52 includes a groove 521 and a slider 522. The groove 521 is provided on the item placement component 5 and the seat 2. The slider 522 is provided with a positioning groove 523. The seat 2 is provided with a locking component 53. The locking component 53 and the positioning groove 523 cooperate to fix the slider 522.
[0078] The lifting component 51 and the sliding channel work together to control the lifting of the item placement component 5. When the locking component 53 fixes the item placement component 5, the lifting component 51 is also fixed.
[0079] The locking member 53 is a clamp. When fixed, the locking member 53 clamps the positioning groove 523 to achieve relative fixation between the locking member 53 and the slider 522, so that the item placement member 5 cannot move.
[0080] In one specific embodiment, such as Figure 3 As shown, the lifting component 51 includes a connecting rope 511 and a fixed pulley 512. The fixed pulley 512 is fixed to the seat 2 above the item placement component 5. One end of the connecting rope 511 is connected to the pedal 6, and the other end passes through the fixed pulley 512 and is connected to the item placement component 5.
[0081] The fixed pulley 512 is fixed to the handrail 24, and the connecting rope 511 is connected to the bottom of the item placement part 5 so that when the end of the connecting rope 511 reaches the fixed pulley 512, the lower part of the item placement part 5 can be raised to a suitable height.
[0082] When in use, the user sits on seat 2. When the user wants to use the sunshade 4, they pull the telescopic end 241 of the armrest 24. The unfolding line 421 is pulled forward, causing the canopy rib 411 to unfold, and the telescopic end 241 is fixed by the positioning piece. When the sunshade 4 is not in use, the positioning piece is opened, and the sunshade 4 folds under the elasticity of the folding line 422. When the user wants to adjust the angle of the backrest 23, they pull the telescopic end 241 of the other armrest 24 to disengage the limiting block 262 and the rotating gear 261. At this time, the spring at the limiting block 262 is stretched, and pushing it backward allows the backrest 23 to be adjusted backward. Removing the pushing force allows the backrest 23 to be adjusted forward. When adjusted to the desired angle... After reaching the appropriate position, release the telescopic end 241, allowing the limiting block 262 to re-engage with the rotating gear 261 under the action of elasticity to complete the fixation. Next to the handrail 24, there is an item placement piece 5 for placing items. The item placement piece 5 has upper and lower layers. When you want to use the lower layer, open the locking piece 53, step down on the pedal 6, and the lifting piece 51 will pull the item placement piece 5 up. Then close the locking piece 53, so that the locking piece 53 and the positioning groove 523 engage to fix the item placement piece 5. When retracting the lower layer, open the locking piece 53, and the item placement piece 5 will reset under the action of gravity and elastic rope. Then close the locking piece 53 again to use the pedal 6 and the item placement piece 5 normally.
[0083] When storing the suspension chair, remove the fixing mechanism 3, rotate the backrest 23 towards the connecting seat 22, rotate the sunshade 4 towards the backrest 23, flip the support 1 over and place it on the seat 2, and use the connecting rope 511 at the foot pedal 6 to fix the two together, and the storage is complete.
[0084] For any parts not mentioned in this application, existing technologies may be used or referenced.
[0085] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.
[0086] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.
Claims
1. A suspension chair, comprising a support, a seat, and a fixing mechanism, characterized in that, The support includes a suspension end extending toward the seat, the seat includes a connecting portion extending toward the support, and the suspension end is higher than the connecting portion; The fixing mechanism includes a suspension fixing component and a suspension stabilizing component; the suspension fixing component is connected between the suspension end and the connecting part to fix the seat; at least three suspension stabilizing components are evenly distributed on the outer edge of the seat and connected to the support to stabilize the seat.
2. A suspension chair according to claim 1, characterized in that, The seat includes a connecting seat, a backrest, armrests, and a seat fabric; the backrest and the connecting seat are rotatably connected, the armrests are fixed to the connecting seat, and the seat fabric extends from the backrest to the edge of the connecting seat.
3. A suspension chair according to claim 2, characterized in that, A sunshade is provided above the seat. The sunshade includes a canopy and a control component. The canopy is fixed to the seat, and the control component is connected to the canopy and controls the canopy to unfold or fold.
4. A suspension chair according to claim 3, characterized in that, The canopy includes a frame and a canopy. The frame is arc-shaped, and the two ends of multiple frames are respectively connected to the rotation points on both sides of the seat. Multiple frames are evenly distributed and connected to the canopy.
5. A suspension chair according to claim 4, characterized in that, The control element includes an unfolding line and a folding line, which are connected to one side of the canopy in opposite directions. The unfolding line extends to the front of the seat, and the folding line is connected to a plurality of canopy ribs in sequence. The folding line is an elastic line.
6. A suspension chair according to claim 5, characterized in that, The handrail has a wire channel inside, and the front end of the handrail has a telescopic end that slides relative to the handrail. The unfolded line passes through the wire channel and is connected to the telescopic end.
7. A suspension chair according to claim 1, characterized in that, The seat has a side panel for placing items. The side panel includes at least two tabletops. The side panel is slidable relative to the seat. The side panel is connected to a lifting mechanism, which controls the raising and lowering of the side panel. The seat has a pedal at the front end, and the lifting component is connected to the pedal. When the pedal moves down, the lifting component causes the item placement component to rise.
8. A suspension chair according to claim 7, characterized in that, A sliding track is provided between the item placement component and the seat. The sliding track includes a groove and a slider. The groove is located on the item placement component and on the seat. The slider has a positioning groove. The seat has a locking component. The locking component and the positioning groove cooperate to fix the slider.
9. A suspension chair according to claim 7, characterized in that, The lifting component includes a connecting rope and a fixed pulley. The fixed pulley is fixed to the seat above the item placement component. One end of the connecting rope is connected to the pedal, and the other end passes through the fixed pulley and is connected to the item placement component.
10. A suspension chair according to claim 2, characterized in that, A limiting component is provided at the connection between the backrest and the connecting seat. The limiting component includes a rotating gear, a limiting block, and a control line. A rotating seat is fixed to the connecting seat. The rotating gear is fixed to the backrest. The rotating gear and the rotating seat are rotatably connected. The limiting block is elastically connected to the rotating seat and engages with the rotating gear. The control line is connected to the limiting block.