Security bolt

Abstract

To provide a practical security bolt which is less likely to be removed illicitly because an engagement structure between a head and a tool is not recognized from the outside and can be removed easily when necessary.SOLUTION: A security bolt 1 comprises: a bolt body 2 formed by connecting a head 9, having a diameter larger than that of a screw shaft 4 and provided with an engaged part 6 capable of engaging with a tool, with a base end of the columnar screw shaft 4 in which a screw groove is engraved on an outer periphery; and a cap 3 for covering the head 9 of the bolt body 2 which is formed by a deformable metal thin plate. Further, the cap 3 is formed into a semi-spherical shape and a recessed part 7 functioning as a dummy engagement recessed part having a non-columnar shape is formed at a top part of the cap 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bolt for fastening that has a security function. [Background technology]

[0002] Bolts and nuts are used as fastening members in a variety of applications because they can hold multiple components in a fastened state and can easily release that fastening state when necessary. However, in applications such as vehicle license plates and key cylinders in the steering parts of automobiles and motorcycles, it is desirable that the fastening state cannot be easily released in order to prevent crimes such as theft.

[0003] For this reason, security bolts have been developed in which the head (head portion) is formed in a shape other than the usual flat hexagonal column and is configured so that the fastened state cannot be released without the use of a special tool, as well as security bolts with a cover attached to the head to prevent it from being removed.An example of such a security bolt with a cover attached to the head is one disclosed in Patent Document 1, which is composed of a bolt body with a circumferential groove formed on the periphery of the head, and a cylindrical cover made of spring material with multiple claw-shaped stoppers protruding inward on the periphery, and the claw-shaped stoppers of the cover engage with the circumferential grooves on the head of the bolt body, thereby covering the head of the bolt body with a cover that is difficult to remove. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-116031 Summary of the Invention [Problem to be solved by the invention]

[0005] However, while security bolts with specially shaped heads that can only be engaged with special tools provide a certain level of security, it is difficult to maintain a high level of security over the long term because it is possible to form (imitate) special tools to fit the shape of the head.On the other hand, security bolts of the type in which the head of the conventional bolt body is covered with a cover, such as those in Patent Document 1, have the disadvantage that the cover must be formed to fit the shape of the head, which increases manufacturing costs and makes it difficult to easily remove the cover when it is necessary to release the fastened state.

[0006] The object of the present invention is to solve the problems of the above-mentioned conventional security bolts, to provide a practical security bolt in which the head structure is not visible from the outside, making it difficult to remove illegally, and which can be easily removed when it becomes necessary to release the fastened state. [Means for solving the problem]

[0007] The invention described in claim 1 of the present invention is a security bolt consisting of a bolt body having a cylindrical screw shaft with a screw groove on the outer periphery and a head portion provided with an engaged portion that can be engaged with a tool, and a cap for covering the head portion, wherein the cap is made of a deformable thin plate. The dummy engagement recess is formed in a non-cylindrical shape at the top. It is characterized by:

[0008] In the invention described in claim 1, the engaged portion is , only with tools of specific shapes Engage possible It's fine if it's something like that.

[0010] Claim 2 The invention described in The invention described in claim 1 In the above, the surface of the cap is Engaged part The shape of the device is displayed with information related to it. [Effects of the Invention]

[0011] The security bolt described in claim 1 has a high security function because the head of the bolt body is covered with a cap (cover) and the tool engagement structure (so-called drive part) of the head cannot be seen from the outside. On the other hand, if it becomes necessary to release the fastening, a qualified worker who is informed in advance of the shape and structure of the security bolt can easily remove the cap by pressing a tool that matches the engaged part of the head from above and deforming the cap made of thin metal plate to fit the shape of the engaged part. Furthermore, the security bolt described in claim 1 has a dummy engagement recess (i.e., a false drive structure to deceive someone intending unauthorized removal) at the top of the hemispherical body of the cap, and even if someone intending unauthorized removal inserts a tool that matches the shape of the dummy engagement recess and rotates it, the tool will simply spin freely, making it more difficult to understand the structure for rotating the head of the bolt body, thereby providing a very high level of security.

[0012] If the engaged part of the security bolt is shaped so that it can only be engaged with a tool of a specific shape, Unless a tool of a specific shape (such as a wrench with a triangular prism-shaped recess) that matches the shape of the engaged part of the head (such as a specific shape such as a triangular prism) is pressed from above the cap, the cap cannot be deformed to fit the shape of the engaged part, thereby providing a higher level of security.

[0014] Claim 2 The security bolt described in the above can be easily opened by a qualified worker who is informed of the shape and structure of the security bolt in advance, based on the information displayed on the surface of the cap. Engaged part Therefore, when it becomes necessary to release the fastening, it can be removed very easily. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is an explanatory diagram (front view) showing a security bolt. [Figure 2] FIG. 1 is an explanatory diagram (plan view) showing a security bolt. [Figure 3] 3 is an explanatory diagram showing a cross section of the cap (a cross section taken along line AA in FIG. 2). FIG. [Figure 4] This is an explanatory diagram (front view) showing how to use a security bolt (a) shows the state in which a fastener is fastened to a fastened object by the bolt body and nut, and b shows the state in which a cap is attached to the head of the bolt body). [Figure 5]An explanatory diagram showing how to use the security bolt (a shows the state in which a tool is placed on top of the cap so that it can engage with the engaged part of the head of the bolt body, and b shows the state in which a tool is engaged with the engaged part of the head of the bolt body from above the cap). [Figure 6] FIG. 10 is an explanatory diagram (plan view) showing a modified example of the cap. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a security bolt according to the present invention will now be described in detail with reference to the drawings.

[0017] <The structure of the security bolt> Figures 1 and 2 show a security bolt, with security bolt 1 comprising a bolt body 2 and a cap (cover) 3. Bolt body 2 is integrally formed from metal (stainless steel), and a head (head portion) 9 with a larger diameter than the screw shaft 4 is attached to the base end of a cylindrical screw shaft 4 with a screw groove (thread formed) on the outer periphery. Head 9 comprises a base portion 5 formed in the shape of a flat truncated cone and an engaged portion 6 in the shape of a flat hexagonal pillar provided above base portion 5. The upper periphery of engaged portion 6 is chamfered in an R-shape. A flat cylindrical pedestal portion is formed below base portion 5.

[0018] Meanwhile, cap 3 is formed in a roughly hemispherical shape (hollow hemispherical shape) from a thin metal (stainless steel) plate with a thickness of 20 μm, with the outer periphery folded inward at a fixed width to form folded portion 8 (see FIG. 3). A flat hexagonal column-shaped recess 7 that functions as a dummy engagement recess is formed at the top (the central part of the hemisphere). In addition, three indicator lines 10, 10... are printed on the outer surface of cap 3 in a direction radiating from the center, at equal intervals from each other (at equal angles to the center).

[0019] <How to use and function of the security bolt> Figures 4 and 5 show how to use the security bolt 1 configured as described above. When fastening a fastener O to a fastened object B with the security bolt 1, as shown in Figure 4(a), a nut N is screwed onto the tip of the screw shank 4 of the security bolt 1, which has been inserted through the screw insertion holes of the fastener O and the fastened object B, and tightened. Thereafter, as shown in Figure 4(b), a cap 3 is attached to the head 9 of the bolt body 2. When attaching the cap 3 to the head 9 of the bolt body 2 in this way, the cap 3 can be easily attached to the head 9 by pressing the cap 3 downward with the inner peripheral edge of the folded portion 8 abutting against the peripheral edge of the truncated cone-shaped base portion 5 of the head 9. Furthermore, when attaching the cap 3 to the head 9 of the bolt body 2 in this manner, the direction of the three indication lines 10, 10·· is aligned with the vertical ridge line on the outer periphery of the flat hexagonal column-shaped engaged portion 6 formed on the head 9 (see Figure 4(c)).

[0020] As described above, the head 9 of the security bolt 1 used to fasten the fastener O and the fastened object B is covered by the opaque cap 3, and a person who wants to illegally remove the security bolt 1 cannot recognize the shape of the head 9 (the shape of the engaged portion 6) from the outside of the cap 3, and therefore cannot remove it.

[0021] On the other hand, if it becomes necessary to release the fastening, an authorized worker (i.e., a worker who is previously informed of the shape and structure of the security bolt 1) can easily use an appropriate tool (e.g., a wrench) to rotate the security bolt 1 and release the fastening. FIG. 5 shows the process of releasing the fastening by the security bolt 1. As shown in FIG. 5(a), the worker releasing the fastening can position an appropriate tool (e.g., a wrench) T that matches the shape of the engaged portion 6 of the head 9 (the distance between the two parallel faces of the engaged portion 6, which is a flat hexagonal column) so that it engages with the engaged portion 6, based on the indicator lines 10, 10... printed on the cap 3. That is, by aligning the direction of the midpoint line L between the two parallel faces of the tool T with one of the indicator lines 10, 10..., the worker can align the phase (orientation in the horizontal plane) of the tool T with the phase of the engaged portion 6 of the head 9 (i.e., the hexagonal column) inside the cap 3.

[0022] Then, after aligning the phase of tool T with the phase of engaged portion 6 of head 9 inside cap 3 as described above, the worker presses tool T onto head 9 from above (from the outside) of cap 3. When the worker presses tool T onto head 9 from above (from the outside) of cap 3 in this way, cap 3, which is made of a thin metal plate, deforms according to the shape of tool T and the shape of engaged portion 6 of head 9, as shown in FIG. 5(b), and is sandwiched between tool T and engaged portion 6 of head 9, and with cap 3 interposed between them, the two parallel surfaces of tool T and the two parallel surfaces of engaged portion 6 of head 9 abut against each other. This allows the worker to rotate and remove security bolt 1 using tool T.

[0023] <Effects of security bolts> As described above, the security bolt 1 has a high level of security because the head 9 of the bolt body 2 is covered by the cap 3 made of a deformable thin metal plate, and the structure of the head 9 that engages with the tool T cannot be seen from the outside. On the other hand, if it becomes necessary to release the fastening, an authorized worker (i.e., a worker who has been informed in advance of the shape and structure of the security bolt 1) can easily remove the cap 3 with the tool T by pressing the tool T that matches the engaged portion 6 of the head 9 from above the cap 3 and deforming the cap 3 made of thin metal plate to fit the shape of the engaged portion 6.

[0024] Furthermore, the security bolt 1 has a hemispherical cap 3 with a non-cylindrical recess (dummy engagement recess) 7 formed at the top, and even if a person intending to illegally remove it inserts a tool T' that matches the shape of the recess 7 and rotates it, the tool T' will simply spin freely, making it more difficult to understand the structure for rotating the head 9, thereby providing a very high level of security.

[0025] In addition, the security bolt 1 has a head 9 on the surface of the cap 3. Engaged part Indication lines 10, 10... are printed on the surface of the cap 3 as information related to the shape of the head 9. Engaged part Since the phase (orientation in the horizontal plane) of 6 can be grasped, it can be removed very easily if it becomes necessary to release the fastening.

[0026] <Example of changing the security bolt> The security bolt according to the present invention is not limited to the above-described embodiments, and the materials, shapes, structures, and other configurations of the bolt body and cap can be modified as needed without departing from the spirit of the present invention. For example, the security bolt according to the present invention is not limited to bolts and caps made of stainless steel, as in the above-described embodiments, but the bolt body and / or cap may be made of other metals, such as iron or aluminum. In addition, the cap is not limited to those made of a deformable thin metal plate, as in the above-described embodiments, but may be made of a deformable thin plate made of synthetic resin, for example.

[0027] Furthermore, the security bolt of the present invention is not limited to the above embodiment in which the engaged portion of the head of the bolt body is a flat hexagonal prism, but can also be modified to have an engaged portion in the shape of a triangular prism, square prism, pentagonal prism, octagonal prism, etc. (i.e., one that can only engage with tools of a specific shape), or an engaged portion that is a cylindrical body with a minus or plus screw groove engraved on it, etc.

[0028] On the other hand, the cap is not limited to being formed from a thin plate made of stainless steel as in the above embodiment, and can be changed to being formed from a thin plate made of other metals. Note that if a cap made from a thin plate made of stainless steel or iron and having a thickness of 10 to 100 μm is used, when an appropriate tool is pressed against it from above (from the outside), it will easily deform to fit the shape of the tool and the shape of the engaged portion of the head of the bolt body without applying a large force, which has the advantage that it becomes very easy to release the fastening of the security bolt.

[0029] In addition, the cap is not limited to the above embodiment in which an indication line relating to the phase (direction in the horizontal plane) of the engaged portion of the head of the bolt body is printed. Engaged part The cap may not display information related to the shape of the dummy engaging recess, or, as shown in Fig. 6(a), information related to the shape and structure of the engaged portion of the head of the bolt body (for example, the distance between the two parallel faces of the hexagonal columnar body) may be displayed by a barcode or a code agreed upon between the parties (display section 11). Engaged part (For example, as in the above embodiment, the horizontal cross-sectional shape of the dummy engagement recess is Engaged part The horizontal cross-sectional shape of the bolt is the same as that of the bolt head. Engaged part The adoption of such a configuration has the advantage that a qualified worker can reliably release the fastened state in a short time using an appropriate tool.

[0030] Furthermore, in order to make it easier to attach the cap to the head of the bolt body, the cap may have notches 12, 12... on its peripheral edge (for example, the folded portion), as shown in Figure 6(b). In addition, the cap is not limited to the type that can be attached to the head of the bolt body by an operator without using tools, as in the above embodiment, but may be a type that is attached so that it cannot be removed by placing it so as to cover the head of the bolt body and then caulking the peripheral edge, etc. [Industrial Applicability]

[0031] As described above, the anti-theft bolt of the present invention has excellent anti-theft effects and can therefore be suitably used as a fastening member for applications where normal removal is not expected, such as vehicle license plates and key cylinders in the steering parts of automobiles and motorcycles. [Explanation of symbols]

[0032] 1. Anti-theft bolt 2. Bolt body 3··Cap 6. Engaged part 7. Recess (dummy engagement recess) 9...Head 10...Display line 11...Display section O··Fasteners B. Fastening garment

Claims

1. A security bolt consisting of a bolt body formed by connecting a head provided with an engaged portion that can be engaged with a tool to the base end of a cylindrical screw shaft with a screw groove on the outer periphery, and a cap for covering the head, A security bolt characterized in that the cap is opaque and made of a deformable thin plate, is formed in a hemispherical shape, and has a non-cylindrical dummy engagement recess formed at the top.

2. 2. The security bolt according to claim 1, wherein information relating to the shape of the engaged portion of the head is displayed on the surface of the cap.

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