Improvements in and connected with Dark Slides for Photographic. Cameras.
Year: 1894

page_text: Date of Application, 11th Dec., 1894
Complete Specification Left, 10th Oct., 1895-Accepted, 23rd Nov., 1895
IROVIDIUNAL DICITIATION.
Improvements in and connected with Dark Slides for Photographic.
Cameras.
I, MORITZ ALPHONS 'STÜBEL, of 10, Feldgasse, Dresden, in' the Empire of
Germany, Doctor of Philosophy, do hereby declare the nature of this invention to
be as follows:
This invention has reference to an improved construction of a dark-slide which
is also suitable for transporting the sensitive plate or film prior to and after
exposure; to a frame or holder which is adapted to be inserted in the camera and
is arranged to receive the dark-slide and also to support the ground glass focussing-
screen; and to means for opening and closing the dark-slide within the said frame
from outside the camera.
A dark-slide according to my invention, besides perfectly excluding the light
when closed and being adapted to be opened and closed within its frame in the
camera, possesses the advantages of being very light and requiring very little
space, its dimensions not exceeding those of a letter of moderate size. The dark-
slide is therefore particularly adapted for photographing away from the studio and
for the use of tourists..
The dark-slide consists of a frame or casing hereinafter referred to as the inner
casing for the insertion of the sensitive plate or film, of a pocket for enclosing the
said casing so as to protect it from the action of light, and of a frame or casing
hereinafter referred to as the outer casing for receiving the pocket.
The inner casing comprises two rectangular flat pieces of cardboard or other
suitable material, which are connected at one end by means of a clamp made of
sheet metal or other suitable material and provided with holes for the purpose
hereinafter described. One of these pieces is full; but the other has an opening
cut in it corresponding approximately in shape to, but somewhat smaller than the
sensitive plate or film to be carried, and a third piece of cardboard of frame-like
shape is secured to the inner side of this piece in order to form a recess adapted to
receive the sensitive plate or film.
The pocket is open at one of its ends and forms a sheath, into which the inner
casing is arranged to fit tightly. It is provided at its closed end with holes and
is suitably recessed at its other end to receive the clamp aforesaid.
The outer casing is also in the form of a pocket with both sides cut out to about
the size of the sensitive plate or filin. It is provided with holes at its closed end
corresponding to the holes in the aforesaid clamp, and also with slots at its open
end, which correspond to the holes of the pocket and are open to the edge of
the casing. The dark-slide may advantageously be made of black paper or
cardboard.
A sensitive plate or film enclosed in a dark-slide of the kind just described is
completely protected against light; such dark-slide is very suitable for transport,
being of very little weight and of only about one fourth of the thickness of the
usual wooden dark slides.
For inserting this dark slide with the enclosed sensitive plate or film, into a
camera I employ a frame which consists of three parts. One of these parts is cut
out to about the size of the plate or film. The middle part, to which the other
two parts are hinged, is recessed to be adapted to receive the ground glass

page_text: focussing-screen. After a focussing operation has been performed, the frame is
removed from the camera, the focussing-screen taken out and the dark slide herein-
before described put into exactly the same place. The third part of the frame,
which is full, is now turned over the dark slide.
The said full part or cover carries a slide' provided with a rack, into which
gears a pinion adapted to be rotated from outside of the camera by suitable means
such as a crank. At one end of the slide there are provided pins which are
adapted to pass through the aforesaid slots in the outer casing and to engage in
the aforesaid holes in the pocket; and the middle part of the frame is provided
with pins adapted to engage in the aforesaid holes in the outer casing and in-the
holes of the inner casing and thus to keep the entire dark slide in the frame. The
position of the dark slide in the frame is furthermore secured by spring buttons
provided in the cover and so arranged as to press slightly upon the outer casing
when the cover is folded over it.
When the frame with the dark-slide in it, has been inserted into the camera,
the crank is turned so as to move the slide outwards, thus causing it to withdraw
the pocket from the outer casing by means of its pins. By so withdrawing the
pocket, the sensitive plate or film in the inner casing is exposed within the camera.
When it is desired to close the dark-slide, the crank is turned the reverse way,
thus inserting the pocket into the outer casing and passing it over the inner casing,
thereby covering the sensitive plate or film, which is now completely protected
from the action of light. The frame may now be removed from the camera and
opened in order that the dark-slide may be removed and a fresh one substituted.
The dark-slide may now be simply put into a paper envelope, on which any
necessary remarks or notes may be made, and the slide kept until it is convenient
to develop the plate or film in the dark-chamber.
Any other suitable mechanical device for operating the pocket within the
camera may be substituted for the crank, rack, and pinion hereinbefore described;
or the pocket may, if preferred, be operated by hand.
The lightness and the compactness of the dark-slide herein before described
will allow the landscape photographer or the tourist to carry as many slides, each
provided with a sensitive plate or film, as he intends to take photographic pictures,
the inconveniences hitherto attendant on the transport of plates or films and the
exchange of the same in the camera being entirely avoided.
Dated this 11th day of December 1894.
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
Improvements in and connected with Dark Slides for Photographic
Cameras.
1, MORITZ ALPHONS STÜBEL, of 10, Feldgasse, Dresden, in the Empire of
Germany, Doctor of Philosophy, 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 reference to an improved construction of dark-slide which is
also suitable for transporting the sensitive plate or film prior to and after exposure;
to a frame or holder which is adapted to be inserted in the camera and is arranged
to receive the dark-slide; and to means for opening and. closing the dark-slide
within the said frame from outside the camera.
A dark-slide according to my invention, besides preferably excluding the light
when closed and being adapted to be opened and closed within its frame in the
camera, possesses the advantages of being very light and requiring very little

page_text: IT IS
space, its dimensions not exceeding those of a letter of moderate size.
therefore particularly adapted for photographing away from the studio and for the
use of tourists.
: "
The dark-slide consists of a frame or casing (hereinafter referred to as the inner
casing) for the insertion of the sensitive plate or film; a pocket for enclosing the
said casing so as to protect it from the action of light; and of a frame or casing
(hereinafter referred to as the outer casing) for receiving the pocket.
Figs. 1 to 6 of the accompanying drawings represent such a dark-slide, Figs. 1
and 4 being an elevation and a longitudinal section respectively of the inner
casing, and
Figs. 2 and 5 and Figs. 3 and 6 similar views of the pocket (the inner casing
being partly inserted therein) and the outer casing respectively.
The inner casing. a (Figs. 1 and 4) comprises two rectangular flat pieces of
cardboard or other suitable material, which are connected at one end by means of
a clamp a made of. sheet metal or other suitable material and provided with
holes and for the purpose hereinafter described. One of these pieces is full;
but the other has an opening cut in it corresponding approximately in shape to, but
somewhat smaller than, the sensitive plate or film to be carried; and a third piece
of cardboard of frame-like shape is secured to the inner side of one of these pieces
in order to form a recess adapted to receive the sensitive plate or film. The
pocket 6 (Figs. 2 and 5) is open at one of its ends and forms a sheath, into which
the inner casing a is arranged to fit tightly. It is provided at its closed end with
The outer
holes and is suitably recessed at its other end to receive the clamp a¹.
casing c is also in the form of a pocket but has both sides cut out to about the size
of the sensitive plate or film. It is provided with holes at its closed end
corresponding to the holes in the clamp a', and also with slots at its open end
which correspond to the holes of the pocket b and are open to the corresponding
edge of the casing. The dark-slide thus constructed may advantageously be made
of black paper or cardboard.
A sensitive plate or film enclosed in a dark-slide of the kind just described,
is completely protected against light; such a dark-slide is very suitable for
transport, being of very little weight and of only about one fourth of the thickness
of the usual wooden dark-slides.
For inserting this dark-slide with the enclosed sensitive plate or film, into
a camera I employ a frame, which is shown folded up and containing the dark slide
in longitudinal section in Fig. 7 and open in Fig. 8 of the accompanying
drawings.
One of the parts R¹ of this frame is cut out to about the size of the plate or film
and is recessed to adapt it to receive the dark-slide.
The full part or cover R of the frame carries a slide Z provided with a rack c¹
into which gears a pinion adapted to be rotated from outside the camera by
suitable means, such as a crank k. At one end of the slide Z there are provided
pins s s¹ which are adapted to pass through the slots in the outer casing c and to
engage in the holes in the pocket b; and the part R' of the frame is provided
with pins adapted to engage in the holes 12 in the outer casing c and in the
holes, of the inner casing a and thus to keep the entire dark-slide in the
1rame R R. The position of the dark-slide in the frame is furthermore secured
by spring buttons a, ẞ, y and provided in the cover R and so arranged as
to press slightly upon the outer casing c when the said cover is folded over it.
When the frame with the dark-slide in it, has been inserted into the camera, the
crank k is turned so as to move the slide Z outwards thus causing the slide Z to
withdraw the pocket from the outer casing c, by means of its pins s, s' into the
position indicated by dotted lines in Fig. 7. By so withdrawing the pocket b, the
sensitive plate or film in the inner casing a is exposed within the camera.
When it is desired to close the dark-slide, the crank k is turned the reverse way,
thus inserting the pocket b into the outer casing and passing it over the inner
casing a, thereby covering the sensitive plate or film, which is now completely

page_text: protected from the action of light. The frame R R may now be removed from
the camera and opened in order that the dark-slide may be removed and a fresh one
substituted. The dark-slide may now be simply put into a paper envelope on
which any necessary remarks or notes may be made, and the slide kept until it is
convenient to develop the plate or film in a dark-chamber.
Any other suitable mechanical device for operating the pocket 6 within the
camera may be substituted for the crank, rack, and pinion bereinbefore described;
or the pocket may, if preferred,, be operated by hand.
The lightness and the compactness of the dark-slide hereinbefore described will
allow the landscape photographer or the tourist to carry as many slides, each
provided with a sensitive plate or film, as he intends to take photographic pictures,
the inconveniences hitherto attendant on the transport of plates or films, and the
exchange of the same in the camera, being entirely avoided.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
.claim is :-
1. A. dark-slide suitable for exposing and transporting sensitive plates or films
for photographic purposes, comprising an inner frame or casing a for receiving a
sensitive plate or film; a pocket 6 for enclosing the said casing, and an outer frame
or casing c'for receiving the pocket b, the arrangement being such that the sensitive
plate or film can, whilst within a camera, be exposed by the complete or partial
withdrawal of the pocket b and be again protected from the action of light by the
ready restoration thereof, substantially as described.
2. In combination with a dark-slide of the kind specified in the preceding claim,
a frame substantially as herein before described, into which the dark-slide can be
inserted for the purpose of exposing a sensitive plate or film in a camera and which
is adapted to facilitate the withdrawal and the restoration of the pocket 6 within
the camera by hand or by mechanical means and to keep the frames or casings a
and c of the dark-slide stationary during these operations as set forth.
3. My improved dark-slide constructed and arranged as hereinbefore described
with reference to and shown in Figs. 1 to 6 inclusive of the accompanying
drawings.
4. For containing a dark slide such as herein before described and for with-
drawing and removing the movable pocket 6 thereof, a frame constructed and
arranged as herein before described with reference to and shown in Figs. 7 and 8 of
the accompanying drawings.
Dated this 10th 1
11007
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.