IMPROVEMENTS IN SIGNAL AND OTHER LAMPS AND LANTERNS AND IN LENSES THEREFOR "
Year: 1883

page_text: LETTERS PATENT to Joseph Rogers of N° 16 Hanover Square in the County
of Middlesex for an Invention of "IMPROVEMENTS IN SIGNAL AND OTHER
LAMPS AND LANTERNS AND IN LENSES THEREFOR
"
PROVISIONAL SPECIFICATION left by the said Joseph Rogers at the Office
of the Commissioners of Patents on the 30th October 1883.
JOSEPH ROGERS of N° 16 Hanover Squaro in the County of Middlesex
"IMPROVEMENTS IN SIGNAL AND OTHER LAMPS AND LANTERNS AND IN LENSES
THEREFOR
"
One part of my present invention has reference to a construction of lenses for which
Letters Patent N° 1035 dated 26th February 1883 were granted to me, wherein a
disc or layer of colored glass was fitted between two lenses or parts of a lense in
order to produce a more brilliant colored light than is possible with the ordinary
lenses of colored glass. In adapting this system to railway signals in which
differently colored discs of glass are mounted on a moveable arm or frame so as to
be brought alternately in front of the lens of the lamp, I, according to my present
improvements, either arrange such discs to move up and down between the two
lenses of white glass of the signal lamp, or I fix the one lens of white glass in the
frame carrying the colored glass disc or discs, by preference in front of such disc,
there being of course one such lens to each disc of colored glass. These lenses, as
also the colored glass discs, would have to be made of somewhat oval or oblong
shape, in order to allow for inaccuracies in the movement of the arm carrying the
same. Or, in place of providing a separate sheet or disc of colored glass in the
moveable arm, the lens may be coated or flashed with colored glass.
According to another part of my invention, I produce a greatly increased
illuminating power in a lamp or lantern, by providing the same with two plano
convex lenses arranged a short distance from each other in front of the source of
light, the convex surface of each lens being directed outwards and the curvature
of the convex surface of each lens being by preference formed with a radius
corresponding to the distance of the said lens from the source of light, or nearly so,
that is to say, both lenses are so proportioned as to have approximately a common

page_text: focus in which the source of light is situated. By preference the outer lens in
addition to being formed with a greater radius, is also made of a proportionately
larger size than the inner lens, so that the diverging rays passing through the
latter are all, or nearly all, caught by the outer lens. Such improved construction
of lamps or lanterns may be employed not only for signalling purposes, but also
for illuminating lighthouses, and for general purposes of illumination. In the
latter case there may bo several sets of such double lenses arranged on several sides
of the source of light, as also above and below the same.
In applying this arrangement to signalling with moveable colored glass discs as
first above referred to, the frame with the colored disc may be arranged to move
to and fro either behind, in front of, or between the two lenses, or, as in the first
described arrangement, the one lens may be carried by and move with the frame of
the colored disc, or the lens may be flashed or coated with colored glass.
Although a much better effect will be produced by constructing the two lenses as
above described, yet a certain advantage will also be gained if the lenses are
otherwise formed, and in some cases, the one lens may be a double convex lens or
a concavo convex or mensicus lens, instead of plano convex,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Joseph Rogers in the Patent Office on the 29th April 1884.
JOSEPH ROGERS of N° 16 Hanover Square, in the county of Middlesex.
"IMPROVEMENTS IN SIGNAL AND OTHER LAMPS AND LANTERNS AND IN LENSES
THEREFOR
"
One part of my invention has reference to a construction of lenses for which
Letters Patent No 1035, dated 26th February 1883 were granted to me, wherein a
disc or layer of colored glass was fitted between two lenses or parts of a lens, in
order to produce a more brilliant colored light than is possible with the ordinary
lenses of colored glass.
In adapting this system to railway signals in which differently discs of glass are
mounted on a moveable arm or fraine; so as to be brought alternately in front of
the lens of the lamp, I, according to my present improvements, either arrange such
discs to up and down between the two lenses of white glass of the signal lamp or
I fix the one lens of white glass in the frame carrying the colored glass disc or
discs by preference in front of such disc, there being of course, one such lens to each
disc of colored glass. These lenses, as also the colored glass discs may be made of a
somewhat oval or oblong shape, in order to allow for inaccuracies in the movement
of the arm carrying the same.
Or, in place of providing a separate sheet or disc of colored glass in the moveable
arm, one of the lenses may be coated or flashed with colored glass.
According to another part of my invention, I produce a greatly increased
illuminating power in a lamp or lantern by providing the same with two plano-
convex lenses arranged a short distance from each other in front of the source of
light, the convex surface of each lens being directed outwards, and the curvature
of the convex surface of each lens being by preference formed with a radius
corresponding to the distance of the said lens from the source of light, or nearly so,
that is to say, both lenses are so proportioned as to have approximately a common
focus in which the source of light is situated. By preference, the outer lens, in
addition to being formed with a greater radius is also made of a proportionately
larger size than the inner lens, so that the diverging rays passing through the latter
are all or nearly all caught by the outer lens. Such improved construction of
lamps or lanterns may be employed not only for signalling purposes, but also for
illuminating lighthouses. and for general purposes of illumination. In the latter
case there may be several sets of such double lenses arranged on several sides
of the source of light, as also above and below the same. In applying this
arrangement to lamps such as are used on trains, at sea, or for other purposes,
where different colored lights aro required, discs or layers of colored glass are
inserted between the two lenses, the front lens being enclosed in a circular frame
attached to the front part of the Lamp by a hinge and fastening.
In applying this arrangement to signalling with moveable colored glass discs as
first above referred to, the frame with the colored discs may be arranged to move
to and fro either behind, in front of or between the two lenses, or, as in the first
described arrangement, the one lens may be carried by and move with the frame
of the colored disc, or the lens may be flashed or coated with colored glass.
Although a much better effect will be produced by constructing the two lenses
as above described, yet a certain advantage will also be gained if the lenses are
otherwise formed and, in some cases, the lens may be a double convex lens or a
concavo-convex, or meniscus lens, instead of plano-convex.
Fig 1 of the accompanying drawings shews the arrangement of signal lamps first
above described, wherein the colored glass semaphore discs a and b are arranged to

page_text: move up and down between the lens c fixed in the lamp and the second lens d
carried by an arm e, fixed to the lamp or the bracket carrying the same. Fig. 2
shews the arrangement in which the colored glass discs a b have each a lens å in
front of them in the semaphore arm; or in place of a separate colored disc, tho
inner surface of the lens d can be flashed or coated with colored glass..
Fig. 3 shews the arrangement of two plano-convex lenses f g situated a short
distance from each other, the curvature of the convex surfaces of both lenses
having approximately the same focus, in which is placed the source of light h, the
outer lens being made of proportionally larger diameter than the inner one, so
that the diverging rays of light from the inner lens shall all or nearly all be caught
by the outer one.
Having thus described the nature of my invention and in what manner the
same is to be performed, I claim :-
-
First: Constructing signal lamps with two lenses, between which the frame or
arm with the colored glass is made to move up and down, substantially as herein.
describod.
Second: The use of lenses in combination with the colored glasses that are
moved to and fro in front of signal lamps, so that the light from the signal lamp
passes both through the colored glass and the lens in connection therewith,
substantially as herein described.
Third: The use, of lenses flashed with colored glass mounted in a frame and
moved to an fro in front of a lamp for signalling purposes, substantially as herein
described.
Fourth: The use, in combination with signal and other lamps, or lanterns, of two
plano-convex lenses, arranged in front of each other and having a common focus
or approximately so, in which the, source of light is situated, substantially as herein
described.
In Witness. whereof, I the said Joseph Rogers have hereunto set my hand and
Beal this twentyfifth day of April in the year of our Lord, one, thousand eight
hundred and eighty-four.
TOSEDIT PACEDO