US683924A

US683924A - Electric-elevator system.

Info

Publication number: US683924A
Application number: US72454299A
Authority: US
Inventors: Ethelbert M Fraser
Original assignee: Otis Elevator Co
Current assignee: Otis Elevator Co
Priority date: 1899-07-20
Filing date: 1899-07-20
Publication date: 1901-10-08
Anticipated expiration: 1918-10-08

Description

No. 683,924. Patented 0st. 8, |90l.

E. M. FRASER.

ELECTRIC ELEVATOR SYSTEM.

(Application led Juy 20, 1899.)

(No Model.)

UNITED STATES PATENT OFFICE.

ETIIELBERT M. FRASER, OF SAN FRANCISCO, CALIFORNIA, ASsIoNOIt, BY MESNF ASSIGNMENTS, To THE OTIs ELEi/*A'TOE COMPANY, OF

NEV JERSEY.

ELCTRio-ELEVATOR SYSTEM.

SPECIFICATION forming part of Letters Patent No. 693,924, dated octobe 8, 190i.

Application filed July 20,1899.

T0 all whom it may concern:

Be it known that I, ETHELBERT M. FRASER, of the city and county ot' San Francisco, State of California, have invented certain new and useful Improvements in Electric-Elevator Systems, of which the following is a specification.

My invention has reference in general to the operation of machinery by electric power, but relates more particularly to an elevator system in which the car is operated by means of two electric motors that are capable of being driven at the same and also at relatively diierent rates of speed, the construction and arrangement of parts being such that the car remains stationary when the motors are both running at the same speed, but moves either upward or downward when the relative rates of speed of the motors are changed, so that one of them runs either faster or slower than the other. Such a system is exemplified in United States Patent No. 610,481, granted to me September 6, 1898, for an improvemeutin elevators. In addition to the car and the two motors and their necessary equipment of cables, sheaves, driving-pulleys, and other parts illustrated in said patent the elevator system herein shown and described includes a starting apparatus, such as illustrated in United States Patent No. 655,355, granted to me August 7, 1900, whereby automatic means are provided for gradually and smoothly starting and stopping the elevator-motors, an automatic brake, which may be applied to the hOisting-sheave and electrical means for withdrawing the same, and electrical means controlled from the car for varying or restoring as required the normal speed of either motor. The starting and stopping apparatus is controlled either from a switch on the car or from a switch in the building in which the elevator is placed, the latter switch being merely auxiliary and designed for use when the motors are run without running the car for the purpose of inspecting or testing machinery, 85o. The starting and stopping switch on the oar is so arranged with reference to a switch controlling the action of the brake that both are operated together, while an automatic switch controlled by the startserai No. 724,542. (No modali ing apparatus prevents the removal of the brake until the motors are started, the brake being allowed to return before the motors are stopped. The arrangement of apparatus and circuits in my system is such that the relative speeds of the motors cannot be varied until they have attained normal speed, nor can they be stopped after the speed of either one has been varied until they have been brought back to normal speed and are both runningat the same number ofrevolutions per minute. While the speed of either motor is maintained constant the speed of the other may be varied by varying its field magnetization, one or more field-coils being short-circuited or again thrown into circuit, as desired, and controlling means are provided upon the car for varying the strength ot' the fields in this manner or for restoring normal conditions of running.

The accompanying drawing is a diagrammatic representation of the preferred form of my invention, showing the two motors with their armatures in parallel, the Inotor fieldcireuits, the arrangement of circuits for the starting 'and stopping apparatus, the brakecircuit, a car, a controller on the car for varying the number of coils in the respective field-windings, and also a simultaneously-operated starting and stopping switch and brakeswitch on the car.

In the drawing A represents the elevatorcar, which may bea passenger-car of any approved design and construction or a hoisting cage or platform of any kind, my invention being applicable to all forms of hoisting mechanism.

B and C are two electric motors of any suitable constrnction employed to operate the elevator-car, I having shown bipolar shuntwound motors. The armatures are connected in parallel, while the two field-windings of each motor are connected in parallel with each other; but the entire field of one motor is connected in series with that of the other.

X W and Y Z represent the field-windings of the motors B and C, respectively, X being in parallel with W and Y with Z, but X W in series with Y Z.

The automatic starting and Stopping ap- IOO paratus, as described in the patent hereinbefore referred to, consists, essentially, of the comparatively lowr resistance solenoids N P Q in series with the armature-circuit, the rheostats E F, also in series, the movable cores R,S, and T, carrying the cone-shaped contacts G, H, and J, adapted to make contact with the fixed contact-pieces K,L, and M, respectively, and in multiple shunt with the series coils of the high-resistance solenoids O, U, and V.

The solenoids N and O are so wound that when energized they both tend to attract the core R upward; but solenoids P U and Q V are so wound andthe current passes through them in such direction that when energized P and Q always tend to hold their respective cores S and T downward, while U and V tend toattract the cores upward, the solenoids P and Qupon first starting being stronger in attractive force than U and V. On the tops of the cores R, S, and T are contact-pieces i" s tu fu, adapted to make contact with the springcontacts between which each is placed, respectively, when the cores are raised. Pieces 'r, s', t, and u are normally out of contact with their respective springs; but t is normally in contact with springs t' fu" and is moved out of' contact therewith when core T rises. The armature-circuit, including the series solenoids and rheostats, is indicated in heavy black lines, and current is suppliednthereto from the mains indicated at -land on the right of the diagram. The starting apparatus is controlled from the elevator-car by means of a switch D or from an auxiliary switch D outside of the car. Presuming D to be open, should switch D be closed a circuit would be completed from the positive main at 1 by wire 2 to the point 2 and from there by a shunt 3 around the lamps y y or other high resistance to spring/v through contact-piece fv to spring t", from thence by wire 4 to the point 4', by wire 5 to the high-resistance solenoid O, and by wire 6 to switch D', through the switch andby wire 62 to wire 5",` and thence to the negative lead at binding-post 10. Solenoid O being energized attracts its core R upward and closes the armature-circuit between G and K as follows: Current entering from the positive lead at 1 passes by the wire 1l to binding-post 12 and through a flexible connection 13 to contact-piece G, thence through fixed contact 'K and by wire 14 to rheostat E, from thence by wire 15 to vSolenoid P, by Wire 16 to rheostat F, by wire 1'7 to solenoid Q, by wire 18 to solenoid N, by Wire 19 to binding-post 20, connecting with one brush of motor C, thence through the armatures of the motors B and C in parallel to binding-post 2l, and back by wire 22 to the negative lead at 23, thus completing the armature-circuit. A circuit is simultaneously completed throughpthe iield-windings, starting from the point 24 on wire 14 justV above rheostat E. The field-circuits are shown in heavy dotted and dashed lines. From 24 the current passes by wire 25 Ato a I suitably-insulated binding-post 26l on motor" B, from whence it divides, part passing by wire V2'7 through coil W to binding-post 28 and by wire 29 through the cable 30 to binding-post 3l, and part passing by wire 32- through coil X, also to binding-post 31. Wire 33 vconnects vbinding-post 31 with bindingpost 34 on motor C, where the current again divides, part passing by wire 35 through cable 36 to binding-post 37, and thence through winding Z to binding-post 2l in the armaturecircuit and out to the negative lead, and part passing from the post 34 directly through windingY and by wire 38 to post 21. Apart of the field-current also passes through a shunt-circuit, including a field-controlling switch, on the car. This shunt-circuit will be herenafter'descrihed in connection with the system of field-control, it being sufficient v to state here that it in no way affects the relative speeds of the motors. The armature and field circuits being energized, the-motors will start, with the rheostats E and F in series with the armatures, and will tend* to speed up, both running at the same number of revolutions per minute. The core R having been attracted upward -by the joint action of solenoids O and N causes contactpiece r to bridge springs 1" r, and therefore coil U is energized, the current entering the solenoid at the point 5' on wire 5 and returni ing to the negative lead at post 10 by wire 5". The attractive force of solenoid P having been somewhat weakened by the counter electromotive force produced by the motors is now overcome by solenoid U acting in opposi tion, and core S is attracted upward, bridging the springs s. s" and causing contact H to close on contact-piece L, thus short-circuiting rheostat E and solenoid P, the current now passing directly from wire 11 at 11 to contact I-l and to the armatures as before. The bridging of springs s s" throws solenoid V into circuit, which attracts core T upward, solenoid Q having become weakened, so that contact J makes contact with contact-piece-M. The springs t t" and u' u" are then bridged and contact across the springs t o is broken. Rheostat F and solenoids N and Q are now short-circuited and the armatures take current directly from the mains. Solenoids O, U, and V in multiple-shunt arrangement maintain their respective cores in a raised position, which they will continue to do until the controlling-switch D is broken. Upon contact-piece n passing out of contact with springs fu t" the current is shunted through the lamps y y, thus reducing the current in the multiple-shunt circuit. As before stated, switch D is not used in the ordinary operation of the elevator and is normally open. Should the motors be started from the switch D in the car, this switch being opened and closed in a manner hereinafter to be described, a circuit would be completed as follows: Starting from the positive lead at 1 the current will follow the same course bcfore described, passing through solenoid O to the point From thence the current continues by wire 6 to the end 7 of flexible cable 8, through the cable to the elevatorcar and contact CZ of switch D, through the switch, and back by wire 9 through cable 8 to the cable end 7, and still by wire 9 to the negative lead at post lO. The course of the armature and eld currents and the operation of the starting apparatus is then as before described when switch D was closed, and the motors attain normal speed, both running at the same number of revolutions per minute.

39 represents a brake-solenoid adapted to remove the brake from that part of the elevator apparatus to which it may be applied, while I is a switch in the car adapted to control the action of the brake. The startingswitch D and brake-switch I Vare so arranged that one may not be opened or closed without opening or closing the other, while since the circuit of the brake-solenoid includes the contactpiece t and springs t Z, through which circuit is not completed until the last core T is attracted upward and the motors have about attained normal speed, it follows that the brake cannot be removed until the motors have started and is also returned before the motors have stopped. The brakecircuit may be traced as follows: Leaving the positive lead at post l by wire 40, the current passes through spring t, contact t to springt", thence by wire 4l to solenoid 39, thence by wire 42 to the end 43 ot' cable 44, through the cable by wire 42 to contact z' of switch I on the car, and then returns by wire 45 through the cable to cable end 43 and to binding-post 46, tapping onto the eld at 47, and returning thence to the negative main.

In order that the switches D and I may be simultaneously operated, any suitable form of switch-lever may be used; but I prefer to use that form patented by me in United States Patent No. 655,336, lgranted August 7, 1900, for a Controller,7 which device serves the function also of allowing the switch-arms of D and I to be thrown only when the operating-lever is in a central or neutral position, as fully shown and described in that patent. I have therefore shown upon the car A a diagrammatic representation of this form of controller, the essential features only of which will be again described.

The controller comprises a lever a, pivoted at a', from which point extend arms a2, rigidly connected to the lever, to which arms are connected springs Z). These springs are also connected to the pivoted switcharms D2, upon which they exert a downward pull, causing them to bridge the contact-pieces d @Z2 and t 2, respectively, when a lug c is withdrawn from contact with the inner ends of the switch-arms. The pieces CZ' are insulated from the pieces (Z3, so that there may be no electrical connection between the switches D and I. The lug c is fastened upon the end of a vertically-sliding rod c, carried by the lever et', this rod being forced downward by a suitable spring e', fastened at e2 to the lever and at e3 to the rod. Upon the upper part of the rod is another lug c4, working in a slot a3 in the lever a, and behind the lever extends a grooved arc-shaped piece f, (which may be part of the frame of the controller,) with flanges f', having a central opening f2, in which lug e4 may enter when the lever a is opposite the center of the arc. Vhen lug c4 enters the opening f2, spring e forces rod e down and causes lug c to impinge upon the inner ends of switch-arms D2, forcing the arms out of contact with their respective contacts. By pulling the rod upward the arms D2 are released and close their respective switches. When lug e4 is removed from the openingf2, the lever ct may be moved to the right or left, lug c4 sliding upon the top of tiange f', and thus the lug c is prevented from actuating switch-arms D2 unless the lever a is in a central or neutral position. Con'- tact-pieces h and j on the back of lever Ct are adapted to sweep over contacts Zt Z m n o jp and a conducting-arc g, respectively, when the lever is moved to the right or left, the pieces h andj being electrically connected, preferably by fiat springs, in the manner described in my Patent No. 655,336, above referred to. Piece his adapted to make contact with the contacts Zr. Z m n 0 p separately, except as to the two central contacts m and p, with both of which it makes contact at the same time, and when the lever a is in a central or neutral position, for reasons which will hereinafter appear, the motors are both running at the same speed and the car is stationary. Vhen the lever is moved to the right or left, the speed of one or the other of the motors is varied,for the farther it is moved to the left over the contacts 7c Z m the greater number of coils are short-circuited in the fieldwindings of motor B, and hence B speeds up, while motor C remains at normal speed, and the farther the lever is moved to the right over contacts n o p the greater is the number of coils short-circuited in the field-windings of motor C, so that this motor speeds up, motor B in the meantime having been returned to normal speed. Therefore the mechanical connections may be so arranged that if motor B is running at the higher speed the car will move up, while if motor C is running at the higher speed it will move down. The electrical connections for carrying into effect this system of field control consist in this instance of parallel circuits connecting various coils of the motor field-windings with the contacts Zt' Z 'm n op on the car and a common conductor which connects a point on the field-circuit between the two motor-fields with the conducting-arc g in the car in order that one eld may be varied while the other is left normal. This common conductor is also connected to the contact-springs u' u, so that its circuit includes the contact-piece u on core T, and since this contact-piece u is normally out IOC) IIO

' cuited it will be evident that no variation can be eiected in the speed of either motor until this switch u is closed and the motors have attained normal speed, both running at the same number of revolutions per minute. In other Words, it is only through this common conductor that electrical connection can be made between the field-controller on the car and that field which is to be varied.

Any suitable connections may be used in carrying out my system of field-control, I having shown a method which is particularly applicable to motors whose armatures and fields are arranged in the relationship described; but Without departing from the spirit of my invention other methods may be devised applicable to this arrangement of motors and their fields or methods applicable to other arrangements ot' other types of motors. In the accompanying diagrams connections are made from the points 7a2 Z2 m2 on iield- .Winding IV by Wires 48 to insulated bindingposts 49, and thence through the cable 30 by wires 50, '50, and 501 to binding-posts 5l, and connections are made from the points 7c Z' m in field-winding `X by wires 52 also to the insulated posts 51. Posts 51 are connected by

wires

53, 53, and 531 through cable 8 to contacts 7c Z m on the car. Connections are like- Wise made from the points n2 o2 p2 on fieldwinding Z by wires 54 to the insulated binding-posts 55, and thence through cable 36 by wires 56 56a 561 to the insulated bindingposts 57, and connections are also made from the points p o 'n' on field-winding Y by Wires 58 to the insulated binding-posts 57. Posts 57 are connected Aby Wires 59 591 591 through cable 44 to contacts n op on the car.

The common conductor above referred to passes from contact-arc on the car at the point g by wire 60 through cable 44 to cable end 43 and from thence by wire 60 to contact-spring u and from contact-spring u" by Wire 6l to binding-post 3l on motor B, thus cutting in on the motor field-circuit at a point between the respective tields of the two motors.

It was hereinbefore stated that upon the closing of the armature-circuit part of the field-current followed a path in shunt to the held-circuit through the field-controller on the car. This is so only when the lever-arm a of the Held-controller is in its central or neutral position, so that both contacts m and 19 are bridged by contact-piece Zt. V'Vhile all of the coils in the field-windings of both motors are energized, at the same time part of thecurrent follows a shunt-circuit, starting from the point m2 on winding W and passing from thence by wire 48 to a post 49 through cable 30 -by wire 50 to a post 5l, and current also passes from the point m on winding X by a Wire 52 to post 5l, to which Wire 50 connects, and from thence there is a common path by wire 53 through cable 8 to contactm, through contact-piece Zt to contact p, back by wire 59 through cable 44 to a post 57, Where the current divides, part passing by a wire 58 and tapping the field-winding Y at p', while a part passes by wire 56 through cable 36 to a post 55 and by wire 54 to the point p2 on field- Winding Z. It will therefore be obvious that While the lever a of the field-controller is in its central or neutral position over contacts m and p the fields of the motors are equally energized, and they are consequently running at the same speed, and the car is standing still. Now let the lever a be moved to the left,so that contactpiece Zt rests upon contact Z only. Then the eld-circuit may be traced as follows: The energizing-current reaches the elds at post 26 by wire 25, and since the points Zzand Z on the fields W and X are electrically connected with contact'Z on the car that part of the field-coils respectively between the points Z2 and Z and binding-post 3l Will be shortcircuited, and the vcurrent will pass directly from thepoints Z and Z2 to contact Z. Starting from Z2 in field-winding WV, the current will pass by wire 4S to post 49, thence through cable 30 by wire 50a to post 5l, and current also passes from the point Z on field-winding X to binding-post 5l. From thence the current passes through cable S by wire 53a to contact Z, thence to arc g, thence by common conductor 60 through cable 44 to cable end 43 and continues by common conductor 60 to spring u', to spring u, by common conductor 61 to binding-post 31, thence by wire 33 to post 34, and from thence through the entire field-windings Y and Z back to the negative lead. The field magnetization of motor B has thus been reduced, while that of C has remained unaltered, and B will speed up, while vC will remain at normal speed. It

IOO

lever a is moved to the right, so that contactpiece h rests upon contact o, the field-current will pass through the entire field-windings of 9 `tor 60 to arc g on the car and contact o, thence lback through cable 44 by wire 59 to post 57,

where the current divides, part passing by Wire 58 to the point 0 on the held-winding Y, thus short-circuiting some of the'coils of this field, and part passing by wire 56a through cable 36 to post 55, thence by wire 54 to the point o2 on winding Z, thus short-circuiting some of the coils ot' this eld. Hence motor C will speed up and motor B remain at .normal speed.

In my system it has been shown that the controlling-lever a, on the car must be moved to a central position-in order to operate the starting and stopping switch D and that in this position the field magnetization ot' each motor is the same, a variation in the eld magnetization of either motor being possible only by a movement of the lever to one side IIO or the other of the center. It has also been shown that this variation can only be produced when the circuit through the common conductor is completed, which does not take place until the last core T is attracted upward and the motors are derivingl current directly from the mains. From the foregoing considerations it therefore follows that no variation in the relative speeds of the motors can be produced until they have reached their normal speed and are running at the same number of revolutions per minute, nor can they be stopped after the speed of one has been varied untiltheyhave been brought back to normal speed. It is at once obvious to those skilled in the art that this improved method of operation is of the utmost utility in a system such as I have described, since chances of injuring the motors are greatly reduced, certainty of operation is provided and smooth consistentworking obtained with the greatest economy.

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States, is-

l. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, and means for shortcircuiting the current through a portion of the field of either one of the motors, substantially as set forth.

2. The combination of two electric motors capable of running atthe same and also at relatively diiferent rates of speed, a car operated thereby, the same remaining stationary when the said motors run at the same speed and moving either upward or downward when said motors' run at relatively dilerent rates of speed, a source of electrical energy, and means carried by the car for cutting ont fieldsections of either motor while the strength of the field of the other lnotor remains unaltered, substantially as set forth.

3. The combination of two electric motors, a circuit therefor, a car operated by said motors in the manner described, a motor-starter, and controlling mechanism dependent forits operation upon the previous working of the motor-starter, substantially as set forth.

4. The combination of two electric motors, a car operated thereby as described, a source of electrical energy, and devices for starting said motors and controlling their respective speed, the arrangement being such that the motors will be fully started before their speed can be varied and their speed must again be equalized before they can be stopped, substantially as set forth.

5. The combination of a car, two motors adapted to operate said carin connection with a brake, a source of electrical energy, a starting apparatus and circuit therefor including a switch, and a circuit including a solenoid capable of withdrawing the brake and also including a switch in parallel with the switch of 'said starting apparatus, said switches being worked together and operating to make and break circuit so that the brake will be withdrawn only after the motors are started and will be again applied before they are stopped, substantially as set forth.

6. The combination of two motors, a source of electrical energy, a car operated by said motors in the manner described, in connection with the brake, a circuit including a switch and means for withdrawing the brake, and a controller occupying a neutral position at the time when said switch is being closed or opened, substantially as set forth.

7. The combination of two motors, a source ot' electrical energy, a car operated by said motors as described, in connection with a brake, a stai-ting apparatus, a circuit for the starting apparatus and for the brake, means for electrically removing the brake, and a controller occupying a neutral position at the time of the closing and opening of the circuit, substantially as set forth.

8. An elevator system comprising two electric motors having their fields connected in multiple severally and` in series collectively, their armatures being also connected in multiple, a car operated by said motors in the manner described, in connection with asuitable brake, a motor-starter, means for electrically withdrawing the brake after the inotors are started, a controller workable subsequently to the starting of the motors and withdrawal of the brake, a source of electrical energy, and circuits for the motor-armatures, fields, starter, brake, and controller, the circuit of the motor-starter including lamps and a. differential solenoid with a core carrying contact-disks respectively adapted to cnt in the lamps and close the field and brake circuits, substantially as set forth.

9. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, and electrical means for varying the speed of either motor, substantially as set forth.

10. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, and means for varying the field magnetization of either motor, substantially as set forth.

1l. The combination of a car, two electric motors connected therewith in such a Way that when they are both running at the same speed the carwill remain stationary and when they are running at relatively different rates IOO IZO

of speed the car will move either upward or downward, a source of electrical energy, and electrical means controlled from the car'for varying the speed of either motor, substantially as set forth.

12. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationaryand when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, and means controlled from the car for varying the field magnetization of either motor, substantially as set forth.

13. The combination of a car, two electric motors connected therewith in such a way that when they are both` running at'the same speed the car will remain stationary and when they are running at relativelydifferent rates of speed the car will move either upward or downward, a source of electrical-energy, and means controlled from the car for short-circuiting the current through a portion of Athe field of either one of the motors, substantially as set forth.

14. The combination of a car, two electric motors connected therewith in such a way that when they are bth running at the same speed the car will remain stationary a-nd when they are running at relatively different rates of speed the/car will move either upward or downward, a source of electrical energy, and electrical means for varying the speed of either motor, while that of the other is maintained constant, substantially as set forth.

15. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at Yrelatively different rates of speed the car will move either upward or downward, a source of electrical energy, and means for varying the field magnetization of either motor while that of the other is maintained const-ant, substantially as set forth.

'16. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, and electrical means controlled from the car for varying the speed of either motor while that of the other is maintained constant, substantially as set forth.

17. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationaryand when they arerunning at relatively different rates of speed the car will move either upward, or downward, a source of electrical energy, and means controlled from the car for varying the field magnetization of either motor while that 18. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same spee'd the car will remain stationary and when they arerunning at relatively dierent rates of speed the car will move either upward or downward, a source of electrical energy, and controlling means, operative only after the motors have attained substantially normal speed, for varying the speed of either motor, substantially as set forth.

19. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are runninglat relatively dierent rates of speed the car will move either upward or downward, a source of electrical energy, and means, operative only after the motors have attained substantially normal speed, for varying the field magnetization of either motor, substantially as set forth.

20. The combination of a car, two electric motors connected therewith in such a way that when they are both running at' the same speed the car will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, and controlling means, operative only after the motors have attained substantially normal speed,forshort-circuiting the current through a portion of the field of either motor, substantially as set forth.

2l. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, and controlling means controlled from the car, operative only after the motors have attained substantially normal speed, for varying the speed of either motor, substantially as set forth.

22. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, and means controlled from the car, operative only after the motors have attained substantially normal speed, for Varying the field magnetization of either motor, substantially as set forth.

. 23. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at relatively dierent rates of speed the car will move either upward or IOO IIO

downward, a source of electrical energy, and controlling means controlled from the car, operative only after the motors have attained substantially normal speed for short-circuiting the current through a portion of the field of either motor, substantially as set forth.

24. The combination of a car, two electric motors connected therewith in such a way vthat when they are both ruiming at the same speed the car will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, and controlling means, operative only after the motors have attained substantially normal speed, for varying the speed of either motor while that of the other is maintained constant, substantially as set forth,

25. The combination of a car, two electric motorsconnected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, and means, operative only after the motors have attained substantially normal speed, for varying the field magnetization of either motor while that of the other is maintained constant, substantially as set forth.

26. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, and controlling means, operative only after the motors have attained substantially normal speed,forshort-circuiting the current through a portion of the field of either motor while that of the other is maintained constant, substantially as set forth.

27. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, and controlling means controlled from the car, operative only after the motors have attained substantially normal speed, for varying the speed of either motor while that of the other is maintained constant, substantially as set forth.

28. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationaryand when they are running at relatively differentiates of speed the car will move either upward or downward, a source of electrical energy, and means controlled from the car, operative only after the motors have attained substantially normal speed, for varying the field magnetization of either motor while that of the other is maintained constant, substantially as set forth.

29. The combination of a car, two electric motors connected therewith in such a way that when they are both runnning at the same speed the car will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, and controlling means controlled from the car, operative only after the motors have attained substantially normal speed for short-circuiting the current through a portion of the field of either motor while that of the other is maintained constant, substantially asset forth.

30. The combination of a car, two electric motors connected therewith in such a Way that when they are both'running at the same speed the car will remain stationary' and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, means for starting and stopping the motors, and means for varying the speed of either motor, the arrangement being such that the motors must be brought to run at normal speed before they can be stopped, substantially as set forth.

3l. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, means for starting and stopping the motors, and means for varying the eld magnetization of either motor, the arrangement being such that the motors must be brought to run at normal speed before they can be stopped, substantially as set forth.

32. The combination of a car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at relatively dierent rates of speed the car will move either upward or downward, a source of electrical energy, means for starting and stopping the motors, and means for short-circuiting the current through a portion of the field of either motor, the arrangement being such that the motors must be brought to run at normal speed before they can be stopped, substantially as set forth.

33. The combination of the car, two electric motors connected therewith in such a way that when they are both ruiming at the same speed the car will remain stationary and when they are ruiming at relatively different rates of speed the carwill move either upward or downward, a source of electrical energy, means for start-ing and stopping the motors, and electrical means for varying the speed of either motor while that of the other is maintained constant, the arrangement be- IOO IIO

that when they are both running at the same speed the car'will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, means for starting and stopping the motors, and means for Varying the field magnetization of either motor While that of the other is maintained constant, the arrangement being such that the .motors must be lbrought to run at normal speed before they can be stopped, substantially as set forth.

35. The combination of the car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at relatively different rates of speed Jtuhe car will move either upward or downward, a source of electrical energy, means for start-ing and stopping the motors, and means for short-circuiting the current through a portion of the field of either motor while that of the other is maintained constant, the arrangement being such that the motors must be brought to run at normal speed before they can 4be stopped, substantially as set forth.

36. The combination of the car, two electric motors connected therewith in such a way that when theyare both running at the same speed the car will remain stationary and` when they are running at relatively different rates of speed the car will move either up-` ward or downward, a source of electrical en-` ergy, means for starting and stopping the motors, and electrical means, operative only after the motors have obtained substantially` normal speed, for varying the speed of either' motor, the arrangement being such that the motors must again be brought to run at normal speed before they can be stopped, substantially as set forth.

37. The combination of the car, two electric motors connected therewith in such a way that when they are bot-h running at the same speed the car will remain stationary and when they are running at relatively dierent rates of speed the car will Vmove either upward or downward, a source of electrical energy, means for starting and stopping the motors, and means, operative only after the motors have attained substantially normal speed, for varying the eld magnetization of either motor, the arrangement being such that the motors must again be brought to run at normal speed before they can be stopped, substantially as set forth.

38. The combination of the car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and lwhen they are running at relatively different 39. The combination of the car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationaryv and when they are running atrelatively different rates of speed 4the car will move either upward or downward, a source of electrical energy, means for starting and stopping the car, and controlling means,'operative only after the motors have attained substantially norF mal speed, for varyingthe speed ofv either motor while that of the other is maintained constant, the arrangement being such that the motors must again be brought to run at normal speed before they can be stopped, substantially as set forth.

40. The combination of the car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are runningat relatively different rates of speed the car will move either upward or downward, a source of electrical energy, means for starting and stopping the motors, and means, operative only after the motors have attained substantially normal speed, for varying the field magnetization of either motor while that of the other is maintained constant, the arrangement being such that the motors must again be brought to run at normal speed before they can be stopped, substantially as set forth.

4l. The combination of the car, two electric motors connected therewith in such a way that when they are both running at the same speed the car will remain stationary and when they are running at relatively different rates of speed the car will move either upward or downward, a source of electrical energy, means for starting and stopping the motors, and controlling means, operative only after the motors have attained substantially normal speed, for short-circuiting the current through a portion of the field of either motor while that of the other is maintained constant, the arrangement being such that the motors must again be brought to run at normal speed before they can be stopped, substantially as set forth.' y

In testimony whereof I hereunto set my hand in the presence of two witnesses.

ETHELBERT M. FRASER. [n s] Witnesses:

L. C. FRASER, A. II. STE..MARIE.

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