Improvements in Shutters for Photographic Cameras.
Year: 1892

page_text: Date of Application, 2nd Mar., 1892
Complete Specification Left, 2nd Dec., 1892-Accepted, 7th Jan., 1893
PROVISIONAL SPECIFICATION.
Improvements in Shutters for Photographic Cameras.
I, EDWARD HOWARD PERCY HUMPHREYS of 8 Hyde Park Gate, London,
Gentleman, do hereby declare the nature of this invention to be as follows:-
My invention has reference to shutters for photographic cameras and it consists
in forming such shutters of a tube having two openings or apertures diametrically
opposite each other or of a solid rod or bar having an opening or aperture formed
through the same at right angles to the axis. The tube or rod is free to be turned
on its axis and is provided with a spring which when set tends to give it a partial
rotation, a catch retains it in the set position. The tube or rod is so placed with
respect to the lenses that when the opening or openings above described are in line
with or face the lenses the beams or pencils of light pass through them.
The focus of the object to be photographed is taken when the opening or openings
are in a line with the lenses. The tube is then turned partly round until it engages
with the catch, and in this turning movement the spring is set and the openings in
the tube are moved out of line with the lenses a dark or full portion being pre-
sented to them. When it is required to make an exposure the catch is released;
the spring then causes the tube to partially rotate and in this movement the openings
come temporarily in line with the lenses so that the photograph is taken.
Instead of a single tube or rod I can and preferably do employ an inner tube or
rod and an outer tube having openings corresponding with those in the inner tube
or rod, and in this case either the outer or the inner tube or both the outer and
the inner tubes can be arranged to rotate. Or instead of or in addition to a rotary
motion either of the tubes may be free to be moved longitudinally.
In some cases I fit one or both of the lenses in the opening or openings of one or
other of the tubes.
My shutters can be employed as either instantaneous or time shutters; when
they are used as time shutters I provide for retarding the movement of the shutter
under the action of the spring, so as to produce more or less retardation as may be
required. This may be effected by more or less winding up the spring, an indicator
or scale being used to show the various degrees of retardation; or the desired
object can be obtained by means of a brake or similar device. Or I employ two
catches one of which holds the shutter in the dark position and the other in the
light position. Then when a time exposure is required the shutter would be moved
to the catch that holds it in the light position and would be released by the operator
when the necessary time had elapsed.
Dated this 2nd day of March 1892.
J. C. MEWBURN,
55 and 56, Chancery Lane, London, Chartered Patent Agent.
No text detected.

page_text: in forming such shutters of a tube having two openings or apertures diametrically
opposite each other. The tube is free to be turned on its axis and is provided with
a spring which when set tends to give it a partial rotation; a catch retains it in
the set position. The tube is so placed with respect to the lenses that when the
openings above described are in line with or face the lenses the beams or pencils of
light pass through them.
The focus of the object to be photographed is taken when the openings are in
line with the lenses. The tube is then turned partly round until the openings in
same are moved out of line with the lenses, a dark or full portion being presented
to them When it is required to make an exposure, the spring having already
been wound up or set, the catch is released; the spring then causes the tube to
partially rotate and in this movement the openings come temporarily in line with
the lenses so that the photograph is taken.
Instead of a single tube I can and preferably do employ in conjunction with an
inner tube an outer tube having openings corresponding with those in the inner
tube, and in this case either the outer or the inner tube or both the outer and the
inner tubes can be arranged to rotate.
In some cases I fit one or both of the lenses in the opening or openings of one
or other of the tubes.
My shutters can be employed either as instantaneous or time shutters; when
they are used as time shutters I provide for retarding the movement of the shutter
under the action of the spring so as to produce more or less retardation as may be
required. This may be effected by more or less winding up the spring, an indicator
or scale being used to show the various degrees of retardation; or the desired
object can be obtained by means of a brake or similar device. Or I employ two
catches one of which holds the shutter in the dark position and the other in the
light position. Then when a time exposure is required the shutter would be moved
to the catch that holds it in the light position and would be released by the operator
when the necessary time had elapsed."
The accompanying drawings illustrate two modifications or ways of carrying out
my invention. Referring first to Figures 1 to 6 wbich represent the preferred
modification,
Figure 1 is a transverse section of the lens tube of a camera with my invention
applied thereto;
Figure 2 is a section on the line 2-2 of Figure 1 looking in the direction of the
arrow;
Figure 3 a section on the line 3—3 of Figure 1 looking in the direction of the
arrow;
Figure 4a section on the line 4-4 of Figure 1 looking in the direction of
the arrow;
Figure 5 a section the same as Figure 4 but showing the stops or catches in
another position; and
Figure 6 an end view of the lens tube without the lenses.
The shutter is shown as situated between the lenses, but it may be either behind
or in front of them.
In these figures a is the lens tube. Across this tube is fixed a tube b having an
opening cat each side of same in line with the lenses. Within the tube is
another tubed hereinafter called the rotating tube which has likewise an opening e
at each side; according to the position for the time being of the rotating tube the
openings e are either in line with the lenses and with the openings c in the tube b so
as to allow the beams or pencils of light to pass, or as seen in Figure 1 they are
not in line with the lenses so that the beams or pencils of light cannot pass.
Across the lens tube are fixed three screens X X and Y. The parts composing
the catch and the brake hereinafter described are preferably attached to the middle
screen Y. To the rotating tube d is fixed one end of a spring f the other end of
which is attached to the arbor of a finger piece by which this arbor can be
rotated so as to wind up and set the spring, the rotating tube during the winding

page_text: operation being held as hereinafter explained. Fixed to the arbor is a ratchet
wheel i into which a spring pawlj takes so as to prevent return movement of the
arbor and finger picce. The rotating tube d has its bearings at the one end in the
arbor which is formed hollow for the purpose and at the other end in a fixed
piece or block k. A disc fixed to the end of the rotating tube carries four stop
pins or studs m m¹ and n n', the pins m m' being at a greater distance from the
centre than the pins n n'; co-operating with these stop pins is a catch piece p
which by means of a head p' can be moved in and out between guides rr formed
with passage ways s s'; the inner end of the catch piece bears against a spring t,
and it carries three stop catches u, u and u². The normal or set position of the
catch piece p is seen in Figure 4; in this position one of the pins m bears against
the stop u, and assuming that the spring has been wound up or set retains the
rotating tube d in the dark position. Then if it is required to take an instantaneous
picture (the focus having previously been taken) the piece p is pushed inwards by
means of the head thus forcing the spring t into the position seen in dotted lines
in Figure 4. This movement shifts the stop u clear of the pin m so that the tube a
can rotate under the force of the spring, the pin m passing through the passage s
and the pin n through the passages. As the stop shifts clear of the pin m to
allow the latter to pass, the stop u² comes into position in a line with where the
stop u was and thus stops the pin m² when it comes round. Thus the tube can
never make more than half a revolution at a time. When on the other hand it is
required to take a focus or to take a time photograph the catch piece p is lifted
to the position seen in Figure 5, the stop u being then clear of the outer pins m
and the stop u being in position to catch or stop one of the inner pins n n' at the
open position of the rotating tube, where in the case of taking a time photograph
it can remain as long as the operator thinks necessary. In taking a so-called
instantaneous photograph the length of the exposure can be regulated by a
suitable brake. I show by way of example a brake in the form of a piece v which
can be pressed against the circumference of the rotating tube d by means of the
set screw w, the degree to which this is screwed up increasing or diminishing the
brake pressure and therefore the length of the exposure as desired. The piece v
is normally kept pressed away from the rotating tube by the spring v.
Referring now to the modification shown in Figures 7, 8 and 9, Figure 7 is a
transverse section of the lens tube, Figure 8 a section on the line 8-8 of Figure 7
looking in the direction of the arrow and Figure 9 a section on the line 9-9 of
Figure 7 looking in the direction of the arrow. In this modification there are in
the head of the rotating tube d three stop pins m¹ m² m³ co-operating with a spring
catchic.
As the spring is wound up by means of the finger piece the tube d
turns with this piece. When it has received a quarter turn the pin m³ engages
with the catch a which had temporarily moved back to let the pin pass and the
tube is now in the open position allowing the focus to be taken; then another
quarter turn brings the pin m³ into engagement with the catch x, the tube being
now in the closed position and the spring set or wound; the pin m³ by coming
against the fixed stop z has prevented the tube being rotated too far. Then when
it is required to take a photograph the catch is released by pushing in the
plunger z which acts on the tail of the catch. The tube d then at once makes a
half rotation until the pin m³ comes against the other side of the stop z during
which movement the openings of the tube dare temporarily in line with the lenses
so as to give the required exposure. The form of brake I show in this modifica-
tion for regulating the length of the exposure (but I may use any other suitable
brake such for example as that shown in Figures 1 to 6) consists of a friction
wheel bearing against the disc at the end of the rotating tube. This wheel v
is adjustable along its spindle by means of a finger v¹ which can be worked from
the outside of the lens tube a. According to the greater or less distance of the
wheel from the centre of the disc so will the friction between the said wheel
and disc be greater or less. v² is a fan on the spindle of the wheel v.
υ

page_text: 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 :-
1. A shutter for photographic cameras consisting of a tube having two openings
diametrically opposite each other and capable of being turned on its axis so as to
move the said openings at one time into line with the lenses and at another time out
of line with the lenses, and the tube being fitted with a spring for giving the
required turning movement at the time of taking a photograph all substantially as
herein before described.
2. The combination with a tube such as referred to in Claim 1, of an outer
tube having openings corresponding with those in the inner tube, either the inner
tube or the outer tube or both being capable of rotation, substantially as and for
the purpose herein before described.
3. Constructing shutters for photographic cameras substantially as hereinbefore
described and shown in Figures 1 to 6.
4. Constructing shutters for photographic cameras substantially as hereinbefore
described and shown in Figures 7, 8, and 9.
Dated thin and 1...
1000
J. C. MEWBURN,
55 and 56, Chancery Lane, London, Chartered Patent Agent.