IMPROVEMENTS. IN SIGNAL LAMPS
Year: 1854

page_text: LETTERS PATENT to William Vitruvius Greenwood and John Saxby, of
Brighton, Engineers, for the Invention of "IMPROVEMENTS. IN SIGNAL
LAMPS."
Sealed the 18th February 1855, and dated the 19th August 1854.
PROVISIONAL SPECIFICATION left by the said William Vitruvius Green-
wood and John Saxby at the Office of the Commissioners of Patents,
with their Petition, on the 19th August 1854.
We, WILLIAM VITRUVIUS GREENWOOD and JOHN SAXBY, of Brighton,
Engineers, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN SIGNAL LAMPS " to be as follows:-
Our improvements in signal lamps for railways consist in making one lamp
double-acting, so as to throw different coloured rays of light up and down the
line. For example, a green light may be shown upon the "up" line of rail,
and a red light to the "down" line, that is to say, the portions of the lines on
either side of the signal lamp. The following is a description of the apparatus
employed: The outer casing of the lamp is a cylinder of iron, partly open at
the top, and perforated with holes at the bottom for the admission of air to the
flame of the lamp or gaslight; a hollow iron rod or tube supported by a circular
bracket, in which it rotates freely, is carried through the inner casing of the.
lamp, and fixed to a metallic frame, to which it gives motion. Within the rod
just referred to is another tube, supported by a bracket below the other, and.

page_text: this is likewise secured to a metallic frame arranged concentrically within
the other; a handle is fitted to each of the tubes, so that the frames may
be moved either together or independent of each other. At each side of
the outer casing is fitted an ordinary bull's-eye lens, and at each side of the
concentric frames are fitted two strips of ordinary coloured glass. Within
the opening left in the top of the outer casing a lamp is fitted, the flame
of which is opposite-the-lenses in the side of the casing, or if gas is used
the jet must be in the same position, the gas passing through the inner tube
before referred to. When in action, either of the coloured glasses may be
brought before the flame, so as to show one colour up the line and another
down, by turning the handle connected with the rod; by turning the other
handle the colours may be instantly reversed, and the signals "danger" or
"all clear" given, as required. By this arrangement one lamp performs the
office of two or more, as heretofore, and strips of ordinary stained glass being
used for the coloured light, the expense of stained lenses is obviated. On each
of the circular brackets. are three, studs, which fit a slot cut in each of the
handles; the stud retains the handle in its place when a signal is made, and
indicates at once the position the handle should be in to make a certain signal;
thus the right hand may be red, the left green, and the centre white.. The
above is an outline of our Invention, the details of which we reserve a right to
modify as required
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Vitruvius Greenwood and John Saxby in the
Great Seal Patent Office on the 19th February 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
VITRUVIUS GREENWOOD and JOHN SAXBY, of Brighton, Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of August, in the year of our Lord
One thousand eight. hundred and fifty-four, in the eighteenth year. of Her.
reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said William Vitruvius Greenwood and John Saxby, Her special licence
that we, the said William Vitruvius Greenwood and John Saxby, our exe-
cutors, administrators, and assigns, or such others as we, the said William
Vitruvius Greenwood and John Saxby, our executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term, therein expressed, should and

page_text: lawfully might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN SIGNAL LAMPS," upon the condition (amongst others)
that we, the said William Vitruvius Greenwood and John Saxby, by an
instrument in writing under our hand and seal; should particularly describe
and ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that we, the said William Vitruvius Greenwood &
John Saxby, do hereby declare the nature of our 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 these improvements in signal lamps for railways and other
purposes where signals by means of colored lights are required, is to combine
in a single lamp the different signals required for either the "up" or "down"
line of rails; and if used on board ships, or at the entrance of docks, harbours,
&c., by these improvements one lamp only will be necessary to show a variety
of colored lights. In its external appearance the improved signal lamp docs
not materially differ from those at present in use. The outer casing of the lamp
is furnished with two ordinary lenses or bulls-eyes of uncolored glass. Within
the outer casing is a cylindrical metal frame extending above the lenses; in
this frame are fastened two pieces of colored glass, one red and the other
green, and either of these glasses may be interposed at will between the flame
of the lamp and one of the lenses, causing a green or red color to be imparted
to the lens opposite the colored glass. Within the frame before named is
placed the lamp, the outer framing of which is furnished with two pieces of
coloured glass, similar to the foregoing; these glasses are intended to be inter-
posed between the other lens and the flame of the lamp. The frame carrying.
the colored glasses and the lamp with its colored glasses are attached to two
tubes, working concentrically and carried down to a bracket below, where a
handle is secured to each tube in such manner that either tube máy be worked
independently of the other. By these means either a white, green, or red
light may be thrown either up or down the lines of railway; and if the lamp
be used for marine purposes, colored lights may be shown, as described, or
other colors introduced, if necessary.
In the Drawing accompanying this Specification the improved signal lamp
is shown in elevation and detail: Fig. 1 is a side elevation; Fig. 2, a front
elevation; and Fig. 3, a vertical section of the same. A is a
signal post
or

page_text: upright, to which is secured the bracket B, shown in plan by Fig. 4, and in
secture by Fig. 5, upon which the signal lamp C is placed; D, D; are two
lenses of uncolored glass, fitted in the outer casing E, opposite to each other,
as shown by Fig. 1. F is a cylindrical frame attached to the metal disc or
ring G. The upper ring of the frame is supported by strips of metal which
divide the circumférence into compartments; in two of these compartments
(adjoining each other) are placed two pieces of ordinary stained glass, one
red and the other green. Figs. 6, 7, represent a plan and elevation of the
frame F and disc G. The metal ring G is fastened to a tube or pipe II,
which is carried down to a bracket I; to the lower end of the tube H is
fitted a handle H, by which the tube H and ring G may be caused to rotate
when desired.
Within the frame F is placed the lamp K, which is secured to a disc or
ring K'; this disc is fastened to a tube L, which rotates freely within the tube
H; the tube L is also carried down to the bracket I, and has a handle L'
fitted to it, as seen by Fig. 1.
The bracket I consists of a double plate, as shown in the section Fig. 3.
The handle of the outer tube rests upon the upper plate, and that of the inner
tube upon the lower plate. There are three studs upon each of these plates,
and an aperture or slot is made in each of the handles, so that either of them
may be placed and retained in any one of three positions; by bringing either of
the handles over one of the studs, it is retained in that position as long as
desired.
The arrangement of this part of the apparatus is more clearly shewn by the
plan view of the bracket I, Fig. 8. When the handles are placed on the two
front studs, as shown by the full lines in the Figure), both the lenses of the
lamp above will show a white light; upon moving one or both the handles to
the centre studs, either one or both the lenses will show a green light; and when
the bandles are moved round to the studs nearest the post, a red light will be
shown. By this it will be understood that either lens may be made to show a
colored light as required, one lens being the signal light for the "up" linc, and
the other for the "down." In order that the signal man may know at once
in what position to place the handles so as to give the required signal, the
compartments around the bracket and between the handles are coloured, to
correspond with the colors of the glasses above. This arrangement of color is
indicated by the initials W, G, R, in Figs. 1, 2. Thus, when the handles are
retained by the front studs, or those over the white color, those portions of the
frame G and lamp K in which there is no glass are opposite the lenses which
consequently show a white light. Upon moving either of the handles to the

page_text: next stud, it will cause the tube and its frame to rotate, and bring the green
glass between the frame and the lens, and moving either of the handles to the
further stud will bring the red glass between the flame and the glass. Fig. 9
is a plan of the under side of the bracket I. An arrangement similar to the
foregoing, or slightly modified to suit the particular service or locality, may
be used for marine purposes, or as a hand lamp for signalling when any
obstruction occurs upon a railway line. The signal lamp arranged as herein-
before described may be used as readily with naptha or gas as oil, in the latter
case, by connecting a gas pipe to the tube L by a union joint, so as not to
interfere with its rotation, and attaching a burner to the upper end.
Having described the nature of my Invention, and the best means I am
acquainted with of carrying the same into practical effect, I wish it to be
understood that I do not confine myself to the precise arrangement of details
as herein described as shown; but what I claim and desire to secure by the
herein-before in part recited Letters Patent is, the construction and arrange-
ment of signal lamps, substantially as herein described and shown.
In witness whereof, I, the said John Saxby, have hereunto set my
hand and seal, this Sixteenth day of February, in the year of our
Lord One thousand eight hundred and fifty-five.
JOHN SAXBY. (L.B.)