Improvements in Electric Signalling on Trains.
Year: 1892

page_text: Date of Application, 19th Jan., 1892
Complete Specification Left, 19th Oct., 1892-Accepted. 19th Nov., '892
PROVISIONAL SPECIFICATION.
Improvements in Electric Signalling on Trains.
I, ALEXANDER SHIELS, of 190 Bath Street, Glasgow, M.B., C.M., B.Sc., do
hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in electric signalling on trains.
The invention consists in fitting one or more semaphore or signal arms, worked
by electricity on each of the carriages. The semaphore and its accessories may
be of the same construction as that described in the Specification of my prior
Patent No. 13982, but in this invention no local battery or cell is used to actuate
directly the semaphore.
s:
On the engine is fitted or placed a battery of, say, 6 cells. The positive wire
from the battery is led to an electric bell, also on the engine, and from thence
through the carriage coupling, which may be of the construction known as the
Shiels and Elliot Coupling," to the first carriage, along which it is conducted, then
to the next carriage, and so on finally terminating in the guard's van, if the van
forms the end of the train. In the guard's van the wire is led to an electric bell
and then to the positive pole of a battery of, say, 6 cells.
The negative wire from the battery on the engine is led directly through the
coupling to the first carriage and then to the next and so on throughout the series,
finally terminating in the guard's van. In the guard's van the wire is led to the
negative pole of the battery.
The negative and positive wires thus form a circuit with the batteries and bells
as part of said circuit.
From the main or trunk positive wire there is led off in each carriage a branch
wire, which passes through the semaphore apparatus or apparatuses. The branch
wire has smaller branches, which are led into each compartment. The ends of
the small branch wires terminate in a circuit closer, fitted in each compartment.
The circuit closer may be in the form of a press button and somewhat similar to
that described in my prior Patent No. 10,260º¹.
A branch wire is also, preferably, led off the trunk positive wire in the guard's
van and likewise may pass through a semaphore apparatus and communicate with
a circuit closer.
Small branch wires are also led from the trunk negative wire, into each com-
partment and to the circuit closers.
With this method of signalling on trains, immediately a passenger pushes in the
press knob in a compartment, he closes the circuits of all the bells in the train, and
causes them to ring and also actuates the signal arm, on the carriage in which the
push is situated, so that the guard may know from what carriage the signal has
been given.
With the hereinbefore described arrangement, the current passes direct from the
positive pole of the batteries, to the bells and then round the circuit.
When the
batteries are fitted in the circuit in this manner, so long as the push knobs are not
pressed, no electric action on the bells takes place.
There may be two three or other number of guards' vans fitted in the train and
any desired number of electric bells, which can be arranged to ring simultaneously
when the push knobs are pressed.
If desired, instead of placing the bells in the positive circuit, they may be placed
in the negative circuit, that is to say, the negative wire passes first to the bells and
then to the battery.
Date : 10
CT
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in Electric Signalling on Trains.
I, ALEXANDER SHIELS, of 190 Bath Street Glasgow, M.B., C.M., B.Sc.,
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 relates to improvements in electric signalling on trains.
The invention consists in fitting one or more semaphore or signal arms, worked
by electricity, on each of the carriages. The semaphore and its accessories may
be of the same construction as that described in the Specification of my prior
Patent No. 13982 but in this invention no local battery or cell is used to directly
actuate the semaphore.
On the engine is fitted or placed a battery of, say, 12 cells. The positive wire
from the battery is led to an electric bell, also on the engine, and from thence
through the carriage coupling, which may be of the construction known as the
"Shiels and Elliot Coupling," to the first carriage, along which it is conducted.
then to the next carriage, and so on finally terminating in the guard's van, if the
van forms the end of the train. In the guard's van the wire is led to an electric
bell and then to the positive pole of a battery of, say, 12 cells.
The negative wire from the battery on the engine is led directly through the
coupling to the first carriage and then to the next and so on throughout the series,
finally terminating in the guard's van. In the guard's van the wire is led to the
negative pole of the battery.
The negative and positive wires thus form a circuit with the batteries and bells
as part of said circuit.
or
From the main or trunk positive wire there is led off in each carriage a branch
bye path wire, which passes through the semaphore apparatus or apparatuses.
The branch wire has smaller branches, which are led into each compartment. The
ends of the small branch wires terminate in a circuit closer, fitted in each com-
partment. The circuit closer may be in the form of a press button and somewhat
similar to that described in my prior Patent No. 10,260º¹.
A branch wire is also, preferably, led off the trunk positive wire in the guard's
van and likewise may pass through a semaphore apparatus and communicate with
a circuit closer.
Small branch wires are also led from the trunk negative wire, into each com-
partment and to the circuit closers.
With this method of signalling on trains, immediately a passenger pushes in the
press knob in a compartment, he closes the circuits of all the bells in the train,
and causes them to ring and also actuates the signal arm on the carriage in which
the push is situated, so that the guard may know from what carriage the signal
has been given.
With the herein before described arrangement, the current passes direct from
the positive pole of the batteries, to the bells and then round the circuit. When
the batteries are fitted in the circuit in this manner, so long as the push knobs are
not pressed, no electric action on the bells takes place.
There may be two, three or other number of guard's vans fitted in the train
and any desired number of electric bells, which can be arranged to ring simul-
taneously when the push knob is pressed.
If desired, instead of placing the bells in the positive circuit, they may be placed
in the negative circuit, that is to say, the negative wire passes first to the bells
and then through the circuit.
And in order that my said invention may be properly understood I have hereunto
appended, by way of example, two explanatory sheets of drawings, whereon:
Fig. 1 is an outline plan view, of a train composed of an engine, two carriages

page_text: and two guard's vans fitted with electric bell communication.
divided into two parts so as to get it into the required space.
Fig. 2 shows the end of a carriage.
The view has been
Fig. 3 is an outline plan view of a carriage showing the electric wires as arranged
differently from Fig. 1.
Fig. 4 is a side view of a "Shiels and Elliot" electric coupling for trains.
Fig. 5 is a diagram.
Referring to the drawings whereon the same reference letters wherever repeated
indicate similar or like parts :-
The train, as shown at Fig. 1, consists of an engine a, guard's vans b, b', and
carriages c, c. d represents an electric battery placed on the engine, d¹ represents
an electric battery placed in the first guard's van b, and d represents an electric
battery placed in the last guard's van '. e represents an electric bell fitted on the
engine, e represents an electric bell fitted on the guard's van b and c represents
and electric bell fitted in the last guard's van, represent signal boxes
fitted on the ends of the carriages c, c', f' (Fig. 2) are semaphore or signal arms.
for calling the attention of the guard or engine driver.
g³ are "Shiels &
Elliot electric couplings between the carriages. represent "push knob
circuit closers placed in the compartments of each carriage and also in the guard's
The thin line represents the positive wire or lead of the electric system
whilst the dotted line represents the negative wire or lead of the system.
van.
In Fig. 1 the trunk positive wire i is led from the positive pole of the battery d,
on the engine, first, to the electric bell e, then through the coupling g to the guard's
van ; then along the guard's van and through the coupling y¹ to the carriage c.
From the carriage e the trunk wire i passes through the coupling g² to the next
carriage c and from that carriage through the coupling g³ to the guard's van b¹at
the end of the train, where it passes to the bell and battery d.
The trunk negative wirej passes from the negative pole of the battery d round
the end of the guard's van and through the coupling g³ to the carriage e. From
the carriage e' it passes through the coupling and along the carriage c, through the
coupling, to the guard's van b. From the guard's van it passes, by the coupling g,
to the engine and terminates at the negative pole of the battery d, thus completing
the circuit.
As will be noticed, with this arrangement of wires, the batteries d, d² and bells e, e²,
are in the electric circuit.
Branch positive and negative wires i, j, are led to the front of the engine and
coupling, so that, should the engine be coupled by the front instead of by the
back, the electric circuit throughout the train will still be complete.
A positive branch wire, is conducted first to the bell e and then to the
battery, in the guard's van b, and, in order to complete this subsidiary circuit of
which the main system forms a part, a negative branch wire is also led to
the battery d³, The circuit closer is connected to this subsidiary circuit by
the wires,
A branch or bye path "wire is led, from the positive trunk wire at k (at the
front end of the carriage c) first through the magnet or other electrical device for
actuating the signal arm in the box fand then to the magnet or electrical device
for actuating the signal arm in the opposite box f. From the box the "bye path'
wire passes along the carriage to the other end, where it is conducted to a circuit
closer in the end compartment m of the carriage. A negative wire connects this
circuit closer with the trunk negative wire j. Short branch positive and negative
wires i³, 1º, 7 and joj jare led to the circuit closers h in the other compartments n
of the carriage c.
It will be seen that the "bye path" wire with its branches
forms a subsidiary circuit with the main system as a part of said circuit.
The carriage has, likewise, a "bye path" positive wire with its branches for
connecting the several circuit closers and the electrically actuated signals, j',
with the main system.
The guard's van 61, has, similarly to the engine a, branch wires, leading to

page_text: the end coupling g', so that, should the van be turned round and attached to the
train by the coupling at g, instead of that at g³, it would not affect the electric
system throughout the train.
It might, at first sight, be supposed, that, as the external circuit with its batteries
and bells is always complete, independently of the opening or closing of the pushes /
in the different compartments, the bells e will ring continually. This supposition
is, however, erroneous, as I have found, that, by first leading the positive wire from
the battery, d, to the bell e and then through the external circuit, the bells will not
ring until one of the circuit closers is closed. It might also similarly be supposed,
as the wires i, j, on the engine and van 6 form with the wires 12, 1, an inner circuit
which is always closed, that the bells and e¹ would ring continually. This is not
so, however. The reason of this apparently strange action, in my opinion, is,―
supposing we take the smaller circuit as shown in diagram at Fig. 5--that there are
two batteries d, d¹ in the circuit of equal or nearly equal voltage and that the
current tending to pass from the positive pole P of the battery d, along the wire i
in the direction of the arrow is counter balanced by a current of equal or nearly
equal voltage tending to pass in the reverse direction (see arrow s) along, the same
wire, from the positive pole P1 of the battery d. As these currents counterbalance
one another the electric fluid on the wire is held in a state of electric equi-
librium i.e. there is no recognisable "flow" of current in either direction.
negative wirej passes from the negative pole N of the battery d direct to the
negative pole N of the battery d' there is, likewise, a tendency of negative currents
flow in opposite directions as shown by the arrows u, t, and, so, also produce a
state of electric equilibrium in the negative wire j.
to
::
2
As the
Immediately the push is pressed so as to close the circuit on the branch
wires the electric " fluid is set in motion and the bells and e' ring simul-
taneously. The reason of this is, that, when the push is pressed practically two
circuits are formed in the system, the first circuit passing from the positive pole P
of battery d through belle and along the wires and 3 through the circuit closer h
and back along the negative wires and to the negative pole of the battery d;
the second circuit passing from the positive pole P₁ of battery d' through the bell e'
and along the wires i and, through the circuit closer h, and back through negative
wires j3 and j to the pole N of the battery d.
A precisely similar action takes place with the larger external circuit running
throughout the train, saving, that, in this case, when a push, in any compartment or
guard's van is pressed so as to set the electric fluid in motion, three, practically
independent, circuits are formed, i.c. one circuit for each battery in the train.
Any number of batteries and bells may be fitted in the train with precisely
similar results, it being always borne in mind, however, that each of the batteries
must be of the same or nearly the same voltage.
In Fig. 3 the "bye path " wire j' is a negative wire instead of a positive one as
at Fig. 1.
If so desired the negative wire j can be first led from the battery d to the bell e
and then through the external circuit and the positive wire be led in a similar
manner to the negative wire in Fig. 1. This system of fitting the wires gives the
same results as that at Fig. 1 but the action is slightly weaker.
The wires, bells, and batteries may be arranged in any suitable way, care being
taken, however, that each battery and bell is geared up, i.e. connected with its wires,
in a precisely similar manner.
::
As will be noticed in Fig. 1 the "bye path" or branch wire in the carriage c
and the one in the carriage c¹ is a branch from the positive lead i, passing through
the signal boxes, and has the positive branches leading to the "pushes" or
circuit closers in the compartments. The reason for having a "bye path
wire
is to obviate the necessity for using an electric battery in each signal box and to
save extra wire connections to the circuit closers in the compartments. With this
arrangement, when one of the pushes his pressed, the electric current passes from
the trunk wire through the signal boxes and operates them, then passing through

page_text: the circuit closer and back by the negative branch wire to the trunk negative
lead j.
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If a "bye path wire was not used all the signals throughout the train would be
operated, instead of only the signals on the carriage in which the push has been
pressed.
The "bye path" wire, in Fig. 3, is a branch from the negative lead or trunk
wire.
The train may be composed of a number of carriages and vans.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :--
1. The hereinbefore described system of electric signalling on trains, substantially
as set forth.
" wires
2. In electric signalling on trains the application and use of "bye path
for actuating the signals on the carriages, substantially as hereinbefore set forth.
Dated this 18th day of October 1892.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent