Improvements in Shutters for Photographic Lenses.
Year: 1893

page_text: Date of Application, 23rd Feb., 1893
Complete Specification Left, 23rd Nov., 1893—Accepted, 23rd Dec., 1893
PROVISIONAL SPECIFICATION.
Improvements in Shutters for Photographic Lenses.
I, Fox SHEW of 87 Newman Street, Oxford Street, in the County of Middlesex,
Photographic Instrument Maker, do hereby declare the nature of my invention to
be as follows:-
My invention relates to that class of shutters for photographic lenses, in which a
plate or disc provided with an aperture is adapted to revolve about a centre, so as
to allow the rays of light to pass through the lens at a certain portion of the
revolution; and has for its object the special construction and arrangement of such
a shutter, whereby a large diameter of opening is obtained, and at the same time
the shutter is compact in form, and can be attached to the camera as a complete
apparatus, so as not to occupy more room that the ordinary lens flange does; also
special means are provided for actuating and regulating the speed of the shutter;
and also the manufacture is much cheapened and simplified.
I carry out my invention by forming a shallow circular hollow casing, with which
I combine the flange for attachment to the camera front. This case can, if desired,
be sunk into the camera front. Upon the front face of this case, and eccentric
therewith, I attach the lens and provide an opening in the back and front of the
said case directly opposite the said lens.
Within the case I arrange a disc or plate, which can revolve about an axis in or
carried by the said case; this disc or plate is provided with the usual aperture,
which, passing by the aperture in the case, admits light through the lens to the
sensitive surface.
I drive this disc or plate by means of a spiral spring, which is attached to the
disc direct or through gearing, adapted to revolve the disc or plate by the satis-
faction of any tension in the said spring; the other end of the spring is arranged to
be coiled upon or uncoiled from a pulley cam or drum, arranged to revolve about a
centre in order to regulate the stress in the spring when the shutter is set ready for
action.
In order to extend the range of elasticity of the spring, I may lead the spring
around one or more pulleys, and thus get a longer spring into the limited space
available upon the case.
Means are provided for the adjustment of the spring tension device upon the
exterior of the case, such as by an index finger in connection with a scale or other
similar device.
A convenient form of mechanism for driving the disc by the spring is that of a
sliding rack or a rotating cog wheel, which can gear with a cog wheel attached to
the disc. A spiral spring is attached to the sliding rack or to a drum or pin on the
rotating cog wheel, so that on one or the other (as the case inay be) being actuated
by the spring, it will revolve the disc. Suitable engaging notches and a retaining
detent are provided on the shutters, to retain the shutter in the set position against
the spring pressure.
I may also arrange a safety shutter to co-act with the ordinary shutter plate, so
as to prevent the passage of light into the camera, when the operation of setting
the shutter, ready for exposure, is being performed.
This device may consist of a plate mounted on the same axis either in front of or
behind the shutter plate; this safety plate is provided with an engaging notch, and
is connected to the case by a spring, which is adapted to maintain it in a normal
position away from the lens aperture.
The shutter plate carries a spring detent, which, when the shutter is released and
flies back to its unset position, will engage with the said engaging notch on the

page_text: safety shutter, locking the two shutters together in such a relative position to one
another, that the aperture of the shutter is covered by the safety shutter, so that
on the shutter being set, in which action the aperture in the shutter moves across
the lens aperture, light is prevented from entering the camera by the intervention
of the safety shutter.
I may
apertures.
if desired fit a rotating stop plate upon the shutter having different sized
On the shutter plate arriving at the end of its movement, towards its set position,
the spring, detent engages with an inclined plane arranged on the case, which lifts
the detent out of engagement with the safety plate, thus allowing the latter to be
pulled back into its normal position by its spring.
It is obvious that this arrangement of the revolving disc shutter is very compact,
and occupies very little space, as it is screwed on to the camera front in place of the
ordinary lens flange.
Dated this 23rd day of February 1893.
FELL & WILDING,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Shutters for Photographic Lenses.
I, Fox SHEW, of 87 Newman Street, Oxford Street, in the County of
Middlesex, Photographic Instrument Maker, 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 that class of shutters for photographic lenses in which a
plate or disc provided with an aperture is adapted to revolve about a centre, so as
to allow the rays of light to pass through the lens at a certain portion of the
revolution of the shutter and has for its object the special arrangement and
construction of such a shutter, whereby a large diameter of opening is obtained
and at the same time the device is compact in form and can be attached to the
camera as a complete apparatus with the lens, so as not to occupy more than
the ordinary lens flange does; further special means are provided for actuating
the shutter and regulating its speed, and by its form the manufacture is much
cheapened and simplified.
In order that my invention may be the better understood I will now proceed to
describe the same in relation to the drawings hereunto annexed, reference being
bad to the letters and figures marked thereon. Like letters refer to like parts in
the various figures.
Figure 1 is a side elevation of one form of my shutter with the lens attached,
the flange for attachment to the camera being arranged on the back portion of the
shutter case.
Figure 2 is a front view of the same.
Figure 3 is a side elevation of the shutter and lens, with the flange arranged on
the front portion of the case, the latter being adapted to be recessed into the
camera front.
Figure 4 shows a front view of the shutter with the actuating mechanism shown.
Figure 5 shows a modification of the mechanism.
Figure 6 shows a shutter fitted with an automatic safety shutter.
Figures 7 and 8 shows two detail views of the retaining and trapping device of
the safety shutter.
Figure 9 shows a detail of the detent and releasing push shown in Figure 6.
Figure 10 shows revolving diaphragms in combination with the shutter.
Figure 11 is a sectional view of same.
Figure 12 shows the spring taken round a number of pulleys to allow of a longer
length being used.

page_text: I carry out my invention by forming a shallow circular hollow casing A with
which I combine the flange B for the attachment of the device to the camera front,
either direct as shown in Figure 1 or for being recessed in as shown in Figure 3.
Upon the front plate C of the case A and eccentric therewith I attach the lens D,
and provide an opening E in the back F and front C of the case A directly
opposite the lens D.. Within the case A. I arrange a disc or plate G which is
adapted to revolve about an axis H and has the usual aperture J, which aperture
by passing by the apertures E in the case admits light through the lens to the
sensitive surface in the camera.
I drive this disc or plate G by means of a spiral spring K which is attached to a
pulley L on the disc G direct as shown in Figures 4 and 12 or through gearing as
shown in Figures 5 and 6, adapted so as to revolve the disc G by the satisfaction
of any tension in the spring K. The other end of the spring K is attached to an
arm or drum M which is adapted to turn about its centre in order to regulate the
tension in the spring to provide for different speeds of the shutters. In order to
extend the range of elasticity of the spring I lead the spring around one or more
pulleys N as shown in Figures 4, 5, 6 and 12, and thus get a longer spring into the
limited space available within or upon the case. An index finger O is provided at
the exterior of the case A rigidly connected with or to the tension lever or drum M,
so that the adjustment of the tension may be definitely regulated; suitable marks
or letters being arranged on the face of the case to which the index finger can be
set for specific speeds.
It will be seen that the gear in Figure 5 for driving the disc is a sliding rack P
to which the spring is attached which is adapted to gear with a pinion Q fixedly
mounted on the shutter plate or disc G; a piu R carried by the sliding rack P
passes out through a slot r to the exterior of the case to enable the rack and
mechanism to be operated. In Figure 6 the driving mechanism consists of a
segmental cog wheel P' which is actuated by an external crank handle R', the
wheel gearing with the pinion Q of the dise, and having attached to it the spring K.
Suitable engaging notches S and a spring pressed retaining detent T of the forms
shown in Figures 4, 5, 6 and 9 are provided to retain the shutter in the set position
against the spring pressure.
In Figures 4 and 5 the detent T is adapted to move about an axis at right angles
to the face of the case A so as to engage in notches S in the shutter G while in
Figures 6 and 9 the axis of the detent T is parallel to the face of the case A and
is adapted to engage with projections or notches S on the face of the shutter
plate G.
In Figure 6 I show the shutter arranged with a safety shutter plate V which is
made to co-act with the disc or plate G, so as to prevent the passage of light into
the camera when the operation of setting the shutter ready for exposure is being
performed.
This safety arrangement consists of the plate V adapted to cover the aperture .J
in the disc G, and to be loosely journalled upon or about the axis of the shutter
plate or disc G. This plate V has a pulley V₁ attached to which is a spring W
for actuating the said plate V, the spring being attached to the case A and having
a tensional stress set up in it which always tends to bring the safety plate V back
to a stop or pin W' mounted upon the interior of the case A. The shutter plate
carries a spring mounted retaining catch X which is adapted to engage with a
projection Y on the safety shutter, in such a position that the safety plate.V covers
the aperture in the disc G. The catch X has at its end an inclined face X' which
during the partial revolution executed in setting the shutter (after the aperture J
has passed the aperture E in the case A) comes into contact with a projection or
pin on the case A, lifting the catch X from engagement with the projection Y
on the disc, and permitting the safety shutter V to be pulled back by its spring W
to its normal position, the main shutter disc G being retained by its detent T.
the main shutter G being released, it flies back to its unset position, and as it
reaches that position, the bevel edge Z of the catch X raises the edge of the
On

page_text: catch X over the projection Y, and engages the said catch X with the back edge
of the projection Y locking the shutters G and V together, ready for the next time
of setting of the shutter.
In Figures 10, and 11, I have shown a rotating stop plate a having different
sized apertures. This plate a is loosely journalled on the pin b and the shutter
disc G is journalled about the sleeve c attached to the plate a; on the back plate F
of the case four rounded recesses or depressions d are arranged, either one of which
can engage with a rounded projection e on the back of the diaphragm plate a
according to the particular orifice that is to be opposite the aperture E. A milled
head is provided on the sleeve c to actuate the stop plate a relatively to the
aperture E.
Having now particularly described and ascertained the nature of my. inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1st. A photographic lens shutter, consisting of a shallow case having means for
its attachment to a camera front, and on its front face means for attachment of the
lens eccentrically thereon, suitable apertures through the case for the admission of
light and a shutter adapted to be revolved within the case to allow the passage of
light through the shutter during its revolution, substantially as described.
2nd. In such a photographic shutter, a shutter plate adapted to be revolved by a
spiral spring, one end of which is fastened to a drum mounted upon or connected
by gearing to the said shutter and the other end of the said spring being connected
to an arm or drum adapted to be adjustable to increase or decrease the tension of
the said spring, substantially as described.
3rd. In such a photographic shutter the combination of a revolving shutter plate
having an exposing aperture in combination with a safety plate adapted to be
spring driven and detachably attached to the said shutter plate in the unset
position and to be carried by the said shutter plate over its aperture during the
operation of setting, and means for the release of the safety shutter from the
shutter plate when the latter has passed the aperture in the case during the operation
of setting the shutter, substantially as described.
4th. In such a photographic shutter as claimed in Claim 1, the shutter case in
combination with a disc having various sized apertures arranged to reduce the
working aperture of the lense, and means for moving and retaining the same
substantially as described herein and illustrated in Figures 10 and 11 of the
accompanying drawings.
5th. In a photographic shutter the combination of a spiral spring, with one or
more loose pulleys over which the spring is placed, so as to obtain a considerable
length of spring and consequent range of movement in a limited space, substantially
as described.
6th. The construction and arrangement of a photographic shutter, substantially
as described and illustrated in Figures 1, 2, 3 and 4 of the accompanying
drawing.
7th. The construction and arrangement of a photographic shutter, substantially
as described and illustrated in Figure 5 of the accompanying drawing.
8th. The construction and arrangement of a photographic shutter, substantially
as described and illustrated in Figures 6, 7, 8 and 9 of the accompanying
drawing.
Dad this 02nd dow of November 1802
FELL & WILDING,
1, Queen Victoria Street, London, E.C.; Agents for the Applicant.