Improvements in Electric Railways on a Road Contact System.
Year: 1897

page_text: Date of Application, 30th Nov., 1897-Accepted, 15th Jan.,
1898
COMPLETE SPECIFICATION.
Improvements in Electric Railways on a Road Contact System.
I, WILLIAM MILTON BROWN, of Johnstown, Cambria County, Pennsylvania,
United States of America, Electrical Engineer, 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:-
My invention relates to that class of systems in which non-continuous or isolated
contacts are interposed on the side of the circuit. The circuit between these con-
tacts and the source of supply is normally an open one, but is temporarily closed
by the operation of a circuit closer actuated by the passage of the vehicle.
My invention is especially adapted for that type of system, in which a magnet
carried by the travelling vehicle, serves to actuate the switching mechanism
within the contact box and relates to an improved winding of said magnet coils
and the connections from said winding to batteries and switches carried by the
car, whereby I am enabled to secure a strong magnet field regardless of the drop
in voltage which may be caused by the large amount of current sometimes needed
to start the vehicle from a state of rest; whereby I am enabled to excite the
magnet from the batteries at such times as there may be a temporary stoppage of
power; whereby I am enabled at any time to charge the batteries by merely
closing a switch while I am delivering current to the motors; and whereby I am
enabled to completely cut out the current delivered to the maguct coils whenever
the canopy switch is opened, thus causing no wasto or current when the vehiclo is
left by the operator.
The accompanying drawing represents a diagrammatic view of those parts of
the system which are required to illustrate my invention.
A represents the dynamo at the power station, one terminal of which is con-
nected to the rails B of the track, while the other terminal is connected by inter-
mediato feeders and sub-feeders, which are not here shewn, to the switching
mechanism within the contact box C. This switching mechanism as before
explained, is ordinarily opened, so that no current is delivered to the top of the
box, but it is closed by the field of the magnet carried beneath the travelling
vehicle.
At D, I shew a collecting shoe which makes contact with box C, only when the
aforesaid magnet is above the box. The current from the collecting shoo D passes
to the canopy switch E, so that when the canopy switch is opened, no current is
delivered to any of the circuits upon the vehicle.
From E, connection is next made in multiple to the controller F through a
series winding G for energizing the switch closing magnet. The other connection
from E to F is through the batteries H, which connection is normally kept open
by means of the switch I.
From the controller F, the current passes through the motors J-J and their
resistances, shunts, and so on, but which are not here shewn, to the ground side
of the circuit, which is represented by the car wheel K.
L represents a shunt winding for the coils of the magnetic closer.
M represents an auxiliary shoe which is electrically connected to the wheel K.

page_text: The passage of the current when the car is travelling under normal conditions,
would be as follows:-From the dynamo A to the contact box C, through the
switching mechanism which would be closed by the presence of the magnetic
closer, to the collecting shoe D), to the canopy switch E, thence part would be
shunted through the coils L to energize the magnet, and part would pass through
the low potential coils G still further energizing the magnet, the latter part then
going through the controller F and the motors JJ, returning to the power house
by means of the wheel K and the rail B.
If the car is at rest and there is a high enough resistance in the circuit between
the power house and the part of the line upon which the car is standing to cause
a heavy drop in voltage when the car is started, the shunt coils L may not energize
the magnet sufficiently, but the increased amount of current which passes through
the motors, and causes the said drop in voltage, also passes through the coils G
and increases their energizing power so that they will compensate for the loss of
power in the coils I,.
1
If the car is at rest and the canopy switch E is open so that no current is in
either the coils G or I, the switching mechanism within the boxes C, would, of
course, he open and no current could therefore, be received by the car. In this
event, the motorman closes the switch I, which is preferably a foot-switch placed
near the operator's position, and a circuit is made through the coils G with the 2
battery Has the source of power. This will energize the magnet sufficiently to
close the switching mechanism and as soon as this is done the switch I may again
be opened, the coils L being sufficient to keep the switching mechanism closed.
When the batteries need charging, it is only required that the motorman close
the switch while he is passing current through the controller and motors. In 2
this case, the current received by the motors will pass in multiple from E to F
through the coils G and the battery H, the latter part of the current serving to
charge the batteries.
If the contact portion of the box C, from any cause, remains alive after the
magnet has left the box, the shoo M, coming in contact therewith, will short cir-
cuit the box to the rail B, and open a safety device, such as a magnetic circuit
breaker, or a fuse, which may be at any desired part of the circuit.
I have shown my invention entirely in diagram and do not limit myself to any
mechanical construction of the parts thereof. Further I have shewn my invention
as applied to a vehicle apparently intended for normal travel in but one direction. 3
It is evident, however, that it will be mere duplication to so arrange the parts that
the car could be operated from either end, as it is usually done to-day.
It is also clear that I need not limit myself to the exact details shown and
described, for the scope of my invention is broader than the specific arrangement
by which the invention has been illustrated and can therefore, be readily modified
by any one skilled in the art.
Having now particularly described and ascertained the nature of my said
invention and in what mauner the same is to be performed, I declare that what
I claim is:
1. In an electro-magnet adapted to travel over fixed contacts and close the
circuit between said contacts and the source of supply, energizing coils comprising
a winding of comparatively high resistance connected to both sides of the circuit,
in combination with a winding of comparatively low resistance placed in a series
with motors for propelling a vehicle, said winding being adapted to simultaneously
co-operate in energizing the magnet.
2. The combination, in an electric system of propulsion, of a vehicle and a
magnet carried thereby having energizing coils consisting of one winding of com-
paratively high resistance and one of comparatively low resistance, said winding
being so connected to the circuits that current passes through both windings
simultaneously, when circuit is established through the motors.
3. In an electrically propelled vehicle, a magnet carried thereby having energiz-
5

page_text: ing coils comprising two distinct sets of winding, one winding being in shunt
with the motors carried by said vehicle, and the other winding being in series with
said motors.
4. The combination of an electrically propelled vehicle, motors carried thereby,
an electro-mugnetic closer also carried thereby, and an energizing coil for said
closer in series with the motors and connected through a switch to the terminals of
an independent source of electric supply carried by the vehicle.
6. The combination upon a vehicle, of motors for propelling the same, storage
batteries and a switch in circuit therewith, an electro-magnetic closer carried by
Baid vehicle, and energizing coils for said closer comprising two sets of windings,
one of said windings being in series with said motors, and connected when the said
switch is closed, to the terminals of the storago batteries, the other of said
windings, being in shunt with the motors.
6. The combination upon an electrically propelled vehicle, of contact makers D
and K, motors, a controller, storage batteries and a switch therefor, an electro-
magnetic closer and coils therefore having two distinct windings G and L, con-
nections of one of said contact makers through the motors to the controller, and
connections from the other of said contact makers either through said winding G
to the controller, or when said battery switch is closed, through coil G and the
batteries in multiple to the controller.
"
A
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.