Improvements in Portable Dark Rooms or Boxes for Photographers.
Year: 1894

page_text: Date of Application, 10th Apr., 1894-Accepted, 25th May, 1894
COMPLETE SPECIFICATION.
Improvements in Portable Dark Rooms or Boxes for Photographers.
I ARTHUR DAVIES FITZ RANDOLPH, Publisher and Bookseller, of 36 Wall
Street, New York in the United States of America, 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 relates to a portable dark room or box for photographers by means
of which the essential steps necessary to develop and fix a picture after exposure
of the plate in the camera can be performed on the spot, thereby obviating the
necessity and annoyance occasioned by the general practice of accumulating a
number of plates after exposure and carrying them to a dark room and developing
them.
This invention aims to provide a dark room for the aforesaid purposes which
will be light, cheap, and fold into a compact form so as to be readily carried
without materially adding to the weight and bulk of the ordinary outfit for out
door work.
The invention consists of a folding frame of peculiar arrangement to form a
supporting structure for the textile fabric forming the sides of the device, and
having colored glass in the top to exclude the acting rays of light and permit the
operator to observe the process of handling the developing tray, the plate holder,
and the plate when transferring the same from the plate holder to the developing
tray in which it is developed and fixed and having cuffs through which the hands
of the operator are thrust when handling the plate, said cuffs having contractible
wrist bands to fit close to the wrist to exclude rays of light.
The improvement further consists in the novel features and the peculiar
construction and combination of the parts which will be hereinafter more fully
described and claimed and which are shown in the annexed drawing, in which;
Figure 1 is a perspective view of a dark room or box embodying my invention,
part of the top or colored glass being broken away to show the inner end of
a cuff.
Figure 2 is a cross section on the line 1-1 of Figure 3, showing a developing
tray in position, and showing the door in the bottom dropped, in dotted lines.
Figure 3 is a horizontal section on the line 2 2 of Figure 2, showing a developing
tray in position at one end, said tray having a portion broken away.
Figure 4 is a detail perspective view of the lower end of one of the supports
showing the relative position of the spring for holding the support in an elevated
position.
The dark room or box is composed of a bottom N, a top A, folding corner
supports E, a textile fabric H constituting the ends and sides, and cuffs K.
The bottom N may be of wood or other suitable substance, and is provided in its
edge with a groove to receive the lower edge of the fabric H and a wire band J,
which latter serves to secure the lower edge of the fabric in the said groove.
A door M is provided to close an opening in the said bottom N, through which a
developing tray and plate holder is passed into the dark room or box. This door M
is hinged at one end and is secured at its free end when shut by any well known form
of catch m.
The top is composed of a colored glass A, either ruby, orange, red or other color
which will exclude the actinic properties of rays of light, and a frame U. This
frame is constructed to embrace the edges of the glass A and is preferably
constructed of a strip of sheet metal which is bent upon itself between its edges, so
as to receive the edge of the glass between the parallel or folded portions.

page_text: A corresponding frame or strip I is attached to the inner or under side of the
frame O and has the upper edge of the fabric H clamped between it and the
frame O, as most clearly shown in Figure 2. The folding supports E are secured
at their ends to the bottom N and the frame of the top by pivotal or hinge
connections. These supports have the pivotal connections between their ends so
disposed as to admit of the top folding close upon the bottom N. The parts
composing a folding support are connected by a rule joint so that when the
supports are opened or extended the parts will be held rigidly against outward
movement when in alignment. These supports are constructed to fold inward so
as to be comprised between the top and bottom when the device is folded. For
lightness and strength the supports will be formed from strips of sheet or plate
metal which is bent between its edges so that the bent portions will stand about at
right angles to each other, giving the supports an L-shape in cross section.
A coil spring G is provided for each support, and is attached to the bottom N in
any convenient manner, preferably by having the bent end of arm 9' driven into
the said bottom. The other end or arm of the spring engages with the support and
in the preferable form of construction is seated in a depression f near the lower end
of the support. These springs G exert a pressure on the said supports to force the
same open and hold them in a distended position. Obviously, when folding the
device these springs G will have their tension increased to such a degree as to
materially assist in distending the device when being opened or set up for use.
The textile fabric H will be of suitable material to exclude light and fold without
cracking and not be rendered unfit for use from moisture, and will be secured at
its top and bottom edges, respectively, to the top and bottom in any desired
manner preferably by the means herein set forth. The fabric will be stretched
around the corner supports E and supported thereby at the angle when the device
is set up for use.
The cuffs K are located on opposite sides of the device and are secured at their
inner ends to the fabric H. The outer ends of the cuffs are expansible to snugly
encircle the wrists of the operator so as to exclude rays of light. Rubbers or
elastic band L are applied to the outer ends of the cuffs to draw said ends together
and obtain a close fit thereof on the wrists of the operator.
To use the invention the same is set up or distended, substantially as shown in
Figures 1 and 2, and will be suitably supported so that the door M can be opened
downward without interference to freely admit of a developing tray and plate
holder being passed into the dark room or box through the opening provided in the
bottom of the device. Any form of developing tray P may be employed. After
the developing tray and plate holder have been placed in the dark room or box, the
operator thrusts his hands through the cuffs and removes the plate from the plate
holder and places the same within the developing tray P, where it is developed and
fixed in the ordinary manner. The process of manipulating the plate holder and
plate can be observed through the glass top. When the device is not in use it can
be folded in a compact form by breaking the joints of the corner supports and
folding the top upon the bottom. The cuffs being of textile fabric can be pushed
within the structure or folded in any desired manner found most convenient.
Having now particularly described and ascertained the nature of my said inven
tion and in what manner the same is to be performed, I declare that what I
claim is
1. A folding portable dark room for photographers, consisting of a top and
bottom frame, flexible sides connected at their top and bottom edges with the said
top and bottom frames, corner supports connected midway of their ends by a rule
joint and hinged at the ends, respectively, to the said top and bottom frames and
arranged to stiffen the said flexible sides at the angles when the structure is in use,
said supports having depressions of near one of the binged ends, and coil springs
having arms 9 seated in the said depressions and having arms gl secured to the
contiguous frame, substantially as set forth.

page_text: 2. The folding portable dark room for photographers herein set forth, consisting
of a bottom having a downwardly opening door and grooved in the edge, a top
frame having grooves in its inner edges a frame I secured to the said top frame,
flexible sides having the top edge clamped between the top frame and the frame I,
and having the lower edge held in the said grooved edge of the bottom by a clamp
wire, and having flexible cuffs on the opposite sides provided with contractible
wrist bands, folding corner supports connected midway of their ends by rule joints
and hinged at their ends, respectively, to the top and the bottom and adapted to
stiffen the flexible sides when the structure is in use, and springs to hold the corner
supports distended, as set forth.
Dated this 10th day of April 1894.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.