An Improved Photographic Shutter.
Year: 1894

page_text: Date of Application, 11th Oct.,. 1894
Complete Specification Left, 11th. July, 1895-Accepted, 21st Sept., 1895
PROVISIONAL SPECIFICATION.
An Improved Photographic Shutter.
I, ALFRED CHARLES JACKSON of Crown Works, 98 Amhurst Road, Stoke
Newington, Optician do hereby declare the nature of this invention to be as
follows:-
The special feature of this invention consists in combining five distinct actions
OD A single plate, four of which are well known and one is novel.
The four known actions are as follows: (1) The safety ever-set shutter, (2) The
instantaneous time action, (3) Revolving stops or slides, and (4) A focussing tube
which slides on to the end of the lens tube or nozzle. These have not hitherto
been combined on one metal plate as I now propose to do, and I combine with them
two small brackets or angular strips projecting from the plate at right angles, to bo
used for steadying or fixing the plate when focussing.
To the foregoing I add the following novel action (5) which I have designed to
obtain and indicate to the operator, varying degrees of speed in the motion of the
shutter. On the outer side of the plate is a small cranked handle, connected to a
small spindle passing through the plate. At the back of the plate this spindle is
connected to another crank to the end of which the shutter spring is fastened.
The outer crank travels on a segmental scale on which Fast, Moderate, and Slow,
or other words are marked, and it carries on its extremity a small point which
engages with holes in the plate so as to hold it in any desired position. By
altering the cranked handle so as to stretch the spring tightly a higher speed can
be obtained in the action of the shutter..
100.0
SS.
BROMHEAD,
97 Newgate Street, London, Agent for Applicant.
ALFRED CHARLES JACKSON of Crown Works, 1984 Amburst Road Stoke
Newington, Optician, 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 is designed to afford greater facilities and convenience to the
operators of photographic cameras by combining five distinct actions on a
single plate, four of which are well known and one is novel; and all working
harmoniously together.
The four known actions are as follows: -(1) The safety ever-set shutter, (2) The
instantaneous and time action, (3) Revolving diaphragm or stops, and (1) A focussing
tube in which slides the lens body or lens tube. These have not hitherto been
combined on one metal plate, as I now propose to do, and I combine with them two
small brackets or angular strips projecting from the plate at right angles, to be
used' for steadying or fixing the plate when focussed.

page_text: !
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To the foregoing I add the following novel action (5) which I have designed to
obtain and indicate to the operator, varying degrees of speed in the motion of the
shutter. On the outer side of the plate is a small cranked handle, connected to a.
small spindle passing through the plate. At the back of the plate this spindle is
connected to another crank to the end of which the shutter spring is fastened.
The outer crank, travels on a. segmental scale on which figures 1, 2, 3 or words
representing "Slow," "Moderate and " Fast"
or other similar words can be
marked. The frout crank carries on its extremity, a small point which engages
with boles in a plate so as to hold it in any desired position.
By altering the cranked handle so as to stretch the spring tighter a higher speed
can be obtained in the action of the shutter.
A minor alteration is made also in the rotating diaphragm which carries the
working apertures.
Instead of placing the standard numbers for these apertures Dearly opposite the
openings, I place them between the apertures, and I stamp an arrow on the plate at
the point where the number should stop.
I will now describe the invention with reference to the accompanying drawings in
which :-
Fig. 1 shews a front view of the plate to which my improved shutter is attached,
with the front of my speed regulator.
Fig. 2 shews a back view of the said plate with the shutter and with the
mechanism in the open position for giving a time exposure, and a back view of my
speed regulator.
Fig. 3 shews a similar view to Fig. 2, but with the shutter mechanism in the
closed time position when set for time.
Fig. 4 shews a cross section of Fig. 3, on the line of the same fig. In this.
view (Fig. 4), the mechanism on the under side of the shutter is omitted to avoid
confusion.
The dotted lines indicate the focussing tube in which the lens body, e slides, thus
permitting a certain amount of side play for adjustment..
Fig. 5 shews an enlarged view of Fig. 4, with the mechanism on the under side, of
the shutter, and also shews the focussing tube e' in dotted liuca,
Fig. 6 shews an enlarged side view of the mechanism for releasing the exposing
shutter at the point of release.
Fig. 7 shews an enlarged portion of the special plaited tension spring.
a is the foundation plate of my shutter.
bb are angle pieces to keep the shutter steady or fixed.
c is the usual rotating diaphragm with graduated holes.
d' is a spring stop to keep the rotating diaphragm in place.
e is the lens body, which slides in the focussing tube e provided with horizontal
slots on each side of the shutter plate a eis the focussing tube fixed to a
partition inside the cainera in which the lens body e slides.
.
is a small crank mounted upon a. rotating, pin, and's serving; to tighten or
slacken the tension spring a mounted upon the outer end of another crank
opposite side of the shutter. This second crank f rotates with pin..
.
.9
is a tension spring fastened to the tail of the exposing shutter h..
on the
his the exposing shutter mounted upon and revolving around the screw i. The
outer end of this shutter passes through the horizontal slot in the leus body e,
and is further provided with the rectangular opening, as shewn in dotted lines!
k is a stop pin' for the shutter h.
i.
I
Lis the safety, blind operated by the slotted lever fulcrummed at !!..
mis a small band spring, fastened at one end on to the upper side of the exposing
shutter h, and furnished at the other end on the under side with a small tooth m¹
which engages with a small projecting piece on the safety, blind l. Thus both
the shutters and can be both moved backwards simultaneously.
The exposing shutter h is released in its backward movement by the tooth m² being,

page_text: lifted out of gear with the projection by means of the lug n furnished with a:1.
oblique or sloping face, as shewn in Fig. 6.
To permit of the shutter being used for instantaneous exposure the screwe
stop kis screwed downwards in the special countersunk hole out of the way of the
shutter by means of which a further travel will be given to same, the stop o taking
the place of the stop k.
made.
The mode of operations is as follows:-The operator having focussed his object,
inserted the sensitive plate and replaced the shutter !, has only to apply a sharp
pressure to the lever, when the shutter is removed and the impression taken.
The shutter falls back automatically. The spring g is formed by coiling two.
tempered steel wires, twisted together so as to form a strand. I find a
l'a spring
in this way does not lose its elasticity so soon as one made of a single wire.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is:
An improved photographic shutter, consisting of the usual everset_shutter,.
instantaneous and time action, revolving stops and lens body fitted with a focussing
tube; together with angular strips bb, speed regulator ff", and special'spring gas.
herein described and set forth.
Dated Guns Ich day of o
S. S. BROMHEAD,
97 Newgate Street, London, Patent Agent..
S. S. BROMHEAD,
97 Newgate Street, London, Patent Agent..