JPH11336734A - Nut removal preventing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent removing of a nut due to mischief or the like. SOLUTION: A bolt 7 screwed into a nut 8 to tighten an article is screwed into a receiving board 1 to the more forward side than the nut 8. A covering tube 4 which covers the roughly whole range of the outer-periphery surfaces of the receiving board 1 and the nut 8 is rotatably-assembled onto the receiving board 1. A locking part piece 6 locked on the single surface on the nut 7 side of the receiving board 1 is projected inside the covering tube 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fastening device in which a nut is screwed into a bolt to fasten an article, such as fixing a pair of plate materials to each other or to a concrete structure, and the nut cannot be removed by mischief. Thus, the present invention relates to a nut removal preventing device.

[0002]

2. Description of the Related Art A fastening device in which an article is fastened with a bolt and a nut is scattered as an existing device such as an example in which angle steels forming a tower of a transmission line are fastened to each other. The nut can be detached freely by using.

[0003] However, in recent years, there has been an increasing tendency that nuts are removed due to mischief or the like, and corresponding means have been studied.

[0004] The present invention has been made in view of such a normal situation.

[0005]

A receiving plate is screwed to a bolt to which an article is fastened by screwing a nut, and a receiving plate is screwed to the distal end side of the nut, and substantially the entire outer peripheral surface of the receiving plate and the nut. A structure in which a sleeve for covering the receiving plate is rotatably assembled to the receiving plate, and a locking portion that locks to one surface of the receiving plate on the nut side is protruded inside the sleeve. You do it.

[0006]

The outer circumference of the nut and the receiving plate are covered by the sleeve, so that the rotation operation is prevented from the outside. Even if the sleeve is rotated, the sleeve is free with respect to the receiving plate. And the locking piece is locked to the receiving plate, thereby preventing removal of the receiving plate, that is, the nut.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of a nut removal preventing device according to the present invention.
'Is applied to the nut 8 side of a fastening device in which the device of the present invention is fastened by a bolt 7 and a nut 8 screwed to the bolt 7. For example, the nut is attached to an anchor bolt projecting from a concrete structure The present invention is applied to various fastening devices using bolts and nuts, such as fixing screws of the equipment to the concrete structure by screwing.

FIG. 1 shows a receiving plate made of metal. The receiving plate 1 is a circular ring having a screw hole 2 provided inside and a receiving hole 3 for holding a tool. , Which are screwed and assembled on the tip side of the nut 8.

The receiving hole 3 is for locking the tip of the tool to the receiving hole 3 so that the receiving plate 1 can be more securely fastened to the bolt 7.

Reference numeral 4 denotes a metal jacket formed of a bottomed tubular body having an upper surface 4a and a cylindrical portion 4b. The jacket 4 has a through hole for the bolt 7 at the center of the front upper surface 4a. With 5,
The receiving plate 1 is formed by projecting locking portions 6 inwardly at equal intervals at four positions on the peripheral side of the cylindrical portion 4b on the upper surface portion 4a side.
And the nut 8 is rotatably mounted on the receiving plate 1 so as to cover substantially the entire outer peripheral surfaces 1a and 8a of the nut 8, and the locking piece 6 is provided on the nut 8 side of the receiving plate 1 on the nut 8 side. It is arranged at a position to be locked on one side 1b.

However, the operation of removing the bolt 7 from the bolt 7 by rotating the nut 8 as well as the receiving plate 1 is prevented by the presence of the jacket 4. Because of the free rotation, the removal of the nut 8 by the rotation operation of the sleeve 4 is also prevented, and even if the sleeve 4 is to be moved in the axial direction of the bolt 7, the locking piece 6 is attached to the receiving plate 1. The movement is restricted by locking, and the removal of the nut 8 is prevented.

In order to obtain the embodiment, the receiving plate 1 is screwed to a bolt 7 to which a nut 8 is screwed, and the sleeve 4 is moved so that the through hole 5 is aligned with the bolt 7. When pressed (or hit) in the directions b and b ', the sleeve 4 moves in the pressing direction, and the locking piece 4b projecting from the inside of the sleeve 4b of the sleeve 4 is elastically deformed and received. The receiving plate 1 is located on the one surface 1b side of the plate 1 and is interposed between the locking portion piece 4b and the upper surface portion 4a of the jacket, and has an inner diameter larger than the outer diameter of the receiving plate 1 and the nut 8. The sleeve 4 is rotatably assembled to these, and a nut removal preventing state can be obtained.

The outer diameter of the receiving plate 1 is larger than that of the nut 8, and the locking portion 4b is locked to the one surface 1b of the receiving plate 1 by increasing the outer diameter.

Although the sleeve 4 of the embodiment has the upper surface 4a, the upper surface 4a may be omitted. In this case, the gap between the sleeve and the receiving plate is defined by a finger or a finger. It should be so narrow that no tools can be inserted. By providing the upper surface portion 4b, the degree of the widening and narrowing of the gap becomes free.

[0015]

The present invention has the configuration described above,
The removal of the nut can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Receiving plate 4 Cloth sleeve 6 Locking piece 7 Bolt 8 Nut

Claims (1)

[Claims] 1. A receiving plate is screwed to a bolt to which an article is fastened by screwing a nut so that the receiving plate is located on the tip side from the nut, and covers substantially the entire outer peripheral surface of the receiving plate and the nut. A sleeve is rotatably assembled to the receiving plate, and inside the sleeve,
A nut removal prevention device, wherein a locking portion that locks to one surface of the receiving plate on the nut side protrudes.