JPS602566Y2 - Tightening device for eyeglass frames - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the tightening portion of a lens fixing screw of an eyeglass frame, particularly an eyeglass frame having a metal lens frame.

Eyeglass frames include a lens fixing part of the lens frame and a hinge for rotatably connecting the temple to the lens frame, and these are generally configured to tighten the two parts with various screws. .

In this case, the stronger the tightening force, the harder the screw will loosen, but when hanging glasses frames, various forces are applied during sushi.
The tension gradually loosens.

For example, there have been cases where the screws used to secure the lens to the lens frame have inadvertently loosened, causing the lens to fall and be damaged.

An object of the present invention is to provide a tightening device for eyeglass frames that is unlikely to loosen.

The configuration of the present invention will be explained below with reference to the drawings.

Figure 1 shows the first example in which the present invention is used in the lens fixing part of the lens frame.
It is a partial front view of the spectacle frame of an Example.

As is well known, the fixing part 1 is provided as a protruding part around a rim line 3 which is bent and formed as a lens frame for holding the lens 2.

2A and 2S are an enlarged front view and a plan view, respectively, of this lens fixing part 1, and in FIG. 2A, a part thereof is cut away.

The first blow tip 3b fixed to the upper end of the rim wire 3 and the second blow tip 3b fixed to the lower end are tightened by screws 4, and the lens 2 held by the rim wire 3 is tightened by screws 4. is fixed.

Further, a bending piece 5 for providing a temple is fixed to the first blow tip piece 3a and the rim line portion to which this bending piece 3a is fixed so as to form a three-piece unit.

FIG. 3 is a sectional view of the first blow tip 3a and the second blow tip 3b before they are tightened.

Both blow pieces are tightened in a state as shown in FIG. 5 by screws 4 as shown in FIG.

The first blow tip piece 3a is formed with a female threaded portion 31 that engages with the male threaded portion 41 of the screw 4, and the second blow tip piece 3
A blank hole portion 32 and a counterbore portion 33 having a larger diameter than the female screw portion 31 are formed in b.

The wall surface of the counterbore portion 33 is approximately a conical surface, and has a tapered shape with an inner diameter smaller than its outer diameter.

On the other hand, the head 42 of the screw 4 has a cylindrical shape, and its diameter is larger than the inner diameter of the counterbore portion 33 and smaller than the outer diameter, and the hardness of the material is greater than that of the second blow tip 3b.

Therefore, when tightening the first and second blowing pieces 3at3b with the screw 4, the head 42 of the screw 4 does not come into contact with the wall surface of the counterbore 33 at the initial stage when it is inserted into the counterbore 33; The second blow tip piece 3b is softer, so the screw 4
The head portion 42 of the broach bites into the counterbore portion 33 and a tight fit is achieved as shown in FIG. 5, completing the tightening of both broach pieces.

With this configuration, the head of the screw and the second blow tip are fitted with extremely high precision, so when the tightening force with the screw is slightly loosened, the screw may become loose when the eyeglass frame is attached or removed. Even if various eccentric forces are applied to the screw, the male threaded portion of the screw and the wall surface of the hollow hole of the second blow tip do not come into contact with each other, preventing relative displacement between the screw and the second blow tip. This prevents the loosening from increasing.

Note that even if the head of the screw does not fit completely into the counterbore,
It goes without saying that by biting in to a certain extent, an extremely good fitted state can be obtained in the same manner as above.

A second embodiment will be described in which the present invention is applied to the lens fixing portion of the lens frame in the same way as the first embodiment.

FIG. 6, FIG. 7, and FIG. 8 respectively show the first and second blow tips, screws, and screws before being tightened according to the second embodiment.
and shows the first and second blow tips tightened with screws.

In the figures, the same numbers as in the first embodiment represent the same members.

In the first embodiment, the counterbore part of the second blow tip was formed into a tapered shape and made of a material with a harder hardness than the head of the screw, but in this embodiment, the head of the screw is made of a material that is harder than the head of the screw. It was formed into a tapered shape using a material with low hardness, and the counterbore portion was formed into a cylindrical shape, and its diameter was formed to be approximately the middle of the diameter of the tapered screw head.

Also in this case, when tightening the first and second blowing pieces 3a and 3b with the screw 4, the head 42' of the screw 4 is initially inserted into the counterbore part 33'. , but does come into contact by the time the insertion into the counterbore portion 33' is completed.

After contact, since the head 42' is softer, the head 42' of the screw 4 deforms slightly following the wall surface of the counterbore 33', and the tightening of both blow tips is completed as shown in Fig. 8. .

Therefore, here as well, accurate fitting between the screw head 42' and the blank hole 33' can be achieved, and an increase in loosening can be prevented.

In the above embodiment, if one or both of the counterbore (33, 33') and the screw head (42, 42') have a Vickers hardness of 350 or less, appropriate plastic deformation will occur during tightening, and A good tight fit is achieved.

In addition, with such hardness, the taper of the conical surface formed on either the counterbore portion or the screw head is 1/2 to 1/2.
/811 degrees is more desirable.

According to the configuration of the present invention as described above, a tightening part for an eyeglass frame that is difficult to loosen even when various forces are applied when the eyeglass frame is attached or removed is provided.

Note that the present invention is effective not only for the lens fixing portion of the lens frame, but also for the hinge portion for rotatably joining the temple to the lens frame.

Further, the cross-sectional shape of the head or counterbore of the screw in the direction perpendicular to the axis of the screw does not necessarily have to be circular, and the same effect can be obtained by forming it into various polygonal shapes. Even if the hardness of the head of the screw and the counterbore are opposite to the above relationship, the objective can be achieved to some extent.

[Brief explanation of the drawing]

Figure 1 shows the first example in which the present invention is used in the lens fixing part of the lens frame.
FIG. 2a is an enlarged front view of the lens fixing part, FIG. 2 is a plan view of the lens fixing part, and FIG.
The figure is a sectional view of the first blow tip and the second blow tip before they are tightened, FIG. 4 is an enlarged view of the screw, and FIG. 5 is a cross-sectional view of the first blow tip and the second blow tip.
A state in which the blow tip piece and the second blow tip piece are tightened with screws is shown. Fig. 6 to Fig. 8 show the second embodiment, Fig. 6 shows the first and second blow pieces before being tightened, Fig. 7 shows the screws, and Fig. 8 shows the first and second blow pieces before they are tightened. 2 shows the state where the blow piece is tightened. [Explanation of symbols of main parts], 3a...First blow tip piece, 3b...Second blow tip piece, 4...
...Screw, 41...Male thread part of screw 4, 31.
...Female screw portion of first blow tip piece 3a, 32...
...Baka hole part of second blow tip piece 3b, 33...
- Counterbore part of second blow tip piece 3b, 42...Head of screw 4.

Claims (1)

[Claims for Utility Model Registration] 1. In a tightening device for eyeglass frames in which a female threaded portion is formed at one end of a lens holding frame and a counterbore portion is formed at the other end, and both are tightened with a male screw, the inner diameter of the counterbore portion and A tightening device for an eyeglass frame, characterized in that one of the outer diameters of the male screw head that is tightly fitted to the eyeglass frame is formed into a conical surface, and the materials thereof have different hardnesses. 2. In the eyeglass frame tightening device according to claim 1 of the utility model registration claim, one of the counterbore portion and the male screw head formed into a conical surface has a hardness of a material smaller than that of the other. Something that is characterized by something that has happened.