IMPROVEMENTS IN INDICATING THE POSITIONS OR CONDITIONS OF RAILWAY SIGNALS AND POINTS, AND IN THE APPARATUS EMPLOYED THEREIN
Year: 1863

page_text: LETTERS PATENT to Samuel Whitaker, of Craddock Street, Haverstock
Hill, in the County of Middlesex, Electrician, for the Invention of
"IMPROVEMENTS IN INDICATING THE POSITIONS OR CONDITIONS OF RAILWAY
SIGNALS AND POINTS, AND IN THE APPARATUS EMPLOYED THEREIN."
Sealed the 28th July 1863, and dated the 13th February 1863.
PROVISIONAL SPECIFICATION left by the said Samuel Whitaker at the
Office of the Commissioners of Patents, with his Petition, on the
13th February 1863.
I, SAMUEL WHITAKER, of Craddock Street, Haverstock Hill, in the County
of Middlesex, Electrician, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN INDICATING THE POSITIONS OR CONDITIONS OF RAILWAY
SIGNALS AND POINTS, AND IN THE APPARATUS EMPLOYED THEREIN," to be as
follows:-
This Invention relates to the indicating of the positions or conditions of
railway signals and points as applied to a lamp or night signal, with a view to
the indicating of the signal-man at a distance whether the lamp continues to
burn or not. It is proposed to place inside the lamp, in any position which
will insure its being heated by the same when burning, a piece of metal, of any
desired or convenient form, which will readily expand by the heat imparted to
it. The expansion or contraction of this piece of metal is made to establish an
electric contact, and complete a circuit from a battery through a galvanometer.
For example, so long as the piece of metal is expanded by the heat, the current
passes through the galvanometer, and the consequent deflection of the needle
indicates that the lamp is burning, but should the light become accidentally
or otherwise, extinguished, the cooling of the piece of metal and its contraction
[Price 8d.]

page_text: will break contact, and the circuit being interrupted, the needle will return to
its original position again, indicating to the signal man that the light is no
longer burning.
According to another part of this Invention it is proposed to connect
railway points and crossings with a battery, and with suitable contact surfaces,
so that when the point is open or closed, as the case may be, a circuit will be
established through a galvanometer, the needle of which will indicate the
position of the points in connection therewith. The same arrangement for
indicating the positions of the points is equally applicable for indicating the
position of the day signals. By providing any ordinary signal with proper
contact points, and connecting such points by wires with a battery and
galvanometer at an adjoining station or intermediate point, the setting of the
first signal is instantly indicated by the needle to the signal man of the second
signal. This arrangement is particularly applicable to the working of single
lines of railway.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Samuel Whitaker in the Great Seal Patent Office on the
13th August 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL
WHITAKER, of Craddock Street, Haverstock Hill, in the County of Middlesex,
Electrician, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of February, in the year of our
Lord One thousand eight hundred and sixty-three, in the twenty-sixth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Samuel Whitaker, Her special license, that I, the said Samuel
Whitaker, my executors, administrators, and assigns, or such others as I, the
said Samuel Whitaker, 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 "Im-
PROVEMENTS IN INDICATING THE POSITIONS OR CONDITIONS OF RAILWAY SIGNALS AND
POINTS. AND IN THE APPARATUS EMPLOYED THEREIN," upon the condition (amongst
others) that I, the said Samuel Whitaker, my executors or administrators,
by an instrument in writing under my hand and seal, or under the hand and

page_text: seal of one of them, 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 Samuel Whitaker, 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 and figures marked thereon, that is to say:-
My said Invention relates to the indicating of the positions or conditions of
railway signals and points. As applied to a lamp or night signal, with a view
to the indicating to the signal-man at a distance whether the lamp continues
to burn or not, it is proposed to place inside the lamp, in any position which
will insure its being heated by the same when burning, a piece of metal, of any
desired or convenient form, which will readily expand by the heat imparted to
it. The expansion or contraction of this piece of metal is made to establish an
electric contact, and complete a circuit from a battery through a galvanometer.
For example, so long as the piece of metal is expanded by the heat, the current
passes through the galvanometer, and the consequent deflection of the needle
indicates that the lamp is burning, but should the light become accidentally
or otherwise, extinguished, the cooling of the piece of metal and its contraction
will break contact, and the circuit being interrupted, the needle will return to
its original position again, indicating to the sigual man that the light is no
longer burning.
According to another part of this Invention it is proposed to connect
railway points and crossings with a battery, and with suitable contact surfaces,
so that when the point is open or closed, as the case may be, a circuit will be
established through a galvanometer, the needle of which will indicate the
position of the points in connection therewith.
The same arrangement for
indicating the positions of the points is equally applicable for indicating the
position of the day signals. By providing any ordinary signal with proper
contact points, and connecting such points by wires with a battery and
galvanometer at an adjoining station or intermediate point, the setting of the
first signal is instantly indicated by the needle to the signal man of the second
signal. This arrangement is particularly applicable to the working of single
lines of railway.
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

page_text: same letters of reference indicating corresponding parts in all the corresponding
Figures.
Figure 1 of the accompanying Sheet of Drawings represents the various
apparatus employed in working the day and night signals on a line of railway
in accordance with this Invention, the several electric conducting wires being
also shown in order to illustrate clearly the connections between the different
apparatus employed, so that the entire system may be more readily understood.
Of the various apparatus, A represents the indicator or galvanometer, which
may be of any well-known construction, as it constitutes separately no part of
this Invention; B is the expanding metal rod or bar, which is to be placed
inside the night signal lamp; C is a "switch" for directing the electric
current, either through the night or day signal, as may be required, which
"switch" forms separately no part of the present Invention; D represents the
arrangement of apparatus in connection with the signal rod for making and
breaking circuit, and for reversing or changing the currents from positive to
negative, and vice versa. a is the signal rod, which is made to slide vertically
in suitable guides or bearings in the usual manner, by means of a lever at any
distant signal station. To this rod is secured a horizontal arm b, which is
insulated from the rod itself, and works up and down with that rod between
fixed insulated guide bars, one of which is shown at c. The outer end of the
arm b is bent at right angles, and has a slot made therein, in which slot is
contained a small block d, which has secured to it a bow spring e, e; f is a
screw provided with a milled head, for the purpose of adjusting the position of
the block d, and causing the two ends of its spring to bear more or less firmly
against the insulated metal plates g, h, and h¹; i, i, are two pieces of ivory, or
other good insulating medium, which are interposed between the plates h, h¹,
and the ends of the middle plate g, the surface of these three plates and the
insulating pieces i, i, being level or flush, so that the ends of the spring may
slide freely along them when the signal rod is raised or lowered. The whole
of this apparatus may be enclosed for convenience of access in a box attached
to the signal post, and should be kept under lock and key. k is an electric
battery placed near the signal post, the copper or positive pole of which is
connected by the red wire with the plate h', whilst the zinc or negative
end is connected by the blue wire with the plate h. To the arm herein-
before referred to, there is fitted a spring 1, which bears against the surface of
one of the guide bars c, and in connection with this guide bar there is a wire z
(colored green), which is termed the line wire, as it passes along the line from
the signal post to the signal man's box, where it is connected with the coil of a
galvanometer A. To this coil a wire m is also connected leading to earth.

page_text: The centre cells of the battery are also connected with earth by a wire n
leading to the middle one (2) of three insulated metal plates 1, 2, and 3,
constituting the switch or reverser C of the current, which is contained, by
preference, inside the box enclosing the apparatus D. The lower plate 3 is
connected direct to earth by the wire o, and the upper plate 1 is connected
indirectly to earth by the wire p, which passes to a contact point q at one end
of the expanding bar or rod B, from the opposite end of which bar or rod
another wire r passes direct to earth; s is a metal pin or plug, which, on
being inserted into one or the other of the two holes left between the plates
1, 2, 3, will either establish a communication between the plates 1 and 2 (if
placed in the upper hole), or between the plates 2 and 3 (if placed in the
lower hole), as shown in the Drawing. The expanding rod or bar is
represented in the state it would be in when the light in the lamp is out, that
is to say, it is contracted sufficiently to cause a break in the circuit to earth,
the contact point q being out of contact with the corresponding contact
piece q on the opposite end of the bar. When using the day signal, the
expanding and contracting bar is not required, of course, and it is therefore
placed entirely out of the circuit by placing the pin or plugs in the lower
hole, as shown in the Drawing, thereby cutting off all communication with the
upper plate 1. The apparatus D in immediate connection with the signal rod
is represented as in a position indicating that the signal is not properly set, the
signal rod a being at its half stroke or traverse only, and both ends of the bow
spring e are in contact with the central insulated metal plate g, consequently
the circuit remains broken, and the needle of the galvanometer stands vertically
pointing to "signal wrong; " but if the signal rod a be elevated to the full
height, so as to bring one end of the bow spring e on to the plate k, then the
circuit is established from the zinc end of the battery through the blue wire
plate h, spring e, arm b, spring I, and guide bar c, whence it passes by the
green or line wire z to the galvanometer A, and causes the needle to deflect to
the left, pointing to "signal on." From the galvanometer the current passes
by the wire m to earth, and returns to the opposite earth wire o, passing
through the plate 3, pin or plug s, plate 2, and thence by the wire n back to
the battery, thus completing the circuit of a negative current through the
line wire and galvanometer. If the signal rod be lowered until the bow
spring e is in contact with the plate (the position assumed when the signal
is taken off), then the current passes from the copper or positive pole of the
battery by the red wire and plate through the galvanometer, causing the
needle to be deflected to the right, indicating "signal off." In effect, when
the sigual is "on," a negative current is passed through the galvanometer, and

page_text: when the signal is "off," a positive current passes through that instrument, or
vice versa, the result being the deflection of the needle to the left or right, as
the case may be. The same remarks apply precisely to the setting of the
lenses for the night signals, but when the night signal is employed, an
additional safeguard is obtained by an instantaneous indication being given if
the light should be extinguished. For this purpose it is simply requisite to
remove the pin or plug s from the lower hole, and insert it in the upper one,
thereby establishing a connection between the plates 1 and 2 of the electric
switch, and bringing the contact points q and q' of the expanding bar B into
the circuit. The current (whether positive or negative) then passes as before
through the entire combination of apparatus, but after entering the earth from
the galvanometer it returns to the battery by the earth wire r through the
expanding bar, and its contact points q, q¹, (if in contact with each other,)
thence along the wire p, plate 1, plug s, plate 2, and wire n back to
the battery, in place of passing through the earth wire o, as when using the
day signal. In all cases the battery is placed at the signal station, and not in
the signal man's box, hence the current is sent direct to the galvanometer in
the signal box from the signal post, in place of such current having first to be
sent to the signal post, and then to be returned to the signal box, as would be
the case if the battery were contained in the signal box.
Figure 2 represents a mode of applying the electric indicator to the points
or switches in the line of rails; and Figure 3 is an enlarged detail, shewing
the contact points, and their connection with the switch rail. a, a, are the
rails of a main line of railway, shewn in plan; a¹, a', are the rails of a branch
or siding, and b is the switch or point. To this switch is connected in the
ordinary manner the switch rod c, actuated from a distant station by the
handle d, rod e, and bell crank ; or it may be worked in any other suitable
manner. To some moving part near the switch b (by preference to the rod c)
is fitted an arm g insulated from the switch rod. Below the end of this arm
are placed two insulated metal plates h, h¹, a sufficient space being left
between the two plates to allow the arm g to rest between them without being
in contact with either of them. One of these plates his connected by a
wire with the positive or copper pole of a battery i (situate near the point
or switch), and the other by a wire with the negative or zinc pole of the
colored in the Drawing red and blue
same battery, the two wires being
respectively. The line wire 1 (colored green in the Drawing) is connected at
one end with the insulated arm g, and at the other with a galvanometer k
placed in the pointsman's box. A second wire m leads from the galvanometer
to earth, and the circuit is completed by the wire o leading from earth to the

page_text: battery. When the point is open, or in the position shewn in the Drawing,
the arm g rests upon the metal plate h, and a positive current passes from
the battery through the red wire, plate h, arm g, and green wire to the
galvanometer, causing the needle to indicate "point open," the current
returning to the battery through the earth and wires m, o. If the point be
shut, then the arm g slides on to the plate h¹ connected with the zinc or
negative end of the battery, and a negative current is passed through the
galvanometer, causing the needle to indicate "point shut."
If by any
derangement of the working parts the point should not be properly opened
or shut, the arm g resting midway between the two plates h, h¹, then the
circuit will be broken, and the needle of the galvanometer will assume a
vertical position, indicating "point wrong."
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 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,-
1st, the general construction, arrangement, and combination of apparatus
for indicating the positions or conditions of railway signals and points, as
herein-before described and illustrated by the Drawings.
2nd, the peculiar arrangement of electric contact surfaces, and their com-
bination with the signal rod of railway signals, in the manner and for the
purpose herein-before described and illustrated by the Drawings.
3rd, the application and use to and in signal lamps of a metal bar, which on
being expanded by the heat of the flame will make or break an electric circuit,
and so indicate whether the light is burning or has gone out, as herein-before
described.
4th, the combination of electric contact surfaces with the points or switches
of railways, and with a battery and galvanometer, in the manner and for the
purpose herein-before described.
In witness whereof, I, the said Samuel Whitaker. have hereunto set
my hand and seal, this Twelfth day of August, One thousand eight
hundred and sixty-three.
SAMUEL WHITAKER. (L.s.)