Improvements in and relating to Carriers or Envelopes for, and to Means for, Exposing Photographic Dry Plates.
Year: 1893

page_text: Date of Application, 14th Nov., 1893
Complete Specification Left, 9th Aug., 1894-Accepted, 29th Sept., 1894
PROVISIONAL SPECIFICATION.
Improvements in and relating to Carriers or Envelopes for, and to
Means for, Exposing Photographic Dry Plates.
I, JAMES MCLACHLAN DOBSON, of Springpark, Springfield Avenue, Uddingston,
Lanarkshire, Sanitary Inspector, do hereby declare the nature of my invention to
be as follows:-
This invention has reference to and comprises improvements in envelopes or
carriers for photographic dry plates, and in appliances in connection with the
ordinary dark cell or slide used for exposing the plates in the camera, and its
object is to enable any number of dry plates, each enclosed in an envelope or
carrier, to be carried by the operator, and exposed singly, all in a more convenient
manner than by the methods heretofore in use.
According to one mode of carrying the improvements of this invention into
practice an envelope or carrier would be used of a form much the same as the
ordinary envelopes used for postal purposes, and preferably made of stout actinic
light proof orange or ruby coloured paper and of a size to hold the dry plate to be
used. This envelope would have the usual folding and closing gummed flap on its
back side and the inner surface of the plain front side would be lined with thin
cloth, preferably black, which is carried out through one of the ends for a short
distance, and this end is closed by securing by glue or equivalent material a small
folded over flap at the end of the back side of the envelope. The plates would be
inserted singly into envelopes, so prepared, within the dark room, with their
sensitive films next the cloth on the front side and the flaps being securely gummed
down, they could be freely handled under ordinary daylight without being injuriously
affected.
In order to expose in the camera dry plates enclosed in envelopes, as described a
dark cell or slide, preferably one formed for carrying a single plate, would be used
fitted with the improved appliances to be described. Upon the rear end and on
the outside of the sliding shutter which is drawn out to expose the dry plate, would
be mounted a transverse spindle or roller, carried in bearings secured at each side
to the shutter, and extended on one side to project beyond the bearing and over the
side bar of the frame of the slide, this projecting part being formed as a small
toothed pinion. A corresponding toothed rack would be secured on the same
side bar extending some distance from the front end towards the back and the
toothed pinion would take into and be revolved with the roller by this rack
when the shutter is drawn outwards. The roller may be smooth but would
preferably be roughened on its surface or be formed with teeth similar to the
pinion. To one end of this roller a small semi-circularly curved plate or cover
would be hinged or pivotted by a pin passing through the roller, so that the
plate can be folded down on the roller so as to grip the cloth of the envelope as
will be explained. When folded down this covering plate would be secured in
its closed position by a collar on the roller being slipped over its free end, said
collar being kept in position by a spring between it and the bearing at that
end of the roller. Other means of actuating the roller may be employed instead
of the rack and pinion arrangement.
To use these appliances the plate enclosed in its envelope would be placed within
the dark cell provided with the usual plate holder and sliding or hinged shutter
for the purpose, and the exposing shutter being drawn slightly open the projecting
cloth of the envelope would be passed out through the opening to the outside of

page_text: the cell and the shutter closed light tight on it. This projecting cloth would then
be turned over on to the roller and the covering plate of same shut down over it
and secured in position by the beforementioned collar, when all would be ready for
exposing the plate in the camera. On the exposing shutter being drawn out the
drag upon the cloth would tear away the whole front of the envelope and expose
the plate to the light and the roller being revolved by the rack and pinion would
roll the cloth and paper upon itself. After exposure the plate would be dropped
into a box suitably prepared and fitted to receive it from the dark cell without
exposing it to the influence of light.
Dated 13th November 1902
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.
COMPLETE SPECIFICATION.
Improvements in and relating to Carriers or Envelopes for, and to
Means for, Exposing Photographic Dry Plates.
I, JAMES MCLACHLAN DOBSON, of Springpark, Springfield Avenue, Uddingston,
Lanarkshire, Sanitary Inspector, do hereby declare the nature of my invention,
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following stateinent in writing, that is to say :-
This invention has reference to and comprises improvements in envelopes or
carriers for photographic dry plates, and in appliances in connection with the
ordinary dark cell or slide used for exposing the plates in the camera, and its
object is to enable any number of dry plates, cach enclosed in an envelope or
carrier, to be carried by the operator, and exposed singly all in a more convenient
manner than by the methods heretofore in use.
And in order that my said invention may be properly understood I have
hereunto appended an explanatory sheet of drawings, the same reference letters
being used to indicate the same or corresponding parts in all the figures where
shown.
According to one mode of carrying the improvements of this invention into
practice an envelope or carrier A, as shown in Figure 1 flat or unfolded is used, of
a form much the same as one description of the ordinary envelopes used for postal
purposes and preferably made of stout actinic light proof orange or ruby coloured
paper, or it might be black paper, and of a size to hold the dry plate used. This
envelope A has a folding and closing gummed flap A¹ on its back, when it is
folded up into shape and the inner surface of the plain front side is lined with thin
cloth A, preferably black a part A" of which is carried out through one of the
ends at the line a for a short distance, and this end is closed by securing by glue or
equivalent material the paper A' to the cloth A" along the line a and folding and
gumming same down. The photographic dry plates are inserted singly into
envelopes, so prepared within the dark room, with their sensitive films next the
cloth A, on the front side and the flaps a' a' a² and A' being securely gummed
down, they can be freely handled under ordinary daylight without being injuriously
affected.
In order to expose in the camera dry plates enclosed in envelopes as described a
dark cell or slide B, as shown in Figures 2, 3, 4, and 5 of the drawings, formed for
carrying a single plate is used, fitted with the improved appliances to be described.
Upon the rear end and on the outside of the sliding shutter B' which is drawn out
to expose the dry plate, is mounted a transverse spindle or roller b, shown detailed
in Figure 6, carried in bearings secured at each side to the shutter B', and
extended on one side, or on both sides as shown, to project beyond the bearings b¹
and over the side bars B2 of the frame of the slide B, this projecting part being
formed as a small toothed pinion 2. A corresponding toothed rack 6³ is secured on

page_text: the side bars B2 extending some distance from the front end towards the back and
the toothed pinion 6 takes into and is revolved with the roller 6 by this rack 63
when the shutter B' is drawn outwards. The roller may be smooth, as shown,.
but would preferably be roughened on its surface or be formed with teeth similar
to the pinion. To one end of this roller b a small semicircularly curved plate or
cover is hinged or pivotted by a pin passing through the roller b, so that the
plate can be folded down on the roller so as to grip the cloth A2 of the
envelope A as will be explained. When folded down this covering plate 6* is
secured in its closed position by a collar on the roller being slipped over its
free end, said collar being kept in position by a spring between it and the
bearing at that end of the roller b. Other means however of actuating the
roller may be employed instead of the rack and pinion arrangement such as cords.
and pulleys on the ends of the roller b.
To use these appliances the dry plate C, Figures 2 and 5 enclosed in its
envelope A is placed within the dark cell B which may be provided with the usual
plate holder 13 and sliding or hinged shutter for the purpose, and the exposing
shutter B being drawn slightly open the projecting cloth A" of the envelope A
would be passed out through the opening to the outside of the cell and the shutter
closed light tight on it.
However in the more complete arrangement as illustrated in the drawings, in
which the improvements of this invention are shown as in combination with a box
for receiving the exposed dry plates, the sliding or hinged shutter D¹ sometimes
employed for introducing the dry plates into the dark cell or slide B is dispensed
with and instead fitted to the receiving box D, shown in Figures 3, 4, 5 and 7 of
the drawings, and the plate C in its envelope A is placed within the dark slide B
by opening the exposing shutter B₁. The projecting cloth A" is then turned over
on to the roller b and the covering plate of same shut down over it and secured.
in position by the before mentioned collar 6, when all would be ready for exposing
the plate in the camera. On the exposing shutter B being drawn out the drag
upon the cloth A" would tear away the whole front of the envelope A, and expose
the plate C to the light and the roller being revolved by the rack and
pinion would roll the cloth and paper upon itself. The shutter B¹ being re-closed
after exposure the plate C would be dropped into a box D such as shown in the
drawings, suitably prepared and fitted to receive it from the dark cell without
exposing it to the influence of light. This box D with its closing shutter D¹ is
attached to the back of the exposing slide B in a light tight manner by rims d
sliding and entering into corresponding grooves formed in the frame of the dark
slide B. After each plate is exposed, the combined appliance is removed from the
camera and held with the receiving box D downwards so that when the shutter D'
is drawn open the plate with its envelope falls down into the box D the cloth
attached to the roller 6 being previously cut away. An ordinary plate box D' is
placed within the box D to receive the exposed plates and when filled, the box D
is removed from the slide B and the lid of the plate box D2 is placed with its
edges in the grooves d', shown in Figure 7 formed round the sides and one end of
the box D. The shutter is then drawn out until the edge of the end of the lid
falls into the groove d" formed across the shutter D'. When the lid of the plate
box is in this position the box D' containing the exposed plates is pushed upwards
within its deep lid by introducing the fingers through the openings D³ for the
purpose, in this way a box filled with exposed plates can be removed and the
operation of exposing plates continued until another box is filled, and so on.
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 :-
First. The construction and use of light proof carriers or envelopes for carrying
and exposing in the camera photographic dry plates, all substantially as herein
described and shown in the accompanying drawings.

page_text: Second. The construction of carriers or envelopes and exposing dark slides for
portably carrying and exposing in the camera photographic dry plates all
substantially as and for the purposes herein described and shown in the
accompanying drawings.
Third. The construction of dark slides for exposing in the camera photographic
dry plates having a roller fitted on the exposing sliding shutter and actuated by its
movements all substantially as and for the purposes herein described and shown in
the accompanying drawings.
Fourth. The construction of light proof carriers or envelopes of combined paper
and cloth for portably carrying photographic dry plates all substantially as herein
described and illustrated by Figure 7 of the accompanying drawings.
Dated the 9th do of 100
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.