Improved Means for Supplying Current to Electrically Propelled Railway Vehicles.
Year: 1898

page_text: Date of Application, 27th Sept., 1898-Accepted, 3rd Dec., 1898
COMPLETE SPECIFICATION.
Improved Means for Supplying Current to Electrically Propelled
Railway Vehicles.
I, GEORGE WILLIAM JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Chartered Patent Agent, do hereby declare the naturo of this invention (which has
been communicated to me from abroad by Stilson Hutchins, Publisher, a Citizen of
the United States and a resident of the City of Washington in the District of
Columbia) 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 electric railway equipments particularly to that systein
in which the working current is taken from contact buttons, plates or short sections
which by electro-magnetic action are successively brought into electric connection
with the feed wire, as the car bearing the motor travels over the line. The
invention consists in novel methods of arranging the circuits, contacts and other
electric parts of the system whereby the system is improved, simplified and made
more certain and accurate in its working.
In the accompanying drawing, which represents diagrammatically the features of
an electric railway system essential to an understanding of this invention, it is
shown applied to a system equipped to use alternating electric currents of high
tension, which are by suitable devices transformed to currents of less tension which
the motors are arranged to receive and utilize.
In the drawings 2, 3, represent the main conductors or leads from the
generator G, which in this instance is supposed to be an alternating current dynamo
adapted to generate a current of high voltage. T, T, represent transformers
situated at suitable distances apart along the line, the primary coils, 4, of which
are arranged in parallel between the mains 2 and 3, and the secondary coils 5 of
which, are arranged in parallel between the supply or feed conductor, 6, from which
the current is taken directly to the sectional conductors or contacts, and the returu
conductor R, which in this instance is represented as being one of the rails on which
the cars travel. These transformers reduce the current, in a manner well known, to
a voltage suitable for the motors, Mo., arranged upon the cars. S represents a
contact shoe carried by the car and connected with the motor circuit by a
conductor 8. The shoe is arranged to contact with buttons or plates, 9, arranged
at suitable distances apart and connected, through switching mechanisms, with the
feed wire, 6. These switch mechanisms are arranged in boxes, situated below the
surface of the ground and are properly insulated; but as the protection and
mounting of these parts of an electric railway equipment are well understood and
form no part of this invention they are not illustrated.
The switching devices are duplicates one of the other, and the circuits and electric
connections of one of them will first be described. 10 is a conductor leading from
the feed wire 6 to an armature lever 11, which is shown as pivotally connected with
the movable core 12, of a hollow electro-magnet M. This armature lever is adapted
to make four contacts 13, 14, 15 and 16, when raised, or attracted by its magnet.
The contact 13 is connected by a wire 17 with one of the buttons or plates, 9, and
in its course is coiled a few times around the magnet M, thus constituting a low

page_text: resistance coil 18. This conductor 17 serves to take the current which operates the
motors, from the feed wire 6, to the contact buttons 9, and is preferably formed of
a wire of low resistance, and constitute the working current circuit of the sectional
contact station. From the contact 14 a wire 19 connects with the working current
circuit, 17, beyond the electro-maguet,-that is, on the side nearest the contact
button, 9, and constitutes a shunt circuit in which is included a coil 20 around the
magnet M, of higher resistance than the coil 18. This circuit is not essential to
this invention, and might be omitted, but I prefer to retain it, because when the
lever 11 is raised to make contacts 13 and 14, that portion of the current which
takes the shunt circuit 19 in passing through the coil 20 increases the potential of
the electro-magnet above that which it has from the current passing through the
coil 18 of the working current circuit, and this serves to insure the armature lever
making good contacts and being held securely in place. The contact 15 is con-
nected by a wire 21 with the coil 20 of the magnet, M¹, of the station in advance
of the one now being described; and the contact 16 is connected by a wire, 22,
with the coil 20 of the magnet M2 at the station in the rear. It will be seen that by
means of the construction just described the contact buttons, 9, both in front and
rear of the one or ones engaged by the shoe 8 are connected, through shunt circuits
and the coils 20, with the feed wire, 6; and that as soon as either of these circuits
is coupled by the engagement of the shoe with the button or plate 9 connected
therewith, the magnet in such circuit will be energized and the armature thereof
attracted, making the contacts 13, 14, 15, 16 and switching on the working current
through circuit 17, at the station just operated.
By connecting the buttons or contact plates, on either side of the station through
which the current is being taken to the motor, with the feed wire, the car may be
made to run in either direction upon the track, and such connections would be
employed on a single track road; but where the road is double tracked, and the cars
on one track are supposed to run always in one direction, the rearward connections,
-16 and 22-night be omitted. But these connections may be retained under all
circumstances, so as to make it possible to run the cars in either direction as
required.
At 25 there is indicated a circuit upon the car connected at one extremity with
the conductor 8 which supplies current from the shoe S, and at its other extremity
with the return rail R, through the frame work of the car or in other suitable
manner. Suitable resistance may be introduced into the circuit, as represented
at 24. By means of a switch 23 either the motor or this circuit 25 may be ent
into or out of the circuit supplied through the wire or conductor 8; but this switch
should be so arranged as that there is never a complete break of the circuit when a
change in circuit is being made by the operation of the switch. The function of
this circuit 25 is to insure a sufficient flow of current through the station, with
which the shoe may be in connection, whenever the current is turned off from the
motor, and whether the car be in motion or standing still,-in order to keep the
armature levers raised or attracted, so that current may be instantly supplied to
the motor whenever required.
The drawing shows, diagrammatically, a motor car and five contact stations,-by
which term is included the contact button or plate with which the shoe engages,
and the switching devices in connection therowith. The magnets of the severa!
contact stations are desiguated M³, M², M, M¹, M"-beginning at the right of the
drawing, and the shoe of the car is represented as being in contact with the
buttons which are connected directly with the magnets M2 and M. Under these
conditions the working current from the feed wire, 6, is taken at these two stations
and current is taken whether the car be in motion or standing still; in the former
case the complete circuit being through the motor, and in the latter through the
circuit 25. The armature levers 11 at these two stations are both elevated by
reason of the attraction of their magnets M2 and M, and by their position they
close the contacts 13, 14, 15 and 16. The contact 13 of the magnet M² station
completes a circuit through which the working current is supplied as follows:-
;

page_text: from feed wire 6, by wire 10 to the armature lever, contact 13, working circuit 17,
-including the coil 18,-to the button or contact plate 9, where the car shoe takes
the current and passes it to the motor and the return rail in the usual or an approved
manner. The current through the magnet coil 18 energizes the magnet and
holds the armature lever in place. The contact 14 completes the shunt circuit 19
which includes the high resistance coil 20, the current diverted through this
serving to augment the force of the electro-magnet to secure the armature lever being
held in place. Like conditions to those just described exist at the station of the
magnet M. The contact 15 of the magnet M² station connects through the shunt
circuit 21 with the coil 20 of the magnet M of the station in advance; and the shoe
being in contact with the button 9 of that station a complete shunt circuit is formed
and continues so long as the shoe contacts with the two buttons as shown in the
diagram. The contact 16 of the station M² puts the coil 20 of the magnet M³ of
the station in the rear, in circuit with the feed wire 6, through the wire or shunt
circuit 22; but as this circuit is broken at the button 9 of this rear station no
current passes, the magnet M³ is not energized, and the armature lever thereof is
retracted, breaking the several contacts of that station. It will be understood,
however, that should the car move backward, or in the direction opposite to that
indicated by the arrow in the diagram, as soon as the shoe comes into contact with
the button of the station of magnet M³, a circuit will be completed through the
coil 20 of such magnot as follows: contact 16 of magnet M², shunt circuit 22,
coil 20 of magnet M³, circuits 19, and 17, button 9, shoe and car connections,--
which will cause the magnet to be energized, the armature lever to be attracted
and the several contacts at the magnet M³ station to be made, when the conditions
will be the same as have been described with reference to magnet M² station.
:
If the car moves in the direction of the arrow from the position indicated in the
diagram to one in which the shoe is in contact only with the button of magnet M
the following result will take place as the shoe leaves the button of magnet M² all
current through such magnet will be cut off and the armature lever will fali,
breaking all the contacts at this station. The breaking of the contact 16 at this
point will cut out of circuit the coil 20 of the magnet M³ in rear; but the coil 20
of the magnet M2 will still be in circuit with the feed wire by reason of the
connection at contact 16 of the magnet M. The coil 20 of the magnet M', in
advance of the station M, is in circuit with the feed wire by reason of the contact
15 and connecting wire 21, as it was when the parts were in position of the
diagram. If now the car further advances until the shoe contact with the button
of the magnet M the circuit will first be completed through contact 16, wire 21,
and coil 20, energizing magnet M and causing the armature lever to be lifted,
when the positions of the parts at the stations of magnets M and M¹ will be the
same as those shown in the diagram with reference to stations M² and M.
It will thus be seen that the current is taken directly from the feed wire only
through working curront circuits of the switching stations with the buttons of
which the car shoe may be in contact; and that the magnets on either side of the
stations in actual use are in circuit connection with the feed wire, through con-
nections controlled at the station or stations actually in use, but these circuits are
not complete until contact of the shoe with the buttons is actually made.
It is of course to be understood that if the rearward shunt circuit were omitted,
as in a double tracked road then the magnets of the forwards stations only would be
connected with the feed wire through contacts made at the station in actual
working relations.
While the invention has been illustrated and described as applied to an
alternating current system, it should be remembered that it is in its essential
features equally applicable to a system employing direct currents.
In place of buttons or contact plates, and a shoe,-sectional rails, and a contact
brush carried by the car might be employed. Whichever arrangement be used,
for reason of safety, the surface contacts should be so arranged that the bar body

page_text: covers all such contacts as may at any time be made alive by the operation of
the car.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :--
1. An electric railway system comprising a feed main, separate contact stations,
circuit connections for the working current between each contact station and the
feed main, each including a single electro-magnet, switching devices controlled by
such magnets whereby the working circuit is made and broken, and circuit
connections at each station, controlled by such switching devices, and each
connected with the magnet in the working circuit of another station, substantially
as and for the purposes herein before described.
2. An electric railway system comprising a feed main, separate contact stations,
au electro-magnet and switching devices controlled thereby for each station,
circuit connections for the working current including the said electro-magnets, and
extending directly between the feed main and the contacts, such circuits being
made and broken by the said switching devices, and shunt circuits controlled
by the said switching devices, and each including the electro-magnet of a station
other than the one through which the working current is passing, substantially
as and for the purposes herein before described.
3. An electric railway system comprising a feed main, separate contact
stations, an electro-magnet having a high and a low resistance coil, for each
station, switching devices. operated by the magnets for controlling the circuits,
circuits for the working current including the low resistance coils of the magnets,
and circuits including the high resistance coils of the magnets, such circuits
being controlled by the switching devices at stations beyond the magnets with
which they are connected, substantially as and for the purposes herein before
described.
4. An electric railway system comprising a feed main, separate contact stations,
an electro-magnet at each station, switching devices, operated by each magnet
for controlling the circuits for the working current at each station, and shunt
circuits at each station extending in either direction therefrom and including
coils of the electro-magnets at the stations both in advance and rear of the
station where they are controlled, substantially as and for the purposes
herein before described.
5. An electric railway, comprising a feed main, separate contact stations,
an electro-magnet at each station, switching devices actuated by the electro-
magnets, contacts arranged to be made when the switching devices are actuated
and thereby brought into circuit with the feed main, working current circuits
each from one of the said contacts through a coil of the electro-magnet which
controls the making and breaking of its circuit, to the contact for the collector
carried by the cars, shunt circuits each extending from one of the said contacts
through a coil of the electro-magnet at the station in advance, and other shunt
circuits, each extending from one of said contacts through the coil of the electro-
magnet at the station in rear, all the said shunt circuits connecting with the
contacts for the car collector, substantially as and for the purposes hereinbefore
described.
6. An electric railway comprising a feed main, separate surface contact stations,
and the following described apparatus at each station: vis. :-
:-an electro-magnet
having two coils 18 and 20, an armature actuated switch connected with the feed
main, the contacts 13, 14, 15 and 16, which are made when the armature is
attracted, a circuit for the working current extending from the contact 13 to the
surface contact and including the coil 18 of the electro-magnet, a shunt circuit
from the contact 14 to the surface contact including the coil 20 of the electro-
magnet, a shunt circuit from the contact 15 to the surface contact of the station
advance and including the coil 20 of the electro-magnet of such advance station,

page_text: and a shunt circuit from the contact 16 to the surface contact of the station in
the rear, and including the coil 20 of the electro-magnet of such rear station,
substantially as and for the purposes hereinbefore set forth.
Dated this 27th day of September 1898.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.