Improvements in and relating to Electric Elevators or Lifts.
Year: 1891

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by RUDOLF EICKEMEYER, of Yonkers, Westchester,
New York, United States of America.]
Improvements in and relating to Electric Elevators or Lifts.
1, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, 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 :-
In most cases elevators have heretofore been operated, either by steam engines
or by hydraulic motors which are wholly controllable by an attendant on the elevator
car or platform, by means of an accessible hand line.
An extended use of such apparatus has created a demand for a high rate of
speed of the car, and for prompt starting in either direction, and equally prompt
stopping, and these operations practically depend upon the use of cables and
coiling drums.
As an important feature conducive to safety, the said coiling
drums have been so geared or coupled to the motive power mechanism, as to
require the latter to be reversely driven, for hoisting and lowering the car.
Various electric elevator systems have been heretofore devised, but I know of
none which would favorably compare with such otherwise operated elevators as do
fulfil the above enumerated and well recognized requirements.
The prime object of my invention is an electric elevator system which includes
cables and reversely driven coiling drums, and is operated by an electric motor
which can with safety to all its parts, be as promptly started, stopped, and
reversed, by working a hand line accessible within the elevator car, as with any
elevator directly operated either by a hydraulic or a steam motor.
My invention consists in certain novel features of construction, and in novel
combinations of mechanical and electrical devices, all of which are hereinafter
described. Although the best results will accrue from the cooperative use of all
portions of my invention, some of them may be separately employed in elevator
systems more or less varied in their mechanical construction and arrangement.
In the accompanying drawings
Fig. 1 is a side elevation of the hoisting mechanism, the attachment of the car
being in diagram;
Fig. 2 is a corresponding plan view of the hoisting mechanism ;
Fig. 3 is a side elevation of the electric motor and drum operating devices,
partly in section to show the gearing;
Fig. 4 is a plan view of the same, a part of the winding drum and bed-plate being
cut away;
Fig. 5 is a sectional elevation of the brake attachment of the machine;
Fig. 6 is a front elevation of the safety attachment of the machine on an enlarged
scale and detached from the machine.
Fig. 7 is a front view of the switching and reversing devices, detached, on an
enlarged scale;
Fig. 8 is a transverse vertical, and
Fig. 9 a horizontal section of the same;
Fig. 10 is a diagram showing the relations of the circuits and connections ;
Fig. 11 is a front elevation of a modification showing means for producing a
sudden and wide separation of the terminals of the circuit;
Fig. 12 is a side elevation, partly sectional, of the same;
Fig. 13 is a sectional elevation of the same taken from an opposite point of
view; and
T
14
1

page_text: The winding drum and its driving mechanism are mounted on a bed plate A
which is supported upon a suitable foundation. B is the winding drum upon which
the rope C (by means of which the car D is operated) is wound and unwound to
raise or lower the car. The drum B is secured and supported on a shaft & which is
mounted on, suitable bearings on the bed plate A. To revolve the drum, a worm
gear E is secured upon the shaft b in which a worm F meshes, and this worm F, is
coupled directly to the shaft of the motor M.
The motor I employ is what is known as a shunt-wound motor, which is within
certain limits self regulating, and I arrange the various elements so that the
following cycle of operations takes place.
When at rest no current passes, both field and armature being cut out. To start
the motor in either direction, current is first admitted to the field winding to
excite the field. Then current is gradually put in the armature circuit until the
whole current in the circuit is put on the machine. The resistance in the
armature when standing still is so low however that its coils would burn out
should the motor for some reason or other not be able to start-for example, if the
elevator be overloaded or stuck in some way. To guard against this I have devised
self-acting safety device by means of which a certain amount of external
resistance is included in the armature circuit so long as the current which the
armature would otherwise receive is beyond the limit it could safely carry. As
the motor starts and the counter-electro-motive force in the armature increases
this external resistance is automatically reduced or removed. To stop the motor
the resistance which, meantime, has been automatically removed from the armature
circuit is first put in again mechanically, and then the current is gradually taken
out of the armature circuit and at last out of the field circuit.
8.
In the diagram Fig. 10 I have illustrated the switching, reversing, and safety
devices, showing the various connections in the generator and motor circuits, the
dotted lines representing the electric connections. The electric generator G is
connected on the one hand by the line I with the curved plates 2 and 3 on the
switch board, and on the other hand by the line 4 with the plates 5, 6, 7 and 8;
one terminal of the field circuit of the motor M is connected to the plates 2 and 3
(which are always directly connected with one terminal of the generator) and the
other terminal of the field circuit of the motor M is connected with plates 11 and 12
directly.
.
In the centre of the curved bars of the switch board is a shaft upon which
three superimposed brushes are mounted but insulated from each other (see Figs. 7,
8 and 9). In the position shown in Figs. 7 and 10 the brushes rest upon insulating
material, preferably slate or glass. The shaft is by a gear and lever so controlled by
the hand lever or hand rope that the arm carrying these brushes can be turned to
the right or left in manner more particularly described later on. The plates 7 and 8
are in circuit with one terminal of the generator through plate 5, and the plates 11
and 12 with one terminal of the field coil of the motor, whose other terminal is in
circuit with the remaining terminal of the generator.
..
The shorter of the brushes m is of such dimensions that it will connect electrically
the plates 8 and 12 of the inner ring of contact-plates when the brushes are turned
from the perpendicular in one direction, and the plates 7. and .1.1 when turned in the
opposite direction. In either case the current from the generator flows through the
field coil of the motor in the same direction and excites the field...
The electric current should be gradually supplied to the armature, and hence it
is necessary to appropriately reduce the current, and I have provided for this
purpose a rheostat, or series of resistance coils which are cut out or put in by the
operator, and I have so arranged the switch blocks and brushes. that the same
resistance coils are used whether the current from the generator flows in one
direction, or the opposite through the armature of the motor.
"
The terminals of the resistance coils indicated at 2, Fig. 10, are connected to the
insulated switch-blocks as at n, and each one of these blocks is connected by a wire as
shown in dotted lines to a block placed in a corresponding position as at n¹. The

page_text: brushes m¹ and m¹¹ are of such length that m¹ will electrically connect opposite
pairs of curved plates in the middle ring, and the brush m¹¹ will connect opposite
pairs of the curved plates in the outer ring.
I have stated before the manner in which the terminals of the generator are
connected to the switch plates and I will now explain the action of the brushes m¹
and when the latter are turned to one side or the other. Suppose we turn
them in a right-handed direction until we reach the line -y, Fig. 7.
As soon as the brushes have turned far enough to come in contact with the
curved switch-blocks, a circuit is made through the armature of the motor M. The
current will pass as indicated in Figure 10 from the line I to plate 2 through the
brush to first block at n; through the resistance coils r, thence over to the
plate n, through the coil 13 of the automatic regulator, through the resistance
coils of said regulator to one brush o of the motor; through the armature of the
motor to the other brush o', and thence through plates 9 and 10 and brush m¹ to
plate 6 which is electrically connected to plate 5 whence by line 4 the circuit of the
generator is completed.
As we continue the motion of the switch brushes one resistance coil after another
is cut out, until, when the brushes reach the line -y all of the resistance coils are
If the
cut out and only the resistance coils remain in the armature circuit.
brushes be returned to their original position, the resistance coils rare gradually
put into the circuit again, and when the brushes reach the insulating block the
circuit is broken.
If the brushes are now turned towards the left hand so as to come in contact
with the switch-blocks at n¹, the circuit is made again but the current will now
pass through the armature in opposite direction to that previously taken. Entering
from line its path will be from plate 3 through the brush m² to plate 9 to the
brush o' through the armature to brush o, through the resistance and regulator
coils and 13 to plate n", through brush m to plate 5, and thus to the other
terminal of the generator.
It is evident that when a suitable current is supplied that the motor will revolve
in one or the opposite direction when the switch-board brushes are turned in one or
opposite position from the perpendicular line.
The automatic safety device is shown detached from the machine in Fig. 6. It
consists substantially of a suction coil 13 into which a curved iron core (shown in
Fig. 6 by dotted lines) is loosely fitted, one end of the core being attached to an
arm of a bell-crank-lever 14, which is pivotally mounted on a rock shaft having its
bearings in a suitable frame, as ats (see Fig. 9). On a suitable projection of the
lever 14 I have mounted a brush 15 which is in contact with one of a number of
switch-blocks 16 which are the terminals of resistance coils r¹.
The short arm 17 of the bell crank 14 has a small roller which is fitted into a
cam 18 fixed on the rock shaft l.
In Figs. 1, 2, 3, and 4 I have shown an arrangement in which a bar 19 is moved
longitudinally by the hand rope as illustrated in Figs. 1 and 2 or by a hand lever,
as shown in Figs. 3 and 4. This bar is provided with stops at 91 and g" which
limit its motion and at 20 is so shaped that it forms the cam which operates the
brake. As shown in the figures, the bar is in its central position, and by a pull at
the operating-rope, or by means of the hand lever, it can be moved longitudinally
to the right or left until it is stopped by the pins g' org". This movement to the
right or left lifts the weighted brake-block 21 from the brake wheel 22 on the shaft
of the motor M and the armature is now free to revolve.
I have made use of this bar as one of the elements which serve to operate my
switching mechanism; but only because I have taken for illustration a form of
elevator mechanism in which such a bar and brake is commonly used; but obviously
the switching devices could be operated with equal facility directly by the hand
lever, by the operating-rope, or otherwise.
To cause the shaft to revolve when the bar 19 is moved I have mounted on the
frame of the motor a pivoted lever 23 which is slotted to receive a pin in the bar 19

page_text: and is provided with a toothed segment 24 at its upper end which meshes with
another segment 25 on the shaft l.
The lever 23, segments 24, 25, and motion are so proportioned that, when the
bar 19 is moved from one stop to the other, that is, when it is caused to make the
longest possible longitudinal motion, it will cause the shaft to make about two-
fifths of a revolution and thus impart a motion to the switch brushes which will
bring them from the line ' y' so to the line ", y" or vice versa.
If we now assume that the switch-board brushes and bar 19 are in the position
shown in the drawings we find that the brake is set or in its operative position, the
brushes in vertical position with both circuits of the motor open, and that the bell-
crank-lever 14 is held by the cam 18 in such a position that the iron core is
completely enclosed in the suction coil 13. If we now start the bar 19 in one
direction until it is stopped by one of the pins, the brushes will move over the
switch-board until they are in the position a', y', or all, ". The cam 18 which is
fixed on the shaft moves correspondingly and it is so shaped that it will hold the
lever 14 until the brushes on the switch-board have cut out all the resistance at r.
As shown in the drawings the cam 18 has a circular path in the middle and is
widened out on both ends, and while the roller on the arm 17 occupies said curved
slot the magnet core is held in the solenoid, but as soon as the roller on the arm 17
is out of this circular path, the lever 14 is free to move and the iron core is then
capable of swinging outwardly from the coils and the brush 15 can move over the
semi-cylindrical faced switch-block and cut out the resistance r¹.
But the coil 13 is in circuit with the armature and it is of such a number of
turns, that it will hold the iron core in place and prevent its cutting out movement
should the current which flows in the armature circuit for any reason be excessive
and liable to injure the machine.
When the machine stops by moving the bar 19 in the opposite direction the
cam 18 will first bring the iron core into the suction coil 13 and. thus put the
resistances, successively into the armature circuit. The resistance coils r are then
successively put in and finally the armature circuit is broken; continuing the motion
a little further the field circuit is also opened and the brake now holds the machine
until the bar 19 is again moved in one or the other direction when the same
operations are repeated.
By the application of the various devices herein described, I have succeeded
in surrounding the machinery used in electric elevators with such safeguards as
will absolutely protect the electric motor therein from any possibility of damage
which would arise from an abnormal current, if the same were permitted to flow
through the armature. As will be seen, when it is desired to start the motor,
the circuit is first closed under such conditions that a considerable resistance
is in series with the armature, which resistance is gradually diminished as the
speed of the armature rises. It will also be observed that from the first
moment of closing the circuit until the maximum has been reached the field
magnet coils receive a maximum current and the result is that during all periods
of operation of the motor the field magnet is at a maximum strength. The
automatic safety device is of special importance. The lever 14 which carries
the core is so arranged that should any mechanical accident happen, such, for
instance, as the derangement of the switch gearing the system will gravitate
into the position shown in Fig. 6, by suitable arrangement of the centre of
gravity of the swinging system. In such case if no current was being supplied
to the armature, no harm would occur, but if there was a current in the
armature winding, the suction coil would promptly draw the core inwardly, and
put in the resistance required for reducing the current to a safety limit. In
this position shown in Figure 6, all of the resistance coils are included in
series in the armature circuit, which is the proper position for starting the
motor in operation. There is an enforced position for the system due to the
limitation on the movement of the elbow crank lever 14, 17, by the circular
portion of the cam 18, which compels the brush 15 to remain in such position

page_text: as to include all the resistances when starting and stopping the motor. But
in starting, after a certain movement of the brushes m, m³, m", has taken
place, the cam has been mechanically turned to a position which releases the
system from this mechanical restraint, and thereafter the position of the brush 15
on the blocks 16 is determined automatically by the main current which flows
through the armature, which in turn is dependent on the speed at which the
armature is rotated. In stopping the motor the movement given the cam 18,
mechanically, causes the circular portion of the cam to compel the swinging
core to resume its position of safety with the brush 15 in the position shown in
Figs. 6 and 10. The result is very important as stated, and positively prevents
the occurrence of any set of circumstances which would tend to cause the flow
of a destructive current through the coils of the armature.
The automatic stopping of the car D, when near the upper and lower limits.
of its travel is conveniently effected by means of the obstructions or balls a on
the operating rope. Should the operator for any reason neglect to control the
motor, suitable projections on the car will strike these limit stops a and the
further movement of the car will cause the required movement of the operating
rope and effect the movement of the bar 19 as hereinbefore described, thereby
bringing the switching mechanism into operation and applying the friction brake
on the shaft of the motor. It is to be understood that this automatic operation
of the switch, by or through the movements of the car, in no manner pertains
to the operation of a switch which is automatically moved or restored from its
operative position to its normal or inoperative position by means of devices
which are operative wholly independently of the car, or its movements, as in
certain electric elevator organizations, devised by Mr. Otis, of Yonkers, New
York, and disclosed by him in sundry applications for Letters Patent contem-
poraneous with mine.
In the arrangement so far shown I have used three brushes m, m³, m".
Brushes m' and m" have been used to cut out and reverse the current of the
the circuit of the
armature, and the brush m has been used to close and open brush is moved a
field coils of the motor. When, for any reason, this
short distance only from the edges of the plates 11 or 12, or is moved but
slowly therefrom, it may happen that an arc is formed and may be maintained
for some time, and the brush may thus not only fail to fully open the circuit
when desired but may also be more or less damaged by the formation of
the arc.
To avoid this I have substituted the modified form shown in Figs. 11, 12, 13 and 14,
in which the switch is operated partly by hand and partly by a spring, the
hand movement bringing the mechanism into such position that the required
movement of the field switch is carried on by means of the power stored in the
spring. I have for this purpose discarded the plates 11 and 12 and substituted
for them two blocks 30, 30, suitably mounted on the frame work, and for the
brush m I have substituted the metallic bar 31. The two blocks 30 are in
circuit with the generator in the same relations as the plates 11 and 12 herein-
before described, and the bar 31 is connected with the other terminal of the
generator. The circuit of the motor is closed into the line whenever the bar 31
is placed in contact with either of the blocks 30 and at any intermediate point
between these two positions the circuit is open.
I prefer to construct and operate this device as follows: Upon the shaft /
heretofore described, I secure the arm 32, Fig. 11, having at its outer end the
laterally projecting pins 33, 34, and on a rock shaft 36 suitably journalled I place
a wheel or cam 35 having three teeth so arranged as to engage with one or the
other of the pins 33, 34, of the arm 32. On the wheel 35 I also construct a cam
which has three suitably shaped notches, and I arrange a bell crank lever 38 having
a friction roller 37 bearing into one or other of the said notches and forced therein
by a spring 39 of sufficient tension for the purpose. In the position shown in
Fig. 11, the roller 37 is bearing into the middle notch and the arm 32 has its

page_text: pins 33, 34 midway between the teeth on the wheel 35. In this relation of the
parts the metallic bar 31 occupies the position of open circuit and no current flows
from the line through the coils of the motor. If, now, the arm 32 is moved to one
side by the rotation of the shaft l, as hereinbefore set forth, one of the pins 33, 34,
will come in contact with the middle tooth on wheel 35, and if such motion continues
will cause the wheel 35 to turn, thereby rotating shaft 36 and moving the bar 31
accordingly. As the motion continues the roller of the bell crank 38 rotates up the
side of the adjacent notch on the cam until it has reached the highest point, when
the spring will cause the wheel 35 to move rapidly in the same direction, thus
swinging the switch bar 31 into contact with one of the blocks 33 or 34 and thus close
the circuit of the motor. The arm 32 as already described may now continue its
motion along with the brushes m', m", but when the motor is to be stopped and the
motion of the arm 32 has been reversed by shaft the pins will again engage
with the teeth on the wheel 35, and the action just described again takes place by
the roller 37 rising on the cam to the highest point, and the further movement causes
the spring 39 to exert its force and throw the wheel 35 and with it the bar 31
I thus secure a
into the position of open circuit, as shown in Fig. 11.
rapid motion
in both closing and opening the circuit of the motor and prevent the formation of
any arc at the point of opening and closing.
In Figs. 11, 12, 13 and 14, the connections are shown in such relations that the
whole current flows through the switch 30, 31; but this is not necessary, as obviously
the former arrangement can be adopted equally well, and the switch 30, 31, used
for the field magnet circuit only.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, as communicated to me
by my foreign correspondent I declare that what I claim is :-
1. In elevator machinery, the combination, with the travelling car or platform,
of an electric motor adapted to both hoist and lower the car, a movable switching
device adapted according to its position to open and close the motor circuit,
and admit current, in respectively opposite directions through the armature circuit
and means on the car or platform for controlling the position of said movable
switching device.
2. In elevator machinery, the combination, with the travelling car or platform,
of an electric motor adapted to both hoist and lower the car, a movable switching
device adapted according to its position to open and close the motor circuit
and to admit current in respectively opposite directions through the armature
circuit, and means for mechanically varying the current in the armature circuit.
3. In elevator machinery, the combination, with the travelling car or platform,
of an electric motor, a movable switching device adapted according to its position
to open and close the motor circuit and to admit current in respectively opposite
directions through the armature circuit, and means for automatically controlling the
current in the armature circuit dependent for operation on the strength of current
flowing therein.
4. In elevator machinery, the combination, with the travelling car or platform,
of an electric motor, a movable switching device adapted according to its position
to open and close the motor circuit and to admit current in respectively opposite
directions through the armature circuit, means for mechanically varying the current
in the armature circuit during the first movement of said switching device, and
mechanism adapted to be placed in operative position by the continued movement
of said switching device, for automatically controlling the current in the armature
circuit dependent for operation on the strength of current flowing therein.
5. In elevator machinery, the combination with the travelling car or platform,
of a shunt wound electric motor, adapted to drive the same; a movable switching
device adapted to close the field magnet circuit; a resistance in the armature
circuit, and means for in part automatically controlling it, these operating, (while
the field magnet circuit is kept closed,) to first interpose resistance in the armature

page_text: circuit, then to remove a part thereof, and, finally, to automatically cut out the
remainder of the resistance; and means on the car or platform for controlling the
position of the switching device.
6. In elevator machinery, the combination, with the travelling car or platform,
of an electric motor adapted to drive the same, a movable switching device adapted
according to its position to open and close the motor circuit and to admit current in
respectively opposite directions through the armature circuit, means for mechani-
cally varying the current in the armature circuit, and means on the car or platform
for controlling the position of said movable switching device.
7. In elevator machinery, the combination, with the travelling car or platform,
of a shunt wound electric motor, a movable switching device adapted according to
its position to open and close the armature circuit thereof and spring controlled
mechanism dependent for operation upon the action of said switching device and
arranged to suddenly and widely open the field magnet circuit when required.
8. In elevator machinery, the combination, with the travelling car or platform,
of an electric motor adapted to drive the same, a movable switching device adapted
according to its position to open and close the motor circuit and admit current in
respectively opposite directions through the armature circuit, and a rope or cable
along the path of the car or platform operatively connected to said switching
device.
9. In elevator machinery, the combination, with the travelling car or platform,
of a shunt wound electric motor adapted to drive the same, and a movable switching
device, and a resistance in the armature circuit, said switching device adapted first
to close the field magnet circuit, then to close the armature circuit through a
resistance, and finally to gradually cut said resistance out of the armature
circuit.
10. In elevator machinery, the combination with the travelling car or platform,
of a shunt wound electric motor adapted to drive the same; a movable switching
device; two independent resistances adapted to be included in the armature
circuit, and interposed mechanism, including a helix or solenoid, and its core,
whereby in starting the motor, the switching device first causes a closure of the
field magnet circuit; second, a closure of the armature circuit through both of said
resistances, and then gradually cuts out one of them, and, finally, leaves the other
resistance subject to control by the helix which is variably operated according to
strength of current in the armature circuit.
11. In elevator machinery, the combination, with the travelling car or platform,
of a shunt wound electric motor adapted to drive the same, a resistance in the
armature circuit, a movable switching device adapted first to close the field-
magnet circuit, then to close the armature circuit through the resistance, and
finally to gradually cut said resistance out of the armature circuit, and means on
the car or platform for controlling the position of said switching device.
12. In elevator machinery, the combination, with the travelling car or platform,
of an electric motor adapted to hoist and lower the same, a movable switching
device for closing and opening the motor circuit, a mechanically operated friction
brake in operative relation to the motor shaft, a single controlling device operatively
connected to both the switching and brake devices, and a line or rope on the car
or platform for operating such single controlling device.
13. In elevator machinery wherein the movement of the car is effected by an
electric motor in which the energizing current is controlled by a mechanically
operated switch board and rheostat, the combination therewith of a helix in the
armature circuit, a movable core therefor, a variable safety resistance adapted to
be interposed in the same circuit and a shifting contact for said resistance
operatively connected to the movable core.
14. In elevator machinery wherein the movement of the car is effected by an
electric motor in which the energizing current is controlled by a mechanically
operated switch board and rheostat, the combination therewith of a helix or
solenoid in the armature circuit, a core adapted to movement into and out of said

page_text: helix and mechanically connected to the contact arm of said switch-board, an
additional variable resistance adapted to be interposed in the circuit of the
armature, a shifting contact for said resistance attached to the movable core, and
means connected with and operated by the switch mechanism for first forcibly
retaining such additional resistance in the armature circuit during a predetermined
movement of the switch arm and then releasing it from the mechanical restraint
and controlling it by the attraction of the said helix.
15. In a reversing switch for electric motor circuits, the combination of a movable
arm, contact blocks in the path of movement of said arm on both sides of its
neutral or open circuit position, other blocks which provide for reversals of
current, and a series of resistances interposed between the first named blocks on
one side, and circuit connections coupling corresponding blocks together, whereby
a single set of resistances serves for currents in opposite directions according to
the position of the arm.
16. In a reversing switch for electric motor circuits, two circular ranges of
contact blocks, each composed of four blocks, and the blocks of both ranges
symmetrically arranged as to position, in combination with two brushes insulated
apart and adapted to move together one over one range of blocks and the other
over the other range, and circuit connections to the said blocks so arranged as
to effect a reversal of current in said circuit when the brushes move from block
to block.
17. The combination, substantially as hereinbefore described, of elevating
mechanism including a travelling car; an electric motor for operating said
mechanism; current controlling devices or switching mechanism, by means of
which the electric current may be varied, and also reversed in the armature
circuit; means for cutting off said current, which are automatically operated
through or by the movement of the car; and means in the car for mechanically
operating the switching mechanism in either direction.
Dated this with dan
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.