Improvements in Apparatus for Changing Sensitized Plates for Photographic Cameras.
Year: 1891

page_text: Date of Application, 10th July, 1891
Complete Specification Left, 11th Apr., 1892--Accepted, 14th May, 1892
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Changing Sensitized Plates for
Photographic Cameras.
We, WALTER EDMUND KERSLAKE of 47 Garrick Street, Engineer, and
PETER WHITE JOHNSON of 5 West Road, Elm Park, Ullet Road, Engineer,
both of Liverpool in the County of Lancaster, do hereby declare the nature of this
invention to be as follows:-
-This invention has reference to a changing bag and means for attaching the
same to the dark slide of a camera so that sensitized plates can be transferred
from the bag to the slide, and rice versa, and the object of the invention is to
ensure the bag being closed so as to exclude all light from the plate when the latter
is in the bag, and also to provide means for attaching the bag to the dark slide,
such that the plate can be readily transferred from the one to the other without
admitting any light thereto.
We provide a bag sufficiently wide to contain the intended plate, but somewhat
longer than the latter; the bag is made of any suitable material which is quite
opaque to actinic light, we find waterproof cloth or thin sheet indiarubber suitable
for the purpose.
We line the interior of the mouth end of the bag with velvet, plush, or other
pile material, the lining extending a little over the edge of the plate when the latter
is within the bag, so that there may be no liability of the plate catching the edge
of the material as it is being withdrawn.
At a short distance from the mouth of the bag but between the mouth and the
edge of the plate, we attach a strip of metal or other suitable material to each of
the opposite sides of the bag; these strips are nearly as long as the width of the
bag, and placed preferably between the pile material and the outer material of
the bag; it will be seen that when a rubber band is stretched round the bag and
over the strips, the pilo material lining the bag is brought into close contact and to
closes the bag and excludes the light.
In order to more effectually exclude the light, we corrugate the strips longi-
tudinally that is to say the corrugations are parallel to the mouth of the bag and
they are so arranged as to interlock; and in order to stiffen the bag, we attach a
metallic frame to the bottom and two sides, the section of the frame is preferably
"U" shaped the concave side being inwards, this also serves to protect the edges
and corners of the bag against wear.
The dark slide which fits the camera in the usual way and which has an ordinary
sliding door to expose the plate, is provided with a rectangular tube, corrugated
transversely, over which the mouth of the bag stretches and through which the
olate is passed into a groove in the slide; the corrugations serving to more
effectually exclude the light and to prevent the bag slipping off.
The mode of using the bag is as follows;-
A sensitized plate is placed in the bag in a dark room, and the bag closed by
placing a rubber band over the strips. When it is desired to place the plate in the
lark slide, the mouth of the bag is stretched over the corrugated tube and the
ubber band is removed from over the strips and placed round the tube (or two
ubber bands may be used), the plate is then transferred from the bag to its
osition in the dark slide and the exposure made, after which the plate is transferred
ack to the bag,
The dark slide may if desired be fitted with ground glass for focussing, said

page_text: glass being arranged to move back to admit the plate; the dark slides may also be
made single or double as preferred.
The mouth of the bag may be corrugated so as to form a better joint with the
corrugated tube, and metallic springs may be substituted for the rubber bands.
The portion of our invention relating to the corrugating of the bag and tube is
also applicable to changing boxes and other devices for changing sensitized plates.
Dated this Ninth day of July 1891.
SLOAN & LLOYD BARNES,
Castle Chambers, 26, Castle Street, Liverpool, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Changing Sensitized Plates for,
Photographic Cameras.
We, WALTER EDMUND KERBLAKE, formerly of 47 Garrick Street, but now
of 37 Bloom Street, Engineer, and PETER WHITE JOHNSON of 5 West Road,
Elm Park, Ullet Road, Engineer, both of Liverpool in the County of Lancaster,
do horeby 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 a changing bag and means for attaching the
same to the dark slide of a camera so that sensitized plates can be transferred from
the bag to the slide, and vice versa, and the object of the invention is to ensure the
bag being closed.so as to exclude all light from the plate when the latter is in the
bag, and also to provide incans for attaching the bag to the dark slide, such that
the plate can be readily transferred from the one to the other without admitting any
light thereto.
In the accompanying drawings which illustrate our invention, Figs. I and II
show the changing bag in position on the dark slide, Fig. I being a section
on A, A, of Fig. 11 and Fig. 1 being an elevation; Fig, III is a section on B, B,
of Fig. II Fig. IV is a longitudinal section, to an enlarged scale, showing the
mouth of the changing bag fitted with corrugated strips; and Figs. V, VI and VII
are detail views of a corrugated clip for closing the mouth of the bag; Figs. V
and VI being sections on C, C, and D, D, respectively, of Fig. VII.
Throughout the drawings similar parts are indicated by the same reference
figures, and in the case of sections, the direction in which they are viewed is
indicated by the small arrows placed adjacent to the letters denoting the plane of
section.
·
We provide a bag 1 sufficiently wide to contain the intended plate 2, but some-
what longer than the latter; the bag is made of any suitable material which is
quite opaque to actinic light, we find waterproof cloth or thin sheet indiarubber
suitable for the purpose..
We line the interior of the mouth end of the bag with velvet, plush, or other
pile material 3, the lining extending a little over the edge of the plate when the
fatter is within the bag, so that there may be no liability of the plate catching the
edge of the material as it is being withdrawn.
At a short distance from the mouth of the bag but between the mouth and the
edge of the plate, we attach a strip of metal 4 or other suitable material to each of
the opposite sides of the bag; these strips are nearly as long as the width of the
bag, and placed preferably between the pile material and the outer material
of the bag it will be seen that when a rubber band is stretched round tho bag
and over the strips, the pile material lining the bag is brought into close contact
and so closes the bag and excludes the light.
In order to more effectually exclude the light, we corrugate the strips

page_text: longitudinally that is to say the corrugations are parallel to the mouth of the bag
and they are so arranged as to interlock.
This is shown in Fig. IV the corrugated strip 4' being shown attached to the
bag between the pile material 3 and the material of the bag 1. In some cases we
prefer to have the corrugated strips detached from the bag in which case they
assume the form of clips 4" as shown in Figs. V, VI and VII, the clip being
hinged at 5 and provided with a suitable tightening uut 6. It will be seen that
when the clips are placed over the mouth of the bag and tightened the latter is
very effectually closed.
In order to stiffen the bag, we attach a metallic frame to the bottom and two
sides, the section of the frame is preferably "U shaped the concave side being
inwards, this also serves to protect the edges and corners of the bag against wear;
the U tube is not shown in the drawings.
The dark slide 7 which fits the camera in the usual way and which has an
ordinary sliding door to expose the plate, is provided with a rectangular tube 8,
corrugated transversely, over which the mouth of the bag stretches and through
which the plate is passed into a groove in the slide; the corrugations serving to
more effectually exclude the light and to prevent the bag slipping off.
The rectangular tube 8 is preferably secured to the slide by means of turned
up nibs 9; the slide springs open enough to admit these nibs and on being closed
the nibs enter the wood and are clinched over. In order to prevent the film of
the sensitized plate being scratched as it passes through the tube 8 two side strips 10
are provided to support the edges of the plate.
The mode of using the bag is as follows;-
A sensitized plate 2 is placed in the bag 1 in a dark room, and the bag closed
by placing a rubber band over the strips 4 or 4' or the mouth is closed by the
clips 4" (the strips or clips, as the case may be, have a slight initial curvature in
the length so as to ensure the central portions coming together). When it is
desired to place the plate in the dark slide, the mouth of the bag is stretched over
the corrugated tube 8 and the rubber band or clip is removed from over the strips
and placed round the tube (or two rubber bands or clips may be used), the plate is
then transferred from the bag to its position in the dark slide and the exposure
made, after which the plate is transferred back to the bag.
The dark slide may if desired be fitted with ground glass for focussing, said
glass being arranged to move back to admit the plate; the dark slides may also
be made single or double as preferred.
The mouth of the bag may be corrugated so as to form a better joint with the
corrugated tube, and metallic springs may be substituted for the rubber bands.
The portion of our invention relating to the corrugating of the bag and tube is
alse applicable to changing boxes and other devices for changing sensitized plates.
We are aware that prior to our invention changing bags have been used to
change sensitized plates and to suoh we make no broad claim.
Having now particularly described and ascertained the nature of our said inven
tion, and in what manner the same is to be performed, we declare that what we
claim is ;-
In apparatus for changing sensitized plates
;-
1. A changing bag the mouth of which is lined inside with a pile material and
provided with two strips which may be plain or corrugated, having a slight initial
curvature in their length and adapted to bring the pile material into close contact
when pressed together by an encircling elastic band or spring clip, substantially as
described and illustrated.
2. In combination with a changing bag the mouth of which is lined with a pile
material, the clips 4" which may be plain or corrugated and which are adapted to
bring the pile material into close contact when closed, substantially as described
and illustrated.

page_text: 3. A rectangular tube 8 having turned up nibs:9 for attachment to the dark
slide, and side pieces 10 to protect the film of the sensitized plate, and being
corrugated to secure a light tight connection with the changing bag substantially
as described and illustrated.
Dated this 9th day of Anril 1892.
SLOAN & LLOYD BARNES,
Castle Chambers, 26, Castle Street, Liverpool, Agents for the Applicants.