Improvements in Apparatus for the Manufacture of Photographic Films
Year: 1889

page_text: Date of Application, 10th Dec., 1889-Accepted, 29th Mar., 1890
66
-COMPLETE SPECIFICATION (AMENDED).
Improvements in Apparatus for the Manufacture of Photographic
Films."
(A communication from GEORGE EASTMAN of Rochester, in the County of Monroe, and
State of New York, United States of America.)
I, ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex,
M.I.M.E., 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 production of flexible photographic film's from a fluid
solution of nitro-cellulose and camphor and in apparatus therefor the said apparatus
being also capable of use in forming thin, uniform coatings or layers of other materials,
and the said invention consists in the novel construction, arrangement and combina-
tion of parts hereinafter fully described and specifically claimed."
In the accompanying drawings there is represented as an example one form of
apparatus used for forming the films according to this invention and in which
Figure 1 is a side elevation, and
Figure 2 a top plan view of the coating mechanism.
Figure 3 is a longitudinal vertical section, and
Figure 4 a transverse vertical section through the bed-plate and frame.
Figure 5 is a front view, Figure 6 a rear view and
Figure 7 a transverse sectional view of the coating devices.
Figure 8 is a view in perspective of a portion of the coating mechanism.
Figure 9 is a view of one of the trailing knife-supports detached.
Figure 10 is a top plan view and Figure 11 is an end view partly in section of the
stripping and winding devices.
Similar letters of reference in the several figures indicate like parts.
The principal elements of the complete machine, apart from the frame work, are a
bed-plate A having a rigid and substantially level, smooth and perhaps polished
surface, a spreading mechanism B adapted and arranged to be moved longitudinally
over the bed-plate and deposit and spread a thin uniform layer of the fluid coating
material; a removable casing C for enclosing the surface of the bed plate, with
exhaust apparatus for drawing off and collecting the volatile solvents, and stripping
and reeling devices capable of being moved over the bed plate, for removing there-
from and winding up the dried film or films.
The bed plate A though preferably constructed of sheets of plate glass may be
constructed of other suitable material having either a polished or dead surface and is
properly supported and levelled, the abutting ends or edges of contiguous sections
being accurately fitted to form close joints. The interstices, if any, are filled in level

page_text: with the surface of the glass by the introduction of a suitable material or composition,
such as cement, plaster-of-Paris, wax, readily fusible metal, etc., with a view to
removing all crevices and depressions into which the fluid solution might enter and
thus produce ridges or other irregularities on the surface and in the thickness of the
film.
The bed plate, when constructed of piate glass can either have a polished or dead
surface and can conveniently be mounted upon its supporting frame in the following
manner :-
The frame A¹ is furnished with a series of cross-bars a provided with means for
independent vertical adjustinent at opposite ends, as by mounting each cross-bar upon
set screws a¹ projecting vertically through brackets a².
The cross-bars that are beneath the joints of the plates composing the bed, are
each furnished with a shallow trough a³ into which is deposited a suitable plastic.or
semi-fluid mixture or compound capable of setting or hardening. The glass is brought
into contact and pressed upon this semi-fluid or plastic body and retained thereon
while the latter is setting or hardening, thus formning a bed whose surface conforms to
that of the glass and affords an equal support. at all points in the width of the plate.
A mixture of plaster-of-Paris and water has been found to answer well for the bed.
as it adheres to the surface of the glass and thus serves not only to support, but also
to prevent the shifting of the bed plate.
The lateral movement of the bed plates is further guarded against by small pieces
preferably of glass cemented to the underside of the glass and abutting against the
inner edges of the main frame.
-
The spreading mechanish B is arranged to travel longitudinally over the bed plate,
and consists of means for depositing the fluid solution upon the surface of the said
bed plate and for spreading and regulating the thickness of the film or coating. In
the present instance it comprises a carriage B¹ mounted so that it may be moved
upon suitable guides or rails b, parallel with the bed plate and attached to the frame.
The driving mechanism shown comprises two chains or belts 62, one on each side
of the bed-plate A mounted upon, and driven in unison by pitch-wheels or pulleys at
the opposite ends of the apparatus.. Each chain is provided with one or more lugs 63
for engaging one or more projecting arms or pins b (Fig 4) on the carriage, so that,
as the chains are set in motion, the carriage will be drawn longitudinally along the
bed plate and its movement will be arrested as soon as the lugs 63 pass around the
pulleys and are withdraw from contact with the projections b*.
Any of the well-known forms of driving mechanism may be employed for starting,
stopping, reversing and adjusting the speed of the chains or belts, the latter being
arranged to move in unison and engage the carriage on opposite sides of the bed plate
in order to ensure an even and regular motion of the spreading devices.
Upon the carriage B₁ and preferably detachably secured thereto, are the depositing
and spreading devices, comprising a hopper B3 having an adjustable discharge
orifice 67 and a spreading blade B with means for adjusting the position of its edge
relatively to the surface of the bed-plate upon which the solution is deposited.
In the example illustrated, the hopper B3 which is secured to the carriage B¹ by
hook and pin connections 65, rests at its opposite ends directly upon the surface of the
bed plate A, so that the blade carried by the hopper will traverse in a plane-substan-
tially parallel with the surface of the bed plate.
Guides separate from the surface of the bed plate may be employed for supporting the
blade, but owing to the fact that it is extremely difficult to arrange and maintain
the guides parallel with the bed plate, particularly when, as in the present instance,
the latter is adjustable, I prefer to mount the hopper directly upon the bed plate, the
ends of the the hopper forming guides to prevent the fluid solution flowing over the
edge of the bed plate. Suitable guides, such as the flanges 6 Figs 4, 5 and 6 are
provided, to prevent lateral motion or displacement of the hopper.
The adjustable discharge opening 6' extends right across the bed-plate A and
through which the solution escapes and is deposited upon the surface beneath as the
carriage is moved over the bed plate.

page_text: One form of adjustable discharge is shown in the drawings, wherein the front wall 68
of the hopper is provided with open bearings to receive a cross rod or pins 6 on the
end walls of the hopper, removable pins 610 serving to retain the front wall upon the
said rod or pins which constitute its pivots. This pivotted front wall s fits snugly
between the end walls, so as to form close joints to prevent the escape of the solution,
and cams 611 secured to a shaft 612 serve to adjust the size of the discharge opening
by swinging the wall 68 on its pivot, to carry its lower end nearer to or allow it to
remove farther from the rear face of the discharge passage. A hand-lever b¹³ and a
suitable gauge or stop is provided for effecting or determining the adjustment..
In the rear of the discharge opening in hopper B³ and mounted upon the latter is
the spreading blade B+.
If it were practicable to readily procure or produce a bed plate whose surface is a
true plane, the blade B might be made in one piece with a straight edge and would
serve for spreading the solution in a thin even coating as the carriage is traversed
over the bed plate, the blade occupying a fixed relation to its supports and the latter
travelling upon the surface of the bed plate; but inasmuch as it is very difficult, if
not impossible to procure sheets of plate glass of the required dimensions and having
perfectly level surfaces, provision is made for adjusting the edge of the blade at
different points in its length so that at all parts it will preserve substantially the same
distance from the surface of the bed plate during the movement of the carriage, that
is to say, the scraping or spreading edge is caused to conform to the profile of the bed
plate in the plane of the edge of the blade.
One mode of producing such a flexible automatically adjusting blade is shown as an
example in the drawings, and consists in forming the blade in sections and supporting
these sections in the same plane in a guide formed between the rear wall of the
hopper and a strip or bar c applied thereto. A separate yielding pressure device is
applied to each blade section, the same consisting in this instance of a bow spring c¹
with its ends engaging the blade section. Each spring c¹ as shown most clearly in
Figure 8 is secured at or near its centre to a holder having a clamp setscrew c
or equivalent means for detachably securing it to a bracket c in rear of the hopper.
The bow form of spring is preferred as by its use both ends of the blade section are
acted upon equally, and any section can be removed or replaced by simply detaching
its spring from the supporting bracket but other means may be employed for securing
the blade sections and their springs in position, and if desired springs other than bow
springs may be used.
Between the sectional blade and the bed plate and preferably beneath the con-
tiguous ends of adjacent sections, are arranged a series of gauges or trailing strips
which operate to maintain the edge of the sectional blade at all times substantially
the same distance from the surface of the bed plate A.
In the preferred construction the gauges are made in the form of wires, rods or
plates pivotally connected to the hopper or to a rod g¹ thereon the gauges being of
such thickness as to support the edge of the sectional blade B at a proper distance
from the surface of the bed plate A to produce a layer or coating of the required
thickness.
The gauges or trailing strips g are located beneath the several joints of the sectional
blade each gauge supporting the proximate ends of adjacent blade sections and their
lower faces are flattened and so bent or shaped as to make close contact with the
surface of the bed plate at a point or points substantially in line with the edge of the
blade.
The under surfaces of the gauges are inclined upwards and narrowed or bevelled
beyond, and in rear of, the blade and the point of contact with the bed plate as shown
clearly in Figure 9.
The removable casing marked C in the drawings may be of any preferred form
construction and material. In the example given it is made in the form of a light
cover suspended from above, and having its side rails so arranged as to rest upon the
surface of the bed-plate along the edges thereof and provided with an inlet opening C

page_text: at one end and an outlet at the opposite end said outlet communicating with a trunk
or conduit C¹ leading to an exhaust apparatus such for example as a fan (2.
The stripping and reeling devices D) are mounted upon a carriage. it may be the
carriage B₁ or one substituted therefor and arranged so that it may be moved
longitudinally over the bed-plate A.
As the sheet formed upon the bed-plate is usually several times the width of
the commercial article it is more convenient to divide it into strips while it is still
lying flat upon the bed-plate to which it adheres and for which purpose there may be
provided cutters or blades which may he attached to the carriage as shown in dotted
lines in Figures 10 and 11. In order to remove the divided strips without disturbing
the films, and to effect a clear separation on the lines of the cuts a series of rolls or
reels D¹ are mounted upon the carriage arranged in different planes and provided
with suitable winding devices or mechanism for actuating them.
The ends of the strips are applied to the rolls D' and the latter are rotated as the
carriage advances whereby the film is stripped from the surface of the bed-plate and
wound evenly upon the rollers.
The adjacent rollers or reels are located in different planes in order that the strips
mounted thereon may be drawn from the bed-plate at different angles, whereby one
strip is separated or stripped from the surface in advance of the adjacent strips the
separation or divergence of contiguous strips as shown in Figure 11 being thus per-
formed on the surface of the bed-plate and the tearing of the material is thereby
prevented.
By the use of travelling rollers or reels for winding the strips and effecting the
separation of the latter an equal tension is put on each strip and distortion or rupture
of the film thereby prevented.
The reels or rolls D¹ are mounted upon or connected to two shafts d geared together
to rotate in unison so that all the rolls are given the same motion and to provide for
slight variations in tension the several rolls may be connected to their shafts or driving
inechanism through suitable yielding tension devices such as springs &.
The operation of the machine as a whole is as follows;-
After the gauges g, interposed between the sectional blade B and the surface of
the bed plate A, have been adjusted or regulated so as to support the edge of the blade
at the proper distance from the surface of the bed-plate A to produce a layer or coating
of the desired depth and the discharge opening in the hopper B3 has been adjusted
proportionally to the rate of motion to be given the carriage and to the degree of
fluidity of the solution or other material to be spread the coating material consisting
of nitro-cellulose and camphor dissolved in a volatile fluid solvent such as methyl
alcohol so as to form a clear fluid solution, is poured into the hopper B³ or delivered
therein through a regulated discharge and the driving mechanism is then set in
motion.
The fluid escaping from the hopper B³ is deposited in a measured stream upon the
surface of the bed plate in advance of the spreading blade B and is prevented from
running over the edges of the bed-plate by the guides or ends 60 of the hopper, which
rest upon the surface of the bed-plate. As the carriage advances the solution is spread
or distributed upon the surface of the berl-plate in the form of a thin layer of substan-
tially unifrom depth by the action of the blade B*.
It might be presumed that the slight irregularities existing in the surface of the
ordinary plate glass would not produce any appreciable or material variation in the
dimensions of the coating, but such is not the case, as will be readily understood when
it is considered for what purposes the films are designed, and that as ordinarily made,
they are but from 3 to 5 one-thousandths of an inch in thickness, although the
coating, as at first applied, is somewhat thicker, allowance being made in such coat-
ing for the volatile solvents contained in the solution and which are afterwards
removed.
It is to counteract the defective action resulting from the irregularities in the plane
of the surface that the blade B is made flexible, and the gauges g arranged at
different points in the length of the blade and interposed between the latter and the

page_text: surface so that the edge of the different parts of the blade will be autoinatically shifted
and be held at all times substantially parallel with the surface of the bed-plate, but
removed therefrom, thus forming a passage of uniform dimension through which the
solution is drawn or escapes as the hopper advances over the bed-plate.
The solution employed, when spread out in a thin sheet, sets rapidly, a thin skin
being formed on the surface which prevents the material from flowing readily and it
is because the gauges occupy more or less of the surface of the bed plate A in the
opening beneath the blade that their rear under surfaces are inclined and bevelled in
the manner shown in Figure 9 so as to enable the still material to run together and
form a continuous sheet before setting, or if it is desired to cover but a portion of the
surface of the bed-plate or produce two or more separate sheets or strips, the gauges
corresponding in position to the edge or line of separation may be flattened and
prolonged somewhat in rear of the blade.
When the solution has all been spread or the carriage is arrested, as by the
disengagement of the lugs on the chains b from the arms or pins 6 Fig 4 the
casing C is drawn over or placed in position to cover the bed plate A and the exhaust
apparatus is set in motion.
The covering of the layer of solution with the casing C is for a two-fold purpose, to
exclude dust etc., from the surface of the material and to prevent the volatile solvents
from escaping into the atmosphere, as they are highly injurious, besides which they
are valuable products and can be recovered but the drying of the solution may be
effected by direct exposure to the atmosphere which if desired may be artificially
heated.
The
The exhaust fan C² or other apparatus provided for the purpose draws atmospheric
air through the opening Cx in the end of the casing which opening is covered with
some material such as inuslin so as to arrest any dust there may be in the air.
solvents escaping from the coating on the bed plate and withdrawn by the blast C
can afterwards be recovered by any of the well known methods such for example as
bringing them in contact with a spray of water, from which water they can subse-
quently be separated.
In drying, the layer of nitro-cellulose and camphor hereinafter termed the supporting
film becomes diminished in thickness, by the removal of its solvents, and when dry,
will be found to adhere closely to the surface of the bed-plate, so much so that considerable
force is required to detach it therefrom.
The next proceeding, if sensitized photographic films are to be produced, is to apply
a thin even coating of sensitized emulsion such as gelatino argentic emulsion and
then cover and dry the same, after which the film is ready to be removed.
The spreading of the emulsion may be performed by the same apparatus as is used
for spreading the film of nitro-cellulose and camphor or by any other suitable coating
device.
The removal of the complete film from the surface of the bed-plate is accomplished
by attaching one end to a reel or roller extending right across the bed plate; but if the
filin, as produced by the machine, is wider than is required for use, and it is desired
to divide it into two or more strips, this can be accomplished while the material lies
flat upon and adheres to the surface upon which it was formed by running the before
mentioned cutting edges or knives along the surface, for which purpose the knives
may preferably be attached to the carriage as indicated in Figures 10 and 11 by
dotted lines.
The ends of the several strips of filin are then detached from the surface of the
bed-plate and each connected to one of the reels D¹ on the movable carriage.
The reels being located in different planes draw the strips from the surface at
different angles, and the tension being regulated, one series of strips will be drawn
from the surface in advance of the other.
Each strip is thus placed under equal tension throughout its width, and as the roll is
simultaneously advanced and rotated, the film is stripped from the surface without
danger of being distorted, torn, or otherwise damaged.

page_text: Having now particularly described and ascertained the nature of this said
invention 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 :-
1. In a machine, such as described, the combination of a bed-plate having a
substantially flat surface and a travelling coating apparatus mounted and
reciprocating upon guides parallel with the surface of the bed-plate; substantially as
described.
2. In a machine, such as described, the combination with a depositing and spreading
apparatus mounted upon guides, of a sectional bed-plate composed of sheets of glass
with the interstices between the abutting edges filled with plaster-of-Paris or equivalent
material level with the surface of the sheets, to form a bed-plate having a continuous
surface; substantially as described.
3. In a machine, such as described, the combination to form the bed-plate for
the reception of the film, of the frame, the vertically adjustable cross bars, sheets
of glass resting upon said beds, and a filling of plastic material between the edges
of adjacent sheets to form a continuation of the surface thereof, substantially as
described.
4. In a machine, such as described, the combination with the bed-plate of
a travelling coating device provided with a receptacle for the fluid, having a dis-
charge orifice and a spreading blade supported in rear of said discharge orifice and
extending transversely across, and parallel with, the surface of the bed-plate, sub-
stantially as described.
5. In a machine, such as described, the combination of the bed-plate, a travelling
hopper or receptacle for the fluid, having a discharge orifice and spreader, and
guides travelling with the hopper and engaging the surface of the bed-plate to
prevent the fluid from spreading laterally, substantially as described.
6. In a machine, such as described, the combination with the bed-plate, of the
travelling hopper supported on guides engaging the surface of the bed-plate, said
hopper having a discharge orifice and a spreader in rear thereof, substantially as
described.
7. In a machine, such as described, the combination with the bed-plate, and
travelling carriage supported upon guides parallel with the bed-plate, of a depositing
and spreading device mounted and guided upon the surface of the bed-plate and
connected to the carriage, substantially as described.
8. In a machine, such as described, the combination with the bed-plate, the
carriage supported upon guides and traversing longitudinally of the bed-plate and
mechanism for actuating said carriage, of a coating device connected to said carriage,
mounted directly upon the surface of the bed-plate; and provided with a receptacle
for the reception and discliarge of the fluid upon the bed-plate and a spreader blade,
substantially as described.
9. In a machine, such as described, the combination with the stationary bed-plate
and movable carriage, of the hopper detachably secured to said carriage and provided
with guides engaging the face of the bed-plate, said hopper being provided with
a regulated discharge and a spreading blade, substantially as described.
10. In a machine, such as described, the combination with the surface upon which
the film is formed, and a receptacle for containing and discharging the solution
upon said surface, of a flexible spreading blade, and a series of gauges interposed
between said blade and the surface designed to receive the solution, for automatically
adjusting the edge of said blade, substantially as described.
11: In a machine, such as described, wherein the fluid is deposited and spread
upon a retaining surface, and in combination with the devices for depositing such
fluid, and the surface upon which it is deposited, an automatically adjusting spreading
blade, the same consisting of a series of independent sections supported upon gauges
interposed between the blade sections and the surface upon which the solution is
deposited, substantially as described.
12. In combination with the sectional spreader blade, and independent pressure

page_text: devices applied to the sections thereof, the gauges interposed between the ends of the
adjacent blade sections and the surface upon which the film is formed or spread by
the blade, substantially as described.
13. In a machine, such as described, and in combination with the bed-plate and a
hopper movable longitudinally of, and parallel with, the surface of the bed-plate and
provided with a discharge orifice for the fluid, a sectional spreader blade supported in
rear of the hopper each blade section being provided with an independent pressure
device and gauges engaging the surface of the bed-plate, substantially as described.
14. In a machine, such as described, and in combination with the sectional spreader-
blade supported in rear of the hopper, a pressure spring applied to each blade-section
to force it towards the bed-plate, and two gauges interposed between each blade-
section and the hed-plate, to adjust and sustain said blade-sections with their edges
removed from, and substantially parallel with, the surface of the bed-plate, substantially
as described
15. In a machine, such as described, the combination with the bed-plate
and sectional blade co-operating therewith to form a film or layer of the fluid, a series
of gauges or supports for the blade-sections resting in contact with the surface of the
bed-plate and provided with converging or bevelled sides, substantially as
described.
16. In a machine, such as described, and in combination with the sectional
spreader blade, a series of trailing strips pivotally supported at one end and extending
beneath the blade sections and resting in contact with the surface of the bed-plate or
supporting surface for the film, substantially as described.
17. In a machine, such as described, the combination with the sectional spreader-
blade and supports engaging the bed-plate to hold said blade-sections removed
from the latter, the bow springs engaging said blade-sections to press them towards
the bed-plate, substantially as described.
18. In a machine, such as described, and in combination with a blade-section, a
bow spring attached to a bracket at or near its centre, with its ends engaging the
blade section, substantially as described.
19. In a machine, such as described, the combination with the rear and end walls
of the hopper, of the pivotted front wall and adjusting devices, such as cams, operating
to adjust the discharge orifice, substantially as described.
20. In a machine, such as described, the combination of the bed-plate, the carriage
travelling on guides parallel with the bed-plate, the chains or belts on opposite sides
of the bed-plate driven in unison and provided with devices engaging the carriage,
substantially as described.
21. In a machine, such as described, the combination of the bed-plate, the
travelling carriage, the hopper attached to the carriage and provided with a regulated
discharge orifice, and the sectional spreader blade mounted in rear of the hopper and
provided with pressure devices and gauges for sustaining the edge of the blade
substantially parallel with the surface of the bed-plate, as set forth.
2. In-n mmchine; such-us-described, the combination--with the-bed-plate-upon
the-surface-of-which-the-film-is-formed, of a removable-easing-for-covering-the-film
while-drying, and-an-exhaust-apparatus-in-communication-with-the-interior-of-snid
ensing-substantially-as-described.
23. In-n-machine-sueh-as-described;-the-combination-with-the-frame,-bed-plate
and-the-trunk-or--conduit-communicating-with-an-exhaust-apparatus-or-device;-of
an-outlet-at-the-other-end--opening-into-the-exhaust-conduit;--substantially--as
the removable-easing provided-with-an-inlet-orifice-at-one-end-of-the-bed-plate-and
deseribed.
21. In-a-machine, such-ns-deseribed, and-in-combination with-the-bed-or-plate
upon-which-the film is formed-and-to-which-it-adheres; a carriage traversing said
bed and provided-with-one-or-more-cutters--for--dividing-the-film-into-strips
while-attached-to-the-bed, substantially-as-described:
25. In a machine, such as described;-the-combination-with--the--supporting

page_text: surface--to--which--the film adheres, of a-traversing winding reel; substantially
as described:
26. In-n-machine-such-as-described, the combination of a supporting surface on
which the film-is-formed;-a-earringe-mounted-on-guides-and-traversing longitudinally
of said--supporting surface, and two-or--more--winding-reels-mounted-upon said
earringe-in-different planes, substantially as described.
27. In-a-machine, such as-described; the combination with the supporting surface
or-bed-plate-upon--which-the-film-is--formed, a--travelling earringe, and--rollers
mounted-upon--said-carriage--in-different planes, to support the-strips-and-draw
adjacent-strips-at different angles from the surface; substantially as described.
22. In a machine, such-ns described; the combination--of the--bed-plate---the
traversing-earringe, and two series of winding rollers or reels-mounted-upon separate
shafts-on-said-earringe-substantially-as-described.
20. In-a-machine, such-as-described,-the-combination of the-hed plate, the travers-
ing earringe and two-shafts-mounted-upon-said-earringe and geared to gether,-each
of said shafts-being provided with a winding roll-or-reel, substantially-as-deseribed.
30. In-n--machine, such--a
--as-described; the combination with the bed plate or
surface--upon-which-the-film--is formed-and-separated into strips-while adhering
therete, of a travelling curringe, winding rolls or reels, and driving mechanism
therefor, mounted upon said-carringe, and-yielding tension devices such as springs,
intermediate-the-reels-and-their-driving mechanism, substantially-us-described.
22. 34. The general combination and arrangement of parts constituting the com-
plete film spreading device substantially as herein described and illustrated in the
accompanying drawings.
32. The general-combination-and-arrangement of parts constituting the complete
film-detaching and winding device-substantially us herein-described-and-illustrated
in Figs 10-and-11-of the accompanying drawings.
23. 33. The general combination and arrangement of parts constituting the com-
plete machine substantially as herein described and illustrated in the accompanying
drawings.
"