PP flexible field operation environment-friendly optical cable protection device

Abstract

The invention discloses a PP flexible field operation environment-friendly optical cable protection device, and relates to the technical field of electric power wire hanging tools. A PP flexible field operation environment-friendly optical cable protection device comprises a supporting placing arm, an arc-shaped arm, a supporting boss, a connecting arm, a limiting claw, an annular lock cavity and an air cushion. When the arc-shaped arms on the two sides of the supporting and placing arms rotate through the first connecting shafts till the limiting claws are closed, the steel strand is stably clamped, falling off due to external force or vibration is prevented, the structural safety and reliability are improved, meanwhile, in the closing process of the arc-shaped arms, a cam can be driven to drive an air stirring assembly to work in a linkage mode, an air cushion is inflated and expanded, and the safety of the steel strand is improved. The optical cable is supported and stably clamped between the air cushion and the two supporting bosses, a triangular clamping area is formed, the optical cable leaves the base surface of the supporting and placing arm, a non-contact suspension state is formed, the problems of frictional wear and water retention are effectively solved, and the durability and reliability of the optical cable are remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of electric power line hanging tools, and in particular relates to a PP flexible field environmentally friendly optical cable protection device. Background Art

[0002] In the fields of communications and power transmission, the installation of optical cables and electrical wires is a key link in ensuring the stable transmission of signals and power.

[0003] Traditional cable installation methods usually rely on steel strands as support structures, and cables are hung on the steel strands by winding metal wires or hooks. However, this method has many problems: first, the traditional hook design is complex and easy to slip during installation, especially when working at heights, which not only increases the difficulty of operation but also may cause safety hazards. Secondly, direct contact between the cable and the support structure will cause friction and wear, which may damage the cable sheath in the long run and even affect the performance of the internal optical fiber or wire. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a PP flexible field environmentally friendly optical cable protection device that can overcome the above problems or at least partially solve the above problems.

[0005] In order to solve the above technical problems, the basic concept of the technical solution adopted by the present invention is: a PP flexible field environmentally friendly optical cable protection device, including a supporting placement arm that fits the surface of the optical cable, the supporting placement arm is provided with a limiting member suspended on the external steel strand, the limiting member includes a pair of arc-shaped arms, and the arc-shaped arm is provided with a supporting boss, one side of the arc-shaped arm is rotatably arranged on the supporting placement arm, and the other side is fixedly connected to a connecting arm, and the connecting arm is fixedly connected to a limiting claw, when the two arc-shaped arms rotate around the supporting placement arm to a locking position, the limiting claws at their ends overlap with each other to form an annular locking cavity matching the outer diameter of the steel strand, and at the same time, an air cushion built into the supporting placement arm is linked to trigger the air cushion to be inflated and form a triangular support with the supporting boss, so as to lift the optical cable away from the base surface of the supporting placement arm to form a non-contact suspended state.

[0006] Preferably, the base surface of the supporting placement arm in contact with the optical cable is an arc-shaped structure, and a pair of first rotating grooves are provided on the supporting placement arm. A first connecting shaft is rotatably arranged between the inner walls of the first rotating grooves, and one side of the arc-shaped arm is fixedly connected to the first connecting shaft.

[0007] Preferably, the two connecting arms are in a vertical shape after being overlapped, and a thread groove is provided on the connecting arm, and a locking screw is threadedly connected to the inner wall of the thread groove.

[0008] Preferably, one of the limiting claws is provided with an arc-shaped pre-tightening groove, to which a matching magnetic sheet is fixedly connected, and the other limiting claw is fixedly connected with an arc-shaped iron block attracted to the magnetic sheet.

[0009] Preferably, a pair of cams are fixedly connected to the first connecting shaft, and the surfaces of the cams are linked with an air-displacing assembly connected to the air cushion.

[0010] Preferably, the air deflector assembly includes an air duct, one end of the air duct is connected to the air inlet head on the air cushion, the other end of the air duct is connected to an air deflector, the inner wall of the air deflector is fitted with a matching compression block, a return spring is fixedly connected between the bottom of the compression block and the bottom wall of the air deflector, the top of the compression block is fixedly connected to a deflector rod, and one end of the deflector rod extending to the top of the air deflector is fixedly connected to a semicircular deflector block fitted with a cam surface.

[0011] Preferably, the air cushion is located at the center of the base surface of the supporting placement arm, and the supporting placement arm is connected to evenly distributed arc flow grooves.

[0012] Preferably, a pair of T-shaped mounting plates are fixedly connected to the supporting and placing arms, and a mounting ring is fixedly connected between the T-shaped mounting plates and the surface of the air pump.

[0013] Preferably, when the support boss and the arc-shaped arm are rotatably arranged, they include a second rotation groove opened on the arc-shaped arm, a second connecting shaft is fixedly connected between the inner walls of the second rotation groove, and the support boss is rotatably connected to the second connecting shaft.

[0014] Preferably, a circular cavity is provided inside the supporting boss, a connecting rope corresponding to the inside of the circular cavity is fixedly connected to the second connecting shaft, an impact ball is fixedly connected to the end of the connecting rope, a plurality of arc-shaped metal sheets distributed in a circle are fixedly connected to the inner wall of the circular cavity, and an open groove corresponding to the arc-shaped metal sheet is connected to the surface of the supporting boss.

[0015] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0016] 1. When the arc-shaped arms on both sides of the supporting arm are rotated through the first connecting shaft until the two limit claws are closed, the steel strands are stably clamped. This design can effectively prevent the steel strands from falling off due to external force or vibration, thereby improving the safety and reliability of the structure. At the same time, the closing process of the arc-shaped arms can be used to drive the cam on the first connecting shaft to drive the air guide tube, air cylinder, compression block, return spring, toggle rod, semicircular toggle block and other structures to work in linkage to achieve inflation of the air cushion. The inflated air cushion expands and can lift up the optical cable originally attached to the base surface of the supporting arm, so that the optical cable can be stably clamped between the air cushion and the two supporting bosses to form a stable triangular clamping area. At the same time, the optical cable leaves the base surface of the supporting arm to form a non-contact suspended state. This design effectively solves the problem of performance degradation of the optical cable due to friction, wear and moisture retention, thereby improving the durability and reliability of the optical cable.

[0017] 2. By setting the supporting boss and the arc-shaped arm to be rotatably connected, not only can the supporting boss be able to adapt to the movement of the optical cable and avoid the problem of aggravated friction caused by the fixed connection of the supporting boss, but also the rotation process of the supporting boss can be used to make the arc-shaped metal sheet collide with the impact ball to make a sound. Then, the sound is transmitted through the opening groove to serve as a warning or bird-repelling effect, thereby preventing birds from damaging the optical cable or the supporting structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In the attached picture:

[0019] Figure 1 This is a first structural schematic diagram of a PP flexible field environmentally friendly optical cable protection device proposed by the present invention;

[0020] Figure 2 This is a second structural schematic diagram of a PP flexible field environmentally friendly optical cable protection device proposed by the present invention;

[0021] Figure 3 For the present invention Figure 1 Schematic diagram of the unfolded structure of the middle arc arm;

[0022] Figure 4 For the present invention Figure 1 Schematic diagram of the closed structure of the middle arc arm;

[0023] Figure 5 For the present invention Figure 4 Schematic diagram of the explosive connection structure between the middle arc arm and the supporting placement arm;

[0024] Figure 6 For the present invention Figure 5 Schematic diagram of the structure of the middle limit claw;

[0025] Figure 7 For the present invention Figure 5Schematic diagram of the explosive connection structure between the air cushion and the supporting arm;

[0026] Figure 8 For the present invention Figure 7 A schematic diagram of the cross-sectional structure of the middle air cylinder;

[0027] Fig. 9 For the present invention Figure 6 Schematic diagram of the exploded structure of the connection between the middle support boss and the arc arm.

[0028] In the figure: 1. supporting and placing arm; 11. arc-shaped flow groove; 2. arc-shaped arm; 21. supporting boss; 22. connecting arm; 221. threaded groove; 222. locking screw; 23. limiting claw; 231. arc-shaped pre-tightening groove; 232. magnetic sheet; 233. arc-shaped iron block; 24. annular locking cavity; 25. air cushion; 26. first rotating groove; 27. first connecting shaft; 28. cam; 29. ​​air guide tube; 210. air cylinder; 211. compression block; 212. return spring; 213. toggle rod; 214. semicircular toggle block; 3. T-shaped mounting plate; 31. mounting ring; 4. second rotating groove; 41. second connecting shaft; 42. circular cavity; 43. connecting rope; 44. impact ball; 45. arc-shaped metal sheet; 46. opening groove. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments so that those skilled in the art can implement the invention with reference to the description.

[0030] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0031] In the description of the present invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. to indicate directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0032] Example 1: Reference Figure 1-Figure 5A PP flexible field environmentally friendly optical cable protection device includes a supporting arm 1 that fits the surface of the optical cable. The supporting arm 1 is provided with a limiter suspended on the external steel strand. The limiter includes a pair of arc arms 2. One side of the arc arm 2 is rotatably set on the supporting arm 1, and the other side is fixedly connected to a connecting arm 22. The connecting arm 22 is fixedly connected with a limit claw 23. When the two arc arms 2 rotate around the supporting arm 1 to a locked position, the limit claws 23 at their ends overlap with each other to form an annular lock cavity 24 that matches the outer diameter of the steel strand.

[0033] In the above technical solution, in order to make the supporting arm 1 firmly fit the surface of the optical cable, the base surface of the supporting arm 1 in contact with the optical cable is designed to be an arc structure. At the same time, in order to realize the rotation of the arc arm 2 on the supporting arm 1, a pair of first rotating grooves 26 are provided on the supporting arm 1, and a first connecting shaft 27 is rotatably provided between the inner walls of the first rotating grooves 26. One side of the arc arm 2 is fixedly connected to the first connecting shaft 27. Before hanging the optical cable, the arc arm 2 is in an open state because it is located on both sides of the supporting arm 1. Figure 3 As shown, this enables the support arm 1 to be directly attached to the surface of the optical cable. Subsequently, the two arc-shaped arms 2 rotate near the center of the support arm 1 through the first connecting shaft 27 until the two limit claws 23 are closed to form an annular locking cavity 24, as shown in FIG. Figure 4 As shown, this design allows the steel strand to be clamped at 360 degrees by the annular locking cavity 24, which can effectively avoid deformation and falling off compared to the traditional method of using metal wires or hooks.

[0034] Further, refer to Figure 3-Figure 6 When the two limiting claws 23 are closed, in order to ensure the stability of clamping the steel strands, the two connecting arms 22 are vertical after overlapping, and a thread groove 221 is opened on the connecting arm 22. The inner wall of the thread groove 221 is threadedly connected with a locking screw 222. By rotating the locking screw 222, the locking screw 222 is threadedly advanced between the overlapping and connected thread grooves 221 of the two connecting arms 22, thereby ensuring that the two limiting claws 23 can tightly clamp the external steel strands. This design effectively improves the stability of the optical cable suspension.

[0035] Further, refer to Figure 6One of the limiting claws 23 is provided with an arc-shaped pre-tightening groove 231, and a matching magnetic piece 232 is fixedly connected to the arc-shaped pre-tightening groove 231, while the other limiting claw 23 is fixedly connected with an arc-shaped iron block 233 that is attracted to the magnetic piece 232. The design of the arc-shaped pre-tightening groove 231 enables the magnetic piece 232 and the arc-shaped iron block 233 to form a certain pre-tightening force when closed, which not only helps the two limiting claws 23 to fit closely, but also avoids the problem of inefficiency caused by looseness or misalignment when the locking screw 222 and the threaded groove 221 are locked. At the same time, the dual effects of magnetic attraction and pre-tightening force make the limiting claw 23 more stable after closing, which can effectively prevent the steel strand from falling off due to external force or vibration, thereby improving the safety and reliability of the overall structure.

[0036] Example 2: Reference Figure 2 On the basis of the above-mentioned embodiment 1, considering that the optical cable is in contact with the base surface of the supporting and placing arm 1, shaking will cause friction between the optical cable and the base surface, which may cause wear of the outer skin of the optical cable and even damage the internal optical fiber in the long run, affecting signal transmission. In addition, on rainy days, moisture may also penetrate into the contact surface and stay for a long time, causing aging of the outer skin of the optical cable and even corrosion of metal parts, further affecting the performance of the optical cable. Based on the problems caused by the contact between the optical cable and the base surface of the supporting and placing arm 1, this embodiment is provided with a supporting boss 21 on the arc-shaped arm 2. When the two arc-shaped arms 2 rotate around the supporting and placing arm 1 to the locking position, an air cushion 25 built into the supporting and placing arm 1 is also linked to trigger the air cushion 25 to inflate and then contact the supporting boss 2 1 forms a triangular support, which can not only stably clamp the optical cable, but also lift the optical cable away from the base surface of the support arm 1 to form a non-contact suspended state. This design makes the optical cable no longer directly contact the base surface of the support arm 1, but stably clamped between the air cushion 25 and the two supporting bosses 21. On the one hand, it effectively prevents friction and wear caused by shaking, and protects the outer skin of the optical cable and the internal optical fiber. On the other hand, the optical cable is out of contact with the base surface, which reduces the possibility of rainwater infiltration and retention, thereby reducing the risk of aging of the outer skin of the optical cable and corrosion of metal parts. Through the suspension support design of the optical cable, this embodiment effectively solves the problem of performance degradation of the optical cable due to contact friction and water retention, and has high practicality and reliability.

[0037] It should be noted that although the optical cable is clamped between the air cushion 25 and the two supporting bosses 21, there is still a certain contact, but this contact is much less than the direct contact with the base surface of the support placement arm 1, because the contact between the air cushion 25 and the supporting boss 21 and the optical cable is local and limited, much smaller than the large-area contact between the optical cable and the base surface of the support placement arm 1, thereby further reducing the possibility of friction and wear. Moreover, the air cushion 25 has a certain elasticity and can absorb the impact force generated by shaking, reduce the direct pressure on the optical cable, and further reduce the risk of wear. In addition, the triangular support structure also provides a more uniform force distribution, so that the optical cable can remain stable when shaking, avoiding direct friction with the base surface of the support placement arm 1.

[0038] Therefore, although there is contact between the optical cable and the air cushion 25 and the supporting boss 21, this design greatly reduces the contact area and friction, and at the same time avoids direct contact between the optical cable and the base surface of the supporting arm 1 through the suspended state, thereby effectively solving the problems of friction wear and moisture retention, and improving the durability and reliability of the optical cable.

[0039] In order to implement the above technical solution, refer to Figure 2-Figure 8 A pair of cams 28 are fixedly connected to the first connecting shaft 27, and the surface of the cam 28 is linked to an air deflector assembly connected to the air cushion 25. The air deflector assembly includes an air guide pipe 29, one end of the air guide pipe 29 is connected to the air inlet head on the air cushion 25, and the other end of the air guide pipe 29 is connected to an air deflector 210. A pair of T-shaped mounting plates 3 are fixedly connected to the supporting arm 1, and a mounting ring 31 is fixedly connected between the T-shaped mounting plate 3 and the surface of the air deflector 210. A matching compression block 211 is fitted on the inner wall of the air deflector 210, and a return spring 212 is fixedly connected between the bottom of the compression block 211 and the bottom wall of the air deflector 210. A toggle rod 213 is fixedly connected to the top of the compression block 211, and one end of the toggle rod 213 extending to the top of the air deflector 210 is fixedly connected to a semicircular toggle block 214 fitted with the surface of the cam 28.

[0040] During use, when the arc-shaped arms 2 unfolded at both sides of the supporting arm 1 rotate through the first connecting shaft 27 until the two limit claws 23 are closed, the two cams 28 fixed on the first connecting shaft 27 will change from the initial horizontal state to the vertical state, such as Figure 3 and Figure 4As shown, at this time, the semicircular toggle block 214, under the rotation and extrusion of the cam 28, will drive the toggle rod 213 to push the compression block 211 to slide along the inner wall of the air cylinder 210, and squeeze the return spring 212, so that the compressed gas in the air cylinder 210 enters the air cushion 25 through the air guide tube 29, and the air cushion 25 is inflated. The inflated air cushion 25 expands and lifts the optical cable originally attached to the base surface of the supporting arm 1, so that it is stably clamped between the air cushion 25 and the two supporting bosses 21, forming a stable clamping area. At the same time, the optical cable leaves the base surface of the supporting arm 1, forming a non-contact suspended state. This design effectively solves the problem of performance degradation of the optical cable due to friction, wear and moisture retention, and improves the durability and reliability of the optical cable.

[0041] Further, refer to Figure 4 The air cushion 25 is located at the center of the base surface of the supporting arm 1. When the air cushion 25 is inflated, it lifts the optical cable and makes the optical cable leave the base surface of the supporting arm 1 to form a non-contact suspended state. By connecting the supporting arm 1 with evenly distributed arc flow grooves 11, on the one hand, the flow space at the base surface of the supporting arm 1 can be increased, avoiding direct contact between the optical cable and the base surface. In hot weather, this design can effectively dissipate heat and prevent the optical cable from being damaged due to overheating. On rainy days, moisture dripping to the base surface of the supporting arm 1 can be quickly discharged through the arc flow groove 11, thereby improving the dryness of the base surface and reducing the influence of moisture retention on the optical cable. Through this design, not only the overheating problem of the optical cable caused by direct contact is solved, but also the drainage performance of the supporting arm 1 is improved, further enhancing the durability and reliability of the optical cable.

[0042] Example 3: Reference Figure 6 and Fig. 9 Considering that if the circular support boss 21 is fixedly connected to the arc-shaped arm 2, when the optical cable is shaken by wind, the fixed support boss 21 may increase the friction of the optical cable, thereby causing wear problems, this example is based on the above-mentioned embodiment 2, but is different in that when the support boss 21 and the arc-shaped arm 2 are rotatably arranged, it includes a second rotation groove 4 opened on the arc-shaped arm 2, and a second connecting shaft 41 is fixedly connected between the inner walls of the second rotation groove 4. The support boss 21 is rotatably connected to the second connecting shaft 41. When the optical cable is shaken by wind or other external forces, the support boss 21 can rotate with the shaking of the optical cable, thereby reducing the rigid friction between the optical cable and the support boss 21. This rotation design enables the support boss 21 to adapt to the movement of the optical cable and avoid the problem of increased friction caused by the fixed connection.

[0043] Furthermore, refer to Fig. 9A circular cavity 42 is provided inside the supporting boss 21, a connecting rope 43 corresponding to the inside of the circular cavity 42 is fixedly connected to the second connecting shaft 41, an impact ball 44 is fixedly connected to the end of the connecting rope 43, a plurality of arc-shaped metal sheets 45 distributed in a circle are fixedly connected to the inner wall of the circular cavity 42, and an opening groove 46 corresponding to the arc-shaped metal sheet 45 is connected to the surface of the supporting boss 21. When the supporting boss 21 rotates with the shaking of the optical cable or rotates due to the contact of a bird with the supporting boss 21, the arc-shaped metal sheet 45 on the inner wall of the circular cavity 42 will collide with the impact ball 44, thereby making a sound, and then the sound is transmitted through the opening groove 46 on the surface of the supporting boss 21, which serves as a warning or bird-repelling effect, thereby preventing birds from damaging the optical cable or the supporting structure.

[0044] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the present invention can make some changes or modify the technical contents suggested above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the solution of the present invention.

Claims

1. A PP flexible field environmentally friendly optical cable protection device, comprising: A supporting arm (1) is provided which is in contact with the surface of the optical cable, and a limiting member suspended on the external steel strand is provided on the supporting arm (1); the characteristics are: The limiting member comprises a pair of arc-shaped arms (2), wherein a supporting boss (21) is arranged on the arc-shaped arms (2), one side of the arc-shaped arms (2) is rotatably arranged on the supporting placement arm (1), and the other side of the arc-shaped arms (2) is fixedly connected to a connecting arm (22), and a limiting claw (23) is fixedly connected to the connecting arm (22); When the two arc-shaped arms (2) rotate around the supporting arm (1) to a locked position, the limiting claws (23) at their ends overlap with each other to form an annular locking cavity (24) matching the outer diameter of the steel strand. At the same time, an air cushion (25) built into the supporting arm (1) is linked to trigger the air cushion (25) to be inflated to form a triangular support with the supporting boss (21), thereby lifting the optical cable away from the base surface of the supporting arm (1) to form a non-contact suspended state.

2. A PP flexible field environmentally friendly optical cable protection device according to claim 1, characterized in that: The base surface of the supporting and placing arm (1) in contact with the optical cable is an arc-shaped structure. The supporting and placing arm (1) is provided with a pair of first rotating grooves (26). A first connecting shaft (27) is rotatably arranged between the inner walls of the first rotating grooves (26). One side of the arc-shaped arm (2) is fixedly connected to the first connecting shaft (27).

3. A PP flexible field environment-friendly optical cable protection device according to claim 2, characterized in that: The two connecting arms (22) are in a vertical shape after being overlapped, and a thread groove (221) is provided on the connecting arm (22), and a locking screw rod (222) is threadedly connected to the inner wall of the thread groove (221).

4. A PP flexible field environment-friendly optical cable protection device according to claim 3, characterized in that: One of the limiting claws (23) is provided with an arc-shaped pre-tightening groove (231), to which a matching magnetic sheet (232) is fixedly connected, while the other limiting claw (23) is fixedly connected with an arc-shaped iron block (233) attracted to the magnetic sheet (232).

5. A PP flexible field environment-friendly optical cable protection device according to claim 2, characterized in that: A pair of cams (28) are fixedly connected to the first connecting shaft (27), and the surfaces of the cams (28) are linked with an air-displacing assembly that is in communication with the air cushion (25).

6. A PP flexible field environment-friendly optical cable protection device according to claim 5, characterized in that: The air deflector assembly comprises an air guide pipe (29), one end of the air guide pipe (29) is connected to an air inlet head on an air cushion (25), the other end of the air guide pipe (29) is connected to an air deflector cylinder (210), an inner wall of the air deflector cylinder (210) is fitted with a matching compression block (211), a return spring (212) is fixedly connected between the bottom of the compression block (211) and the bottom wall of the air deflector cylinder (210), a toggle rod (213) is fixedly connected to the top of the compression block (211), and one end of the toggle rod (213) extending to the top of the air deflector cylinder (210) is fixedly connected to a semicircular toggle block (214) fitted with the surface of the cam (28).

7. A PP flexible field environment-friendly optical cable protection device according to claim 6, characterized in that: The air cushion (25) is located at the center of the base surface of the supporting and placing arm (1), and the supporting and placing arm (1) is connected to evenly distributed arc-shaped flow grooves (11).

8. A PP flexible field environment-friendly optical cable protection device according to claim 6, characterized in that: A pair of T-shaped mounting plates (3) are fixedly connected to the supporting placement arm (1), and a mounting ring (31) is fixedly connected between the T-shaped mounting plate (3) and the surface of the air cylinder (210).

9. A PP flexible field environment-friendly optical cable protection device according to claim 6, characterized in that: When the support boss (21) and the arc-shaped arm (2) are rotatably arranged, they include a second rotation groove (4) provided on the arc-shaped arm (2), a second connecting shaft (41) is fixedly connected between the inner walls of the second rotation groove (4), and the support boss (21) is rotatably connected to the second connecting shaft (41).

10. A PP flexible field environment-friendly optical cable protection device according to claim 9, characterized in that: A circular cavity (42) is provided inside the supporting boss (21); a connecting rope (43) corresponding to the inside of the circular cavity (42) is fixedly connected to the second connecting shaft (41); an impact ball (44) is fixedly connected to the end of the connecting rope (43); a plurality of arc-shaped metal sheets (45) distributed in a circumference are fixedly connected to the inner wall of the circular cavity (42); and an open groove (46) corresponding to the arc-shaped metal sheet (45) is connected to the surface of the supporting boss (21).

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