Improvements in or relating to Electric Motors.
Year: 1899

page_text: Date of Application, 30th Dec., 1893-Accepted, 29th Sept., 1900
COMPLETE SPECIFICATION.
Improvements in or relating to Electric Motors.
I, HAROLD ROWNTREE, of 76, West Jackson Street, Chicago, County of Cook,
State of Illinois United States of America, Manufacturer, 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 electric motors.
The object of the invention is to provide an electric motor particularly adapted
for use as a hoisting motor for elevators, but capable of general use where
variations in speed and direction of operation are desired.
A further object of the invention is to provide an electric motor wherein a
direct current is employed, thus avoiding the use of switching devices, and
complicated wiring or controlling devices are not required.
A further object of the invention is to provide a motor wherein the armature
and field are independently revoluble, and the desired variation in speed and
direction of operation is secured by varying the strength of current supplied to
the armature or field.
A further object of the invention is to provide a motor having the armature
and held independently revoluble, and one of these parts being rotated by an
auxiliary motor.
A further object of the invention is to provide a hoisting motor for elevators
or other purposes, which is exceedingly simple in construction and manner of
ontrol.
Other objects of the invention will appear more fully hereinafter.
The invention consists substantially in the construction, combination, location
and relative arrangement, all as will be more fully hereinafter set forth, as shown
in the accompanying drawings, and finally pointed out in the appended claims.
Referring to the accompanying drawings, and to the various views and reference
signs appearing thereon,-
Fig. 1, is a view partly in side elevation and partly in diagram illustrating a
construction and arrangement embodying the principles of my invention.
Fig. 2 is a similar view illustrating certain modifications embraced within the
spirit and scope of my invention.
Fig. 3, is a similar view illustrating certain other modifications embraced
within the spirit and scope of my invention.
The same part is designated by the same reference sign wherever it occurs
throughout the several views.
In carrying my invention into practical operation, I employ a motor having
its armature and field independently revoluble, one of such parts being rotated or
driven by an auxiliary motor. By such a construction and arrangement I am
enabled to control the movements of the motor, or the application of the same,
as to speed or direction, by merely varying the strength of the current supplied
to the field or armature, thus dealing with a direct current and avoiding the use
of switches or other controlling devices, or complex wiring.

page_text: Either the armature or the field may be driven by the auxiliary motor, and
the auxiliary motor may be of any suitable form, construction and arrange-
ment, and may be an electric, steam, gas, gasoline or other type of motor.
In the drawings illustrating various arrangements embodying the principles
of the invention, reference sign B designates the auxiliary motor. This auxiliary
motor may be an electric motor, as shown in Figs. 1 & 2, or a steam, gas or other
form of motor, as shown at B', Fig. 3. The driven part of the operating motor,
whether it is the armature or the field, may be actuated from the auxiliary
motor B, B, in any suitable manner. For instance, such driven part may be
carried by or driven from a shaft A, the latter being driven or rotated by the
auxiliary motor. In the form shown in Figs. 1 & 2, the armature C, of the
operating motor is the part that is driven, while in Fig. 3 the field D', is shown
as the driven part of the operating motor. The driven part may be mounted
directly on or otherwise suitably connected to and driven from the shaft A, as
clearly shown. In the case where the armature is the driven part of the motor,
the field D may be assembled in co-operative relation thereto but revoluble
independently thereof, as shown in Figs. 1 & 2, and where the field is the driven
part the armature C, C, may be assembled in co-operative relation thereto but
revoluble independently thereof.
From the foregoing description it will be seen that by employing an operating
motor with an armature and field independently revoluble, one of these parts
being driven by an auxiliary motor, the rotation of the other part, its speed and
direction, may be controlled by merely varying the strength of current supplied
to such armature or field, and hence I can effect a control of the motor, or the
part thereof employed for transmitting motion or power, in a most simple and
efficient manner, having to deal with direct current only, and merely to change
the strength thereof.
This
A convenient and exceedingly simple arrangement is shown wherein a
main switch J is employed, suitably connected to a source of current.
switch, when closed, closes a circuit iudicated by reference sign a, to an insulated
ring K, carried by or suitably connected to the field; thence such circuit leads
through wire b, to and through the field coils D, wire c, ring L, wire d, and
switch J, to the return wire." At the same time another circuit is closed by
switch J, through wire f, ring M, wire g, the armature, to wire c, and return,
to switch J through ring and wire d. Thus by introducing a suitable con
trollable resistance or other current-varying device in either the circuit of the
armature or that of the field, the desired control of the motor as to directio
and speed is effected. Thus, when the curents flowing through the armature
and field, respectively, of the operating motor, are such as to tend to produce a
speed of rotation equal to that at which the driven part is driven by the auxiliary
motor, then there is a tendency of the driven part to hold the other part at
rest; but when the currents flowing through the armature and field, respectively,
are such as to tend to produce a faster speed of rotation than that at which the driven
part is driven, then the driven part exerts its power to drive the other part in
the opposite direction with respect thereto, and at a speed equal to the difference
between the speed at which the operating motor is tending to revolve and that
at which the driven part is driven and if the current flowing through the arma-
ture and field, respectively, is such as to tend to produce a slower speed of
rotation than that at which the driven part is driven, then the driven part exerts
its power to drive the other part in the same direction in which the driven part
is rotating, and at a speed equal to the difference between the speed at which
the driven part is driven and the speed at which the operating motor is tending
to revolve. It is obvious that the means through which the current strength
is varied may be introduced into the circuit of either or both of the parts of
the motor. Thus the main switch J, when once closed requires no further
attention.
It is obvious that only one operating motor may be associated with the auxiliary

page_text: motor as shown in Figs. 2 & 3, or said auxiliary motor may drive the driven
part of two or any number of motors, as indicated in Fig. 1.
In case the auxiliary motor is an electric motor as shown in Fig. 1, the mains
or feeder wires a, b, through which current is supplied to said auxiliary motor,
may also be employed for feeding the operating motors, a switch J, being
employed in connection with each operating motor. Thus the operation of any
one or all of the operating motors may be arrested by suitably manipulating
the switches J, without arresting or interfering with the operation of the auxiliary
motor. A master or wall switch N, may be employed for controlling the mains
or feeders a¹, 61, and of course when the circuit is broken at this switch all the
motors are arrested, including the auxiliary motor.
A motor embodying the principles above explained may be used for any
purpose for which a motor is required, by suitably connecting the machinery
shaft or other thing with the operative element of the motor. In the drawings
I have shown my invention as applied to the hoisting motor of an elevator. In
this case the operating element of the motor may be carried by, formed on, or
otherwise suitably connected to, a drum E, E¹ upon which is wound the hoisting
cable F, said cable, after passing over suitable guide sheaves G. being connected
to the car H. Of course, if desired, any well known, suitable or convenient
arrangement of multiplying gears may be employed, as will be evident to any one
skilled in the art. In the particular form shown in Figs. 1 & 2, to which, how-
ever. the invention is not to be limited or restricted, the armature C, is mounted
on shaft A, and the drum E, which carries or is connected to the field D, is
loosely sleeved on said shaft with the armature C, in concentric relation with
respect thereto, and the cable F, is adapted to be wound on or unwound from
said drum.
As shown in Fig. 3, the hoisting drum E¹, is suitably connected to the arma-
ture C, the field D', being mounted on or driven from shaft A.
The current-varying device, indicated at 0, may comprise suitably arranged
resistance coils, and may be arranged in the circuit a, through the motor field.
A simple and convenient arrangement is shown wherein the wire a, leads from
switch T, to a contact f¹, on the car, thence through a contact bar g¹. and through
the resistance coils O, and wire a. to ring L. The resistance coils O, may be
so relatively arranged with respect to lever g, that when said lever stands in a
vertical position, for instance, the current flowing through the field D, is of such
strength that the speed of rotation at which the operating motor tends to revolve
equals the speed at which the armature is driven, and therefore, as above
explained, the field D. is stationary and the car is at rest. Now. by moving the
lever or bar gl, to the right, the strength of the field current is reduced by having
to traverse more of the resistance coils, and by moving said lever to the left
the strength of the field current is increased by reason of its having to traverse
fewer of the resistance coils. Thus a most simple control is provided, requiring
merely two wires to the car, a resistance box, and an operating lever or bar.
Instead of driving the driven part of the operating motor at a constant speed,
it is obvious that provision may be made for varying the sneed of the auxiliary
motor, or for varying the relative speeds of both motors. Such an arrangement
is shown in Fig. 2. wherein the master or wall switch N¹, is connected by
wire a to post a, at which point the current divides, one part passing through
wire a, the armature of the auxiliary motor, wire a, to post af, and return
wire 7. The other part passes through wire a8, to ring M, where it divides,
one part passing therefrom through wire . armature C. of the operating motor,
wire a10, ring I to return wire a¹¹. The other part of this divided circuit
leads through wire a, to contact devices f³, on the car, whence it may be
completed through lever or arm f, to either contact f. f, according to which
direction said lever is rocked, said contacts being separated from each other but
electrically connected together: thence through wires 13, 14, and a", to the
return. If desired, by centering the control lever, a circuit may also be arranged

page_text: to be broken through the coils of a solenoid R, arranged to operate a brake P,
carried by a lever S, the arrangement being such that when the solenoid is
energized the brake is released, and when the solenoid circuit is broken the
brake is applied.
The
As seen in Figure 2, when the control lever ft, is in centered position the
circuit between plates f, or f, and plate f³, is broken. This breaks the circuit
of solenoid R, and hence causes or permits the brake P, to be applied.
solenoid circuit, which is broken by the centering of lever ft, may be traced as
follows: From switch N1, through wire a², post a³, wire as, wire a12, plate f³;
lever f, plate f³, or f6, wire a¹³, solenoid R, wire a¹, wire a¹¹, to switch N¹. This
circuit is completed when lever ft. is moved either to the right or left from
centered position, and is broken when said lever is in centered position, for in
such position the connection between f³, and the plates f, or f6, is broken. When
this circuit is completed the solenoid is energized and the brake is released.
When this circuit is broken the solenoid is not energized and the brake is applied.
From the foregoing description it will be seen that the armature of auxiliary
motor B, and the armature C, of the operating motor, are in parallel relation with
respect to each other, and that they may be fed with a constant current.
From contact strip f³, on the car, a circuit is completed through lever f4, to
resistance coils W, from opposite ends of which, circuits are completed as follows:
Through wire, post 66, wire 7, the field coils of the auxiliary motor B,
wire 8, post aº, and return wire . The circuit from the opposite end of
resistance coils W, is completed as follows: Through wire, ring K¹, wire,
the field coils D, of the operating motor, wire c, wire 10, ring L', wire a", to
the return. The separated contacts f, f, lever ft, and resistance coils W. are
so relatively arranged that when said lever occupies a central position the current
flowing through the field coils of the auxiliary and operating motors are of such
respective strength that they produce an equal speed of rotation in each motor,
and the circuit through contacts f, and f", is broken. Under these conditions
the operating part of the operating motor, or in the particular case shown, the
drum E, will not be rotated._the_brake_circuit_will_be_broken._and_consequently.
field of the auxiliary motor will be increased and the field D, will be decreased,
thus also disturbing the electrical equilibrium in the opposite direction and
causing the drum E, to revolve in the opposite direction to raise the car. This
movement of the lever f, also closes the brake circuit through contact f³, and
hence releases the brake. The extent to which the lever ft, is moved or thrown
in either direction, determines the extent of variation in current strength, and
the desired variation in direction of rotation and speed of the operating part of
the operating motor is effected through the conjoint action of variations in the
current strength supplied to the operating motor and to the auxiliary motor.
In the foregoing specification I have described how variations in speed and
direction of rotation of the operating part of the operating motor may be obtained
by varying the speed of the operating motor, also by varying the speed of
both motors. It is obvious that the same results may be obtained by merely
varying the speed of the auxiliary motor.
It is obvious that the brake feature may also be applied to the arrangement
shown in Figs. 1 and 3.
From the foregoing description it will be seen that I provide an exceedingly
simple method of control of motors; that direct currents are employed; that

page_text: the operating circuits are never broken except when it is desired to completely
cut out of operation the entire system, or any one or more of the operating
motors, and this cut out is effected through the main switches J, N, or NT,
and hence injurious effects of sparking are avoided; and that the only circuit
which is broken is the brake circuit, and this may carry a comparatively weak
current.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that
what I claim is:-
1. An electric motor having its armature and field independently revoluble,
and means for driving one of the parts, as and for the purpose set forth.
2. An electric motor having its armature and field independently revoluble,
and an auxiliary motor for driving one of these parts, as and for the purpose
set forth.
3. An electric motor having its armature and field independently revoluble,
and means for varying the strength of currents supplied to said parts to vary
the relative speed and direction of rotation of said parts, as anu for the purpose
set forth.
4. An electric motor having its armature and field independently revoluble,
in combination with means for driving one of these parts, and means for vary-
ing the speed at which the other part revolves with reference to the speed of
the driven part, as and for the purpose set forth.
5. An electric motor having its armature and field independently revoluble,
in combination with means for driving one of these parts, and means for vary-
ing the direction of rotation of the other part with reference to the direction
in which the driven part revolves, as and for the purpose set forth.
6. An electric motor having its armature and field independently revoluble,
in combination with means for driving one of these parts, and means for vary-
ing the relative strength of current supplied to said parts for varying the
relative speed and direction of rotation thereof, as and for the purpose set
forth.
7. An electric motor having its armature and field independently revoluble,
an auxiliary motor for driving one of these parts, and means for varying the
relative strength of current supplied to said armature and field, as and for the
purpose set forth.
8. The combination with an auxiliary motor, of an operating motor com-
prising an armature and a field independently revoluble, one of these parts
arranged to be driven by the said auxiliary motor, independent circuits for said
armature and field, and means for varying the current through one of said
circuits, as and for the purpose set forth.
9. An electric motor comprising an armature, means for driving said arma-
ture, and an independently revoluble field, as and for the purpose set forth.
10. An electric motor having its armature and field independently revoluble,
means for driving said armature, circuits for independently supplying current
to said armature and field, and means for varying the strength of the current
in the field circuit, as and for the purpose set forth.
11. An electric motor having its armature and field independently revoluble,
and an auxiliary motor for driving said armature, as and for the purpose set
forth.
12. An electric motor having its armature and field independently revoluble,
and an auxiliary motor for driving said armature, and means for varying the
relative strength of currents supplied to said field and armature, as and for the
purpose set forth.
13. The combination with an auxiliary motor and a shaft driven thereby, of
an operating motor having its armature and field independently revoluble,
cne of these parts being driven from said shaft, as and for the purpose set forth.

page_text: 14. The combination with an auxiliary motor and a shaft driven thereby, of
an operating motor having its armature and field independently revoluble, one
of these parts being driven from said shaft, and means for varying the strength
of the current passing through the other part with reference to that passing
through the driven part, as and for the purpose set forth.
15. The combination with an auxiliary motor and a shaft driven thereby, of
an operating motor having its armature and field independently revoluble, said
armature being driven from said shaft, as and for the purpose set forth.
16. The combination with an auxiliary motor and a shaft driven thereby, of
an operating motor, having its armature connected to said shaft and driven
thereby, and an independently revoluble field. and means for varying the rela-
tive strength of current supplied to said field and armature, as and for the
purpose set forth.
17. The combination with an auxiliary motor, and a shaft driven thereby,
of an armature mounted on said shaft to rotate therewith. and a co-operating
field for said armature, said field being independently journaled upon said
shaft, as and for the purpose set forth.
18. The combination with an auxiliary motor, and a shaft driven thereby.
of one or more apertures mounted on said shaft and driven thereby, a field for
each armature. each field being independently journaled upon said shaft, and
means for varying the strength of current supplied to said armatures and fields,
as and for the purpose set forth.
19. The combination with an auxiliary motor, and a shaft driven thereby,
one or more armatures mounted on said shaft to rotate therewith. an inde-
pendently revoluble field for each armature. an independent circuit for each
armature and field, and means for varying the relative strengths of currents
in said circuits. as and for the purpose set forth.
20. The combination with an auxiliary motor, of an armature and its co-
operating field. these parts being independently revoluble, and one of said parts
being driven from said auxiliary motor. a drum connected to the other end of
caid. marta__...
11.
23. In an electric elevator, an armature, a co-operating field, these parts being
independently revoluble, means for driving said armature, a car, and connections
between said car and field. as and for the purpose set forth.
24. In an electric elevator. an armature a co-operating field, an auxiliary
motor for driving said armature, said field being revoluble independently of
said armature, a car, and connections between said car and field, as and for
the purpose set forth.
25. In an electric elevator, an armature. a co-operating field. an auxiliary
motor for driving said armature, said field being revoluble independently of
said armature, a car, connections between said car and field, and means for vary-
ing the strength of current passing through said field with respect to that pass-
ing through the armature, as and for the purpose set forth.
26. In an electric elevator, an auxiliary motor, a shaft driven thereby, an
armature and a field, these parts being independently revoluble and one of said
parts connected to and driven by said shaft, car, and connections between
said car and the other of said parts, as and for the purpose set forth.
27. In an electric elevator, an auxiliary motor, a shaft driven thereby, an

page_text: armature mounted on to rotate with said shaft, an independently revoluble field,
a car, and connections between said car and field, as and for the purpose set
forth..
28. In an electric elevator, an auxiliary motor, a shaft driven thereby, an
armature mounted on to rotate with said shaft, a field independently sleeved
upon said shaft, a car, and connections between said car and field, as and for
the purpose set forth.
29. In an electric elevator, an auxiliary motor, a shaft driven thereby, an
armature mounted on to rotate with said shaft, a field independently journaled
upon said shaft, a hoisting drum connected to said field, a car, and connections
between said car and drum, as and for the purpose set forth.
30. In an electric elevator, an auxiliary motor, a shaft driven thereby, a drum
independently sleeved upon said shaft, an armature and a field therefor, one of
said parts driven from said shaft and the other connected to said drum, a car, and
connections between said car and drum, as and for the purpose set forth.
31. In an electric elevator, an auxiliary motor, a shaft driven thereby, an
armature mounted on said shaft to rotate therewith, a drum loosely sleeved
upon said shaft, and carrying a field to co-operate with said armature, a car, and
connections between said car and drum, as and for the purpose set forth.
32. In an electric elevator, an auxiliary motor, an armature and field, these
parts being independently revoluble, one of said parts being driven by said
auxiliary motor, a car, connections between said car and the other of said parts,
and means controllable from the car for varying the relative strength of currents
supplied to said armature and field, as and for the purpose set forth.
33. In an electric elevator, an auxiliary motor, an armature driven thereby,
an independently revoluble field, a car, hoisting connections between said car
and field, and means controllable from the car for varying the relative strength
of current to said armature and field, as and for the purpose set forth.
34. In an electric elevator, a motor having its armature and field independently
revoluble, means for driving one of these parts, a hoisting drum connected to
the other of said parts, a car, hoisting connections between said car and drum,
independent circuits for said armature and field, one of said circuits being con-
trollable from the car, as and for the purpose set forth.
35. An electric motor having its armature and field independently revoluble,
means for driving one of said parts, a brake for the other of said parts, circuits
for said armature and field, and means whereby when the driven part is tending
to hold the other part at rest said brake is actuated, as and for the purpose set
forth.
36. An electric motor having its armature and field independently revoluble,
means for driving one of these parts, and a brake for the other, circuits for said
armature and field, and means whereby when the relative strengths of the
currents supplied to said armature and field are varied, said brake is released,
as and for the purpose set forth.
37. In an electric elevator, an auxiliary electric motor, and an operating
motor, the latter comprising an armature and a field, said parts being indepen-
dently revoluble, and one of said parts being driven from said auxiliary motor,
and means for varying the relative strength of currents supplied to said auxiliary
electric motor and said operating motor, as and for the purpose set forth.
38. In an electric elevator, an auxiliary electric motor, and an operating
motor, the latter comprising an armature and a field, these parts being inde-
pendently revoluble, means for supplying a constant current to the armatures
of said motors, and means for reciprocally varying the strength of current supplied
to the fields of said motors, as and for the purpose set forth.
39. An electric motor having its armature and field independently revoluble,
and means for varying the relative speeds of those parts, as and for the purpose
set forth.
40. An electric motor having its armature and field independently revoluble,

page_text: and means for varying the relative direction of rotation of these parts, as and
for the purpose set forth.
41. An electric motor having its armature and field independently revoluble,
and means for varying the relative speed and direction of rotation of these parts,
as and for the purpose set forth.
.42. An electric motor having its armature and field independently revoluble,
in combination with means for driving one of these parts, and means for vary-
ing the relative speed and direction of rotation of these parts, as and for the
purpose set forth.
43. An electric motor having its armature and field independently revoluble,
means for driving said armature, and means for varying the speed and direction
of rotation of the field with respect to said armature, as and for the purpose
set forth.
44. In an electric elevator, an armature, a co-operating field, an auxiliary motor
for driving said armature, said field being revoluble independently of said arma-
ture, a car, connections between said car and field, and means for varying the
speed and direction of rotation of the field with respect to that of the armature,
as and for the purpose set forth.
45. In an electric elevator, an auxiliary motor, an armature and field, these
parts being independently revoluble, one of said parts being driven by said
auxiliary motor, a car, connections between said car and the other of said parts,
and means controllable from the car for varying the direction of rotation of the
one part with reference to that of the driven part, as and for the purpose set
forth.
46. In an electric elevator, an auxiliary motor, an armature driven thereby,
an independently revoluble field, a car, boisting connections between said car
and field, and means controllable from the car for varying the direction of
rotation of said field with reference to that of the armature, as and for the
purpose set forth.
.
47. An electric motor having its armature and field independently revoluble,
means for driving one of these parts, and a brake for the other, circuits for said
armature and field, and means whereby, when the speed at which the driven
part is driven equals that at which the said motor tends to revolve, said brake
is applied, as and for the purpose set forth.
Dated this 12th day of December 1899.
HAROLD ROWNTREE.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.