Improvements in and connected with Elevator Apparatus.
Year: 1891

page_text: Date of Application, 2nd Sept., 1891-Accepted, 5th Dec., 1891
COMPLETE SPECIFICATION.
Improvements in and connected with Elevator Apparatus.
A communication from abroad by OTIS BROTHERS & Co., of 38, Park Row, New
York, in the United States of America, Manufacturers.
We,
AMERICAN ELEVATOR COMPANY of 4, Queen Victoria Street in the City
of London, Manufacturers 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 :-
The object of the first part of this invention is to provide means whereby an
electro-motor connected with an elevator apparatus will be automatically cut out
of circuit or otherwise rendered inoperative in case an excessive contra-electro-
motive force is induced in it, such means being illustrated in Figs. 1, and 2, of the
accompanying drawing.
In said Figures A, is the cage, B the suspension rope passing to the usual
drum C, D the electro-motor the shaft D¹ of which is geared to drive the drum,
S a switch arranged to pass from a central position in which the current is cut out
over contacts, shown in dotted lines Fig. 2, which gradually cut out the resistance
so as to start the motor in either direction and vary the speed or stop it as required.
The switch is moved by means of a pinion S', on the switch shaft s, and sector
lever E connected with a sliding bar F, which is shifted from the cage by means
of a hand rope H, passing around a pulley H, a pinion G₁ and a sector lever G
engaging said pinion and connected with the bar F. I, is a brake device of suitable
character bearing upon some suitable part of a motor when the parts are in the
position shown in Fig. 1, but when the bar F is shifted to start the motor in either
direction the inclined side of a notch f, of a bar will lift the brake device 1.
Springs K, K¹, tend to hold the bar F, in its normal or middle position with the
motor circuit broken.
These devices may be varied as required and are shown only to illustrate the
improvements hereinafter set forth.
Fig. 2 illustrates the circuits the terminals of the motor connected at P, N, to
the line L. Also connected to the terminals P, N, is a line M, of high resistance
formed into one of the coils of a solenoid O, the resistance of this circuit being so
regulated that under normal conditions a light current will pass through the circuit.
Also connected to terminals P, N, is a third circuit Q, including another set of
coils of the solenoid O, also a lever R and contact R' which lever R is connected
to the core of the solenoid to carry the same, the circuit being normally broken
between R and R¹. Also in the circuit Q, is a magnet or solenoid T, the core
pivotally connected with the detent T₁, and having a bevelled end adapted to
notches t, t, in the bar F.
In the position shown no current passes through the motor which is stationary.
When the bar F is shifted in either direction to start the motor the detent Ĭ"¹
engages one of the notches t or t¹, and thereby locks the bar in position as long
as the motor runs normally with the proper amount of current. When any cause
induces contra-electro-motive force in the motor more current will be forced
through the shunt circuit M of high resistance energizing the magnet O, lifting its
core and closing the circuit Q, of comparatively low resistance at the point R, R.
This circuit Q, receives a large proportion of the current so that the solenoid T, is
energized to lift the detent TT and unlock the bar F which will be restored to its
normal position by the spring K or K¹ whereby the switch S is brought to a mid-
position to cut out the motor when the current will flow normally through the
line and a spring will draw down the core O¹ and restore the circuits to proper
position.

page_text: The second part of the invention relates to a motor for use in constant current
circuits and to provide means whereby the strength of the magnetic field may
remain practically unchanged and the necessary starting power or torque may be
produced to the best advantage to start the motor under load and yet run the same
without danger of exceeding the margin of regulation of the generator or the
heating limit when such a motor is used on a constant potential circuit.
This portion of the invention is illustrated in Figures 3 to 8.
In Figs. 3 and 4, A represents the commutator of a generator, a', a², a³, com-
mutator plates, and Fig. 5 shows diagrammatically one well known form of
connecting the terminals to the commutator plates. B is the brush holder mounted
on the shaft C and carrying brushes D. D¹.
66
Means are provided by which some of the windings or coils can be shunted_or
short circuited or otherwise rendered inactive. Thus, there may be employed a
coupler" E mounted on a coupler head F, sliding on a shaft C. The coupler
arms are in the form of U-shaped springs fixed to the coupler head but insulated
therefrom and so arranged that when the head is thrown towards the commutator
plates each coupler arm will make contact with two adjacent bars or plates a, a², etc.
and connect the same electrically so that they then form practically a single bar
thereby shunting the winding of the armature between said pairs of bars and
reducing the number of effective windings on the armature.
In Fig. 6 the commutator is shown displayed, assuming the coils to be wound as
illustrated in Fig. 5. Starting at the commutator bars A, the conductor 1, (Fig. 5.)
passes over the surface of the armature core through the conductor 2, returning
at 3, passes by the wire 4 to the plate a', by the wire 5 around the core back by
the wire 6 and 7 to the plate a², by the wire 8, 9, 10, to the plate a³ and thence by
the wires 11, 12, 13 to the plate a', and so on as usual. The brushes are supposed
to be placed on the plates a and a', under normal conditions and at starting the
current passes through each of these coils in series from one brush to the other and
the whole number of windings is rendered effective to overcome the friction at
starting and the inertia of the parts, and the force exerted (the current and strength
of the field magnets being normal) is proportional to the number of effective
windings included in the circuit. When the requisite speed and power is acquired
and the proper amount of contra-electric motive force exerted, some of the coils
are short circuited or otherwise rendered ineffective by bringing the coupler into
action, as will be readily understood when the motor will rotate at its normal speed
and produce the required power.
Any desired means may be employed for shifting the coupler, as a ball governor G,
Fig. 7, with a crank lever H, engaging the sleeve of the governor and an annular
recess, in the coupler head. In the construction shown in Fig. 8, the crank
lever I has at its outer end a weight Y, connected with the piston of a dash pot K
and a projection 15, on the shifter bar 16 rides under a stud 17 to lift the weighted
end of a lever or let it descend as the shifter bar 16 is moved to communicate
motion to the switch 20, through the rack lever 18 and pinion 19. When the shifter
bar is moved in either direction to start the motor the maximum power will be
applied and the coupler head F will only be shifted as the piston of the dash pot
descends to the limit of its lower motion.
While one means has been described other means may be used to shunt or
otherwise render ineffective part of the windings of the armature manually,
automatically, or otherwise.
The third part of the invention relates to means whereby the operator in the
cage of an elevator may be notified of any change in the operation of the engine
and in means for preventing a series electro-motor from using an unnecessary
amount of electro-motive force, this part of the invention being illustrated in
Figs. 9 to 13.
În said figures, A is the motor, 1. the armature on a shaft 2, N, S, the poles of
the field magnets the multiple coils of which connect with one section of the main
line and lead to terminals 3, 3, 4, 4, 5, arranged between contact. plates 7, 8, in

page_text: connection with the other section of the main line. The reversing switch consists
of two arms 9, 10, pivoted at the lower ends swinging over the terminals and
connected by an insulated bar 12. The arm 9 is electrically connected with one
of the armature brushes and the arm 10, with the other brush and the terminals of
the field magnet coils are properly looped together for instance as in Fig. 12 to
secure a correct action in diminishing the electro-motive force of the motor and in
reversing the current and direction of rotation of the armature. In the position
shown in full lines Fig. 12, the line is open, no current can pass to the motor and
the latter is at rest. When the parts are shifted to the position shown in dotted
lines Fig. 12 the arm 10 is on the terminal 5 and the arm 9 on the terminal 7, to
complete the circuit in such manner as to secure the maximum strength of the field
and the highest electro-motive force of which the machine is capable. Throwing
the switch to the right to bring the arm 9 on to the terminal 5, secures the same
result with a reversal of the rotation of the armature. If the power developed is
too great the switch is shifted to an intermediate position.
The switch may be shifted from the cage through the medium of a shifter bar
and toothed sector levers and pinions as shown in Fig. 10, and before described,
and the operator in the cage therefore can regulate the effective power of the
motor to vary the voltage to the work required avoiding waste of power while
maintaining efficiency in the engine.
An indicator I, avoids constant attention to the running of the engine and a
governor C, controls the force operating the indicator. The indicator may be a
visual signal, as an electric lamp shown in Figs. 9 and 11, or a pointer operated by
a weight and piston moved by variations in a fluid column as in Fig. 13. The
governor may be constructed in any suitable manner to vary the current or column
or other signal actuating means. In Fig. 11, the governor shifts a circuit closer c,
between terminals a, b, so that when the speed of the engine becomes excessive it
completes the circuit including the light in the car and thus warns the operator.
The indicator is also moved in the construction shown in Fig. 13 when the descent
of the lever 28, forces the fluid column upward.
To prevent accidents from negligence the governor applies a brake J, when the
speed becomes excessive so as to bring the shoe 21, against a wheel 22 to create a
resistance to the motion of the engine.
To arrest the momentum of the engine to suddenly stop the machine a weighted
lever K carries a shoe 24, which bears upon the wheel 22, when the lever descends
which it does when the shifter bar 16, is brought to a central position with the
notch therein below a friction pulley 25 carried by the lever K.
The fourth object of the invention is to reduce the danger of injury to operators
and others should leaks occur to ground from some portion of the circuit, to which
end the construction illustrated in Figs. 14, 15, is employed.
In said construction the motor receives the current from a conductor 16 which
passes around the field magnet cores 18, 19, to a contact plate 12, adjacent
contacts 1 and 2 being each connected to an out-going conductor 17. The switch S
has arms 6, 7, pivoted and connected together the latter connected to a conductor 20,
passing to the brush 10, while the arm 6, is connected by a conductor 22, to the
brush 9. In the position shown in Fig. 15 no current passes to the motor, but
moving the switch to either side closes the circuit. Between the contacts of the
switch are other contacts 13, 14, smaller than the ordinary contacts connected
together and to a conductor 23, leading to ground and having in line a high
resistance coil 5 to prevent too rapid discharge to the ground, and in this circuit is
also a signal device as a lamp 4. Thus, each time the switch is moved there is a
possible connection with the ground and if this exists it is at once indicated by the
signal which serves as a warning but the connection is but momentary. Thus, for
instance supposing there was a leak to ground from the conductor 16, entering the
motor and the motor switch should be operated for instance by moving it to the
right, so that the lever 6, would bear npon the contact 2, and the lever 7, upon

page_text: the contact 12, and the motor would be set in operation thereby. As the switch
arm 7 is moved it would momentarily bridge the contacts 13 and 12 and the signal
in the high resistance line would be operated, the current from the leak might be
traced from the line 16 through the field magnets to the contact 12, thence by the
arm 7 to the contact 13, thence through the resistance 5, the signal 4, wire 23 to
ground, and through ground back to the leak in line 16, and the same effects will
occur although the circuit would be slightly different, if there should be a leak on
the conductor 17.
The fifth part of the invention is for means whereby after the application by the
operator of the power required to start the engine the said power is subsequently
automatically varied.
This feature of the invention is illustrated in Figs. 16 to 20.
In said figures A is the hoisting drum driven from a suitable engine through the
medium of a worm wheel 3 and worm 2 on a shaft 4 connected to be rotated by
the engine.
X is the cage, 5 the hand rope, 6 the lower hand rope pulley on a sleeve 18 in
line with the shaft 1 of the drum and carrying a pinion 7, gearing with a rack 8,
connected in any suitable manner with the valve spindle or other stopping and
starting device of the engine. Connected with the pinion 7, is a clutch section in
the form of a pawl 9, Figs. 16, 17, 18, pivoted to a carrier shown in the form of a
disc 10, secured to the pinion 7 the pawl being pressed inward by a spring 12 towards
the edge of a notched disc 13, connected to turn with the drum or portion of the
engine. Normally the pawl engages one of the notches of the disc 13, so that
the revolution of the shaft 1, would carry the pawl and turn the pinion 7 and
connect the parts, but there is adjacent to the disc 13, a fixed cam plate 14, with
which a finger i, on the pawl makes contact, the pawl being thereby lifted out of
the notch when moving in either direction towards the cam plate.
The operator turns the pinion 7, to shift the valve which is open to its full
extent to bring the maximum energy of the motor fluid into action to start the
engine.
Normally the point of the pawl occupies a mid-position at y, on the cam and the
shifting of the starting device in either direction carries the pawl beyond the end of
the cam plate into one of the notches in the disc 13, and the motor starts under the
full energy of the fluid. As soon as the engine begins to move after its inertia is
overcome the disc 13 carries the pawl on to the cam plate 14, until the pawl is
lifted from the notch in the disc when the latter and the engine will continue their
movements. The movement imparted by the pawl to the disc 13, however, acts
through the parts connected with the disc to turn back or close the valve to a
limited extent so as to reduce the maximum force of the motor fluid to the extent
required for normal continuous operation. The length of the cam 14, may be varied
or the notches separated to a greater extent or set closer together to vary the
amount of return movement automatically imparted to the valve.
In the construction shown in Fig. 20 the two parts 16, 17, of the clutch can
connect the shafts 1 and 18 together. On the lower hand rope pulley 6 is a cam 22,
engaging a bell crank lever 24, with studs entering a groove 25, of the clutch
section 17, which slides on the shaft 1, and turns therewith being thrown in one
direction by a spring 26. A lateral pin 9ª projects from the section 17 over the
edge of a stationary curved cam 14. Fig. 20 shows the parts at rest, but when
the hand rope is pulled the pulley 6 turned and the valve is shifted to its full
extent, the cam 22 moves away from the lever 24 so that the spring 26 throws
together the clutch section. The engine then begins to move and the valve is
turned backward gradually throttling the motor fluid until it is throttled to the
required extent when the pin 9" will ride up one of the inclines of the cam 14ª,
thereby disengaging the section 17 from the section 16 and arresting the further
closing of the valve after which the engine will continue its normal operation.
Different appliances may be used for automatically throwing back the valve or

page_text: other controlling device after it is set to its full extent to secure a maximum power
to start the engine, and those described are merely for the purpose of illustrating
some of the forms in which this feature may be embodied.
The cam 14 may be composed of two adjustable pieces as shown in Fig. 19.
The sixth feature of this invention relates to that class of apparatus illustrated
in connection with some of the engines previously described in which a worm-wheel
is driven by means of a revolving worm.
As it is well known worm gears are attended with objections incident to imperfect
fitting, unequal wear and undue friction, abraison and heating.
To overcome these objections the construction illustrated in Figs. 21 to 27 is
adopted.
In said Figures, A, is the worm on the shaft 1, and B the worm wheel on the
shaft 2. The worm-wheel B consists of two or more sections 4, 4, each circular
and arranged alongside the other and the teeth are cut across the edges of the
different sections. The hub may be in one piece with one of the sections, or
sectional, or, as shown, the hub 5, may be independent of all the sections confined
loosely thereto between flanges 6, 7. One or all the sections have yielding bearings
on the shaft. The two sections illustrated have each a projection 8, extending into
a recess x, in the hub between elastic blocks 9, 10. Thus, each section has its
proper bearing on the worm independent of the others and the wear cannot
be disproportionately upon any one part as each can yield to adapt itself to
the worm.
The yielding bearings need not be elastic for as shown in Figs. 24, 25, each
section may bear on one end of an equalizing lever 12, having its fulcrum on
the body.
Having now particularly described and ascertained the nature of the said
invention, as communicated to us by our foreign correspondents, and in what manner
the same is to be performed, we declare that what we claim is :-
.
1. The combination with the cage of an elevator and an electro-motor for
operating the same, of a switch controlling the circuits through the electric motor,
a shunt of high resistance around the switch, and another shunt of lower resistance
controlled by the high resistance shunt, the said low resistance shunt controlling the
operation of the motor, substantially as described.
2. The combination with the cage of an elevator, and an electro-motor for
operating the cage, of a switch controlling the circuits of the motor, connections
with the cage for operating the switch, a high resistance shunt around the motor, a
normally open shunt of lower resistance also around the motor and the said low
resistance shunt including a device engaging the switch operating mechanism of the
motor, substantially as described.
3. The combination with the cage of an elevator, and an electro-motor and
connections for operating the elevator, of a switch controlling the circuits of said
motor, a bar connected to be operated with the cage and controlling said switch a
detent engaging said bar, and shunt of high resistance around the motor, and a
normally open shunt and solenoid included therein for operating the detent, substan-
tially as described.
4. The combination with the cage of an elevator and electro motor, and
connections for operating the same, of a switch controlling the circuits of the
motor, a bar controlled by the operator for moving the switch, a detent for engaging
said bar, a circuit of high resistance around the motor the coils of the switch
magnet included in the said circuit, a normally open circuit of lower resistance also
including the coils of the switch magnet, and a coil included in said circuit for
operating the detent, substantially as described.
5. The combination with a circuit over which a constant current is sent, of an
electro motor included in the circuit and connected to operate an elevator, a shunt
of high resistance around the motor and a normally open shunt of lower resistance
including a detent magnet controlling the motor, substantially as described.

page_text: 6. The method of starting and operating electric motors which consists in passing
the current through all the coils of the armature to render them effective on starting,
and subsequently shunting a portion of the coils to render the current passing
through them ineffective when the motor is under normal speed, substantially as
described.
7. The combination with the armature of a motor, of a shunting device for
rendering some of the coils of the armature ineffective, substantially as described.
8. The combination with the armature of a motor and its commutator, of a
coupling device arranged to couple some of the commutator bars, and shunt the
current through the coupler, substantially as described.
9. The combination with the armature shaft and commutator thereon, of a coupler
head sliding on said shaft carrying couplers arranged to engage and disengage
said commutator bars, substantially as described.
10. The combination with the armature shaft of a motor and commutator thereon,
of a coupler engaging the commutator, a switch controlling the circuit of the motor,
and connections between the switch and coupler, whereby the coupler will be
operated automatically by the operation of the switch, substantially as described.
11. The combination with the armature shaft of a motor and commutator thereon,
of a coupler, a switch controlling the circuits of the motor, means for operating the
switch, and a retarding device for delaying the movements of the coupler, substan-
tially as described.
12. The combination with the travelling cage or platform of an elevator, and
with a stationary engine receiving a current, of a switch movable between the
terminals of the main conductor and field coils, and appliances connected with the
cage and with the switch whereby the operator in the cage can shift the switch,
substantially as set forth.
13. The combination with the cage and series electromotor, the conductor and
terminals arranged upon opposite sides of a central terminal, of a switch provided
with two arms connected to move together upon opposite sides of the central
terminal, and appliances between the switch and the cage for operating the switch
from the cage, substantially as set forth.
14. The combination with an elevator and electro-motor for operating the same,
of a governor or speed device operated by the motor and an indicator in the cage
controlled by the governor to indicate to the operator any undue change in the
speed of the engine, substantially as set forth.
15. The combination with the cage, operating engine and controlling devices
therefor and means for operating the same from within the cage, of a speed device
or governor driven from the engine and an indicator within the cage and means
for operating the same from the governor, substantially as and for the purpose
set forth.
16. The combination with the cage of an elevator and with the motor therefor,
of a speed device driven from the motor, and a friction brake connected with the
governor to apply a frictional resistance to the motion of the parts when the speed
of the motor becomes excessive, substantially as set forth.
17. The combination in an elevator of a series motor, receiving a current of
constant ampheres and variable voltage a switch device whereby to regulate the
extent of the field coils and to break and reverse the circuits, and an automatic
speed device for preventing the excessive speed of the motor, substantially as
set forth.
18. The combination with the engine and shifter bar of a brake, and inclines on
the shifter bar arranged to lift the brake when the bar is moved from its mid-
position in either direction, substantially as described.
19. The combination with the electric motor in a main circuit conductor, and
stopping, starting and reversing switch, of an elevator, of a grounded circuit
including electric signal and means for connecting said signal circuit with the main
circuit on the shifting of the switch, substantially as set forth.
20. The combination with a motor and a starting and stopping switch, of a high

page_text: resistance line to ground, including a signal device and contacts connected to said
high resistance line and arranged within the limits of movements of the switch,
substantially as described, so that the circuit will be completed through the high
resistance ground line momentarily in the operation of the switch, substantially as
described.
21. The combination with an electric motor and current reversing switch
therefor, of a supplementary contact arranged between the circuit contacts of the
switch, the said supplementary contacts being connected to a high resistance ground
line, including a signal device arranged in the path of the arms of the switch,
substantially as described.
22. The combination in an engine with the controlling device thereof, and with
the hand appliances for shifting said device, of connections between the engine and
said device arranged to move the latter from its extreme positions on the movement
of the engine, substantially as and for the purpose set forth.
23. The combination with the controlling device of an engine, of stationary and
movable contact pieces between said device and the engine, and connections whereby
the moveable piece is shifted automatically to arrest the movement of the valve
imparted from the engine, substantially as set forth.
24. The combination of an engine, controlling device, contact piece connected
with said device, contact piece carried with the engine, and intermediate device
for disengaging the contact pieces after the controlling device has been partly
shifted from its extreme position, substantially as set forth.
25. The combination of an engine and notched disc connected to turn therewith,
a controlling device and pawl carrier connected to move therewith, a pawl carried
by the carrier and a cam arranged to lift the pawl when moving from an extreme
position in either direction, substantially as set forth.
26. The combination with a worm and its shaft of a worm wheel composed of
circular sections lying side by side with teeth cut angularly across the faces of the
sections and yielding bearings between one or more of the sections and the shaft
upon which the wheel is mounted substantially as described.
27. The combination with a worm and its shaft of a worm wheel composed of a
hub and circular sections independently mounted upon said hub and yielding
bearings between the hub and the sections, substantially as set forth.
28. A worm wheel consisting of a central hub and peripheral ring sections, the
hub having a recess receiving projections upon the peripheral sections and a
yielding bearing between said projections and the face of the hub, substantially as
set forth.
29. The combination in a worm wheel of a hub and sections mounted independently
upon the hub, and an equalizing lever having a bearing on the hub and on each
section, substantially as set forth.
Dated the 2nd day of Santambor 1201
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Agent for the Applicants.