Folding device and wheelchair

Abstract

The application discloses a folding device and a wheelchair, and belongs to the technical field of folding. The folding device is arranged between a seat and a frame of the wheelchair, and comprises a connecting rod mechanism and a driving mechanism. One end of the connecting rod mechanism is arranged in rotation connection with the seat, and the other end of the connecting rod mechanism is arranged in rotation connection with the frame. The driving mechanism is an automatic driving mechanism, one end of the driving mechanism is arranged in rotation connection with one of the seat and the frame, and the other end of the driving mechanism is arranged in transmission connection with the connecting rod mechanism, so as to drive the connecting rod mechanism to move relative to the frame, and make the seat close to or away from the frame. The above scheme can solve the problem that the folding wheelchair in the related art is complex in operation.

Description

Technical Field

[0001] This application belongs to the field of folding technology, specifically relating to a folding device and a wheelchair. Background Technology

[0002] Wheelchairs are commonly used for home rehabilitation, transportation, medical visits, and outdoor activities for the injured, sick, or disabled. To facilitate storage after use or to minimize the space they occupy, wheelchairs are typically designed to be foldable.

[0003] Wheelchairs are typically folded manually, where the operator presses on the seat or other parts of the wheelchair to fold it. However, this method is relatively complicated and can lead to a poor user experience.

[0004] In summary, the folding wheelchairs involved in the relevant technologies have the problem of being relatively complex to operate. Utility Model Content

[0005] This application discloses a folding device and a wheelchair to solve the problem that the operation of folding wheelchairs involved in related technologies is relatively complicated.

[0006] To solve the above-mentioned technical problems, this application adopts the following technical solution: A folding device for mounting between the seat and frame of a wheelchair, the folding device comprising a linkage mechanism and a drive mechanism. One end of the linkage mechanism is rotatably connected to the seat, and the other end of the linkage mechanism is rotatably connected to the frame. The drive mechanism is an automatic drive mechanism, and one end of the drive mechanism is rotatably connected to either the seat or the frame, while the other end of the drive mechanism is drively connected to the linkage mechanism to drive the linkage mechanism to move relative to the frame, so that the seat moves closer to or away from the frame.

[0007] A wheelchair includes a seat, a frame, and the aforementioned folding device, the folding device being mounted between the seat and the frame.

[0008] The technical solution adopted in this application can achieve the following beneficial effects: In this application, the linkage mechanism is rotatably connected to both the seat and the frame. One end of the drive mechanism is rotatably connected to either the seat or the frame, while the other end is drively connected to the linkage mechanism to drive its movement relative to the frame. This causes the seat to move closer to or further away from the frame, achieving the purpose of folding or unfolding the wheelchair. Since the drive mechanism is an automatic drive mechanism, meaning it can provide its own driving force, this application achieves automatic folding or unfolding of the wheelchair through the drive mechanism. Furthermore, this method of folding the wheelchair is relatively simple to operate, thus improving the user experience. Therefore, the folding device disclosed in this application solves the problem of complex operation in related technologies for folding wheelchairs. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the unfolded state of the folding device disclosed in the embodiments of this application; Figures 2 to 4 These are schematic diagrams of the unfolded state of the folding device disclosed in the embodiments of this application from different perspectives. Figure 5 This is a schematic diagram of the folding device disclosed in the embodiments of this application in a folded state; Figure 6 This is a schematic diagram of the folding device disclosed in the embodiments of this application, folded to a certain angle.

[0010] Explanation of reference numerals in the attached figures: 100 - Seat, 110 - First mounting seat, 120 - Second mounting seat; 200 - Rack, 210 - Third mounting bracket; 300 - Linkage mechanism, 310 - First link, 320 - Second link; 400 - Drive mechanism; 500 - Rotary shaft assembly, 510 - Rotary shaft, 520 - Shaft sleeve. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0012] The folding device disclosed in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0013] Please refer to Figures 1 to 6This application discloses a folding device, which includes a linkage mechanism 300 and a drive mechanism 400.

[0014] This application discloses a folding device for installation between a wheelchair seat 100 and a frame 200, facilitating the folding or unfolding of the wheelchair. Specifically, a drive mechanism 400 has a driving function, and a linkage mechanism 300 can transmit power. One end of the linkage mechanism 300 is rotatably connected to the seat 100, and the other end is rotatably connected to the frame 200. The drive mechanism 400 is an automatic drive mechanism, meaning it can provide driving force itself. One end of the drive mechanism 400 is rotatably connected to either the seat 100 or the frame 200, and the other end is drively connected to the linkage mechanism 300 to drive the linkage mechanism 300 to move relative to the frame 200. During the movement of the linkage mechanism 300 relative to the frame 200, the linkage mechanism 300 can move the seat 100 closer to or further away from the frame 200, thereby achieving the purpose of folding or unfolding the wheelchair.

[0015] Optionally, the drive mechanism 400 can be a telescopic mechanism, such as a cylinder, hydraulic cylinder, or electric push rod. The folding device may also include a controller for controlling the operation of the drive mechanism 400. This application controls the operation of the drive mechanism 400 by controlling the working state of the controller. For example, this application can provide a button on the armrest of the seat 100, which is electrically connected to the controller. When the user presses the button, the controller starts working, thereby controlling the drive mechanism 400 to start working. When the user presses the button again, the controller stops working, thereby controlling the drive mechanism 400 to stop working and put the drive mechanism 400 in a locked state. At this time, the drive mechanism 400 stops driving the linkage mechanism 300 to move relative to the frame 200, thereby stopping the folding or unfolding of the wheelchair and keeping the wheelchair in its current state. Therefore, this application can start the drive mechanism 400 with one button, thereby achieving the purpose of automatically folding or unfolding the wheelchair, and this operation method is relatively simple and quick.

[0016] In this embodiment, the drive mechanism 400 may include a housing and a drive shaft. The drive shaft is telescopically disposed in the housing. When the drive end of the drive shaft extends to the position furthest from the housing, the drive mechanism 400 may be in a locked state, so that the folding device is in a balanced state and the seat 100 is furthest from the frame 200, that is, the seat 100 is in the highest position, in other words, the wheelchair is in an unfolded state. When the drive end of the drive shaft retracts to the position closest to the housing, the drive mechanism 400 may be in a locked state, so that the folding device is in a balanced state and the seat 100 is closest to the frame 200, that is, the seat 100 is in the lowest position, in other words, the wheelchair is in a folded state.

[0017] In this embodiment, the height of the seat 100 can be adjusted by adjusting the distance between the drive end of the drive shaft and the housing, that is, by adjusting the overall length of the drive mechanism 400, so as to meet the different usage needs of the user.

[0018] In this application, the linkage mechanism 300 is rotatably connected to both the seat 100 and the frame 200. One end of the drive mechanism 400 is rotatably connected to either the seat 100 or the frame 200, while the other end is drively connected to the linkage mechanism 300 to drive the linkage mechanism 300 to move relative to the frame 200, thereby causing the seat 100 to move closer to or further away from the frame 200, thus achieving the purpose of folding or unfolding the wheelchair. Since the drive mechanism 400 is an automatic drive mechanism, meaning it can provide its own driving force, this application can achieve the purpose of automatically folding or unfolding the wheelchair through the drive mechanism 400. Furthermore, this method of folding the wheelchair is relatively simple to operate, thereby improving the user experience. Therefore, the folding device disclosed in this application can solve the problem of the complexity of operation in related technologies for folding wheelchairs.

[0019] Alternatively, please refer to Figures 1 to 6 The linkage mechanism 300 may include a first link 310 and a second link 320 spaced apart. One end of the first link 310 and one end of the second link 320 are rotatably connected to the seat 100, and the other end of the first link 310 and the other end of the second link 320 are rotatably connected to the frame 200, so that the seat 100, the frame 200 and the linkage mechanism 300 form a quadrilateral structure.

[0020] In this embodiment, the drive mechanism 400 can be connected to one of the first link 310 and the second link 320. By driving one of the first link 310 and the second link 320 to rotate relative to the frame 200, the angles of the interior angles of the quadrilateral structure formed by the seat 100, the frame 200, and the linkage mechanism 300 change. During the rotation of the linkage mechanism 300, since one end of the first link 310 and one end of the second link 320 are always rotatably connected to the seat 100, the angle between the seat 100 and the ground or the frame 200 remains constant. This arrangement ensures the stability of the seat 100's movement, making it less likely for the user sitting on the seat 100 to fall off during the folding or unfolding of the wheelchair. Of course, in other embodiments, the linkage mechanism 300 may include only the first link 310 or the second link 320.

[0021] When the wheelchair switches from an unfolded state to a folded state, the drive mechanism 400 starts working, thereby changing the angle between the first link 310 and the second link 320 connected to the drive mechanism 400 and the seat 100 or the frame 200, thus changing the angle of each interior angle of the aforementioned quadrilateral structure. Under the gravity of the seat 100, the wheelchair begins to switch from an unfolded state to a folded state. Conversely, when the wheelchair switches from a folded state to an unfolded state, the drive mechanism 400 starts working, thereby changing the angle between the first link 310 and the second link 320 connected to the drive mechanism 400 and the seat 100 or the frame 200, thus changing the angle of each interior angle of the aforementioned quadrilateral structure. At the same time, the driving force output by the drive mechanism 400 is relatively large, which can overcome the gravity of the seat 100, thereby causing the wheelchair to switch from a folded state to an unfolded state.

[0022] Optionally, the lengths of the first link 310 and the second link 320 can be equal, and the first link 310 and the second link 320 can be parallel, so that the seat 100, the frame 200 and the linkage mechanism 300 can form a parallelogram structure. That is, the distance between one end of the first link 310 and one end of the second link 320 is equal to the distance between the other ends of the first link 310 and the second link 320. In other words, the length of the line connecting one end of the first link 310 and one end of the second link 320 is equal to the length of the line connecting the other ends of the first link 310 and the second link 320, and the line connecting one end of the first link 310 and one end of the second link 320 is parallel to the line connecting the other ends of the first link 310 and the second link 320.

[0023] In this embodiment, since the seat 100, frame 200, and linkage mechanism 300 form a parallelogram structure, the angular displacement, angular velocity, and angular acceleration of the first linkage 310 and the second linkage 320 remain equal during the folding or unfolding of the wheelchair. This characteristic significantly improves the motion synchronization and stability of the first linkage 310 and the second linkage 320, and also enhances the transmission efficiency of the linkage mechanism 300, thereby improving the motion smoothness and efficiency of the seat 100. Simultaneously, it allows for a relatively large degree of folding or unfolding of the wheelchair to meet different usage needs. Of course, in other embodiments, the lengths of the first linkage 310 and the second linkage 320 may not be equal, and the first linkage 310 and the second linkage 320 may not be parallel.

[0024] Optionally, one end of the drive mechanism 400 can be rotatably connected to the frame 200, and the other end of the drive mechanism 400 can be driveably connected to the first link 310 or the second link 320.

[0025] In another embodiment, please refer to Figures 1 to 6 One end of the drive mechanism 400 is rotatably connected to the seat 100, and the other end of the drive mechanism 400 is driveably connected to the first link 310 or the second link 320. That is, the drive mechanism 400 is located near the top of the wheelchair so that other components, such as mounting shelves, can be installed near the frame 200, i.e., the bottom of the wheelchair, to meet the different usage needs of the user.

[0026] Furthermore, the drive mechanism 400 can be a stepless telescopic mechanism, meaning that the drive mechanism 400 can stop at any position. In other words, the overall length of the drive mechanism 400 can be changed arbitrarily. During the folding or unfolding of the wheelchair, the seat 100 can be stopped at any height through the linkage mechanism 300. That is, the height of the seat 100 can be adjusted in various ways to meet different usage needs.

[0027] Optionally, in the height direction of the folding device, the height of one end of the first link 310 can be equal to the height of one end of the second link 320, and the height of the other end of the first link 310 can also be equal to the height of the other end of the second link 320. It should be noted that the height direction of this folding device is usually vertical.

[0028] In another embodiment, in the height direction of the folding device, the height of one end of the first link 310 can be less than the height of one end of the second link 320, and the height of the other end of the first link 310 can also be less than the height of the other end of the second link 320, so that the space occupied by the first link 310 and the second link 320 in the direction perpendicular to the height direction of the folding device, that is, in the horizontal direction, is relatively small, thereby making the space occupied by the wheelchair in the horizontal direction relatively small.

[0029] Optionally, the number of linkage mechanisms 300 can be one.

[0030] In another embodiment, please refer to Figure 2 and Figure 3 The linkage mechanism 300 can be at least two, with each linkage mechanism 300 spaced apart and used to rotatably connect with the seat 100 and the frame 200. Each linkage mechanism 300 can stably support the seat 100, thus ensuring the reliability and stability of the overall wheelchair structure. Furthermore, during the folding or unfolding of the wheelchair, it can improve the wheelchair's movement stability, thus ensuring the reliable operation of the entire wheelchair.

[0031] Optionally, each linkage mechanism 300 can be connected to different drive mechanisms 400, that is, the number of drive mechanisms 400 can be at least two, and each linkage mechanism 300 and each drive mechanism 400 can correspond one-to-one and be connected in transmission.

[0032] In another embodiment, each linkage mechanism 300 can be connected to the same drive mechanism 400, that is, the same drive mechanism 400 can drive each linkage mechanism 300 to move simultaneously, so that the movement synchronization of each linkage mechanism 300 is better, thereby further improving the stability of the folding or unfolding wheelchair.

[0033] Optionally, the folding device may further include a pivot assembly 500, wherein at least one of the following can be rotatably connected: one end of the linkage mechanism 300 to the seat 100, the other end of the linkage mechanism 300 to the frame 200, one end of the drive mechanism 400 to the seat 100 or the frame 200, and the other end of the drive mechanism 400 to the linkage mechanism 300, and the pivot assembly 500 is detachably disposed on the aforementioned at least one.

[0034] In this embodiment, the pivot assembly 500 allows at least one of the following connections to be rotatably connected: one end of the linkage mechanism 300 to the seat 100; the other end of the linkage mechanism 300 to the frame 200; one end of the drive mechanism 400 to the seat 100 or the frame 200; and the other end of the drive mechanism 400 to the linkage mechanism 300. Since the pivot assembly 500 is detachably mounted on at least one of these connections, it facilitates the removal of at least one of the linkage mechanism 300, drive mechanism 400, seat 100, and frame 200 for maintenance or replacement. Of course, in other embodiments, the pivot assembly 500 may be non-detachably mounted on at least one of these connections.

[0035] Alternatively, please refer to Figure 3 The pivot assembly 500 may include a pivot 510 and a bushing 520 that are rotatably engaged. At least one of the following connections may be rotatably connected: one end of the linkage mechanism 300 to the seat 100; the other end of the linkage mechanism 300 to the frame 200; one end of the drive mechanism 400 to the seat 100 or the frame 200; and the other end of the drive mechanism 400 to the linkage mechanism 300. The bushing 520 may be fitted over the pivot 510 to prevent friction and wear between the pivot 510 and at least one of the linkage mechanism 300, drive mechanism 400, seat 100, and frame 200, thereby avoiding affecting the structural strength of the overall structure. Of course, in other embodiments, the pivot assembly 500 may not include the bushing 520.

[0036] Optionally, there can be multiple pivot assemblies 500, so that one end of the linkage mechanism 300 can be rotatably connected to the seat 100, the other end of the linkage mechanism 300 can be connected to the frame 200, one end of the drive mechanism 400 can be connected to the seat 100 or the frame 200, and the other end of the drive mechanism 400 can be connected to the linkage mechanism 300 via different pivots 510 and bushings 520.

[0037] Specifically, one end of the linkage mechanism 300 may be provided with a first through hole, and the bushing 520 between one end of the linkage mechanism 300 and the seat 100 may be fitted into the first through hole. One end of the rotating shaft 510 between one end of the linkage mechanism 300 and the seat 100 may pass through the bushing 520 and be rotatably connected to the seat 100. The other end of the linkage mechanism 300 may be provided with a second through hole, and the bushing 520 between the other end of the linkage mechanism 300 and the frame 200 may be fitted into the second through hole. One end of the rotating shaft 510 between the other end of the linkage mechanism 300 and the frame 200 may pass through the bushing 520 and be rotatably connected to the frame 200.

[0038] One end of the drive mechanism 400 may be provided with a third through hole, and a bushing 520 between one end of the drive mechanism 400 and the seat 100 or the frame 200 may be fitted into the third through hole. One end of the rotating shaft 510 between one end of the drive mechanism 400 and the seat 100 or the frame 200 may pass through the bushing 520 and be rotatably connected to the seat 100 or the frame 200. The other end of the drive mechanism 400 may be provided with a fourth through hole, and a bushing 520 between the other end of the drive mechanism 400 and the linkage mechanism 300 may be fitted into the fourth through hole. One end of the rotating shaft 510 between the other end of the drive mechanism 400 and the linkage mechanism 300 may pass through the bushing 520 and be rotatably connected to the linkage mechanism 300. Of course, in other embodiments, the areas of the seat 100 and the frame 200 that are rotatably connected to different rotating shafts 510 may also be provided with bushings 520. This application embodiment does not impose specific limitations on this.

[0039] Optionally, the pivot 510 can be a bolt, and the pivot assembly 500 can also include a nut. Taking the pivot 510 located between one end of the linkage mechanism 300 and the seat 100 as an example, one end of the pivot 510 can pass sequentially through one end of the linkage mechanism 300 and the seat 100, and cooperate with the nut to stably connect one end of the linkage mechanism 300 and the seat 100, while ensuring that one end of the linkage mechanism 300 is rotatably engaged with the seat 100. It should be noted that other rotatably connected components can also be stably connected through other pivots 510 and other nuts, which will not be elaborated here.

[0040] Optionally, as can be seen from the foregoing, each linkage mechanism 300 can be connected to the same drive mechanism 400 for transmission. Since the linkage mechanisms 300 are spaced apart, the length of the aforementioned rotating shaft 510 between each linkage mechanism 300 and the same drive mechanism 400 is relatively long, so as to connect each linkage mechanism 300 with the same drive mechanism 400.

[0041] Alternatively, to improve the overall connection stability and structural strength, both the rotating shaft 510 and the linkage mechanism 300 can be made of metal.

[0042] Optionally, this application also discloses a wheelchair, including a seat 100, a frame 200, and the folding device described above, which can be installed between the seat 100 and the frame 200.

[0043] Alternatively, please refer to Figures 1 to 6 A first mounting base 110 may protrude from the seat 100 or the frame 200. One end of the drive mechanism 400 may be rotatably connected to the first mounting base 110. The first mounting base 110 facilitates the installation of the drive mechanism 400. Furthermore, providing the first mounting base 110 on the seat 100 or the frame 200 can, to a certain extent, increase the contact area between the seat 100 or the frame 200 and the drive mechanism 400, thereby improving the connection stability between the seat 100 or the frame 200 and the drive mechanism 400, i.e., improving the installation stability of the drive mechanism 400. Of course, in other embodiments, the first mounting base 110 may not protrude from the seat 100 or the frame 200.

[0044] Optionally, a second mounting base 120 may protrude from the seat 100, and one end of the linkage mechanism 300 may be rotatably connected to the second mounting base 120. The second mounting base 120 facilitates the installation of the linkage mechanism 300. Furthermore, providing the second mounting base 120 on the seat 100 can, to a certain extent, increase the contact area between the seat 100 and the linkage mechanism 300, thereby improving the connection stability between the seat 100 and the linkage mechanism 300, i.e., improving the installation stability of the linkage mechanism 300. Of course, in other embodiments, the second mounting base 120 may not protrude from the seat 100.

[0045] Optionally, a third mounting base 210 protrudes from the frame 200, and the other end of the linkage mechanism 300 is rotatably connected to the third mounting base 210. The third mounting base 210 facilitates the installation of the linkage mechanism 300. Simultaneously, providing the third mounting base 210 on the frame 200 can, to a certain extent, increase the contact area between the frame 200 and the linkage mechanism 300, thereby improving the connection stability between the frame 200 and the linkage mechanism 300, i.e., improving the installation stability of the linkage mechanism 300. Of course, in other embodiments, the third mounting base 210 may not protrude from the frame 200.

[0046] Optionally, as can be seen from the foregoing, the linkage mechanism 300 may include a first link 310 and a second link 320. Please refer to [reference needed]. Figures 2 to 4 and Figure 6 One end of the first link 310 and one end of the second link 320 can be rotatably connected to the second mounting base 120, and the other end of the first link 310 and the other end of the second link 320 can be rotatably connected to the third mounting base 210, thereby simplifying the overall structure and disassembly / assembly operations.

[0047] The above embodiments of this application focus on describing the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be described in detail here.

[0048] 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 folding device for mounting between a wheelchair seat (100) and a frame (200), characterized in that, The folding device includes a linkage mechanism (300) and a drive mechanism (400). One end of the linkage mechanism (300) is rotatably connected to the seat (100), and the other end of the linkage mechanism (300) is rotatably connected to the frame (200). The drive mechanism (400) is an automatic drive mechanism, and one end of the drive mechanism (400) is rotatably connected to either the seat (100) or the frame (200). The other end of the drive mechanism (400) is drively connected to the linkage mechanism (300) to drive the linkage mechanism (300) to move relative to the frame (200), so that the seat (100) moves closer to or further away from the frame (200).

2. The folding device according to claim 1, characterized in that, The linkage mechanism (300) includes a first link (310) and a second link (320) spaced apart. One end of the first link (310) and one end of the second link (320) are rotatably connected to the seat (100). The other end of the first link (310) and the other end of the second link (320) are rotatably connected to the frame (200) so that the seat (100), the frame (200) and the linkage mechanism (300) form a quadrilateral structure.

3. The folding device according to claim 2, characterized in that, The length of the first link (310) is equal to the length of the second link (320), and the first link (310) and the second link (320) are parallel, so that the seat (100), the frame (200) and the linkage mechanism (300) form a parallelogram structure.

4. The folding device according to claim 2, characterized in that, One end of the drive mechanism (400) is rotatably connected to the seat (100), and the other end of the drive mechanism (400) is driveably connected to the first link (310) or the second link (320), and the drive mechanism (400) is a continuously telescopic mechanism; and / or, In the height direction of the folding device, the height of one end of the first link (310) is less than the height of one end of the second link (320), and the height of the other end of the first link (310) is less than the height of the other end of the second link (320).

5. The folding device according to claim 1, characterized in that, The number of linkage mechanisms (300) is at least two, and each linkage mechanism (300) is spaced apart and is used to rotatably connect with the seat (100) and the frame (200).

6. The folding device according to claim 5, characterized in that, Each of the linkage mechanisms (300) is connected to the same drive mechanism (400) in a transmission manner.

7. The folding device according to claim 1, characterized in that, The folding device further includes a pivot assembly (500), at least one of the following: one end of the linkage mechanism (300) is rotatably connected to the seat (100); the other end of the linkage mechanism (300) is connected to the frame (200); one end of the drive mechanism (400) is connected to the seat (100) or the frame (200); and the other end of the drive mechanism (400) is connected to the linkage mechanism (300). The pivot assembly (500) is detachably disposed on the at least one of the above-mentioned components.

8. The folding device according to claim 7, characterized in that, The rotating shaft assembly (500) includes a rotating shaft (510) and a bushing (520) that are rotatably engaged. At least one of the following is rotatably connected via the rotating shaft (510) and the bushing (520): one end of the linkage mechanism (300) to the seat (100), the other end of the linkage mechanism (300) to the frame (200), one end of the drive mechanism (400) to the seat (100) or the frame (200), and the other end of the drive mechanism (400) to the linkage mechanism (300). The bushing (520) is sleeved outside the rotating shaft (510).

9. A wheelchair, characterized in that, It includes a seat (100), a frame (200), and a folding device according to any one of claims 1-8, the folding device being installed between the seat (100) and the frame (200).

10. The wheelchair according to claim 9, characterized in that, A first mounting base (110) protrudes from the seat (100) or the frame (200), and one end of the drive mechanism (400) is rotatably connected to the first mounting base (110); and / or, The seat (100) has a protruding second mounting base (120), and one end of the linkage mechanism (300) is rotatably connected to the second mounting base (120); and / or, The frame (200) has a protruding third mounting base (210), and the other end of the linkage mechanism (300) is rotatably connected to the third mounting base (210).

Images