Improvements in Railway Signalling Apparatus.
Year: 1889

page_text: Date of Application, 22nd Nov., 1889
Complete Specification Left, 30th Jan., 1890-Accepted, 8th -Mar.; 1890
PROVISIONAL SPECIFICATION.
Improvements in Railway Signalling Apparatus.
We, WILLIAM ANDREWS, of 116 St. Ann's Crescent, Hungerhill Road, Electrician,.
and WILLIAM HENRY PARKER, of 177, Alfreton Road, Pharmaceutical; Chemist,
both in Nottingham, in the County of Nottingham; do hereby declare the nature of
this invention to be as follows:-
Our invention relates to electrical apparatus chiefly designed for indicating upon
trains in motion the distance of another train therefrom or the position of a signal,;
but the said apparatus is also applicable for similar purposes in a signal box or other
fixed position.
:
An instrument constructed according to our invention is provided with a magnetic
needle mounted on a spindle carried in suitable bearings, and in conjunction with
the said needle are arranged wire coils similar to those of a galvanometer so that
when an electric current is caused to pass through the said coils the said needle will
be deflected.
When our indicator is to be used for indicating the position of the arm of a
semaphore signal a small semaphore arm is secured to the needle spindle and a balance
weight is also secured to the spindle to hold the said arm in a normal position
corresponding to the position of the arm of the signal proper. The magnetic needle
is so placed on the spindle that, under the action of an electric current the circuit of
which is closed by the movement of the main signal, it will move the connected-arm
to a position corresponding to that of a signal arm:
When the instrument is to be used for recording the distance of say another train
therefrom an index finger is secured to the needle spindle and arranged in conjunction
with a suitable scale of distance so that, as the resistance of the circuit in which the
instrument is placed decreases proportionately as the train nears the point from
which the current is supplied, the deflections of the finger and consequently the
distance traversed can be ascertained.
..
When applied to a train the current is advantageously transmitted through a fixed
insulated conductor by the side of the permanent way upon which a brush or roller on
the locomotive is adapted to bear.
When adapted to show the distance between two trains the distance recorder
on each engine is adapted to be placed in the circuit of a battery on the other
engine.
When the instrument is to be used for showing the position of a signal the battery
is preferably placed adjacent to the signal itself.
An electric bell or other sounding apparatus is advantageously employed in
connection with the indicator for drawing attention to the latter.
Dated the 22nd day of November 1880
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Railway Signalling Apparatus.
We, WILLIAM ANDREWS, of 116, St. Ann's Crescent, Hungerhill Road, Electrician,
and WILLIAM HENRY PARKER, of 177, Alfreton Road, Pharmaceutical Chemist,
both in Nottingham, in the county of Nottingham, do hereby declare the nature of
this invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
:
:
Our invention relates to electrical apparatus chiefly designed for indicating upon-a

page_text: train in motion the distance of another train therefrom or the position of a signal,
but the said apparatus is also applicable for similar purposes in a signal box or other
fixed position, and it comprises the improvements hereinafter described.
In the accompanying drawings,
Figure 1 is a front elevation of a distance indicator constructed according to our
invention.
Figure 2 is a view with the front removed to show the mechanism behind the same;
and
Figure 3 is a vertical section.
Figures 4, 5 and 6 are views similar to figures 1, 2 and 3 respectively of a miniature
semaphore serving to indicate the positions of signal.
Figure 7 is a diagram illustrating a suitable method of applying the distance
indicator; and
Figure 8 is a diagram illustrating the working of the miniature semaphore.
Figures 9, 10 and 11 are views similar to figures 1, 2 and 3 respectively illustrating
a modification wherein the distance indicator is provided with coils of different
resistance as hereinafter described; and
Figure 12 is a diagram illustrating the winding of the said coils.
Similar letters of reference indicate corresponding parts in all the figures.
a is the case of the instrument which is provided with a face band with a covering
glass c.
d, dare coils of insulated wire, similar to those of a galvanometer, wound upon
two hobbins of brass or other suitable material; and e is a needle or armature mounted
upon a spindle provided at its ends with needle points one of which is supported by
a screw g inside the back of the case a, and the other by a cross-bar / secured to two
pillars, which project through the face b.
jare binding screws to which the wires of the coils d, d are attached and
which serve for the connection of the circuit wires. It is obvious with this con-
struction that if an electric current be passed through the coils the armature will be
deflected more or less.
When the apparatus is for use as a distance indicator a hand or pointer k secured
to the spindle is arranged in conjunction with a scale of miles or other measure of
distance, as shown for example in figures 1 and 3. The hand or pointer is preferably
arranged so as to normally occupy a vertical position and the scale is graduated in
the same manner upon both sides of the zero point, so that the direction of the
winding of the coils or the direction of the current therethrough will not affect the
proper working of the instrument.
When the apparatus is for use as a miniature semaphore or signal indicator an
arm m is secured to the spindle as shown in figures 4, 5 and 6.
Stops n, n are provided to limit the extent of movement of the pointer k or
arm m.
وو
In the case of the miniature semaphore, a piece o of wrought iron is attached to the
centre of the needle e-at an angle thereto, as shown. The object of this piece is
twofold, that is to say, firstly it acts to counterpoise the weight of the arm m in such
a way that, when the said arın is at the "off" position, the needle e is parallel with
the coils or in a vertical position; and, secondly, when the arm is moved to the " on
or danger position as indicated by dotted lines at m¹, the piece o is acted upon
magnetically at the same time as the needle e and thus serves to increase the magnetic
pull upon the arm and so form an electrical brake for causing the arm to maintain a
rigid and immovable position when stopped by the stops n, n¹ notwithstanding the
shaking of the locomotive.
In order to use our improved apparatus it is necessary to provide an insulated and
electrical conductor or rail, such for instance as indicated at p in figures 7 and 8
extending along the line for any required distance, and to arrange on each locomotive
a brush q, or a contact-wheel, roller or the like to make permanent contact with the
said.conductor.
·
In figure 7 which illustrates the use of our apparatus as a distance indicator,

page_text: A, B indicate two locomotives, each of which is provided with an indicator, such as
shown in figures 1, 2 and 3. We arrange in connection with each instrument two
batteries, the zinc pole of one of which and the carbon pole of the other of
which are connected with some part of the locomotive so as to be in electrical con-
nection with the earth while the corresponding carbon and zinc poles respectively are
arranged in conjunction with a switch so that either can be connected with say
the terminal, the terminal ;' being connected by an insulated wire to the brush q.
Assume the battery of locomotive B and the battery of locomotive A to be
switched into circuit, as shown. While locomotive B is travelling along the portion
or section of the line beside which the conductor p is placed and no other locomotive
is running upon this portion of the line no current can pass from the battery » of the
said locomotive B as the said battery is only connected with earth at one pole.
Should, however, a second locomotive A run upon this portion of the railway, the
current of the battery of the locomotive B would flow through the contact device
the indicator and battery of locomotive A and thence to earth so that the circuit
being thus completed both instruments would be operated.
I have before referred to the use of two batteries on each locomotive. The
reason for this is that the batteries on different locomotives must work in series
and be therefore differently connected, that is to say, the carbon pole of one and
the zinc pole of the other connected to earth. It might therefore happen that two
trains would be upon the same section of line without knowing it owing to the fact
that their batteries being similarly connected opposed each other. By using two
batteries it is obvious that either battery on either locomotive can be introduced
into the circuit as required for instance, as shown in figure 7, this battery
locomotive A and the battery of locomotive B are in circuit. If, however, the
battery of locomotive A were in circuit the battery of locomotive B should
also be in circuit.
of
A locomotive driver can readily ascertain if the batteries in circuit are
opposing each other as should they be no result is shown upon the indicator..
The distance recorded upon the instruments corresponds to the resistance of the
conductor between the two points with which the brushes are on contact, and
consequently to the distance between such points, by this means the driver of the
following train is constantly kept informed of the whereabouts of the train in advance
of him and vice-versa.
It is obvious that an instrument could be arranged in a signal box so as to show
the distance of an approaching train therefrom.
The distance indicator hereinbefore described is only adapted for use with a
conducting rail p of given length. In some cases, however, it is advantageous to
adapt the instrument for use in connection with two or more rails of different
length, for instance, one of three miles, one of six miles and one of nine miles
For this purpose it is necessary to wind one of the bobbins with coils of different
gauge and consequently of different resistance, the coil of smallest gauge serving for
the shortest distance and the largest gauge for the longest distance. This arrange-
ment is shown in figures 9, 10 and 11 where we have represented one of the bobbins d
as being wound with three coils of wire of different gauge, one end of each of
which is connected to the wire on the other bobbin d, while the other ends are
respectively connected to the binding posts j, 2, 3. The winding of the coils will
be best understood by reference to the diagram figure 12.
s, figures 10 and 11 is a
switch.actuated by means of a rod t for breaking the circuit through the instrument.
Instead of or in addition to the employment of the said distance indicating
apparatus receiving and transmitting instruments for telephonic or telegraphic com-
munication may be fixed up in the signal boxes or cabins and in the guard's van so
that communication can be made from any one to any other; or from one train to
another whether in motion or stationary.
When our instrument is to be used as a miniature semaphore it is not necessary to
place the battery on the locomotive but only to place the miniature semaphore in a
circuit extending from the contact brush to the earth, as shown in figure 8, where the

page_text: terminal is connected to the insulated brush, and the other j with some part of
the locomotive through which the current can find its way to earth. In this case the
conductor is arranged in connection with a battery in the signal box, the zine
pole of which battery is connected with earth, but the circuit is only completed when
the contact brush of a locomotive is in contact with the conducting rail p.
66
"
In connection with the signal lever u is a contact piece u¹ connected with one pole
of the battery r, the other pole of which is connected to earth. The signal lever is
electrically connected with the conducting rail p so that when the said lever is in its
normal position corresponding with the "danger" or on position of the signal
as shown by the dotted lines, the circuit from the battery to the rail p is complete.
If now while the signal lever is in this position the contact brush y makes contact
with the rail p the circuit of the battery will be completed through the indicator on
the locomotive whereby the miniature arm will be moved to "danger" to correspond
with the signal. When, however, the signal lever is pulled over to the position
indicated by the full lines, to pull the signal "off" the circuit will be broken so that
the miniature arm of the indicator will drop to the "off" position.
An indicator may be fitted up in the signal box, so that the signalıman may see
whether the apparatus is in working order.
In order to enable a locomotive signal indicator to be operated from the signal box
independently of the movement of the signal lever we provide a shunt circuit v
adapted to be closed by a switch w. The advantage of this arrangement is that in
case of the signal levers becoming deranged the miniature signals of locomotives can
still be operated by closing the switch w.
In the foregoing description we bave referred to the instruments as being arranged
in a normally broken circuit but it is to be understood that they may be arranged to
work in connection with a normally closed or partially closed circuit.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:
1. A railway distance or signal indicator having a pointer or arm adapted to be
operated by a magnetic needle, arranged in conjunction with coils, substantially as
described.
2. In a distance indicator the combination of the coils d, d, the armature or needle e
mounted upon the spindle f, and carrying the hand or pointer k arranged in con-
junction with a scale of miles, substantially as described.
3. A distance indicator of the kind herein before described, one of the coils of
which is wound with wire of different gauge, substantially as, and for the purpose,
described.
4. An improved miniature semaphore for use in railway signalling, comprising a
coil or coils, and a deflecting needle fitted with an electric brake arranged in con-
nection therewith, the spindle of which needle carries the miniature arm, substantially
as described.
Dated the 30th day of January 1890
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.