A vertical curtain hook
By designing a rotating hole and disassembly port structure for vertical curtain hooks, the problem of difficult curtain hanging parts can be solved, enabling convenient installation and replacement, and reducing maintenance costs and time.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 胡智合
- Filing Date
- 2025-09-16
- Publication Date
- 2026-06-26
Smart Images

Figure CN224413510U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of vertical curtain technology, specifically to a vertical curtain hook. Background Technology
[0002] Vertical blinds are a type of blind named for their slats hanging vertically from an upper track.
[0003] In the prior art, such as the invention patent disclosed in patent application publication number CN118924096 A, a curtain bead and a dream curtain, the second bevel gear body of the curtain bead is provided with a bushing, the bushing forms a slot in the middle and is provided with a positioning hole. When the snap-fit part of the curtain hanger is inserted into the slot from bottom to top and stops at the bottom of the slot, the snap-fit part extends into the positioning hole, thereby fixing the curtain hanger to the bushing.
[0004] In practical use, curtain beads are usually made of plastic. The curtain hanger, as a key component directly bearing the weight of the vertical blind slats, is fixed by snaps that engage with positioning holes. Once secured, these snaps and positioning holes form an irreversible lock, making the curtain hanger difficult to remove after installation. Over long-term use, the continuous weight of the vertical blind slats puts constant stress on the engagement points of the snaps and positioning holes, leading to wear, deformation, or even breakage. Because of the irreversible lock, when a curtain hanger is damaged, it's often difficult to replace only the damaged hanger; the entire curtain bead system must be replaced. This not only increases maintenance costs for users but also prolongs maintenance time, hindering cost control. Utility Model Content
[0005] In order to overcome the shortcomings of the existing technology, this utility model provides a vertical curtain hook.
[0006] The technical solution adopted by this utility model to solve its technical problem is:
[0007] A vertical curtain hook includes a base and a curtain hanger. The base has a transmission cavity, and the transmission cavity has a ball gear assembly for driving the curtain hanger to rotate. The base also has a rotating hole communicating with the transmission cavity, and at least one side of the base has a disassembly / removal port communicating with the rotating hole. The curtain hanger includes a main shaft portion that can be engaged or disengaged from the rotating hole through the disassembly / removal port and a suspension portion connected to the main shaft portion. When the main shaft portion is engaged in the rotating hole, the main shaft portion is driven by the ball gear assembly, and the main shaft portion engages with the rotating hole, allowing the curtain hanger to rotate around the axis of the main shaft portion.
[0008] In this invention, the base is made of plastic.
[0009] In this utility model, the rotating hole includes a top hole section, an upper hole section, and a lower hole section connected sequentially from top to bottom; the main shaft includes a hanging gear, an upper shaft, and a lower shaft connected sequentially from top to bottom, the hanging gear being rotatably disposed in the top hole section, and the hanging gear being used for meshing and transmission with the ball bearing gear assembly; the upper shaft being rotatably disposed in the upper hole section, and the lower shaft being rotatably disposed in the lower hole section.
[0010] In this utility model, a rotating support surface is formed between the upper hole section and the lower hole section, and a rotating mating surface is provided on the upper shaft, the rotating mating surface sliding against the rotating support surface.
[0011] In this utility model, the disassembly port includes a top opening communicating with the top hole section, an upper opening communicating with the upper hole section, and a lower opening communicating with the lower hole section. The top opening is used for the hanging gear to enter the top hole section, the upper opening is used for the upper shaft to be inserted into or removed from the upper hole section, and the lower opening is used for the lower shaft to be inserted into or removed from the lower hole section.
[0012] In this invention, the width of the upper opening and / or the lower opening gradually decreases along the direction close to the rotating hole.
[0013] In this invention, the width of the end of the upper opening used to connect with the upper hole segment is smaller than the diameter of the upper hole segment and / or the diameter of the upper shaft; and / or, the width of the end of the lower opening used to connect with the lower hole segment is smaller than the diameter of the lower hole segment and / or the diameter of the lower shaft.
[0014] In this invention, the height of the top opening is less than the height of the top hole section, so that the portion of the base above the top opening forms a limiting stop.
[0015] In this utility model, the ball gear assembly includes a worm gear shaft and a gear set. The two opposite walls of the transmission cavity are provided with rotating holes that penetrate the base. The two ends of the worm gear shaft are respectively rotatably fitted in the two rotating holes. The worm gear shaft and the hanging gear are connected by a gear set for transmission.
[0016] In this utility model, the gear set includes a driving gear and a driven gear, both of which are rotatably mounted in the transmission cavity. The driving gear meshes with the worm gear portion of the worm gear shaft, and the driven gear meshes with both the driving gear and the pendant gear.
[0017] The beneficial effects of this utility model are as follows: By setting a disassembly port and a rotation hole on the base, when the curtain hanger is damaged, it can be disassembled from the main shaft through the disassembly port, thereby detaching the curtain hanger from the base. The structure is simple and the disassembly and assembly are convenient, making the installation and replacement of curtain hangers more convenient. No complicated tools or operating procedures are required, and users can complete the maintenance work themselves, effectively reducing maintenance costs and shortening maintenance time. Attached Figure Description
[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments:
[0019] Figure 1 Three-dimensional for vertical curtain hooks Figure 1 ;
[0020] Figure 2 Three-dimensional for vertical curtain hooks Figure 2 ;
[0021] Figure 3 A diagram showing the installation of curtain hangers on the base. Figure 1 ;
[0022] Figure 4 A diagram showing the installation of curtain hangers on the base. Figure 2 ;
[0023] Figure 5 A diagram showing the installation of curtain hangers on the base. Figure 3 ;
[0024] Figure 6 An exploded view of a vertical curtain hook;
[0025] Figure 7 A 3D diagram showing vertical blind hooks installed on a curtain track;
[0026] Figure 8 A schematic diagram showing the connection between the fixed-distance beaded rope and each vertical curtain hook;
[0027] Figure 9 Diagram showing the installation of vertical blind hooks on the curtain track. Figure 1 ;
[0028] Figure 10 Diagram showing the installation of vertical blind hooks on the curtain track. Figure 2 . Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.
[0030] It should be noted that if any directional indication (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial, etc.) is involved in the embodiments of this utility model, the directional indication is only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.
[0031] Furthermore, unless otherwise explicitly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection using welding, a detachable connection using bolts, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0032] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.
[0033] Reference Figure 1-6 A vertical curtain hook includes a base 1 and a curtain hanger 2. The base 1 has a transmission cavity 11, and the transmission cavity 11 has a ball gear assembly 3 for driving the curtain hanger 2 to rotate. The base 1 also has a rotating hole 12 communicating with the transmission cavity 11, the lower end of which extends downward through the base 1. At least one side of the base 1 has a disassembly / removal port 13 extending radially along and communicating with the rotating hole 12. The curtain hanger 2 includes a main shaft portion 21 that can be engaged or disengaged from the rotating hole 12 through the disassembly / removal port 13, and a suspension portion 22 connected to the main shaft portion 21. The suspension portion 22 is used to connect curtain slats 400. When the main shaft portion 21 is engaged in the rotating hole 12, the main shaft portion 21 is connected to the ball gear assembly 3, and the main shaft portion 21 is engaged with the rotating hole 12, allowing the curtain hanger 2 to rotate around the axis of the main shaft portion 21.
[0034] By providing a disassembly port 13 and a rotation hole 12 on the base 1, when the curtain hanger 2 is damaged, the main shaft part 21 can be disassembled from the disassembly port 13, thereby detaching the curtain hanger 2 from the base 1. The structure is simple and easy to disassemble and assemble, making the installation and replacement of the curtain hanger 2 more convenient. No complicated tools or operating procedures are required, and users can complete the maintenance work themselves, effectively reducing maintenance costs and shortening maintenance time.
[0035] In this embodiment, both the base 1 and the curtain hanger 2 are made of plastic, thus possessing a certain degree of elastic deformation capability. During assembly of the main shaft 21, its elastic deformation allows it to smoothly pass through the disassembly port 13 and enter the rotating hole 12. After the main shaft 21 is fully inserted into the rotating hole 12, the base 1 elastically returns to its original shape, enabling the main shaft 21 and the base 1 to engage in a snap-fit connection.
[0036] In this embodiment, the rotating hole 12 includes a top hole section 121, an upper hole section 122, and a lower hole section 123 connected sequentially from top to bottom. A rotating support surface 124 is formed between the upper hole section 122 and the lower hole section 123. The main shaft part 21 includes a hanging gear 211, an upper shaft 212, and a lower shaft 213 connected sequentially from top to bottom. The upper shaft 212 is provided with a rotating mating surface 214. When the main shaft part 21 is inserted into the rotating hole 12, the hanging gear 211 is rotatably disposed in the top hole section 121, the upper shaft 212 is rotatably disposed in the upper hole section 122, and the lower shaft 213 is rotatably disposed in the lower hole section 123, thereby enabling the main shaft part 21 to rotate. The rotating mating surface 214 slides against the rotating support surface 124, so that the rotating support surface 124 supports the rotating mating surface 214, thereby restricting the curtain hanger 2 from falling downward along the axial direction.
[0037] In this embodiment, the suspension part 22 can rotate synchronously with the main shaft part 21, thereby driving the opening and closing angle adjustment of the curtain blade 400. The suspension part 22 is integrally formed on the bottom of the lower shaft 213 of the main shaft part 21, thereby realizing the fixed connection between the suspension part 22 and the main shaft part 21, while reducing production costs and assembly difficulty.
[0038] In this embodiment, the disassembly port 13 includes a top opening 131 communicating with the top hole section 121, an upper opening 132 communicating with the upper hole section 122, and a lower opening 133 communicating with the lower hole section 123. The top opening 131 is used for the hanging gear 211 to enter the top hole section 121, the upper opening 132 is used for the upper shaft 212 to be inserted into or removed from the upper hole section 122, and the lower opening 133 is used for the lower shaft 213 to be inserted into or removed from the lower hole section 123.
[0039] Furthermore, the width of the upper opening 132 and / or the lower opening 133 gradually decreases along the direction close to the rotating hole 12, thereby facilitating the insertion of the spindle portion 21 into the rotating hole 12 and improving installation convenience.
[0040] Furthermore, the width of the end of the upper opening 132 that connects to the upper hole section 122 is smaller than the diameter of the upper hole section 122 and / or the diameter of the upper shaft 212; and / or, the width of the end of the lower opening 133 that connects to the lower hole section 123 is smaller than the diameter of the lower hole section 123 and / or the diameter of the lower shaft 213, so that the main shaft part 21 is engaged with the rotating hole 12 to form a snap-fit, so that the main shaft part 21 will not easily disengage from the rotating hole 12 without the action of external force, thus ensuring the installation stability of the curtain hanger 2.
[0041] Furthermore, the width of the top opening 131 is greater than the diameter of the hanging gear 211, allowing the hanging gear 211 to smoothly enter the top hole section 121. During the assembly of the main shaft 21, the hanging gear 211 first enters the top hole section 121 through the top opening 131, and then the upper shaft 212 and lower shaft 213 sequentially enter the corresponding upper hole section 122 and lower hole section 123 through the upper opening 132 and lower opening 133 respectively. In this way, the width of the top opening 131 is designed to fit the hanging gear 211, so that no additional angle adjustment or excessive external force is required during the assembly process, further improving the installation efficiency and ease of operation. In addition, the height of the top opening 131 is less than the height of the top hole section 121, so that the part of the base 1 above the top opening 131 forms a limiting stop. When the hanging gear 211 is inserted into the top hole section 121, the upper end of the hanging gear 211 is higher than the top of the top opening 131, so that the limiting stop can prevent the hanging gear 211 from coming off upward during rotation, thereby further enhancing the stability of the structure.
[0042] In this embodiment, the hanging gear 211 is used to mesh with the ball bearing gear assembly 3 to achieve transmission during the rotation of the curtain hanging 2. Specifically, the ball bearing gear assembly 3 includes a worm gear shaft 31 and a gear set. Rotation holes 14 penetrating the base 1 are provided on the two opposing walls of the transmission cavity 11. The two ends of the worm gear shaft 31 are rotatably engaged in the two rotation holes 14 respectively. The worm gear shaft 31 and the hanging gear 211 are connected by a gear set for transmission.
[0043] Furthermore, the gear set includes a driving gear 32 and a driven gear 33, both of which are rotatably mounted within the transmission cavity 11. The driving gear 32 meshes with the worm gear portion of the worm gear shaft 31, while the driven gear 33 meshes with both the driving gear 32 and the hanging gear 211. This transmits the rotational motion of the worm gear shaft 31 to the curtain hanging component 2, allowing the curtain hanging component 2 to rotate with the worm gear shaft 31 and achieve light adjustment for the vertical curtain. Additionally, the worm gear shaft 31 has an inner drive hole, which is a hexagonal through hole. This inner drive hole is used to engage with the drive shaft of the vertical curtain. The drive shaft can be driven by a motor or manually, preferably by a beaded cord, to achieve manual drive of the drive shaft.
[0044] In this embodiment, the transmission cavity 11 is provided with a first mounting shaft 15 and a second mounting shaft 16. The driving gear 32 is rotatably mounted on the first mounting shaft 15, and the driven gear 33 is rotatably mounted on the second mounting shaft 16. Both the first mounting shaft 15 and the second mounting shaft 16 are integrally formed and fixed to the cavity wall of the transmission cavity 11. Furthermore, both the driving gear 32 and the driven gear 33 are cylindrical gears, and each of the driving gear 32 and the driven gear 33 has a shaft hole penetrating its thickness direction at its center position. The first mounting shaft 15 is fitted into the shaft hole of the driving gear 32, allowing the driving gear 32 to rotate around the first mounting shaft 15. The second mounting shaft 16 is fitted into the shaft hole of the driven gear 33, allowing the driven gear 33 to rotate around the second mounting shaft 16, thereby achieving stable transmission of the gear set. Furthermore, the first mounting shaft 15 and the second mounting shaft 16 are arranged parallel to each other, and both the first mounting shaft 15 and the second mounting shaft 16 are support columns whose lower ends are integrally formed and connected to the bottom of the transmission cavity 11.
[0045] In this embodiment, the upper end of the transmission cavity 11 is open, and a protective cover 5 for closing the transmission cavity 11 is provided at the upper end opening. The protective cover 5 can be fixed to the base 1 by means of a snap-fit or a bolt connection. The snap-fit installation method of the protective cover 5 can be referred to the relevant description in the invention patent with patent application publication number CN118924096 A, and its specific structure and assembly method will not be described in detail here. In this embodiment, the protective cover 5 is preferably installed by bolt connection to improve the connection strength and stability between the protective cover 5 and the base 1. Specifically, the protective cover 5 is provided with multiple cover plate through holes, and the first mounting shaft 15 and the second mounting shaft 16 are both provided with mounting shaft screw holes corresponding to the cover plate through holes. The cover plate bolts pass through the cover plate through holes in sequence and are connected to the mounting shaft screw holes, thereby fixing the protective cover 5 at the upper opening of the transmission cavity 11, effectively preventing external dust from entering the transmission cavity 11 and preventing it from affecting the normal operation of the gear assembly. At the same time, the protective cover 5 can also restrict the driving gear 32 and the driven gear 33 from disengaging upward from the corresponding mounting shaft, ensuring the installation stability of the driving gear 32 and the driven gear 33.
[0046] Reference Figure 6-10 The base 1 is provided with a linkage mounting position and two linkage clearance holes 17. The linkage mounting position is used to connect the linkage rope 100 of the vertical curtain, so that the linkage rope 100 drives the vertical curtain hooks to move closer and wider. The linkage clearance holes 17 are used for the linkage rope 100 to pass through, thereby supporting the linkage rope 100. Specifically, the linkage rope 100 mounting position includes two mounting rope grooves 18 for accommodating the linkage rope 100. After the linkage rope 100 is wound and embedded in the two mounting rope grooves 18, the linkage rope 100 is locked in the mounting rope grooves 18 of the base 1 by the fixing member 6, ensuring that the connection between the linkage rope 100 and the base 1 is stable and reliable. The fixing member 6 is fixed to the base 1 by locking bolts.
[0047] In this embodiment, the base 1 is provided with a fixed-distance mounting position, which includes at least two fixed-distance slots 19. The fixed-distance slots 19 are arranged at intervals along the moving direction of the vertical curtain hooks. The fixed-distance slots 19 are provided with bead grooves 191. The fixed-distance slots 19 are used to cooperate with the fixed-distance bead rope 200, and the bead grooves 191 are used to cooperate with the round beads 201 of the fixed-distance bead rope 200. When two adjacent vertical curtain hooks are fitted with the fixed-distance bead rope 200, the fixed-distance bead rope 200 is used to limit the maximum unfolding distance between the curtain hooks. In addition, under normal conditions, the base 1 can be connected to a bead 201 of a fixed-distance beaded rope 200 through only one of the fixed-distance slots 19; however, since there are two fixed-distance slots 19, when the fixed-distance beaded rope 200 is broken, the other fixed-distance slot 19 can be connected to a bead 201 of another fixed-distance beaded rope 200. That is, by having the two fixed-distance slots 19 each connect to a bead 201 of a fixed-distance beaded rope 200, the adjacent vertical curtain hooks are re-spaced and linked, so that the entire fixed-distance beaded rope 200 of the same length does not need to be replaced.
[0048] When multiple vertical curtain hooks are slidably installed onto the curtain track 300, the linkage rope 100 is only fixed to the last vertical curtain hook by the fixing piece 6, and the linkage rope 100 is not fixedly connected to the other vertical curtain hooks; specifically, after the linkage rope 100 is wrapped around and embedded in the two mounting rope grooves 18, the linkage rope 100 is locked in the mounting rope groove 18 of the last vertical curtain hook by the fixing piece 6, and then passes through the linkage clearance holes 17 of all vertical curtain hooks to form a ring structure. When the linkage cord 100 is pulled to open the vertical curtain, the last vertical curtain hook is directly driven by the linkage cord 100 to move in the direction of opening the curtain slats 400. Since the vertical curtain hooks are connected at a fixed distance by the fixed-distance beaded cord 200, as the last vertical curtain hook moves in the direction of opening the curtain slats 400, the fixed-distance beaded cord 200 also moves the other vertical curtain hooks in the same direction. When the linkage cord 100 is pulled to close the vertical curtain, the last vertical curtain hook is directly driven by the linkage cord 100 to move in the direction of closing the curtain slats 400. During this process, the last vertical curtain hook pushes the other vertical curtain hooks to retract in the direction of closing the curtain slats 400.
[0049] In addition, the curtain track 300 includes a track body 301 and a front stop 302 and a rear stop 303 located at the lower end of the track body 301. The bottom of the front stop 302 is lower than the bottom of the rear stop 303. The front stop 302 is provided with a front support portion located at the bottom rear side of the front stop 302. The upper part of the front support portion is provided with a guide portion 304. The base 1 is provided with a guide groove 10 adapted to the guide portion 304. The guide groove 10 slides in cooperation with the guide portion 304. The rear stop 303 is provided with a rear support portion 305. The base 1 is provided with a cooperating extension portion that slides on the upper part of the rear support portion 305. The front and rear sides of the base 1 are close to or slide on the inner sides of the front stop 302 and the rear stop 303, respectively, so that the base 1 can slide smoothly along the extension direction of the curtain track 300. In addition, since the bottom of the front baffle 302 is lower than the bottom of the rear baffle 303, a notch can be provided on the upper front side of the curtain slat 400 to avoid the lower end of the front baffle 302, so that the top of the curtain slat 400 can be hidden behind the front baffle 302, thereby achieving an overall flat and beautiful appearance when the curtain is closed, and there is no light-transmitting gap between the curtain track 300 and the curtain slat 400.
[0050] The above description is only a preferred embodiment of the present utility model. Any technical solution that achieves the purpose of the present utility model by essentially the same means shall fall within the protection scope of the present utility model.
Claims
1. A vertical curtain hook, comprising a base (1) and a curtain hanger (2), wherein the base (1) is provided with a transmission cavity (11), and the transmission cavity (11) is provided with a ball gear assembly (3) for driving the curtain hanger (2) to rotate; characterized in that: The base (1) is also provided with a rotating hole (12) communicating with the transmission cavity (11). The base (1) has at least one side provided with a disassembly port (13) communicating with the rotating hole (12). The curtain hanger (2) includes a main shaft part (21) that can be inserted into or removed from the rotating hole (12) through the disassembly port (13) and a suspension part (22) connected to the main shaft part (21). When the main shaft part (21) is inserted into the rotating hole (12), the main shaft part (21) is connected to the ball gear assembly (3) for transmission. The main shaft part (21) is engaged with the rotating hole (12). The curtain hanger (2) can rotate around the axis of the main shaft part (21).
2. A vertical curtain hook according to claim 1, characterized in that: The base (1) is made of plastic.
3. A vertical curtain hook according to claim 1 or 2, characterized in that: The rotating hole (12) includes a top hole section (121), an upper hole section (122), and a lower hole section (123) connected sequentially from top to bottom; the main shaft (21) includes a hanging gear (211), an upper shaft (212), and a lower shaft (213) connected sequentially from top to bottom. The hanging gear (211) is rotatably disposed in the top hole section (121) and is used to mesh with the ball gear assembly (3) for transmission; the upper shaft (212) is rotatably disposed in the upper hole section (122), and the lower shaft (213) is rotatably disposed in the lower hole section (123).
4. A vertical curtain hook according to claim 3, characterized in that: A rotating support surface (124) is formed between the upper hole section (122) and the lower hole section (123). A rotating mating surface (214) is provided on the upper shaft (212). The rotating mating surface (214) slides against the rotating support surface (124).
5. A vertical curtain hook according to claim 4, characterized in that: The disassembly / assembly port (13) includes a top opening (131) communicating with the top hole section (121), an upper opening (132) communicating with the upper hole section (122), and a lower opening (133) communicating with the lower hole section (123). The top opening (131) is used for the pendant gear (211) to enter the top hole section (121). The upper opening (132) is used for the upper shaft (212) to be inserted into or removed from the upper hole section (122). The lower opening (133) is used for the lower shaft (213) to be inserted into or removed from the lower hole section (123).
6. A vertical curtain hook according to claim 5, characterized in that: The width of the upper opening (132) and / or the lower opening (133) gradually decreases in the direction close to the rotating hole (12).
7. A vertical curtain hook according to claim 6, characterized in that: The width of the upper opening (132) at the end connected to the upper hole segment (122) is less than the diameter of the upper hole segment (122) and / or the diameter of the upper shaft (212); and / or, the width of the lower opening (133) at the end connected to the lower hole segment (123) is less than the diameter of the lower hole segment (123) and / or the diameter of the lower shaft (213).
8. A vertical curtain hook according to claim 6, characterized in that: The height of the top opening (131) is less than the height of the top hole section (121), so that the base (1) forms a limiting stop above the top opening (131).
9. A vertical curtain hook according to claim 3, characterized in that: The ball bearing assembly (3) includes a worm gear shaft (31) and a gear set. The two opposite walls of the transmission cavity (11) are provided with rotating holes (14) that penetrate the base (1). The two ends of the worm gear shaft (31) are respectively rotatably fitted in the two rotating holes (14). The worm gear shaft (31) and the hanging gear (211) are connected by a gear set for transmission.
10. A vertical curtain hook according to claim 9, characterized in that: The gear set includes a driving gear (32) and a driven gear (33), both of which are rotatably mounted in the transmission cavity (11). The driving gear (32) meshes with the worm gear part of the worm gear shaft (31), and the driven gear (33) meshes with both the driving gear (32) and the pendant gear (211).