Eyeglass connection device

Sunglasses include a lens which is replaceable with an alternative one at any time, and provides such sunglasses in which frames thereof can be easily attached to and detached from the lens, and the frames can be held stably on the lens while attached thereto, and which provide a user with a good wear feeling. The sunglasses of the present invention include a lens, frames detachably mounted on the respective mounting portions of the lens; and temples attached to the respective frames. When the frames are mounted on the respective mounting portions, holding pieces of each of the frames hold therebetween the corresponding mounting portion, while an elongated protrusion and projection of each of the frames are engaged with an engagement long nick or slot and an engagement hole in the lens, respectively.

TECHNICAL FIELD 
The present invention relates to sunglasses being provided with a lens of 
the single-lens type. 
BACKGROUND ART 
Recent years have seen, especially on the occasion of the playing sports, 
the frequent use of sunglasses having: a lens of single-lens type made of 
a plastic resin such as polycarbonate, frames mounted on both side edges 
of the lens, and temples attached to the respective frames. With some of 
these sunglasses, a user can selectively change parts such as lenses or 
frames in order to coordinate their colors and designs suitably for 
occasions and purposes. 
FIG. 12 shows a typical mounting structure of frames and a lens adopted in 
such sunglasses. Opposite upper side edges of a lens 2 of sunglasses 1 are 
provided with their respective mounting elements 3 each having its tip 
portion 3a formed into a hook. Each of a pair of frames 4 is in the form a 
U-shaped flume with its opening facing downward. A temple 5 is attached to 
one end in the longitudinal direction of each of the frames 4 and 
pivotally supported thereby. At the midpoint of each of the frames 4 is 
provided an engagement piece 6 so that it is held between the opposed 
inner walls of the corresponding frame 4. Each of the mounting elements 3 
is inserted into the frame 4 from the side of the other end in the 
longitudinal direction of the frame 4, so that the above tip portion 3a 
comes to mesh with the engagement piece 6. 
In the sunglasses 1 with such a mounting structure, although the frames 4 
can easily be mounted on or dismounted from the lens 2 (by so-called 
one-touch operation), if the tip portion 3a is accidentally disengaged 
from the engagement piece 6, the mounting element 3 of the lens 2 slips 
down through the downside opening of the frame 4. In short, the frames 4 
easily come off the lens 2 by accident, which presents a problem to be 
solved. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide sunglasses with enhanced 
usability in which frames can easily be mounted on and dismounted from a 
lens, while they are less likely to come off the lens by accident. 
The present invention includes a lens of the single-lens type made of a 
plastic resin, a pair of frames mounted on opposite upper side edges of 
the lens, and a pair of temples pivotally supported by the pair of 
respective frames. Each of the upper side edges of the above lens is 
provided with an engagement hole and an engagement long nick substantially 
horizontally extending and having an open outer end. Each of the above 
frames is provided with a pair of holding pieces for holding therebetween 
one of the upper side edges of the lens. An inner face of either one of 
the holding pieces is provided with a projection to be engaged with the 
above engagement hole. An elongated protrusion is provided between the 
holding pieces so as to be engaged with the above engagement long nick. 
According to the present invention, in mounting a frame on the lens, one of 
the upper side edges of the lens is inserted into the space between the 
holding pieces of the frame, while the elongated protrusion of the frame 
is engaged with the corresponding engagement long nick of the lens, 
thereby moving the frame toward the interior of the lens and engaging the 
projection of the frame in the corresponding engagement hole of the lens. 
Consequently, the holding pieces of the frame hold therebetween the side 
edge of the lens, while having the elongated protrusion of the frame 
engage with the engagement long nick of the lens, and having the 
projection of the frame engage in the engagement hole of the lens. As a 
result, the shifting of the frame both toward the interior of the lens and 
in the vertical direction of the lens is restrained, so that the frame is 
stably held on the lens. 
In dismounting the frame from the lens, on the other hand, the projection 
is pulled out of the engagement hole by pushing apart the holding pieces 
and then the elongated protrusion is pulled out of the engagement long 
nick, while the frame is moved toward the exterior of the lens, thereby 
dismounting the frame from the lens. 
The projection is advantageously formed into a substantially hemispherical 
configuration. According to the present invention, the operation of 
fitting the projection into the engagement hole and the operation of 
pulling the projection out of the engagement hole can be performed easily 
without damaging the lens. 
The sunglasses are advantageously constituted such that the elongated 
protrusion extends with the tip thereof reaching about the midpoint of 
each of the holding pieces and that the projection is provided in a 
position slightly closer to the free ends of the holding pieces than to 
the above tip. According to the present invention, an undesired shift of 
the entire frame is restrained so that the frame is held securely on the 
lens. Moreover, since the free ends of the holding pieces are provided 
with no elongated protrusion and no projection, the side edge of the lens 
is smoothly inserted into the space between the holding pieces in mounting 
the frame on the lens. Furthermore, even if the free ends of the holding 
pieces are pushed apart for any undesired reason, the projection is less 
likely to come off the engagement hole simultaneously. 
The projection is preferably provided in a position deviated from the 
extension line of the elongated protrusion. According to the present 
invention, even if the projection is accidentally disengaged from the 
engagement hole, the projection is less likely to come off the engagement 
long nick simultaneously. 
Vent holes are advantageously formed in the respective base ends of the 
temples along the length of the temples. According to the present 
invention, the sunglasses are excellent in ventilation and produce a 
feeling of comfortableness when worn by a user. 
The sunglasses are advantageously constituted such that the respective free 
ends of the temples are detachably provided with non-slip covers made of 
an elastic material with long holes formed in the outer sides thereof 
along the length of the temples, and that the free ends of the temples are 
formed with elongated protrusions, which are fitted into the corresponding 
long holes and become substantially flush with the outer faces of the 
covers when the covers are attached thereto. According to the present 
invention, the non-slip covers provided on the free ends of the temples 
prevent the falling of the sunglasses while they are worn. In addition, 
the long holes formed in the respective outer sides of the covers enable 
easy attachment and detachment of the covers and prevent the accidental 
shifting and coming off of the covers. Further scope of applicability of 
the present invention will become apparent from the detailed description 
given hereinafter. However, it should be understood that the detailed 
description and specific examples, while indicating preferred embodiments 
of the invention, are given by way of illustration only, since various 
changes and modifications within the spirit and scope for the invention 
will become apparent to those skilled in the art from this detailed 
description.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
As shown in FIG. 1, sunglasses 11 include a lens 12; a pair of right and 
left frames 13; and a pair of right and left temples 14. The lens 12 is 
composed of a single plate lens made of a translucent plastic material, 
such as polycarbonate, and is slightly warped so as to fit the facial 
configuration of a user. The upper edge of the lens 12 is formed 
substantially horizontal. The lower central portion in the longitudinal 
direction of the lens 12 is formed with a V-shaped notch. If required, an 
inner frame 15 separately formed from a plastic resin or rubber is mounted 
around the central portion of the lens 12. 
Opposite side edges of the lens 12 are also formed with their respective 
V-shaped notches. The projecting portions above the respective notches are 
intended to serve as mounting elements 16 on which frames 13 are to be 
mounted. The frames 13 will be described later. 
At about the midpoint in the vertical direction of each of the mounting 
elements 16 is provided an engagement long nick or slot 17 extending 
substantially horizontally and having an open end at the corresponding 
side edge. The mounting element 16 is also provided with a substantially 
circular engagement hole 18 in a position interior to the tip 17a of the 
engagement long nick 17 and slightly above the extension line of the 
engagement long nick 17. 
The frame 13 is made of an elastic material such as a synthetic resin. FIG. 
2(A) shows the frame 13 when viewed from the direction indicated by the 
arrow X1 in FIG. 1 (i.e., from the side of the user's face wearing the 
sunglasses). FIG. 2(B) shows the frame 13 when viewed from above. FIG. 
2(C) is a cross section taken along the center line in the direction of 
the thickness of the frame 13 in FIG. 2(B). 
The frame 13 includes a base 21; a pair of holding pieces 22 and 23 which 
protrude side-by-side from the respective ends in the direction of the 
thickness of the base 21 toward the interior of the lens (downstream of 
the arrow X2); and a temple attachment piece 24 projecting outwardly from 
the base 21. Each of the holding pieces 22 and 23 presents a substantially 
triangular configuration in which the lower-edge profile is slightly 
inclined downward from the above base 21 and then upward. 
At the midpoint between the both ends in the direction of the thickness of 
the above base 21 is provided an elongated protrusion 25 which is 
projecting into the space between the holding pieces 22 and 23. The length 
of the elongated protrusion 25 is determined such that the tip 25a thereof 
reaches about the midpoint of each of the holding members 22 and 23. The 
holding piece 23 positioned exterior to the lens (upstream of the arrow 
X2) is formed with a substantially hemispherical projection 26 which is 
projecting toward the other holding piece 22. The projection 26 is 
provided in a position slightly above the extension line of the elongated 
protrusion 25 and slightly closer to the interior of the lens than to the 
above tip 25a. 
In mounting the frame 13 on the lens 12, the frame 3 is moved toward the 
interior of the lens, while the mounting element 16 is held between the 
holding pieces 22 and 3. In the process, the elongated protrusion 25 is 
slid along the inner face of the engagement long nick 17 until the tip 25a 
of the elongated protrusion 25 reaches the innermost end 17a of the 
engagement long nick 17, thereby engaging the elongated protrusion 25 in 
the engagement long nick 17, while fitting the projection 26 into the 
engagement hole 18. At this stage, the upper edge of the mounting element 
16 of the lens 12 is substantially flush with the upper edge of the frame 
13. 
The lens 12 on which the frame 13 has been mounted is shown in FIG. 3. 
FIGS. 4A-4C are cross sections taken along the respective lines of FIG. 3, 
of which: FIG. 4(A) is a cross section taken along the line 4A--4A; FIG. 
4B is a cross section taken along the line 4B--4B; and FIG. 4(C) is a 
cross section taken along the line 4C--4C. 
In dismounting the frame 13 from the lens 12, on the other hand, the free 
ends of the holding pieces 22 and 23 are initially pushed wide apart 
against the elasticity of the holding pieces, thereby disengaging the 
projection 26 from the engagement hole 18. At this stage, the frame 13 is 
moved toward the exterior of the lens, thereby pulling the elongated 
protrusion 25 out of the engagement long nick 17. 
In this manner, the mounting and dismounting of the frame 13 can be 
performed by so-called simple one-touch operation, which enables the user 
to change lenses and frames at his pleasure. 
In addition, once the frame 13 has been mounted on the lens 12, it can be 
held stably on the lens 12. Specifically, the holding pieces 22 and 23 
hold therebetween the mounting element 16, while the elongated protrusion 
25 is engaged in the engagement long nick 17, thereby preventing the frame 
13 from shifting in the vertical direction with respect to the lens 12. 
Moreover, since the projection 26 is engaged with the engagement hole 18, 
the frame 13 is prevented from shifting toward the exterior of the lens as 
well as in the vertical direction. Consequently, the frame 13 is less 
likely to be displaced or let fall from the mounting element 16 by the 
movement of the user or the like. 
Furthermore, since such a mounting structure of the lens 12 and the frame 
13 can easily be implemented by providing the mounting element 16 with the 
engagement hole 18 and elongated protrusion 17 and using the frame 13 
integrally formed with the elongated protrusion 25 and projection 26, it 
is also advantageous in improving the efficiency of the manufacturing 
process. 
With the above projection 26 formed into a substantially hemispherical 
configuration, the engagement and disengagement in and from the engagement 
hole 18 is easily carried out and hence the frame 13 can be mounted and 
dismounted on and from the lens 12 more smoothly. Moreover, the 
possibility of the lens 12 being damaged by the projection 26 in mounting 
and dismounting the frame 13 on and from the lens 12 is small. 
Furthermore, the projection 26 in a substantially hemispherical 
configuration is also advantageous in forming the frame because of the 
ease with which the resulting frame is withdrawn from its pattern. 
Since the elongated protrusion 25 is provided not only from the vicinity of 
the base 21 but extensively from the base 21 to about the midpoint of each 
of the holding pieces 22 and 23, and the projection 26 is also provided in 
the vicinity of the midpoint of each of the holding pieces 22 and 23, once 
the frame 13 has been mounted on the lens 12, an undesired shift of the 
entire frame 13 is surely prevented. Moreover, since no elongated 
protrusion and no projection is provided in the vicinity of the free ends 
of the holding pieces 22 and 23, the mounting portion 16 can be smoothly 
inserted into the space between the holding pieces in mounting the frame 
13 on the lens 12. Furthermore, the possibility of damaging the lens 12 is 
also small. 
Since the projection 26 is provided in a position deviated from the 
extension line of the elongated protrusion 25, even when the projection 26 
slips off the engagement hole 18, the possibility that the elongated 
protrusion 25 simultaneously comes off the engagement long nick 17 is 
small. Moreover, since the projection 26 is provided in the upper part of 
the holding piece, the operations of engaging and disengaging the 
projection 26 in and from the engagement hole 18 are easily performed. 
If required, the structure of the frame 13 and mounting element 16 can be 
changed appropriately in the present embodiment. Hence, the configuration 
of the frame 13 can be varied in accordance with the configuration of the 
mounting element 16. If required, the configuration of the elongated 
protrusion 25 can also be changed appropriately. For example, the 
elongated protrusion 25 may have a length reaching the vicinity of the 
free ends of the holding pieces, as shown in FIG. 6(A). Alternatively, the 
elongated protrusion 25 may have a length not reaching the midpoint of 
each of the holding pieces, as shown in FIG. 6(B). Alternatively, the 
elongated protrusion 25 may be tapered, as shown in FIG. 6(B). 
Alternatively, a plurality of elongated protrusions 25 may be provided, as 
shown in FIG. 6(C). In either case, the engagement long nick 17 is so 
configurated as to mesh with the elongated protrusion 25. The respective 
positions of the elongated protrusion 25 and engagement long nick 17 can 
also be changed, provided that they correspond to each other. 
If required, the configuration of the projection 26 can be changed 
appropriately. For example, the projection 26 may be shaped into a 
cylinder, as shown in FIG. 7(A), or into a prism, as shown in FIG. 7(B). 
In either case, the engagement hole 18 is so configurated as to mesh with 
the projection 26. The respective positions of the projection 26 and 
engagement hole 18 can also be changed, provided that they correspond to 
each other. By way of example, FIGS. 8(A) and 8(B) show the case where the 
position in which the projection 26 is to be provided is not restricted so 
long as the projection 26 is provided on either one of the opposed faces 
of the holding pieces. Alternatively, a plurality of projections 26 may be 
provided, as shown in FIG. 8(C). 
To the frame 13 so constituted as to be mounted on the lens 12 described 
above is attached a temple 14, which is shown in FIG. 9. A cross section 
taken along the line 10--10 of FIG. 9 is shown in FIG. 10. The temple 14 
comprises: a base 31; a frame attachment element 32; and a non-slip cover 
33. The base 31 is composed of a rod which may be made of a synthetic 
resin and formed with an oblique step 31c in the vicinity of the center 
thereof. The base 31 is formed such that its portion positioned between 
one end 31a and the step 31c becomes slightly thicker than its portion 
positioned between the step 31c and the other end 31b. Between the step 
31c and the other end 31b is formed an elongated protrusion 34 on one side 
face of the base 31. 
The frame attachment element 32 may consists of, a pair of metal rods 32a 
and 32b. The respective ends of the rods 32a and 32b hold the above 
attachment element 24 from above and from below, respectively. The rods 
32a and 32b are rotatably attached to the attachment element 24 by means 
of a fitting part 35 such as a hinge. The respective other ends of the 
rods 32a and 32b are fixed to the above one end 31a of the base 31 by for 
example an insert formation, thereby forming a vent hole 36 between the 
rods 32a and 32b. 
Thus, with the vent hole 36 provided at least in the vicinity of the base 
end of the temple 14, ventilation around the user's face is improved, 
which considerably enhances the usability of the sunglasses 11. 
The cover 33 is formed from an elastic material and, more preferably, it is 
formed from rubber. The cover 33 covers up the portion positioned between 
the step 31c and the other end 31b of the above base 31. One side face of 
the cover 33 is formed with a long hole 37 into which the elongated 
protrusion 34 is to be fitted. Consequently, in the operation of attaching 
the cover 33 to the base 31, the base 31 is fitted into the cover 33 more 
easily by elastically expanding the long hole 37. Once the cover 33 has 
been attached to the base, it is less likely to come off by accident, 
since the long hole 37 is engaged with the elongated protrusion 34. In 
addition, the elongated protrusion 34 appearing in a single line on one 
side face of the cover 33 is also advantageous in terms of design. 
Preferably, the height of the elongated protrusion 34 and the thickness of 
the cover 33 are substantially equal in dimension such that the cover 33 
attached to the base 31 becomes substantially flush with the elongated 
protrusion 34. It is also preferable that the step 31c of the base 31 is 
flush with the cover 33. 
The vent hole 36 is not limited to the embodiment described above. For 
example, the vicinity of the base end of the temple 14 may be formed with 
a single vent hole 36 or a plurality of vent holes 36 in a given 
configuration, as shown in FIG. 11. 
As described above, according to the present invention, frames can easily 
be attached to and detached from a lens. Moreover, once the frames have 
been attached to the lens, they can be held stably on the lens without 
being displaced or slipping off the lens. Furthermore, the sunglasses of 
the present invention are excellent in ventilation when worn by a user, 
while they are prevented from slipping down by the covers which can be 
easily attached thereto and detached therefrom. Therefore, the usability 
of the sunglasses are remarkably enhanced. 
The present invention provides sunglasses which allow the lens thereof to 
be changed at any time and the frame thereof to be easily mounted and 
dismounted on and from the lens. Once the frame has been mounted on the 
lens, the frame can be held stably on the lens, resulting in sunglasses 
with enhanced ventilation and usability. 
The invention being thus described, it will be obvious that the same may be 
varied in many ways. Such variations are not to be regarded as a departure 
from the spirit and scope of the invention, and all such modifications as 
would be obvious to one skilled in the art are intended to be included 
within the scope of the following claims.