US595874A - Electric elevator - Google Patents

Description

(No Model.) 6 Sheets-8heet 1'.

A. L. DUWELIUS.

ELEOTRIG ELEVATOR.

N0 595.874 Patented Dec. 21,1897.

6 SheetsSheet 2.

(No Model.)

A.- L. DUWELIUS.

ELECTRIC ELEVATOR.

Patented Dec. 21,1897.

(No Model.)- 6 Sh e etsSh eet 3.

- A. L. DUWELIUS.

ELECTRIC ELEVATOR. No. 595,874. Patented Dem-21, 1897.

(No Model.) 6 S116tS-Sh66t 4.v A L. DUWELIUSi ELEGTRIG ELEVATOR PatentedDeo. 21, 1897.

(No ModelL) v 6 Sheets-Sheet 5.

A. L. DUWELI-US, ELECTRIC ELEVATOR. No. 595,874. Patented Dec. 21,1897.

T ucnms PETERS my. PHDTOUTHO..WA5NINGTON a c UNirn STATES ATENT FFICE.

AUGUSTUS L. DUWELIUS, OF CINCINNATI, OHIO.

ELECTRIC ELEVATO R.

SPECIFICATION forming part of Letters Patent No. 595,874, dated December 21, 1897. Application filed February 18, 1892. Serial No. 421,925. (No model.)

maintain the movement when once started.

This law has special significance in connection with motors of electrically-driven elevators. With other kinds of motive power overloading only prevents the starting of the engine, while with the ordinaryelectric motor the effect is to burn it out and disable it. A like effect is produced by the accidental stoppage of the elevator by obstructions in the hatchway or otherwise. To prevent awaste of current the motor should be energized in starting before the brake is released and disconnected from the line-circuit in stopping before the brake is applied. This necessitates the construction of a switch or controlling apparatus which has the abnormal function of being first on and first off with rela tion to the brake. The frequent use of the switch incident to elevator service also requires special construction to prevent deleterious arcing and sparking. When a comparatively high speed is attained, the difficulties of stopping readily and smoothly-that is, without jar or shock-and accurately with .the landings increases with the speed. In electric elevators as generally constructed counter-shaftin g or spur, worm, or other gearing is interposed between the motor and the hoisting-cable, involving complication of parts loss of power, limitation of speed, and lack of smoothness in operation, due to thejarring of gears.

The type of electric motor in use for elevator purposes requires in starting the manipulation of a switch to energize the field-magnet and of a rheostat to allow the rotation of the armature to generate sufficient counter electromotive force to prevent an excessive influx of current, and the consequent undue heating of the conductors, destruction of the insulation, and disabling of the motor. The manipulation of the rheostat requires care,

skill, and judgment upon the part of the operator, and any failure in either of these is likely to result disastrously. In attempts to use the ordinary electric motor in a service to which it is not adapted it has been the practice to allow the motor to run continuously, or to maintain a current through the field-magnet coils constantly during business hours, or to start the motor by the use of a switch and rheostat and then start the elevator. In stopping, the manipulation is in the reverse order, leaving the current on until after the cab has stopped and involving an element of uncertainty as to the cutting off of the current. These methods entail a waste of electric current and loss of time and interfere with the practical operation of the elevator. To protect the motors employed in this service recourse is had to the insertion in the line-circuit of a section of fusible wire, the duplication of which is a matter of extreme uncertainty, as it is necessarily destroyed in testing, and it does not furnish the absolute protection required. When by chance of .the proper size to protect the motor, its fusing requires the substitution of another, the ole-- vator in the meantime being disabled. To avoid the inconvenience and annoyance of frequent substitution of fuses the tendency is to use large fuses, the result of which is that it has become an aphorism that a fuseprotected motor eventually burns out in this service.

One portion of my invention relates more specifically to the type of elevators known as sheave-driven, in which the poweriis transmitted to the hoisting-cable through its ongagement with a portion of the periphery-of a driving-sheave as distinguished from the drum-driven elevator, in which the hoistingrope is attached to or wound about the periphery of a winding-drum. Among the inherent advantages of the former over the latter type may be mentioned the impossibility of unwinding the hoisting-rope faster than the car descends and the avoidance of all danger of overrunning into the upper works. This is due to the fact that when either the car or the counterweight encounter obstacles in their descent or reach the bottom of the hatchway the engagement between the sheave and hoisting-rope is lessened sufiiciently to As thehoisting-rope 5 of the elevator-car merely involves an in- 1 crease in the length of the hoisting-rope,

while with thed'ru-m-driven elevator serious practical difliculties are encountered in attempts to provide drums of sufficient capacity to wind and stow the long ropes incident to elevators of great range of travel.

This 1 is due to thepeculia'r conditions surrounding 1 elevator hatchways.

Owing to the natureof the service required of elevatorropes they are composed of wires madeof the-softest iron obtainable and frequentlyaunea-led during the process of drawing to insure plialoility.

'To secure the degree'of engagement between the driving sheave and hoisting-rope neeessarytotransmit the power to the elevator-car, ithas been the practicetoprovide the driving-sheaves with grooves having two sidesat anacute angle and resembling the letter V The *wedgingof the hoisting-rope in the "groove, if sufficiently acute, insured the transmissionnf *the'mdtive power. The

rope employed was to pinch it out of shape, causingachange in themolecularstructure df thetvirsjollcwecl bythe frictional weartojthe outside'of thelrope incident to its-repeated wedgi'ng in and release from the groove and its finaldestruction within so sliortaservice a'sto render itsemployment in this manner both "unprofitable anddangerous. This was due to the pinchin thevgroove and the pressure resulting from the combined weight of theca'r with its load-and the counterweight. Attempts todispeusewith thev-grooves'and the consequent wedging and pinching of the rope by substituting elastic fillings in non-- wedging grooves were rendered prohibitive bythe great strainon the hoisting-rope di- 1-ectly*si1staining the weight of its-fear and counterweight. 'ln order to obviatetIie premature tles'tructiono'f the rope and to render tliistitherwise desirable method of transmission practically ancr commercially successful, I'e'mployan-arrangement of the hoisting-rope by'whic'lrthe press ure of eli gage ment' between it and the driving sheave *and the tensile *strain of and power transmitted "to therope at this peintrepresentbut 'a fractionof "the combined weight of the car and counter weight, this fraction beingcapable of regulation to'keep the pressure strains and power transmission at the point of enga ement u ith the" sheave Withiirpractical workinglimitsto insure greatest longevity of the rope, the engagement being frictional as distinguished from gripping.

- The object of my invention is to provide means for obtaining higher speed and higher speed relatively to the motive power, means for producing a comparatively powerful "torque or pull to overcome the inertia incident to starting an elevator, means for auto matically regulating and limiting the quantity of current received by the motor to protect it from burning out and thereby reducing the possibility of error on the part of the operator to the minimum, means for electrically arresting the movement of the elevator without jar or shock, means for electrically regulating the speed of an elevator moved bygr'aivity without the'consumption of linecurrent, means for 'brealiing the electric circuit to protect the 'motor in the event of accident to the regulatingand limiting device, means for reconnecting the circuit by the mani ulation of the shifting cable, and to provi 'e mechanism whereby the lifting capacity of thee'leva'tor m'ay beilicreased Without increasing the strain or "wear upon the cableor hearings or increasing the'trave'l'of the'cou'nterweight. These objects I can accomplish partly by supplying novel instrumentalities adapted 'to perform specific functions a'nd pa'rtly bythe combination and arrangement ofthe coactin' g parts; and'theinvention consists in theinstrumentalities and combination andarran 'ement of instrumentalities hereinafterdescribed-and claimed.

Inthedrawings, Figure l is a front 'view showing an elevator-'hatchway, the cage or ca b,'anelecti-i'c motoig'and. the connections between the motor'andthe cab; Fig-'2, adiagram'matic view illustrating the power-multiplying mechanism; Fig.3,atopview of the field-coil -section short-circuiting terminals; Fig.4,a'side view of the governor employed for regulating the strengthof field; Fig.5,"a view ofthesame at right angles to'the positidnehownin Fig/4; Fig. 6, a front View of apreterred form of circuit-breaking mechanism; Fig.7, a front view ofa'switch orcommhtator; Fig. 8, a side view of the same; Fig.9,"a diagrammatic view showing the terinitials and connections of a series motor adapted to heconvertedinto a series dynamo oirelosedcirctiit; Fig. 10, apla'n view ofthe switc h-lcontact terminals. Fig. 11 illustrates the positions of the'switch for starting, reveising, *andstopping the elevator. )Fig. 1-2 is a diagrammatic view illustrating theelectrical connections; Fig. 13, a perspective View showing the relative positions of the brake and'sWitch.

representsthe hatchway of an elevator; 13, the cage, platform, or car,hereinafter called the cab, and C an electric motor having a shaftc,'upo1'1whiehisa sheave orother powertransmitting device 0.

D is a cable the ends of which are repre-- sented as fastened to the superstructure at'a and a.

E is a counterweight provided with a sheave e, adapted to travel upon the cable. The cable in the arrangement shown in Fig. 1 takes under asheave 1) upon the elevator-cab, over a sheave or sheaves a on the superstructure, under the sheave c on the motor-shaft, over a sheave or sheaves a on the superstructure, under the sheave e, which carries the counterweight, and thence to its point of attachment.

It will be observed that with the connections illustrated in Fig. 1 the motor has a leverage of two to one in its favor. In Fig. 2 I have illustrated the method of making the connections so applied as to give the motor a leverage of four to one. In this instance the cable takes under a sheave b on the cab, over a sheave a on the superstructure, under another sheave b on the cab, over sheave a under the sheave c on the elevator-shaft, over a sheave a again under the sheave 0', over a sheave or sheaves a under the sheave e on the counterweight, over a sheave a on the superstructure, under another sheave e on the counterweight, and thence to its point of attachment. It will be seen that the counterweight and cab are rigged alike with reference to the cable. By following the same general plan the leverage of the motor may be increased to any required extent.

' While I have illustrated the hoisting-cable with fixed points of attachment, this is by no means essential, as the same result may be obtained in other ways. In either case the ends of the cable should be at the points where the rate of its travel is the slowest. This plan of construction permits a direct engagement of the hoisting-cable with the drum or drums on the motor-shaft, eliminates the usual interposed gearing and jarring incident thereto, avoids the great waste of power due to the gearing, and permits the accommodation of the speed and torque of the motor to the required speed and power of the elevator. Instead of an auxiliary or separately-constructed rheostat or starting-box or supplementary or additional field-coils I provide the field-coils with sectional or short-circuitin gterminals c brought preferably to the top of the motor.

F is a governor consisting of a shaft f, adapted to rotate with the armature and carrying sector-shaped weights f, illustrated as centrally pivoted, the opposite ends being of quadrant form. These weights are pivoted, preferably, to a carrier f (which may be in- Legral with the shaft) in such manner that they are free to be moved by centrifugal force from their position of rest until their centers of mass meet at a line through their pivotal points and at right angles to the shaft. The motion of the weights is transmitted through the medium of links f to an equalizer f mounted upon an end-thrustf guided in carrier f". The end-thrust impinges upon and actuates a lever G, fulcrumed at g. The weights, may be returned to their position of rest by springs f or their equivalent. By this means I secure a relatively heavy or lowspeed governor, which is prompt to act at low speeds, without developing excessive power at high speeds, as distinguished from the ordinary centrifugal governor,which is designed to perform its functions when attaining an excessive speed.

To one end of lever G is attached a stem 9, carrying at its free end contact-plates g adapted to engage with the short-circuiting terminals ofthe field-coil section. When the elevator is at rest, the stem occupies such a position as to leave the contact-plates 9 out of engagement with the short-circuiting terminals 0 in which it is preferably held by a spring The governor is arranged to be actuated by the rotation of the armature of the motor, and when actuated forces the lever G and stem g outwardly. This movement brings the contact-plates g into engagement successively with the terminals 0 of each of the field-coil sections, thereby shortcircuitin g them and weakening the field. The action of the governor continues to force the stem 9 outward until the normal maximum speed of the motor is attained, the contactplates being so placed that when this speed is attained anypredetermined number of fieldcoil sections will be short-circuited. If for any reason the motor should attain a speed greater than the predetermined maximum,the action of the governor through'the lever and the stem draws the contact-plates still farther, thereby successively breaking the connection between the sh ort-circuiting terminals and increasing the strength of the field and conse quently the counter electromotive force and reducing the speed of the motor.' The purpose and effect of this construction is to decrease the strength of the field in the direct ratio of the generationof counter electromotive force in the motor and to utilize for power purposes the current ordinarily wasted in the resistance-coils.

. H, Figs. 7 and 8, is an electric commutator or switch consisting of a series of plates h, preferably in the form of sectors, arranged in parallel planes and constituting electric contact-terminals.

I is a rocker shaft connected with and adapted to be actuated by the shifting cable or its equivalent. Upon the rock-shaft, but separated therefrom by a fixed insulatingbushing h, is a carrier 72;, so mounted as to be capable of partial rotation upon the bushing. This carrier is preferably mounted in such manner that it may be clamped to its bushing with a greater or less degree of pressure. In the form shown it is divided longitudinally to form a split hearing, which is made adjustable by a bolt h The pressure is rendered by an interposed spring 71 In one end of the carrier is mounted an insulated rockingbeam hihereinafter called the working beam, provided at its ends with a series of contact-closers h, adapted to make and break electrical connection between the various contact-terminals h.

Secured to and actuated by the rockershaft I is a crank-arm h adapted to engage with and actuate a crank arm h secured to the trunnion of the working beam. In the crank-arm 77. is a slot h", taking over a pin h projecting from the carrier 77?. It will be seen that with the parts in the position shown in Fig. 7 the initial movement of the controllingcable, acting through shaft I, will move the crank-arm 71 thereby moving crank-arm h and working beam 7L5. Movement of the Working beam in either direction brings one series of the contact-closers hiinto engagement with certain of the contact-terminals, thereby making predetermined electrical connections. During this initial movement the carrier, being clamped to the bushing h with sufficient pressure to hold it against rotation until positively driven by engagement with the wall of slot h, remains stationary. After the pin h engages with the wall of slot 71. the motion of the shaft I is imparted through crank-arm 71, and pin 71 to the carrier, the combination of electrical contacts made by the initial movement being maintained. This permits the shifting cable to perform subsequent work, such as manipulation of the elevator-brake. The brake may be of any approved type; but I have shown a brake con-.

sisting of a friction-wheel 0 secured to the armature-shaft, a strap c taking over the friction-wheel and secured to a lever carrying a weight 0. Extending from the lever is a pin 0 adapted to ride on a cam t" on the rock-shaft. In the position shown the motor is serving as a dynamo, having just been disconnected from the line-circuit, and to apply the brake the rotation of the rock-shaft I must be continued in the direction indicated by the arrow until pin 0 drops into a recess 1' in the cam 'i; The weight 0 then depresses the lever 0 and holds the strap 0 in contact with the friction-wheel 0 The reverse movement of the shaft I firstbreaks the existing electrical connections, then brings the other series of contact-closers into electrical connection with another set of contactterminals, and afterward performs the required mechanical functions. In other words, the movement of the shifting cable in either direction first efiects the necessary electrical combinations and then performs the neces sary mechanical functions.

Fig. 9 illustrates in diagrammatic form the terminals and connections of the motor, the terminals being numbered from 1 to 8. Fig.

' 10 shows the switch-contact terminals in plan,

the dotted lines representing possible switch connections. Fig. 11 shows in diagrammatic form the four positions of the switch serving in this arrangement to start, stop, reverse, and stop the elevator. Fig. 12 illustrates in diagrammatic form the electrical connections. In these figures, Lrepresents the fieldcoils, and M a rheostat adjustable in the ordinary way and variable by the action of the shifting cable. This rheostat may be connected directly with shaft 1. The letters a, b, c, and (Z, opposite parts of Figs. 9, 10, 11, and 12, represent corresponding electrical conditions in the motor, switch-contacts, and position of switch. The terminals in Figs. 10 and 12 are numbered to correspond with those in Fig. 9. Of these figures, 1 and 2 denote the line-terminals, 3 and 4 the field-coil terminals, 5 and 6 the armature terminals, and 7 and 8 the terminals for making a short circuit, including the motor then serving as a dynamo. Condition a represents the elevator at rest, with the motor connected as a dynamo and disconnected from the supply=circuit. Condition 27 may be taken as representing the ascending movement of the elevator, the inotor being connected with the supply-circuit. Condition c represents the reverse movement of the elevator, the motor being still connected with the supply-circuit, but having its armature-terminals reversed with reference to condition 27. Condition 61 represents the stopping of the elevator, the supply-circuithaving been out out and the motor converted into a dynamo driven by the elevator on a closed circuit of greater or less resistance. To reascend, recourse is had by means of the switch to condition I), which corresponds with condition d, except that the armature terminals are reversed. When it is desired to have the preponderance of weight at all times in the elevator-cab and use electric power only for hoisting the cab, the conditions a, b, and 01 may be used, condition abeing used to regulate the descent by gravity of the cab, requiring it to perform work by driving the motor as a dynamo and causing it to generate current through a circuit closed on a greater or less resistance M, variable by the shifting mechanism.

J is an eccentric preferably on an extension of shaft I, adapted to be actuated by the shifting cable j, mounted over sheaves in such manner as to be operated from the cab and serving to limit the play of lever G, thereby preventing the action of the governor beyond a fixed limit and permitting its increase by the operator and enabling him to decrease the normal speed of the elevator.-

In Fig. 6 I have illustrated an electromagnetic circuit-breaker.

K represents a supporting-plate, a magnet, and 70' its armature. The armature carries a hooked contact-arm 70 adapted to engage with and normally hold against the stress of its springa spring-actuated contact-arm 70 One end of the magnet-coilwire terminates in a binding-post 70 for connection with the line-circuit, while the other end is fastened to a metallic frame k in electrical connection which is in turn connected with the bindingpost is for connection to the motor-circuit.

A spring or its equivalent is attached to the arm 10 and by means of a regulatingscrew 10 with the base of the apparatus. This spring serves to hold the hooked arm 70 against the pressure of the armature, and the degree of magnetic force required to actuate the armature and thereby disengage the arm 10 from arm 10 may be regulated by changing the tension of the spring. The effect of this arrangement is to protect the motor by automatically breaking the supply-circuit when the supply of current tending to actuate the magnet reaches the predetermined limit to be received by the motor and required to overcome the stress of the spring. For the purpose of reconnecting the arms k and 10 after the operating-switch has disconnected the motor from the supply-line I employ a rockshaft (preferably rock-shaft I) connected with the shifting cable and provided with a cam 2', adapted to engage with and actuate a cam is", which in turn actuates a pendulum-lever 70 having a roller 10 at its lower end adapted to engage with and actuate arm 10 against the stress of its spring, thereby restoring it to its normal position and reconnecting electrically the arms k and 10 The operation of the shifting cable will actuate the swinging lever whether the circuitbreaker is set or not, and the swinging lever is preferably so mounted as to cause a slight movement of the spring-pressed arm 10 upon its point of contact with arm k thereby keeping the contacts free from any substances which might tend to impair the electrical connections.

I claim- 1. The combination with a constant-potential line-circuit of a series motor, an electric switch adapted to disconnect the line-circuit and close an independent circuit including the armature in series with a field of variable magnetic strength, thereby converting the motor into a self-excited generator adapted to be driven by the movement of the elevator, substantially as and for the purpose set forth.

2. In an electric elevator, the combination with the motor, of an electric switch adapted to disconnect the motor from the line-circuit, and substitute connections which complete an independent circuit, including the armature in series with a field of variable magnetic strength controlled by the shifting cable or its equivalent, adapted to retard the movement of the elevator, substantially as and for the purpose set forth.

movement of the shifting cable and maintain the makes or breaks during the continued movement of the shifting cable, substantially as and for the purpose specified.

4. The combination in an electric elevator of a shifting cable, a connection between the cable and a switch adapted to make or break the required connections and a connection between the cable and the elevator-brake whereby the brake is applied after the electrical connections are broken or released after the electrical connections are made, substantially as and for the purpose specified.

5. The combination with an electric elevator of a rock-shaft adapted to be actuated by the shifting cable or its equivalent, a working beam intermediately connected with and adapted to be rocked by the rock-shaft, a

series of plates serving as electric contactterminals, and a series of contact-closers at crank-arm upon the rock-shaft, a second crank-arm extending from the working beam, a rocking connection between the crank-arms, a series of plates serving as contact-terminals for the electrical connections, a series of insulated contact-closers at each end of the working beam adapted to make or break electrical connections between two or more contact-terminals at the initial movement of the rock-shaft, and mechanism whereby the carrier engages with the crank-arm of the rockshaft after the initial movement, and is moved thereby, substantially as and for the purpose specified.

7. The combination with an electric elevator of a rock-shaft controlled by the shifting cable, or its equivalent, a carrier movably mounted on a stationary bearing, a working beam pivotally mounted on the carrier, a crank-arm upon the rock-shaft and a second crank-arm extending from the working beam, a rocking connection between the crank-arms, a series of plates serving as contact-terminals for the electrical connections, a series of insulated contact-closers at each end of the working beam adapted to make or break electrical connections between two or more contact-terminals at the initial movement of the rockshaft, mechanism whereby the carrier engages with the crank-arm of the rock-shaft after the initial movement and is moved thereby, and a connection between the shifting cable and the elevator-brake whereby the latter is actuated during the subsequent movement of the carrier, substantially as and for the purpose specified.

8. The combination with an electric elevator of a rock-shaft controlled by the shifting crank-arms, a series of plates serving as contact-terminals for the electrical connections,

a series of insulated contact-closers at each end of the working beam adapted to make or break electrical connections between two or more contact-terminals at the initial movement of the rock-shaft, mechanism whereby the carrier engages with the crank-arm of the rock-shaft after the initial movement and is moved thereby, and a connection between the shifting cable and the elevator-brake whereby the latter is actuated during the subsequent movement of the carrier, substantially as and until the armature-shaft has attained its norfor the purpose specified.

'9. The combination in an electric elevator of a rock-shaft controlled by the shifting cable, or its equivalent, a fixed insulating-b ushing surrounding the rock-shaft, a series of plates adapted to serve as electrical contactterminals mounted upon the bushing, 'a carrier movably mounted on the bushing, a working beam pivotally mounted on "the carrier, one or more electrical contactclosers at each end of the working beam, a connection between the rock-shaft and the working beam vhereby the latter may be rocked by the motion of the rock-shaft, thereby bringing one or more of the contact-closers into engagement with contact-terminals and the carrier during the rocking motion of the working beam, substantially as and for the purpose specified.

10. The combination in an electric jeleva'tor of a rock-shaft controlled by the shifting cab'le, 'or its equivalent, a fixed insulating-bushing surrounding the rock-shaft, series of sector-formed plates adapted to serve as electrical contact-terminals mounted upon the bushing, a carrier movably mounted on the bushing, a working beam pivotall'y mounted on the carrier, one or moreelectrical contactclosers at each end of the working beam, a 1

connection between the rock-shaftand the working beam whereby the latter may be rocked by the motion of the rock-shaft thereby bringing one'or more of the'contact-cl'osers into engagement with contact-terminals and the carrier during the rocking motion of the working beam, substantially as and for the purpose specified.

11. The combination with 'the'shifting ca bl'eof the rock'shaft I; the insulating-bushing it, the plates h carried thereby, the carrier 7L2 movably mounted on the bushing, the Working beam h pivotally mounted on the carrier and carrying 'contactclos'e'rs 72 the crank-arm 721711110X! the rock-shaft, the crankarm h upon the working beam, the slot 71 and pin h ,substantially as and for the purpose specified. y

12. In an electric elevator the combination of a motor, its field-coils provided with sectional short-circuiting terminals, a centrifugal governor actuated by the rotation of the armature-shaftand adapted to electrically connect the sectional short-circuiting terminals of the field-coils before and until the armature-shaft shall have attained its normal speed, and to electrically disconnect the same when the armature-shaft exceeds its normal speed, substantially as and for the purpose set forth.

13. In an electric elevator the combination of a motor having its field-coils provided with short-circuiting terminals, a governoractuated by the rotation of the armature-shaft, a lever actuatedby the governor, and contactplates actuated by the lever and adapted to electrically connect the sectional short-circuiti'ng terminals of the field-coils before and mal speed, and to electricallydisconnect the same when the armature shaft exceeds the normal speed, substantially as and for the purpose set forth.

14:. A field-magnet governor for electric elevators consisting of a shaft, acarrier mounted thereon, 'weigh'tsof sector form pivoted to the carrier, an end-thrust guided by the carrier, an equalizer thereon and a connection between the equalizer and each of the weights, substantially as and for the purpose specified.

15. A iield magnet governorfor electric'elevatoi-s consisting of a shaft, a carrier mounted thereon, weights of double-sector form pivoted to the carrier, an end-thrust guided by the carrier, an equalizer thereon and a connection between the equalizer and each of the weights, substantially as and for the purpose specified.

16. Inan electric elevator, the field-magnet governor F, consisting of shaft f the weights f pivotally mounted thereon, the end-thrust f theeq'ualizerf ,thelinksf and the springs f, or their eqnivalent,combined and arranged substantially as and for the purpose specified.

IlO

1 7. In an electric elevator, the combination with line-circuit terminals, of an electric motor fo'r driving the elevator cab or cage, said motor having its field-coils and armature-coils in series with each other, an adjustable rheostat, and circuit-controlling devices operable from the elevator-cage and adapted to connect the field-coils and armature-coils in series with each other and to the line-circuit term-inals and to cut out the rheostat, or to disconmeet the field-coils and armature-coils 'from the line-circuit terminals and include said field-coils and armature-coils in series with each other and the rheos'tat in an independent circuit; substantially as and for the .purpose set forth.

18. In an electric elevator, the combination with line-circuit terminals, of-an electric motor for driving the elevator cab or cage, said a motor having terminals for its field-coils, and separate terminals for its armature-coilaan ad ustable rheo'stat and circuitcontrolling devices operable from the elevator-cage and adapted to connect the field-coils and armature-coils in series with each other to the linecircuit terminals, and cut out' the rheostat, or to disconnect the field-coils and armature coils from the line-circuit terminals, reverse the direction of current-flow in the armaturecoils and include said field-coils and armature-coils in series with each other and with the adjustable rheostat in an independent circuit; substantially as and for the purpose set forth.

19. In an electric elevator, the combination with a series motor, of substantially non-retarding multiplying-rigging connecting said motor to the elevator-cab, whereby the load imposed upon the motor during ascent is substantially that of the cab and its contents only, and an electric switch adapted to disconnect the line-circuit and close an independent circuit including the armature in series with a field of variable magnetic strength, whereby the necessary retardation for the cab on its descent is furnished by converting the motor into a self-excited generator adapted to be driven by the descent of the elevator substantially as and for the purpose set forth.

20. The combination with an electric elevator-cab, of an electric motor therefor, and nonretarding'rigging between the cab and electric motor, said rigging being operated directly from the latter; substantially as and for the purpose set forth.

21. The combination in an electric elevator of an electric motor,an electric switch adapted to break the line-circuit and close a circuit, including the motor, thereby converting the motor into a dynamo, adapted to be driven by the movement of the elevator, with rigging adapted to multiply the power, substantially as and for the purpose set forth.

22. The combination in an electric elevator of an electric motor, an electric switch adapted to break the line-circuit and close a circuit, including the motor, thereby converting the motor into a dynamo, adapted to be driven by the movement of the elevator, with a hoisting-cable and a counterweight carried thereby, and arranged to travel relatively thereto, substantially as and for the purpose set forth.

23. The combination in an electric elevator of an electric motor, an electric switch adapted to break the line-circuit and close a circuit, including the motor, thereby converting the motor into a dynamo, adapted to be driven by the movement of the elevator with a hoistingcable engaging with a sheave or other powertransmitting device on the motor-shaft, and taking under a sheave on the cab, and a counterweight carried by the cable and traveling relatively thereto, substantially as specified.

24. The combination in an electric elevator of an electric motor, an electric switch adapted to break the line-circuit and close a circuit, including the motor, thereby converting the motor into a dynamo, adapted to be driven by the movement of the elevator, with a motor- -to break the line-circuit and close a circuit,

including the motor, thereby converting the motor into a dynamo, adapted to be driven by the movement of the elevator, with a sheave or other power-transmitting device, two or more sheaves on the cab, a counterweight provided with two or more sheaves and a hoistin g-cable arranged to engage the transmitting device on the motor-shaft and to engage the sheaves on the cab and counterweight, substantially as and for the purpose specified.

26. The combination with an electric elevator of an electromagnetic circuit breaker adapted to break the line-circuit when the supply of current exceeds the predetermined limit, a swinging lever adapted to reset the switch, a rock-shaft adapted to be actuated by the shifting cable or its equivalent, and a cam upon the rock-shaft adapted to actuate the swinging lever, substantially as and for the purpose specified.

27. The combination with an electric elevator of an electromagnetic circuit-breaker consisting of a magnet in electrical connection with the line-circuit, a contact-arm carried by the armature of the magnet, a second contactarin electrically connected with the line-circuit and normally in contact with the arm carried by the armature, but adapted to be disengaged by the movement of the armature, a swinging lever adapted to engage with the second arm and restore it to its normal position, a rock-shaft adapted to be actuated by the shifting cable or its equivalent, and a cam on the rock shaft adapted to actuate the swinging lever, substantially as and for the purpose specified.

28. The combination with an electric eleva tor of an electromagnetic circuit-breaker consisting of a magnet in electrical connection with the line-circuit, a contact-arm carried by the armature of the magnet, a second contactarm electrically connected with the line-circuit and normallyin contact with the arm carried by the armature, but adapted to be disengaged by the movement of the armature, a swinging lever adapted to engage with the second arm and restore it to its normal position, a rock-shaft adapted to be actuated by the shifting cable or its equivalent, a cam on the rock-shaft, and a cam actuated thereby adapted to actuate the swinging lever, substantially as and for the purpose specified.

AUGUSTUS L. DUWELIUS.

WVitnesses JAMES N. RAMSEY, O. W. FIGNER.

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