JP3009982B2 - Lock nut - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a locking nut which is optimal for a small and low-load fastening portion, for example, for fixing a lens of spectacles to a frame.

[0002]

2. Description of the Related Art For example, when fixing a lens to a metal member in frameless frame-type glasses, a T-shaped washer 31 made of a soft material is fitted into a mounting hole 22 of a lens 21 from both sides as shown in FIG. , Is usually assembled to the metal member 24 using a small screw 25 and a nut 32.

[0003]

However, this conventional fixing method is a method of tightening with a normal metal nut, and has a drawback that the nut does not have a locking function and the nut is loosened during use. In order to prevent this loosening, it is sufficient to tighten with a double nut or to perform a work to prevent loosening after tightening, but the appearance is bad and the cost is high. Further, in this fixing method, in order to prevent the lens from being damaged, T-shaped washers are fitted from both sides of the lens, so that the number of parts is increased, the workability of assembling is poor, and the cost is increased. The present invention has been made to solve these problems and to provide an inexpensive nut that has a locking function and does not damage the lens.

[0004]

In order to achieve this object, a threaded portion having a diameter equal to or smaller than the effective diameter of the female thread and a threaded portion thereof are provided at the rear end of a metal nut having a predetermined female thread. A locking nut in which a resin member having a screwless hole formed by a plurality of vertical grooves escaping outward is formed concentrically with and integral with the metal nut.

[0005]

[Function] Since a metal nut is inserted, the tightening strength in the axial direction is sufficiently ensured, and since the screwless hole of the resin member is smaller than the screw outer diameter, a small screw (or tapping screw) is used when tightening. As a result, a screw thread is formed, and the outer surface of the screw can be tightened by the elasticity of the resin material to prevent the screw from loosening. Also, during manufacturing,
Since a nut holding member can be used, a metal nut can be accurately inserted.

[0006]

An embodiment will be described below with reference to the drawings. FIG.
2 shows a locking nut A according to the present invention. In the figure, reference numeral 1 denotes a hexagonal nut made of metal, and a predetermined female screw 2 is formed at the center. A resin member 3 having a hexagonal outer shape extends from the rear end of the metal nut 1 and is integrally formed so as to cover the metal nut 1. The center of the resin member 3 is formed by a threaded portion 4a having the same size as the effective diameter of the female screw 2 or slightly smaller than the effective diameter, and three longitudinal grooves 4b escaping outward from the threaded portion 4a. A screwless hole 4 is formed concentrically with the metal nut 1.
Further, a bushing portion 5 extending from the resin member 3 is formed at a front end of the metal nut 1, and an inner diameter 6 of the bushing portion 5 is formed to be slightly larger than a root diameter of the female screw 2 of the metal nut 1. The nut 1 is formed integrally and concentrically. The locking nut A can be manufactured by a so-called insert molding method in which a metal nut 1 that has been processed in advance is set in a molding die and a resin material is injected. However, since a nut holding member can be provided in the vertical groove portion 4b, The metal nut 1 can be positioned at a predetermined position and held horizontally to accurately perform insert molding.

The locking nut A having this configuration is most suitable for, for example, fixing a lens of borderless glasses. As shown in FIG. 3, the bushing portion 5 of the locking nut A is inserted into the mounting hole 22 of the lens 21 to hold the resin member 3 (hexagonal outer portion), and the flat washer 23 and the metal member 24 (for example, a frame fitting). Small screw 25 inserted through
Is screwed into the female screw 2 of the nut A, and when the screwing is further continued, the tip of the small screw 25 comes into contact with the screwless hole 4 of the resin member 3 and is screwed by the small screw 25 while forming a screw thread. The resin member 3 is made of a polyacetal resin or a polyamide resin.
Since the effective diameter of the female screw 2 is substantially the same as that of the female screw 2, the screw can be easily screwed in. Further, the small screw 25 is tightened by the elastic force of the resin member 3 and the loosening of the screw can be prevented. The small screw 25 may be a tapping screw. In the case of a tapping screw, it is preferable that the diameter of the screwless hole 4 is slightly smaller than the effective diameter.

Next, FIGS. 4 to 7 show another embodiment. The locking nut B shown in FIGS. 4 and 5 has a shape in which the bushing portion 5 of the locking nut A is eliminated, and other configurations are the same. That is, it is used when the bushing portion 5 is unnecessary, and the operation effects of screwing and locking are the same as those of the locking nut A. In another embodiment shown in FIGS. 6 and 7, there is provided a locking nut C in which a fixing groove 12 is provided on the outer periphery of a metal nut 11. The effects of screwing and locking are performed by the locking nut A and the locking nut A. It is equivalent to the lock nut B. In these embodiments, the outer shape of the resin member 3 may be a two-sided cut 13 as shown in FIG. 7 or another polygonal shape, and is preferably a shape with which a tool can be engaged at the time of tightening.

[0009]

As is clear from the above description, the present invention
No screw formed at the rear end of a metal nut having a predetermined female thread formed by a threaded portion having the same diameter as or smaller than the effective diameter of the female thread and a plurality of vertical grooves escaping outward from the threaded portion. A locking nut in which a resin member having a hole is formed concentrically and integrally with the metal nut. According to the present invention, since the metal nut is inserted, the tightening strength in the axial direction is sufficiently ensured. Further, since the screwless hole of the resin member is smaller than the outer diameter of the screw, the small screw (or tapping screw) is used at the time of tightening. ) Forms a thread, so that the outer surface of the screw can be tightened by the elasticity of the resin material to prevent the screw from loosening. Further, since the conventional T-shaped washer is not required by the integrally formed bushing portion, the workability of assembling is good, the assembling cost can be reduced, and the lens is prevented from being damaged. At the time of manufacturing, the metal nut can be positioned horizontally at a predetermined position simply by using a molding die provided with a nut holding member at the position of the vertical groove, and accurate insert molding becomes possible. Numerous effects can be obtained, such as inexpensive manufacture of a locking nut.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a locking nut A of the present invention.

FIG. 2 is a bottom view of FIG.

FIG. 3 is an explanatory view showing a tightened state using a locking nut A;

FIG. 4 is a front sectional view showing a locking nut B of another embodiment.

FIG. 5 is a bottom view of FIG. 4;

FIG. 6 is a front sectional view showing a locking nut C of another embodiment.

FIG. 7 is a bottom view of FIG. 6;

FIG. 8 is an explanatory view showing a conventional tightening state.

[Explanation of symbols]

 Reference Signs List 1 metal nut 2 female screw 3 resin member 4 screwless hole 4a screw-in part 4b vertical groove part 5 bushing part 6 inner diameter A locking nut

Claims (1)

(57) [Claims] 1. A rear end of a metal nut having a predetermined female thread formed by a threaded portion having a diameter equal to or smaller than the effective diameter of the female thread and a plurality of vertical grooves escaping outward from the threaded portion. A locking nut, wherein a resin member having a formed screwless hole is formed concentrically and integrally with the metal nut.