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

page_text: Date of Application, 3rd Mar., 1893
Complete Specification Left, 4th Dec., 1893-Accepted, 3rd Mar., 1894
TRUVIDIONAL SPECIFICATION.
Improvements in and relating to Magic Lanterns and to the
Manipulation of the same.
1, 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:-
The object of my invention 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 rotate
the lime of the lime light, each of the three operations being performed
automatically by the one act of the operator.
I construct such apparatus as follows;-As already stated, the slides are placed
in a series of holders, one for each slide, the holders being preferably made with
spring arms which hold the slides; at one end, the holders are made integral with
or rigidly attached to the links of a pitch chain, each to each, the rivets of the
chain being of considerable length, and the slides when in their holders stand
parallel to each other and perpendicular to the axis of the chain; provision is
made for readily articulating or disarticulating the links so that whatever the
number of slides they may be arranged on an endless chain.
The chain of slides is hung above on a square pulley, the sides of the square
being equal to the pitch of the chain and the sides being normally horizontal and
vertical; in this position it will be seen that of the three slides whose links are in
gear with the pulley, the central one is vertical and the other two are horizontal.
The pulley is so placed with reference to the condensing lens of the lantern that
the central slide aforesaid is in the correct position, close in front of the condensing
lens, for projection upon the screen, and the next slide of the series is lying
horizontally close below the said lens. In order to bring this next slide into
position it is necessary first, either to draw the pulley, and with it the chain of
slides forward a distance somewhat greater than the height of a slide, or keeping
the pulley stationary, to move the lantern back by this amount,--secondly, to
rotate the pulley through ninety degrees, and thirdly to push the pulley or the
lantern as the case may be back into normal position, bringing the slide into focus
close in front of the condenser.
I effect these movements as follows;-I mount the pulley spindle or the lantern
as the case may be upon a slide or upon wheels or on the ends of pivoted links so
that it is adapted to be moved over the necessary horizontal distance, and I impart
the said horizontal movement by a crank and connecting rod, the crank making a
complete revolution each time a slide is changed so as to move the pulley or the
lantern forward and backward. When the lantern is fixed and the pulley and
slides move, a ratchet wheel on the pulley spindle engages just before the latter
reaches the end of its forward stroke with a fixed pawl or detent which causes it to
rotate through ninety degrees and I provide means for preventing any rotation of
the pulley other than that which is so caused. When the slide returns to normal
position it is elastically pressed against adjustable stops so as to bring it exactly
into focus.
When the lantern is moved and the pulley spindle has a motion of rotation only,
the pawl which operates the ratchet wheel on the pulley spindle is fixed to the

page_text: lantern and the latter is operated to and fro by the crank shaft in the manner
described in reference to the pulley spindle, so that just before the lantern reaches
the end of its backward stroke the pawl attached thereto operates the ratchet
wheel.
The motive power for actuating the crank shaft is preferably a descending
weight, which may conveniently be an iron gas bottle when one is used, a suitable
stirrup being provided to sling it in. The rotation of the crank shaft is preferably
controlled by a pawl or an escapement operated electro-magnetically or pneu-
matically, as this permits the operator to be at a considerable distance from the
lantern. The control may however be purely mechanical, if preferred, by a cord,
rod or the like and if preferred the driving weight may be dispensed with and the
motive power applied by an electromotor or pneumatically or mechanically, under
the control of the operator.
Any of the well known forms of dissolver may be used and it is operated by the
revolution of the crank shaft by means of endless bands and pulleys or by links
and levers as may be most convenient.
I find it convenient when the dissolver is to be operated by a crank shaft to use
a dissolver consisting of two shutters or screens of metal or coloured or plain
translucent material placed in front of the projecting lens, one of the screens being
pivoted at its apper edge above the lens, and the other at its lower edge below the
lens. The pivots or spindles of the screens are sufficiently clear of the lens to
allow the screens to revolve and they are actuated by pulleys and bands from the
crank shaft so as to make turn for turn with the latter. While a slide is in focus
the upper screen stands vertically over its spindle and the lower one hangs
vertically below its spindle, thus leaving the lens perfectly unobstructed. While
the slide is being changed the screens swing towards each other, overlap and finally
after completing a revolution return to their normal positions.
રા
The means for rotating the lime of the lime light are as follows;-- provide
spindle carrying a spur wheel adapted to gear with the ordinary gear wheels of the
lime holder, and carried on a slide from the side of the lantern which can be
adjusted to suit the position of the lime. This spindle has a ratchet wheel fixed to
it and provide an adjustable pawl which is operated by each revolution of the
crank shaft and turns the said ratchet wheel through one or more teeth so as to
rotate the lime each time a slide is changed.
When the lantern is moved to allow the slides as they rotate to clear the
condenser, it will be seen that the ratchet wheel on the lime spindle partakes of the
reciprocating motion of the lantern and to operate it, it is only necessary to have a
fixed pawl which engages with the ratchet wheel each time it moves past it in one
direction but which does not operate it as it returns.
In some cases I have found it objectionable to operate the mechanism through
a crank shaft and in such cases I prefer to move the pulley spindle or the lantern
as the case may be in one direction by means of a piston operated by air pressure,
the return stroke being effected by means of a weight or spring or by suitably
inclining the rails on which the wheels which support the spindle or the lantern run.
I find this construction very convenient when the lantern is moved to allow the
slides to clear the condenser in which case the piston rod is attached to the lautern
and pushes it back and just before it reaches the end of its stroke a pawl fixed to
the lantern or the piston rod operates the ratchet wheel on the pulley spindle and a
second pawl fixed also to the piston rod operates the dissolver so as to close it
before the pulley spindle is rotated; in this case the dissolvers consist of two
overlapping shutters the spindles of which are so articulated or connected together
that the one operates the other.
When the pressure on the piston is relieved the lantern is caused to return by a
spring or weight or by its own weight and just before it reaches its normal position
it opens the dissolver.
I prefer to mount the lime spindle horizontally so that the
ratchet wheel is vertical and better adapted to gear with the fixed pawl.
The lantern must be mounted on a stand sufficiently high to allow the chain of

page_text: slides to hang clear of the floor and to allow for the descent of the weight if one is
used.
Dated this 1st day of March 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 performed automatically by the one act of the
operator who may be at a considerable distance from the lantern.
As stated, the slides are placed in a series of holders, one for each slide, which
are made integral with or rigidly attached to the links of a pair of endless pitch
chains, the arrangement being such that the slides lie between the chains with their
planes perpendicular to the axes of the chains. The chain of slides is hung above
on a square spindle, the sides of the square conforming with the pitch of the chain
and standing normally horizontally and vertically, so that of the three slides whose
links are in gear with the spindle the central or uppermost slide is vertical and the
other two are horizontal. The square spindle is so located with reference to the
condensing lens of the lantern that the central or uppermost slide aforesaid is in
the correct position, close in front of the condensing lens, for projection on the
screen, and the next slide of the series is lying horizontally close below the
said lens.
The slides are successively brought into the uppermost position ready for
projection on the screen by rotating the square spindle through successive arcs of
ninety degrees and from the described normal positions of the slides it is clear that,
in order to permit the slides to so rotate into the uppermost position, it is necessary,
each time a slide is changed, to produce a relative horizontal movement between
the square spindle and the lantern, somewhat greater than the height of a slide.
I find that the most convenient method of conveying the power to operate the
apparatus is by pneumatic means. A cylinder fitted with a piston and rod is
attached to the lantern and is connected by a flexible tube to a pneumatic syringe
actuated by the operator. By this means a horizontal to-and-fro movement of
either the square spindle or the lantern as the case may be, is effected, and the
same movement is used to rotate the square spindle, to operate the dissolving
apparatus and to rotate the lime-all as hereinafter more particularly described.
In the accompanying drawings Figs. I to V show the arrangement when the to-
and-fro movement is imparted to the spindle upon which the chain of slides is hung,
and Figs. VI and VII show the arrangement when the said movement is instead
imparted to the lantern.
Throughout the drawings the same parts are indicated by the same reference
figures.
"Referring first to Figs. I to V. Fig. I is a side elevation, the greater part of

page_text: the chain of slides being broken away to save height; Fig. II is a side elevation in
medial vertical section excepting as regards the dissolving apparatus; Fig. III is
a plan view, the hood 6 the chain of slides and the top of the lantern being
removed; Fig. IV is a sectional elevation on the line A. A. of Fig. I looking
towards the lantern, and Fig. V shows to a smaller scale, the arrangement of the
lantern on its stand.
1 is the lantern fixed to the base 2, 3 is the condensing lens, 4 the projecting lens,
5 the dissolving screens, 6 a removable hood to prevent diffusion of light and
7, (Figs. II and III,) the lime block spindle.
8 are the endless pitch chains which carry the slide holders; each holder consists
of an open frame 9 (Fig. II) of thin sheet metal within which the slide 10 fits
freely, with a pair of elastic arms 11 adapted to hold the slide in position. Each
frame is formed integral with or rigidly attached to a link of each chain and forms
a bridge between the chains, the tension of which keeps the planes of the slides
perpendicular to the axes of the chains or approximately so. Some or all of the
pins of the chains are made removable so that the chains can be readily articulated
or disarticulated in order that, whatever the number of slides, they can be arranged
in an endless series.
12 is the square spindle over which the chain of slides is hung; the sides of the
square conform with the pitch of the chain so that each quarter revolution brings
a slide into the vertical position. The spindle 12 is journalled on the light truck 13
which runs on the wheels 14 on the rails 15, 16 being guard rails to prevent the
accidental displacement of the truck. The chain of slides is steadied below by a
pulley 17 (Fig. V.), carried on the frame 18 carried from the truck; this frame is
telescopic so that it can be adjusted to suit the length of the chain of slides; the
adjustment is made by sliding the lower part of the frame through the socket 19
(Fig. V.), and clamping by the screw 20.
25 is a
21 is the pneumatic cylinder attached to the lantern for actuating the apparatus ;
it is connected by the flexible tube 22 to a pneumatic syringe which is placed in a
convenient position to be manipulated by the operator. The piston rod 23 is
attached at 24 to the end of the square spindle 12 and is adapted to propel it with
its truck to-and-fro from its normal position at the right shown in the drawings to
its extreme position at the left shown in dotted lines at 12' in Fig. II.
four-armed ratchet wheel secured to the spindle 12 and adapted to engage with the
pawl 26 which is pivoted to the fixed framing of the lantern and whose motion is
limited by the stop pin 27. 28 is a holding pawl pivoted on the truck 13 aud
engaging with the notched wheel 29 and preventing any rotation of the spindle 12
except that which is intended.
The action of this part of the apparatus is as follows;-The operator makes the
down stroke of his syringe and produces pressure in the cylinder 21 so expelling
the piston rod 23 and driving the truck 13 and all its attachments to the left. As
soon as the slides are clear of the condensing lens, the roller 30 fixed to the holding
pawl 28 encounters the top of the pawl 26 and lifts 28 clear of 29 and immediately
afterwards the ratchet wheel 25 engages with 26 and turns the spindle 12 through
ninety degrees, so changing the slide. 31 is a light buffer spring to gently arrest
the truck. The operator now makes the up-stroke of his syringe and the rarefaction
so caused in the cylinder 21 retracts its piston rod 23. During the return stroke
the pawl 26 swings freely and is therefore inoperative and the only effect is to
bring the slides back into normal position the uppermost one abutting against the
fixed stop 32. 33 is an elastic pawl fixed to the truck and engaging in succession
with the edges of the slides. It serves the double purpose of ensuring that the
edge of the horizontal slide shall not rise so high as to foul the condenser in the
return stroke, and also to maintain an elastic pressure between the top edge of
the uppermost slide and the stop 32 so ensuring that this slide shall not tilt forward
out of focus.
The dissolving apparatus consists of a pair of overlapping pivoted screens 5, 5, of
opaque or translucent material, plain or coloured. The levers 34 are secured to

page_text: the screen spindles and linked together by the link 35 so that the screens co-operate
in opening and closing. The lower lever 34 is prolonged and linked by the link 36
to the end of the piston rod 23. Normally the dissolver screens are open as shown
in full lines; as the piston rod 23 is expelled the screens gradually close and at the
end of its stroke when the slide is changed, the screens are closed as indicated in
dotted lines in Fig. II; as the slide travels back into focus, the dissolver gradually
opens again. I find that the gradual movement of the slides out of and into focus
combined with the closing and opening of the screens gives an excellent dissolving
effect.
The device for rotating the lime block is shown in Figs. II and III. The lime
spindle 7 is mounted horizontally instead of vertically as usual, with the object of
saving gearing. It is provided with the ratchet wheel 37 having a holding
pawl 38 and adapted to engage with the swinging pawl 39 mounted on the
truck 13. Each movement of the truck to the left turns the wheel 37 one tooth,
the return movement being inoperative. In order to allow the lime to be adjusted
into focus, the spindle 7 and pawl 38 are mounted on a sliding plate 4" which can
be clamped by the screw 41.
The lantern is set upon a stand as shown in Fig. V sufficiently high to allow the
chain of slides to hang freely. The legs 42 and diagonal braces 43 are preferably
made detachable for the sake of portability.
It is clear from the description given that by a single up and down stroke of his
syringe, the operator who may be at a considerable distance from the lantern,
effects all the operations required, that is to say, to bring the slides successively
into position, to work the dissolver, and to intermittently rotate the lime block.
The modified form of the apparatus shown in Figs. VI and VII is substantially
similar to that already described, with the exception that the to-and-fro movement
is here imparted to the lantern which is mounted on wheels, and the square spindle
which carries the chain of slides is mounted on fixed bearings.
Figs. VI and VII are views analogous respectively to Figs. I and II, but the
apparatus is not shown in normal position but at the opposite end of the stroke.
The pawl which rotates the square spindle is now mounted on the arm 44
attached to the lantern, the dissolving lever is linked to the lantern, and the pawl
for operating the lime spindle is mounted on a fixed pivot on the bracket 45
which also carries the spring pawl for restraining the slides as they ascend. The
buffer spring 31' is now placed at the rear of the lantern and the depressions 46 in
the rails serve to definitely locate the lantern when in normal position.
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 improved apparatus for manipulating magic lanterns which consists of
an endless chain of slide carriers mounted on a spindle adapted to rotate and
bring the slides successively into a vertical position in front of the condenser of
the lantern, and means for producing the necessary rotation of the spindle and
relative horizontal movement between the chain of slide carriers and the lantern,
to permit the rotation of the successive slides into the vertical position, substan-
tially as described and illustrated.
2. The improved apparatus for manipulating magic lanterns which consists of
an endless chain of slide carriers mounted on a spindle adapted to rotate and bring
the slides successively in a vertical position, the said spindle being mounted on a
truck and means being provided to move the said truck horizontally, relatively to
the lantern, and to rotate the said spindle, substantially as described and
illustrated.
3. The improved apparatus for manipulating magic lanterns which consists of
an endless chain of slide carriers mounted on a spindle adapted to rotate in fixed
bearings and bring the slides successively into a vertical position, a lantern
mounted on wheels and means for moving the said lantern horizontally, relatively

page_text: to the chain of slide carriers, and rotating the said spindle, substantially as
described and illustrated.
4. In combination with the chain of slide carriers and the lantern as claimed in:
Claim 2, a pair of hinged and articulated shutters adapted, when closed, to
intercept the rays of light from the lantern, and a rotatable lime spindle, the
shutters being vibrated and the lime spindle rotated by the movement of the truck
which carries the chain of slide carriers, substantially as described and illustrated.
5. In combination with the chain of slide carriers and movable lantern as
claimed in Claim 3, a pair of hinged and articulated shutters adapted, when
closed, to intercept the rays of light from the lantern, and a rotatable lime spindle,
the shutters being vibrated and the lime spindle rotated by the movement of the
lantern, substantially as described and illustrated.
6. In combination with the fixed lantern and the chain of slide carriers, a spindle
supporting the said chain and carried by a truck and having a ratchet wheel
which as the truck moves engages with a fixed pawl which rotates it through the
requisite angle, substantially as described and illustrated.
7. In combination with the chain of slide carriers and the movable lantern, a
spindle supporting the said chain and carried in fixed bearings and having a ratchet
wheel adapted to be operated by a pawl carried by the lantern which, as the
latter moves, rotates the said spindle through the required angle, substantially as
described and illustrated.
8. In combination with the fixed lantern, the chain of slide carriers carried by
a movable truck, the hinged and articulated shutters operated by a link connected
to the said truck, and a rotatable lime spindle having a ratchet wheel rotated by
a pawl carried by the said truck, substantially as described and illustrated.
9. In combination, the chain of slide carriers, the movable lantern, the hinged
and articulated shutters operated by a link connected to the lantern, and a
rotatable lime spindle having a ratchet wheel rotated, as it moves with the lantern,
by a fixed pawl, substantially as described and illustrated.
10. In combination with a lantern and a rotatable spindle carrying a chain of
slide carriers, the herein described means for producing relative movement between
the chain of slide carriers and the lantern which consists of a cylinder fixed to
the lantern the piston rod of which is attached to the said spindle, the movement
being obtained by pneumatic pressure, transmitted by a tube to the cylinder,
substantially as described and illustrated.
11. In combination with a lantern and a spindle capable of rotation, a chain of
slide carriers consisting of two pitch chains, the opposite links of which are
connected by open frames which form the slide carriers, substantially as described
and illustrated.
12. The combination and arrangement of parts forming the improved apparatus
for manipulating magic lanterns, substantially as described and illustrated in
Figs. I to V.
13. The combination and arrangement of parts forming the improved apparatus
for manipulating magic lanterns, substantially as described and illustrated in
Figs. VI and VII.
Dated this 2nd day of December 1893.
SLOAN & LLOYD BARNES,
Castle Chambers, 26, Castle Street, Liverpool,
Agents for the Applicant.