Year: 1887

page_text: I WILLIAM PHILLIPS THOMPSON F.C.S. M.I.M.E. of the Agency for Foreign Patcut
Solicitors, 6 Lord Street Liverpool, and 6, Bank Street Manchester both in the County
of Lancaster and 323 High Holborn in the County of Middlesex Civil Engineer, do
hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
This invention relates to that class of eye-glasses in which the two glasses or lenses
are united by a spring.
The aim of the invention is to permit the folding or closing of the glasses without
subjecting the spring to increased tension as usual, and this for the double purpose
of avoiding breakage and of preventing the tension of the spring from becoming
changed.
It consists essentially in providing the connecting spring with a joint the pivot of
which stands in a horizontal position, so that the glasses may be folded together in a
plane parallel with their faces. The joint may be variously constructed, and the
spring portion connected thereto in any appropriate manner which will admit of the
glasses being folded in the manner described.
In the accompanying drawings:-
Figure 1, is a perspective view of a pair of glasses having the improvement
incorporated therein.
Figure 2, is a face view of said glasses in a closed condition.
Referring to the drawings
A A represent the two glasses or lenses, and B the connecting spring attached at
its ends to the respective glasses or their frames. This spring, instead of being
continuous as usual, is divided transversely at the middle and the adjacent ends united
by a hinge or joint C, the top of which lies in a horizontal position, that is to say, in
a line parallel with the focal axis of the glasses. The hinge is of the familiar knuckle

page_text: type, that is, provided with shoulders a, by which its opening movement is limited.
This joint permits the glasses to be folded together or overlapped by moving them in
planes parallel with their own surfaces. As the glasses are moved apart to a proper
position for use, the shoulders of the hinge are brought into action, and the two ends
of the spring maintained in such relation that they will he properly strained in the
act of applying the glasses to the nose as usual. It is to be observed that under
this construction the spring is entirely relieved from strain when the glasses are not
in use.
It is to be noted also that the arrangement of the hinge-pin or pivot in a
horizontal position ensures the perfect rigidity of the joint when the glasses are
opened so that they cannot fold or bend out of position as would be the case were the
pivot arranged vertically.
As shown in the drawings the hinge-joint is formed by properly bending and cutting
the ends of the spring sections that they may be fitted together after the manner of
an ordinary hinge. The stops or shoulders a, are formed of separate plates applied
to the outer surfaces of the springs and riveted thereto. It is to be distinctly
understood, however, that any equivalent form or joint may be substituted therefor.
My correspondent is aware that it is old to construct an eye-glass with a divided
spring, having its two parts united by a vertical pivot so that the two lenses could be
folded together like the leaves of a book, and to this construction he lays no claim.
Having now particularly described and ascertained the nature of the said invention,
and in what manner the same is to be performed, as communicated to ine by my
foreign correspondent, I declare that what I claim is :-
1. In an eye-glass having its two lenses connected by a spring, a divided spring
having its two parts united by a hinge or joint, the axis of which is parallel with the
focal axis of the glasses.
2. The combination of the lenses A A, the divided spring B, and knuckle-joint C,
having a horizontal axis, substantially as described.
3. The lenses A, the divided spring B, having its adjacent ends formed and united
by a horizontal pivot in combination with shoulders or stops a.
Dated this 27th day of June 1887.
3
WM. P. THOMPSON & Co.,
Agents for the Applicant.