Improvements in Collapsable Magic Lanterns.
Year: 1894

page_text: Date of Application, 23rd June, 1894-Accepted, 1st Sept., 1894
COMPLETE SPECIFICATION.
Improvements in Collapsable Magic Lanterns.
1. ALFRED WRENCH, of 50, Gray's Inn Road, in the County of London,
Manufacturing Optician, 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 :-
My invention relates to magic lanterns, and has for its object to provide a lantern
which can be folded or collapsed into a much smaller space than a lantern of similar
capabilities (as regards the diameter of the dise illuminated and the focus) as here-
tofore constructed and also to provide means whereby the lantern when extended
or opened out will be more rigid than heretofore.
A lantern constructed according to my invention has a metal body having at the
back a hinged door and on the inside of the front a cell for carrying the condenser.
To the front of this body is fitted a frame carrying the staging for the slides and
having connected to it by lazy-tongs levers the front plate carrying the objective
mount, screws being provided for fixing the lazy-tongs levers and so ensuring the
rigidity of the extensible portion of the lantern. The space between the said frame
and the plate carrying the objective mount is provided with a leather bellows.
The objective lenses and some other loose parts are adapted when the lantern is
folded up or collapsed to be carried in a box or case designed to fit within the
lantern body, and the lantern body itself with all the parts which it contains are
enclosed in an outer box.
To enable my invention to be fully understood I will describe the same by
reference to the accompanying drawings, in which :-
Figure 1 is a sectional side elevation shewing my improved lantern extended;
aud,
Figure 2 is a sectional plan of the same:
Figures 3 and 4 are side and end views respectively of the box for containing the
lantern and its accessories :
Figure 5 is a section on the line 5-5, Figure 4, shewing the lantern within
the box:
Figure 6 is a rear elevation of the lantern body with part of the hinged cover
broken away, the said view also shewing the position of the front plate of the
extensible portion of the lantern when the same is folded up within the said
body:
Figures 7 and 8 are an elevation and plan of the box for containing some of the
accessories:
Figures 9 and 10 are side and end elevations respectively of the lantern chinney;
and,
Figure 11 is a plan view illustrating the construction of the bellows.
Similar letters of reference indicate corresponding parts in the several figures.
a is the lantern body which is preferably formed of Russian iron, and a' is the
door at the rear of the said body, the said door as shewn being hinged to the top
of the body, and b, bare sight holes formed in the sides of the body and in the door
and provided with coloured glass in a well known manner. c is a chimney (shewn
detached in Figures 9 and 10) having its lower edge slit to enable it to be sprung
into a hole or aperture c' formed in the top of the body. d, dare ventilating holes
iormed respectively in the top and bottom of the body, and d' are shields placed
inside the top of the body to prevent light from shewing through the holes d. e is
the cell for containing a condenser in a metal mount.
The frame carrying the staging and the extensible portion of the lantern

page_text: comprises a plate adapted to slide in, and be held against the front plate of the
body a, by guides on the latter, pillars fixed to the plate carrying
another plate g to which the extensible portion of the lantern is directly connected.
The plates, are provided with central apertures for the passage of the light and
the space between the said plates is occupied by the staging for the slides, being
the spring-plate by means of which the slides are held in position, and, guide-
pins for the said plate, the said pins sliding in holes in the plate g.
i, i are the lazy-tongs levers carrying the plate in which the objective mount k
is fixed. In practice I use three sets of such lazy-tongs levers, namely, one set at
each side of the extensible portion of the lantern and one at the bottom, each set at
each end having one of its levers pivotted at 1 to a flange upon the plate to which
it is connected and having the other lever at each end provided with a clamping
screw m and nut mº, the said clamping screw sliding through a slot m' also formed
in the flanges of the plates and for fixing the lazy-tongs in any position in which
the extensible portion of the lantern is placed. In practice the clamping screws in
are made with lever extensions, as shewn, to facilitate the tightening of the same
and the plates g, are cut away as shewn in Figure 6 to allow of free movement for
the said screws when the levers i, i are extended.
9
The plates, and jare provided with feet or extensions Pat the bottom to
support the extensible portion of the lantern in the proper plane relatively with the
body a, the spaces between the feet serving to allow the said plates to pass the
shields d' when the extensible portion is placed inside the body as shewn in
Figure 6.
indicates the leather bellows which is fixed between the plates and in the
space between the sets of lazy-tongs levers i. In order to permit of the bellows
being readily removed, for instance, in cases when the lantern is to be used as a
science lantern I attach the ends of the said bellows to plates n', n' as shown most
clearly in Figure 11, the said plates being designed to slide in grooves n³, n³ on the
plates g and j, Figure 2.
I prefer that the extensible portion of the lantern should have a range of
adjustment of 12 inches which is sufficient for a 12 focus front or objective lens,
but as provide my lantern with objective lenses of varying foci the extent to
which the extensible portion of the camera is opened is according to the focus of
the particular lens used.
ין
The objective lens k' is carried by a tube adapted to be held by a tube k³ in
the mount the tube being arranged to he moved by a rack and pinion to
permit of accurate focussing and the fronto (attached to the tube ³) is formed
with a slot into which coloured pieces of glass may be introduced for tinting
purposes; a shutter hinged at q' is also connected to the said front piece o.
is an oxy-hydrogen burner of ordinary construction which is carried upon a
pillars fixed to a bar or tray sliding in guides u, u on the bottom of the lantern
body a.
Figures 5, 7 and 8, is the box or receptacle into which certain of the accessories
of the lantern are packed, to, to being the compartments for the objective lenses and
the chimney c, and w² the compartment into which the oxy-hydrogen burner is
placed.
is the box into which the whole apparatus is packed, the lid of which box is
provided with a catch or clasp for retaining the lid closed, and is a strap which
is provided for facilitating the carrying of the said box.
The mode of packing the apparatus is as follows:-The frame with the staging
and extensible front portion of the lantern are first detached from the body a and
after the screws m, mare loosened the extensible portion is collapsed; the lens
and the tube are then removed from the tube of the mount & and placed in
one of the compartments we of the case and the front o is removed from the tube k²
and screwed onto the end of the tube 4, the mount & with the said front o is then
removed from the plate j and again screwed into the opening from the inside of the
hellows (this position being shown in Figure 5). The bar or tray with the oxy-

page_text: hydrogen burner is also removed from the body a and the whole of the extensible
portion is then put within the said body with the feet 1° uppermost, the condenser
cell e projecting through the openings in the plate and the spring-plate h also as
shewn in Figure 5. The case for containing the accessories is then introduced
into the body and finally the bar or tray carrying the burner standard sis
introduced into its guides, ; the door u¹ is then closed and the whole lantern is
introduced into the box and secured therein by the clasp y and strap z.
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. A magic lantern having the front or objective lens carrying plate connected
by lazy-tongs levers to the other part of the lantern, clamping screws or the like
being provided for fixing the said lazy-tongs in order to rigidly hold the objective
lens in any required position, substantially as described.
2. In a magic lantern the combination with a body carrying a condenser and
adapted to receive a lamp or burner of a framing supporting a staging for the
slides and having connected with it lazy-tongs levers supporting the front lens
carrying plate, the said framing with the extensible portion being adapted to enter
guides on the front of the body portion of the lantern, substantially as described.
3. In a magic lantern having the front adapted to be extended by means of
lazy-tongs levers, collapsable movable bellows arranged between the said levers
and having end plates adapted to enter guides in the plates to which the lazy-tongs
levers are united, substantially as, and for the purpose described.
4. In a portable magic lantern, the combination of a body, an extensible portion
designed to be fitted to the front of the said body and when folded up to be
inserted within the said body, and a box or case for containing lantern accessories,
the whole being designed to be enclosed in an outer box or case, substantially as
described.
5. The manufacture and use of the improved collapsable magic lantern herein-
before described and illustrated in the accompanying drawings.
Dated the 23rd day of June 1801
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.