Improvements in Slide Carriers and Apparatus for Optical or Magic Lanterns.
Year: 1894

page_text: Date of Application, 23rd Oct., 1894
Complete Specification Left, 23rd Mar., 1895-Accepted, 4th May, 1895
PROVISIONAL SPECIFICATION.
Improvements in Slide Carriers and Apparatus for Optical or
Magic Lanterns.
GEORGE DAVENPORT, 19, John Street, Adelphi, London, W.C., Clerk, do
hereby declare the nature of this invention to be as follows:-
This invention consists of a contrivance as described below, for producing on a
screen, by means of an optical lantern, the effect of a rising and falling curtain, in
combination with a panoramic or other carrier or slide frame for exhibiting and
changing lantern slides or transparencies.
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Any carrier or frame may be employed, but, by preference, I use a panoramic
or push through" form, about thirteen inches long, so that it will hold four
slides 3 x 31, at the same time.
In the lower part of the carrier or frame, under that portion which, when in
position in the lantern, is in front of the condenser, I insert, or let in, a roller
of metal or other material, running in bearings. On this roller is wound a blind
or curtain of silk or other material, of such dimensions that, when unwound, it
will cover over the space in the carrier or frame through which the light from
the condenser passes to the screen.
One end of this blind is fastened to the roller and the other end is attached
to a lath or strip of metal, or other material, which helps to keep the blind
stretched, and is provided with holes or other means for the attachment of the
cords by which the blind is moved. In the upper part of the frame or carrier is
cut a groove in which a rod or runner works. In the cover of this groove, at one
end, a slot is cut, and through this slot a stud or handle is fastened to the end of
the rod by means of which the rod is moved to and fro, but other means may be
employed for working the rod.
To this rod the ends of two cords of silk, wire, or other material are attached.
These cords pass through or over guides and are wound (one on each side) on the
roller carrying the blind. They then pass to the opposite side of the carrier and
are attached to or pass through holes or other contrivances in the lath or metal
strip of the blind, and are then carried up and fastened to the rod or runner
before mentioned, on the side opposite to that to which the other ends of the cords
are attached.
The action of the blind or curtain is as follows:-
When the rod is pushed along in one direction it draws the cords along with it.
These cords are fixed to the rod in such position that those on one side move away
from the blind when the rod is pushed along, while the cords on the other side
The cords in their
approach nearer to the blind during the same movement.
movement over the roller cause it to revolve and unwind the blind. The cords
by their attachment to the lath or metal strip of the blind carry the blind with
them as it unrolls, so that it covers the space in front of the condenser and
obscures the light, producing on the screen when focussed by the lantern lens,
the effect of a falling curtain. On withdrawing the rod or runner the movements
are reversed, the curtain falls, and is re-wound on its roller, producing on the
screen the effect of a rising curtain. In the interval between the falling and
rising of the curtain on the screen the slides or transparencies are changed or
pushed along by hand in the usual manner.
In place of the above rod or runner for moving the blind I employ, if

page_text: necessary, a rod, cylinder, or tube, revolving in the upper part of the carrier
or frame, to which the cords for moving the blind are attached or wound. Or
the blind roller itself may form part of a rod or tube which is revolved by a
handle or other contrivance, the cords being attached to the lath of the blind
and passing through guides or over a roller on the upper part of the carrier or
frame and back on the same or opposite side to the blind roller and the lath or
metal strip. Other means may also be used for actuating the blind.
The movement for producing the curtain effect, when attached to a slide
carrier, being independent of the movement for changing the slides, allows of the
carrier being used and the slides changed with or without the curtain effect as
desired.
The roller blind and the arrangements for actuating it may be fastened to a
frame separate from that carrying the slides, if desired, or may be attached to the
body or front of the lantern itself.
31
1
1004
Improvements in Slide Carriers and Apparatus for Optical or
Magic Lanterns.
GEORGE DAVENPORT, 19, John Street, Adelphi, London, W.C., Clerk, 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 :--
This invention consists of a contrivance as described below, for producing on a
screen, by means of an optical or magic lantern, the effect of a rising and falling
curtain; in combination with a "panoramic" or other carrier or slide frame for
exhibiting and changing lantern slides or transparencies.
Any carrier or frame may be employed, but, by preference, I use a "panoramic
or "push through" form, as shewn in drawing, of such size that it will hold four
slides, 3 x 3 inches square, at the same time.
In the lower part or base of the carrier or frame (see drawing), under that
portion which, when the carrier is in its proper position in the lantern, should be in
front of the condensing lens, I insert or let in a roller A, of metal or other material,
running in bearings B. B.
On this roller is wound a blind or curtain C, of silk, paper, or other material, of
such dimensions that, when unwound, it will cover over the space in the carrier or
frame through which the light from the condensing lens of the lantern is intended
to pass to the screen.
One end of the blind or curtain is fastened to the roller, and the other end i;
attached to a lath or strip D, of metal or other material, which helps to keep the
blind stretched. This lath is provided with holes or other means for the attachment
of the cords E, E, by which the blind is raised.
In the upper part of the frame or carrier is a groove F, in which a rod or
runner G, works or slides.
In the cover of this groove, at one end, a slot is cut, and through this slot a stud,
pin or handle, is fastened to the end of the rod or runner, by means of which the
rod is moved to and fro, but other means may be used for actuating the rod.
To this, rod or runner the ends of the three cords E, E, and H, are attached.
These cords pass through or over wheels or other contrivances acting as guides,
and the other ends of the cords E, E, are fastened to the lath or metal strip D, of
the blind, one on each side, as shewn in drawing, whilst the end of the cord H, is
fastened to the roller on which the blind is wound.

page_text: The cords E, E, and H, are fastened to the rod G, at such relative positions
r distances that, on pushing the rod along in one direction, the cords E, E, are
rawn along with it, and, by their attachment to the blind lath, pull, uncoil, and
aise the blind from its roller, so that it covers over the space in the carrier
hrough which the light from the condensing lens of the lantern should pass to the
creen.
The movement of the rod which causes the cords E, E, to be drawn along and
raise the blind, at the same time causes the cord H, to advance, and, by its attach-
ment to the blind roller, to become wound or coiled up on the roller as the blind is
unwound from it and raised by the cords E, E.
The rod, on
being withdrawn, pulls the cord H back with it, and causes it to unwind from the
blind roller.
On withdrawing the rod or runner the movements are reversed.
The unwinding of the cord H causes the blind roller to revolve and coil up the
blind upon it, the blind being kept taut by the cords E, E, which are drawn back
with the rod at the same rate as the cord H.
The cords E, E, and H, thus, so to speak, balance or compensate for each
others movements, and the blind will remain in any position according as the rod
or runner is moved backwards or forwards.
The working of the apparatus is as follows:-
The frame or carrier having been placed in the stage of the lantern in the usual
manner so that the space to be covered by the blind or curtain is in front of
the condensing lens-when the rod or runner G is pushed along in one direction,
the cords E, E, by their attachment to the rod, are drawn along with it, and, by
their attachment to the lath of the blind, pull, uncoil, and raise the blind or
curtain from its roller, so that it covers over the part of, or space in, the carrier or
frame through which the light from the condenser passes to the screen. The
raising of the blind by the cords E, E, when focussed on the screen by the objective
lens of the lantern, produces on the screen the effect of a blind or curtain descending
and obscuring the light, or picture on exhibition.
The withdrawing of the rod G causes the curtain to fall and be rewound on its
roller, producing on the screen, when focussed by the lantern .lens, the effect of a
blind or curtain rising and allowing the light or picture on the screen to be seen.
In the interval between the falling and rising of the curtain the slides or trans-
parencies may be changed or pushed along in the carrier, by hand or otherwise, as
may be desired.
In place of the sliding rod or runner G for raising and lowering the blind,
1 employ, if necessary, a rod, cylinder, or tube, in the upper part of the frame or
carrier, to which the cords E, E, and H, are attached, and which are so arranged
that, on turning the rod, the cords E, E, are wound upon it, and raise the blind,
whilst at the same time, the cord H, previously wound on the rod, is unwound, and
wound up on the blind roller, (to which its other end had been fastened), as the
blind unrolls. The movement of the blind and cords being reversed, the blind is
lowered and rewound on its roller, by turning the rod the opposite way to that
just described.
Or the cords E, E, from the blind may be carried over or through pulleys or
guides at the upper part of the frame or carrier, and back on the opposite side of
the frame to the blind roller, to which the ends of the cords E, E, may be
fastened.
If the blind roller be turned or revolved by a handle or other arrangement, the
blind will unwind from its roller, and, being drawn up by the cords E, E, which,
by the turning of the blind roller, will be coiled round it, will cause the blind to
rise and cover over the space in the carrier through which the light from the
lantern condenser should pass to the screen. By turning the blind roller in the
5 reverse direction to that just described, the movements will be reversed, and
the blind will descend and be rewound on its roller.
Other arrangements may also be employed for raising and lowering the blind.

page_text: The blind and its roller may, if desired, be placed at the upper part of the frame
or carrier, and the rod or other movements for raising and lowering the blind may
be placed in the lower part of the frame or carrier.
The roller blind and the movements for actuating it may, if desired, be fastened
to a frame separate from that used for carrying the slides, or they may be attached
to, so as to form part of, the body or front of the lantern itself.
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 :
Claim 1. The method of producing on a screen, with the aid of an optical or
magic lantern, the effect of a rising and descending curtain, by means of a blind or
curtain wound on a roller which revolves in bearings attached to, or forming part
of, a frame or carrier which can be placed in the stage of the lantern. The
blind or curtain being raised or lowered by means of cords attached by their one
ends to the blind and blind roller, and having their other ends fastened to a rod or
runner working in a groove or guides in the frame or carrier, and so arranged that
on sliding the rod or runner backwards or forwards, the blind may be raised or
lowered in the manner described above.
Claim II. The use of a revolving rod or tube in place of the sliding rod or
runner, for raising' and lowering the blind or curtain, in the manner described
above; or the method of arranging the cords attached to the blind lath over
guides, and fastening their ends to the blind roller, and causing the latter to
-revolve, and the curtain to be unwound and wound on its roller in the manner
before mentioned.
Claim III. The combination of the arrangement described in Claim I or
Claim II, with a "panoramic" or other slide carrier for holding, exhibiting, and
changing slides or transparencies in an optical or magic lantern.
Claim IV. The application of the arrangement of blind, roller, and sliding rod,
and attached or connecting cords, or other movements described in Claim I and
Claim II, to the body or front of the lantern itself, instead of to a separate frame,
or to a slide carrier.
Dated this 23rd day of March 1805