Optics: eye examining – vision testing and correcting – Spectacles and eyeglasses – Continuous rim mounting
Reexamination Certificate
1999-09-16
2001-07-03
Dang, Hung Xuan (Department: 2873)
Optics: eye examining, vision testing and correcting
Spectacles and eyeglasses
Continuous rim mounting
C351S083000
Reexamination Certificate
active
06254234
ABSTRACT:
TECHNICAL FIELD
The present invention generally relates to a front frame used for a pair of spectacles, and particularly relates to a lens holding mechanism of the front frame.
BACKGROUND ARTS
A lens used for a pair of spectacles is generally supported by a ring-shaped front frame thereof (see FIG.
1
). In case that a user wears or handles the spectacles, an external force is often exerted upon the frame or the lens. In that case, depending upon a magnitude and/or a direction of the external force thus exerted thereupon, the lens and/or the frame are/is deformed, so that the lens is often disengaged from the frame. In particular, because the spectacles used in recent years are the ones in which the lens is made of plastic and the frame is made of metal, the spectacles are liable to deformation by the external force. Therefore, the lens may be easily disengaged therefrom even by a small external force exerted thereupon. It is needless to say that such a disengagement of the lens therefrom is undesirable.
In case that the spectacles are used for protecting a user's eyeball in order to give a top priority to safety (for example, the spectacles which are used in a hazardous environment, such as a factory), a lens holding mechanism shown in
FIG. 2
is adopted. With the lens holding mechanism, the lens is never disengaged from the front frame thereof, even when some external force is exerted upon the spectacles. In this mechanism, the front frame
2
has a sectional structure with a relatively deep U-shaped groove
3
which is defined by a bottom wall
4
a,
a first side wall (wall on a side of a face)
4
b,
and a second side wall
4
c
(wall on a side opposite the face). The lens
1
has a circumferential edge having a square-shaped cross section, and the circumferential edge is fitted deep inside the U-shape groove
3
. Therefore, the circumferential edge of the lens
1
is surely held between the side walls
4
b,
4
c
on both sides of the lens
1
, and the lens is not easily disengaged from the frame even when some external force is applied thereto.
The lens holding mechanism employing the U-shaped groove type shown in
FIG. 2
is superior in safety; on the other hand, the lens holding mechanism is inferior in fashionability. The reason is that it is necessary to secure a deep engagement depth or part, for the lens, in the frame, that it is necessary to provide a structure in which the lens is supported by the both side walls from both sides of the lens, and that the front frame, therefore, can not help but become large, or thick.
In contrast with the lens holding mechanism of
FIG. 2
, a most popular lens holding mechanism having a good fashionability, in other words, having a small line diameter, is shown in FIG.
3
. In this mechanism, the front frame
2
has a sectional structure with a V-shaped groove
5
which is defined by a first inclined bottom surface (bottom surface on a side of a face)
5
a,
and a second inclined bottom surface (bottom surface on a side opposite the face)
5
b.
The lens
1
has a circumferential edge having an engagingly locking convex stripe (=“Yagen”, V-shaped ledge)
1
c
which is V-shaped in cross section and which corresponds to the sectional configuration of the frame. The engagingly locking convex stripe
1
c
is fitted into the V-shaped groove
5
with a slight play P with a state in which the engagingly locking convex stripe
1
c
roughly contacts the inclined bottom surface (refer to the circumferential edge of the lens shown in a solid line in the figure). In case that the thickness (=“koba”, edge) of the lens
1
is large (in case that the degree of the spectacles is high), the width of the V-shaped engagingly locking convex stripe
1
c
of the lens is smaller than the thickness of the lens, as shown in the figure.
According to the lens holding mechanism shown in
FIG. 3
, it has an advantage that the line diameter of the front frame can be reduced by reducing the thickness of the frame with respect to the thickness of the lens.
However, the lens holding mechanism of
FIG. 3
has such a problem that the lens is apt to become easily disengaged from the front frame when an external force is exerted thereon. An imaginary line of
FIG. 3
shows a situation in which the lens
1
is disengaged from the front frame due to an external force “F” which is exerted upon the lens
1
. Namely, it is conceivable that the lens
1
and the frame
2
are deformed by the external force “F”, that a first inclined bottom surface
1
a
of the lens
1
is easily allowed to slide over the first inclined bottom surface
5
a
defining the V-shaped groove of the front frame
2
as a result, and that the lens
1
is dropped out from the front frame
2
. Where an importance is placed on the fashionability of the spectacles, an attempt may be made to reduce the thickness of the front frame along its length and may be made to reduce the depth of the V-shaped groove thereof. As a result, the tendency of the lens falling or dropping out therefrom, will increase. However, even if the front frame is of a type of the V-shaped groove, it is possible to prevent the lens from dropping out therefrom by making the V-shaped groove sufficiently deep. Actually, many varieties of such front frames are commercially available. But where the V-shaped groove is made deeper, the line diameter of the front frame becomes thicker; accordingly, it lacks fashionability.
From a global point of view, spectacles have a very long history. Strangely enough, however, any countermeasure to prevent the lens of spectacles from falling or dropping out therefrom, particularly to prevent the lens thereof from falling or dropping out therefrom in the lens holding mechanism which is of the type of the V-shaped groove shown in
FIG. 3
, has been scarcely taken.
DISCLOSURE OF INVENTION
Therefore, it is a main object of the present invention to provide a novel lens holding mechanism, or a front frame, which effectively prevents a lens of the pair of spectacles from dropping out.
It is another object thereof to provide the lens holding mechanism, of a type of V-shaped groove, effectively preventing the lens thereof from dropping out, which is simple in construction while maintaining a fashionability of the front frame or maintaining a small linear diameter of the frame.
It is still another object thereof to provide the novel lens holding mechanism, able to effectively prevent the lens thereof from dropping out, which makes it possible to maintain a manufacturing cost of the front frame at the level substantially equal to the conventional level.
In order to achieve these technical objects, according to the present invention, there is provided a front frame for a pair of spectacles with the following construction.
That is, the front frame therefor has a V-shaped groove that engages with an engagingly locking convex stripe, having a V-shaped cross section, around a circumferential edge of a lens, and a first frictional biting-into protrusion stripe on a first inclined bottom surface defining the V-shaped groove, wherein the first frictional biting-into protrusion stripe extends in a direction in which the front frame extends, and wherein the first frictional biting-into protrusion stripe contacts a part of a first inclination bottom surface of the engagingly locking convex stripe of the lens. Preferably, the first inclined bottom surface of the V-shaped groove is on a side of a face of a wearer or user who puts on the pair of spectacles. Each of the inclination bottom surface of the engagingly locking convex stripe having the V-shaped cross section and the inclined bottom surface of the V-shaped groove, includes a case in which it is a flat surface, and includes a case in which it is a roundly curving surface.
In the aforementioned construction, a lower part of the engagingly locking convex stripe having the V-shaped cross section of the lens, contacts the front frame near the lowermost part of the V-shaped groove; and a part of the first inclination bottom surface of the engagingly locki
Burns Doane , Swecker, Mathis LLP
Dang Hung Xuan
Utsumi Optical Products, Inc.
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