Improvements in Apparatus for Controlling Electrio Motors.
Year: 1896

page_text: Date of Application, 13th Oct., 1896-Accepted, 27th Feb., 1897
[Communicated from abroad by ELMER AMBROSE SPERRY, of Cleveland,
County of Cuyahoga, State of Ohio, United States of America.]
Improvements in Apparatus for Controlling Electrio Motors.
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:-
My invention relates to systems of control for electric motors, and it consists in
organization of circuits and devices for manipulating such circuits whereby the
motor may be either supplied with current from a source of electrical supply so as
to operate as a motor; or one or more of its field coils may he energized from the
said source of supply while the terminals of the motor are changed so as to operate
as a generator when the main or any subsidiary circuit is closed, and it farther
consists in the employment of automatic means for transferring the coil or coils
upon the motors from one to another source of electrical supply or potential
whereby they may derive energy from one automatically upon the failure of the
other or others.
To this end devices are shown, principally in diagram, which exhibit one method
of carrying out my invention. These are fully described in the specification,
pointed out in the claims and shown in the drawings, in which:
Fig. 1 is a diagrammatic view of the controller showing the three sets of contacts
consisting of the center row, which is usually the stationary contact, and a set of
contact plates upon both sides thereof, those on the left being shown as entirely
isolated from the circuit while some of the set of contact plates on the right are
shown in contact with the first named or central set of contacts.
Fig. 2 illustrates a diagrammatic view of the motor, windings and circuits
connected thereto.
Figs. 3 and 4 are diagrams of the circuit connections when the motor is normally
operating as such and deriving its current from a trolley or other source of
electrical supply, the motor running oppositely in the two figures.
Figs. 5 and 6 are diagrams of the circuits of the motor when the controller
stands in its off position, but after the elements have been reversed from their
respective positions, shown in Figs. 3 and 4, so as to act as motors, the circuit
through the main field coil being broken, but that through the shunt coil being
closed to the source of electrical supply and ground or equivalent return connection.
The motors are shown as running oppositely in the two figures. It will be
understood that the armatures in these figures are open-circuited.
Figs. 7 and 8 represent the controller still in position as shown in Fig. 1, but
where the trolley or other connection to the source of electrical supply has been
broken, and where the connection of the coil of high resistance of the said motor
has been automatically transferred to the armature circuit and receives its current
supply therefrom, the main field coil being still out of circuit the armatures running
oppositely in the two figures.
Fig. 9 is a detail view of the reversing switch.
Like letters and numerals of reference indicate similar parts throughout the

page_text: A represents the armature which revolves in the fields B', receiving magnetization
from the coils F, F, which constitute the main field coils of the machine, and also
from coils, which constitute the field of high resistance of the machine.
Suitable circuit wires are shown connecting and leading to these coils and to the
commutator C.
If the machine is to be operated as a motor, the set of contact plates shown in
Fig. 1 to the left will be brought in contact with the middle set by the changing
in position or movement of either of the sets of contacts as will readily be under-
stood; but for the purpose herein it is preferred that the central row remain
stationary, and that the elongated plates on either side thereof constitute the
moving sets hereinafter referred to. Under these conditions the current emanating
at D would flow to contact T, plate 9 down to the connected plates, whichever be
the lower in contact with the central row, for example plate 10, thence the current
would flow to contact 11 down through the resistances R, R, to the lower contact
which is coupled by a wire 12 to contact 13, thence to contact plate 14, cross
connected to plate 15, contact 16, commutator brush 17, commutator C, brush 18,
contact 19, plate 20, plate 21, contact 22, field F by wire 23, to the ground G by
wire 24. When, however, the moving parts of the controller are turned in the
opposite direction so that the center row of contacts shall be in the position and
connection as shown in the drawing, it will be seen that the circuit relation of the
field and armature have been reversed in readiness for the motor to act as a
generator whenever necessary or whenever the proper circuit connections are
closed, and it will be further seen that the said source of electrical supply D will
now operate to supply the field of high resistance f, the circuit connection of
which may be traced as follows: The current arriving at contact T flows out on
contact plate 25 to wire 26, magnet M, wire 27, to contact plate 28, thence to
contact 29, wire 30, field fand the wire 31 to the ground G. It will be noticed
that the wire 27 receives a connection 32 to armature lever or contact L pivoted
at L' and provided with a laterally projecting pin L" which is made to co-operate
with the beveled end and top edge of the lifter O. It may be stated that either
the magnet M or its armature L moves with the controller, and the lifter O
reniains stationary or the lifter may move and the other parts remain stationary,
either serving the purpose hereinafter specified. Co-operating with the armature
or lever L or contact thereon will be found the contact 33 connecting by wire 34
to the armature plates 35 and 36, the current flowing in one of these to the
armature, the particular one being determined by the position of the contacts 16
and 19.
The diagrams in Figs. 5 and 6 are given to illustrate more clearly the circuit
connections which have just been traced.
In Fig. 9 is shown a detail view of the reversing switch. The brushes 16 and 19
are mounted on an insulated support and are adapted to be moved up and down by
means of lever P so that they may engage with contacts 35 and 39 as shown, or
with 36 and 39. By tracing the connections through the armatare and field, it
will be seen that the relations are reversed whenever the brushes are shifted from
the position shown to that described above.
It will be seen that the magnet M, so long as the current from the trolley or
other source persists, will hold its armature L out of contact with terminal 33, as
shown in said Figs. 5 and 6. Should, however, the magnet M lose its magnetization
for any cause whatever, the armature L will fall to its position shown in dotted
lines in Fig. 1, whereupon the circuit relations shown in Figs 7 and 8 will be
obtained and the high resistance field coilf will receive current from the armature A,
which is now coupled as a generator, the current flowing in the circuits as follows,
see Fig. 1 Current emanating at brush 17, will flow to contact 16, plate 35,
wire 34, contact 33, lever L, wire 32, wire 27, contact plate 28, contact 29, wire 30,
field f, wire 31 to the ground contact G which is usually coupled to wire 37 to
shunting contact S, plate 38, to plate 39, contact 19, brush 18, commutator C, to
the point of starting. Thus it will be seen that the coil f continues to receive

page_text: energy, but froin a different source, the change having been effected automatically,
and from any cause, as for instance, the failure at the source of supply D.
The mechanical shunt S consists of a piece of metal provided with fingers which
are adapted to engage with the contacts 38 and 41, which are mounted on the
right-hand side of the moving cylinder. The contact S being stationary, it only
engages with the contacts 38 and 41 at stated intervals. Its object is to form a
shunt around the brake-magnet K for a predeterioined interval, so that the motor C,
when converted into a generator, has time to build up its electro-motive force
before the load (which in the present instance is the brake-magnet K), is included
in circuit therewith.
Assuming that the controller cylinder is moved to the left with respect to the
vertical row of brushes, so that the circuit between the shunt S and the contacts 38
and 41 is interrupted, the circuit will be as follows:
The current, emanating from the commutator brush 17, will flow to contact 16,
to plate 35, by cross-connection to plate 40, brush 22, by wire 23 to field F, to
ground G, thence to ground G', brake-magnet K, brush B, to contact 41, by cross-
connection to contact 42', assuming that the contacts have been moved thus far to
the left, to brush 11, through resistance R, by wire 12, shown in dotted lines, to
brush 13, contact 38, by cross-connection 43 to contact 39, to contact 19, through
the flexible lead to commutator brush 18, to commutator C, the point of starting.
During this time the trolley may be receiving current from the source of
supply D and supplying it to the high-resistance field; or the contact 25 may be
short, so that the trolley will be disconnected from the field f as soon as the central
row of contacts advances toward the right. The same effect will be produced if
the contact 28 is short, but this is a matter of detail, and not essential to the
invention.
Assuming that the contacts 25 and 28 are as shown, the circuit from the trolley
would be as follows: To brush T, to contact 23, by wire 26, through the magnet M,
by wire 27 to contact 28, to brush 29, by wire 30 to field, by wire 31 to
ground G.
With the circuits arranged as above it will be seen that the field F is supplied
from the armature A of the generator; and that the high-resistance field is
supplied from the main source of supply D.
It for any reason the current from D fails, and the generator is employed for
braking, or is connected as shown in Figure 1, the armature L drops and establishes a
circuit through the bigh-resistance field / from the cummutator C (the circuit being
described in the preceding paragraph.
It will be seen that the armature L of the maguet is always maintained in
the position shown by means of the lifter O when the motor is employed for power
purposes.
One point connected with the automatic return of the lever L to its position in
proximity to the magnet M will he readily understood, the bevelled extremity of
the lifter O is so positioned with reference to the moving contacts that the lever L
is held out of contact with terminal 33 whenever the motor is being normally
operated as such, and is held in contact while removing such motor from circuit
until the circuit relations through the magnet M are established, whereupon the
upper edge of the lifter O has passed from under the pin L" and the magnet M
forms the total support for the lever L which will, from that time on, hold the same
out of contact with terminal 33 unless the current from the supply should cease and
it became necessary to establish relations with the new source of supply, as has
been fully pointed out.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, as communicated to ine
by my foreign correspondent I declare that what I claim is:
1. In an electric controller, a source of electrical supply, a series electric machine,
an independent field coil of high resistance from such machine, the controller

page_text: adapted to assume a position wherein the main circuits are open, in combination
with contacts so located in the controller that at the above position of the
controller the source of supply is connected with the field coil of high resistance.
2. In an electric controller a source of electrical supply, a series electric machine,
an independent field coil of high resistance for such machine, the controller adapted
to assume a position wherein the main circuits are open, contacts so located in the
controller that at the above position of the controller the source of supply is
connected with the field coil of high resistance, in combination with means
responsive to an electric current for holding an electric circuit open.
3. In an electric controller, a soures of electrical supply, a series electric machine,
an independent field coil of high resistance for such machine, the controller adapted
to assume a position wherein the main circuits are open, contact so located in the
controller that at the above position of the controller the main source of supply is
connected with the field coil of high resistance, in combination with means responsive
to an electric current for transferring the high resistance field coil to the said main
circuit.
4. In an electric brake system, the combination of means for placing the motor
in operative connection with a source of electrical supply so as to be driven as a
motor, contacts for connecting the source of electrical supply to an auxiliary
field coil of such machine, a reversing ewitch for reversing the relation of armature
and field, and contacts and brushes for coupling them as a generator to an electric
circuit.
5. In an electric brake system, the combination of means for placing the motor
in operative connection with a source of electrical supply so as to be driven as a
motor, contacts for connecting the source of electrical supply to an auxiliary field
coil of such machine, a reversing switch for reversing the relation of armature and
field, and contacts and brushes for coupling them as a generator to an electric
circuit and including in said circuit a regulating device.
6. In an electric brake system, the combination of means for placing the motor
in operative connection with a source of electrical supply so as to be driven as a
motor, contacts for connecting the source of electrical supply to an auxiliary field
coil of such machine, a reversing switch for reversing the relation of armature
and field, contacts and brushes for coupling them as a generator to an electric
circuit, and means for automatically coupling the auxiliary field coil to the
armature circuit whenever the flow of current in the main source falls below a
predetermined amount.
7. In an electric brake system, the combination of means for placing a motor
in operative econection with a source of electrical supply, contacts for including
the source of electrical supply with an auxiliary field coil only of the motor or
motors, a short-cireniting device for cutting out the brake magnets at a pre-
determined time, a reversing switch, and means for opening the short circuit
around the brake magnets.
8. In an electric brake system, the combination of a motor having main anad
auxiliary field coils with contacts for including the auxiliary field in the trolley
circuit when the motor is not propelling the car.
9. In an electric brake system, the combination of a dynamo electric machine
for propelling and braking the vehicle, an auxiliary field coil for maintaining the
field magnetization, and automatic means for shifting the connections of the
field coil from the inain source of supply to the armature of the dynamo electric
machine.
10. In an electric motor, for propelling and braking the vehicle, the combination
of main and auxiliary field coils, and means for connecting the auxiliary field coil
to the main source of supply or the motor armature.
11. In an electric motor, for propelling and braking a vehicle, the combination
of main and auxiliary field coils, and current-controlled means for shifting the
connections of the auxiliary field coil from the source of supply to the armature of
the motor upon failure of said source.

page_text: 12. In an electric brake system, the combination of a controller for regulating
the supply of energy to the motors and the brakes, an auxiliary field coil on the
motor for maintaining a certain amount of field magnetization, contacts for
including this coil in circuit with the source of supply, and a current-controlled
device for shifting the connections from one source to another upon failure of the
first.
13. The combination of an electric motor having main and auxiliary field coils,
means for reversing the relation between the armature and fields, and automatic
means for shifting the connections of the auxiliary field coil from one source of
supply to another.
14. In a controller for electric motors, the combination of contacts for regulating
the supply of energy to the power side of the system, contacts for regulating the
supply of energy to the brake side of the system, brushes and connections for
establishing various combinations in the circuit relations, certain of the brushes
making contact with one side of the system when the circuit is interrupted, and
automatic means for changing the connections of the auxiliary field coils from the
source of supply to the armatures of the motors upon failure of the said source.
15. The combination with a dynamo electric machine, of main and auxiliary
field coils, contacts for establishing circuit relations between the source of supply
and the dynamo electric machine, contacts for establishing circuit relations between
the dynamo electric machine and brakes, and current controlled means for auto-
matically changing the auxiliary field coil from the trolley circuit to the armature
of the dynamo electric machine.
16. In an electric brake system, the combination of contacts for regulating the
supply of energy to the brakes, brushes in engagement with certain of the contacts
in the "off" position of the controller, and automatic means for changing the circuit
relations at the time the coutroller is in the off position.
17. In an electric brake system, the combination of a controller for regulating a
motor used to propel or brake a vehicle, main and auxiliary field coils on the motor,.
automatic means for changing the connections of the auxiliary field coil, and means
for interrupting the circuit relation of the auxiliary field coil and armature when
the motor is propelling the car.
18. In an electric brake system, the combination of a controller for regulating
the supply of current to a dynamo electric machine when propelling or braking a
car, main and auxiliary field coils on the dynamo electric machine, and automatic
means carried by the controller for shifting the connections of the auxiliary field
coil from the trolley to the armature of the dynamo electric machine.
19. In an electric brake system, the combination of a dynamo electric machine
having main and auxiliary field coils, contacts for including the auxiliary field coil
in either the trolley or armature circuit, and a shunting device for the brake
magnets for preventing their acting at a certain time.
20. In an electric brake system, the combination of a motor having main and
auxiliary field coils, a controller for regulating the energy of the system, current
controlled means for including the auxiliary field coil in circuit with the source of
supply or the motor armature, and a device for momentarily shunting the brake
maguets before the current from the motor armature is supplied thereto for the
purpose of braking the vehicle.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, W.C., Agents for the Applicant.