Improvements in Circuits for Electric Railways.
Year: 1890

page_text: Date of Application, 9th Dec., 1890-Accepted, 17th Jan., 1891
COMPLETE SPECIFICATION.
Improvements in Circuits for Electric Railways.
1, FRANK WEIDENER SABOLD, of 348 Clinton Avenue, Albany, New York, Telegraph
Manager, 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 :—
Figure 1 is a plan view of a railway embodying my invention;
Figure 2 is an end view of the sime; and
Figure 3 is an enlarged transverse section of the railway tracks, showing the mode
of forming electrical connection between said tracks and the earth.
It is a well known fact that the earth-a very few feet beneath its surface-offers
no perceptible resistance to the flow of the electric currents, and, for that reason. it
forms the best and cheapest known conductor that can be used for the purpose of
conducting electric currents.
My invention consists in combining with an over-head electric conductor, the track-
rails of a railway which are electrically connected with a series of metallic bars
inserted in the ground adjacently to, and in line with, the railway-tracks; said bars
being spaced apart at a distance which will correspond to the length of an ordinary
track-rail, or nearly so, so that a car, equipped with the usual motor and conductin
wires, will-in its transit over said tracks-effect a constant variation in the length
of the electric circuit, making the latter longer or shorter according to the direction
in which the car is moving in respect to the generator; the course pursued by the
electric current, from the dynamo or generator, being through the over-head
conductor or trolley-wire, downward through the conducting wires of the car to the
track-rails, thence to the metallic baus through the wires connecting said bars with
the track-rails, then from said bars through the earth back to the generator; the earth
alone being used to complete the circuit from the metallic bar nearest the point on
the track where the car is at that time located to the dynamo or generator, regardless
of the fact whether at the time the car is in motion or remaining stationary.
In electric-railways, as ordinarily constructed, it is usual to place a conducting wire
in electrical connection by the side of, or underneath, the track-rails so as to form
a complete metallic circuit through the entire system, but this construction is open
to the objection that it is expensive to build as well as unreliable in use.
trolley-
As represented in the drawing, A designates the over-head conductor or
wire of an electric railway, of a common and well-known construction, and B the
track-rails of the same; said wires and rails-when considered by themselves-form
no part of my invention.
designates the bars, or other forms, of metal or other material possessing suitable
electric conductivity, driven or otherwise inserted into the ground in proximity to,
and substantially in line with, the tracks B; said bars are connected, by means of
wires or other electrical conductors, D, to the track-rails B, and said connections
should be in electric contact in order to insure a proper operation of the circuits.
The electric current from the dynamo or generator is conducted to the motor on
the car by means of the over-head wire in the ordinary manner, and from the motor
the current passes-through the car-wheels-into the track-rails at the point whereon
said car-wheels at that time have their bearing; from the track-rails the current is
conducted, through the nearest conductor D and bar C, into the earth; the latter
conducts the current back to the generator and thereby the circuit is completed ;
and it is obvious that-the point of contact of the car-wheels with the track-rails
being constantly shifting, by reason of the movement of the car on the tracks-the
length of the circuit will be constantly increasing, or diminishing, correspondingly to

page_text: the direction in which the car is being moved-the increase of length occurring
when the car is being moved away from the generator, and the decrease when the car
is being moved in an opposite direction, and it will be observed that the variations
in the length of the circuit will be produced automatically by the travel of
the car.
I am aware that telegraph lines have heretofore been constructed with electric
conductors inserted in the earth at points where the terminals of the circuit were
located, but in such constructions the length of the circuit has not been automatically
variable, a manipulation of switches being required to vary the length of the circuit;
this earlier construction forms no part of this invention.
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:
In an electric railway comprising an over-head conductor, or trolley-wire, a motor-
car provided with electrical conductors by which the electric current is carried into
the inotor and thence into the track-rails, a series of electric conductors fixed in
the ground in proximity to the track-rails and connected to the latter by means of
electric conductors, whereby a constantly-varying length of the electric circuit is
automatically effected, substantially as described.
Dated this 9th day of December 1890.
HERBERT J. ALLISON,
Agent for the Applicant.