An Improved Apparatus for the Development of Photographic Pictures.
Year: 1891

page_text: Date of Application, 15th Aug., 1891-Accepted, 24th Oct., 1891
COMPLETE SPECIFICATION.
An Improved Apparatus for the Development of Photographic
Pictures.
We, OLE PEDERSEN OLVIK, Photographer, and HANS OLSEN MORKEN,
Tinman, both of Stördalen, in the Kingdom of Norway, do hereby declare the
ature 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 :-
Our invention relates to apparatus comprising a bath and dark tent for the
levelopment of photographs whereby the sensitive plate is not exposed to any
njurious light, nor to the action of extraneous substances, as the plate is not
ouched during the development.
8
Figure 4 is an elevation of a device hereinafter described to be used in connection
with the bath, and
Figure 5 is a perspective view of the dark tent.
The developing bath which can be made of zinc, india-rubber or other suitable
material consists of a frame a having a plate 6 of glass, gelatine or the like secured
water-tight in its bottom and a similar plate e sliding in its top. The chamber thus
formed is closed by a door d covered with india-rubber e, so that by means of the
fastening it can be caused to fit quite water-tight over the end of the frame.
The plates and are protected by sheet metal covers and c¹ sliding over them.
The developing liquid is poured into the chamber a through a funnel and a tube h
which is bent at an angle to prevent the admission of light and after being used it
is discharged through a tube i also bent at an angle for the same purpose and
provided with a valve k.
The inspecting device Figure 4, which is only employed when developing by a
dull light, consists of a frame 1, which exactly fits in the grooves for the plate c
when the latter is removed, and of the casing m terminating at the top in a
rotatable tube shaped to fit the eye of the operator; the opening between m
and n can be closed by the shutter p, moved from without by the crank-handle o.
The dark tent represented in Figure 5 has, when extended, as shewn in the
drawing, the shape of a case 9, 7 and is constructed of light water-proof cloth on
the same principle as an umbrella, the ends of the case being stretched out by
ribs hinged to runner notches ¹ sliding along a sticks and kept in position by
stop-springs s'. The ends fold inwards when closing the tent, while the longi-
tudinal parts q" will lie wrapped round the middle part of the stick, the whole
having then the appearance of a closed umbrella, with handle s" and ferrule s
Over the two manipulating holes in front of the tent, mufflers t, t are placed, having
elastic bands which fit tightly over the wrists of the operator when he inserts his
hands. In the front of the tent is also an opening ", provided with an elastic band
that closes it. v is a red-coloured glass-plate, through which the inside of the tent
may be inspected, and w is a piece of red translucent cloth, which admits the
necessary light. is a piece of some dark sleazy cloth, serving to cover the head
of the operator when working in the tent.
The apparatus is made use of in the following manner:-
The tent having been extended by putting the hands through the mufflers t, t
and pushing the runner notches, outwards, and the case containing the photo-
graphic plate having been placed in the tent the developing bath a is passed
through the opening u into the tent; the opening u fitting light-tight while this is

page_text: being done. The operator then, with his hands in the mufflers t, t, takes the
photographic plate out from the case and passes it through the door d into the bath
which he then tightly closes by means of the fastening, and withdraws it from the
tent. The developing liquid is now as soon as possible poured through the funnel
into the bath until it reaches the level of the funnel, and the bath is then well
shaken. By drawing the covers and c aside it can be seen both by daylight and by
artificial light if the plate is sufficiently developed and, if it is, the discharge
tube i, is opened to let out the liquid, the fastening fof the door is unscrewed,
and the photographic plate is withdrawn and immediately placed in the fixing-bath,
which by daylight should be covered with a dark cloth.
The inspecting device which is only employed when working in a dull light
enables the operator the clearer to see the developed plate. The device takes the
place of the glass-plate e after its removal, and the bath with the device is now
placed against the light, while the operator keeps the tube to his eye and opens
the shutter p, which must be always closed, when the device is not being used
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that
what we claim is :-
1. A developing bath consisting of a frame a with a fixed transparent coloured
plate 6 in the bottom and a similar sliding plate c in the top, both protected by
sliding covers b, c, a door d with india-rubber covering e held in a closed position
by a fastening fand a funnel g, h and outlet-tube i, k, substantially as and for the
purpose set forth.
2. The use in combination with a developing bath such as is mentioned in Claim 1,
of an inspecting device consisting of a frame 1, case m, tube n and shutter p with
crank-handle o, substantially as and for the purpose set forth.
7'
3. The use in combination with a developing bath such as is mentioned in Claim 1,
of a dark tent constructed on the same principle as an umbrella with ribs and
runner notches held in position by stop springs s¹ upon the sticks having a
handles and a ferrule s, the tent being further provided with mufflers t, t, an
opening u, a transparent plate v, a translucent plate w and a cloth x, substantially
as and for the purpose set forth.
Dated the 15th day of August 1891.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.