Improvements in or relating to Changing Slides for Photographic Cameras.
Year: 1888

page_text: Date of Application, 15th Dec., 1888
Complete Specification Left, 13th Sept., 1889-Accepted, 15th Jan.,
1890
PROVISIONAL SPECIFICATION.
Improvements in or relating to Changing Slides for Photographic
Cameras.
I, HENRY HERBERT of 119 Hartfield Road, Wimbledon, in the County of Surrey,
Electrical & Photographic Instrument Maker do hereby declare the nature of this
invention to be as follows :—
The object of this invention is to provide means whereby a considerable number of
plates, say for example a dozen, can be carried exposed and changed in one apparatus
instead of the two plates usually carried in the ordinary dark back.
In carrying this invention into effect I provide a suitable box or case which may be
adapted to slide in the back of the camera or in a separate frame of its own which
may be attachable to the camera in the ordinary way or may be used separately where
required. The sliding box is made of suitable size and shape and contains the
required number of plates whether exposed or not and is preferably provided with a
closing shutter and a narrow slit or opening at the inner end through which each
plate as it is required for use can pass. This opening may be closed with an
automatic shutter which upon the removal of the case from its frame or the camera at
once closes the opening and prevents the entrance of light into the case. Iri the back
of the camera or frame I prefer to provide a spring controlled hinged plate or
equivalent device preferably of wood which is pressed back into a suitable recess or
receptacle upon the insertion of the sliding case and upon the withdrawal of the case
springs forward.
In using this apparatus the sliding case is first charged in the usual manner with
the sensitized plates and is then inserted into the frame or camera the automatic
shutter withdrawing from the aperture in the end of the case as it enters. The case
having been pressed home and it being desired to place the plate in position for
exposure the case is withdrawn, the bottom plate passing through the slit in the
casing and remaining in the camera or frame as the case is withdrawn. The spring
back is locked by a suitable detent but when the sliding case is withdrawn sufficiently
far from the frame or camera the detent is automatically released and the spring back
then moves the plate forward to its proper position for exposure where it is held
securely by the sliding case which is now returned into the frame or camera. After
exposure the sliding shutter is withdrawn and the plate falls back into the sliding
case with the other plates; the shutter is theu closed again. To expose the next
plate the sliding case is withdrawn as before leaving the next plate in the frame, this
is brought forward as already described and the sliding case is again returned and
after exposure the second plate is replaced in the case by the withdrawal of the
sliding shutter as before and so on until all the plates have been exposed when the
sliding case may be removed and a new one already charged substituted, or the sliding
case can be relieved of the exposed plates in the dark room recharged with fresh plates
and replaced as before.
In the frame or camera at the opposite end to that by which the sliding case enters
I prefer to have a spring controlled rising bottom carrying two suitable guides so
arranged that when the plate is pushed forward by the hinged back it must of
necessity come into the right position for exposure. When the sliding case is inserted
it pushes back the rising bottom.
1
.
1000

page_text: COMPLETE SPECIFICATION.
Improvements in or relating to Changing Slides for Photographic
Cameras.
HENRY HERBERT Ebor House Grove Park Road Chiswick Photographic and
Electrical Instrument Maker 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 :-
My invention has for its object certain improvements hereinafter set forth in
Photographic Apparatus which shall be applicable for use for changing dry plates or
in other words for substituting justo plates for those which have been exposed in the
progress of photography, and at the same time removing such exposed plates to
another and different position (in relation to the bulk of plates) to that which they
before occupied.
As an example of the application of my invention I will describe an apparatus
constructed in accordance with the above purpose.
It consists essentially of a box, case, or drawer (B) herinafter called the inner box
of suitable dimensions and material and of such a nature that it may slide light-tight
in and out of another box case or drawer herinafter called the outer box (A). The
inner hox is provided with a moveable side (C) which may be drawn in and out at
pleasure within limits, it being prevented from coming quite detached by suitable
metal stops, or it may be arranged to come right out if desired, in which case a
suitable valve must be supplied to prevent the ingress of light to the inner box. The
inner box is provided likewise with grooves (✗) commencing at the end from which
the moveable side or shutter is withdrawn, and being continued for a suitable distance
downwards, at which point a metal piece (Y) is inserted for greater strength, the
object of these grooves will be stated when describing the outer box. The inner box
is also provided with a handle for withdrawing from and inserting into the outer box
and may have an arrangement for locking the plates tight, which shall consist of a
piece of wood or other material, furnished with a strip or strips of leather or india-
rubber and a moderately powerful spring behind which presses it hard against the
edge of the platos, this is situate inside the inner box at the end at which the sliding
shutter enters and may communicate with the handle in such a way that on pulling
the latter the spring board is automatically removed or thrown out of action, to be
once more replaced on relinquishing hold of the handle. On the outside of the inner
box and at the opposite end of the box to which the sliding shutter enters is a metal
piece (Z) which is moveable backwards and forwards over a slot which runs the
length of the end of the inner box at the back or further side of the box (that is at
the opposito side of the box to which is closed by the shutters) this slot is only of
sufficient width to allow one of the photographic plates to pass at a time, and the
object of the metal piece is to close the slot light-tight when necessary, this pieco
being removed from its position on inserting the inner box into the outer one, by
means of two projecting piecos (0, 0) which engage in or are acted upon by guide
strips attached to the inner side of the outer box, under these circumstances the slot
admits the passage of one of the plates from the inner to the outer box, but on with-
drawing the inner box the metal piece resumes its position (by means of a spring (S))
and closes the slot.
This arrangement is intended to provide means whereby one inner box with its
compliment of sensitive plates may be withdrawn in the light from the outer box and
another substituted thus allowing an indefinite number of plates to be changed by
means of duplicate inuer boxes and one outer box.
The outer box is in the first place provided with suitable pieces (P, P) which when
desired fit into the grooves on the inner box and prevent its being withdrawn beyond
a certain point, but may be removed when the inner box is to be quite withdrawn and
replaced by another, these pieces together with the grooves will be herinafter called
the box-stops.

page_text: At the inside of the outer case and at the bottom or at the end further from that at
which the inner case enters is a platform (D) provided with springs which keep it
normally in a position coincident with that of a rebate which runs round the inner
side of the outer box and which is intended to hold the plate in position for exposure.
5 This platform may be provided with small guides which shall include a space equal to
one of the dimensions of the plate. The object of this platform with its guides will be
described when explaining the action of the apparatus in use.
At the back of the outer case and on the inside there is a flap or leaf (L) which is
kept normally by a spring pressed forward against the plate to be exposed and works
on hinges situate at such a position that immediately on inserting the inner case the
tension of the spring flap is overcome and it folds back into a recess provided for it,
and there remains until the inner case is once more withdrawn to a certain extreme
point, when it once more springs forward into its former position. The method of
using this apparatus is as follows:-
The inner case is withdrawn and charged with sensitive plates by opening the
shutter, and introducing the plates one by one, in every case keeping the sensitive
surface towards the shutter. This shutter is then pushed home and the inner box
placed in the outer one in a horizontal position with the shutter uppermost, it is then
held perpendicularly with the handle upwards and the stops being in position the
inner box is withdrawn to its limits. The valve or metal piece being thus auto-
matically removed as before described the back or rear plate passes through the slot
into the outer case and assumes a position between the guides and on the platform
which is now in position ready for the plate to be pushed forward into the rebate as
before. This is done by the spring flap which is released by virtue of the position of
the inner case.
The plate being now within the rebate the inner case is pushed home and in its
descent, it first pushes back the spring flap (passing between this and the plate) and
then the spring platform at the bottom. The plate having now been exposed the
apparatus is held again in a horizontal position and the shutter withdrawn, this allows
the plate to fall into the inner case once more, but on the opposite side of the bulk of
plates to that which it formerly occupied, the sensitive side however still retaining its
position in relation to the shutter. These processes are repeated so long as any of the
plates remain unexposed, but when all the plates contained in the inner box have in
turn been exposed and changed, the inner box is withdrawn, the metal piece or
valve automatically closing the slot, and on another inner case being inserted the
valve of this one is likewise automatically opened.
REFERENCES TO THE DRAWINGS.
Fig. 1 (Sheet 1) represents the apparatus with the inner box withdrawn-the
framework being shown at A. the box-stops at P. P. The spring-back and the spring
platform are seen at L and D. respectively.
Fig. 2 (Sheet 1) illustrates the inner box with the shutter (partly open) at C. and
the grooves for engaging with the stops (P. P. Fig. 1) at X terminating at the metal
piece Y. The metal piece Z and its lugs O. O. are more clearly shown at Figs. 1
and 2 (Sheet 2) in which the action of Z is denoted by its different position with
regard to the box.
Figs. 1 and 2 (Sheet 3) show the action of the spring flap (T) and the platform
with its guides (K) under the influence of the inner case, as also the method by which
the plate (Q.) and (S.) is hold in position by the insertion of the inner box. The
handle (V) Fig. 2 (Sheet 3) explains the method of locking the plates tight when
travelling. At (R) Fig. 3 (Sheet 3) the section of spring platform (with the plate (P)
represented by the thick black line) is shown at its highest point. The ends of the
receding inner case being denoted by the shaded portions (G. G).
Fig. 1 (Sheet 4) represents an inside view of the outer box with the section of
metal piece (Z) and its lug (0) as moved to (Z) and (O¹) by the action of the bent
channel (I). The shaded portion of this figure represents the sectional view of the
inner case in the action of entering the outer one.

page_text: Fig. 2 (Sheet 4) shows the method of attaching the changing-box to the photo-
graphic camera as used for detective cameras and for the smaller sizes, as will be seen
by the section of the camera, it is-joined permanently to the box. For larger sizes
the change-box is provided with grooves to engage with a rebate or fillet on the
camera precisely in the same manner as an ordinary dark slide. The method, of
exposing the plate differs in no wise from the methods usually adopted when using an
ordinary dark-slide and camera.
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 :-
--
First. In a photographic plate changing apparatus the use of a compound box or
caso consisting of a removable inner case provided with a shutter for the return
passage of exposed plates and a slot for the ontward passage of unexposed plates,
which slides within an outer case furnished with suitablo guides and springs for
guiding and pushing the plate (after its having left the inner box) into a position
suitable for exposure, such guides being automatic in their action, or in other words
actuated by the mere withdrawal or insertion of the inner box.
Second. In a plate changing apparatus of the type herein described the holding of
such apparatus in such various positions that terrestrial gravity shall actually determine
the movement of tho plates in their various passages through slot and shutter herein
described.
Third. In a plate changing apparatus of the type horein described the use of an
automatic valve or light-trays by means of which a number of plates contained in a
light-tight case may be withdrawn in full daylight and another similar light-tight case
substituted ad infinitum.
Fourth. In a plate changing apparatus of the type herein described the use of a
spring platform or guides having for its object the guidance of the plate from the rear
to the front of the plate changing apparatus.
Fifth. In a plate changing apparatus of the type herein described the use of a
spring flap which shall be brought into action automatically on withdrawing the bulk
of plates contained in a box to allow of the plate being pushed forward.
Sixth. In a plate changing apparatus of the type herin described, and in connection
with the valve (constituting my claim No. 3) the use of suitable pushes or projecting
pieces attached to or forming part of the said valve, and which shall work in or engage
with a bent guide or channel affixed to or cut in the inner surface of the outer box,
and made or fitted in such a manner that as the inner box with its attendant valve and
pushes or pieces belonging thereto is pushed or forced into the outer box the above
pieces shall (by virtue of their slanting or angular position) act in a direction contrary
to that of the spring hereinbefore described, thus opening the valve or metal piece to
allow the exit of a plate through the slot.
Seventh. In a plate changing apparatus of the type herein described the uso of a
spring board for the purpose of holding the plates tight when travelling and consisting
of a board in the upper part of the inner case and pressed normally forward by
suitable springs and furnished with a rod or handle which passes through the end of
the inner case and terminates in a handle or knob which is used for inserting and
withdrawing the inner case.
T
1000