IMPROVEMENTS IN THE MODE OR METHOD OF ARRANGING AND DISPOSING THE CONNECTIONS OF ELECTRO-MAGNETIC SIG- NALLING INSTRUMENTS
Year: 1876

page_text: LETTERS PATENT to William Smith, Consulting Engineer, and Richard Robert
Harper, Electric Telegraph Engineer, both of 19, Salisbury Street, Strand,
London, for the Invention of "IMPROVEMENTS IN THE MODE OR METHOD OF
ARRANGING AND DISPOSING THE CONNECTIONS OF ELECTRO-MAGNETIC SIG-
NALLING INSTRUMENTS.”
Sealed the 16th March 1877, and dated the 20th September 1876.
PROVISIONAL SPECIFICATION left by the said William Smith and Richard
Robert Harper at the Office of the Commissioners of Patents on the 20th
September 1876.
WILLIAM SMITH, Consulting Engineer, and RICHARD ROBERT HARPER, Electric
Telegraph Engineer, both of 19, Salisbury Street, Strand, London. "IMPROVEMENTS
IN THE MODE OR METHOD OF ARRANGING AND DISPOSING THE CONNECTIONS OF
ELECTRO-MAGNETIC SIGNALLING INSTRUMENTS."
These improvements consist of an arrangement whereby errors in working the
block signalling telegraph instruments are prevented, and this arrangement is
more especially applicable to single line working of outdoor signals controlled by
electricity.
The novel arrangement of apparatus is employed for the purpose of obviating
confliction in working, as it depends upon the manner in which the instruments are
connected together either in one or more wire systems, and as in the case of the
one-wire system of working, the current having been transmitted or received in
one direction (in the case of a block signalling station), no alteration in the position
of the visual indicator of the sending portion of the indicating apparatus can be
effected until the current is sent and received in an opposite direction, thereby
preventing confliction in signalling, and rendering it impossible to admit two
trains on the same section of a single line at the same time. We effect
this by making the receiving portion of block signalling telegraphs disconnect
the battery or earth portion of the sending part of such like apparatus, as in
the absolute block working it is important that permission shall not be given
for two trains to approach each other at the same time; and we so arrange the
receiving portion of such apparatus as to enable it to be worked from the distant
D31

page_text: station to disconnect the sending portion, so that should the receiving portion be
shifted from its normal position it becomes impossible to join up the sending portion
of such apparatus, and this is effected either by relay or by insulating the stop
pins of the dials of telegraph signalling apparatus; and this Invention consists in
making and breaking the contact of the sending portion or commutator of the block
signalling telegraph instruments by a current being received through the receiving
portion of such apparatus, whereby when both sending and receiving needles of the
instruments are at or in their normal postion of, say, "blocked" either of the signal-
men of the section can work the sending portion of the instruments, and move his
index or pointer to both sides; but should the receiving portion be placed to, say,
"clear" by a signalman from a distant station the signalman is unable to transmit
a clear signal to a distant station.
To enable us to explain the utility and objects of this arrangement we propose
to describe its application to a single line worked on the block system. For this
purpose we take 3 stations, which we designate A, B, and C. The operator before
a train leaves A obtains permission from B by B placing A's indicating portion of
the apparatus to " line clear." B having given A permission A is unable to give
B permission to send a meeting train; this enables A to lower his outdoor signal,
and allow the train to enter the section between A and B. A then sends the bell
code to B to say the train has left A, and B in acknowledging his signal places
the indicating portions of the telegraph instruments to the block position, and in
so doing locks or disconnects the outdoor signal at A, and places it to "danger"; B
then calls C, and C places B signal to clear, and unlocks B's outdoor signal. The
signals at A and C being locked or disconnected in the one direction of the line,
and A, B, and C signals being locked or disconnected in the other direction of the
line, B is the only signal that can be lowered in the one direction as between B
and C.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Smith and Richard Robert Harper in the Great Seal Patent
Office on the 17th March 1877.
"
WILLIAM SMITH, Consulting Engineer, and RICHARD ROBERT HARPER, Electric
Telegraph Engineer, both of 19, Salisbury Street, Strand, London. IMPROVEMENTS
IN THE MODE OR METHOD OF ARRANGING AND DISPOSING THE CONNECTIONS OF
ELECTRO-MAGNETIC SIGNALLING INSTRUMENTS."
These improvements consist of a novel arrangement and disposition of the
connections and parts of electro-magnetic signalling instruments, whereby errors
in working electro-magnetic block signalling telegraphs are prevented; and this
arrangement is more especially applicable to single line working of outdoor signals
controlled by electricity.
The arrangement and disposition of the connections of the apparatus employed
for this purpose obviates confliction in working, as the safe working of the block
instruments depends upon the manner in which the instruments are connected
together, whether in one or more wire systems; and, as in the case of the one-
wire system of working the current having been transmitted or received in
one direction (in the case of a block signalling station), no alteration in the
position of the visual indicator of the sending portion of the indicating apparatus
can be effected until the current is sent and received in an opposite direction,
thereby preventing conflictions in signalling, and rendering it impossible for
permission to be given to admit two trains on the same section of a single line
at the same time. We effect this arrangement of the connections by making the
receiving portion of block signalling telegraphs disconnect the battery or earth
portion of the sending part of such like apparatus when worked upon the one-
wire system of block signalling, as in the absolute block working it is important

page_text: 33
that permission shall not be given for two trains to approach each other upon the
same section of the line at the same time; and we so arrange the receiving portion of
such apparatus as to enable that portion to be worked from the distant station to
disconnect or electrically break the sending portion, so that should the receiving
portion be shifted from its normal position it becomes impossible to join up the
sending portion of such apparatus to transmit a wrong signal, and this is effected
either by a relay contact maker or by insulating the stop pins of the dials of
telegraph signalling apparatus; or where the three-wire system is used we effect
the same object by blocking, "pinning," or "pegging the handle to "train on
line" or "blocked" for a train to approach a station, and thereby prevent the
receiving instrument being used to allow a second train to meet the approaching
train; and this Invention also consists in making and breaking the contact of the
sending portion or commutator of the block signalling telegraph instruments
worked on the one-wire system where only two signals are used, such as "blocked
and "clear," by a current being received through the receiving portion of such
apparatus, whereby when both sending and receiving needles of the instruments
are at or in their normal position of, say, "blocked" either of the signalmen of the
section can work the sending portion of the instruments, and move his index or
pointer to both sides, or raise and lower his miniature semaphore arm; but should
the receiving portion be placed to, say, 'clear" by a signalman from a distant
station the signalman at the receiving station is unable to transmit a
"clear" signal
to such distant station.
"
"
To enable us better to explain the utility and objects of this arrangement and
disposition of the connections of signalling instruments, we propose to describe its
application to a single line worked on the block system under the one-wire system
of signalling. For this purpose we will take three stations, which we designate A, B,
and C. The operator before a train leaves A going towards B obtains permission
from B by B placing A's indicating portion of the apparatus to "line clear," B
having given A the permission A is unable to give B permission to send a meeting
train; permission having been obtained A is enabled when a disconnecting apparatus
is used, such as is shown in Sheet 2, Figure 4, to lower his outdoor signal, and to
allow the train to enter the section between A and B. A then sends the bell code
to B to say the train has left A, (and) B in acknowledging his signal places the
indicating portion of the telegraph instruments to the "blocked" position, and in
so doing disconnects the outdoor signal, and enables it to rise to "danger," should
the sigmalman before sending the bell code to B have neglected to place his signal
to such position, and so have protected the train advancing to B; B then calls C,
and C places B's indicator to "clear," and unlocks B's outdoor signal. The signals at
A and C being locked or disconnected in the one direction of the line, and A, B, and
C signals being locked or disconnected in the other direction of the line, B's is the
only signal that can be lowered in the one direction as between B and C.
By the employment of the words "locked or disconnected," we mean to refer to
its being out of the power of the signalman to lower his own outdoor signal.
We have shown in illustration of our Invention block signalling telegraph instru-
ments worked on the one-wire system and disconnecting apparatus as fitted within
two signal cabins, and working in unison, and as applied to a section of single line
of railway over which trains are intended to run in either direction alternately,
showing our improved mode of connecting and disconnecting the continuity of the
battery circuit in the set of apparatus distinguished by the letter B.
In that portion of the Drawings, Figure 1, which represents station A we have
shown exterior views of the block instrument and the disconnecting apparatus, as
also the outdoor semaphore signal, whilst the internal arrangements and disposition
of the parts of a corresponding set of apparatus with their connections fitted at
station B are shown by an internal view (Figure 2) with the receiving index
lowered from station A to allow a train to proceed from B to A. The disconnecting
portion of the apparatus is bere shown as having been placed to the "clear
position.
"

page_text: "
It will be understood by reference to the apparatus, as shown in Sheet 2
(Figure 4), that should the miniature semaphore or receiving index be here placed
to its normal position of "blocked" or danger" by the signalman at A the out-
door signal at B would assume the "danger" position, by reason of the apparatus
being disconnected, as shown in Figure 4, Sheet 2, for when the miniature sema-
phore is placed to the position of "danger" the current traverses the coils and
attracts the armature to the coils, and to the end of such armature is attached a
stem (a) which strikes the lever (b), thereby releasing the tumblor piece (c).
The general arrangement of such disconnecting apparatus has been described
and illustrated in Specification No. 5/70.
In Figure 3, Sheet 1, we have shown an arrangement intended to be applied to
the locking plate described in Specification No. 336/7, whereby in absolute block
working the signalman is enabled to know whether a train is approaching him or
when one has left him, as the normal position of his miniature arms is "blocked"
or "danger" when a train is either on the section or clear of it.
It will be readily understood that although we have only shown in the accom-
panying Drawings the arrangement as applied to a one-wire system with an
insulated stop pin to make and break contact as between the miniature arm and
the insulated pin, so as to disconnect the outdoor signal simultaneously with the
sending portion of the instruments, whereby confliction in signalling is avoided.
Such arrangement may be readily applied to a two or more wire system in the
same manner by insulated pins or any other form of contact maker and breaker
where the miniature arms, indices, or pointers are actuated by reversed currents
either showing one, two, or three positions or signals, such as "line blocked," "train
on line," or "lino clear; or we may so arrange the commutator portion of the
sending instrument at A that when it is pinned over to the "train on line" position
it shall disconnect the receiving portion as between A and B, by reason of the
severing of the earth or line wires of the receiving indicating instrument.
"
We may also in some cases find it more convenient to use or employ two sets of
batteries, viz., one for the block instruments, and the other for the disconnecting
apparatus, instead of one battery applied to work both, as is shown in the Drawing
illustrating station B on Sheet 1.
We are aware that an apparatus has been heretofore described to work in con-
nection with block telegraph instrument, in which the outdoor signals at both the
ends of a section of single line of railway may be placed to the "clear" position
at one and the same time; but we wish it to be understood that our improvements
herein described prevent the outdoor signals at both ends of a single line section
from being lowered or placed to the "clear" position at one and the same time,
and thereby preventing two trains meeting from opposite directions on the same
section of a line.
But what we claim in connection with our improvements in the mode or method
of arranging and disposing the connections of electro-magnetic signalling instru-
ments as is herein described is,―
First. The arrangement and disposition of the connections of block signalling
instruments for the purposes herein described as illustrated upon the accompanying
Drawings, or any mere modification thereof.
Second. The arrangement of the parts of block signalling telegraph instruments
and the wire and other connections thereof, as herein described, for the purpose
of preventing confliction in signalling upon single lines of railways either in a one,
two, or three wire system of signalling, whether such arrangement be applied to
the commutator or sending portion or to the indicating and receiving portions of
such instruments.
Third. The arrangement and disposition of the connections and mode of joining
up the instruments, as shown in Figure 2, block station B, for the purpose of enabling
the action of the disconnecting apparatus upon the semaphore to be controlled by
the block instrument.
Fourth. The arrangement and disposition of the connections and mode of joining

page_text: up the instruments, as shown, for the purpose of enabling the block instruments to
be controlled by the position of the disconnecting apparatus in relation to the
battery or earth. connections.
In witness whereof, we, the said William Smith and Richard Robert Harper,
have hereunto set our hands and affixed our seals, this Seventeenth day of
March 1877
Witness,
H. H. M. SMITH,
19, Salisbury Sttreet,
W.C.
WILLIAM SMITH, C.E.
(L.S.)
RICHARD ROBERT HARPER. (L.S.)