Improvements in Method of and Apparatus for Developing, Toning and Fixing Photographs.
Year: 1897

page_text: Date of Application, 22nd Sept., 1897-Accepted, 19th Mar., 1898
[Communicated from abroad by ARTHUR SCHWARZ, of Berlin-Schoneberg,
Germany, Manager of Works]
Improvements in Method of and Apparatus for Developing, Toning
and Fixing Photographs.
I, GUSTAVE ADOLPHE DE KATOW, of 7, Featherstone Buildings, Holborn, London,
W.C., Engineer, Linguist, and Patent Expert, 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:--
In the manufacture of photographs the sensitized paper is fed through the several
baths for developing, toning and fixing the pictures.
With this operation as hitherto carried out, only one and the same toning of
the photographs is obtained, because the strip of paper is continually fed at a
uniform speed through the several baths.
I have devised a new apparatus, whereby the treatment of the strip of sensitized
and exposed paper is also carried out in a continuous manner, but which is so con-
structed that it enables me to obtain different shades in the toning of the photo- -
graphs.
I have attained this purpose by devising arrangements enabling me to shorten
or extend at will the period during which the photographs are treated in the baths;
either by increasing or decreasing the speed of feeding of the paper through the
baths, or by immersing the loops of paper more or less deep into the baths, whereby
the speed of the travel of the paper remains unchanged.
I have illustrated my new apparatus in the annexed drawings, making a part of
this specification, same letters of reference being used for the same parts in the
several views, and wherein :-
Fig. 1 shows an apparatus, wherein the toning of the photographs can be
regulated by changing the speed of travel of the paper through the baths, and
also embodying a device enabling me to prevent the loss of a part of the paper,
when same should tear in the course of the process.
Fig. 2 shows a plan view on a larger scale of the mechanism for changing the
speed of travel of the paper;
Fig. 3 shows a sectional front view of a bath embodying a device to change the
depth of immersion of the paper.
Fig. 4 shows a sectional side view of the same bath, the paper being immersed
very deep;
Fig. 5 shows a similar view with a very shallow immersion of the paper;
Figs. 6 and 7 show details of construction;
Fig. 8 shows a sectional front view of a bath equipped with a modified construc-
tion of the device for regulating the depth of the immersion of the paper;
Figs. 9 and 11 show sectional views of other modified constructions of baths
whereby the depth of immersion of the paper can be regulated at will by changing
the level of the solution of the bath,

page_text: Fig. 10 is a plan view of the bath shown in Fig. 9.
The exposed paper P is as usual wound upon the reel R and is fed over the
feeding rolls W, WI, W, etc. through the baths I, II, III, and IV, the loops of
paper being weighted down in each bath by means of the small rolls r.
The feeding rolls W, W, W2, etc. are rotated at uniform speed by the shaft L
by means of worin gears N.
At its end the shaft L carries a disk a, in frictional contact with a friction
roller brigidly mounted upon the shaft B, so that the shaft L is rotated by the
shaft B. This shaft B is adapted to be moved in an axial direction by means of
the hand wheel C (Fig. 2), so as to shift the point of contact of the friction roller b
and the disk a. It is obvious that the further the roller b is removed from the
centre of disk a, the slower the rotation of the shaft L will be and vice versa.
These changes in speed may of course be effected gradually by means of the
mechanism described, and by these means I am enabled perfectly to regulate the
speed of the travel of the paper through the baths.
The shaft B is rotated by a belt laid over the stepped pulleys D, D¹, D2, as
shown in Fig. 2, and this arrangement affords another means roughly to regulate
the time of treatment of the paper. But as each rate of speed as obtained by the
shifting of the belt can be further minutely changed by means of the shifting
of the point of contact between roller b and disk a, the mechanism described affords
the means exactly to regulate the speed of the travel of the paper.
If it should be desired not to change the speed of travel of the paper, or if besides
this it should be preferred to use another means for changing the toning of the
photographs, I make use of the arrangement illustrated in Figs. 3 to 7.
To this end the opposite walls of the receptacles are provided.with rails, that are
extended parallel up to the ceiling of the work-room. These rails should be formed
so as to prevent a lateral motion of the rollers el running thereon, and should be
preferably of the form shown in cross section in Fig. 6. A frame E, preferably
of the form shown in Fig. 3, and provided at its four corners
rollers e corresponding in shape to the rails e is adapted to be moved vertically
up and down between said rails. This operation is conveniently performed by
means of a counter-weight Q.
with
The frame E is provided at its lower end with a guide roll r. adapted to guide
the paper in the bath. As shown in Fig. 6 the journals of the roll r are housed
in slots in the downward extending projections, of the frame E and are kept in
place by pins 3. A clamping device F, the cheeks f¹, f2 (Fig. 7) of which clasp
the rail and are clasped together by the screw f3 prevent any unintentional
motion of the frame E. The clamping device F is hinged to the frame E and is
moved back in the position shown in dotted lines in Fig. 3, if the frame is to be
taken out of the rails.
The frame and the rails are made of metal, hard rubber or any other suitable
material which is not affected by the baths. The time during which the paper
is submitted to the action of the bath, if it travels at uniform speed, depends upon
the length of the travel through the bath. With the device just described the
length of this travel can be varied at will by shifting the position of the frame.
Fig. 4 shows the frame lowered into the bath and Fig. 5 shows it in a raised position.
In this way any desired shade of toning can be obtained, and if the position of
the frame for a certain tone is once ascertained, all pictures will be uniformly
toned.
The arrangement described embodies a superstructure which in some cases may
be undesirable, and which is done away with in the modification illustrated in
Fig. 8.
The loop of paper depends into the baths from the feeding roll W, and is
weighted down by the guide roll r. The axle of roll is housed in slide pieces,
that slide on the rail e when the roll r is displaced.
Close to the slide pieces 5, which may of course be substituted by small rollers,
are attached cords s and s¹ by means of a loop or a ring as shown, so that when

page_text: the two cords s and s¹ are pulled down at the same time and with the same force,
the roll is lowered parallel to the travel of the paper. The downward motion of
the roll in this construction is effected by the weight Q acting upon the cords s
and s¹, while the upward motion of the roll is effected by the upward pull of the
strip of paper travelling through the bath. For this purpose, the cord 's is passed
over the bottom roll and then passes upward over the roll X, and is then passed
between the clamping rollers y¹ y² to the weight. The cord s¹ first passes around
roll thence to roll, and thence parallel to cords to the weight Q. If the
weight Q and the weight of the guide roll r are sufficient to overcome the upward
pull of the strip of paper, moved by the feeding roll W, the weight Q¹ and the
cords ss will pull the guide roll downward as soon as these cords be released.
As in this case the pull at both ends of the guide roll is entirely the same said
roll will be lowered and remain parallel to the axle of the feeding roll W.
In order to secure the guide roll r at any desired height, the cords s, s¹ are passed
between clamping rollers y', y, the roller y¹ having a fixed axle, while the axle
of roller y is movable in the oblique slot z.
If the rolly is pulled upward, so that its axle becomes located in the upper
part of the slot z, the clamping action on the cords. s, s¹ is released, the weight Q¹
moves downward and pulls the guide roll rand consequently the loop of paper
deeper into the bath.
If the roller is then released, it will pull back by its own weight the
cords s, s¹, and owing to its oblique slot it clamps the cords immediately against
roller y', so that the desired adjustment is obtained.
If, on the contrary, the paper is desired to become further immersed, it is only
necessary to lift the weight Q', and the roll r will then be raised by the pull of
the paper, and as the cords will thereby move in the reversed direction, the clamp-
ing rollers y, y³ are automatically opened.
As soon as the desired position is reached, the weight Q¹ is again released and
under the influence of its weight, the clamping action of the rollers y¹ y² is at once
restored.
It is obvious that the movement of the guide roll r may be obtained by other
means, but these are merely modifications the object in view being to adjust the
roll by a downward pull.
As already stated, the shade of toning may also be varied by changing the level
of the solution in the bath, it being obvious that by such change the travel of the
paper through the solution may be extended or shortened. This arrangement,
which also presents the advantage that the moist paper which is liable to tear is
not shifted in its position is illustrated in Figs. 9, 10 and 11.
The bath I has at its four corners vertical, perforated pipes 9 connected by
pipes g. One of these pipes is connected by a suitable pipe G with an elevated
receptacle H containing the solution for the bath.
By opening the cock h, provided in the feed pipe G, the bath I can be filled so
far that it requires a certain pre-determined time for the paper to travel through
said bath so as to procure the required toning.
Now, if for another shade of toning, the duration of the travel is to be shortened,
the attendant turns the spindle K downward and so pushed down the levers k,
that are connected by a rod 1, thereby raising the valves L resting on the other
end of the levers 7, so that the solution can flow out of the bath I.
As soon as the solution has reached the desired level, the attendant turns the
spindle K upward, so that the valves L will automatically close under the impulse
of their own weight and the pressure of the liquid.
The liquid drawn from the bath I flows through a gutter m to a suitable recep-
tacle (not shown) from which it is again conveyed by any suitable means to the
elevated tank H.
In the construction shown in Figs. 10, no valves are required.
One of the vertical, perforated pipes g is extended through the bottom of the
receptacle I, and is connected by means of a hose with the feeding tank H. This

page_text: tank H is not stationary but is suspended from a rope N running over rollers n,
in such way that it can be moved up and down.
It is obvious that according to the higher or lower position of the tank H in
regard to the bath I, the level of the solution in the latter will be higher or lower.
In all the arrangements thus far described, it is quite possible that the moist
paper may tear in the course of its travel through the baths.
If the paper tears, which notwithstanding all possible precautions, is apt to occur
from time to time, as it becomes thoroughly moistened by the solutions, the opera-
tion must be interrupted in order to fasten together the two ends.
During this time the travel of the paper is interrupted, so that the loop of paper
in the toning solution remains subjected to the action, which in most cases is too
long, so that this length of paper is spoiled.
This more or less frequent loss may be avoided by providing the driving shaft
for the feeding rolls with a device enabling me to withdraw the lengths of paper
located in the toning and developing baths, whenever the continuous operation
of the apparatus should be interrupted in consequence of a break of the endless
band of paper. This arrangement is illustrated in Fig. 1.
'
At any suitable place, preferably behind bath 11, which contains the toning
solution, the shaft L is cut and the two ends are connected by an easily operating
coupling or clutch o. The right hand end of the shaft L is moreover provided
with a crank S.
Now if the band of paper becomes torn, for instance after passing through
bath 11, the belt d is shifted to the idle pulley and the coupling o is thrown out
of gear by means of the lever o¹, or by any other suitable device.
The right hand side end of the shaft L is now turned by means of the crank S
with equal speed in the opposite direction and the end of the strip of paper is
taken hold of. It is obvious that in this way the paper in the baths 1 and 11 will
be withdrawn from same with the same speed as if the continuous operation had
not been interrupted. Consequently this length of paper which would otherwise
have been lost is now saved.
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
1. A method for developing, toning and fixing an endless band of photographic
paper, whereby the treatment in the bath may be so timed as to obtain any desired
shade of toning, substantially as described.
2. In an apparatus of the class described, the combination of a series of baths
containing the necessary solutions, with means for regulating the time of the
treatment of the paper in the baths so as to obtain any desired shade of toning
substantially as described and set forth.
3. In an apparatus of the class described, the combination of a series of baths,
with means for feeding the paper through said baths at any desired rate of speed,
substantially as and for the purpose described and set forth.
4. In an apparatus of the class described, the combination of a shaft L driving
the feeding rolls for the paper, with a disk a in frictional contact with and rotated
by a friction roll' b, so that the speed of the shaft L may be changed by displacing
the point of contact, between the disk a and the roll b substantially as and for the
purpose described and set forth.
5. In an apparatus of the class described, the combination of a divided shaft with
a coupling adapted quickly to connect or disconnect the two parts of the shaft,
the part of the shaft located over the developing and toning baths being equipped
with means to rotate it independently of the other part of the shaft, substantially
as and for the purpose described and set forth.
6. In a bath for treating photographic paper, the combination of the feeding
rell with a guiding roll, and means for raising or lowering the guiding roll in
the bath, substantially as and for the purpose described and set forth,

page_text: 7. In an apparatus of the class described, the combination of a bath with an
elevated feeding receptacle for same, and means for regulating the afflux and the
efflux of the solution to and from the bath, substantially as and for the purpose
described and set forth.
8. In an apparatus of the class described, the combination of a bath with a
movable feeding tank, so that the level of the liquid in the bath is determined by
the relative position of the feeding tank, substantially as and for the purpose
described and set forth.