Improvements in and relating to Magic Lanterns, and to the Manipulation of the same.
Year: 1893

page_text: Date of Application, 15th Dec., 1893
Complete Specification Left, 17th Sept., 1894-Accepted, 20th Oct., 1894
PROVISIONAL SPECIFICATION.
Improvements in and relating to Magic Lanterns, and to the
Manipulation of the same.
I, HENRY SIMPSON, of 10 Crooked Lane, Liverpool in the County of
Lancaster, Lamp Manufacturer, do hereby declare the nature of this invention to
be as follows:-
This invention relates to lanterns used for projecting magnified images of slides
on a screen to illustrate lectures and the like, and the object is to provide means
for successively placing in position, in the lantern front, a number of slides which
have been previously placed in proper order in a series of holders; to operate the
dissolving view apparatus, and to intermittently rotate the lime of the lime light;
each of the three operations being performed automatically by the one act of the
operator, who may be at a considerable distance from the lantern.
The present invention comprises certain improvements in the invention set forth
in the Complete Specification of my prior application for Letters Patent, dated
3rd March 1893 and numbered 4644, the result of the present improvements
being a considerable simplification of the construction as therein set forth.
According to my prior Specification aforesaid, the slides are arranged in order
in a chain of slide carriers, which is hung on a square spindle in front of the
lantern condenser, and the slides are brought in succession into the uppermost or
normal position for projection on the screen, by rotating the spindle through
successive arcs of ninety degrees. The slide when in normal position stands close
in front of the condenser, as is usual in lanterns as hitherto constructed, and this
makes it necessary to produce a relative horizontal to-and-fro movement somewhat
greater than the height of a slide, between the square spindle and the lantern,
each time a slide is changed; this horizontal movement is imparted either to the
spindle or the lantern as may be preferred, the one or the other as the case may be,
being mounted on wheels and rails for this purpose.
According to my present invention, I dispense with this horizontal relative
movement, by modifying the condensing lens so that the normal position of the
slide, instead of being, as usual, close in front of the condenser, is in advance of
the latter by a distance somewhat greater than the height of a slide, so that the
slides can clear the condenser as they rotate into position, without the necessity of
such relative horizontal movement.
By this modification, the construction is considerably simplified, and the power
required to operate the apparatus correspondingly reduced.
The structure of the chain of slide holders, the square spindle upon which it is
hung, the articulated dissolving screens, and the lime spindle with its ratchet wheel
and holding pawl, is or may be similar to that already described in my prior
Specification aforesaid, but the square spindle is now journalled in fixed bearings
and the lantern is also fixed.
The motive power may be transmitted, as before, through a flexible tube from a
syringe, actuated by the operator, to a cylinder fitted with a piston and piston rod
and adapted to effect the various movements.
In this case, the lever of the dissolver may be linked to the piston rod and
the latter may actuate a pair of swinging pawls adapted respectively to rotate the
square spindle and the lime spindle, in a manner analogous to that set forth in my
said prior Specification.
In some cases I may make use of a portion of the pressure energy of the
compressed gas in the gas bottle to actuate the apparatus; in this case the gas
bottle is connected to the cylinder by a flexible tube, and the admission to the

page_text: cylinder is controlled by a valve actuated through pneumatic, electrical or any
other suitable means.
As the power necessary to operate the apparatus in its present form is very
small, I may arrange to operate it by a descending weight-such as an iron gas
bottle or by clockwork, a holding pawl or detent being provided to control the
motive power, and the said detent being actuated by the operator through pneu-
matic, electrical or other means.
The mechanism may obviously be arranged in various ways; for instance, the
cord to which the weight is attached, may be wrapped on a prolongation of
the square spindle, or it may be wrapped on an independent spindle geared thereto
by spur or chain gearing or by cranks and linkage. The dissolver and lime spindle
may be operated by a cam on the square spindle or from crank pins or cams on a
secondary spindle geared to the square spindle so as to make a revolution each
time a slide is changed, or the dissolver screens may be arranged to revolve
completely in opening and closing, instead of oscillating merely, and they, as well
as the lime ratchet, may be operated by pulleys and bands from some revolving
part of the mechanism.
As the slides cannot, according to my present invention, be located in normal
position against a fixed abutment, and as their position may not be determined
with sufficient exactness by the chain, I provide a movable abutment or locating
device which is moved to allow the slide to come into position and then engages
with, say, its upper edge, so as to positively locate the slide in focus.
Dated this 14th day of December 1893.
SLOAN & LLOYD BARNES,
Castle Chambers, 26, Castle Street, Liverpool,
Agents for the Applicant.
Improvements in and relating to Magic Lanterns, and to the
Manipulation of the same.
I, HENRY SIMPSON, of 10 Crooked Lane, Liverpool in the County of
Lancaster, Lamp Manufacturer, 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 relates to lanterns used for projecting magnified images of slides
on a screen to illustrate lectures and the like, and the object is to provide means
for successively placing in position, in the lantern front, a number of slides which
have been previously placed in proper order in a series of holders; to operate
the dissolving view apparatus, and to intermittently rotate the lime of the lime
light; each of the three operations being performned automatically by the one act
of the operator, who may be at a considerable distance from the lantern.
The present invention comprises certain improvements in the invention set forth
in the Complete Specification of my prior application for Letters Patent, dated
the 3rd of March 1893 and numbered 4644, the result of the present improvements
being a considerable simplification of the construction as therein set forth.
According to my prior Specification aforesaid, the slides are arranged in order
in a chain of slide carriers, which is hung on a square spindle in front of the
lantern condenser, and the slides are brought in succession into the uppermost or
normal position for projection on the screen, by rotating the spindle through
successive arcs of ninety degrees. The slide when in normal position stands close
in front of the condenser, as is usual in lanterns as hitherto constructed, and this
makes it necessary to produce a relative horizontal to-and-fro movement somewhat
greater than the height of a slide, between the square spindle and the lantern,
each time a slide is changed; this horizontal movement is imparted either to the

page_text: spindle or the lantern as may be preferred, the one or the other as the case may
be, being mounted on wheels and rails for this purpose.
According to my present invention, I dispense with this horizontal relative
movement, by modifying the condensing lens so that the normal position of the
slide, instead of being, as usual, close in front of the condenser, is in advance of
the latter by a distance somewhat greater than the height of a slide, so that the
slides can clear the condenser as they rotate into position, without the necessity of
such relative horizontal movement.
By this modification, the construction is considerably simplified, and the power
required to operate the apparatus correspondingly reduced.
The structure of the chain of slide holders, the square spindle upon which it is
hung, the articulated dissolving screens, and the lime spindle with its ratchet wheel
and holding pawl, is or may be similar to that already described in my prior
Specification aforesaid, but the square spindle is now journalled in fixed bearings
and the lantern is also fixed.
The motive power may be transmitted, as before, through a flexible tube from a
syringe, actuated by the operator, to a cylinder fitted with a piston and piston rod
and adapted to effect the various movements.
In this case, the lever of the dissolver may be linked to the piston rod and the
latter may actuate a pair of swinging pawls adapted respectively to rotate the
square spindle and the time spindle, in a manner analogous to that set forth in my
said prior Specification.
In some cases I may make use of a portion of the pressure energy of the
compressed gas in the gas bottle to actuate the apparatus; in this case the gas
bottle is connected to the cylinder by a flexible tube, and the admission to the
cylinder is controlled by a valve actuated through pneumatic, electrical, or any
other suitable means.
I
As the power necessary to operate the apparatus in its present form is very small,
may arrange to operate it by a descending weight--such as an iron gas bottle-
or by clockwork, a holding pawl or detent being provided to control the motive
power, and the said detent being actuated by the operator through pneumatic,
electrical or other means.
The mechanism may obviously be arranged in various ways; for instance, the
cord to which the weight is attached, may be wrapped on a prolongation of the
square spindle, or it may be wrapped on an independent spindle geared thereto by
spur or chain gearing or by cranks and linkage. The dissolver and lime spindle
may be operated by a cam on the square spindle or from crank pins or cams on a
secondary spindle geared to the square spindle so as to make a revolution each
time a slide is changed, or the dissolver screens may be arranged to revolve
completely in opening and closing, instead of oscillating merely, and they, as well
as the lime ratchet, may be operated by pulleys and bands from some revolving
part of the mechanism.
As the slides cannot, according to my present invention, be located in normal
position against a fixed abutment, and as their position may not be determined with
sufficient exactness by the chain, I provide a movable abutment or locating device
which is moved to allow the slide to come into position and then engage with, say,
its upper edge, so as to positively locate the slide in focus.
In the accompanying drawings I have illustrated the arrangement where the
motive power is transmitted through a flexible tube from the operator to the lantern,
the effect being to operate a piston, the rod of which is articulated to the dissolver
and carries two swinging pawls which operate the spindle carrying the chain of
slide carriers, and the lime spindle, respectively.
Fig. I is an elevation of the arrangement showing the piston at the beginning of
its stroke;
Fig. I is an analogous view showing the piston in about mid-position and
Fig. III is a plan view of Fig. I.
Throughout the drawings the same parts are indicated by the same figures of

page_text: reference, and in Figs. I and II the cylinder in which the piston works and the
bellows are shown in section.
1 is the lantern; 2 the condenser, now so modified that the normal position of
the slide 3 when properly illuminated is, as shown, some distance in front of the
condenser and not close to it as in the usual arrangement. 4 is the lens and 5 a
hood covering in the space between the slide and the lens. 6 is the spindle carrying
the chain of slide-carriers; it may be square as in my prior Specification, but I
prefer in the present arrangement to make it triangular, and the ratchet wheel 7
which operates it has, consequently, three teeth and moves through an angle of
120 degrees each time the slide is changed.
The ratchet wheel is operated by the horizontal movement of the swinging
pawl 8 carried on the bar 9 which is a prolongation of the piston rod 10; the pawl
swings on the pivot 11, and as the piston is forced out, the arm 12 engages with
the teeth of the ratchet wheel and rotates the latter, the pivotal motion of the
pawl being limited by the stop 13 on the bar 9; on the return stroke of the piston
it will be seen that the pawl in passing the ratchet wheel merely swings on its pivot
without operating the ratchet wheel. A similar swinging pawl 14 on the bar 9
operates a ratchet wheel 15 which intermittently rotates the lime spindle 16, and a
detent 17 is fitted to the ratchet wheel 15.
18 is the movable abutment which swings from a pivot 19; the parts which come
in contact with the top edge of the slide, as shown in Fig. I, consist preferably of
two rubber edged rollers 20. The abutment is operated through a rod 21 by the
two armed lever 22 which is raised by the arm 12 of the swinging pawl as it passes,
prior to operating the ratchet wheel, as shown in Fig. II. The lever 22 also
serves as a detent lever for the spindle 6, as it is provided with a pin 23 which
engages in the notches formed in periphery of the detent wheel 24 fixed on the
spindle 6; the raising of the lever 22 by the swinging pawl 8 before the latter
operates the ratchet wheel 7 also serves, of course, to release the detent.
25 is a mask which serves to intercept any rays of light passing from the
condenser outside the slide.
The dissolver 26 is pivoted at 27 and is linked to the piston by means of the
bent arm 28 which engages with the hooked portion 29 of a spring 30 carried from
the rod 9. It is operated as follows;-When the piston is at the beginning of its
stroke the hook 29 engages with the longer portion of the bent arm 28, as shown
in Figs. I and III, and, as the piston makes its outward stroke, the dissolver is
closed, as shown in Fig. II, before the slide 3 begins to rotate. The dissolver
remains closed (in consequence of the longer portion of the bent arm 28 being
supported by the hook 29) whilst the spindle 6 is being rotated and the slide
changed; when, however, the next slide is in position and the piston completes its
outward stroke the hook 29 will have passed from under the arm 28, the latter
will therefore fall by gravity and the dissolver will be opened. When the piston
returns, the hook 29 again engages with the arm, as the latter is prevented from
turning by the stop 31 and the spring 30 yields laterally.
The piston may be operated by the pressure within the cylinder in the usual way
and either air or water pressure may be used, I prefer however when using water
to confine it within a bellows 32 of which the piston 33 forms the end, the
cylinder 34 serving merely to guide the piston. A similar bellows is used by the
operator at the other end of the flexible tube 35 to produce the necessary pressure.
The piston may be returned to normal position by the spring 36 and its motion is
limited by the stop 37.
The construction of the chain of slide carriers 38 is similar to that described in
my prior Specification aforesaid.
Assuming that the slides are placed in the chain of slide carriers in their proper
order and that the first slide is in proper position for projection, the piston being at
the beginning of its stroke, the action of the apparatus, when it is desired to change
the slide, is as follows;-
The operator, by any suitable means, produces a pressure in the fluid the effect

page_text: being to propel the piston and the bar 9 outwardly, the dissolver is closed and the
swinging pawl engages with the roller on the lever 22 thus releasing the detent
and raising the movable abutment; the spindle 6 is next rotated through 120 degrees.
bringing the next slide into position the latter being located exactly by the
abutment, and, as the piston reaches the end of its stroke the dissolver is opened ;
in the meantime the pawl 14 has operated the lime spindle. On releasing the
pressure the spring 36 or the atmospheric pressure returns the piston to its initial
position.
The condenser according to my present arrangement is much larger than usual
and is so constructed as to properly illuminate the uppermost slide of the series.
which is, of course, some distance in front of the condenser.
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. In apparatus for manipulating magic lanterns and in combination, a fixed.
rotatable spindle, a chain of slide carriers adapted to be operated thereby, a lantern
provided with a condeuser which stands clear of the rotating slides and which is
of such size and shape as to be adapted to illuminate the uppermost slide, and
means for rotating the said spindle so as to bring the slides successively into proper
position for projection; substantially as described and illustrated.
2. In apparatus for manipulating magic lanterns and in combination, a fixed
rotatable spindle, a chain of slide carriers adapted to be operated thereby, a
movable abutment adapted to exactly locate the uppermost slide, a lantern provided
with a condenser which stands clear of the rotating slides and is of such size and
shape as to be adapted to illuminate the uppermost slide, and means for rotating
the said spindle and operating the movable abutment; substantially as described
and illustrated.
3. In apparatus for manipulating magic lanterns and in combination, a fixed
rotatable spindle, a chain of slide carriers adapted to be operated thereby, a
movable abutment adapted to exactly locate the uppermost slide, a lantern
provided with a condenser which stands clear of the rotating slides and is of such
size and shape as to be adapted to illuminate the uppermost slide, a hinged
dissolver, and means for rotating the spindle and operating the movable abutment
and the dissolver; substantially as described and illustrated.
4. In apparatus for manipulating magic lanterns and in combination, the
spindle 6, the chain of slides 38, the lantern 1 having a condenser 2 as described,
the movable abutment 18, the hinged dissolver 26, the reciprocating bar 9.
operated as described and carrying the swinging pawls 8 and 14 and the hooked
spring 29 and adapted to operate the spindle 6, the abutment 18, the dissolver 26
and the lime spindle 16; substantially as described and illustrated.
5. The improved apparatus for manipulating magic lanterns; substantially as-
described and illustrated in the drawings.
Dated this 14th day of September 1894.
SLOAN & LLOYD BARNES,
Castle Chambers, 26, Castle Street, Liverpool,
Agents for the Applicant.