Improvements in Plate Changing Devices for Photographic Apparatus.
Year: 1892

page_text: Date of Application, 14th June, 1892
Complete Specification Left. 14th Mar., 1893-Accepted, 22nd Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in Plate Changing Devices for Photographic
Apparatus.
A communication by DRESSLER & HEINEMANN, of 45, Theatinerstrasse, Munich,
in the Empire of Germany, Dealers in Photographic Apparatus.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for
Foreign Patent 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 to be as follows:-
In this new plate-changing device, the photographic plates intended for exposure
are inserted backwardly in the camera and are maintained against a case by means
of a spring attached to the removable back of the camera; this case may be
inserted in the camera from above, from below or from the sides. This case has, at
its lower hinder edge, a slot of such a size that a plate or a frame containing the
same may be easily inserted in the case. Clamp springs, acting against one another,
are arranged in this case. The case, when inserted, presses down a sheet spring
attached to the bottom of the camera and bent upwards at right angles, which
spring, being released when the case is drawn out, springs up, and thus, as will be
hereinafter described, forms a rest for the plates or frames pressed up against it;
the usual opening of the objective is provided, on which a suitable closing device
may be arranged.
The mode of working of the improved plate-changing device is as follows:-
The plates already exposed are contained in the aforementioned case, those to be
exposed in the space behind the same. If the front one of the unexposed plates is
to be exposed, the case is simply raised up. A projecting part of the case, or other
suitable device, prevents the case being entirely drawn out.
The following takes place when the case is drawn up :-
Firstly, the spring attached to the bottom of the camera springs up, which was
hitherto held down by the case; then the plates in the chamber are pressed
forward by means of the spring, so that the front one, which previously rested
against the hinder wall of the case, now stands with its lower part against the
curved up part of the spring, whilst, at the top, it rests against a projection formed
by the bottom of the case. Thereupon, if the objective shutter be removed, timed
or instantaneous exposures may take place, and then the case is pushed back again
into the camera. The foremost plate, which has just been exposed, thereupon
passes into the case through the slot in the same, where it is held by the two
springs, and places itself at the back of the plates already contained in the case.
The
The two springs, or their points of contact, press against one another in such a
way that the plates entering the case are pushed slantwise with their lower ends
projecting forward, in order to keep the slot free for another plate to enter.
unexposed plates are pushed slightly backwards by means of the tapered surface of
the back wall of the case, when the latter is inserted, and the plates again rest
against the back wall of the case.
If a fresh plate is to be exposed, the above described process is repeated.
Dated this 13th dor of June 1809

page_text: i
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COMPLETE SPECIFICATION.
Improvements in Plate Changing Devices for Photographic
Apparatus.
A communication by DRESSLER & HEINEMANN, of 45, Theatinerstrasse, Munich,
in the Empire of Germany, Dealers in Photographic Apparatus.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent 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 has for its object improvements in plate changing devices in
photographic apparatus.
On the accompanying drawing :-
Figures 1 and 2 show the longitudinal sections of a hand camera with this new
plate changing device applied to it.
The photographic plates intended for exposure are inserted backwardly in the
camera and are maintained against a case 6 by means of a spring a attached to
the removable back of the camera; this case may be inserted in the camera from
above, from below or from the sides. On the drawing, it is shown as inserted
from above.
Figure 1 shows the case drawn out; and
Figure 2, when it is inserted in the camera.
This case has, at its lower hinder edge, a slot e of such a size that a plate, or
à frame containing the same, may be easily inserted in the case. Clamp springs d,
acting against one another, are arranged in this case b. The case, when inserted,
presses down a sheet spring e, attached to the bottom of the camera and bent
upwards at right angles, which spring, being released when the case is drawn out,
springs up, Figure 1, and thus, as will be hereinafter described, forms a rest for
the plates or frames, pressed up against it; the usual opening of the objective is
provided, on which a suitable closing device may be arranged.
The mode of working of the improved plate changing device is as follows
The apparatus, when at rest, assumes the position shown in Figure 2. The
plates already exposed are contained in the aforementioned case b, those to be
exposed in the space g behind the same. If the front one of the unexposed plates
is to be exposed, the case is simply raised up into the position shown in Figure 1.
A projecting part h of the case, or other suitable device, prevents the case being
entirely drawn out.
The following takes place when the case bis drawn up :-.
Firstly, the spring e, attached to the bottom of the camera, springs up, which
was hitherto held down by the case; then the plates in the chamber g are pressed
forward by means of the spring a, so that the front one, which previously rested
against the hinder wall of the case b, now stands with its lower part against the
curved up part of the spring e, whilst, at the top, it rest against a projection i
formed by the bottom of the case. Thereupon, if the objective shutter be
removed, timed or instantaneous exposures may take place, and then the case b is
pushed back again into the camera. The foremost plate, which has just been
exposed, thereupon passes into the case through the slot c in the same, where it is
held by the two springs d, and places itself at the back of the plates already
contained in the case..
The two springs d, or their points of contact, press against one another in such
a way that the plates entering the case bare pushed slantwise with their lower
ends projecting forward, as shown on the drawing, in order to keep the slot e free
for another plate to enter. The unexposed plates are pushed lightly backwards by

page_text: means of the tapered surface of the back wall of the case b, when the latter is
inserted, and the plates again rest against the back wall of the case and the spring e
is again pressed down, see Figure 2.
If a fresh plate is to be exposed, the above described process is repeated.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondents, I declare that what I claim is :-
1. A plate changing device for photographic apparatus, in which the plates,
which are to be changed and which are pushed forward by means of a spring a into
the plane for the picture, can enter into a case 6 (arranged in an opening in the
side wall of the camera) on the insertion of the case into the camera, through a
slot c in the case, and be removed from the slot by means of springs d d after the
lower rest e, which is held down by the case, has released the plates, all substan-
tially as herein before described.
с
Dated this 13th dor of March 1893
WM. P. THOMPSON & Co.,
Agents for the Applicant.