Improvements in Electric Railways.
Year: 1896

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c., Act, 1883), as allowed
by the decision of the Comptroller General of the 21st day of June 1897.
Date of Application, 19th May, 1896-Accepted, 20th June, 1896
(AMENDED).
[Communicated from abroad by EDWARD HIBBERD JOHNSON, and ROBERT
LUNDELL, both of No. 527 West 34th Street, New York City, New York,
United States of America, Electricians.]
Improvements in Electric Railways.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, 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:
This invention relates to that type of electric railways in which the propelling
current is taken from sectional trolley conductors automatically connected to a main
supply conductor by the presence of a motor car and again disconnected therefrom
as the car passes on its journey.
This invention has for its objects: First, the rendering of the operation of such
a system absolutely safe as regards disconnecting the sectional conductors from the
main supply conductor after a car or train has passed; and second, the reliability
of current supply when such is required to propel the car or train, and particularly
the certainty of not losing the propelling current when running at very high speeds
in either direction upon the same track.
These objects are accomplished by the apparatus hereinafter described.
In the accompanying drawing:
Figure 1 is a diagrammatic view illustrating a section of a single track street
railway, eight sectional trolley or service conductors arranged in two rows parallel
to a current main or supply conductor, electro-magnetic switching devices and
circuit connections between the sectional conductors, the switches, the main supply
conductor and the rails or return conductor; also a diagrammatic view of a street
car showing current collecting devices, car wheels, a motor, a battery, a switch,
circuit connections from the current collecting devices to the switch the battery
and the motor, and circuit connection from the negative end of the battery to the
car axle or return conductor.
Figure 2 is a diagrammatic view illustrating a section of a single track trunk
line railway equipped and operated upon the same generic principle as the street.
railway but differing therefrom in some important details regarding the length
and location of the sectional trolley conductors, the size and capacity of the
battery and the circuit connections appertaining thereto.
Referring first to Figure 1: FW represents a current feeder or main supply
conductor and F, F, F, Fw branch feeders therefrom leading into switch
boxes, not shown on the diagram, and to non-fusible fixed contact points 1, 1, 1,

page_text: All of these conductors and parts should be extremely well insulated,
inasmuch as they are alive at all times. The opposite contact points 1, 1, 1, 1 are
connected through wires 1, 3, 5, and 7 to sectional trolley conductors Se¹, Sea,
Se and So, all of which are only successively made alive when current is required
to propel the car. Sc³, Sc, Sc, Sc are additional se tional trolley conductors
connected by wires w, w, and through low resistance magnet coils to the
track rails or return conductors R and R', the arrangement being such that the
magnet coils of adjacent switch magnets are interconnected by means of the circuits
leading from each sectional trolley conductor Sc², Sc, etc., to the track rails.
These interconnections serve to make the sectional conductors or rails Sc¹, Sc³, Ses
and Sc alive before they are reached by the travelling contact shoe S, no matter
in which way the car be going, the importance of which will be understood by the
description of operation which follows.
which when
The contact shoes S1 and S2 carried by the car are of such length that they
will bridge the spaces between two sectional conductors or rails. The contact
shoe S¹ is connected by means of wire to the lever of a switch S
closed completes connection through wire to the positive pole of a battery B
and through wire to to motor M as shown. The other terminal of the motor is
connected through conductor e to contact shoe S, and the negative pole of the
hattery B is connected through wire directly to the car axle and return.
conductors R and R¹.
The operation of the apparatus shown in Figure 1 is as follows:
Suppose that all the electro-magnetic switchies are open, and that the motor-man
is just closing the switch Sw. A current will then flow from the positive pole of
the battery through wire to" to switch Se, through resistances and conductor e,
through the motor M and wire 2012 to contact shoe S2 and hence to sectional trolley
conductor Sc, thence by wire wo through a coil around the switch magnet M and
also through a coil around switch met M energizing these two magnets and
finally to track rails R and R', car wheels and negative pole of the battery. The
instant this current begins to flow and before the car has had time to start, the
switch levers p² and p³ will close connection between the branch feeders Fu², Fu
and the sectional trolley conductors Sc³ and Sc³ as shown in the drawing. Owing
to the dominating E.M.F. of the current feeder or main the current will now flow
as follows; from current feeder or main FW to branch feeder Fu2 through switch
contacts and 13 and wire w³, to sectional trolley conductor Sc³, hence to contact
shoe S¹ and through wire to switch Sw where the current divides into two
parallel circuits, one flowing through wire to the battery B (charging the
saine) and thence through wire 3 to car axle and return conductor: the other
circuit being by wire to through the motor M, conductor contact shoe S,
sectional conductor Sc, wire and through the coils of magnets M2 and M³ in the
same direction as before to track rails R R or return conductor. It will thus be
seen that the coils of the magnets M2 and M³ are in series with the motor M, and
that in consequence the switch levers p2 and ps will remain closed as long as the
propelling current flows through conductor w. If the car be moving from right
to left, it will be evident at a glance that the sectional conductors Se and Sc are
made alive in advance of the contact shoe S¹; but it remains to be seen if this
holds true when running in the opposite direction. Suppose the car starts from
the position shown and moves to the right instead of to the left. All connections
will then remain undisturbed as long as the contact shoe S2 is still upon the
sectional conductor Sct. But when the shoe S2 closes contact with sectional
conductor Sc² and finally breaks contact at Sc¹ the propelling current will simply
be shifted from wire w to wire . This, however, energizes magnet M instead
of magnet M³ and magnet M remains undisturbed, leaving the branch feeders Fu
in connection with Sc. As the shoe S¹ now approaches sectional conductor Sc¹
the lever p¹ will have closed connection between the branch feeder Fw and the
sectional conductor Sc', thus illustrating that the system of interconnections
between switch magnets is adapted to work both ways.

page_text: Upon studying the diagrain in Figure 1, it will be understood that the maximum
time allowed for each magnet to close is equal to the time the car takes to travel
the distance between the sectional conductors Sc² and Sc¹. It will also be noted
that the high potential sectional conductors Sc', Se, Se' and Sc' are in direct
connection with the contacts 12, 13, 1' and ' in the switch boxes without any of the
coils around the magnets being included in circuit, so that in case the insulation of
one of these sectional conductors should become impaired the leakage current
cannot hold the magnet closed and therefore cannot keep the conductor alive after
the car has passed.
In the street railway system just described, the potential difference between the
feeder and track rails has been supposed to be about 500 volts. The sectional
conductors are placed in the road-bed with their upper contact surfaces slightly
higher than the pavement and as well insulated as practicable from the ground.
To minimize leakage in wet weather they are made as short as possible, and to
prevent any sectional conductor from being alive in front or after the car they are
placed at such distances apart that the platforms of the car will safely cover both
the conductor which is doing service and the one which is made ready for service.
The battery is supposed to be of an E.M.F. approximating that of the line, so that
it will always be fully charged and ready to do service when called upon. It
may also be of such capacity as to be able to propel the car for short distances
across turnouts, crossings, switches, etc., where the electric equipment of the road-bed
would present natural difficulties. The battery will thus propel the car indepen-
dently of the station current by closing the switch Sw and also another switch not
shown in the drawing, which switch will close a connection between wires w12 and 13
and which may also be so arranged that it will break connection between switch Sw
and the contact shoe S¹.
Upon examination of Figure 2, it will be noted that the sectional conductors or
rails are made much longer and that the conductors or rails Sc², Sc and Sc are
placed on the outside of the track rails, the object of so placing being to obtain
additional safety against leakage from the high potential rails Sc¹, Sc³, Scs. These
rails are to be supported on good insulators, which in turn are supported on the
cross-ties. Suppose for illustration that the difference of potential between feeder
and return rails is 1000 volts and that the locomotive shown in diagram is capable
of exerting a maximum power of 1000 H.P. or 750 K.W. Under these conditions,
it would of course be absurd to employ a battery to move the train. The battery
in this case is therefore of a capacity sufficient to close the electro-magnetic
switching devices and to keep the same closed in case the locomotive should happen
to take an unusually small current. The arrangement of circuit connections is,
however, such that after the original closing the main current operates the electro-
magnetic switches and at the same charges the battery.
The operation is as follows:---
Supposing the locomotive is at rest and that all the switches are open. Upon
closing the switch Sw a current will flow from the positive pole of battery B
through wire ull to switch Sw, hence by wire w12, contact shoe S2 to sectional
conductor or rail Sc, by conductor w through a coil of magnet M2 and also
through a coil of magnet M³, and finally by track rails, car axle, wire la to the
negative pole of the battery. The magnets M2 and M³ are now energized and
levers p2 and p³ have established connection between the branch feeders F2, Fw³
and the sectional conductors or rails Sc³, Sc' as shown in the drawing. The
current now flows as follows; from branch feeder Fu by wire w5, sectional
conductor or rail Sc³, contact shoe S¹, wire wo through the motors M by wire wo
through starting resistances and switch Sw where it divides itself, one part of the
current flowing by way of wire w12 to shoe S2, sectional rail Sc', wire w around
both magnet coils as at the instant before and finally to track rails R and R¹ back
to the generating station. The other part of the current flows by wire " through
the battery B charging the same, and by wire w¹³ to car axle CW and track rails.
To fully appreciate the automatic charge or discharge of the battery as the case

page_text: may be, it will be necessary to illustrate the operation with a few figures. Suppose
the battery B consists of 3 cells of large ampere capacity. The EM.F. of
discharge will then be about 10 volts, whereas the counter E.M.F. at charging will
be about 5x2.5 12.5 volts. Assume the sum of all the resistances included
in the circuit 12, contact shoe S, sectional conductor or rail_Sc³, wire wr, two
electro-magnet coils M M³ to the negative pole of the battery B to be 03 ohms.
Upon closing the switch, the battery will then send a current of = 200 amperes
10
.05
through this circuit. In case the current from the main supply conductor flowing
through the notors and starting the same should happen to be 200 amperes, no
current will flow through the battery nor will any appreciable amount of current
flow through the same until the current has increased to 250 amperes when the
E.M.F. at the battery terminals has risen to 12.5 volts. But if the motors should
take about 500 amperes about half of this current will flow through the battery
charging the same. At the same time, if the train should run down a grade and
happen to take so small a current that there is danger of not having sufficient
number of ampere turns around the magnets to keep them properly energized, then
the battery will at once make up the difference between 200 amperes and the
current taken by the motors.
To illustrate the importance of the interconnections between the magnets, let
us assume that the locomotive shown in Figure 2 is moving from left to right at a
speed of 60 miles per hour or 88 feet per second. As the shoe S is travelling
over the sectional conductor or rail Sc, and shoe S2 is leaving sectional conductor
or rail Se and commencing to travel upon conductor or rail Se, the current is
shifted from wire w to wire w and the magnet M2 is in condition to close its
switching lever p. But when the shoe S leaves rail Se' the magnet M² must be
closed and conductor or rail Sc³ must be alive or the propelling current would be
broken at the end of rail Sc. Now, if the magnets are made to safely close in
one-half a second, it follows that the distance D, see Figure 2, must be about
44 feet. Should the train move at still greater speeds, it will be necessary either
to construct electro-magnets that will operate in less than one-half second or to
make the sectional rails longer, or to increase the length of the contact shoes.
Having now particularly described and ascertained the nature of our said
invention and in what manner the saine is to be performed, we declare that what
we claim is :-
1. In an electric railway a system of permanent or continuous interconnections
between the electro-magnetic switches and sectional trolley conductors, the arrange-
inent being such that each electro-nagnetic switch is given a certain time
allowance to close it before it is called upon to transmit the propelling current no
matter which way the car or train be moving as hereinbefore described.
2. In an electric railway system a current feeder or main, a series of sectional
trolley conductors, electro-inagnetic switches for connecting said sectional
conductors to the current feeder or main in sequence as a car or vehicle moves
over them in either direction, a battery and a motor carried by the car for
operating the switch electro-magnets and propelling the car; said electro-magnets
being permanently or continuously interconnected in series relation so as to
connect up the sectional conductors to the feeder before the propelling current is
connected in circuit with the motor.
3. In an electric railway system a current feeder or main, a series of sectional
trolley conductors, electro-magnetic switches for connecting said sectional
conductors to the current feeder or main as the car passes over them; the
electro-magnets being permanently or continuously interconnected with each other.
and the sectional conductors so that each of the conductors which is designed to
carry the propelling current to a propelling motor carried by the car shall be
connected to the current feeder before it is connected to the motor, the connections

page_text: and arrangement being such that the car may run in either direction with equal
facility.
4. In an electric railway system a current feeder or main, two rows of sectional
trolley conductors, permanently or continuously interconnected electro-magnetic
switching devices, in combination with a return conductor or rail located between
said rows of sectional trolley conductors.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.