Improvements in Systems of Controlling Electrically Propelled Railway Trains.
Year: 1899

page_text: Date of Application, 13th May, 1899-Accepted, 8th July, 1899
COMPLETE SPECIFICATION.
Improvements in Systems of Controlling Electrically Propelled
Railway Trains.
We, THE BRITISH THOMSON-HOUSTON COMPANY, LIMITED, of 83, Cannon Street,
in the City of London, Electrical Engineers, do hereby declare the nature of this
invention (which has been communicated to us from abroad by Harold W. Buck,
residing at Schenectady, in the County of Schenectady, State of New York, United
States of America, Electrical Engineer), and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement;
-
The present invention relates to the electric control of railway motors and
trains. Many such systems have recently been devised, embracing the principle
of utilizing interchangeable motor-cars, all of which are equipped with the usual
collecting devices, motors and controllers, of identical design, or of such design
that the cars may be operated conveniently in the same train; to these equip-
ments so-called "master controllers" being added, by means of which all of the
motors of the train are simultaneously regulated to obtain the desired torque
and speed and to be stopped and started together. The general principle here
stated has been carried out in a number of different ways, some of which provide
ordinary continuous current motors, now commonly called "pilot motors," for
rotating the controlling devices, each car having a controlling device for its own
motors, and the arrangement of the circuits from the master controller being
such that the different motors which are geared to the controller are rotated to
the same extent and practically simultaneously. Another system dispenses with
the rotating motor and substitutes separately controlled contacts, which may be
operated by any convenient source of power, such as compressed air or electric
current applied by magnets or similar devices.
It is to the first named class of systems that this present invention relates;
but by it, instead of using the ordinary continuous current motor for rotating
the different controllers, there is employed a novel device which is rotated by
means of two-phase currents, themselves derived from the ordinary continuous
current supply by an intermediate mechanism which is operated as the master
controller. The motor-controller operating part of the system consists of a
gramme ring with leads passing to it at a number of points, in this application,
four. Within the ring is a bar magnet which is usually provided with a certain
amount of field magnet winding connected across the mains, and which operates
as a revolving field. The master controller transmits two-phase currents to the
gramme ring, polarizing the latter in the customary way, so that a so-called
rotary field is set up, with the line of polarization of which the bar magnet keeps
step in its action. The frequency of the derived two-phase currents depends upon
the speed of rotation of the master controller. The latter device consists briefly
of a pair of rheostats so connected across the mains that as one of them is cut
in the other is cut out, and the circuits of the gramine ring are connected at

page_text: four points to the rheostat switch, so that by the rotation of the latter two-phase
currents, as already pointed out, are set up.
The invention will be better understood from the accompanying drawings, in
which Fig. 1 is a side elevation in diagram of a train equipped with the invention;
Fig. 2 is a diagram of the circuits, and Fig. 3 is a large view of the synchronous
operating device or master controller connected to the motor controller apparatus.
For convenience of description, Fig. 3 may be first referred to. In this A is
the master controller, which consists of the two resistances A', A2 with a common
connection to the ground wire GW of the controller. At the ends of the
resistances are dead contacts A4, A4, and a contact A3 which is connected to the
wire 1, which, as will be seen in Fig. 2, is the trolley lead passing through the train.
It will be observed that the resistance sections progressively increase from
the common connection between the two to the contacts adjacent to the dead
contacts A. Collector rings a¹ to at are connected to brushes B to B respectively,
the brushes rotating in quadrature over the rheostat contacts, and brushes b¹, to b
rest upon the respective collector rings. Each of these latter brushes is connected
by a lead to one of the brushes h¹ to on the motor controller operating device C.
This consists of the gramme ring of the usual form, into which the leads from
the rheostat are connected at points in quadrature. The field magnet C¹ is
provided with a collecting device c and a coil which is connected across the
mains.
The operation of these parts is as follows; in the illustrated position current
flows from the two brushes B', B upon the contact A³ of the rheostat through the
collector rings to the collector ring brushes 61, 4, and thence to the points h¹, h*.
of the gramane ring. These two points being at equal potential, no current flows
in the section of the ring included between them; but current passes to the leads
leaving the ring at h2, h, between which points no potential difference exists,
to the brushes 62, 63, and thence out at the brushes B3, B³ of the rheostat and
through portions of the resistances to the ground wire. This connection establishes
a line of polarization coincident with the illustrated position of the field magnet.
Suppose now that the rheostat arms be turned to the right, resistance A¹ is cut
out gradually and resistance A2 is increased. Assume for instance that the
brush B is on the last contact of the resistance A', brush 133 being on the last
contact to the right of the resistance A2, and brushes B and B on the contact A³.
Under these conditions the line of polarization will be shifted so as to nearly
coincide with the points, 3 of the gramme ring, and the magnet C¹ will take a
corresponding position; and when the brush 12 is connected directly to the
wire GW the brushes B1, B3 will be on the dead contacts A+, so that no current
flows across them, or from lead to ³ of the gramme ring, the entire current
passing from to h² and establishing a line of polarization passing directly
through the leads ³, h³; the field magnet will then take a corresponding position.
It is manifest that if this operation is continued, the magnet C¹ will rotate as
waves of two-phase current pass around the gramme ring, the line of polarization
rotating as the rheostat brushes rotate. Thus any determined position may be
given to the field magnet,
Referring now to the other figures, Fig. 1 shows cars L1, L2, L3, each of which
is equipped with the apparatus shown in Fig. 2, the apparatus being indicated
in Fig.
only diagrammatically. In Fig. 2 however, in addition to the trans-
mitting device, as illustrated in Fig. 3, the other parts necessary to make up a
commercially operative train-control system are indicated. At A is one of the
master controllers or transmitters. This is geared to the handle D by the
gears E, E, so that it has a somewhat increased rate of rotation relative to the.
handle. The motive part C of the transmitting arrangement is also connected. by
gears F, F to the controller K, which is adapted to operate the motors in any
usual or convenient way. The motors are not illustrated, nor are the circuits of
the controller K shown, as they would unnecessarily complicate the diagram, it
being understood that any one of the well-known systems of control, preferably a

page_text: series parallel system, would be employed. For the motive part of the trans-
mission apparatus a two-phase synchronous motor may be substituted if desired,
as shown at M on the right of the diagram; but ordinarily this would be, more
expensive and less desirable than the arrangement shown.
The operation of this arrangement as illustrated is as follows;-When the
handle is turned, the transmitter A is rotated and sends two-phase current
through the motive device C, rotating the controller K to shift the motor circuits
in the usual manner. Of course any number of motor devices may be connected
in multiple, as is indicated from the coupling devices diagrammatically shown
between the two sets of apparatus shown in the figure, and all would be simul-
taneously operated.
With the arrangement thus shown some other contrivance is needed to operate
the reversing switches; this is shown in the form of a simple throw over
device P', which would be connected in any usual or desired manner to the
reversing switch of the controller. In order to make the diagram more clear no
attempt has been made to show this connection, which can be readily effected
in many well known ways. The throw-over device P is provided with stops P
and a coil Q upon its armature. A field magnet coil O is in circuit between the
trolley and ground, and remains constantly energized. A manually operated
switch RS is provided on each car adjacent to the master controller; this is like
the ordinary reversing switch, provided with contacts 1, 2, 3. It will be seen
that when the switch for instance touches the contacts 2, 3 a circuit is com-
pleted from the trolley wire 1 (which is connected to the trolleys T, here shown
as the shoes of a third rail system, in the usual way), to the lead, to the left
hand switch blade, through the coil Q, back to the right hand switch blade,
through the coil Q, back to the right-hand switch blade, contact and to ground;
thus throwing the armature P against one of the stops p. When the switch-
blades, however, touch the contacts 1, 2, this circuit is reversed and the armature
is thrown against the other stop, of course with a corresponding shift of the
reversing switch to which it is connected.
As thus described the device has all of its parts in circuit. It is at times
desirable to cut out the master controller, and for this purpose the switches S, S
are provided, as shown. Ordinarily these switches would be mechanically geared
to the master controller, so that with the first movement of the latter the
switches would be closed, but this it is unnecessary to illustrate or describe.
Of course trailer or idle cars without motors or controllers could be used in
the train without effecting the invention, it being only necessary to carry the
circuit-wires through them in a cable.
Where the current to be handled by the converting device A is of higher
potential than usual, a second rheostat like A', A2 may be substituted if desired
for the contact A3; but ordinarily this will not be needed.
Having now particularly described and ascertained the nature of our said
invention (as communicated to us from abroad) and in what manner the same
is to be performed, we declare that what we claim is; -
1-In a train control system, a master controller, propelling motors and a motor
controller for each motor car, an alternating current motor operating each motor
controller and circuits controlled by any master controller for supplying alternat-
ing currents to all of the alternating current motors.
2-In a train control system comprising motor cars each equipped with its own
master controller, motors, motor controller and collecting device, a polyphase
motor connected to and operating each motor controller, and means for supply-
ng all of the polyphase motors with current at desired times.
3-In a train control system, one or more motor cars each equipped with motors,
motor-controller, and collecting device, each motor controller connected to and
operated by a polyphase motor, and master controllers upon each car by the

page_text: actuation of any one of which polyphase.currents are supplied to all the motors,
thereby actuating them to the desired extent.
4. In a train control system, motor-cars each having a collecting device,
motors and a motor controller, polyphase motors operating the different controllers,
a continuous current supply system, and hand-operated devices between the
supply and the polyphase motors by the rotation of any one of which polyphase
current are derived from the continuous supply and transmitted to the polyphase
motors.
5. In a train control system, a rheostat connected across the continuous current
supply mains, angularly displaced brushes rotatable over the rheostat contacts and
cach connected to a point in the windings of one or more polyphase motive devices
and motor controllers operated by each of the latter devices.
6-In a train control system, a rheostat connected at its middle point to one of
the supply mains, a contact connected to the other main, angularly displaced
brushes moving over the rheostat contacts each connected to the windings of
one or more polyphase motive devices, and motor controllers operated simul-
taneously by the polyphase motive devices.
.
7-In a system of electric motor control, the combination of a source of supply,
one or more motors, a controller therefor, and an electro-motive device responsive
to alternating or shifting currents for actuating said controller.
Dated this 9th day of May 1899.
THE BRITISH THOMSON-HOUSTON COMPANY LIMITED,
A. R. MONKS,
W. MARTINDALE,
}
Directors.
ALFRED CLEMENTS, Assistant Secretary.