Anti-tamper fastening screw
By designing multiple anti-tamper structures on the screw, including elastic deformation interlocking of the collar and the inclined insert, the problem of poor anti-tampering effect of traditional screws is solved, achieving a highly efficient anti-tampering effect, which is suitable for high-security protection scenarios.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN ELOAM TECH CO LTD
- Filing Date
- 2025-07-04
- Publication Date
- 2026-06-09
AI Technical Summary
Existing anti-tamper screws have a simple structure and limited anti-tampering effect, which cannot meet the high security protection requirements of scenarios such as high-speed rail carriage connectors and power equipment boxes.
A tamper-proof fastening screw was designed, which consists of a first nut, a connecting rod, and a second nut at the top of the screw, and a collar with an arc-shaped metal strip fitted on the top of the screw. The bottom surface of the first nut is provided with inclined inserts. Combined with the elastic deformation of the metal strip and the mechanical interlocking structure, a multi-layered tamper-proof mechanism is formed.
It significantly improves the fastening reliability and anti-disassembly performance of screws, effectively preventing unauthorized disassembly, and is suitable for high-security protection scenarios.
Smart Images
Figure CN224339316U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of screw technology, specifically to an anti-disassembly fastening screw. Background Technology
[0002] In various fields such as industrial production, equipment installation, and 3C digital electronic products, screws are fundamental and commonly used fasteners, and their anti-tampering performance is always a key factor. Traditional fasteners mostly use a single nut structure, which allows users to easily remove them using a standard screwdriver or wrench. However, this also brings many safety hazards, such as the risk of unauthorized disassembly, which could lead to component theft or malicious damage to equipment.
[0003] Many existing tamper-proof screws achieve their tamper-proof function through the design of special screw heads. However, this design has obvious drawbacks: the structure is relatively simple, and the tamper-proof effect is very limited. When facing scenarios with high security requirements, such as high-speed rail carriage connectors, power equipment boxes, and outdoor security facilities, existing tamper-proof screws simply cannot meet the needs. Utility Model Content
[0004] The purpose of this utility model is to provide an anti-tamper fastening screw. By sequentially setting a first nut part, a connecting rod and a second nut part at the top of the screw part, and a collar with an arc-shaped metal strip on the top of the screw part, and setting inclined circumferentially distributed inserts on the bottom surface of the first nut part, this invention solves the problem that traditional anti-tamper screws have a simple structure and limited anti-tampering effect, and cannot meet the needs of high-security protection scenarios such as high-speed rail carriage connectors and power equipment boxes.
[0005] This utility model is achieved through the following technical solution:
[0006] This utility model is an anti-disassembly fastening screw, including a screw rod, a first nut part fixedly connected to the top end of the screw rod, a connecting rod fixedly connected to the top end of the first nut part, and a second nut part fixedly connected to the end of the connecting rod.
[0007] A collar is fitted on the top of the screw section, and multiple metal strips are fixedly connected to the outer surface of the collar. The metal strips are arc-shaped and their two ends are fixed to the top and bottom of the collar, respectively.
[0008] The bottom end face of the first nut is fixedly connected with a plurality of inserts, and the plurality of inserts are arranged in an inclined circumferential distribution.
[0009] Furthermore, the top surface of the second nut portion is provided with an irregularly shaped groove.
[0010] Furthermore, the outer diameter of the connecting rod is smaller than the outer diameters of the first nut portion and the second nut portion, and the middle part of the connecting rod is provided with an annular weak groove.
[0011] Furthermore, the collar and the screw portion are in clearance fit.
[0012] Furthermore, the inclination angle of the insert is 30°-60°, and the top and bottom of the metal strip can be pressed into contact with the mounting surface and the bottom of the insert respectively when the screw is tightened, forming an elastic deformation interlocking structure.
[0013] This utility model has the following beneficial effects:
[0014] 1. This utility model has multiple inclined, circumferentially distributed inserts fixedly connected to the bottom end face of the first nut. When the screw is installed, the inserts will be inserted into the object being fastened, forming reverse resistance, effectively preventing the screw from turning counterclockwise and loosening, making the screw more firmly fixed and difficult to disassemble.
[0015] 2. This utility model features a collar fitted onto the top of the screw section. An arc-shaped metal strip, made of elastic metal material, is fixedly connected to the outer surface of the collar. The arc opening direction is consistent with the thread direction of the screw section. When the screw is tightened, the top and bottom of the metal strip will press against the mounting surface and the bottom of the insert block respectively, causing elastic deformation and forming an interlocking structure. This interlocking structure, through the frictional force generated by elastic deformation and the mechanical interlocking effect, further hinders the disassembly of the screw, providing strong protection for the anti-tampering function.
[0016] 3. This utility model uses a clearance fit between the collar and the screw, allowing the collar to slide axially along the screw. This design enables the metal strip to adapt to different installation scenarios. Regardless of changes in the flatness of the mounting surface, the metal strip can adjust its position by sliding, thus ensuring an effective anti-tamper structure under various working conditions and greatly improving the applicability of the device.
[0017] 4. This utility model utilizes the elastic deformation characteristics of the metal strip to adapt to the flatness of different mounting surfaces, ensuring effective interlocking with the mounting surface and the bottom of the insert under various conditions, thus improving the reliability of the anti-disassembly structure. The inclined structure of the insert and the interlocking structure of the metal strip work together to form a dual anti-disassembly mechanism of "mechanical locking + elastic friction", which significantly increases the difficulty of disassembly and can effectively cope with complex working conditions such as vibration and impact, ensuring that the screws remain tight during long-term use. It is suitable for scenarios with extremely high anti-disassembly requirements, such as high-speed rail carriage connectors and power equipment boxes.
[0018] Of course, any product implementing this utility model does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description
[0019] Figure 1 A schematic diagram of the anti-disassembly fastening screws;
[0020] Figure 2 A schematic diagram showing the connection between the screw section, the first nut section, the connecting rod, and the second nut section;
[0021] Figure 3 A schematic diagram of the structure at the top of the anti-disassembly fastening screw;
[0022] Figure 4 This is a schematic diagram showing the structure connecting the screw section, the first nut section, the connecting rod, the second nut section, and the locking block.
[0023] In the diagram: 1. Screw section; 2. First nut section; 3. Connecting rod; 4. Second nut section; 5. Collar; 6. Metal strip; 7. Insert block. Detailed Implementation
[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0025] Please see Figure 1-4 This utility model provides a technical solution: an anti-disassembly fastening screw, including a screw part 1, a first nut part 2 fixedly connected to the top end of the screw part 1, a connecting rod 3 fixedly connected to the top end of the first nut part 2, a second nut part 4 fixedly connected to the end of the connecting rod 3, a special-shaped groove provided on the top surface of the second nut part 4, the outer diameter of the connecting rod 3 being smaller than the outer diameters of the first nut part 2 and the second nut part 4, and an annular weak groove provided in the middle of the connecting rod 3.
[0026] A collar 5 is fitted on the top of the screw part 1. The collar 5 is clearance-fitted with the screw part 1. A plurality of metal strips 6 are fixedly connected to the outer surface of the collar 5. The metal strips 6 are arc-shaped and their two ends are fixed to the top and bottom of the collar 5, respectively.
[0027] Preferably, the metal strip 6 is made of high-quality spring steel, such as 65Mn spring steel. Spring steel has characteristics such as high elastic limit, high fatigue strength and good toughness, which can meet the requirement that the metal strip 6 can withstand repeated compression deformation during the screw tightening process without permanent deformation or breakage.
[0028] The bottom end face of the first nut part 2 is fixedly connected with a plurality of inserts 7, and the plurality of inserts 7 are arranged in an inclined circumferential distribution. The inclination angle of the inserts 7 is 30°-60°. When the screw is tightened, the top and bottom of the metal strip 6 can respectively press and contact the mounting surface and the bottom of the insert 7 to form an elastic deformation interlocking structure.
[0029] Preferably, the insert 7 is made of 45 steel. 45 steel has high strength and good comprehensive mechanical properties, which can meet the strength requirements required when the insert is inserted into the object being fastened. To further enhance the wear resistance and corrosion resistance of the insert 7, its surface is subjected to quenching and blackening treatment. The quenching treatment can significantly increase the surface hardness of the insert 7, effectively enhancing its wear resistance when inserted into the object being fastened, and preventing the insert from being worn due to friction, thus affecting the anti-loosening effect. The blackening treatment forms a dense oxide film on the surface of the insert. This oxide film can not only improve the corrosion resistance of the insert and extend its service life, but also enhance the friction between the insert and the object being fastened to a certain extent, further improving the anti-loosening effect of the insert 7.
[0030] During installation, screw 1 is screwed into the object to be fastened, and collar 5 moves down with screw 1. Insert block 7 on the bottom end of first nut 2 is inserted into the surface of the object, forming a reverse resistance. A special tool is used to apply torque to second nut 4. The torque is transmitted to first nut 2 through connecting rod 3. As the tightening force increases, stress concentrates at the weak groove of connecting rod 3 and exceeds the material yield strength. When the torque increases beyond the limit according to the material strength, the weak groove breaks, and second nut 4 falls off from connecting rod 3.
[0031] During tightening, the collar 5 slides downward along the axial direction of the screw portion 1, the top of the metal strip 6 contacts the mounting surface and is squeezed and bent inward, and the bottom contacts the bottom of the insert 7 on the bottom end face of the first nut portion 2. Since the insert 7 is distributed at an inclination of 30°-60°, when the screw is tightened, the insert 7 is inserted into the connected part, and its bottom exerts an upward oblique thrust on the metal strip 6, causing the metal strip 6 to deform further. The top and bottom are squeezed and contacted with the mounting surface and the bottom of the insert 7 respectively, forming an elastic deformation interlocking structure.
[0032] After the breakage, only the screw part 1 and the first nut part 2 remain fixed on the connected parts, and there are no tool slots on the surface of the first nut part 2. At the same time, the interlocking resistance structure of the insert block 7 and the metal strip 6 still exists, effectively preventing illegal disassembly.
[0033] This utility model significantly improves the fastening reliability and anti-disassembly performance of screws through a multi-layer anti-disassembly structure design, and is suitable for high-security protection scenarios that require anti-tampering, such as high-speed rail carriage connectors, power equipment boxes, outdoor equipment, and security facilities.
[0034] The preferred embodiments of this utility model disclosed above are merely illustrative of the present utility model. These preferred embodiments do not exhaustively describe all details, nor do they limit the utility model to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.
Claims
1. A tamperproof fastening screw comprising a shank portion (1), characterized in that: The top end of the screw part (1) is fixedly connected to a first nut part (2), the top end of the first nut part (2) is fixedly connected to a connecting rod (3), and the end of the connecting rod (3) is fixedly connected to a second nut part (4). The top of the screw part (1) is fitted with a collar (5), and a plurality of metal strips (6) are fixedly connected to the outer surface of the collar (5). The metal strips (6) are arc-shaped and their two ends are fixed to the top and bottom of the collar (5) respectively. The bottom end face of the first nut part (2) is fixedly connected with a plurality of inserts (7), and the plurality of inserts (7) are arranged in an inclined circumferential distribution.
2. A tamper-resistant security screw according to claim 1, wherein, The top surface of the second nut part (4) is provided with an irregular groove.
3. The tamper-resistant security screw of claim 1, wherein: The outer diameter of the connecting rod (3) is smaller than the outer diameter of the first nut part (2) and the second nut part (4), and the middle part of the connecting rod (3) is provided with an annular weak groove.
4. The tamper-resistant security screw of claim 1, wherein, The collar (5) is clearance-fitted with the screw (1).
5. The tamper-resistant security screw of claim 1, wherein: The inclination angle of the insert (7) is 30°-60°. When the screw is tightened, the top and bottom of the metal strip (6) can be pressed and contacted with the mounting surface and the bottom of the insert (7) respectively to form an elastic deformation interlocking structure.