Improvements in Electrical Elevator Apparatus.
Year: 1891

page_text: Cate of Application, 13th Jan., 1891-Accepted, 14th Feb., 1891
COMPLETE SPECIFICATION.
Improvements in Electrical Elevator Apparatus.
A communication from abroad by OTIS BROTHERS & COMPANY, a Corporation
organized and existing under the laws of the State of New York, of New
York, in the United States of America.
We, AMERICAN ELEVATOR COMPANY of 4 Queen Victoria Street in the City
of London, Elevator Makers, 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 that class of elevators in which electricity is employed
as the motive power for moving the cage; and the invention has for its object to
insure certainty in the operation of the motor, and to prevent injury to the apparatus
liable to result from excessive currents or from arresting or unduly reducing the
speed of the armature from any cause, or from the heating of the parts.
In consequence of the fact that unskilled help is generally employed for operating
the controlling devices of elevator-motors, accidents are liable to occur from
improper manipulation of said devices, and this is especially the case when electro-
motors are employed, inasmuch as any overloading or obstruction to the movement of
the car or platform, and consequent diminution or cessation of the speed of the armature
of the motor, prolonged for any considerable time, will cause the armature or other
parts to be over-heated or burned out, the undue reduction of the speed of the armature,.
as is well known, diminishing the counter-electro motive force so that the current
soon exceeds the capacity of the armature coils to carry the currents without
danger.
If a fusible conductor or safety fuse is employed, the same is apt to be burned.
out in case of the failure of the armature to maintain its proper speed, causing
delay and annoyance, while when resistance coils are employed, if the attendant-
should so adjust the parts that the current passes through but a portion of the
resistance, the coils may become over-heated, and if the parts are not soon properly
adjusted, are injured or burned out.
The present invention consists in means fully set forth hereinafter whereby the
circuit is broken automatically without injury to any part of the apparatus should.
the controlling devices be improperly adjusted, or in case of excessive currents
being sent over the main line, and whereby the armature is cut out of circuit in
case its movement is unduly diminished or if the cage or counterweight exceeds the
limit of its motion, and means are provided for indicating the fact to the operator
should the bearings or resistance become over-heated, or should the controlling
device be improperly adjusted.
On reference to the accompanying drawings:-
-
Fig. 1, is an elevation showing part of the operating electro-motor and part of an
elevator apparatus.
Fig. 2, is a sectional view of a timing device.
Fig. 3, is a view illustrating a modification.
Fig. 4, is a view showing portions of the apparatus with the parts in a different
position from what is shown in Fig. 1.
Fig. 5, is a view illustrating a modification.
The electro-motor A, may be of the usual or suitable constructions, and as shown,
is provided with a field magnet 12, and revolving armature 13, as in the well known
Eickneyer-motor, in which the field magnet has a surrounding casing of iron in the
magnetic circuit, and in connection with the motor is used a current controller,
preferably in the form of a resistance device B, which also may be of any suitable
construction, but is, as shown.rovided with a switch or cut-out 40, so connected

page_text: with the conductors and arranged in respect to the resistance terminals 41, 42, and
connected with the properly wound armature, that the movement of the switch
from its mid-position, shown in. dotted lines Fig. 1, to one side, will close the circuit
through the resistance and will gradually cut out the resistance and impart motion
to the armature in one direction, while the movement to the other side will gradually
cut out the resistance and impart movement to the armature in the other
direction.
Combined with the electro-motor and the resistance device is a shifter device
constructed and connected to be operated in any suitable manner from the cage or
platform so as to throw the switch to any desired position, and in connection with
these parts are employed means whereby the shifter is automatically restored to its
normal position, carrying the switch to its mid-position and throwing upon the
circuit of the motor whenever the operator fails to properly adjust the switch, or in
case the motor moves at an improper speed, or should an excessive current be thrown
on the main line.
Different means inay be employed for bringing the shifter and the parts con-
nected therewith to the mid-position, and the shifter may be of different constructions
varying with the character of the apparatus.
In the construction shown in Fig. 1, the shifter is in the form of a bar 3, sliding
horizontally in bearings on the base C, and the winding drum D, is geared with the
armature shaft through the medium of the worm 47, on said shaft, and worm-
wheel 48, upon the shaft 7, of the drum D.
The ordinary shifting rope may be employed to move the shifter 3, but it is
preferred to use the double travelling rope device shown in Fig. 1. This consists
of two ropes or cables X, X', passing over elevated guide pulleys 50, and around
guide pulleys 51, 51, carried by a lever 52, connected with the shifter, the opposite ends
of each rope being connected to a lever 53, upon the car at opposite sides of its
shaft 54, which passes through the car and is there provided with an operating
handle 55. These parts are so arranged that the handle 55, will be in its mid-position
when the shifter is in its mid-position, so that the operator in the car can thereby
know at all times the actual position of the shifting device.
A toothed sector 20, pivoted to the frame of the machine, is connected with the
shifter 3, and gears with a pinion 5, upon the shaft 4, that carries the resistance
switch or cut-out 40, so that when the shifter 3, is moved by the manipulation of
the handle 55, or other device, the switch 40, will also be moved to an extent pro-
portioned to the movement of the handle.
Any suitable means may be employed for carrying the shifter, when not other-
wise controlled, to its mid-position, shown in Fig. 1. Thus springs 11, are confined
between shoulders 43, upon the shifter, and bearings 44, upon the frame, so that one
of said springs will be compressed when the shifter is moved in either direction
from its central position.
As a result of this construction, should the attendant move the shifter so as to
carry the cut-out 40, to such a position as to cut only a part of the resistance on
either side, that spring 11, which is compressed, will immediately upon the release
of the handle move the shifter to its central position, cut out the entire current and
arrest the machine.
In order that the shifter and the switch 40, may be maintained in position when
the resistance has been properly cut out to either side, and to avoid the
necessity, when the engine is running properly, of the operator maintaining
continuous hold upon the handle 55, a detent, is combined with the shifter a
governor operating the former to hold the shifter in place so long as the motor
moves at the proper speed, but to release it when the speed decreases.
'Such detent may be constructed in various ways and the governor may be a
governor of any of the usual forms connected with the armature shaft or other part
of the machine, in any way so as to be driven thereby.
'Thus the detent 16, is in the form of an L shaped pawl, one arm of which has a
projection 10, that enters a V shaped notch 18, in the shifter whenever the latter is

page_text: at the limit of its movement in either direction, while the other arm of the detent
enters the groove of a sleeve 15, of a ball governor G, upon a prolongation of the
armature shaft.
The above described parts are so adjusted and proportioned that when the
armnature is revolving at the proper rate of speed, the shifter will be held by the
detent, but should the cage be overloaded, or the armature for any other reason be
obstructed in its movements so als no longer to be operating under proper
conditions, or the counter-electro-motive force falls below a condition of safety,
then the change in the position of the governor will shift the pawl and release the
shifter which will at once assume its mid-position, shifting the switch 40, and
arresting the motion of the machine. As the notches and the projection 10, have
bevelled or inclined faces, the operator can at any time shift the switch by
exerting sufficient force to move the shifter and lift the projection 10, out of the
notch.
In the construction shown in Fig. 1, the weight of the car is counterbalanced by
a weight L, connected with the cable wound on the drum in a direction the reverse
of the cage cable, as usual. The parts are arranged so that neither the cage nor
the counterweight will on proper operation of the apparatus touch the floor, but
should either be brought against the Hoor thereby arresting the revolution of the
armature and governor, the projection 10, of the detent will be withdrawn and the
switch will assume automatically its position to break the circuit.
To prevent injury from the transmission of excessive currents to the motor, a
solenoid 28, electro-magnet, or other electro-motor connected with the detent 16, is
placed in the main-circuit and proportioned so as to be operated only by a current in
excess of the normal current, to thereby lift the detent and release the shifter,
which assumes at once its mid-position, thereby preventing the armature from
being driven at an excessive speed, or from over-heating.
To indicate to the attendant upon the platform any improper action of the
apparatus resulting in heating either the bearings, the resistance, or other part or
parts, a thermostat 17, is placed in connection with each of such parts,
and in a circuit including a switch connected to be operated by said
thermostat, is placed an alarm bell 30, or other suitable signal, upon the cage, so
that the movement of the switch completing the circuit at once results in
signalling to the operator. Any of the usual forms of thermostats or cut-outs may
be used in this connection.
In order to further indicate to the attendant the fact that he has only
partially moved the switch to its position, as the parts would burn out if the
switch was left partly turned, there is combined with the switch and with
the alarm bell or indicator and circuit including the latter, a switch or circuit
breaker I, so arranged as to break the circuit when the switch is in its normal
position, or in the proper position at the limit of either movement, but so as to
complete the circuit and sound the alarm when the shifter is at any other point of
its movement. Thus in the circuit a, including the bell or other indicator 30, are
two seperable plates 56, 56, mounted upon, but insulated from the shifter or
otherwise controlled by the change of position of the switch, and supported above
the plate is a flexible contact piece or brush 9, which is in the circuit and extends
between the plates or is otherwise out of contact with them when the shifter is in
its mid-position, and which is opposite and out of contact with the outer end of one
of the plates 56, when the shifter is in either extreme position, but otherwise when
the shifter is at intermediate points, is in contact with one of the plates and
completes the circuit, causing the indicator to be operated to indicate to the
operator the fact that the switch or shifter has not been moved to a proper extent.
It will be evident that this arrangement may be reversed, so that the indicator is
operated when the shifter is in a central position only, as shown in Fig. 5, the
circuit being broken when the shifter moves to either side.
Although in Fig. 1, there is shown the shifter 3, in the form of a bar and.
controlled by springs to carry it to a mid-position, it may be in the form of a disk.'

page_text: Thus the shifter disk 3, Fig. 3, may be mounted upon the end of the shaft 4, of
the resistance device, and a cord W, passing between guide pulleys 47, is attached
to the edge of the disk and carries a weight that normally brings the disk to the
mid-position shown, at the same time turning the shaft 4, and the switch 40,
attached thereto. In this case the detent 16, bears upon the edge of the disk, and
if desired the hand shifting rope X, may extend around the disk in a groove
thereof.
The switch or circuit breaker of the thermostat may control a circuit (dotted
lines b. b. Fig. 1) through the solenoid or its equivalent 28, so as to lift the detent
and shift the main switch 40, upon the heating of the parts, and any suitable form
of current controller may be substituted for the resistance device B.
In order to further insure against the switch being left for an excessive time in
any position where the current would be on, without turning the armature at the
proper speed, a time arrangement is employed which is set to release the shifter bar
after a given limited time, such that no overheating of the resistance and other
parts can take place. This is practicable in elevators, as the length of a trip
scarcely ever exceeds a few moments. Any of the well known timing arrange-
ments; clocks, fans or pendulums may be used. In the drawings is shown a dash
pot or cataract of the usual construction, consisting of a cylinder 71, piston 72,
piston rod 73, and circulating channel 70. The motion of the shifter bar either
way from the centre lifts the piston, until the bolt 74, is pushed back by the
inclined cam 75, by the pin 80, on the bolt travelling on the inclined face of the
cam. The piston returns now to its bottom position and the toe 76, in its down
path strikes the detent bolt 77, and releases the shifter bar 3, which then returns to
the centre and opens the circuit shutting off the current.
In consequence of the incline of the notches in the bar the operator can by the
application of sufficient force shift the bar at any time when the bolts are in the
notches which is the normal condition; the said bolts or detents coming into
operation after a limited time and in certain contingencies described. Thus assum-
ing that the operator has shifted the bar to the position shown in Fig. 4. and that
all the detents are in the notches, which is the normal condition immediately after
shifting the bar, if under these circumstances the detent 16, were withdrawn, the
timing bolt 77, would still prevent an immediate return of the bar and the cutting
off of the current by the switch 40. In any event the bolt 77, holds the bar so that
the operator can let go the lever in the car without the necessity of bearing upon it
until the motor gets its proper speed. The timing arrangement is set to unlock
after the proper speed is required, in which case the detent 16, holds the bar. If
then the movement of the armature should stop or be unduly reduced, or if the
current through the magnet 28, should become too strong, the detent 16, would be
released.
It will be seen from the above that the bolt 77, of the timing device, is intended
to hold in case the detent fails or form any circumstances is drawn out of operation,
but it releases the bar before damage can result from an excessive current, or in
case the detent is in in-operative condition to release the bar so that it will be under
the control of the detent.
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 the electro-motor of an elevator, of a current controlling
device, constructed to both reverse and vary the current, and provided with a switch,
means for automatically turning the switch to its normal position with the current
cut off, and means for operating said switch from the cage to carry it from its
normal position in either direction, substantially as set forth.
2. The combination in an elevating apparatus cf an electro-motor, controller
provided with a switch, a shifter connected with said controller and with the cage
to be operated therefrom, automatic means for carrying the shifter to one position, a

page_text: detent for holding the shifter in another position and a governor connected with
said detent and driven from a moving part of the apparatus, substantially as set
forth.
3. The combination with the cage and electro-motor of an elevator, of a controller
provided with a switch, a shifter connected to be operated from the cage and also
connected to said switch, means for carrying the controller to one position, a detent
engaging with bearings upon the controller to hold it in another position in either
direction, a governor driven from the armature and connected with said detent, the
parts being arranged to release the shifter when the speed of the armature is
reduced, substantially as set forth.
4. The combination with the shifter connected to be operated from the cage, and
with the switch, of an alarm upon the cage, and a circuit breaker carried by the
shifter to complete the circuit including the alarm when the position of the shifter
is changed from one position to the other, substantially as set forth.
5. The combination of the switch controlling the current to the motor of an
elevator, of a circuit indicator, and a circuit breaker connected to move with said
switch and in circuit with said indicator, substantially as described.
6. The combination with the cage and electro-motor, of a resistance controlling
the current to the motor, the switch or cut-out of said resistance, a shifter connected
to be operated from the cage and with said switch, automatic means for carrying
the shifter to its mid-position, and a detent and governor controlling the same for
holding the shifter in its extreme positions, substantially as set forth.
7. The combination with the motor and cage of an elevator, of a regulating
switch controlling the circuit to the motor through a series of resistances, a detent
controlling the switch, and an electrical governor for the detent arranged in the
main circuit and connected with the detent to release the switch when the main
current becomes excessive to allow the switch to return to its normal position,
substantially as set forth.
8. The combination with an electro-motor, a switch controlling the current
through the same and means for moving the switch to one position, a detent for
holding it at the limit of its movement in either direction, of a timing device for
releasing the detent, substantially as set forth.
9. The combination with the switch and with the shifting devices connected with
the elevator cage, of a detent for holding the switch constructed to yield under the
action of the shifting device, substantially as described.
10. The combination with an elevator cage and electro-motor connected to operate
the cage, of a switch controlling the circuits to operate the motor in either direction,
devices for carrying the switch to its normal position, a detent for locking the
switch in its operating position, and automatic means for operating the detent,
substantially as set forth.
11. The combination with the cage and shifter bar and connections for moving it
from the cage, of a switch and a lever connected with said bar and having a rack
engaging a pinion on the switch shaft, substantially as set forth.
12. The combination with the cage, motor, switch and yielding detent for
holding the switch in one position, and a spring for shifting the switch, substantially
as set forth.
Dated the 12th day of Lana 1001
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Agent for the Applicants.