Improvements in Electric Motors.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in Electric Motors.
I, BENJAMIN WILLCOX of 47 Lincoln's Inn Fields in the County of Middlesex
Patent Agent do hereby declare the nature of this invention (which has been
communicated to me from abroad by Ernest Richard Esmond of 106 Broadway,
New York City in the State of New York, United States of America Engineer
and Contractor) 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 in which both the field and the
armature are rotatable and are combined with an intermediate pinion or the like
by which they are geared together.
This invention consists in making this intermediate pinion or the like (which I
will refer to as the intermediary) capable of bodily swinging movement, to which
end it is mounted on a carrier which is pivoted to allow the necessary swinging
movement of the intermediary. The carrier is preferably controlled by a spring
or its equivalent so that a yielding resistance is offered to the movement of the
intermediary from its normal position.
A motor of this kind has a wide range of use. When employed as a car motor,
the pendulous intermediary can be made to act as a brake, and when used for
elevating or hoisting purposes it will act as a governor to preserve uniform rate of
speed under varying loads, and also to prevent abrupt starting and stopping of the
hoisting apparatus.
In the use of the motor for elevating or hoisting purposes it is preferred to use
the field of the motor itself as the hoisting drum, that is to say the hoisting drum
is mounted on, and carried by, the field of the motor. This feature so far as I am
aware is new whether the intermediary which gears together the field and the
armature be mounted on a fixed, or on a movable carrier.
In the accompanying drawings I have shewn the foregoing features of these
improvements embodied in one apparatus intended to be used for elevating or
hoisting purposes.
Figure 1 is a side elevation and Figure 2 is a longitudinal vertical central section
of the apparatus.
Figure 3 is an elevation of the end at which the intermediary is situated.
Figure 4 is a sectional elevation of the brake mechanism.
Figure 5 is a side elevation of the switch and
Figure 6 is a diagram of the circuits.
A is the rotating field of the electric motor which constitutes also the hoisting
drum. B is the rotating armature; on its shaft is hung an arm D in which is
journalled the intermediary C which engages both with the pinion on the
In the
armature shaft, with internal spur gearing a at one end of the field A.
present instance the intermediary is a compound one of its larger parts gearing
with the armature shaft, and its smaller part engaging with the field as shewn more
clearly in Figure 1 where a part of the field is broken away.
The arm Ď can vibrate on the armature shaft as an axis. In some instances it
will be sufficient to weight its lower end as indicated in dotted lines at D' in
Figure 3 to prevent it from being carried around by the intermediary, and to

page_text: The hoisting rope passes down and under the pulley p thence across under the
machine to the wheel p¹ passing under this wheel thence up over it and down under,
and three or four times around the hoisting drum and thence out under the
pulley p².
The pulleys p p² are mounted on a connected shaft p³ carried by crank arms p
attached to a rock shaft r which carries the moveable member of the main cut-out
or switch r
When the hoisting rope is in order it will, by passing under the pulleys p p²
hold them up in a position in which the switch will be closed.
Should the rope break, or become unduly slack, the pulleys will at once drop
by gravity and in so doing will rock the shaft r in a direction to open the switch
the effect of which as hereinafter described will be to at once apply the brake to
the motor.
On the armature shaft is the commutator E and on the field are the four
annular contact strips F' F2 F3 F insulated from each other. Two or three
strips are electrically connected to the commutator brushes and two of them to the
field. There is an insulated contact brush for each strip F1 F2 F3 F' but these
brushes as well as the commutator brushes are not shewn as their construction is
well known to electricians.
The brake consists of two brake shoes G encircling a hub on the armature
shaft and jointed together at g. One of the brake shoes is pivotted to the frame
of the machine at g' and hh are two toggle arms to which is jointed at their
meeting point a vertical rod i fast at its base to a plate carried by the cores of
the brake solenoids or suction magnets k. Whenever the current is on, the brake
solenoids draw up their cores and thus raise the rod i consequently the toggle
arms are operated to release the brake.
When the current is off, the rod i by its weight and that of the parts attached
to it will drop thus at once setting the brake. Its downward movement can be
assisted by the weighted lever pinned to it as shewn in Figure 4.
The switch for stopping starting and reversing comprises two sets of contacts
each consisting of three pairs d d d². The moveable contact which operates in
connection with them as shewn at e. It is mounted on a rock shaft provided
with a pulley for receiving the operating cord which extends to, and is connected
with it in the same way as is the operating cord in ordinary elevators. When the
parte is engaged with one set of contacts the drum will move in one direction,
when it is engaged with the other set the drum will revolve in the opposite
direction and when in its intermediate position the drum will be at rest.
A resistance box m is provided which is included in the armature circuit and a
resistance solenoid is provided for operating the contact arm n this solenoid
being in the field circuit. The resistance contact arm is connected to the core of
the solenoid. When the solenoid is inactive the core drops and the arm n is
moved in a direction to throw in all the resistance. As soon as the solenoid is
active, it draws up its core, and consequently the contact arm n is moved to
gradually cut out all resistance, and to allow the full measure of current to pass to
the armature.
The contacts d, d' are in the armature circuit and the contacts d² in the field
circuit.
--
The circuit connections are represented in Figure 6 and are as follows:-
The armature circuit, is from the main line, through the resistance box, through
the contacts d and the contact strip F¹, to and through the armature, thence out
through the strip F and contacts & through the brake solenoid and thence back
to linc.
The field circuit is from the main line through the resistance solenoid the
contacts and strip F³ to and through the field, thence out through the strip F¹
to and through the brake solenoid and back to line.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In or for electric elevators or hoisting apparatus, an electric motor com-
prising a field and armature both of them rotatable, an intermediary geared both
to the armature and to the field, and a hoisting drum mounted on or formed with
the field, substantially as herein before set forth.
2. In or for electric elevators or hoisting apparatus, an electric motor comprising
a field and an armature, both of them rotatable, an intermediary geared both to
the armature and to the field, a carrier for the said intermediary vibratory upon
an axis coincident with that of the armature, and a hoisting drum mounted on, or
formed with, the field, substantially as herein before set forth.
3. An electric motor comprising a field and armature both of them rotatable,
in combination with intermediate gearing connecting the two, and a carrier for the
said gearing hung upon an axis on which it can vibrate to permit swinging move-
ment of the gearing carried by it, substantially as, and for the purposes, hereinbefore
set forth.
4. In electric motors the intermediary and its pendulous, spring, or weight
controlled, carrier, in combination with the rotatable field and rotatable armature
of the motor, substantially as, and for the purposes, hereinbefore set forth.
5. The combination, in an electric motor having a rotatable field and rotatable
armature, with the internal spur wheel a and the pinion of an intermediary C
engaging with the said wheel and pinion, and a carrier for the said intermediary
pivoted to move upon an axis coincident with that of the wheel and pinion between
which the intermediary is placed as hereinbefore set forth.
Dated this 2nd day of September 1893.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, Agents.