Rotating shoelace tightening / loosening buckle

Abstract

The present invention relates to the field of rotating shoelace buckles, and in particular relates to a rotating shoelace tightening / loosening buckle, comprising a fixed base. A mounting base capable of accommodating a shoelace is provided at an upper end of the fixed base, a shoelace winding device capable of winding and rotating the shoelace is mounted inside of the mounting base, a fixed housing capable of driving the shoelace winding device to rotate is provided on the exterior of the shoelace winding device, and an upper rotating cover capable of rebounding is engaged with an outer side of the fixed housing. The present invention employs multiple tightly combined components including the fixed base, the mounting base, the shoelace take-up device, the fixed housing, and the upper rotating cover, thereby ensuring structural stability and durability. The engagement and meshing design among the components enables smooth rotation and operations for the overall device, not being susceptible to failure or looseness. A meshing connection between a recessed tooth block and a protruding tooth block not only increases the connection strength between the fixed housing and the shoelace winding device, but also improves the smoothness of rotation between the two components.

Description

Rotary fastener for shoes TECHNICAL FIELD

[0001] The present application relates to the field of rotary shoe fastener, in particular to a rotary fastener for shoes. BACKGROUND

[0002] The shoelace is used to adjust the tightness of the upper, and protect the comfort of the foot. The shoelace has always been tied by crossing and knotting. The shoelace crossing and knotting method is very cumbersome, and the shoelace often appears too tight, too loose and loose during walking and exercising, causing a lot of inconvenience.

[0003] Children usually tie shoelaces with the help of adults. Many children simply do not tie shoelaces once the shoelaces are dropped, so the child often steps on the shoelace and falls down. TECHNICAL PROBLEM

[0004] The current shoelace fastener cannot be rebounded, and children often unbend it when using, which is not convenient. Therefore, a rotary fastener for shoes is provided. TECHNICAL SCHEME

[0005] The purpose of the present application is to provide a rotary fastener for shoes to solve the problems in the background art.

[0006] To achieve the above purpose, a rotary fastener for shoes comprises a fixed base, the upper end of the fixed base is provided with a mounting seat capable of accommodating a shoelace, the inside of the mounting seat is provided with a take-up device capable of winding and rotating the shoelace, the outside of the take-up device is provided with a fixed shell capable of driving the take-up device to rotate, and the outside of the fixed shell is provided with a rotary upper cover capable of rebounding.

[0007] Preferably, the fixed base comprises a notch, a groove S, a protrusion S, a buckle groove A and a buckle groove B, the notch is arranged on the outer wall of the fixed base, the fixed base is fixedly installed on the vamp, the shoelace is inserted into the inside of the fixed base, the protrusion S is integrally connected to the upper surface of the fixed base, the groove S is arranged in the inside of the protrusion S, the number of the groove S is two, the buckle groove A and the buckle groove B are arranged at the bottom of the fixed base, and the buckle groove A and the buckle groove B are communicated.

[0008] Preferably, the mounting base comprises a rack edge, a wire entry protrusion, a buckle B and a buckle A, the mounting base is clamped in the inside of the fixed base through the buckle B and the buckle A, the buckle B and the buckle A are integrally connected at the bottom of the mounting base, the size of the buckle B is matched with the size of the buckle slot B, the buckle B is clamped with the buckle slot B, the size of the buckle A is matched with the size of the buckle slot A, the buckle A is clamped with the buckle slot A, the wire entry protrusion is integrally connected on the outer wall of the mounting base, the number of the wire entry protrusion is two, the wire entry protrusion is installed in the inside of the groove S, the rack edge is integrally connected on the inner wall of the mounting base, the rack edge is engaged with the gear on the take-up device, so that when the take-up device rotates, the rack edge can drive the mounting base to rotate together, thereby realizing automatic winding and storage of the shoelace. The rotating cover comprises a cover body, a torsional spring and anti-skid lines.

[0009] In use, the user only needs to pass the shoelace through the fixed base and the mounting base, and then rotate the take-up device, so as to realize automatic winding and storage of the shoelace.

[0010] Preferably, the take-up device comprises a center cylinder, a tooth block and a wire entry hole, the take-up device is rotatably connected in the inside of the mounting base, the center cylinder is fixedly connected at the top of the take-up device, the tooth block is integrally connected on the surface of the center cylinder, the number of the tooth block is two, the wire entry hole is opened on the outer wall of the take-up device and is oppositely arranged, the wire entry hole is two groups, each group has four holes, through the arrangement of the wire entry hole, the bottom of the shoelace can be fixed in the inside of the take-up device, which is convenient for winding the shoelace, through the arrangement of the wire entry protrusion, the shoelace can be wound, which is convenient for use, and the number of the wire entry protrusion is only two, which can more conveniently wind the shoelace.

[0011] Preferably, the fixed shell comprises an arc-shaped groove, a convex clamping block, a central groove, a concave tooth block, a fixed clamping edge and an arc-shaped clamping block, the fixed shell is clamped on the top of the take-up device through the central groove, the central groove is arranged in the middle of the fixed shell, the size of the central groove is matched with the size of the central cylinder, the central cylinder is arranged in the central groove, the arc-shaped grooves are arranged on the surface of the fixed shell, the number of the arc-shaped grooves is three, the convex clamping blocks are integrally connected to the outer wall of the fixed shell, the number of the convex clamping blocks is three, the concave tooth blocks are integrally connected to the inner wall of the arc-shaped grooves, the concave tooth blocks are meshed with the convex tooth blocks, the fixed clamping edges are fixedly connected to the bottom of the inner wall of the fixed shell, the number of the fixed clamping edges is three, the fixed clamping edges are clamped on the outer side of the mounting seat, the arc-shaped clamping blocks are integrally connected to one end of the concave tooth blocks, the arc-shaped clamping blocks are meshed with the rack edges, the shape of the arc-shaped clamping blocks is arc-shaped, the rack is arranged at the end, and the clamping teeth of the rack edge cooperate with the arc-shaped clamping blocks to emit precise mechanical sound, which not only improves the use comfort of the user, but also conveniently winds the shoelaces.

[0012] Preferably, the rotating upper cover comprises an arc-shaped protrusion and a clamping block groove, the rotating upper cover is clamped on the outer side of the fixed shell through the clamping block groove, the clamping block groove is arranged on the inner wall of the rotating upper cover, the number of the clamping block grooves is three, the arc-shaped protrusions are fixedly connected to the inner wall of the top of the rotating upper cover, the number of the arc-shaped protrusions is three, and the arc-shaped protrusions are clamped in the arc-shaped grooves. Beneficial effects

[0013] Compared with the prior art, the beneficial effects of the present application are:

[0014] Through ingenious structural design, the present application realizes automatic winding and storage of shoelaces, greatly improves the convenience of putting on and taking off shoes. Users only need to simply operate the take-up device to easily complete the winding and fixing of the shoelaces, without manually performing the tedious shoelace tying steps, saving time and effort, and being convenient and fast.

[0015] The present application adopts the close combination of a fixed base, a mounting seat, a take-up device, a fixed shell and a rotating upper cover and the like, ensuring the stability and durability of the structure. The clamping and meshing design between the components makes the whole device more smooth when rotating and operating, and is not prone to failure or loosening.

[0016] The meshing connection of the concave tooth block and the convex tooth block not only increases the connection strength between the fixing shell and the take-up device, but also makes the rotation between the fixing shell and the take-up device more smooth. The design not only guarantees the stability of the device, but also improves the service life of the device. The rack edge is located on the inner wall of the mounting seat, can be matched with the corresponding gear structure, and realizes accurate rotation and positioning. The design not only improves the operation accuracy of the device, but also enhances the stability and durability of the device. BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1 is a schematic diagram of the overall structure of the present application;

[0018] Fig. 2 is an explosion schematic diagram of the present application;

[0019] Fig. 3 is a schematic diagram of the structure of the mounting seat and the fixing shell of the present application;

[0020] Fig. 4 is a perspective view of the present application.

[0021] In the figure: 1, fixed base; 2, mounting seat; 3, take-up device; 4, fixing shell; 5, rotating upper cover; 11, notch; 12, groove S; 13, protrusion S; 14, buckle groove A; 15, buckle groove B; 21, rack edge; 22, wire entry protrusion; 23, buckle B; 24, buckle A; 31, center cylinder; 32, convex tooth block; 33, wire entry hole; 41, arc-shaped groove; 42, convex buckle; 43, center groove; 44, concave tooth block; 45, fixed buckle edge; 46, arc-shaped buckle; 51, arc-shaped protrusion; 52, buckle groove. Embodiment of the present application

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0023] Please refer to Figs. 1-4, a rotating elastic shoe buckle in the figure includes a fixed base 1, the upper end of the fixed base 1 is provided with a mounting seat 2 capable of accommodating a shoelace, the inside of the mounting seat 2 is provided with a take-up device 3 capable of winding and rotating the shoelace, the outside of the take-up device 3 is provided with a fixing shell 4 capable of driving the take-up device 3 to rotate, and the outside of the fixing shell 4 is provided with a rotating upper cover 5 capable of rebounding.

[0024] The design of the rotating shoelace buckle is ingenious and practical, not only convenient for storing the shoelace, but also can realize the tightness adjustment of the shoelace through simple operation. The inside of the take-up device 3 is provided with a precise gear structure, which can drive the gear inside the take-up device 3 to rotate through the rotation of the fixed shell 4, so as to realize the winding and tightening of the shoelace. At the same time, the material of the take-up device 3 is high-strength plastic, which not only ensures the durability, but also reduces the overall weight.

[0025] The rotating upper cover 5 is made of elastic material and has good resilience. Even if the child accidentally pries it open, the rotating upper cover 5 will not be removed, but will bounce back, which is very convenient. When the shoelace tightness needs to be adjusted, just press the rotating upper cover 5 lightly to release the locking of the fixed shell 4, and then rotate the fixed shell 4 to achieve adjustment.

[0026] The design of the rotating shoelace buckle is not only convenient and practical, but also fashionable and generous in appearance, which can be matched with various styles of shoes. Whether it is sports shoes, casual shoes or leather shoes, it can show unique personality and taste.

[0027] The fixed base 1 includes a notch 11, a groove S12, a protrusion S13, a buckle groove A14 and a buckle groove B15. The notch 11 is provided on the outer wall of the fixed base 1, the fixed base 1 is fixedly installed on the vamp, the inside of the fixed base 1 is inserted with a shoelace, the protrusion S13 is integrally connected to the upper surface of the fixed base 1, the groove S12 is provided in the inside of the protrusion S13, the number of the groove S12 is two, the buckle groove A14 and the buckle groove B15 are provided at the bottom of the fixed base 1, and the buckle groove A14 and the buckle groove B15 are communicated.

[0028] Specifically, the notch 11 is carefully selected in position, which is convenient for user operation and can maintain the overall beauty of the fixed base 1. The size of the notch 11 is also accurately calculated to ensure that the shoelace can pass through smoothly, while providing sufficient fixing force to prevent the shoelace from loosening.

[0029] The design of the protrusion S13 not only increases the stability of the fixed base 1, but also provides additional comfort for the user. It is integrally connected to the upper surface of the fixed base 1, which ensures the stability and durability of the structure. The communication design of the buckle groove A14 and the buckle groove B15 makes the structure more easy to install and disassemble.

[0030] The mounting seat 2 comprises a rack edge 21, a wire entry protrusion 22, a buckle B 23 and a buckle A 24. The mounting seat 2 is clamped in the interior of the fixed base 1 through the buckle B 23 and the buckle A 24. The buckle B 23 and the buckle A 24 are integrally connected to the bottom of the mounting seat 2. The size of the buckle B 23 is matched with the size of the buckle groove B 15. The buckle B 23 is clamped with the buckle groove B 15. The size of the buckle A 24 is matched with the size of the buckle groove A 14. The buckle A 24 is clamped with the buckle groove A 14. The wire entry protrusion 22 is integrally connected to the outer wall of the mounting seat 2. The number of the wire entry protrusion 22 is two. The wire entry protrusion 22 is installed in the groove S 12. The rack edge 21 is integrally connected to the inner wall of the mounting seat 2.

[0031] Specifically, the design of the mounting seat 2 is unique and practical. The ingenious combination of the rack edge 21, the wire entry protrusion 22, the buckle B 23 and the buckle A 24 makes the entire installation process simple and stable. The rack edge 21 is located on the inner wall of the mounting seat 2 and can cooperate with the corresponding gear structure to achieve precise rotation and positioning. This design not only improves the operation accuracy of the equipment, but also enhances its stability and durability.

[0032] The wire entry protrusion 22 is another important part of the mounting seat 2. They are integrally connected to the outer wall of the mounting seat 2 and the number is two. The design of the wire entry protrusion 22 is cleverly adapted to the shape of the groove S 12, so that the mounting seat 2 can be stably installed on the fixed base 1. This structure not only simplifies the installation process, but also improves the overall stability of the equipment.

[0033] The buckle B 23 and the buckle A 24 are the key parts of the mounting seat 2. They are integrally connected to the bottom of the mounting seat 2 and are matched with the buckle groove B 15 and the buckle groove A 14 of the fixed base 1 respectively. The design of the buckle makes the mounting seat 2 clamped in the interior of the fixed base 1 conveniently and quickly without using additional tools or screws. This design not only improves the installation efficiency, but also makes the disassembly and maintenance of the equipment more simple.

[0034] The take-up device 3 comprises a center cylinder 31, a protruding tooth block 32 and a wire entry hole 33. The take-up device 3 is rotationally connected in the interior of the mounting seat 2. The center cylinder 31 is fixedly connected to the top of the take-up device 3. The protruding tooth block 32 is integrally connected to the surface of the center cylinder 31. The number of the protruding tooth block 32 is two. The wire entry hole 33 is opened on the outer wall of the take-up device 3 and is oppositely arranged. The wire entry hole 33 is two groups, each group has four holes.

[0035] Specifically, the design of the take-up device 3 is ingenious and practical, not only effectively solves the problem of shoelace storage, but also makes the whole device more neat and beautiful. The center column 31 as the core part of the take-up device 3 stably supports the whole structure and ensures the smooth rotation of the take-up device 3. The design of the convex tooth block 32 enhances the stability of the connection between the take-up device 3 and the mounting seat 2, and the number is set to two, which not only ensures sufficient connection strength, but also avoids too many convex tooth blocks leading to too complex structure.

[0036] The fixed shell 4 includes an arc-shaped groove 41, a convex clamping block 42, a center groove 43, a concave tooth block 44, a fixed clamping edge 45 and an arc-shaped clamping block 46. The fixed shell 4 is clamped at the top of the take-up device 3 through the center groove 43, the center groove 43 is opened in the middle of the fixed shell 4, the size of the center groove 43 is matched with the size of the center column 31, the center column 31 is arranged inside the center groove 43, the arc-shaped groove 41 is opened on the surface of the fixed shell 4, the number of the arc-shaped groove 41 is three, the convex clamping block 42 is integrally connected to the outer wall of the fixed shell 4, the number of the convex clamping block 42 is three, the concave tooth block 44 is integrally connected to the inner wall of the arc-shaped groove 41, the concave tooth block 44 is engaged with the convex tooth block 32, the fixed clamping edge 45 is fixedly connected to the bottom of the inner wall of the fixed shell 4, the number of the fixed clamping edge 45 is three, the fixed clamping edge 45 is clamped to the outside of the mounting seat 2, and the arc-shaped clamping block 46 is integrally connected to one end of the concave tooth block 44. The arc-shaped clamping block 46 is engaged with the rack edge 21, the shape of the arc-shaped clamping block 46 is arc-shaped, and the end portion is provided with a rack.

[0037] Specifically, the design of the fixed shell 4 is ingenious and practical, and the cooperation of each part makes the whole device run stably and efficiently. The arrangement of the arc-shaped groove 41 not only enhances the structural strength of the fixed shell 4, but also provides convenience for the installation of other parts. The existence of the convex clamping block 42 makes the fixed shell 4 more stably fixed on the top of the take-up device 3, preventing shaking or falling during use.

[0038] The close cooperation between the center groove 43 and the center column 31 forms a stable connection between the take-up device 3 and the fixed shell 4. This design not only ensures the normal work of the take-up device 3, but also makes the whole device more beautiful.

[0039] In particular, the engagement connection between the concave tooth block 44 and the convex tooth block 32 not only increases the connection strength between the fixed shell 4 and the take-up device 3, but also makes the rotation between the two more smooth. This design not only ensures the stability of the device, but also improves its service life.

[0040] The engagement of the arc-shaped clamping block 46 with the rack edge 21 allows the fixed shell 4 to rotate with the mounting base 2, thereby achieving the winding and unwinding function of the cord winder 3. The shape of the arc-shaped clamping block 46 and the rack design make it have good wear resistance and durability, and can work stably for a long time.

[0041] The rotating upper cover 5 includes arc-shaped protrusions 51 and clamping block grooves 52. The rotating upper cover 5 is clamped on the outside of the fixed shell 4 through the clamping block grooves 52, which are opened on the inner wall of the rotating upper cover 5. The number of clamping block grooves 52 is three. The arc-shaped protrusions 51 are fixedly connected to the inner wall of the top of the rotating upper cover 5. The number of arc-shaped protrusions 51 is three. The arc-shaped protrusions 51 are clamped inside the arc-shaped grooves 41. The size of the arc-shaped protrusions 51 is matched with the size of the arc-shaped grooves 41.

[0042] Specifically, the design of the rotating upper cover 5 is full of practicality and delicacy. The arrangement of the arc-shaped protrusions 51 not only makes the rotating upper cover 5 more stable when closed, but also provides an intuitive rotation direction indication for the user. The clever combination of the clamping block grooves 52 and the arc-shaped grooves 41 further enhances the connection strength between the rotating upper cover 5 and the fixed shell 4, making the entire structure stable and durable.

[0043] When the user needs to open or close the rotating upper cover 5, he or she only needs to rotate it slightly. The arc-shaped protrusions 51 will drive the arc-shaped grooves 41 to rotate, and at the same time, the clamping block grooves 52 will cooperate with the clamping blocks on the outside of the fixed shell 4, thereby achieving quick and stable connection. This design not only simplifies the operation process, but also improves the user experience of the product.

[0044] Working principle and process: When the device needs to be used, first make sure that the fixed base 1 has been securely installed in the desired position. Then, align the wire entry protrusion 22 of the mounting base 2 with the groove S12 of the fixed base 1, and match the buckle B23 and the buckle A24 with the buckle groove B15 and the buckle groove A14 of the fixed base 1, to achieve quick installation of the mounting base 2. The rack edge 21 of the mounting base 2 cooperates with the gear structure of the fixed base 1 to achieve accurate rotation and positioning.

[0045] Once the mounting base 2 is installed, the cord winder 3 can start working. The arc-shaped protrusions 51 of the rotating upper cover 5 cooperate with the arc-shaped grooves 41 of the fixed shell 4 to easily open or close the rotating upper cover 5. When the shoelace needs to be stored, the shoelace is passed through the wire entry hole 33 of the cord winder 3 and the cord winder 3 is rotated to store the shoelace. At this time, the engagement of the protruding teeth block 32 and the recessed teeth block 44 ensures the stable rotation of the cord winder 3.

[0046] During the rotation of the take-up device 3, the arc-shaped clamping block 46 of the fixed shell 4 is in meshing connection with the rack edge 21 of the mounting base 2, so that the fixed shell 4 can rotate with the rotation of the mounting base 2. This design not only ensures the smooth rotation of the take-up device 3, but also makes the whole device more stable during rotation.

[0047] It should be noted that the relational terms herein such as first and second and the like are used solely to distinguish one from another entity or action without necessarily requiring or implying that there is any such relationship or order between such entities or actions. Also, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0048] While the embodiments of the application have been illustrated and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and alterations can be made therein without departing from the spirit and scope of the application, which is defined by the appended claims and their equivalents.

Claims

1. A rotary elastic shoe fastener comprising a fixed base (1), characterized in that: The upper end of the fixed base (1) is provided with a mounting seat (2) capable of accommodating the shoelace, the inside of the mounting seat (2) is provided with a take-up device (3) capable of winding and rotating the shoelace, the outside of the take-up device (3) is provided with a fixed shell (4) capable of driving the take-up device (3) to rotate, and the outside of the fixed shell (4) is clamped with a rotating upper cover (5) capable of rebounding.

2. A rotary slip-on shoe fastener according to claim 1, wherein: The fixed base (1) comprises a notch (11), a groove S (12), a protrusion S (13), a buckle groove A (14) and a buckle groove B (15), the notch (11) is arranged on the outer wall of the fixed base (1), the fixed base (1) is fixedly installed on the vamp, the shoelace is inserted into the fixed base (1), the protrusion S (13) is integrally connected to the upper surface of the fixed base (1), the groove S (12) is arranged in the inside of the protrusion S (13), the number of the groove S (12) is two, the buckle groove A (14) and the buckle groove B (15) are arranged at the bottom of the fixed base (1), and the buckle groove A (14) and the buckle groove B (15) are communicated.

3. A rotary slip-on shoe fastener according to claim 1, wherein: The mounting seat (2) comprises a rack edge (21), a wire entry protrusion (22), a buckle B (23) and a buckle A (24), the mounting seat (2) is clamped in the inside of the fixed base (1) through the buckle B (23) and the buckle A (24), the buckle B (23) and the buckle A (24) are integrally connected to the bottom of the mounting seat (2), the size of the buckle B (23) is matched with the size of the buckle groove B (15), the buckle B (23) is clamped with the buckle groove B (15), the size of the buckle A (24) is matched with the size of the buckle groove A (14), the buckle A (24) is clamped with the buckle groove A (14), the wire entry protrusion (22) is integrally connected to the outer wall of the mounting seat (2), the number of the wire entry protrusion (22) is two, the wire entry protrusion (22) is installed in the groove S (12), and the rack edge (21) is integrally connected to the inner wall of the mounting seat (2).

4. The rotary slip-on shoe fastener according to claim 1, wherein: The take-up device (3) comprises a center cylinder (31), a protruding tooth block (32) and a wire entry hole (33), the take-up device (3) is rotatably connected to the inside of the mounting seat (2), the center cylinder (31) is fixedly connected to the top of the take-up device (3), the protruding tooth block (32) is integrally connected to the surface of the center cylinder (31), the number of the protruding tooth block (32) is two, the wire entry hole (33) is arranged on the outer wall of the take-up device (3) and is oppositely arranged, and the wire entry hole (33) is two groups, each group has four holes.

5. The rotary slip-on shoe fastener according to claim 1, wherein: The fixed shell (4) comprises an arc-shaped groove (41), a convex clamping block (42), a central groove (43), a concave tooth block (44), a fixed clamping edge (45) and an arc-shaped clamping block (46), the fixed shell (4) is clamped on the top of the take-up device (3) through the central groove (43), the central groove (43) is arranged in the middle of the fixed shell (4), the size of the central groove (43) is matched with the size of the central cylinder (31), the central cylinder (31) is arranged in the central groove (43), the arc-shaped groove (41) is arranged on the surface of the fixed shell (4), the number of the arc-shaped groove (41) is three, the convex clamping block (42) is integrally connected to the outer wall of the fixed shell (4), the number of the convex clamping block (42) is three, the concave tooth block (44) is integrally connected to the inner wall of the arc-shaped groove (41), the concave tooth block (44) is in meshing connection with the convex tooth block (32), the fixed clamping edge (45) is fixedly connected to the bottom of the inner wall of the fixed shell (4), the number of the fixed clamping edge (45) is three, the fixed clamping edge (45) is clamped on the outer side of the mounting seat (2), the arc-shaped clamping block (46) is integrally connected to one end of the concave tooth block (44), the arc-shaped clamping block (46) is in meshing connection with the rack edge (21), the shape of the arc-shaped clamping block (46) is arc-shaped, and the rack is arranged at the end.

6. A rotary slip-on shoe fastener according to claim 1, wherein: The rotating upper cover (5) comprises an arc-shaped protrusion (51) and a clamping block groove (52), the rotating upper cover (5) is clamped on the outer side of the fixed shell (4) through the clamping block groove (52), the clamping block groove (52) is arranged on the inner wall of the rotating upper cover (5), the number of the clamping block groove (52) is three, the arc-shaped protrusion (51) is fixedly connected to the inner wall of the top of the rotating upper cover (5), the number of the arc-shaped protrusion (51) is three, the arc-shaped protrusion (51) is clamped in the arc-shaped groove (41), and the size of the arc-shaped protrusion (51) is matched with the size of the arc-shaped groove (41).

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