An Improved Optical Lantern.
Year: 1894

page_text: Date of Application, 16th Aug., 1894
Complete Specification Left, 17th June, 1895-Accepted, 3rd Aug., 1895
An Improved Optical Lantern.
JOHN AIRS Scientific Instrument Maker 152 Farringdon Road, W.C., do
hereby declare the nature of this invention to be as follows:
To simplify the working of a single or multiple optical lantern by having a
hinged frame on the forward end of the lantern, upon which the front or fronts
are mounted, and by suitable mechanism, can adjust the planes of the front or
fronts together or separately so that the discs of light occupy the same position on
a given space. The object of the frame being hinged to the forward end is to give
access to the inside of the lantern and to the condensers.
August 16th 1904
An Improved Optical Lantern.
I, JOHN AIRS, Scientific and Instrument Maker, 152 Farringdon Road W.C.,
do hereby declare the nature of my said invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement :-
The object of my invention is to simplify the working of a single or multiple
optical lantern. by having a hinged frame on the forward end of the lantern
upon which the front or fronts is or are mounted, and by suitable mechanism
adjusting the plane of the fronts together or separately, so that the discs of light
may occupy the same position on a given space. The object of the frame being
hinged to the forward end is to give access to the inside of the lantern and the
condensers.
And in order that my said invention may be particularly described and ascer-
tained reference is hereby made to the accompanying drawings, in which similar
figures of reference indicate corresponding parts.
Fig. 1 is a side elevation, Fig. 2 a plan, and Fig. 3 a front elevation of a bi-unial
lantern fitted according to my invention.
Fig. 4 is an enlarged sectional elevation of the separate frame on the line ab of
Fig. 3 looking towards the right, and Fig. 5 is a similar sectional elevation on the
line ab of Fig. 3, looking towards the left, showing also suitable internal
mechanism.
For the purpose of gaining access to the inside, 1 mount the front or fronts of
single or multiple lanterns in a separate frame 6, upon vertical pivots 7, 7; the
method of opening the front being indicated by dotted lines in Fig. 2. The frame
and lantern fronts may be readily detached on removing one or both of the
pivots 7, 7.
For adjusting the fronts in altitude a three-armed lever 12 is fitted to one end of
an axle 13 and a double-armed lever 17 is fitted to the other end of the same axle.
The axle 13 extends from side to side of the frame 6. 9 is a milled headed screw
to which a travelling nut 10 is fitted. A link 11 is pivoted to the nut 10, and also
27

page_text: to the three armed lever 12. The frames 18 are pivoted at 8, 8, 8, to the frame 6.
and at 24 to the lever 22, hereinafter described. Pairs of connecting rods 14
and 15 are fitted to the ends of the levers 12 and 17 and to the triangular frames 18
forming parts of the lantern fronts, as shown in Figs. 4 and 5. By means of the
screw 9 the levers 12 and 17 can be turned simultaneously with the axle 13, and
the combination of the screw 9, nut 10, link 11 levers 12 and 17, axle 13, and
connecting rods 14 and 15, enables the operator to adjust the altitude of the
projected discs of light, so as to occupy the same position of altitude on a given
space.
For adjusting the fronts in azimuth another milled-headed screw 19 is fitted
having a travelling nut 20. (Fig. 4). 21 is a link to which the bent lever 22 is
pivoted. The upper end of this lever is pivoted at 23 to the frame 6. At 24 the
lever 22 is pivoted to one side of the upper lantern frame 18. The combination of
the adjusting screw 19, nut 20, link 21, and lever 22, enables the operator to adjust
the azimuth of the upper front to that of the lower front, so that the discs of light
may occupy the same position on a given space. If preferred the azimuth
regulating mechanism may be fitted to the lower front instead of the upper.
By means of obvious modifications, my invention may be adapted to single or
multiple lanterns otherwise arranged and mounted, for effecting the purposes
aforesaid; and mechanism, other than that described, may be used, without
departing from the principle of my invention.
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 :-
1. The improved optical lantern, substantially as and for the purposes described.
2. The improved method of mounting single and multiple optical lantern fronts in
detachable pivoted frames 6, upon vertical centres substantially as and for the
purposes hereinbefore described and illustrated by the drawings.
3. The improved method of mounting multiple lantern fronts, whereby they are
rendered adjustable for registering the altitude and azimuth substantially as
hereinbefore described and illustrated by the drawings.
4. The improved method of mounting multiple optical lantern fronts in separate
detachable frames, pivoted upon vertical centres, and pivoting each lantern front
upon horizontal centres in the separate frame, for registering the altitude; in com-
bination with means and appliances for registering the azimuth, so that the
projected dises of light may occupy the same position on a given space, substantially
as hereinbefore described and illustrated by the drawings.
5. In combination with optical lanterns mounted as aforesaid, the application
and use of the mechanism for operating the same, substantially as hereinbefore
described and illustrated by the drawings.
Dated 15th June 1805
GEO.
DOWNING,
8 Quality Court, London, W.C., Agent.