Improvements in Electric Railway Systems.
Year: 1898

page_text: Date of Application, 15th Nov., 1898-Accepted, 7th Jan., 1899
COMPLETE SPECIFICATION.
Improvements in Electric Railway Systems.
I, JOHN MCLEOD MURPHY, of Torrington, in the County of Litchfield and State
of Connecticut, United States of America, Electrician, 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 improvements in surface contact electric railway
systems and particularly comprehends an improved rotary transformer means for
creating and maintaining the local or car-carried electric source of energy, at a
uniform current of high electro motive force for maintaining the lights, heaters
etc., on the car, as also for energizing the electro magnetic switch mechanism for
cutting in the contacts (engaged by the transmitter) with the main or feeder
current.
In the ordinary construction of motor transformer it is evident that to convert
current of one potential to a current of a different potential, that the ratio of
the electromotive force between both armatures with the same field excitation
and speed; will not be in direct proportion to the armature turns, but there will
be a loss in electro motive force due to electrical and mechanical losses.
Now, if it were desired to build such a motor transformer as stated; to charge
storage batteries from a source of energy, and also wish to use this same trans-
former to supply energy at the same potential as the said source of energy, when
such source of energy is removed, with the means now known such motor trans-
former could not be adapted to perform the work desired.
Primarily this invention seeks to provide a very simple means for charging the
ratio of the induced electro-motive force in both armatures of the transformer,
whereby a higher electro-motive force in the low potential armature in circuit
with the storage batteries, is produced, which in becoming equal or superior to the
storage batteries, will cause such batteries to cease supplying current to the low
potential armature and the high potential armature, and then take current from
the high potential source of current and thereby rotate the two armatures, the
improved means hereinafter described also serving to create current sufficient to
supply magnetising force which, added to that already due to the low potential
winding, will cause the low potential armature to generate a voltage greater than
that supplied by the battery and so not only take no current from the said battery
but charge it.
In the drawings:-
Figure 1 illustrates diagrammatically my improvements, the several parts being
adjusted to bring L P armature in use as a motor, and the HP armature as a
generator.
Fig. 2 is a similar view, the parts being adjusted to make the HP armature the
motor and the L P armature the generator, the controller being shown in dotted
lines in position for shunting the main or feed circuit to the car motor trolley.
Figs. 3 and 4 illustrate modified arrangements of the transformer devices
hereinafter referred to.

page_text: Referring to the detailed arrangement of my improvements, S B indicates
storage batteries; F L P the low potential field winding; FHP high potential
feed winding; L P low potential armature; II P high potential armature, all of
which may be of any well known' construction.
11 indicates the controller in the high potential circuit of the transformer;
12 the first contact for the controller connected to the trolley 12ª; 12 one of the
trolley contact rails; 12° low resistance or heavy wire winding of the switch S;
15 the fine wire or high resistance winding of switch S.
16 indicates the return of the fine wire winding 15; 16 the feed wire to
switch $; H the heater; L lamps, all of which are in the high potential circuit
of the transformer.
Assuming that there is a ten-cell storage battery giving an electro motive
force of 20 volts, and it requires an electro motive force, say of 22 volts, or such
excess as is necesssary to overcome the electrical and mechanical waste or resistance
in charging.
Assuming the battery as being charged, part of the current of 20 volts potential
passes in the direction of 1, to F L P in the direction of 2, and back to battery.
Another portion of the current passes in the direction 4 to L P armature and
back in the direction of 3 to the battery, while another portion of the current
passes by the way of 5 to FHP and back through 6 and 3 to battery.
Armature HP is mechanically connected to L P armature and revolves with
it at the same speed, causing an electro-motive force to be induced in H P arma-
ture in the direction and strength proportionate to its field winding and which
assumably is 500 volts, in the direction shown, and makes available a current on
that potential for the desired purposes.
Now, if an electro-motive force giving 500 volts is applied at HP armature,
it is evident that the S B will be still called on to supply current to the L P
armature for the reason that the 500 volts applied at H P armature will be
equal to the induced electro-motive force of that armature, and no current can
pass to rotate the armatures and S B cannot be charged from the high potential
current applied, unless the ratio of the electro-motive force of the two armatures
is changed. This change of ratio I accomplish as follows:
X indicates an auxiliary winding wound about the F L P armatures with an
external source of electro-motive force, the turns of such auxiliary winding being
proportioned and connected in such direction that the current flowing through it
and the resultant magnetising force will be in the same direction as that caused by
winding FL P; this will produce a higher counter electro-motive force in arma-
ture LP which, becoming equal or superior to that of the storage battery causes
the battery to cease to supply current to that armature, and armature H P will
then take current from the 500 volts source of energy which rotates the two
armatures. The current flowing through winding X is, however, of such strength
as to supply sufficient magnetising force which, added to that due to winding F L P
will cause armature L P to generate an electru motive force greater than that
supplied by the battery and thereby not only take no current from such battery
under such condition, but charge it.
When combining my improvements with electric railway systems of the character
stated, the 600 volts generated by the armature, when L P armature is acting as
a motor and H P as a dynamo, is used to operate lamps, heaters etc., and partien-
larly the switch mechanism for shunting the circuit.
In operation when the controller is turned to the first notch contact 12, a 5
potential of 500 volts is available to actuate the switch, the current flowing as
follows:
Starting from armature HP in the direction of 10, to controller 11, to con-
tact 12, trolley T, rail 12b, wire 14, to winding 15 of switch 8, to 15* to return
to armature. This current actuating switch S causes a break in circuit 15 and
closes contacts of the switch to shunt the main current through the switch, the
path of the current then being through the feeder wire, through contacts 18,

page_text: to switch, through contact 12, controller 11, armature HP and by return to
central station.
As, however the armature HP is generating E F equal to that applied by
the feeder the current in the high potential circuit of the transformer is rendered
5 practically nil.
The next movement of the controller will close with the contact 18, which causes
current to pass as follows;
From the feeder, through switch at 18 to contact 12, controller 11,
contact 13, winding X, and return 20. This increases the magnetising force
of F L P, and as LP armature will then act to generate a higher electro-motive
force no current will go through it from battery, and the armature HP will then
take current from the main or feeder wire and operate that end of the machine
as a motor; the other end becoming a generator of sufficient electro-motive
force to charge the batteries.
The car motor can be in circuit with contact 13, or a third contact held in such
relation to the controller as to take current through said controller.
The same result described can be obtained by placing the auxiliary winding X
round FHP as shown in Fig. 3. In this form, however, the direction of the
ourrent in X will be such that its resultant magnetising force will be opposed
to that of F HP and thereby reduce the total magnetism of F H P and causing
a lower counter electro-motive force in HP, allowing it to take current from the
500 volts potential and rotate the armatures at a higher speed than that at which
the current due to the electro-motive force of the battery rotated said armatures,
thereby causing armature L P to produce a higher electro motive force sufficient
to charge batteries.
Both the above described methods can be combined. In such combination two
auxiliary windings X-X are used, one round each field, as shown in Fig. 4,
and both connected in series or in multiple if desired.
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:-
1. An electric railway system, having an electro-magnetic switch for shunting
the feed circuit and initially operated by a source of energy on the car, said
source of energy comprising a rotary transformer having an auxiliary winding
for the field cores in circuit with the high potential armature through the switch
controller for the purposes specified.
2. An electric railway system having automatic circuit-shunting devices
governed by a source of energy on the car, said source of energy including a
rotary transformer having means for creating a surplus magnetising force for the
low potential armature or decrease in magnetising force of high potential arma-
ture, or both, adapted to be brought in line with the main or feeder current when
the controller is set to operate the shunting devices from the car-carried source
of energy for the purposes specified.
3. In an electric railway system of the character described, having automatic
circuit-shunting devices for the sectional conductor, governed by a source of
energy on the car, said source including a rotary transformer having auxiliary
windings about the cores of the low potential armature or high potential arma-
ture, or both, a controller in circuit with the high potential armature of the
transformer, and adapted when moved to its first step to energize
the shunting devices to out in the main ΟΙ feed current with the
high potential armature and when moved to its second step to place
the auxiliary winding in circuit with the main or E M F circuit, whereby
to create a change in the magnetising force to cause the low potential armature
to recharge the battery of the transformer, as specified.
4. In an electric railway system as described, a local source of energy to be
carried on the car for operating the switches to cut in the main or feed current

page_text: with the sectional conductors, said source of energy comprising a rotary trans-
former having an auxiliary winding for creating an increased magnetising force
for the low potential armature, or decreased magnetising force in high potential
armature, or both, and means for cutting in the said auxiliary winding with an
applied current of high potential in inverse direction of the transformer for the
purposes specified.
5. The combination in a system as described of the sectional conductors, an
electro magnetic awitch in the feeder wire having high and low resistance wind-
ings, a trolley, the motor, the controller, the rotary transformer having its high
potential armature in line with the controller, an auxiliary winding for the low
potential armature, or for the high potential armature, or both, said winding
having a controller contact, said controller being arranged when moved to
its first notch to shunt the local or transformer circuit through the trolley to set
the switch and then open up main line current to the high potential armature,
and when moved to its second notch to shunt such main line circuit to the auxiliary
winding and the car motor, all being arranged substantially as shown and for the
purposes described.