An Improved Photographic "Detective" Camera and Changing Box.
Year: 1888

page_text: PROVISIONAL SPECIFICATION.
An Improved Photographic "Detective" Camera and Changing Box.
I THOMAS KERR of 52 Grosvenor Park Road Walthamstow in the county of
Essex, Trimming Manufacturer, do hereby declare the nature of this invention to be
as follows:
The sensitive plates are placed in the lower division of a changing box (which
consists of two chambers communicating) in separate cases of metal or other suitable
material, and pushed to the front vertically by a coil spring, and are thus exposed in
rotation. Each plate after exposure is raised to the upper chamber by means of a
vertical slide with catch at base the slide being worked by lever arms on a shaft from
the front of Camera-The plates on reaching the upper chamber are kept in position
by a second coil spring.
The plates are moved by the Operator from one chamber to the other by a lever
attached to the lever shaft which may be kept inside or brought outside the Camera
case (preferably inside) as desired, and fixed to this lever is a handle passed through a
slot in the side of Camera case. A lock is adjusted to secure the lever handle when
not in use.
.
For the purpose of registering the exposures a ratchet wheel, lever, and pawl is
attached to the lever arms on the side of Camera so that simultaneously with the
movement of each plate into position a numbered disc rotates, and shows the number
of exposures that have been made.
The object of the aforesaid improvements is to enable the operator to dispense with
opening the Camera when in use.

page_text: COMPLETE SPECIFICATION.
An Improved Photographic Detective Camera and Changing Box.
I THOMAS KERR,. of 52 Grosvenor. Park Road, Walthamstow in the County of
Essex, Trimming Manufacturer, do hereby declare the nature of my said invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:
The object of my invention is to effect improvements in the construction of
"detective" photographic cameras and changing boxes.
In carrying out my invention 1 provide two chambers at the back of the changing
box, one above the other. The lower chamber is provided with two doors at the back
end. The upper chamber is accessible from above. Each chamber is provided with a
spring to keep the plates in position. The exposure takes place upon the plates in the
lower chamber, each plate after exposure, being raised to the upper-chamber by
suitable means.
•
--And-in order that my said invention may be particularly described and ascertained
reference is hereby made to the accompanying drawings, in which-similar-letters_of_
reference indicate corresponding parts.
Fig. 1 is an external side elevation of the changing box.
Fig. 2 is a sectional elevation of the same with the slide in its lowest position.
Fig. 3 is a similar elevation showing a slide in the act of raising a plate.
Fig. 4 is a horizontal section.
a is the upper chamber. is the lower chamber. c c are the prepared plates, placed
in position ready for exposure, and d d are the plates raised to the upper chamber after
exposure. e is a partition between the two chambers. is an outer door hinged
at is a fastening to the door f consisting of a flat wire entering a bracket or
staple fixed to the door f. is an inner door, hinged at 9, and fastened by any
convenient form of catch. hh are sliding diaphragms fitting the chambers a and b,
and pressed forward by springs iik is a handle, the shank of which vibrates in the
curved slot. The handle is attached to the crank arm fixed to the axle m.
oo are two lever arms fixed to the axle m, and connected by means of connecting
rods with the slides t t. s is a solid partition to prevent the entrance of light
through the slot 7.
The slides t. and are made to slide against each other a certain distance. When
the slide is lowered down, as shown in Fig. 2 the catch sustains the forward
plate of the series c c the slide t' being suspended by catches resting against
the forward plate of the series d d, and keeping it in position for the ascent of the
next plate.
When the lever is raised, the slide t lifts up the front plate of the series cc
by means of catches t'as shown in Fig. 3, the slide being carried up at the
same time. When entirely raised, the plate takes its position in the series d d, and
the front plate of the series c c is left ready for exposure. p is an ordinary counting
apparatus actuated by the pin of attached to the lever o. A disc or other device is
attached to the wheel p having an opening in the case through which the number of
plates which have been exposed can be ascertained.

page_text: 24 15 the case containing the usual lens. □ is a movable partition which prevents the
light from reaching the plates d d.
By means of my improved apparatus the operator is enabled to dispense with opening
the camera when in use.
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 manufacture and use of the improved photographic detective camera
and changing box, provided with separate chambers a and b for containing the
plates, in combination with diaphragins hh, springs ii and the lifting appliances,
severally operating substantially as hereinbefore described and illustrated by the
drawings.
2. In combination with a photographic detective camera and changing box, the
application and use of the lifting apparatus consisting of the handlek, lever n, axle m,
lovers o o connecting rods »r, slides t t', and partitions substantially as hereinbefore
described and illustrated by the drawings.
3. The general construction, combination and arrangement of the several and
respective parts, together forming my invention of an improved photographic detective.
camera and changing box, substantially as hereinbefore described and illustrated by
the drawings.
Dal 1
001 1
T
GEO.
DOWNING,
8, Quality Court, London, W.C.,
Agent for Applicant.