improvements in means for signalling or Telegrapning between Railway Trains or between Trains and Stations by Induction.
Year: 1885

page_text: [Communicated from abroad by Thomas Alva Edison, of Menlo Park, in the
County of Middlesex and State of New Jersey, United States of America,
Inventor, and Ezra Torrance Gilliland, of Boston, in the County of Suffolk
and State of Massachusetts, United States of America, Electrician.]
improvements in means for signalling or Telegrapning between
Railway Trains or between Trains and Stations by Induction.
Ì THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent do hereby declare the nature of this invention for
"IMPROVEMENTS IN MEANS FOR SIGNALLING OR TELEGRAPHING BETWEEN RAILWAY
TRAINS OR BETWEEN TRAINS AND STATIONS BY INDUCTION," a communication to me
from abroad by Thomas Alva Edison of Menlo Park in the County of Middlesex
and State of New Jersey, United States of America Inventor, and Ezra Torrance
Gilliland of Boston in the County of Suffolk and State of Massachusetts United
States of America, Electrician, to be as follows:-
The object of the Invention is to produce practical and efficient apparatus for
signalling or telegraphing between moving railway trains or between trains and
stations by induction, and without the use of travelling electrical connections.
A further object is to utilize the ordinary telegraph wires for this purpose, and
to prevent the interference of the signals.
In carrying out the Invention, a signalling office is provided upon each train.
This may be a compartment in a baggage or other carriage which will be attached
to each train. At that point will be located the signal transmitting and receiving
instruments. This carriage will have placed upon its top or side, or upon each
side, a metallic condensing surface running the entire length of the carriage. This
metallic condensing surface will be a strip of metal, for illustration say a foot
wide, which will be supported well off of the carriage by blocks of glass; or it
may be thin sheet metal or metallic foil secured to canvas or other suitable
material and similarly supported from the carriage. To increase the total con-
densing surface, all the carriages of the train are preferably provided with such
condensing surfaces which are connected electrically together by suitable couplings
when the train is made up.
In the signalling office apon the train a conductor is connected with the
external condensing surface; and this conductor extends through the apparatus
about to be described to the carriage-truck, or to a metallic connection therewith
so as to form a ground or earth connection through the wheels of the carriage
and the rails upon which they travel. The apparatus referred to consists of an
induction coil, the secondary circuit of which is of extremely high resistance and is
connected in the line of such conductor. There is also located in the line of such
conductor a receiving telephone of high resistance and insulation which is preferably
an electro-motograph telephone, the chalk cylinder of which is kept in constant

page_text: rotation by a suitable motor electrical or mechanical; but a magneto-electric or
other form of telephone receiver may be used.
In the primary circuit of the induction coily are a local battery and a revolving
circuit breaker. This circuit breaker is a wheel having its surface broken by
cross strips of insulation; upon it rests a spring the circuit being through the
spring to the spindle of the wheel. This circuit breaking wheel kept in rapid
motion by a suitable motor, electrical or mechanical, the current vibrations
produced by it being a great number per second, and audible in the telephone
receiver.
This revolving circuit breaker is shunted by a back point key which normally
short circuits, the revolving circuit breaker and prevents it from affecting the
induction coil. A switch short circuits the secondary of the induction coil when
receiving and is opened in transmitting.
In lieu of this arrangement the primary of the induction coil may have only the
local battery and revolving circuit breaker while the secondary will be shunted by
a back point key which normally short circuits the induction impulses and also
cuts out the secondary in receiving.
The ordinary telegraph wires, run on poles at the side of the track and grounded
at their ends, are utilized collectively for conveying the signals. They form the
other surface of the condenser (the strips on the carriages forming one surface)
while the intervening body of air is the dielectric the two condensing surfaces
being connected by the earth.
In signalling between trains, signals will be transmitted by working the key
in the office upon one train. This will cause static impulses or variations in
static tension at the condensing surface upon the carriages, which will affect the
telegraph wires. These in turn will affect the condensing surface upon the
carriages of the other train and will cause impulses to ground which will be
audible at the telephone.
At each signalling station there will be erected between the telegraph wires a
large metallic condensing surface. This may be attached to a frame supported
from the telegraph poles or from separate poles erected between the telegraph
poles. A wire runs from this condensing surface to the station where it is
connected to ground through the same character of transmitting and receiving
apparatus already described for the carriages,
In lieu of using this condensing surface outside of station a separate wire may
be attached to each telegraph wire (or to each of as many as it is desired to
utilize) and run into the station where it will be connected to one side of a
condensor of ordinary form. The other sides of the several condensors will be
connected together and by a common wire to ground through the transmitting and
receiving apparatus.
The telegraph wires are kept constantly closed for transmitting the induction
impulses by shunting the regular Morse keys by condensors. The condensors
do not interfere with the carrying-on of the ordinary telegraphing over such wires,
at the same time that they form constantly closed paths for the induction
impulses independent of the working of the ordinary Morse keys.
The stations being connected for railway signalling inductively with the line
wires the same as are the trains, signals are received and transmitted by a station
the same as by a train. The trains and stations are connected inductively with
the line wires in multiple are so to speak signals being transmitted by keys,
circuit breakers and induction coils and received by telephones. The signalling
will be conducted by Morse characters or by numerical signals in accordance with
an established code.

page_text: Railway Trains or between Trains and Stations by Induction..
I THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex, Patent Agent, 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:-
:
The object of the invention is to produce practical and efficient apparatus for.
signalling or telegraphing between moving railway trains or between trains and:
stations by induction and without the use of travelling electrical connections.
A further object is to utilize the ordinary telegraph wires for this purpose and to
prevent the interference of the signals.
These objecta are accomplished in the manner hereinafter described with
reference to the several figures on the accompanying sheet of drawings to which,
I shall now proceed to refer, the same letters of reference indicating corresponding
parts in all the figures.
Figure 1 of the accompanying drawings represents a station and portions of two
trains with the apparatus for signalling.
Figure 2 a view of a carriage broken away to show the apparatus.
Figure 3 a cross section of carriages showing conductors.
Figure 4 an arrangement of apparatus at a station: and
Figure 5 a somewhat different station arrangement.
In carrying out the invention, a signalling office is provided upon each train..
This may be a compartment in a luggage van or other carriage A, which is attached.
to each train. At that point is located the signal transmitting, and receiving
instruments. This carriage has placed upon its top or side, or upon each side, a
metallic condensing surface running the entire length of the carriage. This
metallic condensing surface is a strip a of metal, for illustration say a foot wide,
which is supported well off of the carriage by blocks of glass b; or it may be thin
sheet metal or metallic foil secured to canvas or other suitable material and:
similarly supported from the carriage. To increase the total condensing surface
all the carriages of the train are preferably provided with such condensing surfaces >
which are connected electrically together by suitable couplings c when the train is
made up.
In the signalling office upon the train a conductor 1 is connected with the
external condensing surface; and this conductor extends through the apparatus
about to be described to the carriage-truck or to a metallic connection therewith,
so as to form a ground or earth connection through the wheels of the carriage and
the rails upon which they travel. The apparatus referred to consists of an:
induction coil B, the secondary circuit of which is of extremely high resistance and
is connected in the line of such conductor 1. There is also located in the line of
such conductor a receiving telephone C of high resistance and insulation, which is
preferably an electro-motograph telephone, the chalk cylinder of which is kept in
constant rotation by a suitable motor, electrical or mechanical; but a magneto-
electric or other form of telephone receiver may be used.
قي

page_text: In the primary circuit of the induction coil B, are a local battery d and a
revolving circuit breaker D. This circuit breaker is a wheel having its surface
broken by cross strips of insulation; upon it rests a spring the circuit being
through the spring to the spindle of the wheel. This circuit breaking wheel is kept
in rapid motion by a suitable motor, electrical or mechanical, the current vibrations
produced by it being a great number per second and audible in the telephone
receiver.
The revolving circuit breaker is shunted by a back point key E, which normally
short circuits the revolving circuit breaker and prevents it from affecting the
induction coil. A switch F short-circuits the secondary of the induction coil
when receiving, and is opened in transmitting.
Instead of this arrangement, which is shown in all the figures except figure 5, the
primary of the induction coil may have only the local battery and revolving circuit
breaker, while the secondary is shunted by a back point key G, which normally
short circuits the induction impulses and also cuts out the secondary in receiving.
This latter arrangement is shown in figure 5.
The ordinary telegraph wires 2, 3, 4, 5, run on poles H at the side of the track
and grounded at their ends, are utilized collectively for conveying the signals.
They form the other surface of the condenser (the strips on the carriages forming
one surface) while the intervening body of air is the dielectric, the two condensing
surfaces being connected by the earth.
In signalling between trains, signals are transmitted by working the key E in the
office. upon one train... This causes static impulses or variations in static tension at
the condensing surface upon the carriages which affect the telegraph wires. These
in turn affect the condensing surface upon the carriages of the other train, and
cause impulses to ground which are audible at the telephone.
At each signalling station I, there is erected between the telegraph wires, a large
metallic condensing surface K, (figure 4). This may be attached to a frame
supported from the telegraph poles or from separate poles erected between the
telegraph poles. A wire 6 runs from this condensing surface to the station, where
it is connected to ground through the same character of transinitting and receiving
apparatus already described for the carriages.
Instead of using this condensing surface outside of the station, a separate
wire (7, 8, 9, 10 Figures 1 and 5) may be attached to each telegraph wire (or to
each of as many as it is desired to utilize) and run into the station where it is
connected to one side of a condenser L, of ordinary form. The other sides of the
several condensers L are connected together and by a common wire 11 to ground
through the transmitting and receiving apparatus.
The telegraph wires art kept constantly closed for transmitting the induction
impulses by shunting the regular Morse keys M by condensers N. These con-
densers N do not interfere with the carrying on of the ordinary telegraphing over
such wires, at the same time that they form constantly closed paths for the
induction impulses independent of the working of the ordinary Morse keys. The
ordinary Morse relay and sounder are shown at O and P respectively.
The stations being connected for railway signalling inductively with the line
wires the same as are the trains, signals are received and transmitted by a station
the same as by a train. The trains and stations are connected inductively with
the line wires in multiple arc, so to speak, signals being transmitted by keys, circuit
breakers and induction coils, and received by telephones.
The signalling is conducted by Morse characters, or by numerical signals in
accordance with an established code.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed,. I declare that what
I claim is
1st In a system of railway signalling by induction, the combination with a
grounded line wire, of a moving carriage, having an external condensing surface,,

page_text: and signal transmitting and receiving instruments, located in a grounded connection
from such condensing surface through the rails upon which the carriage travels,
and a station having also signal transmitting and receiving instruments, located in
a grounded circuit, connected by a condensing surface with the said line wire,
substantially as hereinbefore described.
2nd In a system of railway signalling by induction, the combination of circuit
breakers, keys and induction coils, for transmitting signals, and telephones for
receiving signals, substantially as herein before described.
3rd In a system of railway signalling by induction, the use of the ordinary
telegraph wires for the transmission of the railway inductive signals without
interfering with the regular telegraph signals, substantially as hereinbefore
described.
4th The apparatus for railway signalling by induction, substantially as herein-
before described with reference to the accompanying drawings.