Improvements in Photographic Cameras.
Year: 1895

page_text: Date of Application, 21st May, 1895-Accepted, 22nd June, 1895
Improvements in Photographic Cameras.
I, FRIEDRICH HAARSTICK, Photographer, of 34 Bolkerstrasse, Düsseldorf, in
the German Empire, 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 relates to that class of photographic cameras, which in addition to
the ordinary camera adapted to receive the sensitised plate or film contains also an
auxiliary or focussing camera.
Hitherto it has been usual, to connect the auxiliary camera rigidly with the
principal camera, and the design was not, therefore, suitable for variable
distances.
To avoid this defect, I connect the two cameras by a hinge or other joint which
allows one camera to be turned relatively to the other and provide a suitable
device for securing them in the desired position.
In further describing the invention, reference will be made to the accompanying
drawings, of which
Fig. 1 is a plan of a compound camera embodying my invention,
Fig. 2 shows the same in a different position,
Fig. 3 is a sectional elevation along line A-B of Fig. 1,
Fig. 4 is a sectional back-view along line C-D of Fig. 1,
Fig. 5 is a section of the base plate along line E-F of Fig. 1,
Fig. 6 a section of the base plate along line G-H of Fig. 1,
Fig. 7 represents a device for varying the angle between the two cameras.
In the type illustrated by Figs. 1 and 2, the main-camera and the auxiliary
camera are mounted on separate plates pivoted on a vertical hinge pins situated
near the front ends of the camera and between the same. The desired angular
adjustment may be produced by means of a spindle with right and left hand screw
thread and a button s', as shown by Fig. 7, said spindle passing through a pair of
screw nuts pivoted to a pair of lugs at the rear ends of the cameras.
The rear end of the main camera is adapted to receive the slide containing the
sensitised plate or film, while the auxiliary camera has at its rear end a ground
glass plate, and when in use, both cameras are directed on the same object. When
the two cameras are in the desired position, and the sensitised plate or film has
been inserted, the operator watches the image on the ground glass plate of the
auxiliary camera, and when he is satisfied as regards the clearness and general
appearance of the image, he acts on the instantaneous shutter or draws the slide, so
as to expose the sensitised surface of the main camera.
My invention is applicable also to stereoscopic cameras, in which case the
auxiliary camera is preferably mounted above the two main cameras.
In the design represented by Figs. 1 and 2, the angle between the optical axes
of the two cameras is varied automatically by adjusting the cameras for various
distances.
For this purpose, the hinge pin or pivot s connecting the two base plates p p is
mounted on a toothed rack 2 which is guided in a straight line by a stationary
bearings and into which gears at the rear end a pinion t. The two cameras,
rendered extensible in the usual manner by means of flexible bags or other suitable
means, are fixed in front to the base plates p, while the rear end of each camera is
adapted to slide on its plate, being guided by a pair of flanges or ledges p¹µl

page_text: parallel to the optical axis, and also by a stud o fitting into a slot 1 of the base
plate p.
In order, that the rear part of the camera may retain its position, while the
plates p, p together with the front of the camera, are being drawn forward and
backward, the bolts o extend through transverse slots o³ of the main frame or
base which supports both cameras, said slots permitting only a lateral motion.
If the plates p are drawn back, they impart this motion to the camera fronts fixed
on the same, but not to the rear ends of the cameras, which are retained by the
studs o extending through the cross slots o¹ of the main frame g.
To provide, that the plates p, p, will move apart at the back, when they are
being drawn forward, and that they will approach each other at the back, when
they are drawn backward, the main frame has inclined slots a', in which are
guided the pins a fixed to the plates p, p.
If the plates p, p are withdrawn, so as to reduce the length of the cameras as far
as possible, which position is represented by Fig. 1, the optical axes of the two
cameras are almost parallel, but in the position represented by Fig. 2, where the
plates pp together with the camera fronts have been drawn forward as far as
possible, the optical axes of the two cameras form a considerable angle.
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 a photographic duplex camera, the combination of a main camera, with an
auxiliary or focussing camera, and means for turning the said cameras, so as to
vary the angle between their optical axes, substantially as and for the purpose
described.
2. In a photographic duplex camera, the combination of the main camera, with
an auxiliary or focussing camera, a rectilinearly guided hinge joint connecting the
front ends of the base plates p, and slots and pins a, a¹ or equivalent transverse
guides for the rear parts of the base plates, substantially as described.
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3. In a duplex camera of the type described above, a pair of pins and slots 0,
or equivalent guides which permit only a transverse motion of the cameras,
substantially as described.
Dated this 20th day of May 1895.