Improvements in Shutters for Photographic Cameras.
Year: 1898

page_text: Date of Application, 14th Mar., 1898
Complete Specification Left, 7th Nov., 1898-Accepted, 17th Dec., 1898
PROVISIONAL SPECIFICATION.
Improvements in Shutters for Photographic Cameras.
I, PERCY WALLIS, of Queensbury Road, Kettering, in the County of North-
ampton, Manufacturer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to improvements in that class of shutter which can be
employed at will for either time or instantaneous exposures and is designed to
provide a shutter which while equally serviceable for the time or longer exposures
can be adjusted for the most rapid instantaneous exposures.
Hitherto the blind for these shutters has been made with a single opening
sufficiently large to expose the whole of the lens and the rapidity of exposure
has been dependent solely on the speed of the travel of the blind.
I now construct the blind with two apertures one of a width equal to the
diameter of lens and the other aperture in the form of a slit and so arrange the
winding and releasing mechanism that either aperture of the blind can be
brought into position to traverse across the plane of the lens.
The releasing mechanism I arrange with two or three sets of stops so that the
wide aperture may be employed for time or instantaneous exposures and the slit
for extra rapid exposures. For this purpose I insert an extra catch or stop in the
cog wheel of the releasing mechanism and a spring or other catch or stop to
engage therewith in addition to the catches or stops hitherto employed.
When the blind is used for time or short instantaneous exposures these catches
or stops do not come into use but may be used to prevent the blind being drawn
or wound up too far.
When, however, it is desired to draw or wind the blind up into position for the
rapid instantaneous exposure the catch is raised to allow the stop in the wheel
to pass and then when in operation the catch will act to prevent the blind return-
ing too far after the exposure has been made.
Dated this 10th day of March 1898.
Improvements in Shutters for Photographic Cameras.
I, PERCY WALLIS, of Queensbury Road, Kettering, in the County of North-
ampton, Manufacturer, do hereby declare the nature of this invention and in what
[Price 8d.]

page_text: the stops on the wheel E and also pivoted at g¹ to permit of the shoulder g being
moved into and out of the path of the stop as it rotates with the wheel E.
Below the end of the releasing lever G is an index plate H marked where the
arrow is placed with the word "time" and where the arrow h¹ is placed with
the word or abbreviation "inst." For instantaneous exposures the releasing
lever G is set with the arrow at the end opposite the arrow h¹ or word "inst."
on the index plate H and for time opposite the arrow h or word "time" thereon.
For rapid instantaneous exposure by means of the slit or aperture a¹ in the
blind A the blind is rolled up to its full extent on the roller B by means of the
knob D until the stop e on the wheel E engages the shoulder g of the releasing
lever G (see Fig. 8) thereby retaining the blind in position against the pull of
the spring roller C. The blind A and roller B are released on the raising of the
releasing lever G by the pneumatic ball F and the toothed wheel rotates the
support of the knob D carrying round with it the cranked or raised stop catch
or finger until the latter comes into contact with the shoulder of the releasing
lever G and stops the movement.
The catch finger d' is raised or cranked as shown to engage the shoulder g
when the releasing lever G is raised and to pass over it when not raised also to
ride over and prevent the raising of the lever G a second time immediately after
an exposure when in the position shown in Fig. 12.
For ordinary instantaneous exposures by means of the aperture a, the blind A
is rolled upon the roller B by means of the knob D until the stop e¹ engages the
shoulder of the releasing lever G (see Fig. 9) by which it is retained in position.
The blind is released as above described and checked by the finger engaging
the shoulder g of the lever G. For time exposure the blind is wound and set as
for ordinary instantaneous exposure but the position of the releasing lever is
altered to bring it nearer to the centre of the wheel E as in Fig. 10 when raised
by the pneumatic ball F. After releasing the blind the projection d on the under-
side of the knob I engages the projection or shoulder thereby checking the
travel of the blind (as in Fig. 11) until the releasing lever is lowered by the
deflation of the ball F when as before described the further travel is stopped by
the finger d against the shoulder 9 of the lever G as in Fig. 12.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. In shutters for photographic cameras a blind constructed with two apertures
one of a width equal to the diameter of the lens and the other in the form of a
slit and mechanism for operating either one or other as required whereby the
shutter may be variously employed for rapid instantaneous, ordinary instan-
taneous or time exposure substantially as described.
2. In shutters for photographic cameras the combination with a roller blind
provided with two apertures of different sizes of the rotating toothed wheel E
provided with stops e e the winding up knoh D the stop thereon and the loose
finger or catch to variously engage the shoulder g of the releasing lever G
substantially as and for the purpose described.
3. A shutter for photographic cameras having the several parts constructed
and arranged in combination substantially as and for the purposes described and
shown.
1000