US833968A

US833968A - Alternating-current controller.

Info

Publication number: US833968A
Application number: US28042405A
Authority: US
Inventors: David Larson
Original assignee: Individual
Current assignee: Individual
Priority date: 1905-09-28
Filing date: 1905-09-28
Publication date: 1906-10-23
Anticipated expiration: 1923-10-23

Description

PAIRNTRL OCT. 23, 1966. v D; LARSON. ALTBRNATING CURRENT CONTROLLER.

APPLIOATION FILED SEPT. 28, 1906.

2 SHEETS-SHEET 1.

. 0% 9% Ram INVENTOR A TTORIVEY PATENTED OCT. 23, 1906.

D. LARSON. ALTERNATING CURRENT CONTROLLER.

APPLICATION FILED SEPT.28,1905.

2 SHEETS-SHEET 2.

INVENTOE AQWJW BY ATTORNEY WITNESSES; 6f

' thence by con uctors 26 27 28. to other appa- UNITED STATES PATENT OFFICE.

DAVIDLARSON, F YoNKERsN-EW YORKQ 'AETERNATING-OURRENT coNTRoLL r-i.

' Specification of Letters-Patent.

Patented Oct. 23,190

Ap lication filed se amba 28. 1905., {serial No. 280,424.

To all whom itmwycuncern;

Beitknown that I, DAVID LARSON, 8. S11b- I .ject of the King of Sweden, and aresident of the city of Yonkers, in the county of W estchester-and; State of New York, have invented certain new. and useful 1m rovements in AL.

' -ter'nating-Current Control ers, of which the following is a specification.

' My 'nvention relates to electrical controllers for use in conjunction wlth alternating, intermittent, or pulsatingf currents; and it consists in the construction and arrangement of parts herein shown and described, the novel features whereof are pointed-out in claims. f

J Referringto the drawin s, Figurel is adia- --grammatic view .of'an e ectric motor and other apparatus and various electrical connections, whichtaken together. illustrate my invention. modification of the invention. ",Fig, 3 is another modification showing theinvention as ap lied to single-phase circuits. 1

I ike characters of; reference designate co rresponding parts in all of the figures.

1 0 designates an alternating-current motor. 20, 21, and 22 designate mains from a suit-: able source of electrical supply which may pass through a transformer 23, fuses 24, and

a manually-o erated main. switch 25 and rat'usnvhich will be described hereinafter.

designate the magnets of an elee-. trically-actuated reversing-switch S for start-* ing the moto'iiin either direction. The magnet 30 comprises a frame 31, preferably of laminated ma etic material, a core 32 or armature-of similar material, an excitingcoil 33,',three stationary contacts 34 35 36, and three movablejcontacts 37 38 39, which i are mounted upon but insulated-from across-1 which is adapted to connect a stationary segmental contact with any one of a'series of.

arm 51, conductor 53, magnet-win Fig. 2 is a similar viewshowinga- '50 is a manually-operated master-switch,

Before proceeding with the description of stationary contacts 56,"which. are connected I 'together' through resistances 57.

the rest of the apparatuslwill trace the con--- excont'act 52 is connected to the main conductor 27 by conductor .27. h When an operator moves the plvoted lever 51 of switch necting-circuits and describe theoperation of 'the'parts above described; T

50 to the left, a circuit is closed thereby between contacts 52 and 53 and a current will flow from main 27, conductor'27"-,-co'ntacts 52an'd 53, which are now bridged by dpivoted ing 33, and conductor 28 to main line conductor 28. Magnet 30 will be energized thereby and 'will raise its core 32 and. its connected parts, so that'movable contacts 37 38,and

39 will be closed against stationary contacts 34, 35, and 36, respectively. Main line conductor 26 is connected to contact 39, and as this isn-ow in contact withcontact 36 and as the latter is connectedb conductor 11 to motor-terminal 11 mainline 26will thus be Main line conductor 28 is now similarly connected, through contacts 37 'and'34 and conductor 13, to motor-terminal 13. At the- --connected to one of the motoreterminals 11. v .4

same time main line conductor 27 is con;-

ductor 12 and the circuit continues through this conductor 12 'to and through coils 63 an'd64 of an electromagnetic actuating device 60, which will'be described later, and

through conductor 12 to the centralmotorterminals 12. .In this manner the motor ma be connected to the source of supply and wil begin to rotate in one direction. When nected, through contacts 38 and 35, to c'onpivoted lever 51 'is moved back to central po- Y 33 willbe broken and magnet 30 will be deenergizedl It will then allow its core and its connected movable contacts to dro the cur rent-sup ly will be cut ofi' from t .e motor, and the atter will come to rest. If the o erator had-moved pivoted lever51' to t e right, the operation would have been similar;-

been energized and would have closed main 28 to motor-terminal 11 through contacts 49 through-contacts 48 and 45, and main 26 to sition, the circuit through magnet-winding .but in this case the magnet 40 would have i and. 46, main- 27 to'.motor -terminals 12 motor-terminal 13 through contacts 47 and 44. This would supply current to the motor in the opposite direction and would cause it to rotate in .the op osite direction.

An Opposition element may be included in the motor-circuit to prevent its rotation from being too fast. 80 designates a star-connected resistance which is connected in series with the rotor-circuit of motor for thispurpose. Its outer ends are connected by conductors 14, 15 and 16 to brushes 14, 15, and 16, Which are connected to the rotor- Windings through rings in a well-known manner. It is desirable to gradually cut this opposition element out of the motor-circuit as the motor accelerates and to thus control its acceleration. It is also desirable that this should be done with greater or less rapidity, according to the load upon the motor, which may be a variable quantity. I will now describe an arrangement which I have invented for accomplishing these ends and for automatically controlling the acceleration of the,

motor.

60 and 70 designate electromagnetic actuating devices. 60 comprises a magnetic frame 61, preferably of laminated magnetic material, and a rotatable armature 62, which is attached to a shaft 65 and which is arranged to' swing between two pole-

pieces

61 and 61 which are a part of the ma netic frame 61. Rigidly mounted upon shaft and arranged to move in unison with armature 62 is a toothed segment 65. The armature or rotatable member ,62 is shown in the drawings in a horizontal position and situated in such a manner as to includea maximum number of magnetic lines of force which pass between pole-

pieces

61 and 61 when they are energized. It'has been shown that all the current passing from main conductor 27 to the motor 10 passes through the windings 63 64, and these are placed upon the

polepieces

61 and 61. The motor-current then will energize these pole-pieces, and this will tend to hold armature 62 in the position in which it is shown. It is also evident that this energizationwill be proportional in strength to the total motor-current. 7Q designates a similar electromagnetic actuating device. Its magnetic frame 71 ,with its polepieces, is arranged to be energized by a current passing through its coils 73 and 74. When either side of the reversing-switch S is closed, the main line conductor 27 will be connected, as has been shown, through contacts 38 35 or through contacts 48 45 to conductor 12. Another conductor 12 is attached to 12 and runs to the coil or winding 73. The other end of Winding 73 is connected to Winding 74-, and the other end of 74 is connected by conductor 74'' to the two outer stationary contacts 56 on the master-switch 50. The stationary segmental contact 55 is connected by conductor 11 to conductor 11', which We have seen is connected, through conductor 28 Whenever one side or the other It is of the reversing-switches S is closed. evident then that whenever pivoted lever 51 is moved to its extreme position to the left or right position the 'coils 73 and 74 will be connected directly across

mains

27 and 26 or 27 and 28 and in shunt with the motor. Con.- sequently the magnetic frame 71 will be energized in proportion to the voltage in the mains. The armature 72 is held normally in the position in which it is shown in the drawings. When the pole-pieces 71 71 are energized, the armature 72 and its connected toothed segment 75 will be pulled thereby in an anticlockwise direction, as the armature Will tend to move into such a position as to include the maximum number of magnetic lines. This pull will be approximately proportional to the voltage in the main line. It may be seen that each of these actuators has a tendency to pull its rotatable member into a state of'magnetic equilibrium in such a position as to include the maximum number of magnetic lines of force and that the actuators cannot move these members beyond such position.

90 designates an arm which ispivoted at 91 and which is geared to toothed segments 65 and 75 by other toothed segments 92 92. An adjustable weight 90 at one end of this arm tends to keep the parts normally in the positions in which they are shown in the drawings; The arm 90 is connected by a link 93 to a sliding frame 94,.in Fig. 1, to the upper end of which-is attached a core 95, which is arranged to be moved out of and into a choking-coil 96. Mountedupon the top of the frame 94, but insulated from it, is a contact-plate 97, above which are placed three

stationary contacts

97, 97, and 97 which are connected-to the outer terminals of resistance and to brushes 14, 15, and 16 on the motor 10. Upon one side of frame 94 is placed a 'block of insulating material 98 which carries a contact-strip 98. A stationary brush 99 bears upon this contact-strip when the parts are in the position shown.

1, 2, and 3 designate three electromagnets. The magnet 1 comprises a frame 1, a core 1 ,anda winding 1 It also has in conjunction with it three stationary contacts 1, 1 and I which are connected, respectively, to points 81, 82, and 83 on resistance 80. A

contact-plate 1 is arranged to be lifted by magnet 1 against these stationary contacts when the 'magnetis sufliciently energized and to thereby short-circuit that portion of resistance 80 which is included between the points 81, 82, and 83. Magnets 2'and 3 have similar parts to those just described and are similarly connected to resistance 80.

A, conductor 12? is connected to the lefthand sidesof the three magnet-windings. 1,

2 ,and 3 and to the conductor-11*, which,

,we have seen, is connected to the main 27 whenever the reversing-switch 'S is. closed- The other ends of these magnet-wmdmg-s areconnected together and by conductor 96 ,to

"choking-coil 96, and a circuit isthen com- 'pleted through coil 96,, conductor 96, con* tact-strip 9S, brush 99, conductor 99-,tto

conductor 13", which is connected to main 28 or-main 26 when one side or the other of the reversingsWitc-hS is closed. fThus the windings ofthe magnets 1, 2, and 3 are connected when the reversing-switch is closedin parallel across two of the mains through the choking-coil 96. These magnets may be ar-- ranged to be actuated'one by one as the cur-f I rent-supply to them increases. This may be accom lished in a' number of waysas-, for examp e, by having a different number of turns in'each winding. As shown, winding 1 has the greatest number of turns, winding- 1 2 has a smaller, number, and winding 3 has the smallest number of turns. Consequently when a currentiof increasing strength is supplied to these magnets they will be energized sufficiently to lift their cores-in succession.

I will now describe the operation of the electroma' etic actuating devices and the parts whicithey control.

When the'operator moves pivoted lever 51 of master-switch Way overto the left or right, and therebystarts the motor in one di-.

rection or the other, the actuating devices Wlll both be energized, as we have seen. Ac'

tuating device 70, which is energized in proportion to the'amountof voltage in the main ines, will through its connected parts tend to lifathe weighted end of arm 90 and-the slid- {l st-ed that the arm 90wi ing frame .94. The tendency of actuating device is to prevent suchmovement, and the parts may beso proportioned and ad- I l not be moved so ong as the motor-,cu'rrent which energizes the actuating device 60 isv of a certain 'prede 'termined strength. As the motor accelerates this current willdecrease, and conse:

- quently the retarding andholding effect of netic material, and is itself constructed of laminated magnetic material, and the impedance of coil 96 is sufficiently hi h to prevent enough current to'pass throng it to cause ./n1agnets 1, 2-, or to -lifttheir cores. Now

when core 95 is raised a certain amount this decreases the impedance of: coil 96 and allows. more current to pass through it and through magnets 1, 2, and 3. When c0re95 is raised far enough tie allow enough current to pass to energize magnet 1 sufficientlyfor it to raise its core, t will do so and wll bring contact platc 1* up against stationary contacts plate; 97 will be gig 1 -1 and I and will thus short-circuit that portion of resistance 80 whlch lies be This will tween the points 81, 82, and 831 allow the motor to take more current, which 7 will of course increase its acceleration andat the same time increase the holding or ret'ard ing-effect oi actuating device, 60 and prevent 1 a further movement of core 95 until the motor-current has again decreased. Then actuating device will raise core 95 farther until it allows enough current to pass to cause magnet 2 to raise its core-2 and thus short-circuit another portion of resistance 80..

Similarly ,magnetffi will be actuated and short' circuit a further portion of resistance 80. Finally,actuating device 70 will raise core-95 to,its extreme upper position, when contact-

f contacts

97, 97 and 97 and will thereb short-circuit all of resistance 80. allow motor 10 to take full power from the line and -to attain maximum s eed. ,At'the same time sliding frame 94 wi he raised up to such a'position as to cause the stationary brush 99 to run off of contactestri 98 and onto insulating-block 98*.

rought against stationary This wi l.

the current from magnets 1, 2, and 3'and Erevent' unnecessary currentconsumption v themafter they ha'veperformed their function.- Then the current is cut ofi from the motor and from the .iectromagnetic ac-z tuatingdevices', v Weight will immediately bring the arm 90 and its connected parts back to their initial o's'ition.

- The operation a ove described-is automatic; Means may be provided, however,

for giving an operator partial control-of the For. this 'pur ose- I have prooperation. vided'the resistances 57, w "ch are connected to g the stationary contacts 56. It is obvious-that the operator mayinclude more or less of this resistance in circuit with coils 73 'and' 74'by moving pivoted lever 51 onto one or another of stationary contacts 56. Thushe may retard the action of actuatin [device 70 and the acceleration of the motor ut he cannot increase its action and thus cause the motor to accelerate too ra idly.

It is sometimes desirab e to furthergovern the movement of arm'90, and for this purpose a mechanical retarding device 100 may be provided. A third toothed segment 92 is shown on one end of'arm 90, and this is in -meshwith a pinionlOl, which is attachedto a ratchetwheel1102' A: ear wheel 103 carries a pawl 104' and mes es with the pinion 105, upon the shaft of which are mounted two fan-blades 106.' These may been arranged that they maybe moved in or out from-the shaft, so that their retarding efiect maybe adjusted. When arm 90 is moved to raise its weighted end, the mechanism just de{ scribed will drive fan-blades 106, and these will retard the movement of arm 90 in that direction. The ratchet-and-pawl v arrange tem similar to that already described. The

resistance 80 is shown delta-connected. The

excitingcoils

63 and 64 of electromagnetic actuating device 60 instead of being connected in series and in the central main line conductor 27 are shown separate, with

coils

63 and 64 connected in series with the outside main line conductors 26 and 28. Pivoted arm 90 is connected by link 93 to a sliding member 94, which in this case is a cam memher which controls the movement of a series of ivoted arms 120 and allows them to mal e contact with-or moves them away'from a corres onding series of stationary contacts 121. T ese pivoted arms and stationa'rycontacts may be connected to resistance 80 and may be arranged to short-circuit the latter directly without the intervention of electromagnets when the arm 9G, withits connected parts, is raised.

Fig. 3 illustrates another modification. of my invention and shows that it is applicable to single-phase circuits. here shown as a series-connected single-phase motor. The main line conductors 20- 22 are shown connected to the rimary of a regulating transformer 130. everal points of the secondary of this regulating-transformer are connected to stationary contacts 131, one or another of which may be connected to a contact-strip 132 by a sliding contact 133, mounted upon a sliding rod 134. Contactstrip' 132 is connected to the motor 10 through reversing-switch. Sliding contact 133 may be arranged to be moved by the arm 90 and to include more and more of the secondary of regulating-transformer 130 in the motor-circuit and to thus supply the'mo- 4 tor with an increasing voltage as it accelerates, which voltage may be controlled and regulated by means of the apparatusand de vices previously described in this specification.

When this invention is applied to a motorstarting device, the acceleration of the motor will depend upon the totalamount of motor-current, upon the voltage of the line, upon the efi'ect of the mechanical retarding device, and upon the position of the master'- switch 50. ,The actuator has a retarding eiiect upon the actuator and their con nected parts, as well as a holding efiect. It may, in fact, if the motor-current becomes excessive push arm 90 down, and thus cause a reduction of the motor-current.

As thevarious magnet-winding actuatorcoils may be connected across two of the mains, as described, it is evident that they may be arranged to be actuated by singlephase currents.

The motor 10 is for the rotating members swing freely b etwcen their respective pole-pieces and do not touch them. The two rotating members tend to balance themselves between their respective pole-piecesv and of coursemust act in unison, actuated by the differential action of the 0111161111 in each. Moreover, the two rotating members are mechanicallyconnected together, and as they exert pulls in opposite directions upon the gears thelatter Will not chatter.- v

This invention is applicable to many. other uses than those herein shown and-described. I have shown it as appliedto a IllQbOIrStSIting system, as this is one of its advantageous uses. I

The controlled motor may be connected to run elevators, cranes, mill-tables, or railroad-cars or to any similar use where it is desirable to have a steadily-increasing current supplied to the motor and a. current which cannot be increased beyond a safe amount by'the carelessness of an operator. It may of course also be used in many other connections where it is desired to automatic- .of current in electromagnetic actuating de- .'v1ce 7 0, such as a change of,volta e in the line. would cause, would have a li e effect.

This is a valuable feature and it increases the usefulness of this invention.

What I claim. is

1. An electric circuit for alternatingcurrents, an electromagnetic actuatorin series therewith, and a second electromagnetic actuatorin shunt therewith,..sai d, actuators having rotatable members mechanically connected to oppose each other.

2. An electric circuit for alternating currents, an. opposition element therein, an'electromagnetic actuator in series with the cir-' cuit, and a second electromagnetic actuator in shunt with the circuit, said actuatorshaving rotatable members which are mechanically connected together and arran ed to control the opposition element. 3. An electric circuit foralterneting currents, an opposition element therein, an

electromagneticactuator, in series with the circuit, a second electromagnetic actuator in shunt with the circuit, a retarding device for the actuators, said actuators having rotatable members which are mechanically connected to oppose each other and arranged to control the opposition element.

{1. A motor, a source of alternating-current supply, and means for automatically controlling the acceleration ofthe motor, said means comprising an electromagnetic actuator, in shunt with the'motor, and a second-"electromagnetic actuator in series with the motor, said actuators having rotatable members, each of which members has a magneticallyequilibrated position.

,5. A motor, a starting-switch therefor, a

source of alternating-current supply, and

means for automatically controlling the acceleration of the motor, said means comprising an electromagnetic actuator in shunt with the motor, and asecond 'electromag' netic actuator in series with the motor, said actuators having rotatable members, each of which "members has a magnetically-equilibrated position."

6. A motor, an electrically-actuated re-- tor, said means comprising an electromagnetic actuator in shunt with the motor, and; a second electromagnetm actuator in series with the motor, said actuators having rotatable members, each of which members has a magnetically-equilibrated position, and a manually-operated switch for'controlling the reversing-switch.

8. A motor, anelectrically-actuated reversingeswitch therefor, a source of alternating-current supply, means for automatically controlling the acceleration of the motor, said means comprising an electromagnetic actuator in. shunt with the motor, and a 'sec-' ond electromagnetic actuator in series with the motor, and. a manually-operated switch for controlling the reversing-switch and the action of the electromagnetic actuators. 9. A motor, a source of alternating-current supply, an opposition element in the motorc'i'rcuit, means for gradually cutting said opposition elementout of the motor-circuit in proportion to the acceleration of the motor, said means comprising an electromagnetic actuator in shunt with the motor and a second electromagnetic actuator in series with the motor, said actuators having rotatable members, each of which members has a'magnete ically-equilibrated position.

10. A motor, a source of alternating-current supply, an opposition element in the motor-circuit, means for gradually cutting said.

opposition element out of the motor-circuit in proportion to the acceleration of the motor, said means comprising an electromagnetic actuator in shunt with the motor, and a second electromagnetic actuator in series with the motor arranged to oppose the action of said first actuator, said actuators having rotatable members, each ofwhich members has a magnetically-equilibrated position.

1 1. A -motor, a source of alternating-cur rent supply, a resistance inthe motor-circuit,

a plurality of electromagnets arranged to short-circuit the resistance in a number'of steps, and means for actuating the magnets one by one in proportion to the acceleration of the motor, said means comprising an electromagnetic actuator in shunt with the motor, and a second electromagnetic actuator in series with the motor and arranged'to oppose the action of said first actuator.

12. A motor, a source of alternating-cure rent supply, a resistance in the inotor ci.rcuit,

a plurality of electroina'gnets arranged to short-circuit theresistance in a number oi steps, circuits forthe magnets, a choking coil in the magnet-circuits, and means for ac tuating the choking-coil and causing the magnets to' act one by one in proportion to the acceleration of the motor, said means comprising an electromagnetic actuator in shunt with' the motor, and, a second electromag-' netic actuator in series with the motor and arranged to oppose the action of said first aatuator.

13. A motor, a source of alternatingecurrent supply, a resistance in the mo torcircuit, a plurality of electromagnets arranged to short-circuit the resistance in a [number of steps, circuits forthe magnets, a choking coil inthe magnet-circuits, and means for ac tuating the choking-coil and causing the magnets to act. one by one in proportion to the ac.

celeration of the motor and for finally shortcircuiting the entirev resistance and opening the magnet-circuits, said means comprising anelectromagnetic actuator in shunt with the motor, and'a second electromagnetic actuatorin series with the motor and arranged to oppose the action of said first actuator.

14. A'motor, a reversingswitch therefor, a

source of alternating-current supply, a re- 1 sistance in the motor-circuit, a plurality of electromagnets arranged to short-circuit the resistance in a number of steps, means for actuating the magnets one by one in proportion to the acceleration of the motor, said means comprising an electromagnetic actuator 1n shunt with the motor, and a second electromagnetic actuator in series with tlie notor and arranged to oppose the action of said first actuator, and a retarding device for said actuators. r

15. A'motor, an e1ectrica1ly=actuated reversing-switch therefor, a source of alternat ing-current supply ,a resistance in the motor circuit, a plurality of electromagnets ar ranged to short-circuit the resistance in a number. of steps, meansi'or actuating the magnets one by one in proportion to the ac celeration of the motor, said means comprising'an electrom agnetic actuator in shun t with the motor, and ase'cond electromagnetic actuator in series with the motor and arra ed to oppose the action of said first a.cti 1 r, IO and a manuallyoperated switch for controlling the reversing-switch.

16. A ,motor, an electrics l ,*-actuated rcversing switch therefor, a source of altcrnat- 'ing current su ply, a resistance in the motor- I 5 circuit, a pluraity'of electron'iagncts arranged to short-circuit the resistance in a number of steps, means for actuating the magnets one by one in proportion to the coloration of the motor, said means comprning an electro magnetic actuator in shunt with the motor,

and a-second electromagnetic actuator in se' ries with the motor and arranged to oppose the action of said first actuator, and a manually-operatedswitch for controlling the re 2 5 versing su'itchand for retarding the action of the actuating means,

17. A motor, an electrically--actuated reyersing-switch therefor, a source of alternatin'g-current supply, resistance in the motorcircuit, aplurality of electromagnets arranged to short circuit the resistance in a number of steps, means for actuating the magnets one by one in proportion to the acceleration of the motor, said means ctmiprising an electromagnetic actuator in shunt with the motor,

and a second electromagnetic actuator in series with the motor and arranged to oppose the action of said first actuator, a manuallyoperated switch for controlling the reversing 4o switch and for decreasing the effect of themtuating means, and an adjustable retarding device for the actuators.-

18. A source of alternating-current supply, a circuit connected therewith, means for varying the current in said circuit, a magnetic-actuatorcomprisinga rotatable member of magnetic material and a winding in shunt to'the circuit; and a second magnetic actu ator comprising a rotatable member of mag- B81716 material and a winding in series with the circuit, said actuators being arranged to control the current-varying means.

19. A. source of alternating-current. sup

ply, a circuit connected therewith, means for varying the current in said circuit, a magnetic actuator comprising a'rotatable memher, a field of laminated magnetic material and awinding for the field; said winding be ing in shunt to the circuit and a second magnetic actuator comprising a rotatable member, a field of laminated magnetic material and a Winding for said field; said winding'being in series with the circuit, said rotatable membersbeing arranged to control the our- 6 5 rent-varying means.

sponsive device for controlling the opposi- 20. i'l' source of alternating-current supply,a circuit connected therewith, means for varying the current in said circuit, a magnetic actuator comprising a rotatable member of laminated magnetic material, a frame of laminated magnetic material and a winding for the frame; said winding being in shunt to the circuit; and a second magnetic actuator comprising a-rotatable member of laminated. magnetic material, aframe of lami- 7 5 nated magnetic material and a winding for the frame; said winding being in series with the circuit; said. rotatable members being mechanically geared together and arranged to control the currentvarying means. 8o

21. A source of alternating-current supply, a circuit connected therewith, means for varying the'current in said circuit, a magnetic actuator comprising a rotatable member of laminated n'iagnetic material, a field of laminated magnetic material and a winding for the field; said winding being in shunt to the motor; a' second magnetic actuator, comprising a rotatable member of laminated magnetic material, a field of laminated. magge netic material and a winding for said field said winding being in series with the circuit; said rotatable members being mechanically geared together and to a lever which is arranged to control the current-varying means, 5 and an adjustable weight on said lever.

22. A source ofalternating-current sup ply, a circuit connected therewith, an inductive mcans"'for varying the current in said circuit, a magnetic actuator comprising a rotatable member and a winding in shunt to the circuit; and a second magnetic actuator comprisin a rotatable memberwand a wind ing in series with the circuit, sal'd actuators being arranged to mechanically control the inductive-current-v arying means.

A source of alternating-current supply, a circuit connected therewith, an opposition element in said circuit, an electrorctoo I I 0 tion element, inductive means for controlling the electroresponsive device, a magnetic actuator comprising a rotatable member of magnetic material and a winding in shunt to the circuit, and a second magnetic actuator comprising a rotatable member of magnetic material and a winding in series with the circuit, said actuators being arranged to'control the inductive'current varying means,

24. A source of alternating-current supply, a circuit connected therewith, means for varying the current in said circuit, a magnetic actuator comprising a rotatableniember of laminated magnetic material, a frame of laminated magnetic material and a. winding for the frame; said Winding being in shunt to the circuit, and a second magnetic actuator comprising a rotatable member of laminated magnetic material,. a frame of lan1imated magnetic. material and a winding for 1 0 IIS ' ing the action of the actuators.

25. A source of alternating-current supply, a circuit connected therewith, means for varying the current in said circuit, a mag netic actuator comprising a rotatable member of laminated magnetic material, a frame of laminated magnetic material and a winding for the frame; said winding being in shunt to the circuit, and a second magnetic actuator comprising a rotatable member of laminated magnetic material, a frame of laminated magnetic material and a windingfor the frame; said winding being in series with the circuit, and means for electrically retarding the action of the actuators and additional means for mechanically retarding the action of the actuators.

26 A source of alternating-current supply, a circuit connected therewith, means for varying the current in said circuit, a magnetic actuator comprising a rotatable mem-' ber of laminated magnetic material, a frame of laminated magnetic material and a winding for the frame; said winding being in shunt to the circuit, and a secondmagnetic actuator comprising a rotatable member of laminated magnetic material, a frame of laminated magnetic material and a winding for the frame; said winding being in series with the circuit, and manually-operated means for adjustably decreasing the current in said shunt-winding, and additional means for retarding the movement of the actuators.

27. A motor, a source of alternating-current supply therefor, means for varying the current 1n themotor, a magnetic actuator comprising a rotatable member of laminated magnetic material, a frame of laminated magnetic material and a winding for the frame; said winding being in shunt to the motor; and a second magnetic actuator com-.

' prising a rotatable member of laminated magnetic material, a frame of laminated magnetic materialand a winding for the frame; said winding being in series with the motor; said rotatable members being 'mechanically geared together and arranged to control the current-varyingmeans. 4

28. A motor, a source of alternating-current supply therefor, an opposition element in the motor-circuit, an electroresponslve device for controlling the opposition element, inductive means for controlling the electro responsive-device. a magnetic actuator'comprising a rotatable member of magnetic material and a winding in shunt to the motor, and a second magnetic actuator eompri'sin a rotatable member of magnetic materifi and a winding in series with the motor, said actuators being arranged to control the in-' ductive-current-varying means.

29. A motor, a source' of alternating-cur rent supply therefor, a resistance in the moand awinding in shunt to the motor; a second magnetic actuator comprising a rotatable member and a winding in series with the motor, said rotating members being mechanically connected together and to the inductive means, and arranged to cause said inductive means to control the electroresponsive device to remove the resistance from the motor-circuit.

30. A motor, a source of alternating-current supply therefor, a resistance in the motor-circuit, an electroresponsive device comprising a plurality of ma nets arranged to control the resistance, in uctive means arranged. to control the electroresponsive device, a magnetic actuatoreomprisin a rotatable member of magneticfmateria, and a winding in shunt to the motor; a second magmeans tocontrol the magnets to cut the resistance out of the motor-circuit ste by step.-"

31. A motor, a ,startingswitch t erefor, a

source of alternating-current supply, means for automatically controlling the acceleratlon of the motor, said means comprising an electromagnetic actuator having a rotatable member and a winding in shunt with the. motor, a-second electromagnetic actuator having a rotatable member and a winding in series with the motor and means combined with the starting-switch for controlling said actuator-windings. 1

32. A motor, 'an electricallyactuated re" versin'gswitch therefor, a source of alternating-current supply, means for automatically controlling the acceleration of the motor,

said means comprising an electromagnetic actuator having a rotatablamember a'nd'a' winding in shunt'with the motor, and a sec-' ond electromagnetic actuator having a rotatable member and a winding in series With ,the motorcircuits' for said windings, means combined with the reversing-switch for elos ing and opening the circuits for the actuator windings, and a manually-operated switch arranged to control the reversing-switch and ,to vcontrol and regulate the action ofthe.

electromagnetic actuators. 4

-33. A multiphase alternating-current motor, a source of multiphase alternating-cur rent supply and means for automatically controlling the accelerationof the 'motor,.

said means comprising a magnetic actuator in shunt with the motor and a second -mag-v nctic actuator in series with the motor, said actuators being arranged to be energized by a single-phase curren l 34. A multiphase alternating-current motor, a source of multiphase alternating-urn rent supply therefor, an electrically-actuated reversing-switch for the motor and means for automatically controlling the acceleration of the motor, said means comprising an electromagnetic actuator in shunt with the motor, and a second magnetic actuator in series with the motor, and a manually-operated switch for controlling the reversingswitch and'the action of the electromagnetic actuators, said reversingswitch and actuators being arranged to be energized by a single-phase current. v I v 35. A multiphase alternating-current motor, asource of multiphase alternating-current supply therefor, an e'lectrically-actuated reversing-switch for the motor,'an electroresponsive device comprising a plurality of magnets arranged to control theresistance, inductive means arranged to control the electroresponsive device, a magnetic actuator comprising a rotatable member of magnetic material and a winding in shunt with the mo tor; a second magnetic actuator comprising a rotatable member and a Winding in se ies with the motor, said rotatable members being mechanically connected together and to the inductive means, and arranged to cut the resistance out of the motor-circuit step by step, anda manually-operated switch arranged to control the reversing-snitch and to control-and regulate the action of the electromagnetic actuators, said reversing-switch, magnets, inductive means and actuators being arranged to beenergized by a singlephase current.

36. A .motor, a source of alternating-current supply therefor, an opposition element in the motor-circuit, a plurality of electromagnets, inductive means arranged to control the magnets and an electromagnetic actuator having a rotatable member, said memher being arranged to mechanically control the inductive means.

37. A motor, a source of alternating-cur rent supply therefor, an opposition element in the motor-circuit, a plurality of electromagnets, inductlve means arranged to con-.

trol the magnets and an electromagnetic a'ctuator having a rotatable member, said member being arranged to mechanically control the inductive means to cause the magnets to be actuatedstep by step in proportion to the speed of the motor.

38. A motor, a source of alternating-current supply therefor, an opposition element in the motorecircuit, a plurality of electromagnets, inductive means arranged to control the magnets, an electromagnetic actuator having a rotatablemember, said member 40. A motoiya source of alternating-min rent supply therefor, an opposition element in the motorcircuit, an electroresponsiveldevice arranged to control theoppositionelement, circuits for said electroresponsive device, inductive means in the said circuits and an electromagnetic actuator arranged to control the inductive means;

41. A motor, a source of altcrnating-current supply therefor, a resistance in the motor-circuit, a series of electromagnets each arranged to short-circuit a part of said resistance, an inductive device arranged to dontrol;the magnets, a magnetic actuating device dependent upon the motor-current and the voltage of the supply, mechanically 'connected to the inductive device and arranged to move the inductive device to cause the magnets to be actuated step by step and to finally effect the short-circuiting of the entire resistance.

42. A motor, a source of alternating-current supply, a resistance 1n the motor-circuit,

a' series of electromagnets each arranged to short-circuit a portion of the resistance, an

inductive device to control the magnets, elec' tromagnetic actuating means dependent upon the current in the motor and the voltage of the sup 1y, mechanically connected to the inductive evice and means mechanically connected to the actuating means for shortcircuiting the final portion of the resistance and cutting out the magnets and the inductive device.

43. A motor, a source of alternating-current supply therefor, an opposition element 1 1n the motor-circuit, an electromagnetic actuator arranged to control said opposition element, said actuator having a circuit in series with the motor and another circuit in shunt with the motor; and manually-operated means for controlling the current in the shunt-circuit.

44. An alternating-current motor, a circuit therefor, an opposition element in the motor-circuit,'an electroresponsive device arranged to control said opposition element, inductive means arranged to control the electroresponsive device, and an electromagnetic actuator arranged to.control the inductive means.

45. An alternating-current motor, a ciI cuit therefor, an opposition element in the an alternating-current motor, a circuit t 00-),VOU-

motor-circuit, an electroresponsive device arranged to control said opposition element, inductive means arranged to control the electroresponsive device, and an electromagnetic actuator arranged to control the inductive ranged to cut the opposition element out of the motor-circuit step bystep, circuits for v the electroresponsive device, inductive means arranged to control the current :in said circuit, and an electromagnetic actuator'arranged to control the inductive means.

48. An alternating-current motor, a circuit therefor, an opposition element in the motor-circuit, an electroresponsive device arranged to cut the opposition element out of the motor-circuit step by step, circuits for the electroresponsive device, inductive means arranged to control the current in said circuits, an electromagnetic actuator arranged to control the inductive means, and retarding means for the actuator. 6

4'9. An alternating-current motor, a circuit therefor, an oppositionelement in the motor-circuit, an electroresponsive device arranged. to cut the oppositionelement out of the motor-circuit ste by step, circuits for the electroresponsive evice, inductive means arranged to control the current in said cir-- cuits, an electromagnetic actuator arranged to control the mductlve means, a mechanlcal retardln device for the actuator, and an elect'rica' retarding device for the-actuator.

50. A controlling device, comprising two rotatable members constructed oflaminated magnetic material, said rotatable members being mechanically connected together .and

each of said members having a magneticallyequilibrated position.

51. A-oontrolling device, com rising two rotatable members constructed 0 laminated magnetic material, said rotatable members being mechanically connected together and each of said members having a magneticallyequilibrated position, and means for magnet-' izing said members.

52. A controlling device comprising two rotatable members constructed of laminated magnetic material, said rotatable members being mechanically connected together, a source of alternating-current supply arranged to magnetize said members, each oi" said members having a magnetically-equilibrated position; and means for controlling saidsource of supply.

53. An a ternating-current motor, means for controlling said motor, said means comprising .two rotatable members constructed .of laminated magnetic material, and said rotatable members being mechancially connected together, each of said members having a magnetically-equilibrated position.

54. An alternating-current motor, a circuit therefor, an opposition element in the motor-circuit, means for controlling said opposition element, said means com rising two rotatable members constructed 0 laminated magnetic material, and said rotatable members being mechanically connected together, each of said members having a magneticallyequilibrated position.

55. An alternating-current motor, a circuit therefor, an opposition element in the motor-circuit, means for controlling said opposltion element 1n pro ortion to the speed of the'motor, said contro ling means compris- I ing two rotatable members constructed of laminated magnetic material, and said rota'- table members bein mechanically connected together, each of sai members having a mag netically-equilibrated position.

In testimony whereof I have signedlmy name to this specification in the presence of two subscribing witnesses.

DAVID LARSON.

Witnesses:

JOSEPH E. OAVANAUGH, EnNEs'r W. MARSHALL.