Improvements in or relating to the Construction of Prismatic Binoculars and other Prismatic Optical Instruments.
Year: 1899

page_text: Date of Application, 27th Oct., 1899
Complete Specification Left, 19th July, 1900-Accepted, 25th Aug., 1900
Improvements in or relating to the Construction of Prismatic
Binoculars and other Prismatic Optical Instruments.
I, JAMES AITCHISON, of 47, Fleet Street, in the City of London, Optician, do
hereby declare the nature of my said invention to be as follows:-
My invention relates to an improved method of mounting the prisms and
lenses of prismatic glasses and the like, and consists in providing means whereby
the assembling or fitting-together of the parts of glasses of this type is greatly
facilitated and whereby the prisms may be readily removed for cleansing purposes
and refitted without in any way affecting the optical accuracy of the various
prisms and lenses.
I construct a rigid frame or support the exterior shape of which is fashioned
according to the shape of the case or barrel in which it is to be fitted, and provide
the same with fixed tubes and holes in such a manner that the positions of the
prisms are definitely fixed relatively to each other; the eye pieces are independent
of this frame or support, but are each arranged to telescope with a corresponding
tube fixed in the frame.
The frame is formed with discs, planes, or tables which are perforated corre-
sponding to the tubes, over which holes the prisms are easily fitted in position
by any suitable clamping device; the parallelism and optical accuracy of the
planes of the prisms is thus ensured without further adjustment.
1 3711
1000
JAMES
AITCHISON.
By George Downing & Sons,
Chartered Patent Agents,
8, Quality Court, London, W.C.
Improvements in or relating to the Construction of Prismatic
Binoculars and other Prismatic Optical Instruments.
I, JAMES AITCHISON, of 47, Fleet Street, in the City of London, Optician, do
hereby declare the nature of my said invention and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement:---
My invention relates to an improved method of mounting the prisms and
lenses of prismatic glasses and the like, and consists in providing means whereby
the assembling or fitting-together of the parts of glasses of this type is greatly
facilitated, and whereby the prisms may be readily removed for cleaning purposes

page_text: and refitted without in any way affecting the optical accuracy of the various
prisms and lenses.
And in order that my said invention may be particularly described and
ascertained, reference is hereby made to the accompanying drawings in which
similar letters of reference indicate corresponding parts.
Fig. 1 is an elevation and Fig. 2 a plan of a frame constructed according to
my invention as applied to prismatic binoculars.
Fig. 3 is a section on the line of Fig. 2 and Fig. 4 is a section on the
line yy of Fig. 1.
I construct a rigid frame or support the exterior shape of which is fashioned
according to the shape of the case or barrel in which it is to be fitted; the frame
shown in the drawing and hereinafter described is designed for binoculars
constructed under my former Patent No. 26354 of 1898 a pair being used.
The frame is formed with discs, planes or tables a, a', a², connected together
and supported by tubular pillars 6 6 the top plane a is formed with two holes c, c¹
and is fitted with a tube in which the eye lens tube telescopes, the two tubular
pillars b, being preferably connected by a web e and connecting the top plane
with the middle plane a¹. This plane a¹ is also perforated at coinciding with
the hole c¹ of the plane a. The bottom plane a² is of somewhat larger diameter
than the others so as to form a flange to govern its position in the case or barrel;
the lower end of the tubular pillar is internally screw-threaded to receive the
objective.
The planes are formed perfectly parallel to one another so as to support the
prisms as indicated by the dotted lines in Fig. 1: their correct position may
be further ensured by dishing the planes as indicated by the dotted lines in
Figs. 2 and 4, whereby the prisms are sunk slightly below the surface of the
planes a suitable rib or projections or a raised plane may be substituted for
the countersunk design so as to locate the correct positions of the prisms. The
latter may be secured in position by band clamps or by any other suitable means.
The positions of the prisms being thus definitely fixed relatively to each
other and to the lenses (whereby the parallelism and optical accuracy of the
planes of the prisms is ensured without further adjustment) the removal and
refitting of the prisms and lenses is greatly facilitated and cleaning or repairing
may thus be effected without in any way affecting the optical accuracy of the
various prisms and lenses.
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:
In prismatic binoculars and other prismatic optical instruments, the means
described for supporting or mounting the prisms and lenses, consisting of a
rigid frame or support adapted to be fitted in the case or barrel, formed with
planes or tables parallely arranged and supported at a suitable distance apart by
tubular pillars, constructed with the openings and with (or without) the means
set forth for further locating the correct position of the prisms, substantially as
and for the purposes described.
JAMES
AITCHISON.
By George Downing & Sons,
Chartered Patent Agents.
8, Quality Court, London, W.C.