Improvements in and connected with Swing Backs for Photographic Cameras.
Year: 1894

page_text: Date of Application, 11th Dec., 1894
Complete Specification Left, 11th Feb., 1895-Accepted, 16th Mar., 1895
PROVISIONAL SPECIFICATION.
Improvements in and connected with Swing Backs for Photographic
Cameras.
I, HORACE HANDLEY O'FARRELL of Her Majesty's Indian Civil Service
Messrs. Coutts & Co., Bankers 59 Strand London do hereby declare the nature
of this invention to be as follows :—
My invention applies to the modern form of photographic camera in which the
back carrying the focussing screen folds down upon the base board. In this
type of camera the back is usually hinged to the base-board by its lower extremity,
thereby necessitating refocussing every time that the position of the back is altered
in regard to its motion in a vertical plane. In the older form of camera the swing-
back was pivotted in the centre, thereby ensuring that the centre line of the
picture on the ground glass was always in focus, however much the back might be
swung from the vertical position.
In order to obtain this advantage in the modern form of camera I abolish the
hinge, which usually connects the lower extremity of the camera back with the
base board, and allow the back to slide freely up and down the slots of the struts
which are used to connect the base board with the camera back, for this purpose
pivotting the back by its centre to short prolongations of the clamping screws
which are usually employed to clamp the camera back. These prolongations are
without any screw-thread and it will therefore be seen that when the clamping
screws are clamped at any point of the slots the camera-back is free to move, like
an ordinary looking glass, round its centre line as axis, but cannot move up or down
the slots. It is intended, however, that these screws shall only be clamped at the
topmost extremity of the slot of the struts. I provide the struts with pins or
stops, one to each strut, so placed as to limit the backward motion of the strut, &
allow it to rest at a convenient angle with the base-board, usually of about 45°.
These pins or stops may be attached to the struts themselves, or they may be
attached to the base board, or where the camera is provided with a side swing, to
some portion of the side-swing, in order to effect the object above indicated viz. to
limit the backward motion of the aforesaid struts. Thus when the camera is open,
and the clamping screws are clamped at the furthest extremity of the slots of the
struts, the camera back is free to move in a vertical plane round an imaginary
centre line as axis, in exactly the same manner as an ordinary swinging looking
glass.
It is, however, necessary to clamp or fix this back, so swinging, in any desired
position. For this purpose I usually employ two shorter struts, with clamping
screws, connecting the base board (or, if a side swing is used, the sliding bar of
the side swing) with the camera back, the end which is attached to the camera-
back moving in slots. These short struts, when the camera is closed, fold parallel
with the other pair of struts. To open the camera, all the clamping screws are
loosened, and the camera-back is grasped by the top and pulled upwards as far as
it will go.
The clamping screws attached to the longer or principal pair of struts
are then clamped, and these struts allowed to fall back till they are stopped by the
pins, and rest at an angle of about 45° or any other convenient angle with the base-
board. The back can then be swung, like a looking glass, to any required position
in a vertical plane about its centre line, and fixed in that position by clamping the
screws attached to the shorter pair of struts.
Instead of clamping the camera-back by the clamping screws attached to, or

page_text: sliding in the slots of, the longer pair of struts, I can also use as alternatives
spring catches, or bolts, allowing the camera-back to slide upwards till its centre
has reached the extremities of the slots, but holding it in position after it has
reached such extremities. Or the struts, or the slots thereof, may be curved at
their upper extremities, so that they may be approximately horizontal, when the
strut is stopped by the pins, and rests at an angle of 45° or other predetermined
convenient angle with the base-board, the pivots of the camera-back simply falling
into notches in the slots.
Dated this Eleventh day of December 1894.
Improvements in and connected with Swing Backs for Photographic
Cameras:
I, HORACE HANDLEY O'FARRELL of Her Majesty's Indian Civil Service
% Messrs. Coutts & Co., 59 Strand, London, 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 the modern form of photographic camera in which the
camera back folds down on the baseboard, and is designed to furnish such cameras
with an improved means of swinging the said camera back about its centre line.
The means whereby I effect this object is shown in the accompanying drawings.
In Figure 1,, A. B. C. represents one side of the camera back; seen in profile, and
E is the sliding bar of the "side swing" (if the camera is provided with such
swing). The back is loosely pivotted to an inner prolongation of the pin e in the
manner shown in Figure 2 which is a vertical section through the point e.
The pin e slides in the slot b of the strut FG. The slot may be straight or,
preferably, bent as in the diagram. The strut F G is prevented when the camera
is open from falling back by a pin shown as a (Figure 1) which keeps it at an
angle of 15° or other convenient angle with the baseboard. When the camera is
open, as shown in Figure 1, the pin e may be clamped tightly by a screwhead
(omitted in Figure 1 for the sake of clearness but shown in Figure 2 as k), and
the camera back will be still free to move round the pin e on a horizontal axis as
shown by the dotted lines in Figure 1. In order to fix it rigidly in any required
position I preferably use a short strut cf pivotted at c on the sliding bar of the
side swing, and having a pin sliding in a slot d in the camera back.
The pin is provided with a clamping screw similar to that attached to the pin e
and also omitted in the figure for the sake of clearness. 1 do not, however, claim
this method of rigidly fixing the back of the short strut cf as any part of my
invention.
I have hitherto spoken of the struts F G and ef as pivotted to the sliding bar
of the side swing. If the camera is not provided with a side swing, they are to
be pivotted directly to the baseboard.
The pin a may be attached to the strut F G on its inner side as shown in
Figure 1. Or it may be fixed to the sliding bar of the side swing (or if there be
no side swing, to the baseboard). In the latter case I prefer to adopt the
modification shown in Figure 3. The pin a drops into a socket formed of a
projecting portion of the strut F G, and is rigidly fixed by a clamping screw h.
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 camera in which the back folds down on the baseboard the

page_text: means of arresting the backward motion of the strut which connects the baseboard
for the sliding bar of the side swing) and the camera back by a pin or stop,
substantially as described.
2. In a photographic camera of the kind described, the method of loosely
pivotting the camera back on a centre pin, substantially as described.
3. In a photographic camera of the kind described, the combination of a camera
back loosely pivotted as claimed in 2, with the means of arresting the backward
motion of the strut connecting the baseboard (or the sliding bar of the side swing)
with the camera back by means of a pin or stop as claimed in 1.
Dated this Ninth day of February 1895.
H. H. O'FARRELL.