Improvements in or relating to the Printing and Development of Photographic Film.
Year: 1898

page_text: '
Date of Application, 14th June, 1898
Complete Specification Left, 14th Mar., 1899-Accepted, 20th May, 1899
PROVISIONAL SPECIFICATION.
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Printing and Development of
Photographic Film.
We, CECIL MILTON HEPWORTH, of 10, Lysias Road, Balham Hill, in the County
of Surrey. Agent, and CHARLES URBAN, of 5, Warwick Court, High Holborn, in
the County of Middlesex, Manager, Warwick Trading Company Limited, do
hereby declare the nature of this invention to be as follows:-
This invention relates to the printing and development of photographic film in
long strips or lengths such as are used for cinematograph pictures.
Hitherto there has been a lack of uniformity in the development of the different
related pictures of a series on a film, so that the moving picture produced by
such a series changes its tone when being exhibited, in a manner which is
unpleasing; moreover the development of such films, even though it be unsatis-
factory in the respect above indicated, has necessitated the expenditure of a con-
siderable amount of time and has involved manipulation of the film by hand.
According to the present invention the development of a strip or series of pictures
is effected mechanically in apparatus which ensures uniformity of tone and
quality in the finished product, shortens the duration of the time required for the
production of a finished film and renders it unnecessary that the film should be
touched by hand during the process.
...
With mechanical developing apparatus of the kind above referred to there may
be combined, according to this invention, a device for automatically printing the
positive film from the negative strip and delivering it to the developing apparatus,
the printing and developing apparatus being operatively connected in such a manner
as to ensure the desired movement of the film in each of them. In the following
description one construction of such a combination is described by way of example.
it being understood that the printing apparatus and the developing apparatus are
not of necessity always employed in company:-
A strip of negative film laid against a strip of positive film is fed in company
with the latter through a device of the cinematograph type in a step-by-step move-
ment, being exposed at a suitable aperture to light in the pauses of such
movement in order to effect the printing of the positive film. On leaving this
printing apparatus the positive film passes into and out of baths of developer,
water, fixing solution, alum, and glycerine or other agents, being received finally
upon a drum, on which it is taken away for drying. Or the film may be led from
the last of its baths through drying apparatus or over a drying table, and finally
wound upon drums for storage or for exhibition.
A convenient construction according to this invention is one in which sprocket
wheels or other devices capable of imparting motion to the film are arranged in
proximity to the baths, and geared to each other, and to the cinematographic
mechanism in the printing device if the latter is employed, the film being led
from the first roller or feeding device through a bath of developer, whence it

page_text: passes into a bath of water and onward by way of other feeding devices if such
be necessary, through the other baths in like manner. The dimensions of the
baths and the length of the loops or portions of film which at any moment occupy
them, are so arranged as to give the desired period of immersion in the various
baths to the film therein. Guide rollers or rods or other means may be employed
to enable these lengths or dimensions to-be-varied from time to time as required
to vary the action of development as may be necessary. Floats or valves, or
automatic apparatus operating upon the bird-fountain principle, may be employed
to maintain the level of the liquid in the various baths. Alarm apparatus to give
warning of accidental breakage of the film or of variation in the quantity or
quality of the treating fluids, may be employed in conjunction with the apparatus
above referred to.
Although baths are hereinbefore referred to, the film may be treated according
to this invention by other means capable of applying the treating agents to the
film in the desired order automatically to the successive pictures thereon for
periods of the desired duration, in suitable quantity. Moreover the printing
device hereinbefore referred to need not be of the step-by-step device described
by way of example, for the films may be subjected to light whilst receiving uniform
motion in company.
Dated this 14th day of June 1898.
BOULT & WADE,
Agents for the Applicants.
Improvements in or relating to the Frinting and Development of
Photographic Film.
We, CECIL MILTON HEPWORTH, of 10, Lysias Road, Balham Hill, in the County
of Surrey, Agent, and CHARLES URBAN, of 5, Warwick Court, High Holborn, in
the County of Middlesex, Manager, Warwick Trading Company Limited, 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 the printing and development of photographic film in
long strips or lengths such as are used for cinematograph pictures.
Hitherto there has been a lack of uniformity in the development of the different
related pictures of a series on a film so that the moving picture produced by
such a series changes its tone when being exhibited in a manner which is
unpleasing moreover the development of such films, even though it be unsatis-
factory in the respect above indicated, has necessitated the expenditure of a con-
siderable amount of time and has involved manipulation of the film by hand.
According to the present invention the development of a strip or series of pictures
is effected mechanically in apparatus which ensures uniformity of tone and
quality in the finished product, shortens the duration of the time required for the
production of a finished film and renders it unnecessary that the film should be
touched by hand during the process.
..
With niechanical developing apparatus of the kind above referred to there may
be combined, according to this invention, a device for automatically printing the
positive film from the negative strip and delivering it to the developing apparatus,
the printing and developing apparatus being operatively connected in such a manner
as to ensure the desired movement of the film in each of them. In the following
description one construction of such a combination is described by way of example,

page_text: it being understood that the printing apparatus and the developing apparatus are
not of necessity always employed in company:
A strip of negative film laid against a strip of positive film is fed in company
with the latter through a device of the cinematographe type in a step by step move-
ment, being exposed at a suitable aperture to light in the pauses of such
movement in order to effect the printing of the positive film. On leaving this
printing apparatus the positive film passes into and out of baths of developer,
water, fixing solution, alum, and glycerine or other agents, lieing received finally
upon a drum, on which it is taken away for drying. Or the film may be led from
the last of its baths through drying apparatus or over a drying table, and finally
wound upon drums for storage or for exhibition.
A convenient construction according to this invention is one in which sprocket
wheels or other devices capable of imparting motion to the film are arranged in
proximity to the baths, and geared to each other and to the cinematographic
mechanism in the printing device if the latter is employed, the film being led
from the first roller or feeding device through a bath or developer, whence it
passes into a bath of water and onward by way of other feeding devices if such
be necessary, through the other baths in like manner. The dimensions of the
baths and the length of the loops or portions of film which at any moment occupy
them, are so arranged as to give the desired period of immersion in the various
baths to the film therein. Guide rollers or rods or other means may be employed
to enable these lengths or dimensions to be varied from time to time as required
to vary the action of development as may be necessary. Floats or valves, or
automatic apparatus operating upon the bird-fountain principle, may be employed
to maintain the level of the liquid in the various baths. Alarm apparatus to give
warning of accidental breakage of the film or of variation in the quantity or
quality of the treating fluids, may be employed in conjunction with the apparatus
above referred to.
The constructions of apparatus preferred for the carrying out of this invention
is illustrated in the accompanying drawings in which:-
Figure 1 is a side elevation of the combined printing and developing apparatus,
Figure 2 is a perspective view of the developing apparatus alone, and
Figure 3 is a diagrammatic plan of the main driving mechanism.
Like letters indicate like parts throughout the drawings.
The unexposed strip or length of film A to be, operated upon as hereinafter
described is carried by a drum A free to revolve upon a spindle or axle A², which
may be fixed by any convenient means to the framing B whereby the various
apparatus are supported. In the case of films to be used in cinematograph
apparatus, requiring edge perforations in the films, advantage is taken of these
perforations for manipulating the films whilst passing through the printing and
déveloping apparatus hereinafter described. For this purpose the films are passed
through any well-known form of perforator such as C, before their introduction to
the printing and developing apparatus. The perforator C is provided with a
pulley C driven by a cord C from a driving pulley C (Fig. 3) which is itself
mounted and driven in the manner described in connection with the description
of the driving mechanism of the whole plant. On one side of the perforater C
is mounted a roller D free to revolve on its supporting axle D₁, and having at
each end peripheral teeth or studs adapted to engage with the perforations made
by the perforator C in the film A. A toothed disc D² is provided at one end of
the roller D and an arm C+ reciprocated by an eccentric C connected with the
pulley C of the perforator C, engages with the teeth of the disc 12 by means of
a pawle and thus revolves the roller D a given amount at every reciprocation.
A guide roll E is made to bear upon the film as it passes over the roller 1) in
order that the film A may be kept in proper engagement with the teeth d. The
guide roll E is carried by an arme (similarly to the guide-rolls hereinafter referred
to in connection with Figure 2) pivotted to any convenient portion of the frame B
and bears upon the surface of the film by its own weight. A second guide-roll Et

page_text: similarly mounted on an arm e' is pivotted at e² to a portion of the frame B and
is urged against the film A by a spring e. A guide-roll E also spring controlled
serves to steady the travelling film A at a point where it leaves the perforating
apparatus to pass on to the printing apparatus. On the opposite side of the
perforator to that on which the roller D is mounted a tension device F' of any
well-known form, either gravity or spring-controlled, is provided in order that
the film A may be kept taut whilst passing through the perforator C. Rollers G
are provided where ever it is necessary to carry the film round any angles, so that
the film may easily pass round the angles and may not be scratched in so doing.
In order that scratching of the film may still further be obviated any guide-rolls,
rollers, tension devices or other surfaces upon which the travelling film bears
are preferably concaved so that only the edges of the film may come in actual
contact with such surfaces.
The printing device comprises a casing H within which are arranged one or
more electric lights and any well-known form of cinematograph mechanism which
will engage the film A together with a negative film J, and by a step by step
movement present them together at an aperture such as where the light within
the casing H may fall upon them. The cinematograph mechanism within the
printing device is driven by any convenient form of motor, such as an electric
motor. The motor, which is not shown in the drawings, drives on to a
pulley K
mounted fast on a shaft K¹. The shaft K¹ is carried by standards K and is pro-
vided with a worm K³ which engages with a worm wheel K fast on a shaft K³.
The shaft K5 is mounted by any convenient means at right angles to the shaft K',
and is provided with two bevel wheels K K', one at either end of the shaft. The
pulley 03, referred to above as driving the perforator C, is mounted on this shaft K³,
and a second pulley K8 is also mounted on the same. The cinematograph
mechanism is driven by a shaft K" which protrudes into the casing H of the
printing device and is mounted at right angles to the shaft K³ by any convenient
means. The shaft 9 is provided with a bevel wheel K by which it is driven
from the shaft K by means of the bevel wheel K, with which it engages. The
negative film J is wound on a drum J carried by an arm J2, which may be placed
in any convenient position relatively to the printing device. The drum J¹ is
so mounted on the arm J that it may be easily removed therefrom in order that
a fresh negative film may be put in its place when the one in use has been
exhausted. The negative film J, and the unexposed film A are drawn into the
printing device by the cinematograph mechanism, through spring-regulated
tension devices F1 F2 F, the tension of which may be regulated by adjusting the
milled nut with which each is provided. The negative film J is received from
the printing device upon a roller D3, having teeth d for engagement with the
perforations, with which the film is provided at its edges. The roller 13 is pro-
vided with a toothed wheel D', which carries a chain K driven by the wheel K.
The wheel K turns with a shaft K13, carried by standards K. A worm wheel K
(Fig. 1) made fast to the shaft K¹³, engages with and is driven by, a worm K
mounted on the shaft K, referred to above. By this means the toothed roller D
is driven from the shaft K, and a spring-controlled guide-roll E³ serves to keep
the negative film J in proper engagement with the teeth d. A receiving drum Jo,
mounted in any convenient position relatively to the roller 13, is driven from
the pulley K8 on the shaft K by a cord J³, which passes over a pulley Jon the
drum J
The film A, which has now been printed or exposed, is led from the printing
device by guides L to the developing apparatus. The developing apparatus com-
prises four horizontal baths M M M² M³, arranged parallel to each other. The
bath M contains the developing solution, bath M¹ the fixing solution, bath M²
a solution for hardening the gelatine, and the bath M³ glycerine or some similar
material for preventing the film from becoming brittle in drying. At each end
of each bath is mounted a toothed roller M, those at one end of the baths being
carried by a shaft M mounted in bearings M, and those at the opposite end of

page_text: the baths being carried by a shaft M mounted in bearings Ms. The shafts M³ M
are provided with worm wheels M which engage with and are driven by worms M10
carried on a shaft M". The shaft M is mounted in bearings M, and is provided
at one end with a bevel gear wheel M, which engages with the bevel gear
wheel K on the shaft K. By this means the toothed rollers M are all driven
at a uniform speed from the shaft K³, and thus cause the film A to travel in the
manner hereinafter described. Gravity-controlled guide-rolls E are made to bear
upon the film as it passes over the rollers M', mounted on the shaft M, and, if
desired, similar guide-rolls may be provided to operate in conjunction with the
rollers M on the shaft M. The film A is taken from the last roller M of the
shaft over a guide-roll to a revolving storage drum N. The drum N is
driven by means of a pulley N¹ mounted on the revolving shaft M and engaging
with a pulley N on the drum, by means of a cord N. Below the baths M MM² M
is arranged a washing bath or tank 0, through which the film A passes between
leaving one of the baths and entering the next. To avoid any damage owing to
entanglement of the various lengths of film in the tank O, an alarm device is pro-
vided. This device comprises a frame P pivotted in any convenient manner
above the tank 0 at P, and carefully balanced by an arm 12 which carries an
adjustable weight 1. The lower end of the frame P is provided with slots 1",
through which the film A is passed on its way from the tank to any of the
baths arranged above. The frame l' is further provided with a plate p, con-
nected by a wire pl with any convenient source of electric current, and a resilient
member secured to the framing B projects to within a short distance of the
plate on the frame P. This resilient member p² is connected by a wire p
to an electric bell 2, and is so arranged that if brought into contact with the
plate p, the electric circuit is completed and the bell is rung. The water is
supplied to the tank by a supply pipe 01, and is preferably kept in continual
circulation, an overflow 02 being provided.
The operation of the combined apparatus is as follows:-The sensitised film A
is drawn from the drum A', through the tension device. F and under the per-
forator C, by the step by step motion of the pawl e, which engages with the teeth
of the toothed disc D, as described above. The teeth on the dise 12 are so
arranged that at each revolution a sufficient length of film is drawn under the
perforator to carry one cinematograph figure, and the whole of this length is per-
forated by one downward movement of the perforator C before the next movement
of the disc I draws a second length of film beneath it. The perforated film A
on leaving the drum B is carried up to the printing apparatus, and enters the
casing H thereof through the tension device F. The negative film J is at the
same time drawn into the printing device at a point below that at which the
film A enters, so that when engaged by the cinematograph mechanism within the
easing H, the film J is on that side of the film A which is nearest the light men-
tioned above. The cinematograph mechanism engages both films together by
means of the edge perforations in each and by a step by step motion presents at
cach movement a sufficient length of the films to receive one cinematograph
figure at the aperture h. Each length of the films remains opposite the aperture h
where they are fully exposed to the light arranged within the casing H for a
period of time long enough to make the desired impression upon the film A
before the next movement of the mechanism passes it on and exposes a new
length. The step by step cinematograph mechanism is timed to act synchronously
with the step by step perforating mechanism, so that there is no increase or
decrease in the length of film between the two apparatus. As the negative film J
and the film A, which has now been exposed emerge from the casing H of the
printing device, the film Jis engaged by the revolving roller D³
and received by the revolving drum whilst the film A is passed
through the guides L L to the revolving roller M of the bath M which
contains the developing solution. This bath is of such length, and the speed at
which the film A is passed through it is such that on arriving at the opposite

page_text: end of the bath to that at which it enters, the figures are fully developed and it
passes out over the revolving roller M, provided at that end, and down into the
water tank 0. During its passage through the tank the film A is thoroughly
washed, and is then carried through one of the slots P in the frame P of the
alarm device, and is conducted over the roller M at one end of the bath M', which
contains the fixing solution. After passing through this bath the film is again
carried over a roller M, and enters the water tank a second time. It is then
conducted to the bath M and carried through it in the same manner as has already
been described with reference to the baths M and M. The film is then again
washed in the tank and enters the last bath M³, and on its arrival at the end
of this bath, is carried over the guide roll E, and wound on the drum N. When.
a sufficient quantity of film has been wound on the drum N, the drum may be
removed and the film dried in any well-known manner.
The operation of the alarm device is obvious:-
Should any entanglement take place between the different lengths of the film
within the tank the length of film entangled will be prevented from passing
through the slot 1 in the frame 1', and the frame P' being finely balanced will be
carried up by the travelling film until the plate p is brought into contact with
the flexible member 7, when the bell will immediately ring. The alarm
device is so arranged that a very slight movement of the frame P will cause the
bell to ring, so that opportunity may be given to disentangle the film before the
same is in any way damaged.
As the length of the baths and the speed at which the various appliances are
driven are arranged to suit a normally sensitive film, working in conjunction with
a normally clear negative film, means are provided by which the light may be
slightly varied, and the length of time during which the film is immersed in the
different baths regulated. The current to the electric lights within the casing H
in the printing device may be controlled by means of a choking coil indicated at R
(Fig. 1), and a voltmeter may be put in the circuit in order that by adjusting
the choking coil R from time to time the voltage may be kept approximately
constant. If it is desired to shorten the length of time during which the film A.
is immersed in any one of the baths M M M M³, one or more bridge pieces, such
as that shown at S, may be placed across the bath, and the film A carried over it,
and in order that after passing over the bridge piece the film may be readily
immersed, a weighted bridge piece S¹ may be placed over the film at a short
distance from the bridge piece S, so that the film has to pass under it, and is
thus immediately carried to the bottom of the solution. It is also desirable to
leave the film in the washing tank a greater length of time after its immersion
in some of the baths than after its immersion in others. To effect this it is only
necessary when starting the apparatus to retain the free end of the film until a
certain amount of slack has accumulated in the tank, as shown at T, before passing
it on to the next bath.
In case of an accident to any part of the various mechanisms employed, clutches
of any well-known construction may be used, so that any part of the apparatus
concerned may be immediately stopped. Such a device is shown in Figures 1
& mounted on the shaft K by which the cinematograph mechanism may be
immediately stopped. For this purpose the bevel gear wheel K¹ is mounted free
on the shaft K. On one side of it is a collar K mounted fast upon the shaft K".
On the opposite side of the bevel gear wheel K to that on which the collar K17
is mounted, is a sleeve K18, free on the shaft K and beyond the sleeve is a milled
nut K, which is screwed on to a threaded portion K20 of the shaft K. So long
as the nut K is screwed up against the sleeve KS, the latter forces the gear
wheel K against the collar K, and thus causes the gear wheel K to drive the
shaft K, but by screwing the milled nut K away from the sleeve K¹s the gear
wheel K is immediately released, and runs idle upon the shaft K. The shaft K
and the cinematograph mechanism driven thereby can thus be immediately brought
to a standstill whenever desired.

page_text: If preferred the film on leaving the bath M³ may, before being wound on the
drum N, be carried through some suitable drying apparatus, such as that indicated
diagrammatically. at N, (Fig. 2). This apparatus may comprise a chamber heated;
if desired, by any convenient means, through which the film may be passed over a
series of rollers, so that it is retained within the chamber a sufficient length of
time to evaporate the moisture retained by the film. As in drying gelatine film
it is necessary, that each part of the film should be exposed a given amount of
time within the drying apparatus, a toothed roller No may be provided to feed
the film into the apparatus, the roller N being driven by cord and pulleys No N
respectively from the shaft M. The film may then be carried over any con-
venient number of rollers N8 within the drying apparatus, and finally taken from
the last roller N8 by the drum N, already, referred to in connection with Fig. 1.
This apparatus may of course be modified and the film carried over one or more
heated tables, or carried in long lengths from one roller to the other, the lengths
of film lying more or less in a horizontal plane instead of a vertical plane, as
indicated in the diagram in, Fig..2..
One great advantage in this form of developing apparatus is that the whole of
the film during any one operation is exposed to view, which is not the case when
vertical baths are used instead of the horizontal baths described above. To still
further enable the film to be examined whilst under treatment the bottom of
the baths may be formed of some transparent material, as shown at U (Fig. 2).
so that by holding a light beneath the baths every detail of the figures on the film
may be clearly seen. Provision may also be made for observing the films during
the moment of printing. This may be done by providing an aperture 4 in the
casing H, opposite the aperture within the printing device, and to which the
films are presented for exposure. It will of course be understood that as the
sensitive film is continually exposed during its passage from the one apparatus
to another and during the operation of developing, the combined apparatus would
be used in a dark room, and any light used would be filtered through a suitable
mediuni.
A further advantage in this construction of apparatus is that the film is pro-
pelled by toothed rollers, or sprocket feeding wheels, so that there may be no
possibility of slip between the film and the driving mechanism, which has hereto-
fore been found a great inconvenience. It is obvious that if there is slip between
the driven film and the driving mechanism, one part of the mechanism will gain
upon another, thus throwing the general apparatus out of order and the time of
immersion of the film in the baths will vary.
It is obvious that the developing apparatus can be used alone, the exposed
film being fed to the first bath direct from a suitable drum, or may be used in
conjunction with the printing apparatus. only, or, as already described, in con-
junction with both the printing and perforating apparatus.
It will also be understood that the details of this invention may be arranged
to meet various requirements, and the different mechanisms may be variously
arranged in relation to each other without departing from the spirit of this inven-
tion.
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:
1. In apparatus for automatically printing and developing photographic filmís
the combination with a printing device of a series of baths mechanism to propel
the positive film through the baths and means for diverting the negative film
from the baths substantially as described.
2. In apparatus for automatically printing and developing photographic films
the combination with a printing device and a series of baths through which the
exposed film is propelled of an automatic perforating device operating in unison
with the printing device substantially as and for the purpose described.

page_text: 3. In apparatus for automatically printing photographic films the combination
of a cinematograph printing device and a perforating device operatively con-
nected with it.
4. In apparatus for automatically developing photographic films the employ-
ment of a series of shallow horizontal solution baths and mechanism for auto-
matically propelling the film through them whereby the film under treatment is
fully exposed to observation during the whole of its movement through the baths.
5. In apparatus for automatically developing photographic films the employment
of a shallow horizontal solution bath having a transparent bottom for the purpose
described.
ti. In apparatus for automatically developing photographic films a device for
giving an alarm upon entanglement of the film substantially as described.
7. In apparatus for automatically printing and developing photographic films
the combination with a step by step printing device and a series of shallow
horizontal baths of mechanism to propel the film through the series and to operate
the printing device.
8. In apparatus for automatically developing photographic films the com-
bination with a shallow horizontal bath of a bridge piece adjustable along the top
thereof for the purpose described.
9. The combination with apparatus for automatically developing perforated
photographic films of sprocket feeding-wheels for propelling the film for the
purpose described.
10. The combination with apparatus for automatically developing photographie
film of a drying apparatus and sprocket wheels for propelling perforated film
therethrough.
11. In apparatus for automatically developing photographic film the employ-
ment in combination with a drying apparatus of mechanism for propelling the
film therethrough.
12. The complete apparatus for automatic development of photographic films
substantially as described or illustrated in Figures 1, 2 and 3 of the accompanying
drawings.
13. The complete automatic printing and developing apparatus for photographic
films with or without the perforating device substantially as described or illus-
trated in Figures 1, 2 and 3 of the accompanying drawings.
Thated this 14th day of March 1899
BOULT & WADE,
Agents for the Applicants.