Improvements in Photographic Cameras.
Year: 1895

page_text: Date of Application, 20th Nov., 1895
Complete Specification Left, 20th Aug., 1896-Accepted, 3rd Oct., 1896
PROVISIONAL SPECIFICATION.
Improvements in Photographic Cameras.
We, JOHN EDWARD THORNTON and EDGAR PICKARD, both of Altrincham,
near Manchester, in the County of Chester Manufacturers, do hereby declare the
nature of this invention to be as follows:-
This invention is designed for the purpose of making the ordinary tripod type of
camera such as is well known as the "Thornton Pickard Ruby Camera" capable
of being readily used as a hand camera without altering the general construction
or interfering with its application to a tripod, also to render it more convenient in
use either when used on a tripod or in the hand.
The invention applies to improvements in various parts and details of the camera
all of which combined give the result anticipated.
The stretchers by which the back and front of the camera are held in upright or
erect position we construct with a deep notch in the side of the ordinary longitudinal
slot, this slot extending both above and below the notch. The notch is placed in
such a position that when the pin engages in it the front or back is perpendicular
to the base and is sufficiently deep that the pin cannot slip out until the stretcher
is moved and the slot extending above the notch allows the upright part to swing
beyond the perpendicular. A spring is attached at the bottom pivoted or hinged
end of the stretcher and abuts or acts against the plate to which it is pivoted or is
arranged in any other convenient manner. The function of this spring is to cause
the stretcher to automatically move to one side as the camera is raised or opened
out and cause the deep notch in the side to engage with the guide pin as soon as the
front and back respectively are perpendicular with the base. In combination with
the deep notch in the stretcher side we employ a clamping screw or nut by which
the stretcher can be secured while the pin is in the notch or in any other position
to place the front or back at any desired inclination to the base plate.
this arrangement as the camera is opened the front and back at once assume a
perpendicular position without any adjustment or necessity for clamping the
stretchers in position which is very necessary for hand use while for tripod use the
clamping screws can also be secured to render the camera more rigid or when
desired to place the upright parts at a different angle.
By
At
The fork carrying the rising front board is constructed in the usual way.
the bottom of the fork at one side we attach a plate with an open ended slot at the
bottom edge.
This slot is made of keyhole shape through half the thickness of
the plate or the upper end of the slot is countersunk at one side so that the head
of a pin or screw after entering the slot will act to prevent the plate from being
withdrawn. A pin or stud with suitable shaped head is affixed to the inner side of
the extension frame and is provided with a spring which is compressed when the
slot in the plate is pressed over the shank of the pin but acts when the head of the
pin reaches the enlarged or countersunk part to force the plate outwards and thus
hold it in position until the spring is again compressed. On the other side of the
front the arrangement is reversed. By this arrangement the fork is so fixed that it
cannot be removed until it is moved laterally a sufficient distance to compress the
spring and release the head of the pin from the countersunk end of the slot.
The extension frame is moved to and fro for focusing in the usual way by a rack
and pinion two sets of pinions one at the front and one at the back being preferably

page_text: employed. One or both of the pinions we provide with a clamp or clamping
device so that it can be made fast at any desired point. This clamp is constructed
with a small eyebolt encircling the spindle of the pinion with a washer or loose
gripping piece inserted at the other side against which a clamping nut bears. By
screwing up the nut the eve is drawn towards it and the washer moved in the
opposite direction the spindle being clamped between them. The nut is grooved
or recessed to fit against the spindle and to pass over the eye of the bolt. The
clamping nut is preferably placed beneath the base board which is recessed to
receive the clamping washer. By this means the extension frame can be set in any
position or to focus at any given distance and then firmly secured.
The camera back and body slides forward upon the base board as usual but we
fit it with two or more catch springs therein which hold the parts against accidental
Inovement. The cross bar of the body mounts or passes over the inclined plane of
these springs depressing them when the body is pushed backwards until the cross
bar passes over the springs and gets behind them, it is thus held and any forward
movement prevented until the springs are purposely depressed.
In the focusing screen the frame which carries the ground glass plate is attached
to the reversible back of the camera by two long flat springs secured at their
centres to the reversible back. These springs are slightly curved outwards from the
centre and at one end are formed with or turned over into an eye and at the other
into a hook. Pins are fixed to the top and bottom edges of the ground glass frame
one set engaging with or being gripped by the eyes at one end of the springs and
the other ends of the springs resting upon the other set of pins so as to allow that
end of the frame being drawn away from the back to a considerable distance until
the pins engage with the hooks.
These springs hold the ground glass frame in close contact with the reversible back
keeping it up to accurate focus but allow of the frame being moved backwards to
admit the dark slide between it and the back. The eyes at one end of the spring
practically form hinges whilst the formation of the spring at the other end permits
it opening first the hooks limiting the movement prevent the springs being
strained.
Upon the reversible back we place two fixed rails standing above the back and
at a distance apart equal to the width of the dark slide. Near the centre of these
rails two metal plates are fixed which project beyond their inner edges. The
ground glass frame fits between these rails and is cut away to avoid the projecting
edges of the metal plates so that it may be close against the back.
The dark slide is made of any ordinary pattern with rabbeted or grooved edges
it fits in between the rails and between the ground glass frame and the back the
edge fitting under the metal plates which hold it closely in position against the
reversible back. The metal plates also serve the purpose of preventing light
entering the camera should the ground glass frame be accidentally pulled away
when the slide is in position.
The edge of the dark slide is provided with a notch and a small flat spring
carrying a pin (or other spring catch) is provided on the camera which engages
with the notch and prevents the dark slide being accidentally withdrawn after
being placed in position.
We place a strip of velvet (or other soft material) upon the reversible back and
upon the inner side of the ground glass frame to prevent the polished surface
of the dark slide being scratched.
The camera is provided with an enclosing or carrying case which is detachably
secured thereto in such a manner that it forms practically a part of the camera
opening and closing at the same time but can be entirely removed when desired.
It is made of wood, cardboard or other suitable material with leather, waterproof,
cloth or other suitable covering. It is constructed with a space behind the camera
for dark slides, magazine or roll holder and is fitted with a door at one side for the
purpose of inserting or withdrawing the dark slide and for removing the covering
shutter therefrom. This arrangement allows of the camera always being ready for

page_text: immediate use without unstrapping the carrying case and removing the camera
therefrom but the camera can be used without it on a tripod.
The base and extension frame are fitted in the usual way with a focusing scale
or scales of distances and a small finder is also provided as is customary in hand
cameras.
Dated this 15th day of November 1895.
The invention applies to improvements in various parts and details of the camera
all of which combined give the result anticipated.
It will be fully described with reference to the accompanying drawings.
Fig. 1. Side elevation of camera with parts in section.
Fig. 2. Longitudinal section of base of same on line x-y.
Fig. 3. Back elevation of same.
Fig. 4. Enlarged details.
Fig. 5. Plan of spring.
The stretchers A and B by which the back C and front D of the camera are
held in upright or erect position we construct with a deep notch a in the side of
the ordinary longitudinal slot a¹ this slot extending both above and below the
notch a.
The notch is placed in such a position that when the pin E engages in
it the front D or back C respectively perpendicular to the base F and is
sufficiently deep that the pin E cannot slip out until the stretcher is moved. The
Blot extending above the notch allows the upright part to swing beyond the
perpendicular. A spring G is attached at the bottom pivoted or hinged end of
the stretcher A or B and abuts or acts against the plate to which it is pivoted or
is arranged in any other convenient manner. The function of this spring G is
to cause the stretcher A or B to automatically move into position as the camera
is raised or opened out and cause the deep notch a in the side to engage with the
guide pin E as soon as the front and back respectively are perpendicular with the
base. In combination with the deep notch in the stretcher side we employ a
clamping screw or nut e by which the stretcher can be secured while the pin is in
the notch or in any other position to place the front or back at any desired
inclination to the base plate. By this arrangement as the camera is opened the
front D and back C at once assume a perpendicular position without any adjust-
nient or necessity for clamping the stretchers in position which is very necessary
for hand use while for tripod use the clamping screws e can also be secured to
render the camera more rigid or when desired to place the upright parts at a
different angle.
The extension frame H is moved to and fro for focusing in the usual way by a
rack K and pinion k two sets of pinions one at the front and one at the back being
preferably employed. One or both of the pinions we provide with a clamp or

page_text: clamping device so that it can be made fast at any desired point. This clamp is
constructed with a small eyebolt L embracing the spindle of the pinion k with a
washer or loose gripping piece linserted at the other side against which a clamping
nut bears. By screwing up the nut the eye is drawn towards it and the
washer moved in the opposite direction the spindle being clamped between them.
The washer is grooved or recessed to fit against the spindle and to pass over the
eye of the bolt. The clamping nut is preferably placed beneath the base board
which is recessed to receive the clamping washer 1. By this means the extension
frame H can be set in any position or to focus at any given distance and then
firmly secured.
The camera back C and the body N slides forward upon the base board O as
usual but we fit it with one two or more catch springs P therein which hold the
parts against accidental movement. The cross bar m of the body mounts or
passes over the inclined plane p of these springs depressing them when the body
is pushed backwards until the cross bar passes over the springs and gets behind
them it is thus held and any forward movement prevented until the springs are
purposely depressed.
In the focusing screen R the frame S which carries the ground glass plate T is
attached to the reversible back of the camera by two long flat springs U secured
at their centres to the reversible back. These springs are slightly curved outwards
from the centre and at one end are formed with or turned over into an eye u and
at the other into a hook u¹. Pins t are fixed to the top and bottom edges of the
ground glass frame S one set engaging with or being gripped by the eyes u at one
end of the springs and the other ends of the springs resting upon the other set of
pins so as to allow that end of the frame being drawn away from the back to a
considerable distance until the pins engage with the hooks u³.
These springs hold the ground glass frame S in close contact with the reversible
back keeping it up to accurate focus but allow of the frame being moved back-
wards to admit the dark slide W between it and the back. The eyes u at one end
of the spring U practically form hinges whilst the formation of the spring at the
other end permits it opening first the hooks u¹ limiting the movement prevent the
springs being strained.
Upon the reversible back we place two fixed rails Y standing above the back
and at a distance apart equal to the width of the dark slide W. Near the centre
of these rails two metal plates y are fixed which project beyond their inner edges.
The ground glass frame S fits between these rails and is cut away to avoid
the projecting edges of the metal plates so that it may be close against the back.
The dark slide W is made of any ordinary pattern with rabetted or grooved
edges. It fits in between the rails Y and between the ground glass frame S and
the back the edge fitting under the metal plates y which hold it closely in position
against the reversible back. The metal plates also serve the purpose of preventing
light entering the camera should the ground glass frame be accidentally pulled
away when the slide is in position.
The edge of the dark slide is provided with a notch w¹ and a small flat
spring W carrying a pin w³ (or other spring catch) is provided on the camera
which engages with the notch and prevents the dark slide being accidentally with-
drawn after being placed in position. We place a strip of velvet (or other soft
material) upon the reversible back and upon the inner side of the ground glass
frame to prevent the polished surface of the dark slide being scratched.
The base and extension frame are fitted in the usual way with a focusing scale
or scales of distances and a small finder is also provided as is customary in hand
cameras.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is.—
1. In a photographic camera the combination with the pinion k which operates

page_text: the extension frame H of an eyebolt L embracing the same a loose washer / and
a clamping nut a substantially as and for the purpose described.
2. In a photographic camera the combination with the back M body N and base
board O of one two or more catch springs P with which the cross bar m engages
to prevent accidental movement of the body substantially as described.
3. In a photographic camera the combination with the reversible back the
focusing screen R and two long flat springs U attached to the reversible back
formed with eyes u at one end and hooks u¹ at the other end to engage with pins
on the ground glass frame metal plates y which form guides or slides for the dark
slide the frame of the focusing screen being cut away to avoid the metal plates y
substantially as and for the purpose described.
4. In a photographic camera the combination with the dark slide W provided
with a notch w¹ of a spring catch W₁ carrying a pin w³ to engage with the notch
substantially as and for the purpose described and shown.
5. A photographic camera having the several parts constructed and arranged
in combination substantially as described and shown.
Dated this 19th day of August 1896.
WM. P. THOMPSON & Co.,
Manchester, Liverpool, and London, Patent Agents.