IMPROVEMENTS IN OR RELATING TO HOLDERS FOR PHOTOGRAPHIC FILMS
Year: 1884

page_text: Films.
I ALFRED JULIUS BOULT of 323 High Holborn in the county of Middlesex
Engineer, do hereby declare the nature of the said invention for IMPROVEMENTS
IN OR RELATING TO HOLDERS FOR PHOTOGRAPHIC FILMS (a communication from
George Eastman and William Hall Walker of Rochester, New York, United States
of America, Manufacturers) to be as follows:-
This invention relates to certain improvements in Holders for exposing in the
camera flexible sensitized photographic films.
This improved holder or apparatus for exposing flexible sensitive films in photo-
graphic cameras, consists of an outer casing adapted to be attached light-tight to a
camera of any ordinary construction, and provided with the usual exposing shutter
and enclosing a suitable frame-work secured to the back of the case which frame-
work supports a pair of rollers on which the film is wound a plate which sustains
the film in place during the exposure and the other parts of the apparatus.
This invention also comprises alarm and perforating devices and mechanism for
maintaining a sufficient tension on the film.
There is a roller on which the flexible film is wound before exposure, and which
to distinguish it may be called the "spool."
This invention also comprises the new article of manufacture formed by the
spools wound with flexible photographic films and provided at their ends with
devices by which they may be inserted in a holder the whole being enclosed in a
suitable light-tight case or wrapper ready for delivery to the trade.
The outer casing of this apparatus or device is made of any suitable size and
shape arranged to be attached light-tight to any ordinary camera, and provided
with the usual exposing shutter. The back of the holder is provided with clasps
or other suitable devices by which it is removably secured to the case.
The inside
of the back may be provided with a rabbet by which it is fitted light-tight to the
case. There are two side frames which are connected together at a suitable distance

page_text: apart by cross-bars or rods secured by screws. These frames support the plate and
the spool and the roller on which the film is wound after exposure the latter roller
may for distinction be called the reel. The frame-work and the parts attached
thereto are fastened to the back of the holder by means of catches so that it may
be entirely disconnected from the back or either end may be disconnected at will
so that the frame-work can be turned up at an angle with the hack to afford access
to the spool or the reel. The ends of the frames are made to project so as to
protect the film around the guide-rolls from injury when the frame is turned
upward. The operations of removing exposed films or of inserting fresh spools
wound with film are materially facilitated by this arrangement.
The frames are made preferably of metal; as light as is consistent with sufficient
sirength and of any suitable form adapted to sustain the spool reel plate and guide
rolls in their proper relative positions. At their outside ends the frames are pro-
vided with openings into which the ends of sliding catches engage when the frame
work is connected to the back. The catches are arranged to slide in holes in the
ears of the car-plates being provided with the springs by which their outer ends
are held engaged with the frames and the projecting arms by which they are with-
drawn when required to detach the frame-work from the back.
It is obvious however that any other suitable form of catch or attaching device
may be employed in place of that herein described for detachably connecting the
frame-work to the back of the holder. The device herein described has however
been found satisfactory in practical use.
As already mentioned the sensitive film is introduced into the holder wound (in
sufficient quantity for a number of exposures) on the spool. The film is carried
around the guide roller along the plate or support around a second guide roller and
has its end attached to the reel. An exposure having been made it is required to
move the film along the plate a sufficient distance to bring an unexposed length of
film in front of the plate and this is accomplished by turning the reel by means
of a detachable key or wrench which passes through the casing of the holder in the
proper direction to unwind the film from the spool, and wind up the exposed
portion on the reel.
In order to maintain a sufficient amount of tension on the film and to secure its
lying flat on the plate the reel has a ratchet wheel and spring pawl by which any
reverse motion of the reel is prevented and with the spool a tension device or
spring brake is connected. The tension device also serves to permit any contraction
or expansion of the film due to loss or absorption of moisture. The spool is sup-
ported at one end on the point of a screw so that it may revolve freely The said
screw passes through a threaded hole in the frame and is provided outside the
frame with a milled head by turning which its point may be withdrawn from an
opening in the end of the spool, so that the latter may be removed from the
frame. At the other end the spool is provided with a transverse slot into which
fits a projecting rib on a revolving collar when the reel is placed in the holder.
By this means the collar is caused to turn with the spool. The collar is attached
to a stud to which the inner end of a coiled spring is secured, which revolves with
the stud and spool but offers a certain amount of resistance to the rotation due to
the friction between the outer end of the spring and the inner surface of the circular
recess formed for the reception of the spring in the side-frame. The spring is held
in place in the recess by a cap or cover attached to the frame by screws or other
suitable device The spring-stud is provided with a projecting pin which engages
in an opening in the inner end of the spring. The inner end of the spring stud is
slotted to receive the rib on the collar the end of the stud projecting through the
central opening in the collar and engaging in a hole in the end of the spool serving
to centre the latter on the collar-a pin passing through the spring stud and rib
serves to secure the parts in place-as the spring revolves and as the outer end o
coil of the spring bears against the circular wall of the recess in the frame, the
spring will be compressed when the reel is turned until the strain or pull of the
film on the spool will overcome the friction between the outer end of the spring

page_text: and the recess after which the spring will revolve with the spool whenever the
latter turns, but will constantly maintain an elastic tension on the film, which will
serve to keep the film strained flat along the supporting plate but will permit of
any expansion or contraction in the film cause by losing or absorbing moisture
from the atmosphere. The spring stud may be provided with a threaded hole at
its outer end into which one end of the screw key may be inserted if it is desired
for any purpose to wind back any film onto the spool.
Like the spool the reel is provided at one end with a device by which it may be
removed from the holder it may consist of a screw passing through the frame and
having a milled head on its outer end-at its other end the reel is detachably con-
nected with a toothed wheel so as to revolve therewith in any suitable way.
The toothed wheel or ratched may be supported on the outside of the frame by a
journal which passes through the frame and has the collar secured on its inner end
by a pin. The reel is provided with a projecting stud the end of which is slotted,
and fits an opening in the inner end of the journal the slot engaging with the pin
so as to cause the reel and ratched to revolve together the ratchet is provided with
a threaded bole into which one end of a screw key is fitted when it is desired to
turn the reel to wind the film into it--the direction of the screw being preferably
such that the reel cannot be turned in the wrong direction without unscrewing the
key from the hole.
The construction of a pawl and its spring which are provided is such that the
pawl may be disengaged from the ratchet whenever it is desired to turn the reel
backward to unwind the film or any portion thereof from the reel. The screw key
passes through the casing in an opening in a socket the inner end of which is made
to fit a groove in the side of the ratchet to exclude the light. The socket is
arranged to slide in and out through the case so that its inner end may be dis-
engaged from the groove in the ratchet when the back and frame work of the
holder is removed from the case.
A
In order to attach the end of the film to the reel, the reel is provided with a
swinging clip or bar which extends longitudinally along the reel and holds the
film between its inner surface and the reel. The reel is preferably slightly flattened
lengthways opposite the clip which is provided with arms at each end pivoted on
pins inserted in the ends of the reel; a guide roll revolves on the points of the
screws inserted in the frames It is provided with film perforating and alarm
devices and a longitudinal slot serves to direct a knife in dividing the film.
suitable knife may be provided with the apparatus. The guide roll is preferably
made of wood to secure lightness, in which case it may be provided at each end
with metallic centres to receive the points of the screws which retain it in position.
The diameter of the roll is such that it will make a given number of revolutions
for each length of film requisite for any given exposure which passes around it thus
for an 8 inch exposure the roller if made ths of an inch in diameter will turn
four times. Any other proportion may however be chosen and the guide roll may
be made of such dimensions as to revolve but once for any given length of film.
In order to make the film so as to indicate where it should be divided between
different exposures the guide roll has a projecting point near one or both ends
which point will make a fine perforation near the edge of the film as it passes
around the roll.
1%
In the case supposed, when the roll revolves four times for each length of film
requisite to make a negative of the desired size the film will be perforated four
times for each exposure and consequently requires to be divided at each fourth per-
foration in order to detach the separately exposed portions from each other. The
perforating points are attached to a stein or rod arranged to slide lengthways in
holes made in the roll so that they may be moved outward beyond the edge of the
film as it passes about the roll, in case it be desired for any purpose to throw them
out of action. The end of the said rod may be made to slide outward beyond the
end of the roll as indicated to engage with a hole in the frame to prevent the roll
from turning during the operation of cutting off the film.

page_text: The alarm device may be constructed as follows: The end of the roll is provided
with a projecting stud which at every revolution comes in contact with a spring
attached to the supporting plate or the frame work or casing of the holder,
which spring being bent and released by the movement of the pin recoils and
strikes against the plate or casing so as to make a noise which attracts the attention
of the operator and warns him when to stop turning the reel. In the case supposed,
the spring would strike four blows while the requisite length of film for a single
exposure would pass along the plate.
The guide-roller is simply a plain roller about which the film passes on its way
to the reel.
The film is for convenience wound about a spool in any desired quantity its inner
end heing inserted in a longitudinal groove in the side of the spool and secured in
place therein by a wedge glueing or in any other preferred manner. The spool is
provided at each end with suitable means for supporting it in place in the holder;
as that it may be allowed to revolve therein-which means may consist of a slot and
opening adapted to fit the rib of the collar as hereinbefore described, or any other
suitable devices for accomplishing the purpose. The film is wound on the spool
with its sensitized surface inward as this arrangement will prevent injury to the
film and the holder is constructed to be used with spools wound in this manner.
The spool with the film wound thereon is enclosed in a suitable light-tight case
or wrapper
consist of a round straw-board or paste-board box having a
removable cap or end in which condition the film is delivered to the trade.
which
may
The supporting plate may be made of metal hard-rubber, wood or other suitable
material, being attached to the side frames by means of screws or rivets. If formed
of wood it preferably consists of a series of narrow strips glued together. In order
to prevent any tendency in the film to curl up at the edges thereby throwing it
out of focus along its margins guards are provided on the plate which extend for
a short distance over the edge of the film along its margin and prevent it from
curling outward away from the plate. These guards preferably extend the whole
length of the plate on each side of the film. They may be applied in several
different ways. They may he made in the form of a strip of metal bent into suit-
able shape and attached to the plate by screws or rivets so that the inner edge
projects slightly over the margin of the film. The end of the guard where the film
enters between it and the plate may be bent or heveled outward; to prevent the
margin of the film from injury as it passes this point. The guard may be fastened
to the plate by screws or clips, so that it can be removed therefrom at the time the
film is placed along the plate. Or the guards may be arranged to yield laterally a
short distance to and from the film, being provided with a suitable spring or springs
for this purpose. Or the guard may be attached to the inner side of the case the
guard in this case consisting of a strip of metal or wood attached to the interior of
the casing in such position that when the apparatus is put together for use the
edge of the guard will hold the margin of the film down on the plate in its proper
position.
It is obvious that many changes may be made in this invention without departing
from the principles thereof.
Thus the film straining device may be connected with the reel, a friction brake
being applied to the spool and various other changes may be made in the relative
arrangement of the film operating rollers and the film straining device.
In order to provide for putting the film on the holder without wasting any of it
by winding it onto the reel means may be employed for causing a tension on the
spring at the time the spool is inserted. Thus by slotting the outer end of the stud
and inserting another stud in one end of the key, the key can be used to turn the
stud, thereby coiling up the spring, until a sufficient tension is produced, when the
key is pushed further inward until a stud enters a slot cut in a plate whereby
the spring is held in tension until the spool has been inserted in the holder enough
of the film having been unwound to permit the attachment of its end to the reel
after which the removal of the key allows the spring to uncoil partially and produce

page_text: the requisite strain on the film. Or the same result may be accomplished by
attaching to the stud a ratchet provided with a spring pawl pivoted to the frame
which is engaged with the ratchet until the spool is inserted and the film attached
to the reel after which it is disengaged therefrom so as to allow freedom to the
spring to strain the film.
Another means of accomplishing the same result is as follows:-A notch is cut
in the edge of a collar into which the end of a spring attached to the frame is bent
when it is desired to prevent the principle spring from unwinding. The edge of
the notch is under cut and the end of the other spring is bevelled so that it cannot
release itself from the notch until the collar is partially rotated.
The film tension-device may be combined with the reel using a friction-brake on
the spool but the construction herein shown is preferable.
Dated this 25th day of November 1881

page_text: Improvements in or relating to Holders for Photographic
Films.
I ALFRED JULIUS BOULT of 323 High Holborn, in the county of Middlesex,
Engineer do hereby declare the nature of this invention for "IMPROVEMENTS IN
OR RELATING TO HOLDERS FOR PHOTOGRAPHIC FILMS (a communication from
George Eastman and William Hall Walker, both of Rochester, New York, United
States of America, Manufacturers) and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
The improvements are represented in the accompanying drawings in which
Figure 1 is a side elevation.
Figure 2 represents the interior of the holder one side being removed.
Figure 3 represents the frame and back detached from the case as seen from the
side opposite that shown in Figure 2.
Figure 4 represents a portion of the back, as seen from the inside, showing the
bolts or catches by which the frame is attached thereto.
Figure 5 represents the frame and connected parts as seen from the rear when
detached from the back.
Figure 6 shows the reel or film-receiving roll, the case and frame being shown in
section.
Figure 7 is an end view of the reel, showing the clamp by which the end of the
film is attached thereto.
Figure 8 represents the spool or film-carrying roll,-the tension spring and its
casing being shown in section.
Figure 9 represents a portion of one of the side frames as seen from the inside―
showing the ribbed disc which causes the spool to revolve with the tension spring.
Figure 10 is an end view of the spool, showing the slot on its end which is fitted
to the ribbed dise on the stud of the tension spring.
Figure 11 represents one of the guide-rolls at the ends of the frame, showing
also the film perforating or marking device.
Figure 12 is an end view of one of the guide-rolls, showing also the alarm
device.
Figure 13 is a section through the case showing the spring-clips which hold the
edges of the film in contact with the supporting plate.
Figure 14 represents a portion of the case, as seen from the inside, shewing also
the spring-clips as seen in the direction of the arrow in Figure 13.
Figure 15 represents the spool employed in our improved roll-holder, showing
the film wound thereon and the light-tight enclosing case or wrapper in section.
Figure 16 is a transverse section of the same on the line XX, Figure 15.
Figure 17 is a sectional view through the tension-spring and the barrel which
encloses it.
The improvements consist of a suitable light-tight case or box such as A con-
structed in the manner hereinafter described and adapted to be fitted to any
ordinary camera provided with an exposing shutter B, and enclosing the mechanism
by which the flexible sensitized photographic film is caused to travel along so as to

page_text: provide an unexposed portion for each successive exposure.
The holder may be
made of any desired shape or dimensions according to the size of the negatives
which it is desired to obtain. The case is provided with the usual rabbet a, to
secure a light-tight joint when attached to the body of the camera.
The film which it is found may be used with great advantage is prepared in the
manner for which Provisional protection has been granted upon an application for
Patent No 13596 dated October 14th 1884 and No 7488 June 19th 1885. Other
methods of preparing the film may be employed.
Previous to the exposure the sensitized film is wound on a roll, which, for
convenience is designated as the spool, and as fast as the film is exposed it is
unwound from the spool and wound on to another roll which is called the reel.
The spool F and reel H are supported within the case A by suitable frames (C
which extend parallel to each other within the case and are preferably attached to
the removable back D, which is secure to the case by suitable clasps or hooks G.
The construction is such that the whole mechanism for supporting and shifting the
film may be removed from the case by detaching the back D therefrom: thereby
affording free access to the apparatus for the purpose of removing the exposed film
or of inserting an unexposed spool of film therein. The frames C. C' are attached
together by suitable cross-bars or braces, Figure 5 secured to the frames by the
screws c c or other suitable means.
In the accompanying drawings F represents the spool, H the reel, and I the film,
which extends from the spool to the reel along the film-support E, passing around
the guide-rolls I. I', at each end of the film support.
The detachable key Q Figures 1 and 5, is provided for the purpose of turning
the reel so as to draw the sensitive film along the film-support E, between exposures.
The stem of the detachable key is preferably provided with a thread adapted to fit
the threaded hole X, Figure 6, in the revolving collar O, which is connected to the
reel so that they revolve together, and revolves in a suitable bearing in the side-
frame C. The direction in which the reel and spool turn when the film is being
shifted is represented by the arrows in Figure 1. By providing the stem of the
key Q, with a screw thread it is rendered impossible for the operator to turn
the reel in the wrong direction. In order prevent the entrance of light where
the key passes through the casing A the light-tight-key-connection is inserted
in the casing P, opposite the end of the reel. This key connection is arrange.l to
slide through the casing so that its inner end may be caused to enter an annular
groove in the collar O, for the purpose of excluding the light. The key is inserted
in the collar O through an opening in the key-connection P. When it is desired
to remove the mechanism of this improved roll-holder from the case, the key-
connection is slid outward, so as to withdraw its inner end from the annular groove
in the collar O as indicated by the dotted lines in Figure 6. The mechanisin can
then be removed from the case.
The film-support E consists of a plate of any suitable material attached to the
side-frames CC, so as to sustain the film in the proper position immediately
behind the exposing shutter, the film support may be male of metal, hard rubber,
celluloid, wood or other suitable material. It may also be composed of parallel
strips of wood glued together at their opposing edges as represented in the drawings.
At each end of the film support the guide-rolls 1. Pare arranged to rotate on
the screws or pins finserted in the side frame. The guide-rolls I. I', may be
of metal or wood, in the latter case being provided with the metallic centres h
adapted to receive the points of the screws so as to reduce the friction. The
forward slides of the rolls are placed flush with the surface of film support B.
The frames C. C carrying the film support, spool and reel are preferably made
detachable from the back D. In the drawings the former is represented as attached
to the back by means of the sliding catches J. J.-Figure 4 arranged so that the
frames may be detached from the back at either end and turned up at an angle
thereto as represented by the dotted lines K. K Figure 3. The ends of the side
frames C. (project beyond the outer edges of the guide-rolls 1. I' as indicated at d..

page_text: in the drawings, for the purpose of preventing injury to the film where it passes
around the guide-rolls when the frame is turned upward as indicated in figure 6.
The sliding catches J are attached to the back by means of the brackets g Figure 4,
being provided with a spring by which their outer ends are held in engagement
with the openings formed to receive them in the ends of the side-frames. The
sliding catches are provided with the thumb pieces ii, by which they are drawn
inward when it is desired to detach the frame from the back. Any other suitable
devices may be used for attaching the frame to the back.
Both the reel and the spool are made removable by means of the screws k and l
provided with thumb nuts m and n. The screws and pass through suitable
threaded holes in the side frame C, arranged opposite the centres of the reel and
spool respectively, the inner ends of the screws passing into suitable centrally
located orifices in the reel and spool so that the latter may revolve freely thereon.
The spool F is provided with a longitudinal groove o to which the spool-end of
the film is attached by being inserted therein-being socured in any suitable
way, as for instance, by glue or cement or by being clamped therein by the
introduction of a wedge. The other end of the film is attached to the reel by
means of the swinging clamp bar provided at each end of the reel with the
arms pivoted at 7. Figure 7 so that the clamp-bar may be swung outward on the
reel as indicated by the dotted lines in the last mentioned figure. The side of
the reel is preferably flattened where the clamp-bar comes in contact therewith,
and the end of the film is attached to the reel by being doubled under the clamp-
bar. the strain on the film serving to press the clamp-bar against the reel and
holding the film firmly between the bar and reel. Any other suitable means of
attaching the film to the spool or reel may however be employed.
The end of the reel opposite to the thumb screw k is attached to the collar O so
as to be caused to revolve therewith by means of the stud or pin s, Figures 6 and 7,
provided with a slot »which fits a pin or rib arranged across an opening in
the inner end of the collar which receives the stud. The reel may bowever be
connected with the collar in any other suitable manner, so as to revolve therewith
when the latter is turned by the key which permits of the detachment of the
reel from the collar so as to permit its removal from the apparatus. This arrange-
ment enables the operator to remove the reel when wound with exposed film, from
the holder. The collar O is provided with a milled or knotched edge, with which
the pawl t, Figure 2, engages for the purpose of preventing any reverse motion of
the reel. The pawl t is pivoted to the side frame and provided with a spring u
which is so arranged as to permit the disengagement of the pawl from the notched
edge of the collar. This arrangement allows the reel to be turned backward, in
case the operator desires to wind the exposed film back on to the spool. As the
spring bears against the tail of the pawl it will operate to hold it in position
either when engaged or disengaged from the notched collar. Any other suitable
device may however be employed for preventing the reverse motion of the reel
when the holder is in use and a friction device has been used for this purpose.
A slot w, Figures 10 and 15, is formed in the end of the spool F which receives
the rib z, Figures 8 and 9, projecting outward from the disc R, Figures 8 and 9, 50
that when the spool is turned the disc is caused to revolve therewith. The disc is
attached to a pin or spindle a¹ to which the inner end of the tension-spring el
is fastened as shown in Figures 8 and 17. The outer end of the tension spring e¹
revolves when the spool is turned, against a frictional resistance caused by the
contact of the spring with the inner surface of the barrel S, the spring operating
to maintain an elastic strain or tension on the film extending from the spool to the
reel, and to draw it down flat against the film support E, notwithstanding any
changes in the length of the film from absorption or loss of moisture.
spindle a passes through the disc R,-its end being fitted to a recess c¹ in the end
of the spool. The end of the spindle is slotted to receive the rib z,-a pin being
driven through the spindle and rib to secure the parts together. Provision is thus
made for separating the parts. The outer end of the barrel S consists of a disc V
The

page_text: baving a milled or notched edge which engages with the pawl g' pivoted to the
side-frame. The outer end of the tension spring e bears with friction against
the inner surface of the barrel, which may be either smooth or notched. The
spindle a projects through the barrel, being provided on its outer end with a head
or collar, which holds the barrel in place in the circular recess formed for it in the
side frame. The manner of operating the tension-spring is as follows:-supposing
a spool of film to be inserted in the holder, the pawl is disengaged and the free
end of the film is carried around the roll 11 along the film support E, back around
the roll and attached to the reel by means of the clamp bar, tension is now
applied to the film so as to draw it down tight against the film support, by
throwing the pawl into action turning the disc and barrel from right to left in
Figure 2 or as indicated by the arrow in Figure 1 which compresses the spring el
in consequence of the friction hetween its outer end and the interior of the barrel
and thereby turns the spindle a' and spool F. sufficient to produce the requisite
strain on the film. The pawl g' prevents the barrel from turning When the spool
is caused to revolve in consequence of the shifting of the film along the film
support by the turning of the reel, the outer end of the tension spring e¹ slides
around within the barrel with a constant amount of frictional resistance thereby
maintaining the strain or tension on the film. The spring e operates also to
maintain the tension on the film, notwithstanding the contraction or elongation of
the latter, due to changes in the moisture of the atmosphere. The tension spring
may be made of differing strengths, according to the size or width of the films
which are employed.
It is obvious that many other ways of applying a spring so as to maintain a
tension on the film while being shifted may be adopted without departure from the
principle of this Invention. For instance and by way of illustration, a brake may
be applied to the spool and the spring attached to the reel and such construction
has been used in practice.
In order to prevent any tendency in the films to turn up at their edges, to the
interior of the case are attached the guards T, T, Figures 13 and 14 by which
the film is held in contact with the support at the edges. As represented in the
drawings these guards may consist of straps of suitable material extending along
the support, and attached to the interior of the case, so that their inner margins
project slightly over the edges of the film which is thereby prevented from curling
outward away from the support, so as to be out of focus. The guards may however
be attached to the film support itself or otherwise arranged so as to effect the
desired result.
The
In Figures 15 and 16 is represented a spool full of flexible sensitive photographic
film attached to the removable spool and enclosed in a light-tight case.
drawing shows the manner of preparing the films for the market so that they may
be transported from place to place without suffering injury. The spool F is
provided at each end with suitable means for attaching it to the journals in the
roll-holder, so that it may be supported and allowed to revolve therein, which
means may consist of the slot and recesses in the end of the spool as herein before
described. The inner end of the film L is attached to the spool by being inserted
in a groove and fastened, or attached in any other suitable manner, and the film is
preferably wound on the spool with its sensitized side inward. The spool with the
film wound thereon is enclosed in a suitable light tight case or wrapper A', which
as shewn in the drawings may consist of a round straw-board or paste board box,
having a removable cap or end B' in which condition the film is delivered to the
trade.
The devices by which the proper length of film is measured for each exposure
and by which the proper points are indicated to divide the separate exposures from
each other remain to be described. The proper length of the film for each
exposure is measured by causing a pin h', Figure 12, on the guide roll I or I', to
strike against a spring Z, which when released from the point of the pin, recoils
and strikes against the frame, support or casing, causing a sharp snapping noise or
B

page_text: succession of snaps, which attract the attention of the operator, and warn him that
he has drawn enough film from the spool for the next exposure.
The diameter of
the guide roll I is proportioned to the length of the film to be exposed, thus for
a 10 inch exposure it is convenient to make the guide roll about four-fifths of an
inch in diameter, so that four times its circumference will be ten inches. The
operator will in this case turn the reel H until he hears four snaps caused by the
spring Z when he knows that the desired length of film has been drawn along in
front of the support E. In a similar manner the size of the guide roll may be
proportioned to any desired length of film to be exposed, being made to revolve
any preferred number of times. The pin may be carried by a gear-wheel
meshing with a pinion on the guide-roll, arranged to give the gear but one
revolution for as many turns of the roll as may be required to measure the desired
length of film in which case the operator will stop turning the reel when he hears
the first snap-In the drawings the spring Z is represented as attached to the rear
side of the support E and arranged to strike against the same when released from
the pin .
In order to indicate the places at which those portions of the film which have
been separately exposed should be divided on one of the guide-rolls, the marking
device is employed, which consists of a point projecting from the roll and
With
operating to perforate or mark the film near its edge at each revolution
the size of roll I already mentioned, the film would require to be divided at every
fourth mark.
The operation of this improved roll-holder for photographic films will have been
already understood from the foregoing description. The spool of film having been
inserted in the holder and the roll I being in place, the operator passes the film
over the support E and attaches its end to the reel H by means of the clamp bar P.
The holder is now ready to be used in making exposures in the camera. After
each exposure the operator turns the key Q until the spring Z warns him by the
noise of its recoil that he has drawn a sufficient length of film from the spool.-On
returning to his dark room the exposed parts of the film are separated from the
unused portion.--the end of the latter being again attached to the reel when the
holder is ready for other exposures and so on until the spool of film is entirely
exhausted. The tension device serves to roll the film tightly on the reel, thereby
avoiding abrasion and in rewinding, from the reel on to the spool a sufficient
tension may be secured by pressing the hand against the back of the film on
the reel, or a friction device may be applied to the reel if desired.-it being
understood that the operation of rewinding if necessary is performed in the dark
room.
In Figures 15 and 16 a spool is represented full of flexible sensitive photographic
film attached to the removable spool which it is designed to employ in this
improved roll-holder and enclosed in a light tight case.
The brakes W are also applied to the reel or the spool or both. These brakes
consist preferably of bars of wood or other suitable material arranged lengthwise of
the spool and reel, and caused to press against the film wound thereon by suitable
springs attached to the film support or the side frames. In the drawings the
brake W is shown as supported in place by the springs which are coiled about
the cross-bars but any other suitable means of supporting the same may be
employed.
The object of the brake is to prevent the unwinding of the film from either the
spool or the reel, when the film is cut to separate the exposed from the unexposed
portions and while attaching the free end of the film to the reel.
In order to ensure the division of the film on the proper line the roll I' is
provided with a longitudinal groove, m' which serves to guide the cutting
instrument used in separating the portions of the film which have received the
different exposures, or the exposed from the unexposed film. The marking point
or points are preferably arranged in the groove, at such a position as to perforate
or indent the edge of the film as it passes around the guide-roll.

page_text: Having now particularly described and ascertained the nature of the 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. The complete apparatus for holding and exposing photographic films
constructed and operating substantially in the manner specified and illustrated in
the accompanying drawings.
2. The spool constructed substantially as deseribed.
3. The reel H constructed substantially as described.
42. The combination in an apparatus such as described of the spool F, reel H
film support. E and guide rolls I and 1' with a device acting to maintain the film
in a tense condition during exposure, substantially as described.
5 3. The hercin described roll of flexible sensitive photographic film combined
with a spool provided with means for applying it to a holder and readily
detaching it therefrom the film being attached at one end to the spool and wound
upon it with its sensitive face inwards all substantially as described.
6. 4. In a photographic film holder the combination with a film supply holder and
a feeding mechanism for transferring the film from the holder and into position for
exposure of a tension regulator applied to the film and acting to supplement the
pull of the feeding mechanism substantially as described.
5. In an apparatus such as described an elastic tension regulator such as
described adapted to draw upon and strain the film between its supports and to
continue such action during the feeding of the film and independently of the
feeding devices substantially as described.
S: 6. The combination in a roll holder of the film carrying rolls F and H friction
pieces W and spring substantially as described.
7. In a holder for photographic films the combination with the enclosing case
provided with a shutter as described of a moveable film carrying and feeding
mechanism so connected with its supporting frame or back that said mechanism
and film can be removed from the case substantially as specified.
10. In an apparatus such-us-described a measuring roll I'-in-contact with the
film and provided with an alarm attachment, a film marking device-and-the
longitudinal groove-m' substantially us and for the purpose specified and illustrated
in the accompanying drawings.
18. The hercin described roll of flexible sensitive photographic film enclosed in
a suitable light-tight case or wrapper substantially as and for the purpose
specified.
12. 9. In an apparatus such as described the combination with the film carrying
roll of a friction roll or brake W arranged to act on the reverse or unsensitized
side of the film substantially as and for the purpose specified and illustrated in
Figures 3 and 5 of the accompanying drawings.
13.10. In an apparatus such as described the guards T substantially as and for the
purpose specified and illustrated in Figure 13 of the accompanying drawings.
14. 11. In an apparatus such as described the combination with the casing A and
film carrying roll H of the light tight key connection P substantially as specified
and shown in Figure 6 of the accompanying drawings.
Daind thin 12th dov of August 1885
W. P. THOMPSON & BOULT,
Agents.