Improvements in and connected with Cinematographs.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in and connected with Cinematographs.
EDWARD HOLMES, 99, Culford Road, Kingsland, Photographic Apparatus Maker,
do hereby declare the nature of this invention to be as follows:-
:-
My invention is a shutter to be placed on the back of the animated photograph
projecting machine between the light and the film, to protect the film from fire.
It is driven by a band working from one of the driving wheels of the machine
so that it is entirely under the control of the operator. On the machine being
set in motion, the shutter immediately opens automatically, in an upward
direction. When the machine ceases working from any cause whatever: a very
slight reversal of the driving action causes the shutter to immediately close
downward; thus obviating all danger from fire. To effect this I place a bearing
on the back of the machine (in any suitable position), into which I insert a
spindle which carries a plate of aluminium or any other suitable material, on
the other end of the spindle is placed a small grooved wheel in which the band
of the aforesaid driving wheel runs.
Dated this 3rd day of November 1898.
Improvements in and connected with Cinematograpns.
I, EDWARD HOLMES, of 99, Culford Road, Kingsland, Photographic Apparatus
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 cinematograph machines and has for object to prevent
risk of fire (owing to the film becoming ignited through remaining stationary
in the focus of the illuminating rays) by providing a means whereby com-
munication between the film and the lamp or other source of light may be cut
off at will.
The invention, which is applicable to any class of cinematograph machine,
consists essentially of a shutter mounted to close the aperture in the framework
or body of the machine between the source of light and the film, said shutter
being so connected with the mechanism whereby motion is imparted to the film
as to be automatically held open so long as the mechanism continues in normal
working, and is capable of being closed virtually instantaneously by a very small
reverse movement of the driving mechanism, so as to be entirely under the
control of the operator.

page_text: Reference is to be had to the accompanying drawings forming part of this
specification wherein Figure 1 is a side view of so much as is necessary of a
cinematograph machine fitted with my invention, Figure 2 being a face view of
the same.
The shutter a consists of a plate of aluminium or other light and incombustible
material, pivoted or hinged at b to the back c of the cinematograph machine so
as to tend when free to drop down and close the aperture d through which the
beam of light is allowed to reach the film. The spindle f forming the pivot or
hinge pin for the shutter a has fixed to one end of it a small cord pulley 9 in the
pheripheral groove of which runs a band h which is also passed around the
periphery of another pulley i (preferably of larger diameter) fast on the spindle
of one or other of the driving wheels of the machine as may be most convenient.
The band is so arranged (either open or crossed as shewn) that whatever the
direction of rotation of the driving pulley i the forward movement of the latter
will cause the shutter a to be raised by an angular movement about its pivotal
support so as to uncover the aperture d. The shutter a is prevented from rising
further than is necessary by the engagement of an arm j fast on the shutter or
spindle with the frame c of the machine. The tension of the band his so
adjusted that so long as the machine is driven in the forward direction the band,
after raising the shutter to the extent permitted, slips around the periphery of
the pulley with such freedom as to offer no appreciable resistance to the
driving power although maintaining the shutter in the raised position. When
however, owing to any obstruction in working, the movement of the machine is
suddenly checked, the resulting slight recoil produced in the mechanism at once
causes a corresponding reverse movement of the pulley i, band h. and pulley
sufficient to instantly return the shutter a to the position closing the aperture d,
thus cutting off all communication between the source of light and the film.
It will be obvious that the greater the difference in diameter between pulleys g
and (the diameter of 9 being always the smaller) the more rapidly will the
shutter a be opened or closed with a given amount of motion of the driving
mechanism. The band his preferably formed by a closely wound helix of
spring steel wire as indicated, it being found that this affords the desired com-
bination of grip and slip essential to the proper working of the apparatus.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is
1. A safety appliance for a cinematograph machine adapted to prevent ignition
of the film by reason of its remaining stationary in the focus of the illuminating
rays, which consists in the combination with a shutter pivotally mounted on the
frame of the machine so as to tend to close the aperture through which the beam
of light reaches the film, of a pulley fixed on the spindle forming the pivotal
support of the shutter and a driving band in gear with said pulley and with a
pulley rotated by, or concurrently with, the driving mechanism of the machine
so that the shutter will remain open so long as the machine continues in normal
working and will be instantly closed when, owing to the movement of the
machine being suddenly obstructed, the direction of motion of the driving
mechanism is momentarily reversed, substantially as specified.
2. The safety appliance for cinematograph machines, constructed and operating
substantially as herein described and illustrated in the accompanying drawings.
Dated this 4th dor of Cantomha 1000
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.