IMPROVEMENTS IN RAILWAY SIGNALS
Year: 1866

page_text: LETTERS PATENT to John Alfred Warwick, of the Town and County of
Derby, Telegraph Superintendent, for the Invention of "IMPROVEMENTS
IN RAILWAY SIGNALS."
Sealed the 17th August 1866, and dated the 20th February 1866.
PROVISIONAL SPECIFICATION left by the said John Alfred Warwick
at the Office of the Commissioners of Patents, with his Petition, on
the 20th February 1866.
I, JOHN ALFRED WARWICK, of the Town and County of Derby, Telegraph
Superintendent, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN RAILWAY SIGNALS," to be as follows:-
The object of my Invention is to indicate at any desired place whether the
light of a distant semaphore or other railway signal is or is not burning.
For this purpose I use an apparatus consisting of one or more rods, bars,
plates, tubes, or blocks which herein-after, to avoid repetition and confusion,
I call the "expanding piece," and which is made of metal or material capable
of expanding under heat and of contracting when the source of heat is with-
drawn. This expanding piece. I fit or mount in a frame or support over or

page_text: near the burner of a semaphore or signal lamp in such proximity and relative
position thereto that the burner when lighted may by the heat it evolves
cause the metal or material of the expanding piece to dilate or expand
according to the well-known physical laws of expansion, and when extin-
guished or not lighted the absence or withdrawal of such heat will allow the
expanding piece. to contract, and the expansion and contraction thus produced
is caused to make and break an electric circuit and thereby produce or stop
the required signals. This may be effected as follows:-The expanding piece
is placed in or forms part of an electric circuit, the wires or conductors of
such circuit being so disposed that the circuit is interrupted or closed at the
expanding apparatus, that is to say, one wire or one end or part of the circuit
is connected with the expanding piece, while the other wire or other end or
part of the said circuit is connected with a fixed or adjustable stud, block, or
stop made of some conducting material and placed in such proximity to the
expanding piece that the latter in expanding may come into contact with this
stop. When the burner is lighted, and the heat thereof causes the expanding
piece to dilate or expand and to touch the stop, the electric circuit will be
at once completed, the current will pass, and a signal will be transmitted, of
course indicating that the lamp is burning. When the light is extinguished
the expanding piece consequently contracts, and contact is broken between it
and the stop, and it immediately results that the circuit is thereby inter-
rupted and the signal current ceases to pass. Or the arrangement may be
modified by making the stop of some non-conducting or intercepting sub-
stance, so as to form a current breaker, whereby when the expanding piece
expands it comes in contact with such current breaker and thereby interrupts,
the circuit and the signal does not pass, whereas when it contracts the circuit
is completed and the signal passes. I sometimes use a lever at any con-
venient part of the circuit to ensure the action of the apparatus; the expand-
ing piece presses against the shorter end of such lever, and a prolonged
motion is thus obtained at the opposite or long end thereof, the lever being
connected with one end or side of the interrupted circuit, and a fixed ōr
adjustible stud, block, or stop is connected with the other end or side 'thereof,
so that when the lever is acted on by the expansion or contraction of the
expanding piece the circuit will be either closed or broken. I sometimes use
an electro-magnet or coil; by means of which an armaturé or needle acted on
by the same indicates or records whether the circuit at the signal lamp is
broken or closed, the current when allowed to pass électrifying the magnet
and causing it to attract the armature or deflect the needle, and when inter

page_text: cepted allowing the magnet to release the armature or the needle in the
well-known way. A bell or acoustic signal may be acted upon by the current
to indicate the burning or extinguishing of the light; I sometimes use an
electric repeater.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Alfred Warwick in the Great Seal Patent Office on
the 20th August 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN ALFRED
WARWICK, of the Town and County of Derby, Telegraph Superintendent,
send greeting.
:
J
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of February, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Alfred Warwick, Her special licence that I, the said John
Alfred Warwick, my executors, administrators, and assigns, or such others as
I, the said John Alfred Warwick, my 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 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 "IMPROVE-
MENTS IN RAILWAY SIGNALS," upon the condition (amongst others) that I, the
said John Alfred Warwick, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals, 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 imme-
diately after the date of the said Letters Patent.
.
NOW KNOW YE, that I, the said John Alfred Warwick, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the accompanying Drawings,
and to the letters and figures marked thereon, that is to say :-
The object of my Invention is to indicate at any desired place whether the
light of a distant semaphore or other railway signal is or is not burning. For

page_text: this purpose I use an apparatus consisting of one or more rods, bars, plates,
tubes, or blocks which, to avoid repetition and confusion, I herein-after call
the expanding piece, and which is or are made of metal or other material
capable of expanding under heat and of contracting when the source of heat is
withdrawn. This expanding piece I fit or mount in a frame or support over
or near the burner of a semaphore or other signal lamp in such proximity and
relative position thereto that the burner when lighted may, by the heat it
evolves, cause the metal or material of the expanding piece to dilate or expand
according to the well-known physical laws of expansion, and when extin-
guished or not lighted the absence or withdrawal of such heat will allow the
expanding piece to contract, and the expansion and contraction thus produced
is caused to make and break an electric circuit, and thereby produce the
required indications. This may be effected as follows:-The expanding piece
is placed in or forms part of an electric circuit, the wires or conductors of
such circuit being so disposed that circuit is interrupted or closed at the
expanding apparatus; that is to say, one wire or one end or part of the circuit
is connected with the expanding piece, while the other wire or other end or
part of the said circuit is connected with a fixed or adjustable stud, block, or
stop made of some conducting material and placed in such proximity to the
expanding piece that the latter in expanding may come into contact with
this stop. When the burner is lighted and the heat thereof causes the
expanding piece to dilate or expand and to touch the stop the electric circuit
will at once be completed, the current will pass, and a signal or indication will
be transmitted, of course indicating that the lamp is burning. When the
light is extinguished the expanding piece consequently contracts and contact
is broken between it and the stop, and it immediately results that the circuit
is thereby interrupted and the aforesaid indicating or signalling current ceases
to pass; or the arrangement may be modified by making the stop of some
non conducting or intercepting substance, so as to form a current breaker,
whereby when the expanding piece expands it comes in contact with such
current breaker and thereby interrupts the circuit and the aforesaid indicating
or signallizing current does not pass, whereas when it contracts the circuit is
completed and the said signalling or indicating current passes. I sometimes use
a lever at any convenient part of the circuit to insure the action of the appa-
ratus; the expanding piece presses against the shorter end of such lever and
a prolonged, motion is thus obtained at the opposite or long end thereof, the
lever being connected with one end or side of the interrupted circuit and a
'fixed or adjustable stud, block, or stop is connected with the other end or side

page_text: lock nut G¹; the short end of the lever. D is pressed by the weight of the long
end, and also by a spring I, against one end of the tube C, so that upon the
lamp being lighted the heat of the flame: will, expand the tube C, which will
press against and move the short end of the lever, whereby a longer motion
will be given to the other end in proportion to the difference between the
length of the two ends of the lever, and contact between the long end of the
'lever and the contact piece G will be broken. The, lever and contact piece
being introduced into an electric circuit such circuit will be broken by the
expansion of the tube acting. upon the lever, as seen at; Figure 1,. and the
circuit will be closed by the contraction of the tube, which enables the long end
of the lever to fall on to the contact piece G. If the contact piece were placed
'on the opposite side of the lever. the circuit. would be broken by contraction
of the tube and closed by the expansion of the tube, or contact may be made
and broken directly from the end of the expansion piece, or other mechanical
contrivance may be used to increase the length of contact; but I prefer the
lever as shewn. In the same electric circuit.at any convenient place I fix an
electric bell or coil, or an electro-magnet, with a needle or armature, and an
'apparatus constructed and arranged according to my improvements to indicate
'whether the circuit in the apparatus in the lamp be broken or closed, or, in
other words, to indicate whether the. lamp.be burning or not. The arrange-
iment I prefer is shewn at Figures 1, 2, and 3, in which K represents a case
having a horizontal division or shelf a short distance from the bottom. This
'case may be placed in the signal box or other place where it can be readily
seen by the signal man or other required attendant. This case K has on the
under side of the shelf a bell L, and on the upper side a plate M which
supports an electro-magnet, of which N, N', are the poles, which are supported
at either end by a plate O,.which plates O are secured to projections at each end
of the plate M. Pare two set screws lying centrally and between the poles of
the magnet; these two screws P are provided with lock nuts, and these
*set screws are passed through projections P¹ on the plate M, and they support
the ends of an axle passed through and lying at right angles to an armature Q.
which has a wire. on its lower side terminating in a clapper R, and on its
upper side a wire or arm R¹ bent as required and terminating in or being
attached to a plate having the words "IN" and "OUT" upon it, which said
.words are arranged to be seen one at a time, through a hole in the centre of a
dial S, which has the word "light" upon. it on the outside above the hole
in the dial. The poles of the electro-magnet are connected by wires N2 and
N with two clamping screws at the back of the case to which other wires

page_text: N', No, are attached, the other end of the wire N* being attached to an
electric battery, from which battery a wire No is conducted; this wire N6' is
attached to the case of the lamp of the semaphore or other signal; the other
end of the wire No being attached to the bracket H of the contact piece in the
lamp. And for the purpose of breaking the circuit in the day time so as to
assist in preventing the exhaustion of the battery there is a knob having the
word or letters "ON" upon it in front of the case. This knob is secured on
the outer end of a short axle or pin T; the inner end has secured on it a
circuit-breaking piece T¹. (or piece forming a circuit breaker), the left edge
of which piece (as seen in front view at Figure 2) bears upon a flat piece
of metal T2, which has its lower end armed with a piece of platinum or other
metal, which when the index shews that the light is out, as at Figure 2, will
be held clear of another piece of metal T3 (secured to the inside of the case)
when the circuit is broken. The piece T¹ being moved into the position
shewn by the signalman or other attendant during the day time, and when
not so moved the pieces T2 and Ts form a "continuation of the wire N2 from
the electro-magnet to the clamping screw, to which is attached the wire N³,
when the circuit is broken by moving such knob, at the same time that the
piece T is kept clear of the piece T3, a rocking lever U is pressed upon the
wire R', the index shewing that the light is out; but when the knob is
placed so as to allow of contact between the pieces T¹ and T3 such lever U
will be kept clear of the wire R' by a spring V pressing upon the lower end
of the lever, thereby allowing the armature Q to fall away from the poles of
the electro-magnet, the armature being assisted so to fall by a spring W
screwed to a projection on the plate M, the index occupying the position
shewn by the dotted lines X, and marking the light to be out. The clapper R
of the bell stands some way from the bell ready to strike it when the electro-
magnet draws the armature opposite or nearly so to the poles.
By the above arrangement of apparatus when the circuit is broken by the
expansion of the tube the armature will fall back and carry the index "IN"
opposite the hole in the dial; but when the circuit is made by the contraction
of the tube, caused by the lamp being extinguished, the electro-magnet will
draw the armature opposite to the poles, or nearly so, the clapper will strike
the bell, and the index "OUT" will appear through the hole in the dial,
thereby calling the attention of the signalman or other attendant to the fact.
Having now described the nature of the said Invention, and in what
manner the same may be performed, I declare that I claim,—
First, arranging and combining apparatus for the purpose of indicating

page_text: whether the light of a semaphore or other railway signal is or is not burning,
such purpose being effected by means of a piece or pieces expanded by the heat
of the light when lighted, and contracted when the light is extinguished or not.
lighted, substantially as described.
Second; arranging and combining apparatus substantially in the manner
and for the purpose described.
In witness whereof, I; the said John Alfred Warwick, have hereunto
set my hand and seal, this Seventeenth day of August, in the year of our
Lord One thousand eight hundred and sixty-six.
Witness,
GEO. JON. ROBINSON,
Patent Office,
Nottingham.
JOHN ALFRED WARWICK. (L.S.)