Improvements in or appertaining to Dark Chambers for Photographic Purposes.
Year: 1896

page_text: Date of Application, 29th Jan., 1896
Complete Specification Left, 24th Oct.. 1896-Accepted, 24th Dec., 1896
PROVISIONAL SPECIFICATION.
Improvements in or appertaining to Dark Chambers for
Photographic Purposes.
A communication by HEINRICH HOFMANN, of Offenbach on Main, in the Empire
of Germany, Manufacturer.
I, GEORGE CECIL DYMOND M. Inst. M.E. of The Agency for Foreign Patent
Solicitors 6, Lord Street Liverpool and 6, Bank Street, Manchester, both in the
County of Lancaster, 118 New Street Birmingham in the County of Warwick
and 31 High Holborn in the County of Middlesex Patent Agent do hereby declare
the nature of this invention to be as follows:-
Although amateur photography has so largely increased in recent years owing
to the great advance in chemistry and technology, there still remains a great
drawback for the amateur.
It is very often extremely annoying, more particularly for those amateur or
other photographers who are travelling, not to know whether any given exposure,
which could if necessary be immediately repeated has succeeded or not.
The desire therefore very often arises for some meaus for rapidly developing the
plate exposed.
Hitherto however there was no portable dark chamber existent which enabled
this requirement to be fulfilled.
This drawback is removed by the object of the present invention, by which a
dark chamber is provided, the working of which is thoroughly sure and very
convenient and which may also be collapsed, and thus rendered very portable enabling
it to be universally employed.
An essential condition of such an apparatus is, that it occupies as small a space
as possible. This improved dark chamber is so arranged that the whole person of
the operator does not enter therein, but only his arms, whilst he can still see well
all that takes place inside.
This improved dark chamber consists essentially of two parallel walls which are
connected with one another by means of a bellows bag, or the like.
In the front wall there is a suitable opening closed by a coloured disc, and
further to the right and left of this opening two holes for the passage of the arms
of the operator.
These two holes are each provided with a sleeve projecting inwardly into the
chamber, which sleeves at their inner ends are drawn tightly round the wrists of
the operator and are thus closed against the admission of light from the outside.
The rear wall of the chamber has also an opening covered by a coloured plate or
disc of suitable material.
In order to utilise the apparatus, it is first expanded, then the bottom board,
which has been folded up in the inside against the rear wall, is let down and
supported or engaged at both sides or at the top on the edges of the front wall.
The whole apparatus is next placed on a table, in the daytime with the rear disc
against a window, or the like, and at night in proximity to a lamp or other suitable
light.

page_text: By raising the front plate or slide, the exposed plates, developers and the like
may be inserted in the chamber.
The plate or slide is then again closed, the arms are passed through the holes
hereinbefore mentioned and secured in the sleeves and the person is then in a
position to develop, fix, or otherwise treat the plates in the ordinary manner, as
everything can be inspected and examined through the front disc or plate.
After use the whole apparatus may be collapsed, and inserted in a suitable big
or pocket, and thus becomes conveniently portable.
Dated this 28th day of January 1896
Improvements in or appertaining to Dark Chambers for
Photographic Purposes.
A communication by HEINRICH HOFMANN, of Offenbach on the Main, in the
Empire of Germany, Manufacturer.
I, GEORGE CECIL DYMOND, M. Inst. M.E., of The Agency for Foreign Patent
Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester both in
the County of Lancaster, 118 New Street, Birmingham, in the County of
Warwick, and 322, late 31, High Holborn in the County of Middlesex, Patent
Agent, 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 :-
Although amateur photography has so largely increased in recent years owing to
the great advance in chemistry and technology, there still remains a great drawback
for the amateur.
It is very often extremely annoying, more particularly for those amateur or
other photographers who are travelling, not to know whether any given exposure,
which could if necessary be immediately repeated, has succeeded or not.
The desire therefore very often arises for some means for rapidly developing the
plate exposed.
Hitherto however there was no portable dark chamber existent which enabled
this requirement to be fulfilled.
This drawback is removed by the object of the present invention, by which a
dark chamber is provided, the working of which is thoroughly sure and very
convenient and which may also be collapsed, and thus rendered very portable,
enabling it to be universally employed.
An essential condition of such an apparatus is that it must occupy as small a
space as possible. This improved dark chamber is therefore so arranged that the
whole person of the operator does not enter therein, but only his arms, whilst he
can still see well all that takes place inside.
In the accompanying drawing,
Figure 1 is a front view;
Figure 2 a vertical section; and
Figure 3 a horizontal section of this improved chamber; and
Figure 4 a side view of the chamber when collapsed.
This improved dark chamber consists essentially of two parallel walls a and b
which are connected with one another by means of a bellows bag, or the like !.
In the front wall a there is a suitable opening d closed by a coloured disc c and

page_text: further to the right and left of this opening two holes e and f for the passage of
the arms of the operator.
These two holes are each provided with a sleeve g and h projecting inwardly into
the chamber, which sleeves at their inner ends are drawn tightly round the wrists
of the operator and are thus closed against the admission of light from the outside.
The rear wall of the chamber has also an opening i covered by a coloured
plate or disc of suitable material.
In order to utilise the apparatus, it is first expanded, then the bottom board k
which has been folded up in the inside against the rear wall b is let down and
supported or engaged at both sides or at the top on the edges of the front wall a.
A hooked rod m pivoted on the front plate a is then turned up into a horizontal
position and its hooked end inserted in an eye on the rear wall b thus holding the
whole rigidly together.
The whole apparatus is next placed on a table, iu the daytime with the rear
disc i against a window, or the like, and at night in proximity to a lamp or other
suitable light.
By raising the front plate or slide c, the exposed plates, developers and the like-
may be inserted in the chamber.
The plate or slide is then again closed, the arms are passed through the holes e
and hereinbefore mentioned and secured in the sleeves and the person is then in
a position to develop, fix, or otherwise treat the plates in the ordinary manner, as
everything can be inspected and examined through the front disc or plate c.
After use the whole apparatus may be collapsed, as shown in Figure 4, and
inserted in a suitable bag or pocket, and it thus becomes conveniently portable.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
An improved collapsible portable dark chamber, consisting of two walls (a and b)
connected with one another by a bellows bag or sack and an inner board hinged to
the front wall, both walls having openings provided with coloured plates or discs
and the front wall (a) having also two openings provided with sleeves or the like
to admit the arms, the inuer hinged board being adapted to be turned down in.
order to fix up the whole apparatus, substantially as herein before described and
shown in the accompanying drawing.
Dated this 23rd day of October 1896.
WM. P. THOMPSON & Co.,
Agents.