An Improved Time and Instantaneous Roller-blind Shutter for Photographic Purposes.
Year: 1898

page_text: Date of Application, 15th Mar., 1898
Complete Specification Left, 15th Dec., 1898-Accepted, 28th Jan., 1899
PROVIDIUNAL SPECIFICATION.
An Improved Time and Instantaneous Roller-blind Shutter for
Photographic Purposes.
CLARENCE JONES, 58, Ainsworth Street, Blackburn, in the County of Lancaster,
do hereby declare the nature of this invention to be as follows:-
I make the external case in the form of a wooden or metal box, there being two
rollers placed in parallel axes at either end, one having a motive spring, with a
milled head projecting from the side of the aforesaid box, for the purpose of
increasing or decreasing the tension.
The roller at the other end of the case serves to wind the blind, which is made
of macintosh or other suitable material. A metal spindle running through this
roller projects outside the case & in its extremity is fixed a small pin or lug. A
release lever having lateral & rising motion is provided at the side of the case,
and on it are certain projections. On the release lever being raised (the blind
having previously been wound on to the roller) the rotary motion of the metal
spindle causes the aforesaid pin or lug to come in contact with one of the projections
on the release lever. The impact of the pin on to the projection moves the
release lever a little to one side & in doing so brings into position a second projection
which is arranged to stop the rotary motion of the metal spindle on its second
revolution, and consequently the motion of the blind attached to it.
The removal of the upward pressure on the release lever allows the rest of the
blind to run down on to the bottom roller containing the motive spring. An
arrangement to alter the position of one of the projections on the release lever
provides for instantaneous exposures by allowing the blind to proceed from one roller
to the other without any intermediate stoppage.
Dated this 14th low of a 1900
An Improved Time and Instantaneous Roller-blind Shutter for
Photographic Purposes.
CLARENCE JONES, of 58, Ainsworth Street, Blackburn, in the County of Lancaster,
Scientific 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 ascer-
tained in and by the following statement:-
The object of this invention is to provide an improved photographic shutter, for
the purpose of shutting off all light from a sensitized plate or film, and to enable
the operator to allow any required amount of light to penetrate the photographic
Pine 8

page_text: ems, and so on to the sensitized plate at will, as I shall describe referring to the
accompanying drawings:
Figure 1 is a front view with one side of the case removed.
Figures 2 and 3 are end views shewing the parts in different positions.
I make the external case C in the form of a box, of wood, metal, ebonite, or other
suitable material, and in it are placed two rollers A and B in parallel axes, one at
either end.
The one marked A (hereinafter called the spring roller) contains a spiral spring,
the tension of which is increased by turning a ratchet placed outside the box.
The spring is prevented from running back by a pawl L engaging a tooth in
the axis of A.
The other roller marked B (hereinafter called the blind-roller) has one end of
its axis or spindle projecting outside the box.
To the rollers A and B are fastened the ends of a flexible blind (which I prefer to
make of macintosh cloth) which has a certain sized aperture in it, at about the
centre of its length.
On the blind roller I place a pulley, and attach to it a cord.
The tension of the spiral spring causes the blind to be normally coiled on the
spring roller, but by pulling the cord the blind is wound from the spring roller A
on to the blind roller B.
On releasing the cord the blind is again wound on to the spring roller, and the
passage from one roller to the other, causes the aperture in the blind to pass
certain openings in the sides of the box.
When the shutter is placed either before or behind a photographic lens, and in
front of a sensitized plate, the effect of these operations is to allow the passage of
light through the lens and so on to the sensitized plate.
The amount of light permitted to pass being regulated by the tension put on the
spiral spring, causing the blind to rewind more or less rapidly.
As it is sometimes necessary to give a longer exposure than is possible by the
motion above detailed, means are provided whereby when the blind has been wound
on to the blind roller, the cord may be released and the blind still remain partially
wound on to the blind roller, and with its aperture in line with the lens.
A release lever F, having lateral and rising motion is fitted to the side of the
box, and on the under side of it is a projection G.
The projecting end of the blind roller spindle has fitted into it, and at right angles
to it, a pin H.
The projection G on the release lever is in such a position, that when the cord
has been pulled the pin H is caught and held by it; the cord may then be released.
The shutter is then termed set.
The exposure is made by raising the release lever F, which causes the projec-
tion G to disengage from the pin H, thus allowing the blind to become wound on
to the spring-roller.
It is obviously impossible to decrease the tension of the spiral spring in the
spring roller sufficiently to give a longer exposure than a fraction of a second, and,
as a much longer exposure may be required it is necessary to provide means for
stopping the movement of the blind when the aperture is in line with the lens,
so that any required length of exposure may be given.
It is not convenient to hold the cord until a longer exposure is given, so means
are provided whereby, when the blind has been wound on to the blind roller, the
cord may he released, and the blind still remain partially wound on to the blind
roller, with its aperture in line with the lens.
To do this there are two shaped lugs or arms I and J fitted to the under side of
the release lever.
When the cord has been pulled and the shutter set, the cord may be released,
the pin H being held by the projection G.
Time or prolonged exposures are given as follows
The release lever is raised, and the projection G releases the pin H.

page_text: The blind roller then commences to revolve, and the blind to wind on to the
spring roller.
By the raising of the release lever, the lug I is brought into the track of the
pin H, with the result that the impact of the pin H against the lug I moves
the release lever in a lateral direction, bringing the lug J into the track of
the pin H.
On the pin H coming in contact with, and engaging with the lug J, the revolution
of the blind roller is stopped, the release lever being arranged not to move any
further in a lateral direction.
The stopping of the rotary motion of the blind roller prevents the blind winding
further on to the spring roller, the stoppage taking place after about one and three
quarters revolutions of the blind roller.."
The engagement of the pin H on to the lug J is arranged to take place when the
aperture in the blind is in line with the lens.
When sufficient exposure has been given, the release lever F is released, where-
upon the blind is entirely rewound on to the spring roller.
It is necessary to provide means for allowing the blind to run without stoppage
from the blind roller on to the spring roller, after the release lever has been
raised.
This is effected by making the lug I movable.
The lug I is cranked and extended to the upper side of the release lever and is
pivoted at the screw K.
When, therefore, the upper extension of the lug I is moved to the right of the
release lever, as in Fig. 2, the lug I is in such a position that on the release lever
being raised, the pin H will come in contact with it, and thus give a time exposure
as described.
If, however, the upper extension of the lug I be moved to the left of the release
lever, as in Fig. 3, the lug I will not be in the track of the pin H, on the release
lever being raised; the blind will therefore rewind on to the spring roller without
stoppage.
A small projection on the outer edge of the extremity of the blind roller spindle
coming in contact with the under side of the release lever, brings the release lever
back to its original position, on the shutter being set.
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:
In combination with the spindle of the blind roller of a photographic shutter,
a release lever having lateral and rising motion, and having fitted to it one fast
and one movable arm, and a projection, arranged to engage with a pin fitted in the
axis or spindle as described, and for the purpose as set forth.
Dated this 14th day of December 1898.