Certain Improvements in Change Boxes of Photographic Cameras.
Year: 1895

page_text: Date of Application, 22nd Mar., 1895
Complete Specification Left, 13th Dec., 1895-Accepted, 18th Jan., 1896
PROVISIONAL SPECIFICATION.
Certain Improvements in Change Boxes of Photographic Cameras.
I, EDWIN UNDERWOOD, trading as E. & T. Underwood, of 130 and 132 Granville
Street, Birmingham, Warwickshire, Photographic Apparatus Manufacturer, do
hereby declare the nature of this invention to be as follows:-
This invention has reference to change boxes of photographic cameras and
consists of the hereindescribed improved means for indicating the number of
exposed and unexposed plates in the camera and for manipulating the said plates
therein so that they will be exposed one after the other in regular order and after
exposure will successively fall to or towards the bottom of the camera out of the
way of the next unexposed plate.
For the purposes of my invention the sheaths which carry the plates rest on
horizontal side bars fixed to the inside of the change box at some little distance
above the bottom of the same and they are as usual pressed forward by a spring
at the back of the change box. Arranged to he turned in a bearing in the top
of the change box I provide a metal or other suitable disc inside the change box
the said disc being made with two sets of teeth projecting from its inner face
these teeth being arranged in two concentric circles oue within the other but
leaving an annular space between the two circles of teeth. The said disc is
arranged to be turned by a finger on the outside of the change box and in
connection with this finger there is a dial divided off into an equal number of
parts corresponding with the number of plates, say twelve, which the change box
is required to hold, so that as hereinafter described this finger will indicate on the
dial the number of plates which have been exposed in the change box and will
also shew the number of unexposed plates therein. Each of the sheaths has a
small projection at its upper edge adapted to rest against the teeth of the disc
and also to pass through the notches or spaces between the said teeth. Each
sheath has side pivots at its bottom edge (preferably formed of a double cranked
wire fixed to the sheath) which side pivots in turn come against stops formed at
the inner ends of the guide bars in the camera on which the sheaths rest.
box
The action of the mechanism above described is as follows:-The change
having been charged with say for instance twelve plates in corresponding sheaths.
the finger by which the disc is turned is set to indicate "1" and the said pins at the
bottom of the front sheath rest against the stops on the guide bars and the projection.
at the top of this sheath passes through one of the notches between the larger
circle of teeth and rests against one of the teeth in the smaller circle. The first
plate is now in position to be exposed. After this plate has been exposed the said
finger is turned through a small angle thereby correspondingly turning the disc so
that the projection on the top edge of the front or exposed plate will now pass
through one of the notches between two of the teeth of the smaller circle and the
sheath and plate will then fa'l down to the bottom of the camera turning on its two
bottom side pins as centres the forward fall of the plate being broken by the usual.
light spring frame hinged near the top of the camera which is pressed forward by
the plate in falling and then springs backwardly again ready for the next plate..
The turning of the disc as aforesaid to release the first plate simultaneously
brings one of the teeth of the outer circle in position for the projection on the top.
edge of the second sheath to rest upon until the first sheath has fallen and then
the continued movement of the disc until the finger indicates "2" allows of the

page_text: projection on the top of the second sheath passing through one of the inlets
between the larger circle of teeth so as to rest against one of the teeth in the
smaller circle and thus bring the second plate in position ready for exposure. Thus
by turning the finger on the outside of the camera the exposed plates are succes-
sively allowed to fall down out of position and a new plate is moved in position to
be exposed, the finger indicating on the dial the number of plates which have been
exposed and the number of unexposed plates in the camera.
Dated this 21st day of March 1895.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.
Certain Improvements in Change Boxes of Photographic Cameras.
I, EDWIN UNDERWOOD, trading as E. & T. Underwood, of 130 and 132, Granville
Street, Birmingham, Warwickshire, Photographic Apparatus Manufacturer, 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 has reference to change boxes of photographic cameras and
consists of the herein described improved means for indicating the number of
exposed and unexposed plates in the camera and for manipulating the said plates
therein so that they will be exposed one after the other in regular order and after
exposure will successively fall to or towards the bottom of the camera out of the
way of the next unexposed plate.
I will describe my invention by referring to the accompanying drawing on
which
Fig. 1 is a part sectional elevation of the change box part of a photographic camera
with my invention applied thereto; Fig. 2 is a projected view of the lower part of
the same;
Fig. 2 shews the upper part of one of the sheaths;
Fig. 3 is a sectional elevation of my invention; Fig. 3* is a side elevation of
the same; Fig. 4 is a plan of the same; Fig. 5 is an inverted plan of the same;
Figs. 6, 7 and 8 illustrate the operation of my invention as hereinafter described.
The same letters of reference indicate the same parts in all the figures of the
drawing.
For the purposes of my invention the sheaths which carry the plates, and which
are marked respectively A¹ A2 A³ A'A' A' A' A8 A° A¹º A¹¹ A12, rest on horizontal
guide bars B fixed to the inside of the two sides of the change box C at some little
distance above the bottom of the same and the sheaths with the plates are as
usual pressed forward by a spring D at the back E of the change box. Each
sheath has two side pivots one at each side of its bottom edge marked a¹ (preferably
formed of double cranked wire fixed to the sheath as shewn in Fig. 2) which side
pivots a come in turn against stops b' formed on the inner ends of the guide
bars B. These angle bars B and the sheaths are old and I make no claim in respect
of them.
In order to indicate the number of exposed and unexposed plates in the camera
and also to expose the plates one after the other in regular order and cause the
plates to successively fall after exposure on or towards the bottom of the camera
out of the way of the next unexposed plate, I provide a metal or other suitable
disc Finside the top of the change box C and provided with a central pin f¹
which passes through bearings g in the circular index plate G which is let into
the top of the camera, and fixed to this central pin there is a finger H on the

page_text: outside of the change box by which the pin f1 and the disc F can be turned. The
disc F is made with two sets of teeth marked respectively I and J projecting.
from its inner face these teeth being arranged in two concentric circles the teeth .J
forming the inner circle and the teeth I forming the outer circle and leaving an,
annular space K between the two circles of teeth. Between each of the teeth I.
there is a space L which spaces come opposite to the teeth J of the inner circle,..
and similarly between each of the teeth J there is a space M which spaces are
arranged opposite the teeth I of the outer circle. There may be any convenient.
number of teeth in the two circles as for instance twelve as shewn on my drawing
corresponding with the greatest number of plates and sheaths which the change box...
is designed to hold. In connection with the finger H by which the disc is turned,.
there is a dial 92 formed on the circular plate G and divided off into an equal,
number of parts corresponding with the number of plates say twelve which the-
change box is required to hold, and in this case they are numbered respectively 1
to 12, as shewn in Fig. 4, so that as hereinafter described the finger H will
indicate on the dial 92 the number of plates which have been exposed in the change
Each of the.
box and will also shew the number of unexposed plates therein.
sheaths A to A12 has a small projection a² at its upper edge of a size to rest
against the teeth I or J of the disc F and also to pass through the notches I
and M between the said teeth.
The working of the mechanism above described is as follows:-The change box
having been charged with say for instance 12 plates in corresponding sheaths, the
finger H, by which the disc F is turned, is set to indicate " 1 as shewn in Fig. 4,.
and the said pin a² at the top of this sheath will pass through one of the notches L.
between the larger circle of teeth I and rest against one of the teeth J in the
smaller circle. The parts are thus shewn in Fig. 6, the first plate A¹ being now
in position to be exposed. After this plate in the sheath A¹ has been exposed,.
the finger H is turned through a small angle thereby correspondingly turning the
dise F so that the projection a² on the top edge of the sheath A¹ of the front or-
exposed plate will now pass through one of the notches M between two of the
teeth J of the smaller circle, as shewn in Figs. 1 and 7, and the sheath A¹ with its
plate will then fall down to the bottom of the camera turning on its bottom side.
pins a' as centres, the forward fall of the plate being broken by the usual light
spring frame N (see Fig. 1) hinged near the top of the camera which is pressed
forward by the plate A in falling and then springs upwardly again ready for the
next plate. The construction of this spring plate N is well known. The turning
of the disc F as aforesaid to release the plate A¹ as aforesaid simultaneously
brings one of the teeth I of the larger circle in position for the projection a² on the
top edge of the second sheath A² to rest upon, as shewn in Fig. 7, until the first.
sheath A has fallen and then the continued movement of the dise F, until the
finger H indicates "2," allows of the projection a² on the top of the second sheath A³
passing through one of the notches L between the larger circle of teeth, so as to
rest against one of the teeth J of the smaller circle and thus bring the second plate
in the sheath A2 in position and ready for exposure. Then when this plate in the
sheath A2 has been exposed the movement of the finger H towards "3" on the
dial will bring one of the notches M in position for the projection a² of the sheath A2
to pass through and fall as shewn in Fig. 8. Thus by turning the finger H on the
outside of the camera the exposed plates are successively allowed to fall down out.
of position and a new plate is moved in place to be exposed, the finger H indicating
on the dial the number of plates which have been exposed and by subtracting
these from the number of plates which were placed in the camera the number of
unexposed plates is arrived at.
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 the change box of a photographic camera in which the sheaths containing

page_text: the plates are pressed forward by a spring and suitably guided in position, the
employment of a disc in the inside of the top of the change box made with two
concentric circles of alternate teeth and spaces, said disc being so arranged in
combination with a projection on the top of each of the sheaths, that when the
disc is turned a plate will thereby be held in position for exposure and after the
exposure will be released and fall to or towards the bottom of the camera out of
the way of the next unexposed plate which will be similarly held in position for
exposure, substantially as herein before described.
2. In the change box of a photographic camera fitted with a disc made with
two sets of concentric teeth as and for the purpose denoted under the first claiming
clause hereof, the combination with said toothed disc of an index finger for turning
the same and a numbered dial which indicates the number of exposed and
unexposed plates in the camera, substantially as described.
3. In the change box of a photographic camera fitted with a disc made with two
sets of concentric teeth as and for the purpose denoted under the first claiming
clause hereof, the combination with said toothed disc of the side guides B B fixed
to the sides of the change box for the sheaths to rest on said guides being made with
stops b' substantially as and for the purpose set forth.
Dated this 2nd day of December 1895.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.