JP2000055022A - Irreversible nut and spanner used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an irreversible nut having a simple structure in which a thread engagement thereof with a bolt is not released by a tool in the case where the nut is once thread-engaged with the bolt. SOLUTION: In this irreversible nut, a plurality of stepped portion 5 are provided on a top surface 4 at a small diameter side of a top cut cone; an inclined surface 6 is formed from an upper step portion 5a of one stepped portion 5 toward a lower step portion 5b of the other stepped portion 5, an inclined surface 6 is also formed on the other stepped portion 5 similarly and a female screw 9 engaged with a male screw is provided on an inner periphery of the top-cut cone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-reversible nut in which a nut once screwed to a bolt cannot be disengaged from the bolt depending on a tool, and a spanner used therefor.

[0002]

2. Description of the Related Art Conventionally, bolts and nuts used for fixing towers, pillars, rails, etc. are removed from the bolts by mischief or the like, and the tower or pole is dropped, rails are removed, or the rails are moved. Problems have arisen, and we are struggling to take countermeasures.

On the bolt side, not on the nut side, the shape of the bolt is made possible by a locking means in the screw tightening direction and is not caught in the screw returning direction. Inventions and ideas are described in Japanese Utility Model Laid-Open No. 2-41714, Japanese Utility Model Laid-Open No. 3-89211, and Japanese Patent Application Laid-Open No. 9-264312. Japanese Patent Laid-Open Publication No. Sho 61-196008 discloses a technique in which a bolt head and a nut are covered with a resin cap.

[0004]

However, these conventional means require a specially shaped bolt head, which is troublesome to manufacture, and a screw or tool having a shape conforming to the special shape is required for tightening the screw. There are drawbacks that require tools,
Further, when a large torque is required to tighten the screw, the specially shaped engaging portion is deformed by a tightening load from a tool or the like, and complete fastening cannot be performed. For this reason, its use is limited to a mounting portion of a small electric component or the like with a small tightening load, and cannot be applied to prevention of removal of a fastening portion of a huge structure such as a steel tower, a steel pole, or a rail. Further, in the case of a bolt, since a fastener must be once disassembled in order to replace the bolt, an extremely large number of steps are required, or in some cases, the bolt cannot be replaced.

Further, when a naturally loosened fastening point is found in the maintenance inspection of a structure, it is necessary to retighten the loosened fastening point. There was a defect that could not be maintained.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a non-reversible nut capable of solving the conventional disadvantages and a spanner used for the nut.

[0007]

According to the present invention, a plurality of steps are provided on the top surface on the small diameter side of a truncated cone, and an inclined surface is formed from the top of one step to the bottom of another step. It consists of a non-reversible nut with a female thread that engages with a male thread such as a bolt on the inner circumference of the frustoconical body. It consists of a non-reversible nut which is mounted on the other nut screwed on the bolt and acts as a lock nut.

Further, in order to further firmly and securely fix the non-reversible nut to the male screw, an adhesive is interposed in a threaded portion between the male screw and the non-reversible nut. is there.

Further, the present invention makes it possible to easily and securely attach the non-reversible nut to the bolt by using a non-reversible nut spanner having an inner space having an inner surface having a surface engaged with the step of the non-reversible nut. It was fixed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention comprises a non-reversible nut 1 and a spanner 2 for screwing the nut 1 to a bolt 3. First, the structure of the non-reversible nut 1 will be described.

FIG. 1 is a perspective view of a non-reversible nut 1 of the present invention, and its structure is basically composed of a truncated cone.
Steps 5, 5 are provided at intervals on the small diameter side top surface 4, and the step 5 forms an upper step 5 a and a lower step 5 b, and the lower step 5 located at the next position from the upper step 5 a An inclined surface 6 that is inclined linearly downward toward 5b is formed.

Similarly, an inclined surface 6 is formed which is inclined linearly downward from the upper step 5a of the step 5 shown in the upper part of FIG. 1 to the lower step 5b of the step 5 at the front. Of course, the number of the step portions 5 can be increased / decreased at any time such as four, six, eight or the like, instead of two.

FIG. 3 shows a state in which the non-reversible nut 1 of the present invention is screwed to the bolt 3, and FIG. 4 shows a state in which the non-reversible nut 1 of the present invention is screwed so as to overlap the ordinary nut 7 screwed to the bolt 3. The figure also shows the use as a lock nut. Therefore, ordinary nut 7 and non-reversible nut 1
By using the double nut, the function as a lock nut is further achieved without impairing the function of tightening an extremely high load using a normal tool. For this reason, even for a huge structure that has already been assembled with ordinary bolts and nuts, without disassembling and replacing the assembly part, simply add the non-reversible nut 1 of the present invention as it is, It has made it possible to easily prevent removal. Here, the operation of the non-reversible nut 1 of the present invention will be described.

The structure of the non-reversible nut 1 according to the present invention has been described with reference to FIG.
When it is rotated in the direction, the screw 9 is screwed into the male screw of the bolt 3 to be provided at the center thereof, and the screwing is completed as shown in FIG.

On the other hand, even if the threaded non-reversible nut 1 is to be reversed with a wrench in order to remove it from the bolt, there are no protrusions or the like on the outer periphery for engaging the wrench, and the cross section is completely circular. The wrench does not engage anywhere. Further, when a force is applied to the wrench because the outer peripheral surface of the non-reversible nut 1 is conical, the wrench escapes in a small diameter direction and cannot function as a wrench.

Further, the top surface 4 is provided with a step portion 5 serving as a spanner locking portion for rotating in the P direction. With this step portion 5, only rotation in the P direction can be performed. Therefore, the nut cannot rotate in the anti-P direction, and the non-reversible nut 1 cannot be loosened.

Therefore, the non-reversible nut 1 of the present invention can be screwed with a male screw, but once screwed, it is impossible to release it at all. FIG. 4 shows a non-reversible nut 1 of the present invention screwed on a normal nut 7 attached to an object 8 to function as a stop nut and also to prevent reverse rotation.

Next, a wrench 2 for screwing the non-reversible nut 1 of the present invention into a screw, that is, a bolt 3 is as shown in FIG. Frustoconical surface and step 5 provided on the small diameter side top surface
And an internal space 10 having an inner surface having a shape engaging with the inclined surface 6 provided between the step portions 5 is provided inside the spanner 2.
The spanner 2 is fitted from above the non-reversible nut 1 and rotated in the direction of arrow P in FIG. 1 in a state where the non-reversible nut 1 and the internal space 10 of the spanner 2 are completely fitted. The vertical faces 5 and 5 are pushed by a spanner, and the non-reversible nut 1 is screwed to the screw, that is, the bolt 3. In order to obtain this effect, the wrench actually used may be a combination of the engagement function product alone shown in FIG. 2 and a normal hexagon wrench, or a wrench in which the engagement function part shown in FIG. But it is good.

Therefore, when such a screw connection is made, the tool slides on the peripheral surface of the non-reversible nut and the non-reversible nut 1 does not rotate at all, no matter what tool is used.
Cannot be removed from the male screw 3.

Further, the inclined surface 6 of the non-reversible nut 1 of the present invention may have any shape such as a straight line, a curved line, or a staircase type. .

Therefore, it should be understood that the inclined surface 6 of the present invention simply means a surface connecting the upper step 5a of one step 5 and the lower step 5b of the next step 5. Furthermore, the shape of the internal space 10 of the spanner 2 only needs to have a shape capable of pushing the step 5 of the non-rotatable nut 1 by at least the shape of the inner surface of the spanner 2.

[0022]

As described above, the non-reversible nut of the present invention is made of a single piece of a truncated cone, and therefore has a simple structure, is easy to manufacture, can be manufactured at low cost, and has no accessories, so that no failure occurs. Has advantages.

The non-reversible nut can be screwed onto the screw by simply placing a wrench having an internal space into which the non-reversible nut fits as it is over the non-reversible nut and rotating it. It is convenient because it can be screwed with a screw, and inexpensive because it can be manufactured as an integral product.

[Brief description of the drawings]

FIG. 1 is a perspective view of a non-reversible nut according to the present invention.

FIG. 2 is a partial sectional front view of a spanner for rotating a non-reversible nut according to the present invention.

FIG. 3 is a front view showing a state where a non-reversible nut of the present invention is screwed to a bolt.

FIG. 4 is a front view showing the use of the non-reversible nut of the present invention as a lock nut.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Non-reversible nut 2 Spanner 3 Male screw and bolt 4 Top surface 5 Step 5a Upper 5b Lower 6 Slope 7 Nut 9 Female thread 10 Internal space

Claims (4)

[Claims] 1. A plurality of steps are provided on the small diameter side top surface of a truncated cone, and an inclined surface is formed from an upper step of one step to a lower step of another step, and is formed on another step. Similarly, a non-reversible nut that forms a slope and has a female thread on the inner circumference of the truncated cone that engages with a male thread. 2. A non-reversible nut, wherein the non-reversible nut according to claim 1 is mounted on another nut screwed onto a bolt. 3. A non-returnable nut having an adhesive interposed between a male screw and the non-returnable nut according to claim 1 or 2 screwed thereto. 4. A wrench for a non-reversible nut having an internal space having an inner surface having a surface engaged with a step portion of the non-reversible nut according to claim 1, 2 or 3.