An Improved Opera Glass.
Year: 1896

page_text: Date of Application, 27th May, 1896-Accepted, 4th July, 1896
COMPLETE SPECIFICATION.
An Improved Opera Glass.
I, EDMOND BLOCH, of No. 1 Avenue de la Republique, Paris, in the French
Republic, Manufacturer, 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 certain improvements in binoculars and opera glasses,
more especially those of the long-handled class, and has for object to provide
means for effecting the withdrawal of the object-glasses from the eye-glasses and
the focussing by the movement of the handle or holder.
I attain this object. by hinging the handle at one extremity to one of the eye-
pieces (preferably the right-eye-piece) and forming upon an extension of the
handle an eccentric guide or cam arranged to operate jointed cross-levers or a
lazy-tongs, in such a manner that the mere action of depressing the handle will
expand the cross-levers and thereby extend the object-glasses from the eye-glasses
for the purpose of adjusting the focus. An advantage obtained by this arrange-
ment is that the binocular when not actually in use occupies a very limited space-
about 15 millemetres in depth.
In order to more clearly explain my invention, reference is made to the
accompanying drawings upon which-
Figure 1 is an elevation of a binocular constructed according to my invention
shewn in the closed position, with the handle raised level with the eye-glasses,
the dotted lines indicating the position of the handle when the glasses are extended
to their extreme limit;
Figure 2 being a plan of the same shewn in the closed position;
Figure 3, a similar view shewing the glasses fully extended
Figure 4 is an elevation of a binocular provided with a modified arrangement
of the operating device and shewn in the closed position.
In carrying out my invention I construct the binocular or opera-glass of two
frames, one a carrying the eye-glasses c, and the other b, the object glasses d, as
represented on Figures 1, 2, and 3. The two pieces or frames a, b, are connected
together by means of two hinged cross-levers e, f, attached to each other by
pivots o, and forming together a lazy-tongs. The extremities of one cross-levere
are pivoted directly on the frames a and b respectively, while the other cross-
lever is hinged at its extremities to sliding-pieces g and h movably arranged
upon the frames b and a respectively. The sliding-piece h is provided on its inner
side or back with a small bent arm or projection i, carrying a pin or stud j for
the purpose of engaging an eccentric cam or guide 1, described below.
The handle & of the binocular is pivoted upon the frame a so as to be capable
of rotating to a limited extent around the right-eye-glass, and has a prolongation
beyond its centre of rotation constructed in the form of an eccentric cam or
guide 1, to engage the stud j, as already mentioned.
From the foregoing description it will be readily understood that the binocular
thus constructed is closed or extended, and the object glasses are adjusted with
reference to the eye-glasses, by moving the handle k to or from the position
indicated by the dotted lines in Figure 1, whereby the eccentric guide causes
the stud to move to or from its extreme limit . On the drawings only the
extreme positions are shewn, but any intermediate position and focus may be
obtained by adjusting the handle k nearer to, or further from a vertical position
relatively to its centre of rotation, as may be desired.

page_text: For the purpose of steadying the binocular during its adjustment, a suitable
finger-piece or ring m may be secured on the frame a at the side of the left-eye-
piece.
Or, in lieu of the above described arrangement of an eccentric cam for perating
the adjustment, I may adopt the modification shewn in Figure 4, of a toothed
segment n formed on the extremity of the handle k, and a horizontal toothed
rack p formed on the sliding-piece h by which the cross-levers or lazy-tongs e, f,
are operated. In this case in order to secure rigidity I connect the sliding-piece /
to a convenient point on the cross-lever f by means of another cross-lever f¹
having a vertical movement.
Or I may otherwise arrange the operating device in the form either of an
Archimedean screw, a double rack, or an eccentric.
The several parts of the binocular may be made either of aluminium or other
suitable metal as preferred.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. In opera-glasses or binoculars, the arrangement of hinged cross-levers e and f
forming a lazy-tongs connecting the eye-glass frame and object glass frame
together, and operated by the movement of an eccentric guide or cam l forming
part of a suitable handle k pivoted ou the eye-piece, for the purposes and as
described.
Dated this Twenty-seventh day of May 1896
GEDGE & FEENY,
60 Queen Victoria Street, London, E.C., Chartered Patent Agents.