Improvements in Film Changing Photographic Cameras.
Year: 1894

page_text: Date of Application, 14th Apr., 1894
Complete Specification Left, 14th Jan., 1895-Accepted, 9th Mar., 1895
PROVISIONAL SPECIFICATION.
Improvements in Film Changing Photographic Cameras.
I, JOSEPH THACHER CLARKE, of 3 College Terrace, Harrow, Middlesex,
Architect, do hereby declare the nature of this invention to be as follows:-
My invention relates to photographic cameras of that type in which a pack or
series of flexible sensitized films, without sheaths or holders, are separated and
released, seriatim, by means of suitable selecting devices, and are thereupon caused
Film changing
to drop by their own weight so as to form another pack or series.
cameras of this type, working upon what may be termed the gravity system, were
first described by me in Letters Patent No. 11991 of 1890, and are now widely
known in practice.
Hitherto the released and deposited sheets,--that is to say those films which
have been exposed and changed, have been retained in the secondary pack or
series, and prevented from falling into the body of the camera on this being
inverted, by means of two devices: the first of these (described in the before-
mentioned Letters Patent No. 11891. of 1890) being a presser foot which was
raised when a sheet was to be deposited, and was afterwards returned to bear upon
and retain the series of deposited sheets; the second (described in Letters Patent
No. 9819 of 1892) being a flexible dividing band or septum which intervened
between the holder of the primary or unexposed series of films and the pack of
released and deposited films, the said septum being carried out of the way of the
dropping film through the rotation of the holder, to which one end of it was
attached.
The purpose of my present invention is to provide a third and novel means of
retaining the pack of released and deposited films. This I effect by constructing
upon the top or the bottom of the camera case, or upon one of the sides thereof, a
chamber for the reception of the discharged films, but little larger in plan than the
films which are to be stored therein, so that these filtns can shift but little in a
lateral direction, the said chamber being provided, along that inner side through
which the films are introduced, with narrow border strips or ledges, projecting so
far from two or more sides of the receiving chamber that a film when once forced
and bent past these ledges cannot again fall through them into the body of the
camera, even though this be inverted. These ledges, which are situated, as will be
readily understood, in a plane parallel to the face of the pack of exposed films
stored in the receiving chamber, have between them an aperture slightly smaller
than the corresponding dimension of the sheets which are to be pushed through
between them, and are thenceforth to be retained by them. The thickness of these
ledges is immaterial, provided they be of sufficient rigidity to withstand the thrust
of the film which is pushed past them, and to support the pack of deposited films
retained behind them. They may be formed as projections perpendicular to the
walls of the camera case and parallel to the films in the receiving chamber, or
they may be somewhat inclined towards the interior of the chamber, so as to
facilitate the bending of the films which are passed between them.
It is plain that a flexible sheet or film, when dropped upon these ledges, inust, in
order to pass between them, be slightly bent, and the force requisite herefor I
preferably apply by means of a stamping-through device, or pusher, which is moved
aside when a film is to be discharged from the primary series, and is thereafter

page_text: advanced between and sufficiently past the aforesaid ledges to carry before it the
discharged film, which is thus so flexed as to pass the gate formed by the ledges.
I do not limit myself to a particular conformation of said pusher, which may be of
any shape so long as it is adapted to perform its function in combination with the
ledges, but a convenient method is to construct the pusher as a thin board or flap,
so hinged or linked to the walls of the camera as to be movable towards and away
from the ledged entrance to the receiving chamber. This flap forms, when with-
drawn, a slanting division within the body of the camera, the interior of which
thus resembles a hopper into which the released filin drops when the lens end of
the camera is pointed downwards, and the selecting and separating devices are
operated. The flap advances, when closed, just beyond the aforesaid ledges, between
which the film is thus caused to pass and to enter the receiving chamber. Such a
pushing device may be operated from the outside of the camera in any convenient
manner, as for instance by the direct action of a rod passing through a light-tight
fitting in the walls of the case. The operating mechanism may be connected with
the selecting and separating film changing devices, so that one and the same move-
ment from the outside of the camera shall first withdraw the pusher and thereupon
separate. and drop the foremost film. The motion of that end of the pusher which
is nearest to the unexposed films may, by means of a link or double hinge, be made
exactly parallel to the front of the primary pack, and this end may be provided
with a brush or pad of any suitable material, such as plush, which shall sweep
along and dust off the foremost sensitive surface in such wise as to remove there-
from any loose particles which might otherwise prove detrimental to the resulting
negative.
When it is desired to compress the pack of deposited films in the receiving
chamber, this space may be fitted with a light pressure board, bearing with its
spiral spring outwards upon the wall of the camera case, and with its board inwards
against the ledges before described, or against the films which have been introduced
into the chamber. Such a pressure board will, in the operation of film changing,
be compressed and moved backwards by the thrust of the pusher, until the deposited
film has been carried past the ledges. On the pusher being withdrawn the pressure
board will return to hold the secondary pack of exposed films into contact with the
ledges.
Access to the receiving chamber, through the wall of the camera case, may be
provided by any of the light-tight slides or hinged doors which are in common
usage, or the receiving chamber, together with its ledges, may be constructed as a
separate tray, which can be withdrawn through that aperture which gives access to
the primary series of unexposed films.
Dated this 14th day of April 1894.
Improvements in Film Changing Photographic Cameras.
I, JOSEPH THACHER CLARKE, of Boston, Massachusetts, United States of
America, but at present residing at 3 College Terrace, Harrow, in the County of
Middlesex, Architect, 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 photographic cameras of that type in which a pack or
series of flexible sensitized films, unprovided with sheaths or carriers, are separated
and released, seriatim, by means of suitable devices, and are thereupon caused to
drop from the holder in which they were exposed, so as to form another pack or
series. Film changing cameras of this type, working upon what may be called the

page_text: gravity system, were first described by me in Letters Patent No. 11891 of 1890,
and are now, in several varieties, known to those skilled in the photographic art.
Hitherto the released and deposited sheets,-that is to say those films which
have been exposed and changed,-have been retained in the secondary pack or
series, and prevented from falling into the body of the camera, ou this being
inverted, by means of two devices: the first of these (described in the before-
mentioned Letters Patent No. 11891 of 1890) being a presser foot which was
raised when a sheet was to be deposited, and was afterwards returned to bear
upon and retain the series of deposited sheets; the second (described in Letters
Patent No. 9819 of 1892) being a flexible dividing band or septum which intervened
between the holder of the primary series of unexposed films and the secondary pack
of released and deposited films, the said septum being carried out of the way
of the dropping film through the rotation of the holder, to which one end of it was
attached.
The purpose of the present invention is to provide a novel and improved method
of retaining the secondary pack of released and deposited films. This end is
effected by constructing upon the top, bottom, or back of the camera case, or upon
one of the sides thereof, a chamber for the reception of the discharged films, the
said chamber being but little larger in plan than the length and width of the films
which are to be stored therein, so that these films can shift but little in a lateral
direction, and being provided, along that side towards the interior of the camera
through which the changed films are introduced, with narrow border strips or ledges,
projecting so far from two or more sides of the receiving chamber that a film which
has been forced and bent past these ledges cannot by its own weight fall past and
between them into the body of the camera, even when this is inverted. These
ledges, which are situated, as will be readily understood, in a plane parallel to the
face of the pack of exposed films stored in the receiving chamber, have between
them an aperture slightly smaller than the corresponding dimension of the sheets
which are to be forced through between them, and are thenceforth to be retained
by them. The thickness of these ledges is immaterial, provided they be of
sufficient rigidity to withstand the thrust of the film which is pushed past them, and
to support the pack of deposited films retained behind them. They may be formed
as projections perpendicular to the walls of the camera case and parallel to the
films in the receiving, chamber, or they may be somewhat inclined towards the
interior of this chamber, so as to facilitate the bending of the films which are
passed between them.
When a flexible sheet or film is dropped upon these ledges from the holder in
which the exposure was made, it must, in order to pass between them, be slightly
bent, and the force requisite herefor I preferably apply by means of a stamping-
through device or pusher, which is moved aside when a film is to be discharged
from the primary series, and is thereafter advanced between and a little past the
aforesaid ledges,' so as push before it the discharged film which is thereby so bent
and curved as to pass through the aperture remaining between the ledges. I do
not, however, limit myself to any particular formation of such a pusher, which may
be of any shape adapted to perform its function of pushing the discharged film past
It will be obvious that
the ledges, so that it will thereafter be retained by them.
the gist of the present invention lies in the ledges themselves, and the bending of
flexible films past them.
Having thus outlined the arrangement and performance of the apparatus, I will,
in order that my invention may be clearly understood, describe in detail a simple
and effectual method of constructing a ledged receiving chamber in a film changing
photographic camera, reference being had to the appended drawings, where
identical parts are designated by the same reference numbers.
Figure 1 is a vertical longitudinal section through the center of a camera provided
with a ledged chamber, in accordance with the present invention. The mechanism
for introducing the films into the storage chamber and for retaining them thereni
is here shown complete, while the view finders, the lens, its exposure shutter, etc.,

page_text: as well as the devices for selecting and releasing the foremost film, not being
included within the scope of the present invention, are either omitted altogether,
or are indicated only in such part as need be referred to in connection herewith.
Figure 2 is a vertical transverse section, on the broken line Z-Z, Fig. 1, of
the same apparatus.
The broken line Y-Y, Fig. 2, indicates the section taken in Fig. 1.
The stamping-through device or pusher, 1, is shown in Fig. 1 as withdrawn for
the purpose of permitting the release and effecting the change of the film last
exposed, 2, which has fallen upon it and is about to be deposited in the receiving
chamber by being pushed past the ledges, 3, so as to be added to the secondary
pack of exposed films, 4, in the receiving chamber, 5.
In Fig. 2. the pusher, 1,'is shown in the position which it occupies when not in
operation. In assuming this position the pusher, 1, is passed between and beyond
the ledges, 3, so that it bears upon the face of the pack of exposed and deposited
films, 4, within the receiving chamber, 5. Otherwise this pack of deposited films, 4,
will rest with its edges upon the ledges, 3, in the manner shown in Fig. 1.
The unexposed films, 6, are introduced into the holder, 7, in which they are
exposed, through the hinged door, 8. They are brought up to the register of focus
through the pressure of a backboard, 9, provided with a coiled spring, 10.
In the appended drawings the method of selecting and separating the foremost
sheet of this primary pack is shown, exempli gratia, as that now familiar in practice
as the "Frena system." In accordance with this system, notches, 11, of two
patterns, are cut in the edges of the films; the films thus notched are packed in
alternate sequence; and the sides of the holder, 7, are provided with sliding
pointers, 12, which are adapted, when moved to the corresponding positions, to
pass through the notches in the foremost film, and thereby to effect the release of
this film from the holder. The preferred method of notching and arranging such
films has been particularly set forth in Letters Patent No. 23315 of 1892. I wish
it, however, to be understood that the method of releasing the foremost film forms
no part of the present invention, which is applicable to any form of film changing
camera dropping separate flexible sheets from the holder in which they have been
exposed.
In the simple form of stamping-through device illustrated in the appended
drawings, a metal plate, 1, is operated from the outside of the camera by the direct
push of a double rod, 13. This double rod, 13, is connected with the stamper, 1, by
means of pivots, 14, which project through slots, 15, pierced in each side of the
camera case. The stamper, 1, turning freely upon the pivots, 14, is further
provided with guide pins, 16, which travel in slots, 17, pierced in the sides of the
camera case. The travel of the stamper, 1, when operated by means of the
connected rod, 13, is limited by these pivots and guide pins in such wise that, when
entirely withdrawn for the purpose of film changing, it will assume the position
shown in Fig. 1, forming a slanting division within the body of the camera, the
interior of which thus resembles a hopper, 18, into which the released film, 2,
drops when the lens end, 19, of the camera is pointed downwards and the film
selecting and separating devices (of whatever nature) are operated. When the
film, 2, has been thus dropped, the stamper, 1, is returned by pushing in the rods, 13,
when it will assume the position shown in Fig. 2. By this return movement the
stamper, 1, will carry forward the changing film, 2, against the ledges, 3, and by
bending or curving the corresponding edges of the film will force it between and
past the said ledges, so that the film last deposited will occupy the position in the
receiving chamber, 5, indicated by the reference number 20, Fig. 2.
The travel of that end of the stamping-through device which is nearest to the
face of the unexposed films may, by means of a double hinge or link, or by a
somewhat different arrangement of pins and guide slots, be made exactly paralle!
to the front of the primary pack in the holder, and this end may then be provided
with a brush or pad of any suitable soft material, such as plush, which shall sweep
along and dust off the foremost sensitive surface in such wise as to remove

page_text: therefrom any loose particles which might otherwise prove detrimental to the
resulting negative.
Access to the receiving chamber, 5, is provided by the hinged door, 21, through
which the changed films are removed for development. Or, should it be preferred,
the receiving chamber may be constructed as a separate sliding tray which can be
withdrawn through that aperture which gives access to the primary series of
unexposed films in the holder.
When it is desired to retain the pack of exposed and deposited films, 4, under
constant pressure, a secondary pressure board, 22, provided with a coiled spring 23,.
is placed within the receiving chamber, 5, as shown in the appended drawings..
The action of this secondary pressure board, 22, when the stamper, 1, is withdrawn
for the purpose of film changing, will be to carry the pack of deposited films, 4,
against the ledges, 3, by which the edges of the pack will be supported and retained.
Let it be understood, however, that the introduction of such a secondary pressure
board is not absolutely essential for the purposes of the present invention: the
ledges, 3, will retain, without the aid of such a pressure board, any fairly stiff and
flat films passed between them, provided that the receiving chamber be not so deep
as to make its diagonal exceed its width (or, in other words, the width of the
films to be deposited therein) by more than the projecting width of one of the
ledges, 3.
It has been found in practice that ledges having a projection of from one-tenth
to one-fifth of an inch will permit the changing film to be readily forced past them
by the action of the stamping-through device, and will thereafter securely retain
the pack of exposed and deposited films within the receiving chamber. It has
furthermore been found advisable to cause the face of the stamping-through device
to pass beyond and within the ledges to a distance of from one-quarter to one-half
an inch.
The width of the receiving chamber, 5, and of that space, 18, above characterized
as a kind of hopper, into which the released film is dropped from the exposure
holder, should not greatly exceed the width of the films operated upon. It has
been found in practice that a clearance of from one-fiftieth to one-twentieth of an
inch is amply sufficient to permit the films to drop freely into the hopper, and to.
assure their being thereafter securely retained in the receiving chamber.
It is obvious that the stamping-through device may be operated from the outside
of the camera case in any convenient manner other than that illustrated in the
appended drawings, as, for instance, by a link attached to a rotating rod passing
transversely through the camera case. It will likewise be apparent that the devices
for effecting the selection and separation of the foremost film may be connected
with the stamping-through device in such wise as to be operated together with it
by one movement of a handle upon the outside of the case.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. In a film changing photographic camera the construction of a chamber for
the reception of the exposed and deposited films having upon two or more of
its sides the retaining ledges, 3, substantially as and for the purpose hereinbefore
described.
2. In a film changing photographic camera the combination with a receiving
chamber having ledges, 3, of a stamping-through device such as 1, by means of
which the films to be deposited are so bent and forced past the said ledges as
to be retained by them in a secondary pack or series, substantially as hereinbefore
described.
3. In a film changing photographic camera the combination with a receiving
chamber having ledges, 3, and with a stamping-through device such as 1, of a
secondary spring pressure board, 22, in the receiving chamber, the said pressure
board, 22, being compressed by the thrust of the stamping-through device and

page_text: serving to retain the pack of deposited films in the receiving chamber under
constant pressure: alternately against the face of the stamper, 1, and against the
ledges, 3, substantially as herein before described.
Dated this 14th day of January 1895.
JOSEPH THACHER CLARKE.