IMPROVEMENTS IN RAILWAY SIGNALLING APPARATUS
Year: 1885

page_text: We, JOSEPH TOMLINSON Junior, of 64 Priory Road, West Hampstead, in the
County of Middlesex, Engineer, and AUSTIN CHAMBERS, of 214 Marylebone
Road, in the County of Middlesex, Engineer, do hereby declare the nature of
said invention for "IMPROVEMENTS IN RAILWAY SIGNALLING APPARATUS" to be as
follows:-
This invention has reference to electrical signalling apparatus for railway
signalling where the block system is employed the object being to interlock the
block and outdoor signals and make the trains themselves control the signals.
Apparatus such as hereinafter described is it will be understood designed for use
in conjunction with apparatus of that kind for operating the semaphore arms or
their equivalent in which the making and breaking of the physical connexion
between the signalman's lever or levers and the semaphore arm or its equivalent is
effected by aid of an electric current flowing in a circuit which can be completed
and interrupted as desired in such a manner that the motion of the lever or levers
may have no effect upon the arm or its equivalent, which is normally "on" or at
danger, unless the lever or levers and semaphore arm or its equivalent be connected
by the action of a second person.
When the circuit is completed the current flows, and, through the intermediary
of an electro-magnet, maintains the connection of the lever or levers and semaphore
arm or its equivalent. When the circuit is broken the current ceases, the magnet
loses its power and the working connection ceases. The mechanism by which the
physical connection and disconnection is effected may be situated near the lover or
levers or near the semaphore arm or its equivalent or at any intermediate point
between the two.
Let it be assumed there are two stations called for distinction A and B, the
direction in which trains run being from A to B.
A receiving instrument according to this invention is provided at B; in the same
electrical circuit there is an indicator at A and near A in the same circuit there is a
circuit breaker arranged to be operated by a passing engine or vehicle or train in
such manner as to break the circuit.
The receiving instrument comprises an electro-magnet in the same circuit as the
electro-magnet that maintains the connection of the lever or levers and semaphore
arm or its equivalent.
The armature of the above named electro-magnet in the receiving instrument is
carried by a spring arm or equivalent device that tends normally to assume a
position in which the armature would be beyond the influence of the magnet even
if the latter were excited. The same spring arm or equivalent device carries a
" contact
or circuit maker and breaker,-and it is operated by a pusher which if

page_text: pushed (when not locked by the means hereinafter described) will complete the
circuit through the coils of the electro-magnet and will also move the armature
into contact, with the magnet poles.
The locking device of the receiving instrument is operated by an electro-magnet
in a circuit into which is introduced near station B (but in advance thereof)
a circuit closer arranged to be operated (sos to close the circuit) by a passing
engine vehicle or train.
In practice, except at the starting station of the line, instead of using separate
circuit breakers and closers a combined circuit maker and breaker will be used, so
arranged that when operated by a passing engine vehicle or train, it will, to take
the case already assumed unlock the pusher at B, and also break the circuit
between the indicator at B and the receiving instrument and semaphore apparatus
at a third station C.
When the circuit is complete through the coils of the electromagnet of the
locking device the pusher is not locked but the locking device is itself locked so as
to be inoperative by the spring arm or equivalent that carries the armature of the
first mentioned electro-magnet of the receiving instrument. The circuit in which
are situate the coils of the electro-magnet of the locking device is broken (which is
its normal condition) and will so continue until closed (momentarily) by a passing
engine vehicle or train which will have no effect unless in the meanwhile the
pusher shall have been operated and thus shall have caused the locking device to
assume a position in which it will prevent the pusher being again operated until
after the circuit has been closed.
With apparatus as above described the modus operandi is as follows:-Let it be
assumed there is a train at A which it is desired to run to B. The signalman at A
signals to the signalman at B for permission to start the train, and the permission
is given by operating the pusher of the receiving instrument at B, which closes the
circuit through the coils of the electro-magnet that effects the physical connection
between the lever and the semaphore or its equivalent constituting the outdoor
signal at A. so that the signalman at A is enabled to lower the outdoor semaphore
or its equivalent as a signal for the train to start. As the train passes the circuit
breaker already mentioned as being near station A it momentarily breaks the
circuit so that the physical connection between the outdoor signal lever and the
semaphore arm or its equivalent at A is destroyed and the said semaphore or its
equivalent assumes the danger attitude and cannot be altered until after the
electrical circuit shall have been again closed by operating the pusher at B which
for the time being is locked. After the train has left station B it momentarily
closes the circuit through the coils of the electro-magnet of the locking device of
the receiving instrument at that station, thus unlocking the pusher of that instru-
ment Thus it will be understood that after the signalman at B has given
permission to the signalman at A to send on a train, the pusher at B cannot be
again operated to send a second permission until the circuit through the coils of
the electro-magnet of the locking device of the receiving instrument at B has been
closed by the operation of the circuit closer arranged near but in advance of that
station to be operated by the passing train.
A circuit maker and breaker is provided at each of the stations to enable either
signalman to break the circuit at will and thus put the semaphore arm or its
equivalent to "danger" before the engine vehicle or train has reached the point at
which it would break the circuit.

page_text: Improvements in Railway Signalling Apparatus.
We, JOSEPH TOMLINSON, Junior, of 64 Priory Road, Hampstead, in the County
of Middlesex, Engineer, and AUSTIN CHAMBERS, of 214 Marylebone Road, in the
County of Middlesex, Engineer, 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 :-
This invention has reference to electrical apparatus for railway signalling where
the block system is employed the object being to interlock the block and outdoor
signals and make the trains themselves control the signals. Apparatus such as
hereinafter described is it will be understood designed for use in conjunction with
apparatus of that kind for operating the semaphore arms or their equivalent in
which the making and breaking of the physical connection between the signal-
man's lever or levers and the semaphore arm or its equivalent is effected by aid of
an electric current flowing in a circuit which can be completed and interrupted as
desired in such a manner that the motion of the lever or levers may have no effect
upon the arm or its equivalent which is normally on or at danger unless the lever
or levers and semaphore arm or its equivalent be connected by the action of a
second person. When the circuit is completed the current flows and through the
intermediary of an electro-magnet maintains the connection of the lever or levers
and semaphore arm or its equivalent.
When the circuit is broken the current ceases the magnet loses its power and
the working connection ceases. The mechanism by which the physical connection
and disconnection is effected may be situated near the lever or levers or near the
semaphore arm or its equivalent or at any intermediate point between the two.
Let it be assumed there are two stations called for distinction A and B the
direction in which trains run being from A to B.
A receiving instrument according to this invention is provided at B; in the
same electrical circuit there is an indicator at A and near A in the same circuit
there is a circuit breaker arranged to be operated by a passing engine or vehicle or
train in such manner as to break the circuit.
The receiving instrument comprises an electro-magnet in the same circuit as the
electro-magnet that maintains the connection of the lever or levers and semaphore
arm or its equivalent, or the circuit of the latter electro-magnet may be a relay
circuit.
The armature of the above-named electro-magnet in the receiving instrument is
carried by a spring arm or equivalent device that tends normally to assume a
position in which the armature would be beyond the influence of the magnet even
if the latter were excited. The same spring arm or equivalent device carries a
contact or circuit maker and breaker and it is operated by a pusher which if
pushed when not locked by the means hereinafter described will complete the
circuit through the coils of the electro-magnet and will also move the armature
into contact with the magnetic poles.
The locking device of the receiving instrument is operated by an electro-magnet
in a circuit into which is introduced near. station B (but in advance thereof)

page_text: a circuit closer arranged to be operated (so as to close the circuit) by a passing
engine vehicle or train.
In practice except at the starting station of the line instead of using separate
circuit breakers and closers a combined circuit maker and breaker will be used so
arranged that when operated by a passing engine vehicle or train it will to take
the case already assumed unlock the pusher at B and also break the circuit
between the indicator at B and the receiving instrument and semaphore apparatus
at a third station C.
When the circuit is complete through the coils of the electro-magnet of the
locking device the pusher is not locked but the locking device is itself locked so as
to be inoperative by the spring arm or equivalent that carries the armature of the
first mentioned electro-magnet of the receiving instrument.
The circuit in which are situate the coils of the electro-magnet of the locking
device is broken (which is its normal condition) and will so continue until closed
(momentarily) by a passing engine vehicle or train which will have no effect unless
in the meanwhile the pusher shall have been operated and thus shall have caused
the locking device to assume a position in which it will prevent the pusher being
again operated until after the circuit has been closed. A circuit maker and
breaker is provided at each of the stations to enable either signalman to break
the circuit at will and thus put the semaphore arm or its equivalent to "danger'
before the engine vehicle or train has reached the point at which it would break
the circuit.
,,
In the accompanying sheet of illustrative drawings Fig. 1 is a front elevation,
partly in vertical section in the line x. x. Fig. 2, of a receiving instrument
according to this invention. Fig. 2 is a side elevation partly in section in the
line y. y Fig. 1 and Fig. 3 is a plan partly in horizontal section in the line 2. z
Fig. 2. Fig. 4 is a diagrammatic view illustrating an application of the invention.
Referring to Figs. 1, 2, and 3, 1 is an electro-magnet secured to a stand 2, and 3
is its armature carried by a spring arm 4 whose lower end is secured at 5. When
the armature 3 is in the position shown in full lines in Fig. 2 (which is its normal
position), it is beyond the influence of the electro-magnet 1 and would be so even
if the latter were excited as herein before stated. 6 is an adjustable screw threaded
pin carried by the spring arm 4 and serving in conjunction with a metallic
upright 7, as a contact or circuit maker and breaker. 4 is an adjustable stop for
the spring arm 4.
When the armature 3 and spring arm 4 are in the position shown in full lines
in Fig. 2 the electric circuit through the coils of the electro-magnet 1 is broken.
If however the armature and spring arm be pushed into the position shown in
dotted lines in the same Figure which can be done by forcing in the spring
pusher 8 when it is not locked as hereinafter explained, the pin 6 being brought
into contact with the upright 7 completes the circuit and the armature 3 is held in
contact with the magnet poles. 9 is an electro-magnet having its coils in the same
circuit as the electro-magnet 1; it serves to lower, when excited, a small semaphore
arm or signal 10 in a manner well understood. A similar semaphore arm or signal
in the same circuit is situate at the station in the rear of that at which the
receiving instrument is placed and serves to inform the signalman that the electric
circuit which maintains the connection of the lever or levers and semaphore arm or
its equivalent is completed and that he may then "pull off" the signal. 11 is a
circuit maker and breaker placed in the circuit of the electro-magnet 1; it consists
of two insulated plates secured to the base of the instrument and normally
connected by a metal pin or plug interposed between them as shown. By
removing this pin or plug the circuit may be broken at will.
The course of an electric current through the receiving instrument when the line
circuit 12 (Fig. 4) in which it is placed is completed is as follows:-It flows from
the terminal 13 (Fig. 3) to the upright 7, bolt 6, spring arm 4, support 4* to the
coils of the electro-magnet 1; thence it passes to the coils of the electro-magnet 9,

page_text: circuit maker and breaker 11 and terminal 14. 15 is the locking device of the
receiving instrument. In the arrangement shown it consists of a lever pivotted
at 16, and carrying at one end the armature 17 of an electro-magnet 18, whilst its
other end is provided with an extension 19. The electro-magnet 18 for operating
the locking device 15 is placed in a local independent circuit 20 (see Figs. 3 and 4)
provided with a circuit closer situated in advance of the station at which tho
receiving instrument is used and arranged to be operated, so as to close the circuit,
by a passing train or vehicle.
The operation of the receiving instrument is as follows:-When the parts are in
the relative positions shown in full lines in Fig. 2 the pusher 8 is unlocked, the
circuit of the electro-magnet 1 is open and the locking device 15 is locked in its
upper position by the spring arm 4 taking against the under surface of its
extension 19. If the pusher 8 be now pushed inwards in the direction of the
arrow in opposition to its spring it will force the spring arm 4 forward so that
the pin 6 will come into contact with the standard 7 and close the circuit of
the electro-magnet 1 and also that of the electro-magnet that effects the physical
connection between the signal lever and the semaphore arm or its equivalent at
the station to the rear of the one at which the receiving instrument is situate.
The electro-magnet 1 being then magnetised holds the armature 3 in contact with
its poles as shown in dotted lines. If the pusher 8 be now released, it will spring
outward under the action of its spring 8* as will be readily understood, and the
locking device 15 will then assume the attitude shown in dotted lines in Fig. 2.
In this position the locking device will prevent the pusher 8 being again operated
until the train or vehicle, for which the signal was permitted to be lowered by the
closing of the circuit of magnet 1, shall have passed forward to such a point as to
itself momentarily break such circuit by operating a circuit breaker and also to
operate a circuit maker for momentarily closing the circuit of the electro-magnet 18,
whereupon the armature 17 will be momentarily drawn down thus raising the
extension 19 of the locking device, whereupon the spring arm 4 will fly back so as
to again rest beneath the extension 19 and lock it as before, so that the pusher
may be again operated.
Referring to Fig. 4 A. B and C represent three stations or signal cabins.
21, 21, 21 are semaphore arms or out-door signals each placed in advance of the
cabin from which it is operated. 22, 22 are receiving instruments of the kind
herein before described with reference to Figs. 1, 2 and 3, situated at the cabins B
and C. 23, 23, 23 are small semaphore indicators that may be of the usual well
known construction, one being placed in each cabin. Each indicator 23 is placed
in the line circuit 12 which is completed through the receiving instrument at the
station or cabin in advance. 24, 24, 24 are relays of any suitable construction
operated in a manner well understood by the indicators 23 when the line circuits 12
are completed, so as to complete local relay circuits 25, in each of which is or are
situated the electro-magnet or electro-magnets for effecting physical connection of
the operating lever or levers with the semaphore arm 21. Apparatus for this latter
purpose is represented as being applied to each signal post at 26; such apparatus
may be of any suitable kind; it may be such as described in the specification of
former Letters Patent N° 6563 A.D. 1884 granted to us or of the kind described in
the specification of our application for Letters Patent No 4453 A.D. 1885. 20, 20, are
the local independent circuits of the electro-magnets 18 for operating the locking
devices 15 of the receiving instruments. 27 is a circuit breaker so arranged in
advance of the cabin A as to be operated by a passing train or vehicle and to break
the line circuit 12 between cabins A and B. 28, 28 are combined circuit breakers
and makers so arranged in advance of the cabins B and C respectively that when
operated by a passing train or vehicle they momentarily break the corresponding
line circuits 12, which are normally closed at these points, and close or complete the
local circuits 20. The circuit breaker 27 and the combined circuit breakers and
makers 28 may be of any suitable construction capable of being operated by a
passing train or vehicle.
0

page_text: With apparatus constructed and arranged as above described the modus operandi
is as follows:-Let it be assumed there is a train at A which it is desired to run
to B. The signalman at A signals to the signalman at B for permission to start
the train and the permission is given by operating the pusher 8 of the receiving
instrument at B which closes the line circuit 12 and operates the relay 24 at A so
as to close the local circuit 25 through the coils of the electro-magnet at 26 that
effects the physical connection between the lever and the semaphore arm 21 or its
equivalent, constituting the outdoor signal at A so that the signalman at A is
enabled to lower the outdoor semaphore, or its equivalent, as a signal for the train
to start. As the train passes the circuit breaker 27 it momentarily breaks the
circuit 12 and through it the local circuit 25 at station A. so that the physical
connection between the outdoor signal lever and the semaphore arm 21, or its
equivalent, at A is destroyed and the said semaphore arm, or its equivalent, assumes
the danger attitude and cannot be altered until after the electrical circuit shall
have been again closed by operating the pusher at B which for the time being is
locked. The momentary breaking of the circuit 12 by the circuit breaker 27
causes the armature 3 and spring arm 4 of the receiving instrument at B to spring
back against the extension 19 of the locking device 15 and thus opens the said
circuit 12 until it is again closed by operating the pusher 8 at B. This breaking or
opening of the circuit 12 by the circuit breaker 27 is of importance as it gives the
magnetism of the electro-magnet that effects the physical connection between the
signalman's lever and the semaphore arm 21, or its equivalent at A, time to be
destroyed and ensures that the said physical connection shall be broken and that the
signal shall assume its danger attitude.
After the train has left station B (for which permission is previously obtained
from station C) it momentarily closes the circuit 20 through the coils of the electro-
magnet 18 of the locking device 15 of the receiving instrument at B by operating
the circuit maker at 28 between B and C and thus unlocking the pusher 8 of the
receiving instrument at B. Thus it will be understood that after the signalman
at B has given permission to the signalman at A to send on a train the pusher 8
at B cannot be again operated to send a second permission until the circuit 20
through the coils of the electro-magnet 18 of the locking device 15 of the receiving
instrument at B has been closed by the operation of the circuit closer at 28 arranged
near to but in advance of that station to be operated by the passing train. The
train or vehicle after passing station B by operating the circuit breaker at 28 and
so breaking the line circuit 12 between B and C opens the circuit of the receiving
instrument at C in a similar manner to that herein before described with reference
to the one at station B. By withdrawing the plug of the circuit breaker 11 of the
receiving instrument at B the signalman thereat may break the circuit 12 after
having given permission for a train to start from A, before it has time to reach
and operate circuit breaker 27; this puts the semaphore arm 21 or its equivalent
at A again to "danger" thus stopping the train. For a similar purpose another
circuit breaker, not shown, is arranged in the circuit 12 at the station A, so as to be
under the control of the signalman there.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is
1. The method of controlling a railway signal by means of a circuit maker and
breaker placed in advance of the signal in an electrical circuit which when closed
causes the physical connection between the hand lever and the signal to be effected
and maintained, such circuit maker and breaker being caused to open and to
continue open by a temporary break in the circuit caused by a train or vehicle, and
the arrangement being such that the circuit shall remain broken so that the signal
must remain in the danger attitude until the circuit is again closed or completed by
-operating the above mentioned circuit maker and breaker situated in advance, as
above set forth.

page_text: 2. The use for the purpose referred to in the preceding claim of an instrument
comprising a circuit maker and breaker, an electro-magnet and a pusher, the
arrangement being such that when the circuit is closed by operating the pusher,
the electro-magnet will keep the circuit closed until it is broken by a circuit
breaker in another part of the circuit, and that immediately on the circuit being
so broken at a distance, it will be automatically broken also in the instrument,
substantially as described.
3. The use for the purpose referred to in Claim 1 of an instrument comprising a
circuit maker and breaker, an electro-magnet, a pusher and a locking device, the
arrangement being such that after the pusher has been operated to close the circuit
for effecting the physical connection between a hand lever and a signal, such pusher
becomes locked and cannot be again operated to close the circuit until after an
independent electric circuit has been closed by a circuit closer operated by a train
or vehicle substantially as hereinbefore described.
4. The instrument shown in and described with reference to Figures 1, 2 and 3
of the drawings for the purpose specified:
5. The general arrangement of railway signalling apparatus described with
reference to Figure 4 of the drawings whereby a temporary break in an electrical
circuit produced by a passing train or vehicle is made to cause a break in another
part of the same circuit in such a manner that the circuit shall remain broken so
that the signal cannot be lowered or returned to the safety attitude until after the
circuit has been again closed by operating a circuit closer placed in advance of the
signal and that the circuit cannot be closed or completed whilst a train or vehicle
remains on the line between the signal controlled by the said circuit and the
corresponding signal of the station in advance, as above set forth.