US820499A - Electric-elevator-control system. - Google Patents

Description

No. 820,499. PATENTED MAY 15, 1906.

J. D. IHLDER. ELECTRIC ELEVATOR CONTROL SYSTEM. APPLICATION FILED MAR.18,1906. RENEWED NOV.24, 1905..

INVENTOR ATTORNEYS ix 8 m $6 1 EN a M R its WITNESSES:

UNITED PATENT OFFICE.

JOHN D. IHLDER, OF NEW YORK, N. Y., ASSIGNOR TO OTIS ELEVATOR COMPANY, OF EAST ORANGE, NET V JERSEY, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented May 15, 1906.

Application filer March 13,1305. Renewed November 24, 1905. Serial No. 288.853.

To (1,7 7 whom it 'IN/(J/y concern:

Be it known that I, J OHN D. IHLDER, a citizen'of the United States, and a resident of New York city, in the county of New York and State of New York, have invented certain new and useful Improvements in Electric-Elevator-Control Systems, of which the following is a specification.

My invention relates to the control of elevators, and more particularly to the control of electric elevators, and has for one of its objects to provide means whereby the elevatorcar may be brought to rest at any predetermined point in the path of its travel either by the car-operator or by automatic means independent of the operator and making it possible to effect a landing or stop exactly at the desired point regardless of the load, speed, or direction of travel of the elevator-car and not depending upon the skill of the operator to ejll ect such landing.

My invention further consists in the construction. and arrangement of circuits hereinafter more fully described, and shown in the accompanying specification and drawing.

The drawing represents more or less diagrammatically an electric-elevator system embodying my invention, and in which and designate, respectively, the positive and negative mains of a source of ourrent-supply.

10represents what I shall call a potentialswitch.

20 is amagnet which controls a number of contacts operating to introduce or cut out, as the case may be, the speed-controlling resist ance 30 and the series field 40.

50 designates a magnet-switch which controls the resistance 35, the extra field 70, and a circuit to the contact 8. The small magnet controls the circuit to the magnet 60. This latter magnet 60 operates to short-circuit the resistance 90, which is in series with the extra field 70.

represents the shunt-field, and the hoisting-motor armature, having the brushes 111 and 112.

and are magnets controlling various circuits leading to the brakeunagnet and the motor-armature 110.

is a mamrally-operable switch and may be advantageously placed. in the elevatorcar. designates a safety-switch, also op erated by hand.

200 and 800 are the top and bottom limitswitches, respectively, and operate to stop the elevator-ear should it for any reason overrun its normal travel.

Having described very briefly each of the several parts shown on the drawing, I will now go into a more detailed description of these parts and at the same time trace the various circuits.

The fine black lines represent the operating, brake, and shunt-field circuits, while the heavy black lines designate the main and motor circuits, the extra field-circuit being shown by a black line of medium thickness.

The potential-switch 10 is shown held in its upward position against the tension of a spring (not shown) by the magnet-coil 11 and plunger 12, this latter being fastened to the insulator 4. This switch has two arms fastened together by the insulation 4 and pivoted about the rod 5. These arms carry at their upper ends contacts 1 and 2, which serve to connect the and mains of the source of supply with the wires 7 and 6, respectively, when the switch is in its upper position. With the switch in this position the main is'connected also to the small fixed contact 3. At the lower end of this switch is a.contaet 8, insulated from the switch and adapted to engage the fixed con tact 9 directly under it when the magnet-coil 11 is deenergized, thereby allowing the switch to drop to its lower or open position. The limit- switches 200 and 300 are normally closed, holding their respective contacts in electrical connection either by a weight or spring and when operated by the car overrunning its travel open the circuit to the potential-switch coil 11 through the wire 14. This wire 14 is connected to the main by wire 6 when the switch is in its upper or closed position. The other terminal of the coil 11 is connected through the small resistance 13 and switch 190 to the wire 7. The 11 otential-switch. 10 is closed by hand, after which it will be held. in its upper position by the coil 11 so long as there is sufi'icient potential in the main line. The circuit to the magnet 11 may also be opened by the operation of the safety-switch 190, its circuit to the line being thus broken.

The wire 7 is connected to the fixed. contacts 15, 17, 18, and 21, directly under which contacts are movable contacts 22, 23, 24, and

25, respectively. The contacts 22 and 23 are mounted on the insulation 26, which is carried on the upper end of the rod 28. In a similar manner the contacts 32 and 33 are mounted on the insulation 31, which is also carried by the rod. 28. At the lower end of the rod 28 is fastened the plunger or solenoid-core 29, adapted to be raised by the magnet-coil or solenoid 130 whenever the latter is sufficiently energized. As the plunger is raised it will carry the rod 28 and. insulating- pieces 26 and 31 upward, together with the contacts mounted thereon. The contact 22 will make contact with the contacts and 16, while the contact 23 will be electrically connected to the contact 17. The raising of the rod 28 will also break any connection that may exist between contacts 32 and 34 and 33 and 36, respectively. Contacts 32 and 34 and 33 and 36 are in contact when the plunger 29 is in its lowermost position.

In order to trace the circuit to the motor, it will be necessary to energize either the coil 130 or 120. Let it be supposed that the coil 130 has been energized to raise its plunger 29. By virtue of the connections established current will flow by way of the+main and wire 7 and contact 15 to the contact 22. The Contact 22 is connected by wire 37 to the contact 38, since the switch of coil 120 is in its lowermost position when the switch of coil 130 is in its uppermost position. Therefore contact 36 is at this time in contact with the contact 39. These two magnet-switches controlled by the magnets 130 and 120, respectively, have a mechanical connection between them which is not shown on the drawing, but is most fully described in a former patent issued to me on July 8, 1902, No. 794,336. It will therefore be sufficient to state in this connection that owing to a mechanical connection between said switches in the form of a rocking beam one switchplunger, such as 29, when raised by its magnet moves the other switch controlled by the magnet 120 to its lowermost position. The switch thus moved willestablish connections between the contacts mounted on the lower insulating-piece and the fixed contacts directly below these movable ones, respectively. Thus when one switch is operated the other switch is always moved to its lowermost position, this mechanical connection preventing both switches from being moved to either their lowermost or their uppermost position at the same time. The circuit from wire 37 is continued through wires 41 and 42 to the motor-armature brush 112. Passing through the motor-armature 110 the circuit goes by brush 111 to wire 43 and through contacts 44 and 45 to the wire 46. Follow ing this wire to the right this circuit can be traced to the speed-controlling resistances and 30. The right-haml terminal of these resistances is connected to one side of the series field 49 by wire 47, the other end of the series field being connected to then1ain 6. It will therefore be seen that a circuit has been completed from the+main to the main, including the motor-armature, the speed-controlling resistance, and the series fields. The shunt-field 100 has one side connected by wire 37 and contact 22 to the other main 7 and the other side directly to the negative ormain 6. hen the contact 22 engaged the fixed contacts 15 and 16, a circuit was established to the magnet-coil 01' the iralze 140 by the wire 51 and resistance 52, and as the brake-coil has its other terminal 56 connected to the small contact 3 of the potential switch the brakemagnet, together with the resistance 52, will form a shunt-cir cuit across the main line, receiving current at the full-line potential. The magnet-coil 140 will be fully energized and operate to raise the plunger 53, carrying the weighted. brake-shoe 54 away from the friction-pulley 55, said trictionpulley being pre'lerably mounted on the motor-shaft.

The extra field. '79 has one terminal conncct ed by wire 37, contacts 38 and 39, and wires 41 and 42 to the brush 112 of the motor-armature. The other terminal of the extra field is connected by wire 64 to the extra field resistance 90, which in. turn is connected by wire 63 and flexible cable 62 to the contact-plate 59. This contact-plate is in electrical connection with the fixed contact 58, which is connected by wires 57 46 and contacts and 44 and wire 43 to the armaturebrush 111. It will therefore be seen that the extra field 70, having the resistance 90 in series with it, is connected across the armaturebrushes and is therefore in shunt to the motor-armature.

It has been shown that when the coil 13() is energized to raise its plunger 29 certain connections will thereby be established which will cause the brake to be released and the hoisting-motor to be set in motion. Now in order to show how the coil 130 was energized it will be necessary to describe the operation of the manually-operated switch 160 and the floor-controller 150. The floorcontroller 150 comprises a number of conducting-strips suclii as 119, 121, 128,124, 87, &c.preferably made of copper and rigidly fastened to a base of some insulating material. Slatc might be used to advantage for this purpose. The conducting-strips, togethcr with the insulatingbase, are arranged so as to be revolved about a central 'lixed axis by some moving part of the elevatormachine. One way to accomplish this would be to connect a large sprocket-wheel on the floor-controller by means of a chain to a small sprocket-wheel keyed to the drumshalt, so that the tloor-controller would have a relatively slow motion. Adjacent to the path of travel of the several conducting- 1 o 820,499 I gig strips are placed lived insulated contacts or brushes, such as 1.22, 101, 103, 88, 127, &c. These are adapted to engage or disengage the strips whenever the latter are revolved so as to make or break contact with them.

The manually-operable switch 160, which, as before stated, may be located in the car or in the near vicinity, comprises a pivoted lever 65, which is adapted to pass over and make contact with the metallic contact strips 66 67 68 69 71 73, &c., these latter being rigidly fastened to some insulating-base, such as slate. The contact-strips 68 and 73 are electrically connected together, and by the wire 76, switch 190, and wire 72 are connected to the positive main 7. These two strips therefore constitute the positive feed -to the switch 160. In moving the lever 65 to the left it will engage the contact-strip 66. This operation merely connects the lever 65 with the wire 74 and produces no further results. On further moving the lever to the left it will engage also the contacts 67 and 68. This operation will result in connecting together the wires 74, 75, and 76 that is, the wires 74 and 75 have been connectei to the positive main. 74 is connected to the brushcontacts 77, 78, 79, and 84, these four brushes being in contact with the contact-strip 85 in the position of the floor-controller, as shown on the crawing. For the time being there will be no further circuit through the wire 7 4. By way of Wire 75 and contact-brush 86 connection is made to contact-strip 87. Contact is made between brushes 86, 88, and 125 by means of the contact-strip 87 and the intervening brushes and their connections. The wire 89 connects the contact 88 and one terminal of the magnet-coil 130, the other terminal of this coil being connected by wire 91 to the-main. A circuit is therefore es tablished through the coil 130 when the arm 65 is moved into contact with the strip 67. The said coil 130 will raise its plunger 29, which, as before pointed out, will operate to start the motor and hoisting machinery to raise the car. The motor will run at slow speed, however, since its armature receives current at a potential considerably lower than the simply-mains, owing to the resistances and being in series with the armature of said motor, and since the three field-windings are excited they will produce a much more powerful magnetic field than is required to run the motor at its normal spee', thus further tending to keep the motor at a low rotative speed. The acceleratinganagnet 20 controls the operation of the five contacts 92, 93, 94, 95, and 96, which are pivotally mounted and when energized by the magnet-coil 20 are brought into contact, respectively, with the contacts shown directly above the movable contacts. These movable contacts may be placed at di'llerent distances from the magnet 20 111 order that they shall operate consecutively in some prearranged order. One terminal of the magnet-coil 20 is connected to the wire 37,which wire is connected, as before pointed out, to the armature-brush 112 when the magnet 130 is energized. The other terminal of the magnet-coil 20 is connected through the contacts 97 and 98 to a point 99 on the speedcontrolling resistance 30. From here by way of the resistance 85 and wire 46, contacts 44 and 45, and wire 43 there is a connection to the armature-brush 111. Therefore the magnet-coil 20 forms a shunt to a circuit comprising the motor-armature, resistance 85, and a very small portion of the resistance 30. When current is first put onto the motor, the same being at rest, the voltage across the terminals of the magnet-coil 20 will be low, owing to the manner in which it is con nected. As the motor, however, accelerates in speed this potential will gradually rise, and the contacts 92, 93, and 94 will operate in their numerical order to cut out or short-circuit the resistance 30. The contact 95 in this manner cuts out a portion of the series field 40, and the contact 96 cuts out or short-circuits the remainder of the series field. The motor will now run at a somewhat higher speed, having had the greater portion of the resistance in series with it cut out and having had its series fiell short-circuited.

The speed-magnet is energized when the operator moves the lever to its extreme position-that is, when the said lever 65 connects the contact-strips 68, 69, and 71. Current will then flow from the positive wire 76 to contact 71, contact-brush 101, and the contact-strip 102 will become alive. Bearing against this contact-strip 102 is the brush 103, which by wire 104 is connected to one terminal of the coil of magnet 50. The other terminal of this magnet is connected. by the wire 106 to the negative main 6. The

coil of magnet 50 will by reason of being con- 7 nected across the positive and negative mains, through the operating-switch 160 and floor-controller 150, become energized and will raise its plunger 105, carrying on its upper end the contact-plates 107 and 59. These contact-plates are rigidly mounted upon an extension of the magnet-plunger 105, but insulated from it. They are adapted to make or break contact with the fixed contacts 108, 109, 58, and 61. These fixed contacts are adjacent to the path of travel of the plates 107 and 59.

62 designates a flexible cable which is connected to the contact-plate 59 and wire 63.

As soon as the magnet-switch 50 has been energized the contact-plate 107 will establish a connection between the fixed contacts 108 and 109, which will short-circuit or cut out the resistance 35 and at the same time open the connection between the fixed. contacts 5S and 61 and also break the connection between the contact 58 and the wire 63. This last-named operation will open the circuit supplying the extra field through the resistance 90. The motor will now run at its normal full speed, having all of the resistance in series and the armature resistance, together with the series field, short-circuited. and having the extra field circuit broken at the contact 58, the motor-field being new excited by the shunt-field only.

As the car approaches a landing at which it is desired to stop the operator will bring the switch-lever 65 back until it breaks connection with the contact-strip 71. This will at once deenergize the coil of magnet-switch 50, allowing the plunger to drop and cause the contact-plate 107 to disconnect the fixed contacts 108 and 109 and by so doing to insert the resistance 35 in the armature-circuit. At the same time a circuit will be made through the resistance 90 and extra field 70, which will cause the motor to slowdown to a considerable extent by reason of the increase of field magnetization and the shunting of current from the armature through this circuit. By bringing the switchlever 65 to the center or otl position the circuit to the coil 180 will be broken, the plunger 29 will drop, and thus the supply-current will be shut oil from the motor. The extra field, having the resistance 90 in series with it, being connected as a short shunt across the armature-brushes, will be energized by the current generated by the revolving armature, which will thus produce a powerl'ul dynamic brake, which action, in conjunction with the frictioinbrake controlled by magnet 140, will quickly bring the motor and hoisting machinery to rest.

Thus far little has been said about the operation of the floor-controller 150 but a more detailed description will now be given.

As illustrated in the drawing, the floor-controller is designed for six floors or landings. This number, however, may be more or less. As previously described, the floor-controller contact-strips, together with their insulated base, are slowly revolved one way or the other, depending upon whether the elevator-car is ascending or descending. In order to describe the operation of this floor-controller, it will be assumed that the elevator-car is somewhere between the third and fourth floors. The floor-controller, as shown, corresponds with such aposition ot the elevator-car. It will further be assumed that the elevator-car is traveling upward at full speed, the lever 65 being in the extreme left-handposition and the floor-controller being slowly revolved in a counter-clockwise direction. Suppose the operator in the car wished to have the car stop automatically at the fourth fioor. To do this, he merely brings the operating-lever back toward the center until it engages the three contact-strips 67, 66, and 68. As soon as the lever 65 passes 011' the contactstrip 71 it causes the magnet-coil of 50 to drop its plunger, and thus, as has been previously pointed out, insert the resistance 35 into the armature-circuit and at the same time energize the extra field 70. This will reduce the speed 01 the elevator-car, and about this time the floor-controller has revolved into such a position that the contact-brush 79 has been brought into engagement with the small contact-strip 110. The strip 110 is connected to the circular strip 1.11 which engages at all times the contact-brush 127. The brush 127 is connected by the wire 113 to one terminal of the magnet 80, its other terminal being connected to the negative main, 6. A circuit through the coil of magnet 80 is therefore established and the contact 82 will be drawn against the action of the spring 83 into con tact with the fixed contact 81. This will place the magnet 60 across or in shunt to the n'iotor-armature, causing the magnet 60 to be energized and to operate its contacts in a well-known way to short-circuit the resistance 90 in consecutive steps. The amount of resistance 90 being thus cut out or shortcircuitcd depends on the extent of magnetization which has been produced by the coil of magnet 60, and this in turn. depends upon the potential across the arm attire-brushes, which will be proportional to the motor speed and load carried by the elevator-car. The contact 11 1 dill'ers from the other contacts 01 the magnet 60 in that it has secured to it but insulated from it a small contact 97. This contact 97 is normally in contact with the fixed contact 98, and these two contacts complete the circuit when in such position to the accelerating-magnet 20. When, however, the contact 114 is carried upward by the magnet 60, it carries the contact 97 out of engagement with the contact 98, which will break the circuit to the magnet 20, and thereby deenergize it, thus cutting into circuit the resistance 30 and series field 40. By inserting the resistance 30 in this manner in series with the armature the current in the extra field may be kept to a much lower amount than would be possible were the series resistance 30 not included in the arniature-circuit and acting in conjunction with the extra field 70. The current [lowing through the extra field 70 will depend upon the action of resistance 90, which is in series with it, and the load in the car will automatically regulate the resistance and resultant current, so that a predetermined slow-down speed for difl'erent loads is attained. This is fully explained in my Patent No. 710,581, granted October 7, 1902, for elevator. By this time the car has ascended until within a short distance of the desired landing or floor, and the next operation of the floor-controller will be when the brush 116 engages the small insulated contact-strip 1 17.

This strip not being electrically connected to anything, the result will be to break the connection between the contact-strip 121 and the wire 75. Now this wire is the positive feed for the wire 89, which is one terminal of the magnet-coil 130, being connected by brush 88 to the contact-strip 121, which has :lirst been rendered dead. The brush 122, which also is in contact with the strip 121, being connected to the contact 69 of the operating-switch, is open-circuited at that contact. Therefore the brush 122 cannot furnish current to the contact-strip 121, and since the contact-brush 88 can only be supplied with current from the brush 86 when the various parts are in the position which has been assumed the circuit to the magnet-coil 1.30 will be opened and its plunger will drop, cutting oil the supply of current to the motor, the motor-circuit being broken at the contacts of the switch connected to said plunger. The circuit of the brake-magnet is at the same time broken, causing the friction-brake to be applied. It the operator should at any point of the car travel. leave the switch-lever in either of its extreme positions, so that the contacts 71, 69, and 68 are connected, the car will continue to ascend or descend until stopped automatically either at the top or bottom floor by the action of the floor-controller. If the switch be brought to such position that the contact-strips 6S and 69 are engaged by the lever 65, the car will ascend or descend at slow speed until the floor-controller switches automatically effect the slowdown and stop at the top or bottom floor. In other words, the car will stop automatically at the desired limits of its travel through the action of the floor-controller,whether the car has been traveling at fast speed or slow speed, unless the operators lever has been moved to the automatic position or to the center or oil position to stop the car at some intermediate point.

Let it be supposed that the car is running up at lull speed, the lever 65 being left in its extreme left-hand position. the automatic stop will then be when the car is some distance away from the landing The contact-strip 102 will then run on: of the contact-brush 101. This will deenergize the contact-strip 102, and consequently the brush 103, which engages it. The brush 103 is connected. to the magnet-coil 50, whose circuit is broken at the controller. The switch controlled by the coil will then operate to reduce the speed of the traveling car. As the car ascends still farther, but at a reduced speed, the next operation 01 the floorcontroller will be when the contact-block 124 passes under and engages the contact-brush 125. This will at once establish a circuit to the magnet through contact-brush 127. Magnet 80 will be energized to close a circuit through contacts 81 and 82 and. the magnet small portion of the resistance 90.

The first step of,

60, the said magnet and the parts operated thereby being the means for adjusting the speed of stopping in accordance with the load. The last step of the floor-controller occurs when the block 121 passes from under the contact-brush 122, causing the circuit to the magnet-coil 130 to be interrupted and the car to be stopped.

In the event of the potential switch being thrown manually while the elevator is running, the mains 6 and 7 would be entirely disconnecten from the source of current-supply. The knife-contact 8 would in this case engage the fixed contact 9, and the extra field would. at once be energized through a The opening of the switch 10 also opens the circuit to the brake-magnet 140 at the contact 3, and the hoisting-motor will at once come to rest. The potential. switch will operate to stop the hoisting-motor in a similar manner should the circuit to its holding-magnet 11 be broken at either of the limit- switches 200 or 300, these limit-switches being so placed as to operate whenever the elevator-car over runs or exceeds its normal travel. The same result can be accomplishedby the safety switch 190 being opened. This switch not only opens the circuit to magnet 11 but cuts oil all curre1'1tsup )ly to the operating-switch 160.

In the description of the various operations brought about by the manipulation of the several parts either automatically or otherwise it has been assumed for the purpose of illustration that the elevator-car has been going only in an upwardly direction. Should the operating-switch lever 65, however, be moved lrom its center or off position to the right, the various operations will take place in a similar manner, except in this case the magnet-coil 120 instead; of 130 will be energized. The various motor connections will be established and the armaturecircuit will be made in such a way as to cause it to revolve in an opposite direction to what it revolved when the car was ascending. The floor-controller will now revolve in a right-handed or clockwise direction, bringing about its several connections and arrangements of circuits in a manner already described in connection with an ascending car, the operation of the floor-controller being the same for all of the floor-landings except the extreme top or bottom landings.

The magnets 20 and 60 are shown as operating a number of movable contacts directly under them. I do not wish to be limited to any definite number of such contacts, as I may use more or less. The greater the number that are used, however, the smoother will be the act of starting and stopping. The floor-controller is also shown as being comprised of a number of contact-strips mounted on a flat insulating-base. These strips might just as well be mounted upon the periphery portion of said automatic means by which.

of a drum and having the several brush-contacts pressed against them, or the floor-controller may consist of sets of stationary switches placed in the hatchway and operated in proper sequence by cams on the car to ell'ect the gradual and automatic st opping ol the car, as hereinbetore described. such case there would be a double series of switches in each set, one series of each set being operated on the downward motion of the car and the other series of each set being operated on the upward motion of the car. Furthermore, although the floor-controller is here shown for six l'loors, it may be construoted for any number of floors.

Other changes might be made in the system as diagrammatically represented on the drawing without departing from the spirit of my invention.

Therefore, not wishing to be limited to the precise construction of details as shown and described, what I claim as new, and desire to secure by Letters Patent, is

1. The combination with a car and its motor, of motor-controlling means, automatic means for stopping the car with varying loads at the limits of its travel and at any predetermined intermediate point, and means for rendering inoperative only that part of said automatic means by which the car is stopped at any predetermined intermediate point.

2. The combination with a car and its motor, of motor-controlling means, automatic means for stopping the car with varying loads at the limits of its travel and at any predetermined intermediate point, and means for rendering inoperative at will only that part of said automatic means by which the car is stopped at any predetermined intermediate point.

3. The combination ol a car and its motor, of imitor-eontrolling means, automatic means for gradually stopping the car with varying loads at the limits of its travel and at any predetermined. intermediate point,and means for rendering inoperative at will only that part of said automatic means by which the car is stopped at any predetermined intermediate point.

a. The combination of a car and its motor, of motor-control]ing means, automatic means for stopping the car with varying loads at the limits of its travel, and at any lioor-level in the traverse of said car, and means for rendering inoperative only that portion of said automatic means by which the car is stopped at any floor-level.

5.- The combination of a car and its motor, of motor-controlling means,automatic means for gradually stopping the car with varying loads at the limits of its travel and at any floor-level in the traverse of said car, and means for rendering inoperative only that the car is stopped at any floor-level.

G. The combination of a car and its motor, of motor-controlling means,automatic means connected to reduce the speed of said motor before stopping and to vary such reduction of speed in accordance with the load so that the air will stop at the limits of its travel and at any floor-level desired, and means for rendering ino ')crative only that portion of said automatic means by which the car is made to stop at a desired floor-level.

7. The combination of a car and its motor, of motoreontrolling means, automatic means for reducing the speed of said motor as the 'car reaches either limit of its travel and also as it reaches any desired. floor-level and to vary such change of speed in proportion to the duty, and means for rendering inoperative at will only that portion ol said automatic means by which the car is stopped at a floor-level.

8. The combination ol a car and its motor, of motor-controlling means, automatic means for gradually stopping said car at the limits of its travel and at the same predetermined intermediate point regardless ol the load, direction of travel or speed, and means for rendering inoperative at will that portion of said automatic means by which said car is stopped at the intermediate point.

9. The combination of a car and its motor, of motor-controlling means, automatic means for gradually stopping said car at the limits of its travel and at the same predetermined intermediate point regardless of the load, direction of travel or speed, and manually-operable means for rendering inoperative at will that portion of said automatic means by which said car is stopped at the intermediate point.

10. The combination of a car and an electric motor for operating same, with electric circuits and connections for gradually and automatically stopping said car with varying loads at the limits of its travel and at any intermediate point, means for changing the relation of said circuits and connections at will so that said car will stop automatimlly only at the limits of its travel.

1 1. The combination with a car and its motor, of means for controlling the starting, stopping or reversing of said motor, motorcontrolling means connected to reduce the speed of the motor at the limits of its travel and at predetermined intermediate points and to vary such reduction ol speed inversely to the load, and means for preventing the stopping of the car at any of said intermediate points.

12. The combination witha car and its metor, of means for controlling the starting, stopping or reversing of said motor, motorcontrolling means connected to automatically rcduce the speed of the motor at the limits of its travel and at predetermined intermediate points and to vary such reduction of speed. inversely to the load, and means for preventing the stopping of the car at any of said intermediate points.

13. The combination of an elevator-car and a motor for operating same, with motorcontrolling means, automatic means for gradually stopping said car with varying loads at any fioor level, and. means comprising a switch for rendering s aid automatic me ans inoperative except at the limits of travel of said car.

p 14. The combination of a car and its motor, with motor-controlling means, automatic means for gradually stopping said car with varying loads at the limits of its travel and at same intermediate points, electric circuits and connections comprising an electric switch for rendering said automatic means inoperative at will except at the limits of travel of said car.

15. The combination of a car and its motor, with motor controlling means, automatic means for gradually stopping said car with. varying loads at the limits of its travel and at same intermediate points, electric circuits and connections comprising a manuallyoperable electric switch for rendering said automatic means inoperative at will except at the limits of travel of said car.

16. The combination with a car and its motor, of motor-controlling means, means comprising a fioorcontroller, a single switch connected thereto, and electric circuits and connections to gradually and automatically stop said car at the limits of its travel, and at a plurality of floor-levels by the operation of said switch while the car is in motion and at a suf'lieient time before said car reaches a desired floor-level.

1.7 The combination with a car and its motor, of motor-controlling means,means comprising a floor-controller, a plurality of contacts thereon for a plurality of floors, a

switch comprising a plurality of contacts and an arm adapted to engage therewith, and electric circuits and connections, to gradually and automatically stop said car with. varying loads when the said, switch is in one position and to operate said car to the limit of its travel when said switch is in another position.

18. The combination with a car and its mo tor, of motor-controlling means, means comprising a switch and floor-controller for graciually and automatically stopping said car with varying loads substantially at the level of any floor when said switch is in one position and to' operate the car at a slow speed and. to thus stop the car only at the limits of its travel when said switch is in another position.

19. The combination of a car and its motor, with motor-controlling means, means comprising a switch and floor-controller for gradually and automatically stopping said car with varying loads at any desired floor-level when the switch is in one position and to operate said car at a maximum speed and. to thus gradually and. automatically stop the car only at the limits of its travel when the switch is in another position.

20. The combination with an elevator-car and its motor, of motor-controlling means, means, comprising a floor-controller and a switch having a plurality of? operative positions, for gradually and. automatically stopping the said car with varying loads at any floor-level after the switch is moved to one position, to operate the car slowly and. thus stop the same only at the limits of its travel when said switch is moved to another position, and to operate said. car at a maximum speed and thus stop the same only at the limits of its travel. V

21. The combination with a car and its motor, of motor-controlling means, means comprising a switch for operating said car at a maximum speed and gradually and automatically stopping said car with varying loads at the limits of its travel when the switch is in one position and for thus stopping a car with varying loads at a same predetermined posi' tion.

22. In a motor-controlling apparatus, the combination with a motor, of an extra field and variable resistance in shunt with the armature-termin als, a load'inagnet to cooperate with said variable resistance, an extra resistance in series with the armature and means for simultaneously short-circuiting said resistance, break the extra field-circuit, and prevent the said load-magnet from being energized.

23. In a motor-controlling apparatus,the combination with a motor, of an extra field and variable resistance in shunt to the armature-terminals, a load-magnet l'or short-circuiting said variable-resistance, and means for simultaneously breaking the circuit of the extra field and variable resistance and. a circuit leading to said load-magnet.

24. The combination. with a car and its motor, of motor-controlling means, automatic means for gradually stopping the car with varying loads at the limits of its travel, circuits and connections and means for changing the relation thereof when desired for automatically and gradually stopping the car with varying loads substantially level with any intermediate floor.

25. The combination with a car and its metor, of motor-controlling means connected to automatically reduce the speed of the car with varying loads before stopping substantially level with the top or bottom floors, circuits and connections and means for changing the relation thereof to automatically re duce the speed of the car and stopping the same substantially level with any intermediate floor.

26. The combination with a car and its motor, of motor-controlling means, means connected thereto for automatically changing the speed of the motor as the car reaches the top or bottom floor and to yary such change of speed in proportion to the load so that the car shall stop substantially at the lloor-letcl, circuits and connections and meansfor Changing the relation thereof so that the speed of the motor shall be automatically reduced and the car stopped at any desired intermediate 1 27. The combination with a car and its motor, of motor-controlling means connected to automatically change the speed of the motor as the car reaches the top or bottom floor and to Vary such change of speed in proportion to the load until the car stops substantially level with the floor, circuits and connections comi prising an electric switch so constructed and arranged that the speed. of the car shall be automatically reduced. and stopped level with UKJUfIUU 5 troller shall automatically control said motor-controlling means to thus stop the car substantially level with any intermediate floor when the switch is moved to automatic position.

In witness whereof I hereunto aliix my signature.

JOHN D. IHLDEH. 'itnesses:

CHARLES M. NrssnN, TAL'IER ('7. SIRANG.

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