Improvements in Photographic Cameras.
Year: 1893

page_text: Date of Application, 15th June, 1893
Complete Specification Left, 16th Apr., 1894-Accepted, 12th May, 1894
Improvements in Photographic Cameras.
I ALFRED WILLMER POCOCK of 66 St. Ann's Hill Wandsworth in the
County of Surrey Engineer do hereby declare the nature of this invention to be as
follows:-
My invention relates to photographic cameras and consists of improvements in
the detail of construction as hereinafter described whereby they are rendered very
compact and portable and have no inconvenient projecting parts when closed and
out of use and whereby they are very easy to manipulate.
According to my invention I connect the front and back boards or ends of the
camera together by arms or frames pivotted to the front and back boards or ends
respectively and hinged together at their outer ends so as to admit of the camera
being readily opened out or expanded for use and closed or contracted.
Springs are arranged to act on the frames or arms so as to maintain the camera
firm and rigid when in its expanded and contracted positions. Adjusting screws are
also provided by which the extent of expansion of the camera may be governed
these screws also serving to adjust the focus of the camera.
The lens is mounted
in a ring fitted to slide in a tube capable of being rotated in another tube fixed to
the front board of the camera. The ring in which the lens is mounted has pins or
projections which enter helical slots in the rotating tube one or more of the said
pins or projections passing through one or more of the said helical slots into a
longitudinal slot or longitudinal slots in the fixed outer tube. The plate by which
the stationary outer tube is fixed to the front board is provided with segmental
slots through which pass screws, into a rim or flange formed on the rotating tube
80 as to connect the tubes together but admit of the inner tube being rotated
which may be effected by means of a projection formed on the flange of the said
inner tube. By turning the inner tube in the outer tube the helical slots by acting
on the pins or projections on the ring in which the lens is mounted will cause the
said lens to move longitudinally in the said tube and thereby the lens may be
readily focused. The lens and the focusing arrangemnt described are contained
behind the front board of the camera. On the interior surface of the front board
I arrange an improved shutter which consists of two pivotted plates arranged to
slide one over the other opposite the sight hole or lens opening in the front board
these plates being provided with openings and an operating device so arranged that
the exposure commences at the centre or axis of the lens and closes from the
periphery to the centre. The plates are connected together by crank arms and a
connecting rod so as to move simultaneously and one of the said plates is provided
with an additional arm- having a segmental piece with notches or projections or
both with one or other of which, spring detents are caused to engage to retain the
plates in the open or exposing position and also in the closed position.
To this additional arm is pivotted an arm or lever by means of which the shutter
is set for operation the end of which arm projects through a slot to outside the front
board this slot being provided at the opposite ends with notches in either of which
the said lever may be caused to engage. The arm to which this lever is pivotted
carries springs which have a bearing on opposite edges of the lever so that when
the lever is moved to one side or the other and engaged in one of the notches in
the ends of the slot, the corresponding spring is pressed out of its normal position

page_text: and tends to move the plates to their exposing position but is prevented from doing
so by the spring detents engaging the projections or notches on the segmental end
of the arm.
The arm may be released from the detents by depressing one or
other of the said detents from outside the camera.
By pressing one of these detents namely that which is provided with an addi-
tional projection, the shutter will, under the action of the spring be caused to open
and close instantly, but if it be desired to prolong the exposure, the detent not
provided with the additional projection is first depressed, whereupon the shutter
will open, but as the other detent has not been depressed the projection thereon
will remain in the track of a projection on the arm and will thereby prevent the
shutters from closing. To close the shutter the detent with the additional projec-
tion thereon must be depressed so as to remove the projection out of engagement
with the projection on the arm whereupon under the action of the spring the
shutter will immediately close.
The sensitised plates or films to receive the pictures are arranged one on top of
another in a case or chamber constituting a hollow dark slide which is slid and
fixed in the back board or end of the camera.
The
This dark slide consists of two cases fitted to slide one within the other.
outer case is closed on its four sides and at one end, whilst the inner case is closed
at one end and only three of its sides the other side being open to expose the
front plate of the set contained therein.
•
When the dark slide is inserted in the back board or end of the camera the
inner case is secured therein by a sliding bolt so that the outer case can be with-
drawn without the said inner case. To the exterior of one side or edge of the
inner case is secured a blade spring having a projection thereon which passes
through an opening in the said side and engages all the sensitised plates contained
in the case except that lying next to the open side of the case.
Inside the case is a thin plate having at its inner end a projection to engage the
edge of the front one of the sensitised plates and at its opposite end another
projection which engages all the plates contained in the case. This thin plate is
connected to a rod or bar situated outside the case by a pin which passes through
a slot in the case by means of which bar the thin internal plate may be drawn
outward and with it the front sensitised plate with which the projection thereon
engages. The sensitised plates are pressed towards the open side of this inner case
by springs so that when the front plate is withdrawn as described the rest of the
plates are pressed forward a space being thus provided at the back of the other
plates for the plate which had been withdrawn.
Before a plate can be withdrawn the outer case must first be drawn out
sufficiently to expose the front sensitised plate which outer case then forms a
receptacle for the plate which is withdrawn which plate assumes such a position in
the outer case that when the rod or bar connected to the inner slide is pressed
inward, the projection thereon, which engages all the plates, will force the with-
drawn plate into the space provided at the back of the other plates in the inner
case.
Springs may be arranged in the inner case or in the sliding case to pass the
plate which is withdrawn by the pusher into the proper position for being pushed
behind the other plates.
When all the plates contained in the case have been used the case may be
unbolted and removed from the camera and replaced by another case containing a
supply of unused plates.
A hook or bolt may be provided for the purpose of locking the outer case of
the dark slide to the inner case and situated or arranged so that by the act of
securing the inner case to the back board of the camera by the bolt provided for
that purpose the said bolt is caused to act on the hook or bolt so. as to unlock the
outer case to admit of it being withdrawn to expose the front sensitised plate and
by moving the bolt to detach the dark slide from the back board of the camera
the said bolt will cause the hook or bolt to be moved so as to connect the outer

page_text: case to the inner case of the dark slide which can then be removed from the
camera without danger of opening it accidentally during removal.
Dated this 15th dox of June 1893.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in Photographic Cameras.
I, ALFRED WILLMER POCOCK of 66 St. Ann's Hill, Wandsworth in the County
of Surrey, Engineer, 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 relates to photographic cameras, and consists of improvements in
the detail of construction as hereinafter described, whereby they are rendered very
compact and portable and have no inconvenient projecting parts when closed and
out of use, and whereby they are very easy to manipulate.
1 will describe my invention with reference to the accompanying drawings
Figure 1 of which represents in side elevation a photographic camera constructed
according to my invention, the camera being in its open or expanded position.
Figure 2 is a front elevation with the case removed.
Figures 3, 4 and 5 are views of my improved shutter in different positions.
Figures 6, 7 and 8 are respectively a side elevation, a section, and a plan of the
lens focussing device.
Figure 9 is a longitudinal section of the magazine dark slide, and Figure 10 is
a plan of the same partly in section.
The front board or end A and the back board or end B of the camera are
connected together by arms or frames C pivotted at a and b to the said front and
back boards or ends respectively, and hinged together as shewn at c so as to admit
of the camera being readily opened out or expanded for use and closed or
contracted.
The camera is maintained firm and rigid by springs D fixed to the front and
back boards one only of which springs is shewn in Figure 1 secured at d to the
back board B. These springs press on pins e arranged on the frames C, at one side
of the pivots a and b on which the frames turn.
To further ensure the rigidity of the camera when expanded, a stretcher bar E
may be provided having slots with notches therein to engage studs g on the
frames C. The bar E is made in two parts screwed together so as to be capable
of being lengthened and shortened as required according to the degree of extension
of the camera.
When the camera is closed or contracted the springs D by pressing on the pins €
(which are then on the opposite sides of the fulcrums or pivots a b) maintain the
camera in its closed position.
-
The extent of expansion and consequently the focus of the camera is governed
by adjusting screws i against which, projections or tail pieces on the frames C
come into contact. The lens F is mounted in a ring k see Figures 6, 7 and 8 fitted
to slide in a tube / which is capable of being rotated in another tube m fixed to the
front board or end A of the camera. The ring khas pins or projections n which
enter helical slots o in the rotating tube l, one or more of the said pins - or
projections n passing through one or more of the said helical slots o into a
The stationary
longitudinal slot or longitudinal slots p in the fixed outer tube m.
outer tube m is fixed to the front board, and is provided with segmental slots
through which pass screws into a rim or flange s formed on the rotating tube l, so
as to connect the tubes m and together but admit of the tube 1, being rotated by
means of a projection & formed on the flange of the tube as shewn. By turning

page_text: 11
On
the tube in the tube m, the helical slots in the tube / by acting on the pins or
projections n on the ring k cause the said ring with the lens to move longitudinally
in the tube whereby the lens may be readily focussed. The lens and the focussing
arrangement described are arranged behind the front board A of the camera.
the interior surface of the front board A is arranged an improved shutter consisting
of two pivotted plates and vas shewn more clearly in Figures 3, 4 and 5 arranged
to slide one over the other opposite the sight hole or lens opening G in the front
board A, these plates u and being provided with openings u² v² and an operating
device so arranged that the exposure commences at the centre or axis of the lens
and closes from the periphery to the centre thereof. The plates u and v are
connected together by crank arms wx and a connecting rod 22 so as to move
simultaneously one with the other. One of those plates (the plate v is provided
with an additional arm y having a segmental end z with projections or notches 1, 2
with which notches or projections a spring detent 3 is caused to engage to retain
the plates u v in the set position another detent 4 being caused to engage a pin or
projection 4* on the segment z to retain the plates in the open or exposing
position.
On the pivot 5 on which the plate turns is an arm y' which serves as a
lever by which to set the shutter for operation. The end of this arm y² projects
through a slot to outside the front board A and the said slot is provided with
notches 6 and 7 in either of which the said lever may be caused to engage. On
the pivot 5 are also mounted two arms 8 and 9 provided with projections which
bear on opposite edges of the arms y and y' and are connected by a spring 10
which when the lever is moved to one side or the other and engaged in one or
other of the notches 6 or 7 is expanded and then tends to more the plates u and v
to their exposing position but is prevented from doing so by the projection 11 on
the spring detent 3 engaging the projection or notch 1 or 2 on the segmental end =
of the arm y.
The arm y may be released from the projection 11 on the detent 3
from outside the camera by pressing on the end of the said detent which projects
through an opening in the case. The detent 4 is provided with a projection 12
which is in a position to engage the projection 4× on the segment z to retain the
shutter in the exposing position but by depressing the projecting end of this detent
the projection 12 thereon will be moved out of the track of the projection 4* so
that the shutter will under the action of the spring 10 be caused to open and close
instantly. If it be desired to prolong the exposure the detent 3 is first depressed
whereupon the shutter will open, but as the other detent 4 has not been depressed
the projection 12 thereon will remain in the track of the projection 4* on the
segment z and will thereby prevent the shutter from closing. To close the shutter
the detent 4 must be depressed so as to remove the projection 12 out of engagement
with the projection 4*, whereupon under the action of the spring 10 the shutter
will immediately close.
This
The sensitised plates or films to receive the pictures are carried in trays H
arranged one on top of another in a case or chamber constituting a magazine dark
slide, which is slid and fixed in the back board or end B of the camera.
dark slide consists of two cases I K fitted to slide one within the other. The outer
case I is closed on its four sides L M N O and at one end, whilst the inner case K
is closed at one end P and has one of its sides open to expose the front plate of the
set contained in the case. When the dark slide is inserted in the back board or
end B the inner case K may be secured therein by a sliding bolt T so that the
outer case can be withdrawn without moving the said inner case. Fixed to the
exterior of each side or edge RS of the inner case is a blade spring U having
projections V thereon which pass through openings in the said sides and engage all
the sensitised plates contained in the case except that one which is next to the open
side of the case.
Inside the case K is a thin metal plate or two thin metal plates W as shewn in
the drawing each plate having at its inner end a projection X to engage the edge
of the tray which is not engaged by the projections V. These thin metal plates W

page_text: when two are employed are connected together by a transverse plate 13 to which
is connected another plate 14 having a projection 15 thereon which engages all the
trays H containing the sensitised plates in the case K. When one thin plate W,
only is employed the projection 15 is carried on the said plate. To the transverse
plate 13 is connected a rod or bar Y situated outside the case K, by means of
which bar Y the thin plate or plates W may be drawn outward and with it the
front tray H (with the sensitised plate) with which the projection ✗ engages.
The trays H containing the sensitised plates are pressed towards the open side of
the inner case K by springs Z so that when the front plate is withdrawn as
described the rest of the plates are pressed forward, a space being thus provided at
the back of the other trays H for the reception of the tray carrying the plate
which has been withdrawn.
Before a plate can be withdrawn the outer case must first be drawn out
sufficiently far to expose the front sensitised plate which outer case then forms a
receptacle for the plate which is to be withdrawn. The withdrawn plate assumes
such a position in the outer case that when the rod or bar Y is pressed inwards the
projection 15 thereon will force the withdrawn plate into the space provided at the.
back of the other plates in the inner case K.
If desired springs may be provided in either case I or K to press the withdrawn
plates into proper position for being pressed by the projection 15 into the space
behind the other plates in the case K.
1
When operating with this camera it is first opened out or expanded until the
tails on the frames C come into contact with the 'screws which have been.
previously adjusted to the desired focus of the camera the focus of the lens being
also adjusted by turning by means of the levert the tube in the tube m the lever t
being connected to the tube m and projecting through an opening in the front.
board A. The dark slide being charged with sensitised plates is then inserted in
the back board B and secured therein by the bolt T engaging a projection on the
inner case K. The view having been determined the camera is placed in position
and the case I of the dark slide drawn out until a projection or projections 16.
thereon comes or come against a stop 17 on the spring plates U carrying the
projections Y, in which position the front sensitised plate in the case K is.
uncovered. The shutter is then set by placing the arm y in one of the notches 6.
or 7 say for example the notch 7 as shown in Fig. 3 thereby stretching and putting-
tension on the spring 10 and causing the projection 11 on the detent 3 to engage.
the notch 2 in the segment . If an instantaneous exposure be required the
projecting end of the detent 4 must be pressed inward the opposite end of which
will then act on the detent 3 so as to remove the projection 11 thereon from the
notch 2 on the segment z whereupon the plates u and v under the contracting action
of the spring 10 will be caused to pass rapidly over each other and as the openings.
in the said plates pass each other cause only an instantaneous exposure of the
front plate in the case K, to the action of the light passing through the lens.
If a time exposure be required the shutter is set as before but instead of pressing
the detent 4 the detent 3 is first depressed thereby releasing the projection 11 from
the notch 2 in the segment z whereupon the plates u and v under the action of the
spring 10 will slide over each other into the position shewn in Figure 4 the
openings in the plates then coinciding and being opposite the lens so that the front
sensitised plate in the case K is exposed to the light passing through the said lens
the plates
u v being retained in this position by the projection 4* on the segment z
engaging with the projection 12 on the detent 4. When the time for the required
exposure has expired the detent 4 is pressed thereby removing the projection 12.
from engagement with the projection 4* whereupon the plates uv under the action
of the spring 10 will complete their movement into the closed position shewn in
Figure 5.
The front sensitised plate having received the picture the bar Y is drawn outwards.
by means of the projection Y* the said front plate being at the same time drawn
outwards by the engagement therewith of the projections X on the plates W,.

page_text: which are connected to the bar Y, the withdrawn plate being deposited into the
outer case I, while the rest of the plates in the case K are pressed forward by the
springs so as to leave a space behind them for the reception of the plate which
had been withdrawn. The bar Y is then pushed inwards whereupon the pro-
jection 15 on the plate 14 forces the sensitised plate from the outer case I into the
space behind the sensitised plates in the case K.
When all the plates contained in the case have been used the dark slide, may be
unbolted and removed from the camera, and replaced by another containing a
supply of unused plates. The inner case K can be detached and removed from
outer case I by depressing the spring plates U so as to disengage the stops 17 from
the projections 16 the inner case can then be slid out of the outer case and the
plates removed therefrom and charged with a fresh set ready for use.
The bolt by which the dark slide is secured to the back board B may be double
acting that is to say, it may be so arranged that when the slide is detached from
the back board B, the two cases I and K will be bolted together by the said bolt
so as to prevent them being accidentally opened when being removed from the
camera and when the slide is inserted in the back board the bolting of the inner
case K to the said back board will cause the bolt to release the outer case I from
the inner case so as to admit of the outer case being drawn out.
*
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. The combination and arrangement of parts constituting the improved
photographic camera substantially as herein before described and illustrated by the
accompanying drawings.
2. An expandable and contractable camera having the front and back boards or
ends connected together by hinged arms or frames in combination with springs
acting on the armis or frames, to retain the camera rigid in its open or expanded
position and also in its contracted or closed position substantially as hereinbefore
described and illustrated in the accompanying drawings.
3. An expandable and contractable camera having the front and back boards or
ends connected together by hinged arms or frames in combination with springs
acting on the arms or frames, to retain the camera rigid in its open or expanded
position and also in its contracted or closed position and adjusting screws to
regulate the extent of expansion of the camera substantially as hereinbefore
described and illustrated in the accompanying drawings.
4. The combination and arrangement of parts constituting a shutter for
photographic cameras which is capable of use for either instantaneous or time
exposure substantially as hereinbefore described and illustrated in Figures 3, 4
and 5 of the accompanying drawings.
5. A magazine dark slide for photographic cameras consisting of two cases
arranged to slide one over the other without withdrawing a sensitized plate and
means whereby each sensitized plate can be withdrawn when required from one
case into the other case and reinserted into the case from which it had been
withdrawn, behind the other plates contained therein without exposing it to light
substantially as hereinbefore described.
Dated this 14th day of April 1894.
JOHNSONS & WILLCOX,
Agents.