JPH11311235A - Mischief preventive fitting for nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a bolt and a nut fitted to a fastened member from being removed by mischief. SOLUTION: A mischief preventive fitting 1 is composed of a fixed ring 2 thread-fastened to the end part of a bolt B, and a protective cap 3 locked to the fixed ring 2 while covering the end part of the bolt B and a nut N. The outer diameter of the fixed ring 2 is made larger than that of the nut N. The protective cap 3 has a bowl-like part 7 consealing the nut N and the protruding end part of the bolt B inside, and a locking part 8 for locking the bowl-like part 7 to the fixed ring 2. The locking part 8 is composed of a plurality of folded spring pieces 8a. The folded spring pieces 8a rise inclining onto the inside of the bolt-like part 7 from the open side edge of the bowl-like part 7, and the arranged inner diameter of the tip parts is formed to be smaller than the outer diameter of the fixed ring 2. When the protective cap 3 is put over the upper part of the fixed ring 2 and driven, the folded spring pieces are engaged with the nut N side of the fixed ring 2 to stop slip-off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prevents a bolt or a nut used for tightening a connection flange portion of a steel pipe or an angle iron, for example, constituting a main leg of a power transmission tower from being unnecessarily loosened by an outsider. Therefore, the present invention relates to metal fittings mounted on bolts and nuts.

[0002]

2. Description of the Related Art Conventionally, no special measures have been taken to protect bolts and nuts attached to, for example, main legs of a power transmission tower from intentional removal by outsiders. Recently, however, the necessity of a technique for preventing tampering of nuts has come to be considered in the wake of the collapse of a power transmission tower caused by the removal of bolts and nuts by outsiders due to mischief.

[0003]

SUMMARY OF THE INVENTION The present invention is mounted so as to cover bolts and nuts to prevent the bolts and nuts attached to a member to be tightened such as a steel pipe for a tower from being removed by tampering. It is an object of the present invention to provide a metal fitting that is easy to attach and difficult to remove.

[0004]

Means for Solving the Problems In the first invention,
A fixing ring 2 screwed to an end of the bolt B;
And the protective cap 3 which covers the end portion of the nut N and is fixed to the fixing ring 2 to constitute the tamper-proof fitting 1. At least a part of the outer diameter of the fixing ring 2 is larger than the diameter of the nut N. The protective cap 2 has a bowl-shaped portion 7 for sealing the protruding ends of the nut N and the bolt B therein, and a locking portion for locking the bowl-shaped portion 7 to the fixing ring 2 therein. And a unit 8. The locking portion 8 has at least a part of the inner diameter smaller than the outer diameter of the protective cap 3, and when the locking portion 8 is driven while being expanded to the outside of the fixing ring 2, it passes through the fixing ring 2 and is It is configured to engage with the surface on the nut N side. Once the protective cap 3 is mounted, it is locked to the fixing ring 2 inside the bowl-shaped portion 7, so that it is difficult to release the lock from the outside and remove it. In the second invention, the protective cap 3 has a bowl-shaped portion 7 for sealing the protruding ends of the fixing ring 2, the nut N and the bolt B therein.
And a plurality of folded spring pieces 8a for locking the bowl-shaped portion 7 to the fixing ring 2 inside thereof. The return spring piece 8a rises from the open side edge of the bowl-shaped portion 7 to the inside of the bowl-shaped portion 7 and gradually decreases its array inner diameter toward the tip. It is formed so as to be smaller than the outer diameter of. When the protection cap 3 is driven into the outside of the fixed ring 2 while expanding the diameter of the return spring piece 8a, the tip of the return spring piece 8a passing through the fixed ring 2 engages with the surface of the fixed ring 2 on the nut N side. It can be prevented from falling out. In the third aspect, the protective cap 10 has a concave portion 1 recessed inward from an outer diameter of the fixing ring 2 in order to lock the fixing ring 2.
3 and an open side edge whose inner diameter is larger than the outer diameter of the fixing ring 2. When the protective cap 13 is driven into the outside of the fixing ring 2 while expanding its diameter, the concave portion 13 that has passed through the fixing ring 2 engages with the surface of the fixing ring 2 on the nut N side and is prevented from coming off. In the fourth invention, the protective cap 16 has an inner diameter on the small diameter side smaller than the outer diameter of the fixing ring 2 and an inner diameter on the large diameter side larger than the outer diameter of the fixing ring 2 in order to engage with the fixing ring 2. The tapered portion 19 is formed.
When the protective cap 16 is driven into the outside of the fixing ring 2 while expanding in diameter, the small-diameter portion 18 that has passed through the fixing ring 2
Is engaged with the surface of the fixing ring 2 on the nut N side to prevent the fixing ring 2 from coming off.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of the tamper-proof bracket in the mounted state, FIG. 2 is a plan view of the tamper-proof bracket in the mounted state with a part cut away, FIG. 3 is a longitudinal sectional view of the protective cap, and FIG. FIG. 5 and FIG. 5 are longitudinal sectional views of a tamper-proof metal fitting using a protective cap according to another embodiment, FIG. 6 is a plan view of a part of the tamper-proof metal fitting in a mounted state, and FIG. 7 is still another embodiment. FIG. 8 is a cross-sectional view of the tamper-proof bracket using the protective cap shown in FIG. In FIGS. 1 to 4, the tamper-proof metal fitting 1 for the nut is a bolt B
And a protective cap 3 which is engaged with the fixing ring 2 so as to cover the end of the bolt B and the nut N. The fixing ring 2 has a screw hole 3 in the center.
The outer diameter of the ring is larger than the outer diameter of the nut N. The fixing ring 2 has six engagement holes 4 for engaging a dedicated tool (not shown) for a rotation operation of screwing the bolt into the bolt B, and a wedge 5 for screwing the bolt into the bolt B and fixing it to the bolt. And a wedge hole 6 for driving.

As shown in FIGS. 3 and 4, the protective cap 3 has a bowl-shaped portion 7 for sealing the protruding ends of the fixing ring 2, the nut N and the bolt B therein. And a locking portion 8 for locking the fixing ring 2 inside the fixing ring 2. The locking portion 8 is composed of four folded spring pieces 8a. The folded-back spring piece 8a rises from the open side edge of the bowl-shaped part 7 to the inside of the bowl-shaped part 7 and gradually reduces the array inner diameter toward the inside of the closed end of the bowl-shaped part 7, The distal end portions are arranged such that the inner diameter is smaller than the outer diameter of the fixing ring 2.

In the nut tamper-proof fitting 1 of this embodiment, for example, a connection flange portion of a steel pipe constituting a main leg of a power transmission tower is tightened with a bolt B and a nut N, and then the fixing ring 2 is bolted with a special tool. B is screwed, and the wedge 5 is driven into contact with the nut N and fixed. Next, the protective cap 3 is put on the upper part of the fixing ring 2 and is driven in the axial direction of the bolt B. At this time, when the return spring piece 8a passes through the fixed ring 2 while elastically expanding its diameter to the outside of the fixed ring 2, its tip goes around and engages with the lower surface of the fixed ring 2 projecting from the nut N. Therefore, once the protective cap 3 is mounted, the protective cap 3 is locked to the fixing ring 2 inside the bowl-shaped portion 7, and it is difficult to release the lock from the outside and remove it.

Another embodiment is shown in FIGS. In the drawing, the same components as those in the previous embodiment are denoted by the same reference numerals, and description thereof is omitted. In the protective cap 10 of the nut mischief prevention metal fitting 9, a bowl-shaped part 11 for sealing the protruding end of the bolt B inside,
An overhang portion 12 for receiving the fixing ring 2 and a small-diameter portion 1 for locking the protective cap 10 to the fixing ring 2.
3 and a tapered portion 14 that seals the nut N continuously to the small diameter portion 18. The inside diameter of the small diameter portion 13 is smaller than the outside diameter of the fixed ring 2, and the inside diameter of the open side edge of the tapered portion 14 is formed larger than the outside diameter of the fixed ring 2.

In the nut tampering prevention fitting 11 of this embodiment, the bolt B and the nut N are tightened, the fixing ring 2 is screwed to the bolt B, and the wedge 5 is used. Secure and protect cap 1
2 is put on the fixing ring 2 and driven. When the small-diameter portion 13 passes through the fixed ring 2 while the tapered portion 14 elastically expands outside the fixed ring 2 by the driving, the fixed ring 2 fits into and engages with the overhang portion 12. Therefore, when the protective cap 12 is mounted, it is locked to the fixing ring 2, so that it is difficult to release the lock from the outside and remove it.

[0010] Still another embodiment is shown in FIGS. The protection cap 16 of the nut tamper-proof metal fitting 15 has a bowl-shaped portion 17 for sealing the protruding ends of the fixing ring 2 and the bolt B therein, and a locking portion 17 for locking the protection cap 16 to the fixing ring 2. The small-diameter portion 18 includes a tapered portion 19 that seals the nut N continuously from the small-diameter portion 18. The inside diameter of the small diameter portion 18 is smaller than the outside diameter of the fixed ring 2, and the inside diameter of the edge of the tapered portion 19 is larger than the outside diameter of the fixed ring 2.

Also in the nut mischief prevention bracket 15 of this embodiment, the bolt B and the nut N are tightened, the fixing ring 2 is screwed to the bolt B, and the wedge 5 is used. Secure and protect cap 1
6 is put over the upper part of the fixing ring 2 and driven. If the small-diameter portion 18 passes through the fixed ring 2 while the tapered portion 19 elastically expands outside the fixed ring 2 by the driving, the fixed ring 2 reaches the inside of the bowl-shaped portion 17 and is prevented from falling off at the small-diameter portion 18. . Therefore, when the protective cap 16 is mounted, it is locked to the fixing ring 2, and it is difficult to release the lock from the outside and remove it.

In the above embodiment, the protective cap is constructed as described above. However, at least a part of the inner diameter of the protective cap is provided, for example, by providing a concave portion projecting inward from the outer diameter of the fixing ring instead of the small diameter portion and the tapered portion. However, when it is smaller than the outer diameter of the protective cap and is driven while expanding its diameter to the outside of the fixing ring, it may pass through the fixing ring and engage with the surface of the fixing ring on the nut side.

[0013]

As described above, the present invention can be easily attached to bolts and nuts, making it difficult to remove these bolts and nuts, and securing bolts and nuts attached to a member to be fastened such as a steel pipe for a tower. This has the effect of preventing removal by mischief and preventing accidents such as collapse of the transmission line tower.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a tamper-proof metal fitting in a mounted state.

FIG. 2 is a plan view in which a part of a tamper-resistant metal fitting in a mounted state is cut away.

FIG. 3 is a longitudinal sectional view of a protective cap.

FIG. 4 is a bottom view of the protective cap.

FIG. 5 is a vertical cross-sectional view of a tamper-proof metal fitting of another embodiment.

FIG. 6 is a plan view in which a part of a tamper-resistant metal fitting in a mounted state is cut away.

FIG. 7 is a vertical cross-sectional view of a tamper-proof bracket according to still another embodiment.

FIG. 8 is a plan view in which a part of the tamper-proof metal fitting in a mounted state is cut away.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tamper-proof metal fitting 2 Fixing ring 3 Protective cap 7 Bow-shaped part 8 Locking part 8a Folding spring piece 9 Tamper-proof metal fitting 10 Protective cap 11 Bow-shaped part 13 Small diameter part 14 Tapered part 15 Tamper-resistant metal fitting 16 Protective cap 17 Bow-shaped part 18 Small diameter part 19 Taper part B Bolt N Nut

Claims (4)

[Claims] 1. A metal fitting to be attached to a bolt or a nut for preventing a bolt or a nut attached to a member to be tightened from being removed by mischief, wherein at least a part has a diameter larger than that of the nut and protrudes from the nut. A fixing ring that is screwed to the projected portion of the bolt, and a protection cap that seals the fixed ring, the protruding end of the nut and the bolt inside, and is internally locked to the fixing ring, The protective cap has at least a portion of the inner diameter smaller than the outer diameter of the fixing ring, and when the protective cap is driven while being expanded to the outside of the fixing ring, the protective cap passes through the fixing ring and faces the nut side of the fixing ring. A metal tamper-proof fitting, wherein the metal tamper-proof fitting is configured to engage with the nut. 2. The protection cap according to claim 1, wherein the fixing ring includes:
A bowl-shaped part for sealing the protruding ends of the nut and the bolt therein, and a plurality of folded spring pieces for locking the bowl-shaped part to a fixing ring inside the bowl-shaped part; The piece rises inclining from the open side edge of the bowl-shaped portion to the inside of the bowl-shaped portion, gradually reduces the array inner diameter toward the tip, and the array inner diameter of the tip portion is smaller than the outer diameter of the fixing ring. When the protective cap is driven into the outside of the fixing ring while expanding the diameter of the return spring piece, the tip of the return spring piece that has passed through the fixation ring is located on the nut side of the fixation ring. The tamper-evident metal fitting of claim 1, wherein the metal buckle is configured to engage with a surface. 3. The protection cap includes a concave portion recessed inward from an outer diameter of the fixing ring for engaging with the fixing ring, and an open-side edge having an inner diameter larger than an outer diameter of the fixing ring. The concave portion having passed through the fixing ring is configured to be engaged with a nut-side surface of the fixing ring when the fixing ring is driven into the outside of the fixing ring while expanding its diameter. Nut tamper-proof bracket. 4. The protective cap has a tapered surface whose inner diameter on the small diameter side is smaller than the outer diameter of the fixing ring and whose inner diameter on the large diameter side is larger than the outer diameter of the fixing ring for engaging with the fixing ring. The small diameter portion that has passed through the fixing ring is configured to engage with a nut-side surface of the fixing ring when driven into the fixing ring while being expanded in diameter. The tamper-proof metal fitting of the nut according to 1.