Protection cable and lock with protection cable
By incorporating two protective layers and a design that restricts the movement of the locking mechanism on the chain lock, the problems of corrosion and jamming in chain locks are solved. This achieves the effects of preventing violent damage and ensuring the key returns to its normal position, thereby improving the durability of the lock and the user experience.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WENZHOU TONGYONG LOCKS CO LTD
- Filing Date
- 2026-02-03
- Publication Date
- 2026-05-12
AI Technical Summary
Existing chain locks or cable locks are easily corroded and damaged by force, and the friction between the locking head and the inner wall of the lock body can cause jamming, preventing the key from returning to its original position.
The protective cable features a double-layer design, with an inner core made of a chain of metal or composite material and an outer layer of fiber or metal wire braid. It also includes a limiting device and bevel design to restrict the movement of the locking head and prevent jamming. The improved shell assembly connection method facilitates maintenance.
It effectively prevents violent damage, reduces friction and jamming, ensures the key returns to its normal position, and improves service life and user experience.
Smart Images
Figure CN122014055A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of lock technology, specifically a safety rope and a lock equipped with the safety rope. Background Technology
[0002] In commercially available chain locks or cable locks, the chain and cable are exposed, making them susceptible to corrosion and damage from force. Therefore, a protective cable is needed to safeguard the chain or cable. Furthermore, on November 25, 2025, the applicant applied for patent number 2025224991921, entitled "A Simple and Easy-to-Lock Lock." In this lock, the locking head lacks a limiting structure to restrict the insertion direction of the moving head. When rotating, the locking head moves towards the moving head, causing friction and even jamming between the locking head and the inner wall of the lock body, preventing it from returning to its original position. Additionally, the inner wall of the locking head contacts the rotating part through the plane of the inner wall of the locking head against the outer edge of the rotating part. During use, we found that when turning the key, the widest part of the rotating part easily pushes against the locking head, causing jamming and preventing the key from returning to its original position, thus preventing the locking head from locking. Summary of the Invention
[0003] To address the technical problems mentioned in the background section, the present invention mainly provides a protective cable with a protective chain or steel cable.
[0004] To achieve the above objectives, the present invention provides the following technical solution:
[0005] A protective cord includes an inner core and a wrapping material disposed outside the inner core. The wrapping material consists of two protective layers made of two different materials. Each protective layer is a woven fabric, braided fabric, or laid fabric made of fibers, yarns, or metal wires, and the woven fabrics of the two protective layers are arranged overlapping each other.
[0006] Preferably, the fibers or yarns used to construct woven fabrics, braided fabrics and / or spread fabrics are selected from: chemical fibers and / or natural fibers or yarns composed of chemical fibers and / or natural fibers.
[0007] Preferably, the inner core is a chain, which is made of metal or composite material, and the chain is a lock chain with a thickness of any value between 3mm and 9mm. The chain is surrounded by composite filaments, yarns, or twisted threads.
[0008] Preferably, the chemical fiber is made of synthetic polymers, polyester fibers, inorganic materials, and metal fibers; the inorganic materials include carbon fiber, glass fiber, boron fiber, quartz fiber, nanotube fiber, ceramic fiber, basalt fiber, and slag fiber.
[0009] Preferably, the fibers made from synthetic polymers are selected from fibers made from the following materials: ultra-high molecular weight polyethylene, polyethylene terephthalate, polyethylene terephthalate, and polybutylene terephthalate; polypropylene, polyamide, trivinyl, polyimide, elastic polypolyester, polybenzimidazole, polyphenylene sulfide, polyurea, vinyl, polyamide-imide, polychloride, aramid, elastic polyolefin, polyacrylate, polytetrafluoroethylene, polyethylene, polybenzoxazole, polystyrene, and polycarbonate; the fibers made from natural polymers are selected from: fibers made from regenerated cellulose; fibers made from cellulose esters; protein fibers; polylactic acid fibers, bio-based polyamide fibers, and elastic diene fibers.
[0010] Preferably, the woven fabric, braided fabric, and / or laid fabric comprises a mixture or combination of the fibers or yarns.
[0011] Preferably, the metal wires used to construct woven, braided, and / or laid fabrics comprise metal wires, metal foils, or a metallic coating on textile fibers.
[0012] A lock with the aforementioned protective cable includes a lock body and a movable head. The lock body includes a shell assembly and a lock cylinder. The protective cable has a fixed head and a movable head at both ends. The fixed head of the protective cable is fixed to the shell assembly of the lock body, and the movable head of the protective cable can be movably inserted into the lock body. The movable head has a lock groove. The lock body also includes a mounting base, on which at least one latch is movably provided. The latch has a locking part that can be engaged in the lock groove in the locked state. The output end of the lock cylinder is drivenly connected to a rotating component. When the rotating component rotates, it directly pushes the latch to disengage the locking part of the latch from the lock groove of the movable head to unlock. A limiting device is provided between the latch and the mounting base to restrict the movement of the latch towards the movable head.
[0013] Preferably, the limiting device includes outwardly extending locking pins on both sides of the locking head, and a groove for the locking pins of the locking head to be engaged at a corresponding position on the mounting base, the inner wall of the groove restricting the locking pins from moving towards the movable head side.
[0014] Preferably, the contact surface between the clamp head and the rotating component is provided with a first guide slope. When the rotating component rotates to its widest position and abuts against the clamp head, the rotating component abuts against the first guide slope of the clamp head.
[0015] Preferably, the lock body includes an outer shell, an outer sleeve, an inner shell, and a core sleeve that are sequentially fitted from the outside to the inside. The core sleeve is fitted over the lock cylinder, and the outer surface of the core sleeve is provided with a locking hole for the end of the fixing head to be inserted. The inner shell is provided with a locking part to lock the fixing head. The inner shell and the core sleeve are restricted to axial movement of the inner shell by a radial pin. An axial pin is provided between the inner shell and the mounting base. A portion of the axial pin is inserted into the inner shell, and a portion of the axial pin is located in the mounting base. A set screw is threaded onto the mounting base or outer sleeve at the tail of the axial pin.
[0016] The beneficial effects of this invention are as follows: The protective cable of this invention, by setting two protective layers on the outside of the chain, can effectively prevent violent damage, such as sawing or cutting with the aid of cable cutters, cutting machines or diamond tools; cutting with the aid of sharp blades; tearing; or through the action of heat (e.g., with the aid of fire, gas burners, etc.) or the action of cold, with the aid of refrigerants (e.g., liquid helium, liquid nitrogen or liquid oxygen) to achieve strong local supercooling, which causes conventional materials, such as steel, to become brittle and can be destroyed by hammering. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention;
[0018] Figure 2 This is a cross-sectional view of the present invention;
[0019] Figure 3 This is a schematic diagram of the rotating component of the present invention;
[0020] Figure 4 This is a schematic diagram of the structure of the card head of the present invention;
[0021] Figure 5 This is a structural schematic diagram of the card head of the present invention from another perspective;
[0022] Figure 6 This is a schematic diagram of the structure of the elastic element of the present invention;
[0023] Figure 7 This is a schematic diagram of the connection structure between the mounting base and the clip head of the present invention;
[0024] Figure 8 This is a schematic diagram of the mounting base of the present invention;
[0025] Figure 9 This is a schematic diagram of the structure of the first torsion spring of the present invention;
[0026] Figure 10 This is a schematic diagram of the structure of the present invention with the outer shell and outer cover removed;
[0027] Figure 11 This is a schematic diagram of the inner shell structure of the present invention;
[0028] Figure 12 This is a schematic diagram of the structure of the protective cable of the present invention.
[0029] Explanation of reference numerals in the attached drawings: 1. Lock body; 2. Shell assembly; 201. Outer shell; 202. Outer sleeve; 203. Inner shell; 2031. Snap-fit part; 204. Core sleeve; 2041. Snap hole; 205. Radial pin; 206. Axial pin; 207. Set screw; 3. Lock cylinder; 301. Transmission part; 4. Mounting base; 401. Snap groove; 402. Mounting through groove; 403. Mounting space; 404. Slot; 40 5. Crossbar; 406. Groove; 5. Clip head; 501. Snap-fit part; 502. Mounting groove; 503. Second guide slope; 504. Column; 505. Lower protruding rib; 506. Clip post; 507. First guide slope; 6. Rotating component; 7. First torsion spring; 8. Elastic component; 9. Protective cable; 901. Inner core; 902. Wrapping material; 903. Fixed head; 904. Movable head; 9041. Locking groove. Detailed Implementation
[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0031] Example
[0032] Please see Figures 1-12The figure shows a lock, which includes a lock body 1 and a protective cable. The lock body 1 includes a shell assembly 2 and a lock cylinder 3. The protective cable 9 has a fixed head 903 and a movable head 904 at both ends. The fixed head 903 of the protective cable is fixed to the shell assembly of the lock body, and the movable head 904 of the protective cable can be movably inserted into the lock body 1. It is worth noting that the protective cable 9 includes an inner core 901 and a covering 902 located outside the inner core 901. The covering 902 consists of two protective layers made of two different materials. Each protective layer is a woven, braided, or laid fabric made of fiber, yarn, or metal wire, and the woven or braided fabrics of the two protective layers are arranged overlapping each other. In this embodiment, the inner core is a chain, which is made of metal or composite material. The chain is a lock chain, and the chain thickness is any value between 3mm and 9mm. In this embodiment, the movable head 904 has a locking groove 9041, and the lock body 1 also includes a mounting base 4. At least one latch 5 is movably mounted on the mounting base 4. The latch 5 has a latching part 501 that can be engaged in the locking groove 9041 in the locked state. The output end of the lock cylinder 3 is drivenly connected to a rotating member 6. When the rotating member 6 rotates, it directly pushes the latch 5 to disengage the latching part 501 of the latch 5 from the locking groove 9041 of the movable head 904 to unlock. It is further worth noting in this embodiment that a limiting device is provided between the latch 5 and the mounting base 4 to restrict the movement of the latch 5 towards the movable head 904. The limiting device includes latching posts 506 extending outward on both sides of the latch 5, and a groove 406 at a corresponding position on the mounting base 4 for the latching posts 506 of the latch 5 to be engaged. The inner wall of the groove 406 restricts the movement of the latching posts 506 towards the movable head 904. The groove and locking pin limit the range of motion of the locking head, thereby preventing the locking head from getting stuck due to friction with the lock body's housing components during rotation, and ensuring that the key can return to its normal position.
[0033] A further noteworthy feature of this embodiment is that the contact surface between the locking head 5 and the rotating member 6 is provided with a first guide slope 507. When the rotating member 6 rotates to its widest position and abuts against the locking head 5, the rotating member 6 abuts against the first guide slope 507 of the locking head 5. The sloped design of the contact surface between the locking head 5 and the rotating member 6 ensures that the rotating member will not cause jamming when it abuts against the locking head at its widest position, further ensuring that the key can return to its normal position and improving the user experience.
[0034] In this embodiment, it is further noteworthy that the shell assembly 2 includes an outer shell 201, an outer sleeve 202, an inner shell 203, and a core sleeve 204, which are sequentially sleeved from the outside to the inside. The core sleeve 204 is sleeved on the outside of the lock cylinder 3. The outer surface of the core sleeve 204 is provided with a locking hole 2041 for inserting the end of the fixing head 903. The inner shell 203 is provided with a latching part 2031 for locking the movable head. The inner shell 203 and the core sleeve 204 are restricted to axial movement of the inner shell 203 by a radial pin 205. An axial pin 206 is provided between the inner shell 203 and the mounting base 4. A portion of the axial pin 206 is inserted into the inner shell 203, and a portion of the axial pin 206 is located in the mounting base 4. A set screw 207 is threadedly connected to the mounting base 4 or the outer sleeve 202 at the tail of the axial pin 206. This technology addresses the issue of existing systems where the outer and inner shells are directly fixed by a pin, making subsequent disassembly and maintenance impossible. In this embodiment, the outer and inner shells are connected by an axial pin, and a detachable set screw is provided at the end of the axial pin. When disassembly is required, the set screw can be removed and the axial pin pulled out to disassemble the entire shell assembly for internal maintenance. The set screw can be covered by the movable head of the protective cable after it is engaged, preventing it from being removed by others.
[0035] In this embodiment, the fibers or yarns used to construct the woven, braided, and / or laid fabrics are selected from: chemical fibers and / or natural fibers, or yarns composed of chemical fibers and / or natural fibers. The inner core 901 is a chain, which is made of metal or composite materials. The chain is a lock chain, and the chain thickness is any value between 3mm and 9mm. The chain is surrounded by composite filaments, yarns, or twisted yarns. The chemical fibers are fibers made of synthetic polymers, polyester fibers, fibers made of inorganic materials, and metal fibers; the inorganic fibers are carbon fibers, glass fibers, boron fibers, quartz fibers, nanotube fibers, ceramic fibers, basalt fibers, and slag fibers. The fibers made from synthetic polymers are selected from fibers made from the following materials: ultra-high molecular weight polyethylene, polyethylene terephthalate, polyethylene terephthalate, and polybutylene terephthalate; polypropylene, polyamide, trivinyl, polyimide, elastic polypolyester, polybenzimidazole, polyphenylene sulfide, polyurea, vinyl, polyamide-imide, polychloride, aramid, elastic polyolefin, polyacrylate, polytetrafluoroethylene, polyethylene, polybenzoxazole, polystyrene, and polycarbonate; the fibers made from natural polymers are selected from: fibers made from regenerated cellulose; fibers made from cellulose esters; protein fibers; polylactic acid fibers, bio-based polyamide fibers, and elastic diene fibers. The woven fabrics, braided fabrics, and / or laid fabrics comprise a mixture or combination of the fibers or yarns. The metal wires used to construct the woven fabrics, braided fabrics, and / or laid fabrics comprise metal wires, metal foils, or a metallic coating on textile fibers. The outer covering 902 of the protective cable not only provides good protection for the inner core, but also reduces impact and provides multiple protections in the event of violent damage. For example, without the covering, the inner core can be forcibly cut, causing the protective cable to break. However, with the addition of the covering in this application, the covering has extremely strong toughness, preventing it from being cut.
[0036] In this embodiment, there are two symmetrically arranged locking heads. Each locking head 5 has a locking portion 501 that can engage with the lock groove 9041 in the locked state. A rotating member 6 is connected to the output end of the lock cylinder 3. When the rotating member 6 rotates, it directly pushes the locking head 5, causing the locking portion 501 of the locking head 5 to disengage from the lock groove 9041 of the movable head 904, thus unlocking the lock. In this embodiment, the mounting base 4 has a hollow structure in the middle, and the rotating member 6 rotates freely within this hollow portion. The rotation of the rotating member 6 is achieved by turning the lock cylinder 3 with a key. Specifically, the transmission between the two is achieved by a non-circular transmission part 301 at the end of the lock cylinder 3, and the rotating member 6 is directly fitted onto this transmission part 301. The two locking heads 5 are located on the mounting base 4 on both sides of the rotating member 6. When the rotating member 6 rotates, the outer wall of the rotating member 6 pushes open the locking heads 5, causing the two locking heads 5 to open. This allows the locking parts 501 of the two locking heads 5 to disengage from the locking groove 9041, at which point the movable head 904 can be freely pulled out. In order to enable the lock cylinder 3 to automatically reset, a first torsion spring 7 is provided between the rotating part 6 and the mounting base 4. One end of the first torsion spring 7 is inserted into the rotating part 6, and the rotating part 6 has a hole for inserting one end of the first torsion spring 7. The other end of the first torsion spring 7 is locked onto the mounting base 4, and the mounting base 4 has a slot 401 for the end of the first torsion spring 7 to be locked into. In order to facilitate the end of the first torsion spring 7 to be easily locked into the slot 401 of the mounting base 4, this embodiment provides a mounting through groove 402 at the slot 401 of the mounting base 4. The mounting through groove 402 makes the space for the mounting base 4 to install the first torsion spring 7 communicate with the outside of the mounting base 4, thereby facilitating the installation of the first torsion spring 7.
[0037] To enable the locking head 5 to quickly reset, this embodiment also includes an elastic element 8 that elastically drives the locking head 5 into a locked state. In this embodiment, the elastic element 8 is a second torsion spring. One end of the second torsion spring abuts against the locking head 5, and the other end abuts against the inner wall of the lock body 1. A mounting space 403 is provided on the mounting base 4 for the main body of the second torsion spring to be inserted. In this embodiment, the elastic element 8 for resetting the locking head 5 is designed as a second torsion spring at its rear. By providing a mounting groove 502 at its rear to fix the second torsion spring, it can be firmly fixed, preventing displacement. Traditional straight-tube springs are prone to deformation in the extended state and may detach from the mounting position. The second torsion spring in this embodiment completely avoids this situation, thereby further ensuring the product's service life.
[0038] In this embodiment, in order to enable the rotating member 6 to intermittently drive the locking head 5, the rotating member 6 has a narrow region and a wide region. When the rotating member 6 rotates to the wide region facing the locking head 5, the rotating member 6 pushes the locking head 5, causing the locking head 5 to rotate, and the locking part 501 of the locking head 5 disengages from the locking groove 9041 and unlocks. When the rotating member 6 rotates to the narrow region, the locking head 5 returns to its original position under the action of the second torsion spring and is in a locked state. The rotating component 6 has an elliptical or racetrack-shaped cross-section. In this embodiment, an elliptical structure is adopted. When the two ends of the elliptical rotating component 6 in the major axis direction abut against the locking head 5, the displacement of the rotating end of the locking head 5 is limited by the mounting base 4 and the lock body 1, so it can only rotate. Therefore, when pushed by the rotating component 6, one end of the locking part 501 of the locking head 5 will move away from the locking groove 9041 of the movable head 904, thus unlocking. When the two ends of the elliptical rotating component 6 in the minor axis direction abut against the locking head 5, the displacement of the rotating end of the locking head 5 is also limited, and the rotating component 6 is reset by the action of the second torsion spring. In this embodiment, in order to prevent the rotating component 6 from disengaging from the lock cylinder 3.
[0039] In order to achieve keyless locking, this embodiment provides a second guide slope 503 at the end of the card head 5 facing the movable head 904. When the movable head 904 is inserted, the movable head 904 pushes open the card head 5 through the second guide slope 503. In order to further facilitate the insertion of the movable head 904, the end side of the movable head 904 is tapered, making it easier to push open the card head 5.
[0040] In this embodiment, the mounting base 4 and the core sleeve of the lock cylinder 3 are an integral structure. This design enables the lock to be assembled quickly and saves costs. The integral structure of the two does not require a separate mounting base 4 for fixing, and the strength is also improved.
[0041] In order to allow the locking head 5 and the mounting base 4 to rotate more smoothly and reduce jamming, this embodiment has a smooth column 504 at the rotational engagement position of the locking head 5 and the mounting base 4, and the corresponding mounting base 4 has a smooth arc surface. Since the rotating parts are all smooth structures, even if dust enters between the locking head 5 and the mounting base 4, it is difficult to cause a large blockage, thereby further reducing the force required to turn the key, and no jamming will occur even after long-term use, resulting in a longer service life.
[0042] In this embodiment, in order for the clasp 5 to rotate, a slot 404 for the clasp 5 to rotate is provided on the mounting base 4. In order to prevent it from rotating excessively and causing the movable head 904 to be unable to push open the clasp 5, a crossbar 405 is provided at the slot 404 to limit the excessive extension of the clasp 5. The crossbar 405 can limit the two clasp 5 to have a suitable opening in the locked state, so that the clasp 5 can be easily pushed open by the movable head 904.
[0043] In order for the locking head 5 to more firmly lock the movable head 904, this embodiment provides a downwardly protruding rib 505 on the surface of the locking part 501 of the locking head that contacts the movable head, or the contact surface is designed as a hook-shaped structure with the end tilted downward. The corresponding locking groove 9041 of the movable head 904 and the surface of the lower rib 505 that engages are concave on the inside and upturned on the outside of a tapered surface 202. In this way, the lower rib of the locking head can firmly lock the locking groove of the movable head, making it difficult to pull out after the movable head is inserted and locked.
Claims
1. A protective cable, characterized in that: It includes an inner core (901) and a wrapping material (902) disposed outside the inner core (901). The wrapping material (902) consists of two protective layers made of two materials. Each protective layer is a woven fabric, braided fabric or laid fabric made of fiber, yarn or metal wire. The woven fabric or braided fabric of the two protective layers is arranged on top of each other.
2. The protective cable as described in claim 1, characterized in that: The fibers or yarns used to construct woven, braided and / or laid fabrics are selected from: chemical fibers and / or natural fibers or yarns composed of chemical fibers and / or natural fibers.
3. The protective cable as described in claim 1, characterized in that: The inner core (901) is a chain, which is made of metal or composite material. The chain is a lock chain, and the chain thickness is any value between 3mm and 9mm. The chain is surrounded by composite filaments, yarns, or twisted threads.
4. The protective cable as described in claim 2, characterized in that: The chemical fibers are made of synthetic polymers, polyester fibers, inorganic fibers, and metal fibers; the inorganic fibers are carbon fibers, glass fibers, boron fibers, quartz fibers, nanotube fibers, ceramic fibers, basalt fibers, and slag fibers.
5. The protective cable as described in claim 4, characterized in that: The fibers made from synthetic polymers are selected from fibers made from the following materials: ultra-high molecular weight polyethylene, polyethylene terephthalate, polyethylene terephthalate, and polybutylene terephthalate; polypropylene, polyamide, trivinyl, polyimide, elastic polypolyester, polybenzimidazole, polyphenylene sulfide, polyurea, vinyl, polyamide-imide, polychloride, aramid, elastic polyolefin, polyacrylate, polytetrafluoroethylene, polyethylene, polybenzoxazole, polystyrene, and polycarbonate; the fibers made from natural polymers are selected from: fibers made from regenerated cellulose; fibers made from cellulose esters; protein fibers; polylactic acid fibers, bio-based polyamide fibers, and elastic diene fibers.
6. The protective cable as described in claim 2, characterized in that: The woven fabric, braided fabric, and / or laid fabric comprises a mixture or combination of the fibers or yarns.
7. The protective cable as described in claim 6, characterized in that: Metal wires used to construct woven, braided, and / or laid fabrics include metal wires, metal foils, or metal coatings on textile fibers.
8. A lock with a protective cable as described in any one of claims 1-7, comprising a lock body (1) and a movable head (904). The lock body (1) includes a housing assembly (2) and a lock cylinder (3). The protective cable (9) has a fixed head (903) and a movable head (904) at both ends. The fixed head (903) of the protective cable is fixed to the housing assembly (2) of the lock body (1). The movable head (904) of the protective cable is movably inserted into the lock body (1). The movable head (904) has a lock groove. (9041), the lock body (1) also includes a mounting base (4), on which at least one latch (5) is movably provided. The latch (5) has a latching part (501) that can be latched into the lock groove (9041) in the locked state. The output end of the lock cylinder (3) is connected to a rotating member (6). When the rotating member (6) rotates, it directly pushes the latch (5) to disengage the latching part (501) of the latch (5) from the lock groove (9041) of the movable head to unlock. The lock body (1) is characterized in that: A limiting device is provided between the card head (5) and the mounting base (4) to restrict the movement of the card head (5) toward the movable head (904).
9. The lock as described in claim 8, characterized in that: The limiting device includes outwardly extending locking pins (506) on both sides of the locking head (5), and a groove (406) for the locking pins (506) of the locking head (5) to be inserted into at the corresponding position of the mounting base (4). The inner wall of the groove (406) restricts the locking pins (506) from moving toward the movable head (904).
10. The lock as described in claim 8, characterized in that: The contact surface between the clamp head (5) and the rotating part (6) is provided with a first guide slope (507). When the rotating part (6) rotates to the widest position and abuts against the clamp head (5), the rotating part (6) abuts against the first guide slope (507) of the clamp head (5).
11. The lock as described in claim 8, characterized in that: The lock body (1) includes an outer shell (201), an outer sleeve (202), an inner shell (203), and a core sleeve (204) sequentially fitted from the outside to the inside. The core sleeve (204) is fitted over the lock cylinder (3). The outer surface of the core sleeve (204) is provided with a locking hole (2041) for inserting the end of the fixing head (903). The inner shell (203) is provided with a latching part (2031) for locking the fixing head (903). The inner shell (203) and the core sleeve (204) are fitted together. 2041) The axial movement of the inner shell (203) is restricted by a radial pin (205). An axial pin (206) is provided between the inner shell (203) and the mounting base (4). A portion of the axial pin (206) is inserted into the inner shell (203), and a portion of the axial pin (206) is located in the mounting base (4). A set screw (207) is threaded onto the mounting base (4) or outer sleeve (202) at the tail of the axial pin (206).