Improvements in the Closed Conduit System of Electric Railways.
Year: 1896

page_text: Date of Application, 15th Oct., 1896
Complete Specification Left, 15th July, 1897--Accepted, 21st Aug., 1897
Improvements in the Closed Conduit System of Electric Railways.
NIGEL HARINGTON BALFOUR, Engineer; of Belton Camberley in the County of
Surrey England and EDWARD WYTHE SMITH, Engineer, of 66 College Street,
Chelsea in the County of Middlesex England do hereby declare the nature of this
invention to be as follows:-
Our invention relates to those places in an Electric Railway where an overhead
trolley system cannot be employed.
To carry out our invention we form a suitable underground conduit in which one
of the feed wires (hereinafter called for distinction the "positive conductor") is
enclosed. We also arrange a small car (hereinafter called the "contact car") to
run in this conduit. The "contact car "carries a suitable collector or collectors
to form Electrical connection between the "positive conductor" and a feed rail:"
This feed rail is divided into sections, insulated each from the others, correspond-
ing to and in connection with the sections of an exposed feed rail (hereinafter called
the surface feed rail") on the surface of the ground.
The car or coach (hereinafter called the "coach") carries suitable collector or
collectors to form Electric connection between the surface rail and the "coach"
motor. The Electric circuit is completed either (1) through the "coach" wheels,
to the rails thence to the negative conductor or (2) by a second surface rail in con--
nection with the negative conductor.
We arrange two electro magnets: one, on the "contact car," with its poles,
upwards, the other, fixed to the "coach" with its poles downwards, so that in the
normal condition the poles are in proximity and unlike poles are opposed. The..
attraction between these two magnets propels the "contact car" keeping it in a
constant position with regard to the "coach."
may be
Either the electro magnet on the "contact car" or on the "coach" may
dispensed with by replacing it by an iron armature.
The electro magnet on the "contact car" is excited by being Electrically con->
nected to the collectors on the "contact car."
The electro magnet on the "coach" is excited by a current obtained from"
accumulators carried in "the coach." We keep these accumulators charged by
passing through them the current or part of the current which actuates the motor.
In order that, should the "contact" car by any means be left behind in the
conduit, the "surface feed rail" shall not remain "live" we arrange the collectors
on the "contact car" with the electro magnet so that Electric connection is only
made when the electro magnet is attracted by the electro magnet on the "coach.",
Dated this 10th day of October 1896.
NIGEL HARINGTON BALFOUR.
E. WYTHE SMITH.

page_text: Improvements in the Closed Conduit System of Electric Railways.
NIGEL HARINGTON BALFOUR, Engineer, of Belton Camberley in the County of
Surrey England and EDWARD WYTHE SMITH, Engineer, of 66 College Street
Chelsea in the County of Middlesex, England, 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:-
To carry out our invention we form a suitable conduit in which one of the con-
ductors (hereinafter called for distinction "the positive conductor") is enclosed.
We also arrange a small car (hereinafter called the "contact car") to run on a
suitable track in this conduit. The "contact car" carries a suitable collector or
collectors to form Electrical connection between the "positive conductor" and a "feed
rail." This feed rail is divided into sections, insulated each from the others, corre-
sponding to, and in connection with, the sections of an exposed feed rail (here-
inafter called the "surface feed rail") on the surface of the ground.
We employ a car or coach (hereinafter called the "coach") fitted with any of the
usual arrangements of motors and regulating devices. We arrange suitable collec-
tor or collectors of any known construction to form electric connection between the
"surface feed rail" and the coach motor circuit. We complete the electric circuit
either (1) through the coach wheels to the rails thence to the negative conductor
or (2) by a second surface feed rail in connection with the negative conductor.
On the coach, above the conduit, we arrange an electromagnet, with its poles
downwards, the armature of which is carried by, or forms part of, the contact car.
The attraction between this electromagnet and the armature keeps the contact
car in a fixed position relatively to the coach.
We construct the contact car so that electric connection between the positive con-
ductor and the feed rail is made only when the armature on the contact car is
attracted by the electromagnet on the coach.
This we attain by arranging the armature so that it can move vertically under
the action of the electromagnet and thereby actuate collectors on the contact car.
We excite the electromagnet carried by the coach by means of accumulators on
the coach.
Referring to the drawings:-Fig. 1 is a longitudinal section of the con-
duit K K K K showing the contact car part in elevation and part section.
Fig. 2 is a transverse section of the conduit K K K K showing the contact car
end view.
Fig 3 is a plan section of the conduit K K K K showing the contact car part in
plan and part section..
In the various figures like letters are used to denote corresponding parts.
CC is the contact car.
A A forms the armature of the electromagnet M.
F F F F is the "feed rail" divided into sections corresponding with and electri-
cally connected to sections of the "surface feed rail" S S S S.
The connections between the "feed rail" and the "surface feed rail" are not
shown in the drawings.
iiii indicates insulating material.
RR are thé, rails on which the wheels W W of the contact car run. For con-
venience we prefer to 'arrange the. rails R R to form the positive conductor and the
wheels W W to form the contact between the contact car and the positive conductor.
When a positive conductor separate from the rails R R is employed provision must

page_text: be made on the contact car for a collector or collectors to make connections
between the contact car and the positive conductor.
II are insulators which support the rails R R.
On the contact car collectors QQ are arranged so that when the armature A A
is lifted by the attraction of the electromagnet M the collectors make contact with
the feed rail f f. Should the contact car be left behind in the conduit the
armature A A drops and the connection between the feed rail and the contact car
is broken.
The loads W W are to partly counterbalance the armature A. A but are
insufficient to raise it without the attraction of the electromagnet M.
The main electric circuit is as follows:-From the positive terminal of the
generator to the "positive conductor" thence to the contact car by the wheels W W.
From the contact car by the collectors Q Q to the "feed rail" thence to the
surface feed rail and by the collector carried by the coach to the coach motor
circuit thence by the negative conductor to the negative terminal of the generator.
The coach is not shown in the drawings neither are the rails on which the coach
runs, and the collector, which makes electric connection between the surface feed
rail and the coach motor circuit.
We prefer to make the sections of the feed rails equal to or less than one half
the length of the coach in order that at no time is any part of the surface feed rail
live which is not covered by the coach.
Fig. 4 indicates diagrammatically the electrical circuit of the electromagnet M.
BB are accumulators, for exciting the electromagnet M.
N is a switch for closing the magnet circuit.
rris a resistance.
To keep the accumulators charged we pass through them the current or part of
the current which actuates the motor. This current enters the accumulator
circuit at and leaves at y and is controlled by the switch L.
We do not confine ourselves to the exact details herein described as the same
may be modified without departing from the nature of our invention.
Having now particularly described and ascertained the nature of our
invention, and in what manner it is to be performed, we declare that what we
claim is:
1. In the closed conduit system of electric railways a "contact car" in which by
the motion of an armature carried by or forming part of the contact car actuates a
collector or collectors so that electric connection is made between the "feed rail"
and the "positive conductor" only when the said armature is attracted upwards,
substantially as and for the purpose described.
2. In the closed conduit system of electric railways the employment of an
electromagnet M. carried by the coach and energised by accumulators B B which
accumulators are charged by the current, or part of the current, which actuates the
motor, substantially as described with reference to Fig. 4.
Dated this 15th day of July 1897
NIGEL HARINGTON BALFOUR.
E. WYTHE SMITH.