Improvements in Signalling on Railways, and Means therefor.
Year: 1894

page_text: .
Date of Application, 22nd May, 1894
Complete Specification Left, 9th Jan., 1895-4ccepted, 18th May, 1895
PROVISIONAL SPECIFICATION.
Improvements in Signalling on Railways, and Means therefor.
We. THE AUTOMATIC ELECTRIC RAILWAY SIGNAL COMPANY, LIMITED,
of 11 Rumford Place, Liverpool, in the County of Lancaster, EDWIN BLAKEY,
of 21, Tanfield Chambers, Bradford, in the County of York, Electrical Engineer,
and JOHN PATRICK O'DONNELL, of 71 Palace Chambers, Westminster, in the
County of London, Engineer, do hereby declare the nature of this invention to be
as follows:-
This invention relates to improvements in signalling on railways, and means
therefor, and is designed to be employed in conjunction with the ordinary single
needle block system at present in use on railways, or with any permanent current
block system.
In the ordinary single needle block system, owing to the instruments being
entirely under the control of the signalmen, serious accidents occur through
carelessness in operating the instruments. It is therefore the object of the present
invention to provide against such carelessness and thereby to afford increased safety
in railway travelling.
For this purpose, we employ, in addition to the ordinary electrical arrangement
of the single-needle block, or other, system, electrical circuits provided with relays
and having a series of contact devices adapted to be actuated by the train, the
arrangement being such that a train, on entering a section, will automatically place
the signal controlling that section at "danger," and the signalman at the commencement
of such section will be prevented from clearing the signal until the train has passed
out of the section, and he has received the "line clear" signal from the signalman
in advance. The arrangement, moreover, is such that, should the signalman at the
beginning of any particular section neglect to give the signal "train on line " to the
next cabin, the train will automatically give this signal by actuating a suitable
contact device and closing a relay which cuts out the ordinary signal batteries and
brings in another and preferably a more powerful battery, and will, in any case, lock
the instruments in both cabins at "train on line." The train when nearing the end
of the section again unlocks the needles by operating another contact device, and,
in some cases, this latter contact device may be arranged to also control one of the
circuits of the next section, in place of one of the contact devices which would
otherwise be employed in it.
The semaphores or signal arms, which are under electrical control, and are all
arranged so that they fall to "danger" by gravity, cannot be cleared by the
signalman so long as the train remains on the particular section which each signal
respectively controls.
The said semaphores or signal: arms may be operated electrically, or mechanically,
and each is controlled by means of a contact key which, on being operated by the
signalman, serves, if the signal is worked electrically, to complete the signal circuit
and clear the signal when, but not until, certain relays controlled two of the
said contact devices are closed, and a polarized relay, arranged to be actuated
by the block instrument, has also been operated. If the signal is worked
mechanically, the said contact key is arranged to control any suitable construction
of locking or slot apparatus; and this key may be so constructed as to control two

page_text: or more signals, say, for instance, "home"
separately.
Dated this 22nd day of May.1894.
and «.
distant," either together or
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 6, Victoria Street, Nottingham,
Agent for the Applicants.
improvements in Signalling on Railways, and Means therefor.
We, THE AUTOMATIC ELECTRIC RAILWAY SIGNAL COMPANY, LIMITED,
of 11 Rumford Place, Liverpool, in the County of Lancaster, EDWIN BLAKEY,
late of 21 Tanfield Chambers, but now of 18 Horton Road, Bradford, in the
County of York, Electrical Engineer, and JOHN PATRICK O'DONNELL, of
71, Palace Chambers, Westminster, in the County of Loudon, 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,
reference being had to the accompanying drawings and to the letters and figures
marked thereon, that is to say :-
This invention relates to improvements in signalling on railways, and means
therefor, and is designed to be employed in conjunction with the ordinary single
needle block system at present in use on railways, or with any permanent current
block system.
In the improved system of block signalling, about to be described, the block
regulations remain unaltered, the said single needle instrument is retained
substantially unaltered, and has no mechanical connections (as is usual in other
forms of lock and block systems) with the levers of the interlocking apparatus.
In the ordinary single needle block system, owing to the instruments being
entirely under the control of the signalmen, serious accidents occur through
carelessness in operating the instruments. It is therefore the object of the present
invention to provide against such carelessness, and thereby to afford increased
safety in railway travelling.
"
For this purpose, we employ, in addition to the ordinary electrical arrangement
of the single needle, or other block system, electrical circuits provided with
relays and having a series of contact devices adapted to be actuated by the train,
the arrangement being such that a train on entering a section will automatically
place the signal controlling that section at "danger," and the signalman, at the
commencement of the section, will be prevented from clearing the signal until
the train has passed out of the section, and he has received the "line clear'
signal from the signalman in the next cabin. The arrangement, moreover, is
such that, should the signalman at the beginning of any particular section neglect
to give the signal "train on line" to the next cabin, the train will automatically
give this signal by actuating a suitable contact device and closing a relay which
cuts out the signal batteries and brings in a more powerful battery, and will, in
any case, lock the instruments in both cabins at "train on line."
The train, when passing out of the section, again unlocks the needles by operating
another contact device.
The semaphores or signal arms which are under electrical control, and are all
arranged so that they move to "danger" by gravity, cannot be cleared by the
signalman so long as the train remains on the particular section which each signal
respectively controls.
For the purposes of this description, the signal is worked mechanically, and a
5

page_text: "
contact key is arranged to control any suitable electric slot or signal replacer, and
this key may be so, constructed as to control two or more signals, say for instance
"home
and "distant," provided an electric slot is fixed on each of the said
Our invention will be readily understood by reference to the accompanying
drawings, in which :
.signals.
Fig. 1 shows, diagrammatically, our improved system of electric signalling for use
on railways.
Figs. 2 and 3 show interior views for the transmitting and receiving single needle
instruments we find it advantageous to employ, ouly so much of the instruments
being shown as is required to illustrate the connections.
Fig. 4 is a diagram illustrating the arrangement of the "sections" of the line.
A and B represent signal cabins situated respectively at the commencement and
at the end of a section. C, C, represent the rails in the section, of which only a
single set is shown, and D represents the starting or other signal by which the
section is controlled. It is to be understood from Fig. 4. that what is meant by
the word "section" is the portion of line comprised between one starting signal
and the next starting signal, there being thus two sections shown in Fig. 4.
D', D, are respectively the "distant" and "home" signals of each section.
a is a single needle block instrument situated in the cabin A, and actuated in the
ordinary manner by a battery a¹ and a current reverser a³, the internal arrangement
of the instrument a and its connections being more clearly shown in Fig. 2. To
prevent the signalman at cabin A operating his signal to the safety attitude by
giving "line clear" to himself, a spring a³ is provided which bridges the gap
between two bars a*, one on each side of the instrument. This spring, through
which the current for actuating the signal passes, is adapted to be raised by a
cam or projection.a on the axle d' of the reverser a², so as to interrupt the circuit i
to the signal when the reversing handle is put to "line clear." is a similar
instrument to a, situated in the cabin B, and actuated by a battery, and a
current reverser b³. The connections of this instrument are shown in Fig. 3.
The two instruments serve for the section of line between the two cabins, and it is
to be understood that each section of the line is similarly controlled. c, d, e, and f, are
four contact devices adapted to be operated by the train in passing along the
section. The contacts which we find it advantageous to employ are those described
in the Specification of British Letters Patent No. 13,77887. We also find it
advantageous to actuate the said contacts by means of the depressible rail described
in the Specification of British Letters Patent No. 12,985". The contact.
devices c and e, when depressed by the train, are arranged to interrupt the circuits
in which they are situated, while, on the other hand, the contacts d, and, are
arranged, when so depressed, to complete their circuits.
с
9,
The signal D, for the set of rails shown, is controlled or operated by a circuit
the apparatus for effecting such control being preferably the electrical_signal
replacer or "slot" apparatus described in the Specification of British Letters
Patent No. 12,575. The circuit g is termed the local circuit, and is controlled by
a relay . The magnet of this relay is included in a circuit i, termed the signal
circuit, which can be closed by the signalinan, by means of a key i, which, after
being pressed against a contact j', is kept closed by the action of a magnet *
included in the same circuit. The completion of the signal circuit i depends further
on the closing of two other relays k and 1, the latter being polarized. The former
relay & is situated in a circuit k termed the main circuit, controlled by the contact.
devices c and and containing, near the end of the section, a relay whose tongue
or armature, when attracted, completes a branch leading to earth, and keeps
this magnet energised after the contact device has resumed its normal position.
On the opening of the line, the armature of this relay is first closed by hand,
but afterwards, in the working of the line, the trains themselves effect this closing
automatically in leaving the section.
The polarized relay is included in the circuit m of the single needle"

page_text: This
instruments α, b, and is arranged so that it only completes the signal circuit i when
the signal line clear" has been sent through the single needle circuit m.
circuit m also passes through contacts on a relay n whose tongue or armature n¹
carries two insulated contact plates n³, and whose magnet is in a circuit. 0, controlled
by the two contact devices d and e. The purpose of this relay is to cut out, at the
proper time, the batteries a¹ and 6' and to bring another and preferably stronger
battery p into the single needle circuit m, and vice versa.
The working is as follows:-
"
Prior to a train approaching, the section, which it does in the direction of the
arrow, the parts are in the positions shown in Fig. 1, the relays kand having
been energised by a preceding train, as will be hereinafter described, and their
tongues being held or attracted The circuit is thus completed and attracts the
tongue or armature of the relay k. On the signalman at B sending the "line
clear signal to A, current will flow from the reverser through the portion of the
circuit m leading to the contacts of the relay n, to the upper contact n³, of this
relay, back to the coils of the instrument at B3, thence through the line circuit m to
the reverser a³, and from this reverser through the coils of the instrument a, to the
coils of the polarized relay (Fig. 1) and to earth, and back by the earth
connection of the reverser to the battery b¹. In passing through the polarised
relay, the tongue of the latter is drawn over into the position shown in dotted
lines, so completing the circuit i, save for the break at the contact j¹.
66'
"
So
When the signalman at A wishes to lower the signal at D, he depresses the key j,
so completing the contact, and the circuit i, energising the relay h, and causing
its tongue to close and complete the local circuit g, and permitting the signal to be
operated. The train is thus admitted to the section, and on passing the first
contact device c, it interrupts the main circuit ', and causes the tongues or
armatures of the relays and in that circuit to open. The former of these
interrupts the signal circuit i, releases the key, and thereby demagnetises the
relay h, interrupts the local circuit g, and causes the signal to go, by gravity, to
"danger.' The signalman at A cannot then lower the signal until the train has
passed the last contact /. When the train reaches the contact d, it depresses it,
and momentarily completes the circuit o, energises the magnet of the relay n, and
draws down the tongue n', thereby completing the branch circuit o' to earth, which
keeps the relay magnet energised until the train passes the third contact e.
long as the tongue remains in the position shown, the battery p, only, is in the
single needle circuit m, and keeps the needles locked at "train on line," so that in
case the signalman at A should have forgotten to send this signal to B, the train
will thus da it automatically. The current from the battery » passes through
earth to the polarised relay, thence through the wire m to the instrument at a,
next to the reverser a², thence to the reverser 6, the coils of the instrument b, the
lower plate n² of the tongue of the relay n, and finally back to the battery p.
This battery is, by preference, stronger than the batteries at a and b¹.
As soon
as the train passes the third contact e, however, the circuit is interrupted
momentarily and the tongue n¹ of the relay n rises, the battery.p is cut out of the
single needle circuit m, and the instruments at A and B are unlocked and assume
the "line blocked" position (provided the signalman has placed his handle to the
normal position) ready for the signalman at B to send such signals to A as may
be necessary.
The contact device d, by reversing the polarised relay 1, will also cause the signal
circuit to be broken and the signal D to go to "danger" should the first contact
device "", from any reason, have failed to act.
A's the train passes the last contact f, it depresses it, and thereby remakes the
main circuit, and re-energises the relays and k². As already stated, the tongue
of the latter completes a branch circuit ka by which its magnet is kept energised
after the contact has resumed its normal position. The closing of the other
relay k puts the signal circuit in a state ready for completion, by means of the
key, after the sending of the signal "line clear" has closed the relay l.
"

page_text: 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 improvements in signalling on railways, whereby a train, on entering a
section will automatically place the signal controlling that section at "danger" and
prevent the lowering thereof until it has passed out of the section and will also
automatically place the needles in the cabins at "train on line," holding them in
that position, and releasing them prior to leaving the section, so that the signalman
at the commencement of the section will be prevented from lowering the signal
until the train has actually left that section and the signal "line clear" has been
given by the signalman at the other end, substantially as described.
2. The improved system of block signalling on railways, in which the single
needle instrument is retained unaltered, the block regulations remain unaltered,
and the single needle instrument has no mechanical connections (such as are usual
with other forms of lock and block systems) with the levers of the interlocking
apparatus, substantially as described.
3. In a lock and block system for signalling on railways, retaining the single-needle
instrument substantially unaltered, and without mechanical attachments, as the
essential feature of the system, substantially in the manner and for the purposes
herein set forth, and as illustrated on the accompanying drawings.
4. In a system of signalling on railways, as above claimed, the means for
carrying out the same, consisting in the combination, with the single needle
instruments a and b, of a main circuit k, a contact breaker c in said circuit (operated
by the passing train), a signal circuit i controlled by a relay k situated at or near
the commencement of the section and containing the key for controlling the
signal, a polarised relay in the circuit m of the single needle instruments, also
controlling the signal circuit, a local circuit g including the signal and controlled
by a relay h, a battery p for holding the signal instruments at "train on line," a
relay n for putting this battery in and out of the single needle circuit m, a battery
with a circuit maker d and a circuit breaker e (operated by the passing train) for
controlling such relay n, a branch circuit o' to earth, to keep the relay closed, and
a circuit maker f (operated by the train) at the end of the section to energise a
second relay in the main circuit k¹, and cause it to close its earth connection k³,
substantially as described and shown in the drawings.
5. Our improvements in signalling on railways and the means therefor,
substantially as hereinbefore described and illustrated in the accompanying
drawings.
DL of In 1905