An Improved Curtain Slide Carrier for Optical or Magic Lanterns.
Year: 1894

page_text: Date of Application, 20th Aug., 1894-Accepted, 29th Sept., 1894
COMPLETE SPECIFICATION.
An Improved Curtain Slide Carrier 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 an arrangement, for use in an optical lantern, of a sliding
runner attached to a mask or shutter, or to a blind or curtain wound on a roller, so
as to raise and lower same, as described below, and produce on a screen, when
focussed by the lantern lens, the effect of a rising and descending curtain, in
combination with a panoramic or other carrier or slide frame for exhibiting lantern
slides or transparencies.
Any form of carrier or slide frame may be employed, but the carrier I prefer to
use is shewn in drawing II, made of such length that it will hold four ordinary
lantern slides, 3 x 31, at the same time.
The cross pieces A are placed at such distances that when two slides have been
placed in the groove of the carrier and pushed along till the second slide is flush
or level with the edge of the cross pieces A, the first slide will occupy the space
between the cross pieces B and C, opposite the condenser of the lantern, in the
proper position for exhibition on the screen. A third slide can then be placed in
the carrier and, when pushed along-till the edge is flush with the edge of the cross
pieces A, the second slide will be opposite the condenser. A fourth slide can then
be placed in the carrier ready to be pushed along, the first slide being removed to
prevent it from falling out when the fourth slide is pushed along. A stop may be
employed at the end of the carrier groove against which the first slide will press,
so that the fourth slide cannot be pushed along until the first slide has been
removed. Springs are affixed to the sides of grooves to keep the slides in position,
and allow for difference of thickness of-the slides.
The arrangement for producing the rising and descending curtain effect consists
of a mask or shutter of thin metal or other material, preferably about four inches
square, running in guides which are fastened in a vertical position upon, or form
part of, the cross pieces B and C. A rod or runner of wood or other material
slides in a groove or guides cut in the upper part of the carrier, as shewn in
drawing at D. The mask or shutter is attached to the runner by flexible cords of
silk or other material, which pass through staples or other contrivances acting as
guides. When the runner is pushed along, it draws up or raises the mask or
shutter so as to cover the part of the carrier between the cross pieces B and C,
through which the light from the condenser passes, and produces on the screen,
when focussed by the front lens of the lantern, the effect of a curtain descending
and obscuring the light or picture.
When the runner is drawn back the reverse way the mask or shutter falls, and
produces on the screen the effect of a curtain being raised and allowing the light or
picture to be seen.
A slot is cut in the cover of the groove in which the runner slides, and through
this slot a pin or handle is fastened to the end of the runner, by which the latter is
moved to and fro, but other means may be employed for working the runner.
In working the combined curtain and carrier, the runner is first pushed along so
as to raise the mask,-the carrier will then go into any ordinary lantern front,-and,
if the stage of the lantern is an open one, on withdrawing the runner the mask or
curtain will fall below the stage, leaving the opening of the carrier clear for the
light from the condenser to pass

page_text: Two slides having been placed in the carrier so that the first one occupies the
space in front of the condenser, a third slide is then placed in the carrier.
The runner being pushed along raises the mask and produces on the screen the
effect of a curtain descending and obscuring the picture. The third slide in the
carrier is then pushed along till flush with the cross pieces, as described above,
causing the second slide to be in position opposite the condenser, and the runner is
then withdrawn, producing on the screen the effect of a curtain rising and disclosing
a fresh picture.
In place of the sliding runner movement, the raising and lowering of the curtain
may be produced by a rod or roller, working in bearings, which are fixed to the
upper part of the carrier, and to which the flexible cords from the mask or shutter
are attached, and wound upon or unwound by the revolving of the rod, (see
drawings III and IV).
An alternative method for producing the curtain effect which I employ, consists
of a roller E. running in bearings, F. F. which are fixed to the underpart of the
slide carrier as shewn in drawing IV. Springs G. G are attached on each side,
near the bearings, one end to the base of the carrier and the other end to the
roller, in such manner that the revolving of the roller in one direction will coil up
the springs, and in the reverse direction will uncoil them. To this roller 1 fasten a
blind or curtain of cloth or other material, which winds up on the roller, and is of
such dimensions that, when unwound, it will cover the opening of the carrier
through which the light from the condenser passes when the carrier is in use in the
lantern.
A runner sliding in a groove or guides at the upper part of the carrier, similar to
the arrangement already described, is employed to work the curtain.
The curtain is attached to the runner by flexible cords which pass through gnides
as before described, in such manner that, on sliding the runner along its groove,
the blind or curtain is unwound from its roller and drawn up so as to cover the
opening in the carrier and obscure the light or picture on the screen, at the same
time coiling up the springs of the blind roller. On withdrawing the runner, the
curtain, assisted by the uncoiling of the springs, is lowered and rewound on its
roller. In place of the sliding runner movement, the raising and lowering of the
curtain may be produced by a rod or roller working in bearings which are fixed to
the upper part of the carrier, and to which the flexible cords from the blind or
curtain are attached, and wound upon or unwound by the revolving of the rod.
The methods above described for producing on a screen the effect of a rising and
falling curtain, being independent of the movements for pushing the slides into
position, permit of the carrier being used with or without the curtain effect as
desired.
These methods of producing a curtain effect on a screen also allow of their being
used or adapted to other forms of carriers or slide frames already in use.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The arrangement of a sliding runner, or a revolving rod, attached to a
mask or shutter, so as to raise and lower same, as described above, and produce
ou a screen, when used in an optical lantern, the effect of a rising and falling
curtain.
2. The combination of the above arrangement with a panoramic or other carrier
or slide frame for exhibiting slides or transparencies in an optical lantern.
3. The method of producing on a screen, by means of an optical lantern, the
effect of a rising and falling curtain by the use of a blind or curtain attached to
and winding up on a roller which runs in bearings fastened to the base of the
carrier, and has springs attached to it and to the base of the carrier, as described
above. The whole arrangement being worked by a runner sliding in a groove or
guides in the upper part of the carrier, and being attached to the curtain by

page_text: flexible cords as before mentioned; or, alternatively, being worked by a revolving
rod, as described above.
4. The combination of the arrangement described in Claim 3, with a carrier or
slide frame for exhibiting slides or transparencies in an optical lantern.
Dated this 20th day of August 1894.
GEORGE DAVENPORT.