Improvements in Photographic Cameras.
Year: 1889

page_text: Date of Application, 6th Nov., 1889-Accepted, 21st Dec., 1889
COMPLETE SPECIFICATION.
Improvements in Photographic Cameras.
We, THOMAS RUDOLPH DALLMEYER, of 25, Newman Street, Oxford Street, in the
County of London, Optician, and FRANCIS BEAUCHAMP, of Hope Cottage, Whale-
bone Lane, Chadwell, Romford, in the County of Essex, 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 :-
Our invention relates to photographic cameras and has for its object to prevent the
expansible portion of a camera from sagging or bending, owing to its weight, when
in its extended or partly extended position, and so cutting off some of the rays of
light from the plate as has been the case with extensible cameras as heretofore
constructed.
According to our invention, the extensible portion of a camera is built up upon
a spring the shape of which corresponds to the shape of the said extensible portion in
transverse section, the convolutions of the said spring preferably gradually decreasing
in diameter so that one convolution will lie within the other and so that when the
camera is extended the extensible portion will have a tapering shape.
To enable our invention to be fully understood we will describe the same with
reference to the accompanying drawings, in which,
Figure 1 is a side elevation of a camera having the extensible portion constructed
according to our invention.
Figure 2 is a longitudinal section through a part of the said extensible portion.
Figure 3 is an end view of the spring or support upon which the extensible portion
is built up; and
Figure 4 is a side elevation of the same.
Figures 5 and 6 are views illustrating a modified form of support, and,
Figures 7 and 8 are views illustrating another modification.
a indicates the base of the camera, 6 the fixed front portion, c the movable portion
and d the extensible portion which is at its ends secured to the portions 6 and c.
e is the support upon which the said extensible portion is built, the said support
occupying the position shewn in Figure 2 at the extremities of the outer angles of
the folds of the leather or other covering. As herein before stated the said support is
advantageously so formed that the convolutions thereof will fit one within the other
as shown in Figure 3 so that when the support is extended it will have a tapering
shape as shown in Figure 4.
It will be obvious that the extensible portion of a camera constructed as herein-
before described has a continuous groove f formed by the folds around it, instead of
the folds being in a series of parallel planes as heretofore.
In the modification of our invention shewn in Figures 5 and 6 the support instead
of being formed of a continuous wire as hereinbefore described is constructed with a
series of sections g. These sections as shewn are formed of tubular material, the
connection of the sections being effected by means of pins h, h secured at one end
in the sections and adapted to enter the ends of the adjacent sections. Any other
means, however, may be employed for effecting the connection.
In the modification illustrated in side elevation in Figure 7 and in front elevation
in Figure 8 a number of frames i, i are joined together at j, j.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
(1.) A photographic camera the extensible portion of which is built up upon a
denbatantially of described

page_text: (2.) The extensible portion of a camera built up upon a continuous wire support,
substantially as described.
(3.) The support formed of a series of sections or frames substantially as described.
(4.) The improvements relating to the manufacture' of 'the extensible portions of
cameras hereinbefore described and illustrated in the accompanying drawings.
Dated the 6th day of November 1889
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.