Improvements in Starting and Stopping Devices for Electrically Operated Elevators.
Year: 1896

page_text: Date of Application, 19th May, 1896-Accepted, 11th July, 1896
COMPLETE SPECIFICATION.
Improvements in Starting and Stopping Devices for Electrically
Operated Elevators.
A. communication from abroad by OTIS BROTHERS AND COMPANY, of 38 Park
Row, New York, in the United States of America, Manufacturers.
We, OTIS ELEVATOR COMPANY LIMITED of 4 Queen Victoria Street, in the
City of London, 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 automatic stop devices for use in connection
with electric elevators, and it has for its object to provide means whereby the
elevator or the motor operating the elevator may be stopped or controlled
automatically when through any cause the operator fails to properly manipulate
the controlling devices, and to these ends it consists in the various features of con-
struction and arrangement of parts, having the mode of operation, substantially as
hereinafter more particularly set forth.
While the invention is more particularly applicable to use in connection with
electric elevators, the general principles of the invention may be applied and
adapted for use in other connections without departing from the spirit of the
invention, although it is designed more especially, and is shown herein, in connection
with an electric elevator.
In the accompanying drawings.
Fig. 1, is a side view showing one general arrangement of electric elevator
devices, sufficient to illustrate the present invention.
Fig. 2, is a plan view thereof.
Fig. 3, is a diagrammatical representation of the circuits and apparatus connected
therewith, and
Fig. 4, is a sectional view of the mechanical automatic stop device.
It is well known that in the operation of ordinary hydraulic or other elevators
which are controlled by the operator on the car, it is common to provide some
means which will automatically stop the movement of the car, as for instance, at
the extremes of its up or down motion, if for instance, the operator fails to
properly manipulate the controlling devices, so that accidents can be prevented
from the car moving too far, and the present invention has for its object to provide
means whereby the same results may be accomplished in connection with electrically
operated elevators.
The invention is shown as embodied in an apparatus arranged so that when the
automatic stop is brought into operation, it will control a circuit of the elevator
motor in such a manner that it will cause the armature of the motor to send 'a
current through the circuit which will tend to stop the armature, and consequently,
the elevator connected to be operated from the armature of the elevator motor.
This circuit is controlled in the present instance by a make-and-break switch which
is operated by the automatic stop device, and this operation may be accomplished
in various ways, some of which will be specifically set forth hereinafter, and the
parts are so arranged that the ordinary operations of starting and stopping the
elevator motor do not interfere with the operation of the automatic device, and

page_text: rice versa the automatic device does not interfere with the operations of the ordinary
starting and stopping apparatus.
With this general statement of the invention, it will now be described in
connection with the embodiment shown in the accompanying drawing, wherein A,
represents an electric motor of any ordinary construction, and the shaft A', is
connected to the armature of the motor and is provided with a worm A, engaging
a worn-wheel A, connected to a winding drum A', which operates in the usual
Connected with the motor A, is some suitable circuit-controlling device
for stopping, starting and reversing the motor, which is indicated at B, the details
of which are not shown, as they may be varied and are well known, and this
controlling mechanism is operated from the car through the medium of a hand-
rope B, or equivalent device connected in the present instance to a lever B',
operating the sbaft B, of the controller. The apparatus is shown as being
provided with a suitable mechanical brake device C, which may be of any well
known construction, and which in the present instance is operated by a shipper
bar D, and this shipper bar is shown as mounted to reciprocate in the bearings dd,
being moved by a lever B, connected with the hand-rope and controlling device.
So far, the apparatus is shown as a typical construction to which the invention is
applied, and of course, it can be varied without affecting the present invention.
Arranged in connection with the apparatus above described is a switch E, and it
is shown in the present instance as mounted on the controlling apparatus, although
it may be otherwise arranged in any convenient manner, and this switch is con-
trolled by an electro-magnet E', and is preferably in the form of a double break
switch (see Fig. 3,) having two arms E, E, of conducting material, although it
may be provided with a single arm and operate as a single break switch. It is
shown in the present instance as having spring terminals e, e, e, e, and in dotted
lines are shown the terminals e, e, which co-operate with the arm E, also shown
in dotted lines.
The present construction also embodies a make-and-break-switch F, operating in
connection with the terminals, ff, and this make-and-break-switch or brush F, is
controlled by a cam F. This cam, is operated by a dise G, having in the present
instance a pin or projection g, arranged to engage the cam F, when the disc is
operated in the manner hereinafter set forth, and this disc is loose upon its support
and is provided with some means for causing it to maintain its normal position, as
the weight W, or equivalent device, which also tends to restore it to its normal
position when moved, as hereinafter set forth. This disc G, is in the present
instance connected with and forms part of an automatic mechanical stop, best
shown in Fig. 4, which is of the well-known construction and consists essentially of
a drum G', loosely mounted on the shaft A', of the winding drum, so as to rotate
thereon, which shaft is provided with a screw-thread G, on which are adjusted at
proper positions the clutch members G, G', which rotate on the shaft. Mounted
to move on the screw-threaded portion of the shaft is a bar G, which is also
provided with two clutch members on opposite sides and which normally traverse
in slots G, G', in the drum G, without, rotating said drum, But when the bar
reaches either extreme of the screw-threaded portion so that one or the other of
its clutch members engages with one or the other of the clutch members G³, G,
the bar and consequently the drum G', will rotate with the shaft, and this carries
the disc G with it, causing it to rotate to bring the pin g, into a position to
operate the cam F', and the brush F, connected thereto, to make or break the
circuit.
The dise G, is also provided with another pin or projection g, which is arranged
to engage a similar pin or projection or equivalent device h, on the pinion H, which
pinion engages a rack on the shipper bar D, and is moved with said bar to the
right or left as said bar is moved by the operator to start and stop the motor.
These pins 9, and h, are so arranged that in the ordinary movements of the
shipper bar D, in starting and stopping the motor, they do not impinge upon each
other, so that the disc G, is not moved in the, ordinary operations of the elevator

page_text: mechanism, but when under the conditions hereinafter set forth these pins do come
together, the automatic stop device controls the circuit of the motor to prevent
accidents, as will appear later.
In the preferred construction of the invention there is also provided a circuit-
breaker I, shown in the present instance in the form of a disc having alternate
conducting and non-conducting surfaces, as I, I, against which bear the
terminals,, of the circuits, and this disc is operated so as to partially rotate in
accordance with the movements of the shipper bar D, and in the present instance
it is attached to a pinion 1, which engages a rack on the shipper bar D, so as to
move therewith. The brake device C, is also shown as being mechanically
controlled by the shipper bar D, the arm C', of which engages a notch in the
shipper bar, so that when the bar is in the normal condition the brake is applied,
but when it is moved to the right or left in starting the motor, the brake is
mechanically lifted and is restored into operative position by a weight, spring, or
other equivalent device when the shipper bar is moved to stop the motor.
Such being the general construction and arrangement of the mechanical parts,
the circuits will be best understood by reference to Fig. 3, wherein the motor A, is
conventionally shown, in which a, a', are the armature brushes, b, b', are the
terminals of a reversing switch K, and S, represents the shunt field-magnet coils,
while S', represents the series field-magnet coils. R, is a resistance in the armature
circuit which may be automatically controlled in the well-known way, and R', is an
auxiliary resistance in the control circuit of the motor, and P, M, represent,
respectively, the plus and minus terminals connected with the feeding circuit of
the motor.
While the motor itself may be variously wound and connected, it is herein
shown as a compound wound motor, and the circuits thereof may be traced as
starting from the positive binding-post P, through the conductor 1, through the
shunt field-magnet coils S, and to the minus pole M, while a shunt or branch
conductor 1, leads to the binding-post b, of the circuit-reverser K, and thence to
one of the brushes a, through the armature, to the other brush, and back through
the terminal 4, in one or the other direction according to the position of the
circuit-reverser, and by the conductor 2, through the series field-magnet coils S',
through the resistance R, to the minus binding post M, as is usual in this class of
motors. Connected to the conductor 1, which is connected by the branch 1* to the
terminal & of the circuit reverser K, is a conductor 3, leading through the auxiliary
resistance R', to the spring contact e, on the switch E, and connected to the spring
contact e', on the switch is a conductor 4, which leads to the conductor 2, at a
point between the armature coils and the series field-magnet coils, so that the
current may pass through the series field-magnet coils, and by a conductor 5, to
the contact piece 2, on the switch, and the contact piece e, is connected to a
conductor 6, to the 'binding post b', of the circuit-reversing switch, so that when
the switch E, is closed, there are two closed circuits, one including the armature
through, 1, 3, R', e, E, e¹, 4, 2, b', a', a, b, 1, and the other the series field-magnet
coils of the motor through 5, e2, E3, e3, 6, 2, S', and the motor will send a current
through the armature circuit which will tend to stop the motor, it being practically
short-circuited on itself. In some instances it is preferred to leave the series field-
magnet coils out of the short-circuit controlled by said switch, and this can readily
be accomplished by connecting the brushes a, a', in a circuit including the
conductor 7, connected to the contact pieces e, e, controlled by the connector E,
of the switch, and in this way the armature alone of the motor is short-circuited,
there being preferably a resistance R', included in this circuit, which may be
adjusted to meet the requirements of any particular case.
The electro-magnet E is operated in the present instance by a circuit controlled
by the automatically operated disc G, and the circuit-breaker 1, and this circuit is
shown as connected to the main circuit in any way, as to the conductor 1, and
passing thence through the conductor 8, which includes the coils of the electro-
magnet E', to a point 9, where it branches, one portion or branch passing by the

page_text: conductor 10, through the switch F, and thence to the minus binding-post, while
the other branch passes by conductor 11, through the terminals i, i, controlled by
the circuit-breaker I, to the conductor 10, and thence to the minus binding-post,
and it will thus be seen that there are in fact two circuits or two branches of the
same circuit controlling the electro-magnet El, and as long as either une of these
branch circuits is closed, the magnet E', will be energized, so as to hold the switch E
open but when both of these branch circuits are broken, the switch E, will be closed
to short-circuit the motor in the manner before indicated.
From this description it will be apparent to those skilled in the art how the parts
operate to perform the functions intended, and it will be seen that in the ordinary
condition, as represented in the diagram, the motor is represented as stationary, and
the circuit-breaker in a position to break the circuit of the magnet El, while the
automatic switch F, is in a position to close the circuit of the magnet E, and the
switch E, is shown as being open.
As is usual with this class of mechanism, the operator in the car, by means of
the haud-rope B', or similar device, closes the ciremt through the motor and through
the armature in one or other direction, as the case may be, in order to cause the
elevator to move up or down, and the shipper bar D is moved in a corresponding
direction by an arm B connected with the ordinary controlling devices, and this
shipper bar operates to rotate the circuit-breaker I, to close the circuit through
the contacts i, i, by its connection with the pinion 1, engaging the shipper bar, and
the pinion H, is also rotated but not sufficient to cause its pin h, to engage the
ping, on the disc G, and the motor may be started and stopped as usual without
affecting the automatic stopping device, as it will be seen that one of the branch
circuits through the magnet E, is closed even though the circuit-breaker I, makes
and breaks the branch controlled thereby, as it does when the shipper bar is moved
the ordinary distance for starting and stopping the motor.
It will be understood that as the elevator traverses up and down, the bar G
moves back and forth on the shaft A', without its clutch portions engaging either
of the clutch purtions G, G, but if for instance, through neglect or otherwise the
motor should not be stopped when the cage reaches the end of its upward or
downward motion, the bar G', would engage one of the clutches G, or G, as the
case might be, and rotate drum G', and this would rotate the disc G, so as to cause
its pin g, to engage the cam F', and break the circuit of the magnet E', at the
switch F, and further the pin g of the disc would engage the pin on the
pinion H, and rotate the same, which would in turn move the shipper bar to its
normal position, breaking the branch circuit through the terminals i, i', and
the circuit-breaker 1, thus de-energizing the magnet E, allowing the switch E, to
operate and close the short-circuit of the armature or armature and series field, as
the case may be, thereby tending to stop the motor.
It will be understood by those familiar with the operation of the stop motion
gear, that this will produce a comparatively slow motion of the shipper-bar D,
sud not an instantaneous or rapid throw of the bar, and consequently, of the
circuit-controlling device B. If this circuit-controlling device is arranged to
break the circuit of the shunt field-magnet coils when it is in its "off" position, it
is evident that this circuit of the shunt field-magnet coil will not be broken until
the shipper-bar has reached its normal or central position, while it will further be
seen that as soon as the shipper-bar commences to move to its normal position
under the influence of the stop motion gear, the circuit of the magnet E', is broken,
and the switch E, is closed, and the armature and series field-maguet coils of the
motor are short-circuited. This causes the armature to operate as a brake under
the influence of the shunt feld-magnet circuit until the shipper-bar practically
reaches its normal position, when if the controlling device B is so arranged, the
shunt field-magnet coils will be cut out. Even then, the magnetism of the motor
disappears slowly so that for practical purposes it will be found immaterial whether
the shunt field-magnet circuit is broken or not at the controlling device. In
practice it may be arranged so that after the stop motion gear commences to

page_text: operate, the car may travel, say ten feet, while the pinions H and I are moving to
their normal or central position. It will be seen that almost as soon as the parts
engage, or within the first two feet of the movement of the car, the circuit of the
magnet El, is broken, and the switch E closed, thereby short-circuiting the armature.
and series field-magnet coils of the motor, and these remain short-circuited while
the shunt field magnet coils are still closed at the controlling device under all
conditions.
As the car reaches the last portion of the ten feet of travel assumed above,
the shipper-bar is carried to its normal or central position, so that the controlling
device B is in its normal or open position, and as before stated, if this is arranged
(as it often is) to open the shunt field circuit, it will be opened at this time, when
the car has practically stopped, but there will still remain the magnetism of the
motor to operate on the armature, and further it will be seen that when
the shipper-bar reaches this position, the brake C, is automatically applied to
stop the car, if it has not already stopped. It will be understood, of course,
that if the shunt field-maguet circuit is not broken at the controlling device B, as
it is arranged in some instances, there is always a strong field for the armature to
operate in as a brake.
To avoid a too sudden reduction of the speed of the armature under these
conditions, it is preferable to provide the auxiliary resistance R', or R', to limit
the current which can be produced in the armature of the motor, and cause it to
stop gradually. Under these conditions, the stop motion or disc G, will continue
to carry the pin g, a certain distance beyond the position necessary to operate the
cam F, before the car comes to rest, and if now the car is started in the
opposite direction by the operator moving the shipper bar in the reverse direction,
the pinion H, is turned, separating the pins h, and g and the automatic stop will
gradually release the disc G, and the weight W, will bring it back to its normal
position, which will close the switch F, in this movement. This motion, however,
is somewhat slow, depending on the inertia of the car with which the automatic stop
works in unison, and the car must, therefore, travel a certain distance before the
ping, will arrive at a position to close the switch F, by moving the cam F', and
thus closing the circuit through the electro-magnet E', to operate the switch E, and
as long as the electro-magnet is not attracted, the switch E, remains closed and the
elevator motor can only rotate slowly, while using a great amount of power.
This undesirable feature in an automatic stop, however, is overcome by means of
the circuit-breaker 1, arranged in a branch circuit of the magnet E', which branch
circuit is closed by the operator whenever the shipper bar D, is moved sufficiently
far from its normal position to cause the terminals i, i, to bear on the conducting
portions of the disc or circuit-breaker I, and the electro-magnet El, is, therefore,
rendered operative as soon as the shipper bar has been moved the proper distance
in starting the car in the right direction, even from its extreme position at top or
bottom, after its travel has been arrested by the automatic stop devices, as before
set forth.
From this general description and illustration of the invention, the principles
thereof will be readily understood by those skilled in the art, and it will be seen
that it may be adapted for many and various purposes and used with various
devices, and further it will be seen that the automatic stop mechanism may be used
alone without the circuit-breaker, although it is preferable to use the two together
to control the circuit of the switch magnet, which in turn controls the short-circuit
of the motor armature or armature and series field-magnet coils.
In Fig. 3, a conventional circuit-reverser is indicated in order to better explain
the circuits, and the circuit-reverser (of whatever form) used would naturally be
placed on or in the circuit-controlling device B, although of course, it might be
placed anywhere else so far as this invention is concerned. A plug or cut-out, is
indicated on circuit line 1, and it is such as is ordinarily employed in working
circuits derived from main distributing circuits, and this of course, can be of any
form and may include one or both of the connectors with the mains or not.

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, as communicated to us by
our foreign correspondents, we declare that what we claim is,―
1. The combination with an electric motor and a short-circuit therefor, of a
switch controlling said circuit, and an automatic stop device controlling said switch,
substantially as described.
2. The combination with a motor and a short-circuit therefor, of a switch con-
trolling said short-circuit, and a magnet controlling said switch, the circuit of which
magnet is controlled by an automatic stop device, substantially as described.
3. The combination with a motor and a short-circuit therefor, of a switch con-
trolling said circuit, a magnet controlling the switch, an automatic stop device
controlling the magnet, and a circuit-breaker also controlling the magnet,
substantially as described.
4. The combination with a motor and a short-circuit therefor, of an electro-
magnetic switch controlling the circuit, an automatic stop device controlling the
switch arranged in one branch of the circuit thereof, and a circuit-breaker also
controlling the switch arranged in another branch of the circuit thereof, substantially
as described.
5. The combination with a motor and a short-circuit therefor, of an electro-
magnetic switch, an automatic stop device controlling said switch, and a shipper
bar connected with said automatic stop device and arranged so that the shipper bar
may operate under normal conditions without operating the automatic stop device,
substantially as described.
6. The combination with a motor and a short-circuit therefor, of an electro-
magnetic switch, an automatic stop device controlling the switch, a circuit-breaker
also controlling the switch, and a shipper bar connected with both the circuit-
breaker and automatic stop device, substantially as described.
7. In an electric elevator, the combination with the motor and starting and
stopping device therefor, of a short-circuit connected with the motor, a switch
controlling the short-circuit, a circuit-breaker controlling the switch, and a shipper-
bar connected with the control mechanism of the motor for controlling the circuit-
breaker, substantially as described.
8. In an electric elevator, the combination with the motor and starting and
stopping device therefor, of a short-circuit connected with the motor, a switch
controlling the short-circuit, an automatic stop device controlling the switch, and
a shipper bar connecting the automatic stop device and starting and stopping
device of the motor, substantially as described.
9. In an electric elevator, the combination with the motor and starting and
stopping device therefor, of a short-circuit for the motor, an electro-magnetic
switch controlling the short-circuit, an automatic stop device controlling the switch,
a circuit breaker also controlling the switch, and a shipper bar connected with
both these devices and with the starting and stopping mechanism, substantially as
.described.
10. In an electric elevator, the combination with the motor and starting and
stopping device therefor, of a short-circuit for the motor, a switch controlling the
motor, an automatic stop device controlling the switch, and connections between the
automatic stop device and the ordinary starting and stopping devices, substantially
as described.
11. In an electric elevator, the combination with the motor and starting and
stopping device therefor, of a short circuit controlling the motor, an electro-magnetic
switch controlling the circuit, an automatic stop device controlling said switch
arranged in one branch of said electro-magnetic switch, a circuit-breaker arranged
in another branch of said electro-magnetic switch, and a shipper bar connected with
the ordinary starting and stopping devices, substantially as described.
12. In an electric elevator, the combination with the motor and the circuit
controlling the same, of an automatic stop device comprising a switch controlling

page_text: the circuit, a disc controlling the switch, a pinion, a shipper bar, and connections
between the disc and pinion, substantially as described.
13. In an electric elevator, the combination with the motor and the circuit
controlling the same, of an automatic stop device comprising a switch controlling
the circuit, a cam connected to the switch, a disc having a pin engaging the cam,
a pinion, a shipper bar connected to the pinion, and connections between the pinion.
and disc whereby the shipper bar is operated, substantially as described.
Dated this 5th day of May 1896.
PHILIP M. JUSTICE,
55 & 56 Chancery Lane, London, Chartered Patent Agent,
For the Applicants.