EYEGLASS WITHOUT HINGE ASSEMBLY AND USING SHAPE-MEMORY ALLOY
FIELD OF THE INVENTION
The present invention relates to an eyeglass having eyeglass legs made of a shape-memory alloy. Particularly the present invention relates to an eyeglass without hinge assembly and using a shape-memory alloy, in which the eyeglass legs can be folded in spite of the lack of the hinge assembly.
BACKGROUND OF THE INVENTION
Generally, an eyeglass has to be good in its wear feeling, and it has to be light. If the wear feeling is to be good, the eyeglass legs have to suit to the curve of the face. Thus, the eyeglass should not oppress the side of the face, and should not drop down, while the eyeglass has to be properly tight to the face.
Among the above cited requisites, if the eyeglass legs are not to oppress the sides of the face, then the eyeglass legs should not contact to the face. However, if the eyeglass is not to be dropped down, then the eyeglass legs have to contact to the face as much as possible.
Thus the reduction of the oppression of the eyeglass legs on the face and the prevention of the dropdown of the eyeglass require different shapes of the eyeglass legs. That is, if the eyeglass legs are not to oppress the face, then the eyeglass legs have to be separated from the face as far as possible.
Accordingly, the eyeglass legs have to be much spreadable. On the other hand, if the eyeglass legs are not to be dropped down along the face, then the eyeglass legs have to contact to the face as close as possible, and therefore, the eyeglass legs have to be less spreadable.
Accordingly, the two opposite functions require different structures of the eyeglass legs.
In the most of the general eyeglasses, one kind of legs cannot satisfy the two opposite functions, and therefore, in most cases, the gap between the two legs is properly adjusted, so that the wear feeling and the contact force can be simultaneously obtained. However, an accurate adjustment of the gap between the two eyeglass legs is difficult, and not only so, but if the eyeglass is used for a long time, the gap between the two eyeglass legs is widened. Accordingly, most people endure the inconvenience due to the un fitness of the eyeglass.
As an attempt to solve this problem, there are the eyeglasses in which the legs are made of a super-elastic shape-memory alloy. However, these eyeglasses still have various problems as described below.
First, the general eyeglass legs are shaped straight, but in the case where the shape-memory alloy is used, its super-elasticity is utilized. Thus in order to make the eyeglass legs fit to the face, the eyeglass legs are made outwardly convex. In this case, however, hinges are required so that the eyeglass legs can be folded.
Therefore, after taking off the eyeglass, the legs have to be folded around the hinges, while to put on the eyeglass, the legs have to be unfolded, this being troublesome. Thus in spite of the fact that the super-elastic shape-memory alloy is used, the eyeglass lens and the eyeglass leg are connected through the hinge together, and therefore, the super-elasticity of the shape-memory alloy cannot be fully utilized.
Meanwhile, as described above, the hinge assembly is used on the eyeglass leg, and therefore, the troublesomeness is same even in the case where the shape-memory alloy is used, as in the case of the general eyeglasses.
Second, in the case where the whole eyeglass leg is made of the shape-memory alloy, any deformation is difficult, and therefore, the fitting work becomes impossible. The fitting work refers to the operation of fitting the angle of the rear part of the eyeglass leg, i.e., the ear-engaging part of the eyeglass leg to the contour of the face by bending it downward.
Accordingly, although the eyeglass leg made of the shape-memory alloy can be made to contact to the side of the face with a proper oppressing force, the ear-engaging part of the leg is not really accurately engaged to the ear compared with the general eyeglass, this being an inconvenience. Further, the hinge means which connects the eyeglass leg to the eyeglass lens and makes it possible to fold the leg may become loose or may be deprived of the screw depending on the user, thereby causing a disorder. Meanwhile, in some cases, the nose leg which connects the two lenses together and settles the eyeglass on the nose is also made of the shape-memory alloy so as to utilize the super-elasticity, thereby improving the wear feeling. In this case also, the nose leg cannot be adjusted properly to the nose contour.
Further, the eyeglasses in which the legs are made of the shape-memory alloy or the general metals are heavy due to the weight of the legs and the hinge, and therefore, they are burdensome on the nose.
SUMMARY OF THE INVENTION
The present invention is intended to overcome the above described disadvantages of the conventional techniques. Therefore it is an object of the present invention to provide a light eyeglass in which the hinge assembly is eliminated, but the eyeglass legs can be folded and unfolded in a simple manner, thereby making the wearer of the eyeglass comfortable.
It is another object of the present invention to provide an eyeglass in which the eyeglass legs are automatically folded even if any folding action is not taken.
It is still another object of the invention to provide an eyeglass in which the nose leg is made of a shape-memory alloy, but the curve angles of the ear-engaging part of the eyeglass legs and the curve angle of the nose leg can be fitted to the contours of the ears and that of the nose.
In achieving the above objects, in the eyeglass with two legs connected to two non-framed lenses respectively directly, the legs being
made of a shape-memory alloy, according to the present invention, each of the legs includes: a hook-shaped leading end engaging part, with its one end being fastened directly to the lens by using a screw; an arcuate elastic bent part extending from the hook-shaped leading end engaging part and capable of being freely bent and unbent so as to play a role of a hinge; and a straight ear-engaging part with a straight shape for being engaged on an ear.
The eyeglass according to the present invention further includes: a nose leg with a pair of nose pads installed thereon and being made of the shape-memory alloy. The nose leg includes: a horizontal part for connecting the two lenses together; two vertical parts; and a rectangular bent part given a de-memorizing treatment.
In another aspect of the present invention, the ear-engaging part of the eyeglass leg is given a de-memorizing treatment so that the leg can be unfolded or contracted (deformed), thereby making the length of the leg fit to the facial structure.
In the eyeglass of the present invention, the eyeglass legs tend to be folded inward all the time because of the elastic bent part (which is made of the shape-memory alloy). Accordingly, when the eyeglass is taken off, the legs are automatically folded even if any folding action is not taken. When the eyeglass is to be put on, the eyeglass legs can be unfolded in a simple manner owing to the elastic bent part.
Accordingly, putting-on and taking-off the eyeglass are extremely convenient, and the eyeglass legs tend to be folded inward all the time. Therefore, when the eyeglass is put on, the eyeglass legs are contacted on the wearer's face with a proper elastic force, thereby giving a comfortable wear feeling. Further, the eyeglass legs are extremely light, and therefore, the eyeglass itself becomes light.
Further, any hinge assemblies are eliminated from the eyeglass legs, and therefore, any disorders of the hinge assemblies are excluded at the same time. Further, the wear feeling can be prevented from being aggravated.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects and other advantages of the present invention will become more apparent by describing in detail the preferred embodiment of the present invention with reference to the attached drawings in which:
FIG. 1 is a perspective view of the hingeless eyeglass using a shape-memory alloy according to the present invention;
FIG. 2 is a perspective view of the eyeglass leg of the eyeglass according to the present invention; FIG. 3 is an enlarged sectional view taken along a line A-A of FIG. 2;
FIG. 4 is an enlarged sectional view taken along a line B-B of FIG. 2;
FIG. 5 schematically illustrates a jig for forming the eyeglass leg according to the present invention; and
FIG. 6 is a perspective view of the nose leg according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Now the present mvention will be described in detail referring to the attached drawings. FIG. 1 is a perspective view of the eyeglass without a hinge assembly and using a shape-memory alloy according to the present invention. Here, the eyeglass is folded up.
As shown in this drawing, each of two eyeglass legs 2 is connected to the outer side of each of two lenses 1, and the eyeglass is frameless. Further, a nose leg 3 of the usual type is installed between the two lenses 1.
The eyeglass legs 2 are made of a shape-memory alloy, and each of the legs 2 includes: a hook-shaped leading end engaging part 4, with its one end being fastened directly to the lens 1 by using a screw; an arcuate elastic bent part 5 extending from the hook-shaped leading end engaging part 4 and capable of being freely bent and unbent so as to play a role of a hinge; and a straight ear-engaging part 6 with a straight shape for being engaged
on an ear.
Meanwhile, as shown in FIG. 3, the elastic bent part 5 has a rectangular cross section, and the ear-engaging part 6 preferably has a round cross section as shown in FIG. 4. The reason is as follows. That is, if the cross section is so, when the eyeglass is unfolded from the folded state as shown by the dotted lines in FIG. 1, the elastic bent part 5 can be deformed to a more gentle curve smoothly without any concentration of stress on a particular portion.
Further, as shown in FIG. 4, the ear-engaging part 6 should preferably have a round cross section, and the reason is as follows. That is, the ear-engaging part 6 is a part not to be deformed unlike the elastic bent part 5, and therefore, the ear-engaging part 6 has to have a certain rigidity. Of course, the cross section of the ear-engaging part 6 may not be necessarily round, but may be of other shape. In order to make the elastic bent part 5 optimally elastic, the width of the elastic bent part 5 should be preferably 20 ~ 80 % of the width of the ear-engaging part 6. The reason is as follows. That is, the elastic bent part 5 is made by using the stock same as that of the ear-engaging part 6 but by applying a mechanical process such as rolling or the like. The material of the shape-memory alloy for the eyeglass legs of the present invention may the usual ones. The examples include: β -Ti, Inno-Ti, NiTi alloy, and NiTi added with Co, Cr, Cu, V, Mo, Mn or Fe.
The eyeglass leg which is made of the shape-memory alloy and have the leading end engaging part 4 and the elastic bent part 5 and the ear-engaging part 6 can be formed at a jig 7 by carrying out a heat treatment as shown in FIG. 5. The jig 7 includes: a groove 8 for forming the leading end part 4; a gently curved part 9 for forming the elastic bent part 5; and a straight part 10 for forming the straight ear-engaging part 6.
The radius of curvature for the gently curved part 9 is varied depending on the facial structure of the wearer, but roughly is about 5
20mm.
If the leg is coupled to the above described jig 7, and if a heat
treatment is carried out, then the final eyeglass leg of the present invention can be obtained.
To present an example of the heat treatment for making the leg 2, if a heat treatment is carried out at a temperature of 280 ~ 500 °C for 10 — 70 minutes, then the shape-memory is formed in the eyeglass legs, thereby making it possible to eliminate the hinge assembly.
As shown in FIG. 1, in the eyeglass leg 2 which has been formed in the above described manner, its leading end engaging part 4 is fastened to a hole of the lens 1 by using a screw 11, the fastening being thus simple. The eyeglass leg 2 according to the present invention, which is fastened to the lens 1, is made of the shape-memory alloy, and its elastic bent part 5 has a rectangular cross section, so that it can be freely unfolded to a rectangular shape as shown by the dotted lines in FIG. 1. When the legs are spread, if the external force is withdrawn, then the legs are immediately restored to the arcuate shape.
Accordingly, in the eyeglass having the legs of the present invention, when the eyeglass is taken off, even if no action is taken, the eyeglass legs are automatically folded.
Further, the eyeglass legs of the present invention are made of a shape-memory alloy without a permanent deformation and with a good elasticity, and therefore, their cross sectional areas can be reduced. Accordingly, the eyeglass legs can be made light in their weight, and consequently, the entire eyeglass is reduced in its weight.
Meanwhile, only the ear-engaging part 6 of the eyeglass leg 2 may be given a de-memorizing treatment so as to improve its effectiveness. For example, if this de-memorizing treatment is done on the ear-engaging part 6, then it can be arbitrarily deformed, and thus, the angle of the ear-engaging part 6 can be deformed suitably to the contour of the face, as well as adjusting the length of the leg within a proper range. The nose leg 3 which is installed between the two lenses 1 is also made of the shape-memory alloy, and its structure is as follows. That is, as shown in FIG. 6, the nose leg 3 directly connects the two lenses 1 together,
and includes: a horizontal part 12; a pair of vertical parts 14 with a pair of nose pads 13 installed thereon; and a bent part 15. Only the bent part 15 which connects the horizontal part 12 and the vertical parts 14 together is given a de-memorizing treatment. Accordingly, although the nose leg 3 is made of the shape-memory alloy, the bent part 15 can be deformed so that the vertical parts 14 can be arbitrarily bent suitably to the facial contour, thereby providing a comfortable wear feeling.
One example for de-memorizing the ear-engaging part 6 of the leg and the bent part 15 of the nose leg 3 will be presented. That is, a heat treatment is carried out at a temperature of 600 ~ 800 V for about 5 ~ 30 minutes, and then, a water quenching is carried out. In this manner, the shape memory is eliminated.
Through this heat treatment, the ear-engaging part 6 of the leg 2 and the bent part 15 of the nose leg 3 are de-memorized. Thus the eyeglass legs 2 and the nose leg 3 which are made of the shape-memory alloy can be arbitrarily adjusted suitably to the facial structure, thereby ensuring a comfortable wear feeling.
According to the non-hinged eyeglass of the present invention as described above, the eyeglass legs are directly connected to the eyeglass lenses, and its elastic bent part has a thin rectangular cross section together with a high flexibility. Therefore, the legs can be arbitrarily unfolded, and are automatically folded when the eyeglass is taken off. Further, the eyeglass legs tend to be folded inward all the time owing to the elastic bent part, and the mass of the eyeglass legs is not large. Therefore, the discomfort of the conventional eyeglasses is eliminated, but the eyeglass does not drop down along the face.
Further, a part of the leg and a part of the nose leg are given a de-memorizing treatment, and therefore, the eyeglass can be fitted to the facial contour. Accordingly, the wear feeling becomes excellent, and the manufacturing process is simplified.