A gripper capable of quickly adjusting the position of the suction cup
By designing a gripper that allows for quick adjustment of the suction cup position, the problem of production line stoppage caused by gripper replacement was solved. This enabled flexible adaptation and efficient gripping of heat insulation pads of different sizes, thereby improving production efficiency.
Patent Information
- Application Number
- CN202522100546.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-29
- Publication Date
- 2026-08-25
- Estimated Expiration
- 2035-09-29
AI Technical Summary
The existing battery production line needs to be paused to change the gripper when replacing heat insulation pads of different sizes, which affects production efficiency.
Design a gripper that can quickly adjust the position of the suction cup. Through the movable second and third suction components, combined with the locking component, the position of the suction cup can be flexibly adjusted to meet the gripping needs of various sizes of heat insulation pads.
It improves the production efficiency of the production line, avoids line stoppages caused by changing grippers, and enables flexible adaptation and efficient gripping of heat insulation pads of different sizes.
Smart Images

Figure CN224674931U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of battery accessory assembly equipment, specifically to a gripper that can quickly adjust the position of the suction cup. Background Technology
[0002] During battery module production, heat insulation pads need to be applied to the side surfaces of the batteries to adhere to and isolate adjacent batteries. These pads provide thermal insulation between adjacent batteries. The size of the heat insulation pads is basically the same as the battery side surface. Different battery sizes are specifically equipped with heat insulation pads of corresponding sizes, and the heat insulation pad grippers are designed to be roughly the same size as the pads. If a different sized heat insulation pad is encountered, the production line needs to be paused to replace the appropriate gripper, which significantly impacts production efficiency.
[0003] Therefore, it is necessary to provide a gripper that can quickly adjust the position of the suction cup to overcome the above-mentioned defects. Utility Model Content
[0004] The purpose of this invention is to provide a gripper that can quickly adjust the position of the suction cup. It can quickly and flexibly adjust the positions of the second and third adsorption components according to the size of the heat insulation pad being adsorbed, thus meeting the needs of the material-picking suction cup gripper to pick up heat insulation pads of various sizes. It has high versatility and eliminates the need to stop the production line to replace the corresponding gripper for each size of heat insulation pad, greatly improving the production efficiency of the production line.
[0005] To achieve the above objectives, this utility model provides a gripper capable of quickly adjusting the position of the suction cup, comprising: a substrate, a first suction component, a second suction component, a third suction component, a first locking component, and a second locking component. The first adsorption component is fixedly mounted on the substrate, the second adsorption component is movably mounted on the substrate, and the third adsorption component is movably mounted on the substrate and disposed opposite to the first adsorption component. The third adsorption component is movably mounted on the substrate and located on one side of the first and second adsorption components. The first locking component is mounted on the substrate and connected to the second adsorption component. The second locking component is mounted on the substrate and connected to the third adsorption component. The first locking component is used to lock the second adsorption component onto the substrate, and the second locking component is used to lock the third adsorption component onto the substrate.
[0006] Preferably, the first adsorption component includes a first base plate, a first mounting base, and a first suction cup. The first base plate is fixedly mounted on the substrate, the first mounting base is fixedly mounted on the first base plate, and the first suction cup is detachably mounted on the first mounting base. The first mounting base is provided with an air pipe connector connected to the first suction cup.
[0007] Preferably, the substrate has longitudinal strip holes and transverse strip holes, the second adsorption component is movably installed at the longitudinal strip holes and is disposed opposite to the first adsorption component, and the third adsorption component is movably installed at the transverse strip holes.
[0008] Preferably, the second adsorption assembly includes a second base plate, a second mounting base, and a second suction cup; the second base plate is movably mounted at the longitudinal strip hole, the second mounting base is mounted on the second base plate, the second suction cup is mounted on the second mounting base, and the second mounting base is provided with an air pipe connector connected to the second suction cup.
[0009] Preferably, a first guide rail is provided on the substrate near the longitudinal strip hole, and the first guide rail is parallel to the longitudinal strip hole. A first slider is provided on the bottom of the second base plate, and the first slider is slidably connected to the first guide rail.
[0010] Preferably, the first locking assembly includes a first rack, a second rack, a first connecting plate, a first mounting block, a first pull rod, and a first elastic element. The first rack is mounted on the substrate and parallel to the longitudinal strip hole. The second rack is located directly above the first rack. The first connecting plate is located above the second rack and connected to the second base plate. The first mounting block is mounted on the first connecting plate. The first pull rod is movably inserted and mounted on the first mounting block and the first connecting plate, and the first pull rod is connected to the top of the second rack. The first elastic element is sleeved on the first pull rod and movably mounted inside the first mounting block and the first connecting plate. When the first elastic element is in a stretched state, it can make the second rack mesh with the first rack.
[0011] Preferably, the third adsorption component includes a third base plate, a third mounting base, and a third suction cup; the third base plate is movably installed at the transverse strip hole, the third mounting base is installed on the third base plate, the third suction cup is installed on the third mounting base, and the third mounting base is provided with an air pipe connector connected to the third suction cup.
[0012] Preferably, a second guide rail is provided on the substrate near the transverse strip hole, and the second guide rail is parallel to the transverse strip hole. A second slider is provided on the bottom of the third base plate, and the second slider is slidably connected to the second guide rail.
[0013] Preferably, the second locking assembly includes a third rack, a fourth rack, a second connecting plate, a second mounting block, a second pull rod, and a second elastic element. The third rack is mounted on the base plate and parallel to the transverse strip hole. The fourth rack is located directly above the third rack. The second connecting plate is located above the fourth rack and connected to the third base plate. The second mounting block is mounted on the second connecting plate. The second pull rod is movably inserted and mounted on the second mounting block and the second connecting plate, and the second pull rod is connected to the top of the fourth rack. The second elastic member is sleeved on the second pull rod and movably mounted inside the second mounting block and the second connecting plate. When the second elastic member is in a stretched state, it can make the fourth rack mesh with the third rack.
[0014] Compared with existing technologies, the advantages are: the positions of the second and third adsorption components can be quickly and flexibly adjusted according to the size of the heat insulation pad being adsorbed, which can meet the needs of the material-grabbing suction cup gripper to grasp heat insulation pads of various sizes. It has high versatility and no longer requires stopping the production line to replace the corresponding gripper for each size of heat insulation pad, which greatly improves the production efficiency of the production line. Attached Figure Description
[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 This is a top view of the gripper that allows for quick adjustment of the suction cup position, as provided by this utility model.
[0017] Figure 2 for Figure 1 The image shown is a 3D view of a gripper that allows for quick adjustment of the suction cup position.
[0018] Figure 3 for Figure 1 The diagram shows a partial structure of the gripper that allows for quick adjustment of the suction cup position.
[0019] Figure 4 for Figure 1 The diagram shows a partial structure of the gripper that allows for quick adjustment of the suction cup position.
[0020] Figure 5 for Figure 1 The image shown is a 3D view of a gripper that allows for quick adjustment of the suction cup position.
[0021] Reference numerals: 1. Substrate; 11. Longitudinal strip hole; 12. Transverse strip hole; 13. First guide rail; 14. Second guide rail; 2. First adsorption assembly; 21. First base plate; 22. First mounting base; 23. First suction cup; 3. Second adsorption assembly; 31. Second base plate; 32. Second mounting base; 33. Second suction cup; 34. First slider; 4. Third adsorption assembly; 41. Third base plate; 42. Third mounting base; 43. Third suction cup; 44. Second slider; 5. First locking assembly; 51. First rack; 52. Second rack; 53. First connecting plate; 54. First mounting block; 55. First pull rod; 56. First elastic element; 6. Second locking assembly; 61. Third rack; 62. Fourth rack; 63. Second connecting plate; 64. Second mounting block; 65. Second pull rod; 66. Second elastic element; 7. Air pipe connector. Detailed Implementation
[0022] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described in this specification are merely for explaining the present utility model and are not intended to limit the present utility model.
[0023] It should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0024] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," "fixing," and "setting" 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 or an electrical 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. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.
[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Additionally, "multiple" or "several" means two or more, unless otherwise explicitly specified.
[0026] Please see Figures 1 to 5 This utility model provides a gripper capable of quickly adjusting the position of the suction cup, comprising: a substrate 1, a first suction component 2, a second suction component 3, a third suction component 4, a first locking component 5, and a second locking component 6. The first adsorption component 2 is fixedly mounted on the substrate 1, the second adsorption component 3 is movably mounted on the substrate 1, and the third adsorption component 4 is movably mounted on the substrate 1 and is disposed opposite to the first adsorption component 2. The third adsorption component 4 is movably mounted on the substrate 1 and is located on one side (right side) of the first adsorption component 2 and the second adsorption component 3. The first locking component 5 is mounted on the substrate 1 and connected to the second adsorption component 3. The second locking component 6 is mounted on the substrate 1 and connected to the third adsorption component 4. The first locking component 5 is used to lock the second adsorption component 3 onto the substrate 1, and the second locking component 6 is used to lock the third adsorption component 4 onto the substrate 1.
[0027] Since the second adsorption component 3 and the third adsorption component 4 are movably mounted on the substrate 1, their positions can be adjusted according to the size of the heat insulation pad. Then, the first locking component 5 and the second locking component 6 respectively lock the second adsorption component 3 and the third adsorption component 4 onto the substrate 1, allowing the first adsorption component 2, the second adsorption component 3, and the third adsorption component 4 on the material-picking suction cup gripper to jointly adsorb the heat insulation pad. This allows for quick and flexible adjustment of the positions of the second adsorption component 3 and the third adsorption component 4 according to the size of the heat insulation pad being adsorbed, meeting the needs of the material-picking suction cup gripper to grasp heat insulation pads of various sizes. This high versatility eliminates the need to stop the production line to replace the corresponding gripper for each size of heat insulation pad, greatly improving the production line's efficiency.
[0028] In one specific embodiment, the substrate 1 has a longitudinal strip hole 11 and a transverse strip hole 12. The second adsorption component 3 is movably installed at the longitudinal strip hole 11 and is disposed opposite to the first adsorption component 2. The third adsorption component 4 is movably installed at the transverse strip hole 12.
[0029] Thus, by pre-opening longitudinal strip holes 11 and transverse strip holes 12 on the substrate 1, the second adsorption component 3 can be easily installed at the longitudinal strip holes 11 and its installation position can be flexibly adjusted along the longitudinal strip holes 11; the third adsorption component 4 can be easily installed at the transverse strip holes 12 and its installation position can be flexibly adjusted along the transverse strip holes 12.
[0030] In one specific embodiment, the first adsorption component 2 includes a first base plate 21, a first mounting base 22, and a first suction cup 23. The first base plate 21 is fixedly mounted on the substrate 1, the first mounting base 22 is fixedly mounted on the first base plate 21, and the first suction cup 23 is detachably mounted on the first mounting base 22. An air pipe connector 7 is provided on the first mounting base 22 to connect to the first suction cup 23. It should be noted that in this embodiment, there are two first suction cups 23. Negative air pressure is provided to the first suction cup 23 through an external air pipe connected to the air pipe connector 7, which enables the first suction cup 23 to have good adsorption force.
[0031] In this way, the position of the first suction component 2 can be fixed and kept unchanged; and since the first suction cup 23 is detachable, it is convenient to remove and replace the first suction cup 23 when it is damaged.
[0032] In one specific embodiment, the second adsorption component 3 includes a second base plate 31, a second mounting base 32, and a second suction cup 33. The second base plate 31 is movably mounted at the longitudinal strip hole 11, the second mounting base 32 is mounted on the second base plate 31, and the second suction cup 33 is mounted on the second mounting base 32. An air pipe connector 7 is provided on the second mounting base 32 to connect to the second suction cup 33. It should be noted that in this embodiment, there are two second suction cups 33. Negative air pressure is provided to the second suction cups 33 through an external air pipe connected to the air pipe connector 7, which enables the second suction cups 33 to have good adsorption force.
[0033] In this way, the position of the second suction component 3 on the substrate 1 can be adjusted, and since the second suction cup 33 is detachable, it is convenient to remove and replace the second suction cup 33 when it is damaged.
[0034] In one specific embodiment, a first guide rail 13 is provided on the substrate 1 near the longitudinal strip hole 11, and the first guide rail 13 is parallel to the longitudinal strip hole 11. A first slider 34 is provided on the bottom of the second base plate 31, and the first slider 34 is slidably connected to the first guide rail 13. In this way, the second adsorption component 3 can be stably installed, and the position of the second adsorption component 3 can be flexibly adjusted on the first guide rail 13.
[0035] In one specific embodiment, the third adsorption component 4 includes a third base plate 41, a third mounting base 42, and a third suction cup 43. The third base plate 41 is movably mounted at the transverse slot 12, the third mounting base 42 is mounted on the third base plate 41, and the third suction cup 43 is mounted on the third mounting base 42. An air pipe connector 7 is provided on the third mounting base 42 to connect to the third suction cup 43. It should be noted that in this embodiment, there are two third suction cups 43. Negative air pressure is provided to the third suction cups 43 through the air pipe connector 7 connected to an external air pipe, which enables the third suction cups 43 to have good adsorption force.
[0036] In this way, the position of the third adsorption component 4 on the substrate 1 can be adjusted, and since the third suction cup 43 is detachable, it is convenient to remove and replace the third suction cup 43 when it is damaged.
[0037] In one specific embodiment, a second guide rail 14 is provided on the substrate 1 near the transverse strip hole 12, and the second guide rail 14 is parallel to the transverse strip hole 12. A second slider 44 is provided on the bottom of the third base plate 41, and the second slider 44 is slidably connected to the second guide rail 14. In this way, the third adsorption component 4 can be stably installed, and the position of the third adsorption component 4 can be flexibly adjusted on the second guide rail 14.
[0038] In one specific embodiment, the first locking assembly 5 includes a first rack 51, a second rack 52, a first connecting plate 53, a first mounting block 54, a first pull rod 55, and a first elastic element 56. The first rack 51 is mounted on the base plate 1 and parallel to the longitudinal strip hole 11. The second rack 52 is located directly above the first rack 51. The first connecting plate 53 is located above the second rack 52 and connected to the second base plate 31. The first mounting block 54 is mounted on the first connecting plate 53. The first pull rod 55 is movably inserted and mounted on the first mounting block 54 and the first connecting plate 53, and the first pull rod 55 is connected to the top of the second rack 52. The first elastic member 56 is sleeved on the first pull rod 55 and movably mounted inside the first mounting block 54 and the first connecting plate 53. When the first elastic member 56 is in a stretched state, it can make the second rack 52 mesh with the first rack 51.
[0039] Normally, without external force, the first elastic element 56 is in a stretched state, causing the second rack 52 to engage with the first rack 51, thus locking the second adsorption assembly 3. When it is necessary to adjust the position of the second adsorption assembly 3 on the first guide rail 13, the first pull rod 55 needs to be pulled up first. At this time, the first elastic element 56 is compressed inside the first connecting plate 53 and the first mounting block 54, and the second rack 52 and the first rack 51 are temporarily separated. Then, by pushing the first connecting plate 53 or the second base plate 31, the position of the second adsorption assembly 3 on the first guide rail 13 can be adjusted as needed.
[0040] After adjusting the position of the second adsorption component 3, the first pull rod 55 is released. The first elastic element 56 returns to its stretched state under its own elasticity. Under the action of the first elastic element 56, the first pull rod 55 drives the second rack 52 to mesh with the first rack 51 again, locking the second adsorption component 3.
[0041] In one specific embodiment, the second locking assembly 6 includes a third rack 61, a fourth rack 62, a second connecting plate 63, a second mounting block 64, a second pull rod 65, and a second elastic element 66. The third rack 61 is mounted on the base plate 1 and parallel to the transverse strip hole 12. The fourth rack 62 is located directly above the third rack 61. The second connecting plate 63 is located above the fourth rack 62 and connected to the third base plate 41. The second mounting block 64 is mounted on the second connecting plate 63. The second pull rod 65 is movably inserted and mounted on the second mounting block 64 and the second connecting plate 63, and the second pull rod 65 is connected to the top of the fourth rack 62. The second elastic member 66 is sleeved on the second pull rod 65 and movably mounted inside the second mounting block 64 and the second connecting plate 63. When the second elastic member 66 is in a stretched state, it can make the fourth rack 62 mesh with the third rack 61.
[0042] Normally, without external force, the second elastic element 66 is in a stretched state, engaging the fourth rack 62 with the third rack 61, thus locking the third adsorption assembly 4. When it is necessary to adjust the position of the third adsorption assembly 4 on the second guide rail 14, the second pull rod 65 needs to be pulled up first. At this time, the second elastic element 66 is compressed inside the second connecting plate 63 and the second mounting block 64, and the fourth rack 62 and the third rack 61 are temporarily separated. Then, by pushing the second connecting plate 63 or the third base plate 41, the position of the third adsorption assembly 4 on the second guide rail 14 can be adjusted as needed.
[0043] After adjusting the position of the third adsorption component 4, the second pull rod 65 is released. The second elastic element 66 returns to its stretched state under its own elasticity. Under the action of the second elastic element 66, the second pull rod 65 drives the fourth rack 62 to mesh with the third rack 61 again, locking the third adsorption component 4.
[0044] It should be noted that in this embodiment, both the first elastic element 56 and the second elastic element 66 are springs. There are three of each of the following: the first adsorption component 2, the second adsorption component 3, and the third adsorption component 4. Each first adsorption component 2 corresponds to one second adsorption component 3 and one third adsorption component 4. The three first adsorption components 2 are installed at the three red dotted boxes, the three second adsorption components 3 are installed at the three blue dotted boxes, and the three third adsorption components 4 are installed at the three black dotted boxes. The specific installation positions are as follows: Figure 1 As shown, it can simultaneously meet the needs of multiple heat insulation pads, improving material handling efficiency. The first connecting plate 53 is simultaneously connected to the second base plate 31 of the three second adsorption components 3, and the second connecting plate 63 is simultaneously connected to the third base plate 41 of the three third adsorption components 4, allowing for simultaneous adjustment of the positions of the three second adsorption components 3 and the three third adsorption components 4.
[0045] This invention is not limited to the description and embodiments described herein, and thus other advantages and modifications can be readily realized by those skilled in the art. Therefore, without departing from the spirit and scope of the general concept defined by the claims and their equivalents, this invention is not limited to the specific details, representative devices and examples shown and described herein.
Claims
1. A gripper capable of quickly adjusting the position of a suction cup, characterized in that, include: Substrate (1), first adsorption component (2), second adsorption component (3), third adsorption component (4), first locking component (5) and second locking component (6). The first adsorption component (2) is fixedly mounted on the substrate (1), the second adsorption component (3) is movably mounted on the substrate (1), and the third adsorption component (4) is movably mounted on the substrate (1) and disposed opposite to the first adsorption component (2). The third adsorption component (4) is movably mounted on the substrate (1) and located on one side of the first adsorption component (2) and the second adsorption component (3). The first locking component (5) is mounted on the substrate (1) and connected to the second adsorption component (3). The second locking component (6) is mounted on the substrate (1) and connected to the third adsorption component (4). The first locking component (5) is used to lock the second adsorption component (3) onto the substrate (1). The second locking component (6) is used to lock the third adsorption component (4) onto the substrate (1).
2. The gripper capable of quickly adjusting the position of the suction cup as described in claim 1, characterized in that, The first adsorption component (2) includes a first base plate (21), a first mounting base (22) and a first suction cup (23). The first base plate (21) is fixedly mounted on the base plate (1), the first mounting base (22) is fixedly mounted on the first base plate (21), and the first suction cup (23) is detachably mounted on the first mounting base (22). The first mounting base (22) is provided with an air pipe connector (7) connected to the first suction cup (23).
3. The gripper capable of quickly adjusting the position of the suction cup as described in claim 1, characterized in that, The substrate (1) has a longitudinal strip hole (11) and a transverse strip hole (12). The second adsorption component (3) is movably installed at the longitudinal strip hole (11) and is arranged opposite to the first adsorption component (2). The third adsorption component (4) is movably installed at the transverse strip hole (12).
4. The gripper capable of quickly adjusting the suction cup position as described in claim 3, characterized in that, The second adsorption component (3) includes a second base plate (31), a second mounting base (32), and a second suction cup (33); the second base plate (31) is movably installed at the longitudinal strip hole (11), the second mounting base (32) is installed on the second base plate (31), the second suction cup (33) is installed on the second mounting base (32), and the second mounting base (32) is provided with an air pipe connector (7) connected to the second suction cup (33).
5. The gripper capable of quickly adjusting the position of the suction cup as described in claim 4, characterized in that, The substrate (1) is provided with a first guide rail (13) near the longitudinal strip hole (11), and the first guide rail (13) is parallel to the longitudinal strip hole (11). The bottom of the second base plate (31) is provided with a first slider (34), and the first slider (34) is slidably connected to the first guide rail (13).
6. The gripper capable of quickly adjusting the position of the suction cup as described in claim 4, characterized in that, The first locking assembly (5) includes a first rack (51), a second rack (52), a first connecting plate (53), a first mounting block (54), a first pull rod (55), and a first elastic element (56). The first rack (51) is mounted on the substrate (1) and parallel to the longitudinal strip hole (11). The second rack (52) is located directly above the first rack (51). The first connecting plate (53) is located above the second rack (52) and connected to the second base plate (31). The first mounting block (54) is mounted on the first connecting plate (53). The first pull rod (55) is movably inserted and mounted on the first mounting block (54) and the first connecting plate (53), and the first pull rod (55) is connected to the top of the second rack (52). The first elastic member (56) is sleeved on the first pull rod (55) and movably mounted inside the first mounting block (54) and the first connecting plate (53). When the first elastic member (56) is in a stretched state, it can make the second rack (52) mesh with the first rack (51).
7. The gripper capable of quickly adjusting the position of the suction cup as described in claim 4, characterized in that, The third adsorption component (4) includes a third base plate (41), a third mounting base (42), and a third suction cup (43); the third base plate (41) is movably installed at the transverse strip hole (12), the third mounting base (42) is mounted on the third base plate (41), the third suction cup (43) is mounted on the third mounting base (42), and the third mounting base (42) is provided with an air pipe connector (7) connected to the third suction cup (43).
8. The gripper capable of quickly adjusting the position of the suction cup as described in claim 7, characterized in that, The substrate (1) is provided with a second guide rail (14) near the transverse strip hole (12), and the second guide rail (14) is parallel to the transverse strip hole (12). The bottom of the third base plate (41) is provided with a second slider (44), and the second slider (44) is slidably connected to the second guide rail (14).
9. The gripper capable of quickly adjusting the position of the suction cup as described in claim 8, characterized in that, The second locking assembly (6) includes a third rack (61), a fourth rack (62), a second connecting plate (63), a second mounting block (64), a second pull rod (65), and a second elastic element (66). The third rack (61) is mounted on the base plate (1) and parallel to the transverse strip hole (12). The fourth rack (62) is located directly above the third rack (61). The second connecting plate (63) is located above the fourth rack (62) and connected to the third base plate (41). The second mounting block (64) is mounted on the second connecting plate (63). The second pull rod (65) is movably inserted and mounted on the second mounting block (64) and the second connecting plate (63), and the second pull rod (65) is connected to the top of the fourth rack (62). The second elastic member (66) is sleeved on the second pull rod (65) and movably mounted inside the second mounting block (64) and the second connecting plate (63). When the second elastic member (66) is in a stretched state, it can make the fourth rack (62) mesh with the third rack (61).