Improvements in or relating to the Manufacture of Films for Photographic Purposes.
Year: 1893

page_text: Date of Application, 14th Mar., 1895
Complete Specification Left, 13th Jan., 1894-Accepted, 14th Mar., 1894.
PROVISIONAL DI
Improvements in or relating to the Manufacture of Films for
Photographic Purposes.
communication from THOMAS HENRY BLAIR, of 7, Rue de Colisee, Paris, in
the Republic of France, Gentleman.
I, ALFRED JULICS BOULT, of 323 High Holborn, in the County of Middlesex,
Chartered Patent- Agent, do hereby declare the nature of this invention to be as
follows:-
.
This invention relates to the manufacture of photographic films for use in what
are known as roll-bolders where a long strip of sensitive film is carried in the
apparatus the portions of it to receive the impression being successively brought.
before the lens for exposure.
Hitherto it has been customary to spread the mixture composing the film
upon a glass or equivalent slab after which it is coated with the sensitive
emulsion; this necessitates a great length of slab and consequently of the room
in which it is prepared and has many drawbacks from a commercial point of
view. By the present apparatus I am enabled to dispense with this long table,
and proceed as follows:-
I employ a drum or equivalent revolved by any suitable means. at the required
speed the surface of this drum being smooth and suitably prepared to receive the
mixture or other coating forming the sub-stratum of the film. The drum may be
constructed in any suitable manner and of any suitable materials but I find a
cast iron drum resembling a belt pulley suitably turned up and trued upon the face
to be suitable, and in order to produce the required surface upon its periphery
I may after turning it up coat it with nickel or with copper and nickel or with.
other suitable material, then dress it with a very fine sand blast and finally.
coat it with nickel or other suitable metal or material, for example glass silicate or.
to maintain the
the like. This drum may be cased in partly to protect both drum and the film
upon it to keep out dust, and also as it is then convenient
air within the casing and surrounding the drum at a suitable temperature and
dryness. The upper part of the drum may be exposed or the casing may be
connected with the device supplying the "dope," that is the body of the film
upon which the sensitive emulsion is afterwards to be spread.
The supplying and spreading apparatus may be of any suitable construction say
narrow opening of about the ultimate breadth
0 for example a hopper with a
out or allows it to escape
of the film, the material being allowed to exude through the opening on to
the drum which revolving slowly beneath it draws
as required.
26
The dope is stripped off the drum shortly before it reaches the point a
35 which the fresh. material is supplied and is carried over bands, rollers, or equivalen
supporting devices until sufficiently seasoned to receive the coating of sensitiv
emulsion: the speed of the roller is preferably so adjusted in conjunction with th
condition of the air surrounding the drum that the "dope when removed from
the drum is sufficiently, set or dry.

page_text: To coat the strip of "dope "with the sensitive emulsion it is conducted into a
dark room or chamber through a narrow zigzag channel with a roller at each bend
for the purpose of excluding the light.
The emulsion supplying apparatus may also be of any suitable sort but
preferably I employ a tray or trough supplied with the emulsion and maintained at
the proper temperature, in or over which is a roller conveniently of the same
width as the strip of dope, the roller forcing the strip downwards on to
or into the emulsion bath so that as it passes the strip supplies itself with the
necessary coating of emulsion. After leaving the drum and previous to reaching
this point the strip of "dope" may with advantage he left to hang slack but
it is desirable to have a certain amount of pull or drag upon it from the
zigzag channel until it has fully dried in order to prevent crinkling or bad
surface.
This
From the emulsion coating device the completed film is carried over any suitable
rollers, bands or equivalent supports to the device upon which it is rolled and
carried until the emulsion is set and the complete film is ready for use.
rolling apparatus may be varied in construction, but the following arrangement
has been found to give excellent results. Upon any suitable shaft or spindle is a
small drum or equivalent to which is attached the end of an apron formed of
canvas or other suitable material upon which are preferably placed wooden or
other slats or bars each end of which may be provided with a projecting portion
equal preferably to considerably more than the thickness of the film or other
equivalent means may be adopted to prevent the second layer of film and apron
from touching the former one and to allow sufficient air space. The film is placed
upon the apron or the slats and the winding commences the projections preventing
as will be understood each succeeding layer of film and apron from touching the
preceding one while the film is thus held under suitable tension until dry the pull
of the winding apparatus extending throughout the film back to the emulsion
coating apparatus as previously explained. When one length of apron has been
wound on to the reeling apparatus the film may be cut and another roller and apron
placed in the reeling apparatus, and the recling process proceeded with, or an
entirely fresh reeling apparatus may be brought into play if desired.
While changing from one apron to another or one reeling apparatus to another
the emulsion coating may be stopped although the " lope "drum may continue to
revolve, the slack between the drum and the emulsion coating apparatus already
mentioned allowing of this.
The face of the 68
dope strip which is not in contact with the drum takes a
polished or glazed appearance but the face in contact with the drum, has what may
be termed a "dead" surface or appearance owing to the face of the drum being so
prepared as to produce this; this dead face is the one upon which the sensitive
emulsion is coated and assists it in adhering to the " dope."
Dated this 14th day of March 1893.
W. P. THOMPSON & BOULT,
Agents for the Anglicant
COMPLETE SPECIFICATION.
Improvements in or relating to the Manufacture of Films for
Photographic Purposes.
A communication from TноMAS HENRY BLAIR, of 7, Rue de Colisee, Paris, in
the Republic of France.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention and inf
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 manufacture of photographic films for use in what

page_text: are known to the trade as roll-holders in which a long strip of sensitized film is
carried so that different portions of it for receiving impressions may be brought
successively before the lens of the camera for exposure.
Hitherto it has been customary to spread the mixture, of which the film is
composed, over a slab of glass or other suitable material and then coat it with a
sensitizing solution. This process necessitates a great length of slab and cou-
sequently of the room in which it is located and has many drawbacks from a
commercial point of view.
This invention contemplates the formation of a continuous strip of basic film on
the peripheral surface of a cylinder which under rotation draws out the strip as the
composition or dope is fed on to the surface of the cylinder, and further
contemplates conducting the strip of basic film over suitable supports and through
a suitably-formed light-excluding passage-way, iuto a dark room, where, by means
of suitable guiding supports the strip is passed through or over a sensitive emulsion
from which the strip or basic film receives a coating of sensitized film, the strip
being thence conducted over other supports to an apparatus by which it is rolled up
and properly preserved until in marketable condition.
The invention may be said to reside in an improved method of and apparatus
for making photographic films employing the above provisions in whole or in part.
The accompanying drawings illustrate apparatus embodying the invention.
Figure 1 shows a longitudinal section of means for forming the strip and
conducting it to the dark-room.
Figure 2 shows an elevation of the forming cylinder with its enclosing casing in
section.
Figure 3 shows a side elevation of the means located in the dark-room and
designed to pass the strip through or over the emulsion bath and to roll it up
thereafter.
Figure 4 shows a front end elevation of this part of the apparatus.
Figure 5 shows a plan view of the winding reels.
Figure 6 shows a longitudinal vertical section of the apparatus for applying the
sensitive emulsion coating and of part of the apparatus for rolling up the film.
Figure 7 shows a detail cross-section of the apron in which the film is rolled, and
Figure 8 shows a sectional detail of a track on which the reel-carriages run and
a portion of one of the carriages.
Referring first to Figures 1 and 2, the letter a designates a suitably-constructed
casing on the upper side of which a hopper is supported, and within which is a
drum or cylinder whose peripheral surface is under the discharge opening of the
hopper, and is of a lateral extent equal to or greater than that of said opening.
The discharge opening of the hopper is elongated and narrow so as to emit a stream
of the composition with which the hopper is charged, said composition having the
consistency of thick paste and termed
film. One side of the hopper may be pivotally supported as shown and
dope and forming a foundation or basic
adjustable to vary the width of the discharge-opening and consequently the
thickness of the stream of composition issuing therefrom. The drum or cylinder
may be wholly or partially encased, the object of the casing being to exclude dust
and also to provide for the maintenance of a prescribed temperature and dryness
of the air around the drum. This drum may be constructed in any suitable way,
it being highly desirable. however, that its surface be somewhat roughened or
ground as hereinafter described in order that it may impart a surface to the film
which will enable the latter to hold the sensitive emulsion.
The dope exuding from the hopper encounters the periphery of the drum, and
as the latter slowly revolves, is drawn out thereby into a thin strip 2 extending
over its periphery and adhering thereto.
The drum may be revolved through the agency of any suitable means; it is here
shown as resting upon double-conical dises engaging V-shaped grooves in the
drum and by their frictional engagement therewith adapted fo rotate the drum.

page_text: The said discs are secured on smarts which carry worm-wheels o meshing with
worms on a driving shaft b³.
The strip of dope extends over nearly the entire surface of the drum and is
stripped therefrom in proximity to the supply-hopper. The speed of the drum and
the condition of the air around the same are so regulated that the dope is sufficiently
set and dried when it leaves the drum to be safely handled. The strip of dope
which may now be termed a basic film is taken from the drum between a set of
idle-rollers c, thence over an idler e¹ on the casing a, and is carried over a system
of supports suitably arranged so that the tension on the film may be regulated and
the dope may become "seasoned" in its passage over these supports and fit for the
sensitive emulsion. The arrangement of supports here shown comprises a rack
having tiers of horizontal notched bars, and idlers c whose trunnions engage
notches in said bars. The film enters the rack between a set of idlers in bearings
thereon and is thence conducted in return bends over the idlers which may be
placed variously to support the film as desired and regulate the tension thereof.
The film leaves the rack between a set of idlers & in bearings thereon, and is thence
conducted into a dark-room.
This dark-room is preferably above the film-forming apparatus, and in Figure 1
the letter d designates the floor of said room which has a slot for the film to enter
and to the under side of which is fastened a casing which encloses a zig-zag
passage open at the lower end and registering with the slot in the floor of the
dark-room at the upper end. This zig-zag passage is of a form which effectually
excludes the light and the film 2 is taken up through it into the dark-room, idlers ³
being provided at the bends of the passage-way for the said film to engage.
In the dark-room is erected a stande which supports a trough el designed to
contain a sensitive emulsion which may be maintained at the proper temperature
by any suitable means. As here shown the trough is surrounded on its sides and
bottom by a chamber e, into which steam or water may be conducted, through a
pipe e, an overflow pipe being provided and also a drain pipe c¹ (see Figure 6).
By means of a thermometer ell the temperature may be ascertained. The trough
preferably engages vertical slide-ways on the stand so that it may be moved into
and out of operative position, and the means here shown for adjusting the trough
comprise a rotatable came on which rests roller-provided legs of the trough,
and which carries a ratchet-wheel c' engaged by a pawl. By means of a handle e
fastened to the cam, it may be turned and its acting surfaces caused to raise the
trough or let it down.
The film 2 entering the dark-room is taken up over an idle-roller f in bearings
on the stand e, and thence between a set of idlers comprising a large roller f¹ and
a small roller fe, and therefrom downwardly and under a small roller f³, which
preferably approximates in length the width of the film, and which is designed to
depend in the trough and cause the film to pass through the sensitive emulsion in
said trough and become coated therewith, on one side. The film with the sensitive
coating passes upward from the emulsion and back over the top of the stand, over
a suitable fixed rod or support which may be the rod for the pipe g¹ hereinafter
described.
As there is a positive engagement between the roller fl and the film, this roller
may be employed as a measurer to co-act with a registering device. A strap or
band is here shown as engaging an eccentric on the shaft of the roller f1, and
its rod enters a casing f8 containing a registering mechanism with which said
rod co-acts.
The sensitive emulsion being somewhat warm when applied to the film, it is
found advantageous to subject the film to a cooling and drying agent after leaving
the emulsion and to this end a cold air-pipe is extended through the stand
behind the film and is slotted for the exit of a blast of cold air against the film,
the air being supplied by a suitable blower. A partially cylindrical valve 3 is
arranged within the pipe g and by turning it the slot of the pipe can be opened or

page_text: closed, said valve being turned by means of milled flanges protruding through
the pipe. In the construction here shown the said cold-air pipe is a short distance
above the emulsion and the roller is supported by hangers depending from said
pipe. represents a circulating pipe adapted to conduct cold water in suitable
proximity to the film to exert a cooling action thereon, said pipe being used chiefly
in hot weather when cold air could not have the desired effect.
A suitable pump
may be connected with the pipe to maintain a circulation of water therein.
The rod which supports the film above the pipe gl is supported on said pipe and
serves to support the film above the pipe if desired. The film may pass directly
over the pipe however, in which case the rod f may be omitted.
In order to ensure against crinkling or buckling of the film in its stretch between
the rollers f and f means are employed to constantly exert au influence on the
film tending to straighten it in the direction of its width. The means here shown
consist in endless bands or belts h in contact with the rear side of the film near the
top of the stand, and being constantly driven in a direction to act on the film from
the centre outwardly. At the inner ends these bands pass around horizontal
pulleys supported by a bar of the stand and the stretches of the bands are
carried over vertical pulleys supported by said bar and thence the bands pass
around pulleys affixed on a driving shaft h³.
The film is carried from the sensitizing apparatus to reeling apparatus which
winds the film in rolls and properly preserves it until the sensitive coating
becomes set.
The reeling apparatus here shown is constructed and arranged as follows:-
A pair of wheels and are designed to be rotatively but removably supported
in movable frames or carriages and, and an apron jis attached at its ends to said
reels so as to wind on one while unwinding from the other. This apron is of
canvas or other flexible material, and upon one side thereof are secured transversely-
extending wooden strips j", side by side throughout the length of the apron, said
strips being formed with outward-projecting lugs at the ends which serve to
separate the convolutions of the apron and provide ample space between the same
for the film.
With the apron unwound from one reel the film as it leaves the coating
apparatus is laid in the channel of the apron formed between the end-projections j
and as the reel revolves the film will be rolled up in the convolutions of the apron,
and the said projections prevent contact between each succeeding convolution of
the film and the preceding convolution of the apron. Hence the film can be
preserved thus rolled up until the sensitive coating becomes dry.
When the reel is full the film is severed, and another reeling apparatus may be
substituted.
When the film in the first reeling apparatus is to be removed it may again be
brought into operative relation with the coating apparatus and as the apron is
unwound from the reel janother length of film will be rolled up with the apron on
the reel j.
By reason of the constantly changing relative diameters of the reels, the
driving means applied thereto which are not shown in the accompanying drawings
should be arranged to impel the reels at constantly varying speeds.
The reels may be either both positively rotated or the supplying reel may be
allowed to rotate loosely, the receiving roll being positively driven. Means may
be provided for applying power to either reel leaving the other loose.
The carriages which support the reels are preferably arranged to travel on a
track see Figure 9 the carriages having castors and being confined to the track
by means of lugs received in grooves beside the track and extending under a
flange overhanging the groove.
I prefer to give the periphery of the drum a slightly "toothed " or roughened
surface analogous to that of ground glass in order that a like surface may be
imparted by the drum to the film, while the latter in the form of plastic dope is in
contact with the drum. The surface thus imparted to the film enables the

page_text: sensitive coating to adhere to the film more closely than if the film had a glassy
or perfectly smooth surface. The drum may be roughened or grained by means of
the sand-blast process or otherwise. I find that it is desirable to coat the drum
with some suitable material adapted to be so roughened or grained such as copper
or an alloy of copper and nickel or glass silicate. I do not limit myself however
to the use of the roughened drum and may make the same smooth if preferred.
I am aware of the Specification of Letters Patent. No. 4214 dated
25th February 1893, granted to William Hall Walker and I do not claim
anything described and claimed therein.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondent, and in what manner the
same is to be performed, I declare that what I claim is:-
1. The improved process of making photographic films consisting in feeding the
composition which forms the base or body of the film ou to the surface of a
revolving cylinder which draws it into a thin strip and subsequently coating this
strip with a sensitive emulsion.
2. The improved process of making photographic films consisting in feeding
the composition which forms the base of the film on to the surface of a revolving
cylinder which draws it into a thin strip and conducting said strip through a
sensitive emulsion.
3. The improved process of making photographic films consisting in feeding the
composition which forms the base of the film onto the surface of a revolving cylinder
which draws it into a thin strip carrying the strip over suitably constructed and
arranged guides while it becomes seasoned conducting the strip into a dark-room
and passing it through a sensitive emulsion.
4. The improved process of making photographic films consisting in feeding the
composition which forms the base of the film on to the surface of a revolving.
cylinder which draws it into a thin strip conducting said strip through a sensitive
emulsion carrying the strip over suitably constructed and arranged supports after
leaving the emulsion and subjecting it to a cold air blast.
5. The improved process of making photographic films consisting in drawing out
a stream of dope to form the base of the film, applying a sensitive emulsion thereto
and rolling it up in the convolutions of a carrying device.
6. The improved process of making photographic films consisting in feeding the
composition which forms the base of the film on to the surface of a revolving
cylinder which draws it into a thin strip conducting said strip through a sensitive
emulsion and rolling it up in the convolutions of a carrying device.
7. An apparatus for making photographic films comprising in its construction
means for feeding the composition which forms the base of the film in a plastic
stream and a revolving cylinder which receives the said stream and draws it out over
its surface the periphery of said cylinder being roughened substantially as and for
the purpose described.
8. An apparatus for making photographic films comprising in its construction
means for feeding the composition which forms the base of the film in a stream a
revolving cylinder which receives the said stream and draws it out over its surface
where it becomes a strip and suitably arranged supports over which the strip is
carried from the cylinder in return bends.
9. An apparatus for making photographic films comprising in its construction
means for feeding the composition which forms the base of the film in a stream a
revolving cylinder which receives the said stream and draws it out over its surface
converting it into a strip a dark-room having a zigzag entrance through which the
strip passes and means in said dark-room for applying a coating of sensitive
emulsion to the strip.
10. An apparatus for making photographic films comprising in its construction a
receptacle for sensitive emulsion and means for conducting a continuous strip of
composition forming the base of the film through the emulsion in said receptacle.

page_text: 11. An apparatus for making photographic films comprising in its construction a
receptacle for sensitive emulsion means for conducting a continuous strip of
composition forming the base of the film through the solution in said receptacle and
means for subjecting the coated film to a cold air blast.
12. An apparatus for making photographic films comprising in its construction
means for coating a continuous strip of film with a sensitive emulsion and a reel
carrying an apron in whose convolutions the coated strip may be rolled up.
13. An apparatus for making photographic films comprising in its construction
means for coating a continuous strip of film with a sensitive emulsion a pair of
reels an apron attached at its ends to said reels and adapted to wind on one while
unwinding from the other and to receive the coated strip between its convolutions.
14. In an apparatus for making photographic films, a flexible carrier adapted to
be wound in a roll with the film between its convolutions and provided with side-
projections separating the convolutions and providing a space for the film when
rolled up in the apron.
15. In an apparatus for making photographic films a flexible carrier adapted to
be wound in a roll with the film between its convolutions and provided with
transverse strips having side projections to separate the convolutions às and for the
purpose described.
16. An apparatus for making photographic films comprising means for drawing
out a stream of dope to form the base of the film and for conveying said strip
through a sensitive emulsion and travellers for engaging the sensitized film and
exerting an influence thercou from the middle in an outward direction as and for
the purpose described.
17. An apparatus for making photographic films comprising means for drawing
out a stream of dope to form the base of the film and for conveying said film
through a sensitive emulsion and endless bands engaging the sensitized film and
exerting an influence thereon from the middle outward for the purpose described.
18. An apparatus for making photographic films comprising in its construction a
pair of reels an apron attached to said reels and adapted to wind thereon and
receive the film between its convolutions and means for driving the reels at varying
speed to compensate for the changing diameters caused by the winding and
unwinding of the apron.
19. The combination and arrangement of parts constituting the complete
apparatus for forming the base of a photographic film substantially as described and
Hlustrated in Figures 1 and 2 of the accompanying drawings.
20. The combination and arrangement of parts constituting the complete
apparatus for coating the base of a photographic film with sensitive emulsion
ubstantially as described and illustrated in Figures 3 and 4 of the accompanying
rawings.
21. The combination and arrangement of parts constituting the complete
pparatus for winding up the photographic film substantially as described and
llustrated in Figures 3, 5, and 7 of the accompanying drawings.
22. The combination and arrangement of parts constituting the complete
pparatus for manufacturing photographic films substantially as described and
lustrated in the accompanying drawings.
Dated this 11th love T
W. P. THOMPSON & BOULT,
Agents for the Applicant.