instantaneous & time Photographic Camera Lens Shutter
Year: 1886

page_text: Date of Application, 27th Sept., 1886
Complete Left, 11th Jan., 1887.
Complete Accepted, 1st Mar., 1887.
JAMES SWIFT Optician, 81, Tottenham Court Road London W. do hereby declare
the nature of this invention to be as follows:-
--
An improved instantaneous & time Photographic Camera Lens Shutter, which
consists of two parellel slides working in same grooves & plane, made of any
suitable material. The edges of which meet, & slightly over lap each other in the
centre of the aperture of the Camera lens with which it is used. When in action the
lower segment is forced downwards by a spring, while the upper part of the shutter is
thrown in the opposite direction also by a spring, thus leaving the entire aperture of
the lens exposed to the action of the light. The same portion of the shutter when
forced up by the spring, returns by recoil & closes the aperture. The return of this part
closing the aperture can be made at the will of the operator from a fraction of a second
to any number of minutes. I further claim in my Invention the method of detaining
the upper segment of the shutter for time exposure before allowing it to close over the
aperture of the lens, this is effected by a loose hinged piece, which is made to shift
into position when required, so that the upper portion of the automatic piston arrange-
ment for discharging the shutter when put into action comes in contact with the
aforesaid hinged piece, which forces a tension spring on the upper segment of the
shutter & holds it in position until the pneumatic pump is relieved by the pressure of
the hand, when the piston rod descends & releases the tension on the segment of the
shutter; thus allowing it to fall over the aperture of the lens. I further claim, that
the two segments of the shutter can, when discharged be made to travel over the
aperture of the lens with only a partial opening between them. This contrivance is
necessary for very rapid exposures in bright atmosphere. What I claim is, the
application of the sliding shutters meeting over the aperture of the lens, only one
returning to shut off the light after exposure has been made, and also the upper
segment of the shutter can be retained in position for any length of time at the will of
the operator, after opening the shutter before it is allowed to descend to shut off light.
I further claim the mechanical arrangement of holding the upper segment of the
shutter until required to drop.
TAS CULT

page_text: JAMES SWIFT Optician, 81, Tottenham Court Rd. London W. 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 :-
.
An improved instantaneous & tine Photographic Camera lens shutter, which
consits of two parellel slides working in same grooves & plane, made of any suitable
material, the edges of which meet & slightly over lap each other in the centre of the
aperture of the Camera lens with which it is used. When in action the lower segment
is forced downwards by a spring, when the upper part of the shutter is thrown in the
opposite direction also by a spring, thus leaving the entire aperture of the lens exposed
to the action of the light. The same portion of the shutter when forced up by the
spring, returns by recoil & closes the aperture. The return of this part closing tho
aperture can be made at the will of the operator from a fraction of a second to any
number of minutes, and its velocity in returning can be increased by the action of a
spring against which it recoils. This spring being brought into play at the will of the
operator. I further claim in my invention the method of detaining the upper segment
of the shutter for time exposure before allowing it to close over the aperture of the
lens, this is effected by a loose hinged piece, which is made to shift into position when
required, so that the upper portion of the automatic piston arrangement for discharging
the shutter when put into action comes in contact with the aforesaid hinged piece
which forces a tension spring on the upper segment of the shutter & holds it in
position until the pneumatic pump is relieved by the pressure of the hand, when the
piston rod descends & releases the tension on the segment of the shutter, thus allowing
it to fall over the aperture of the lens.
I further claim that the two segments of the shutter can, when discharged be made
to travel over the aperture of the lens with only a partial opening between them, this
contrivance is necessary for very rapid exposures in bright atmosphere. Description
of Drawing. A. A. are two parellel slides, working in the same groove, the segments of
which when they meet over lap. B. B. are two pins which fit in the fork shaped piece (
for holding the parellel slides in position for action, the said fork piece is kept in this
position by the stem of the pneumatic piston D. E. is a pin under which the flexible cord
is placed, with the shutter thus arranged it is ready for exposure, when discharged b
the pnenimatic pump the lower segment is brought down by the action of the coile
spring F, & the upper segment of the shutter is thrown in the opposite direction & by
recoil returns & closes the aperture. The rapidity of this can be greatly increased
by the bow spring G, which can be brought into action by pressing downward. For
drop shutter & time exposures the two pins H. H, are brought into the fork piece &
when the shutter is discharged the lower segment falls, leaving the aperture open as

page_text: long as hand pressure is kept on the pneumatic pump, when the said pressure is
relieved the upper segment of the shutter descends & closes the aperture.
Having now particularly described the nature of my said invention, & in what
manner the same is to be performed, I declare that what I claim is:
The application of the sliding shutters meeting over the aperture of the lens, only
one returning to shut off the light after exposure has been made, & also the upper
segment of the shutter can be retained in position for any length of time at the will of
the operator, after opening the shutter before it is allowed to descend to shut off light.
I further claim the mechanical arrangement of holding the upper segment of the
shutter until required to drop.