Frames for the same.
Year: 1885

page_text: .
Frames for the same.
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I, JACOB PILISCHER, of 88 New Bond Street, in the County of Middlesex,
Optician, do hereby declare the nature of said invention for IMPROVEMENTS IN
LENSES FOR SPECTACLES AND EYE GLASSES, AND IN FRAMES FOR THE SAME," and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement, reference being had to the accom-
panying drawings and to the letters and figures marked thereon, that is to say :-
Heretofore in spectacles or eye glasses combining half or segmental lenses of
different powers or characters, it has been usual to make such lenses either of two
distinct half lenses, with the line of junction horizontally; or with lenses in which
the different focii have been worked or ground upon the same piece of glass, in a
curvilinear direction, and in which the lowest point of the curve is in the centre of
the lens; but in both these systems, serious defects have presented themselves.
the first case the horizontal line of junction coming directly between the half
lenses has interfered considerably with the line or field of vision; and in the other
case, the luminous rays falling on the imaginary line of junction, between the
different lenses, have converted these lenses into a prism, thereby seriously
interfering with, and in many cases injuring the vision.
In
Now, the object of my Invention is to remedy these evils, and to so construct
and arrange combined lenses for spectacles and. eye glasses in such manner that the
line of vision or focial axis shall not, in any way, interfere with the sight, and so
that the same instrument may be used for reading, walking, and general purposes.
My Invention will be readily understood on reference to the accompanying
drawings, in which fig. 1 is an elevation, and fig. a section of a pair of spectacles,
embodying my invention.
According to my Invention, I make up each of the glasses of two segmental
lenses A, A, of different powers or characters, according to the sight of the person
to which they are destined, the junction of the two lenses being, in some cases,
effected by causing the said lenses to lie or fit upon or against the other, and in
other cases; in a frame specially contrived for their reception. The line of junction
of the lenses is, for the purposes of my Invention, of curvilinear form, as shewn
at a, so as not to interfere with the line or field of vision, which it would otherwise

page_text: do if it passed through the field of the lenses in a horizontal plane, or if both
powers were worked upon one glass, as in the old system. This curved line of
junction, therefore, forms an important feature in my Invention.
The smaller lenses A*, A* may, if preferred, be arranged above the larger
lenses A, A, or the lenses may be of equal sizes, according to the requirements of
the case.
To prevent the light striking against the curved line of junction and converting
the lenses into a prism, the meeting edges of the lenses may be blackened; or
instead of blackening them, I may introduce between the edges of the lenses, a thin
strip of ebonite, tortoise shell, metal, or other opaque material, and, if preferred, the
wire strip may be formed in a piece with the " eyes or frame of the instrument.
This last arrangement is shewn at fig. 3, in which b, is the wire strip.
"
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim, is
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•
1. Constructing and arranging segmental lenses for spectacles and eye glasses in
the manner herein described, that is to say, with the line of junction of said
segmental lenses curved, substantially as and for the purposes specified.
2. In combination with the segmental lenses described, the employment of a
strip of opaque material inserted between the curved edges of said lenses at their
line of junction, for the purposes specified.
3. The construction of frame with curvilinear "eyes," as herein described and
shewn.