IMPROVEMENTS IN SIGNAL LAMPS
Year: 1857

page_text: LETTERS PATENT to William Hart, of Brigg, in the County of Lincoln,
Lamp Manufacturer, for the Invention of "IMPROVEMENTS IN SIGNAL
LAMPS."
Sealed the 10th November 1857, and dated the 27th May 1857.
PROVISIONAL SPECIFICATION left by the said William Hart at the
Office of the Commissioners of Patents, with his Petition, on the 27th
May 1857.
I, WILLIAM HART, of Brigg, in the County of Lincoln, Lamp Manufac-
turer, do hereby declare the nature of my said Invention for "IMPROVEMENTS
IN SIGNAL LAMPS," to be as follows:-
This Invention relates more particularly to railway hand signal lamps, and
consists in adapting thereto a moveable slide, divided into two portions,
supplied respectively with a ruby and a green glass, which, being moved
between the light and the lense, produce either of the coloured signals which
it may be requisite to shew.
This slide works in suitable guides, and is connected to an arm worked by
a spring lever outside the lamp, such spring lever being fitted with a projecting
stud or button, which is dropped into any one of three notches or holes made
in a segment plate on the side of the lamp. By thus partially turning the
spring lever and adjusting the button accordingly, a white, green, or red light
will be shewn, the white light being exhibited when the slide is brought from

page_text: between the light and the lense. The mode of adjusting the slide may be
modified or effected in various ways, and the same arrangements are obviously
applicable to all lamps where the lights are desired to be of different colors
for different signalling purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Hart in the Great Seal Patent Office on the 26th
November 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HART, of Brigg, in the County of Lincoln, Lamp Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of May, in the year of our
Lord One thousand eight hundred and fifty-seven, in the twentieth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said William Hart, Her special license that I, the said William Hart, my
executors, administrators, and assigns, or such others as I, the said William
Hart, my executors, administrators, or 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 lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN SIGNAL LAMPS,"
upon the condition (amongst others) that I, the said William Hart, by an
instrument in writing under my 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 I, the said William Hart, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying Drawings, and to the
letters or figures marked thereon, that is to say :-
My said Invention relates more particularly to railway hand signal lamps,
and consists in adapting thereto a moveable slide, divided into two portions,
supplied respectively with a ruby and a green glass, which, being moved
between the light and the lense, produce either of the colored signals which it
may be requisite to shew. This slide works in suitable guides, and is con-

page_text: nected to an arm worked by a spring lever outside the lamp, such spring
lever being fitted with a projecting stud or button, which is dropped into any
one of three notches or holes made in a segment plate fixed on the side of the
lamp.
By thus partially turning the spring lever and adjusting the button ac-
cordingly, a white, green, or red light will be shewn, the white light being
exhibited when the slide is brought from between the light and the lense.
And in order that my said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the Sheet of Drawings hereunto annexed,
the same letters of reference indicating corresponding parts throughout all the
Figures.
Figure 1 of the accompanying Sheet of Drawings represents a side elevation
of an ordinary hand signal lamp fitted with my improvements, a portion of the
side being broken away to shew the internal arrangement of the lamp;
Figure 2 is a partial section of the same, looking from the back towards the
interior of the front side of the lamp; and Figure 3 is a horizontal section of the
same, taken through the centre of the lense or "bull's eye." A is the body
of the lamp; and B, the ordinary lense or "bull's eye," fitted into the front side
of the lamp. Immediately behind the bull's eye, and in the interior of the
lamp, is placed a slide C, capable of sliding vertically between the guides D, D,
fixed to the inside of the front of the lamp. This slide consists of a plate
having two circular openings a and b made therein, covered respectively with a
green and ruby colored glass, as shewn in the Drawings, or in place of having
a sliding plate with openings therein, the slide may consist simply of an oblong
open frame, the upper half of which contains a green and the lower half a ruby
glass. This frame is connected at its lower edge with a link E, this link being
again jointed to the lever arm F, the axis of which works in a small boss on
the side of the lamp. A spring lever G is attached to the axis of the lever F
and works outside the lamp along a segment plate H attached thereto, as
shewn in Figure 1. A small button or pin 9, in the end of the spring lever,
traverses along the segment H, and is dropped into one or the other of three
holes or notches h made therein.
"
The Drawing represents the lamp as shewing the white light or "all clear'
signal, the colored slide being below the "bull's eye," but by simply bringing
the button of the spring lever G round to the central hole or notch in the
segment, the slide will be sufficiently elevated to bring the green glass behind
the bull's eye, that is, between it and the light, whereupon a green light or
"caution" signal will be shewn.

page_text: By moving the button g to the farthest hole or notch in the segment, the
slide will be still further elevated, and the ruby glass being thereby interposed
between the light and the bull's eye, the "danger" signal will be shewn ; as
the colored glasses when not in use are always below the flame, they are not
so liable to become discolored by the smoke as when they are contained in the
upper portion of the lamp.
I may here observe, that although I have described the colored slide as
being applied more particularly to hand lamps, yet it is obvious that this slide
is equally applicable to all lamps when the lights are required to be of different
colors for different signaling purposes. And although I have described and
illustrated a particular mode of adjusting the slide, yet I wish it to be under-
stood, that I do not confine or restrict myself to that particular mode, as it
will be obvious that the adjustment of the slide may be accomplished in various
ways.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be made therefrom without
deviating from the principles or main features of my said Invention; but what
I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent, is,-
First, the general construction, arrangement, and mode of working or
adjusting the slides of signal lamps, as herein-before described.
Second, the application and use to and in hand signal lamps of slides, fitted
with colored glasses, whereby various signals can be readily given with one
lamp by suitably adjusting the slides.
In witness whereof, I, the said William Hart, have hereunto set my
hand and seal, the Twenty-third day of November, One thousand
eight hundred and fifty-seven.
WILLIAM HART. (L.8.)