An Improved Photographic Dark Slide Recorder.
Year: 1892

page_text: Date of Application, 10th Nov., 1892
Complete Specification Left, 3rd Aug., 1893-Accepted, 23rd Sept., 1893
PROVISIONAL SPECIFICATION.
An Improved Photographic Dark Slide Recorder.
We, JOHN EDWARD THORNTON, and EDGAR PICKARD of Altrincham, near
Manchester, Manufacturers, do hereby declare the nature of this invention to be
as follows:-
The object of this invention is to provide a simple device for attachment to a
photographic dark slide for the purpose of showing whether the sensitive plate or
plates in the slide have been exposed or not.
It is constructed of two thin plates of metal or other suitable material about
"x"hinged together at one side. The ends of the plates may be slightly
turned up so as to form bearings for the hinge. A spring is so placed at the hinged
side that it will cause the top plate or lid to stand open, or at right angles to
the bottom plate. Any suitable form of spring may be used, but we prefer a
straight piece of steel wire held at one end by the lid, and the other end by the
bottom plate The word " exposed" may be printed on the inner side of the lid,
so that it is visible only when the lid is open.
The bottom plate is attached to the end of the dark slide in such a position
that the projecting part or top of the shutter of the slide, (or a projection attached
to the shutter) will fit over the lid and keep it closed when the shutter is pushed
right in.
When the shutter is withdrawn to expose the plate the lid flies open disclosing
the word "exposed," and it remains in this position when the shutter is pushed
home again.
The lid may be closed by the finger to "set" it, at the same time that the slide
is charged with fresh plates.
T
1000
J. E. THORNTON.
EDGAR PICKARD.
COMPLETE SPECIFICATION.
An Improved Photographic Dark Slide Recorder.
We, JOHN EDWARD THORNTON, and EDGAR PICKARD, of Altrincham, near
Manchester, in the County of Chester, Manufacturers, 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:-
The object of this invention is to provide a simple device for attachment to a
photographic dark slide for the purpose of showing whether the sensitive plate
or plates in the slide have been exposed or not.
It consists essentially in the combination with the dark slide of a recorder con-
structed with two plates or their equivalent hinged together on a spring by which
they are forced apart or caused to open or stand at right angles to one another
when not held down by the shutter of the slide.
It will be fully described with reference to the accompanying drawings.
Fig. 1. Perspective view of the upper part of the dark slide with the invention
applied thereto.
Fig. 2. Front elevation of same.
Fig. 3. End elevation.

page_text: Fig. 5. Front elevation of the appliance open and removed from the dark slide.
Fig. 6. Plan of Fig. 5.
The dark slide A. and the shutter B are constructed in any usual or ordinary way
and to the top edge is applied our improved recorder or appliance C which when
the plate is placed in the shutter is held close by a projecting edge or catch bon
the shutter and opens by means of a spring when the shutter is drawn out showing
on the face the word "exposed" or other word or mark to indicate that the shutter
has been drawn cut.
The recorder C is constructed of two thin plates c of metal or other suitable
material of about by or other suitable dimensions hinged together at one
side. The plate c may be slightly turned up at the edges to form bearings for the
hinge. The hinge is formed of a piece of spring wire passed through the turned up
edges or lugs e¹ one end being held by the top plate or lid and the other by the
bottom plate. It is evident that the two plates may be pivoted together on an
ordinary pivot and any suitable spring employed to force or hold them asunder or
open that is with the top plate at right angles to the bottom one.
The word "exposed or other word or mark may be printed on the inner side of
the lid or top plate so that it is visible only when the lid is open.
The recorder is attached-preferably by screws passing through the bottom
plate to the upper edge of the dark slide in such a position that the projecting
part or top of the slutter B of the slide will fit over the lid and keep it closed
when the shutter is pushed right in. Or another projection or catch-such as b¹
Fig. 4-may be attached to the shutter for the same purpose.
When the shutter is withdrawn to expose the plate the lid. flies open disclosing
the word "exposed" and it remains in this position when the shutter is pushed
home again.
The lid may be closed by the finger to "set it at the same time that the slide is
charged with fresh plates.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The combination with the dark slide of a recorder or appliance for indicating
when the shutter has been raised and the plate exposed consisting of a hinged
plate which is opened by a spring and held closed by the top of the slide or a
projection or catch thereon substantially as described.
2. A recorder for the dark slides of photographic cameras constructed of two
plates hinged together on a spring wire or hinge, one to be attached to the top of
the slide and the other with the word "exposed" inscribed thereon to be held
closed by the top of the shutter or by a projection or catch thereon substantially
as described and shown.
Dated this 2nd day of August 1893
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent Agents.