Year: 1887

page_text: 1, GEORGE WILLIAM ELLIOTT of No. 12 Clarkehouse Road, Sheffield in the County
of Yorkshire, Mining and Mechanical Engineer do hereby declare the nature of this
invention to be as follows:-
This Invention has for its object the construction of dark slides for cameras for
photographic purposes, so as greatly to reduce the cost of production, and also make
them less bulky and more portable.
Dark slides for cameras have hitherto been made of wood or cardboard. Those
made of cardboard being practically useless, and the use of wood rendering the
others very costly, on account of the labour necessary for their construction, and
bulky, on account of the thickness required to give the necessary strength for
working.
These defects are obviated by this invention which consists of constructing them of
metallic sheets, or sheets of vulcanised fibre, vulcanite, or other suitable material
capable of being folded, creased, stamped, or pressed into the required shape.
A piece of sheet tin or other suitable material of the required size is so stamped
or pressed or folded on its edge as to form a groove for the sliding door or shutter
and at the same time be perfectly light tight, and of sufficient depth to allow of the
sensitive plate being placed between the back of the slide and the sliding door.
Two of these pieces are placed at the required distance apart, according to the size
of the slide or plate to be used, and are joined together by the piece forming the back
of the slide.
The ends are made light tight by the insertion of suitable material such as cloth,
bearing against the inside of the sliding door or shutter, or by being folded over in a
similar manner to the sides. The whole slide, excepting the sliding door or shutter
may be made of one piece stamped or pressed into shape, or may be any com-
bination of pieces to suit the convenience of manufacture.

page_text: The sliding door or shutter has its two outside edges folded so as to work in the
folds formed in the body part, the whole forming a level or flush surface and a
perfectly light tight joint.
A portion of the back is indented so as to bear against the sensitive plate and by
means of the spring of the back plate, hold the sensitive plate in its position.
The folds forming the guides for the sliding door or shutter may be such that the
slide may not require folding on its edges which work in these guides, but be kept
plain.

page_text: COMPLETE SPECIFICATION.
Improvements in Dark Slides for Cameras for Photographic
Purposes.
I, GEORGE WILLIAM ELLIOTT, of No. 12 Clarkehouse Road, Sheffield, Yorkshire,
Mining and Mechanical 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 :-
A piece of tin or other suitable material of the requisite size, is so stamped or folded
on its edge as to form a groove for the sliding door or shutter, and at the same time
be perfectly light tight, and of sufficient depth to allow of the sensitive plate being
placed between the back of the slide and the sliding door.
Two of these are placed at a requisite distance apart, according to the size of slide,
or plate to be used, and are joined together by the piece forming the back of the slide.
The ends are made light tight by the insertion of suitable material bearing against
the inside of the sliding door or shutter, or by being folded over in a similar manner
to the sides.
The whole slide, excepting the sliding door or shutter, may be made of one piece,
stamped or pressed into shape, or of any combination of pieces, to suit the convenience
of manufacture.
The sliding door or shutter has its two outside edges folded so as to work in the
folds formed in the body part, the whole forming a level, or flush surface, and a
perfectly light tight sliding joint.
The folds forming the guides for the sliding door may be such that the slide may
not require folding on its outside edges, which work in these guides, but be kept
plain, or slightly dished for strength.
A portion of the back is indented so as to bear against the sensitive plate, and by
means of the spring of the back plate of the dark slide, hold the sensitive plate in its
proper position.
To render the manner of carrying out this invention clearly understood, a sheet of
drawings is annexed, in which like letters refer to like parts in each figure.
Fig. 1. is a plan of a dark slide complete, constructed according to one modification
of this invention.
Fig. 2. is a sectional side view of Fig. 1.
Fig. 3 is a sectional end view of Fig. 1.
Fig. 4. is a sectional end view of the back part of the dark slide.
Figs. 5, 6, are sectional end views of the two side pieces which form the grooves or
slides for the sliding shutter.
the
Fig. 7. is a sectional end view of the sliding shutter with its sides folded to slide in
grooves formed by the two side pieces shown in Figs. 5. 6.
Figs. 8. 9. are sectional end views of the two side pieces which form the grooves or
slides for the sliding shutter when it is not folded to fit the grooves.

page_text: Fig. 10 is a sectional end view of the shutter made to fit the grooves formed by
Figs. 8. 9 and with the edges not folded, but made by preference dished at the edges
to stiffen the shutter instead of being straight.
In these figures a. is the back part of the dark slide, having its edges b. turned up
to form a dish.
The two side pieces c. shown in Figs. 5. 6. or 8. 9. are secured at each side of the
back piece, as at c. in Figs. 1. 2. 3. and form the grooves g. g for the sliding shutter /.
forming therewith a perfectly light tight sliding joint.
The sensitive plate 4. is kept in position at the sides by the sides of the grooves g. I.
and at the ends, by pieces of wood i. or other suitable material which have on their
upper surfaces a piece of cloth j. or similar substance to form a light tight packing
against the sliding shutter f
The back part of the dark slide a. is indented at c. so as to press against the
sensitive plate and hold it up to the moveable stops k.
In order to prevent the sliding shutter f. from being drawn out too far, two
strips m. on the shutter f. are severed from it excepting at one end nearest the end of
the shutter and then bent down as shown at m. in fig. 2. so that when the shutter is
drawn out the proper distance, the pieces m. come in contact with the edge of the back
part of the dark slide at n. n. and prevent the shutter. being drawn out too far.
I would have it understood that I do not confine myself to the precise modes of
carrying out this invention as herein illustrated, as these methods may be modified in
numerous ways in detail without departing from the principle of construction set
forth.
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-
Making dark slides for Cameras for Photographic Purposes of metallic sheets or
other suitable material capable of being folded, creased, stamped or pressed, and so
folded, creased, stamped or pressed into the required form to render a light tight
sliding joint, with the sliding shutter and its slides, substantially as described and
illustrated herein.