US1089920A - Current-controlling apparatus. - Google Patents

Description

E. L. GALE, SB.- GUBRENT CONTROLLING APPARATUS. APPLICATION FILED mm: 11, 1907.

1,089,920, Patented Mar. 10, 1914.

. A an 00 "ypkoz u h M20005 I 1111 TED srarns PATENT v orrios.

ERNEST L, GALE, SB, OF YONICERS, NEW YORK, ASSIGNOR TO OTIS ELEVATOR OOMPANY, OF JERSEY CITY, JERSEY, A CORPORATION OF NEW JERSEY.

oURRENT-ooNrnoLLING APPARATUQ'S.

To all whom it may concern Be it known that I, Ennns'r L. GALE, Sr.,

a citizen of the United States, residing at Yonkers, in the county of Westchester and State of New York, have invented a new and useful Improvement in Current-Controlling Apparatus, of which the. following is a specification.

, My invention relates to apparatus for con-; trolling electric currents,-and although here in shown as applied to electric motors, 1t

maly have a general application. he object of my invention is the provision of improved and simplified construc.-.

tion which will consume miniinumcurrent during the starting and operation of a translating device controlled by electric current. Another object of my invention is the provision of means for absorbing the field dis charge to prevent sparking orarcing at those points Where the continuity of conductors is interrupted. Other objects of my invention will appear hereinafter. v

The accompanying drawing illustrates diagrammatically in a single view, one arrangementfor carryingo-ut the objects of my invention. It is obvious, however, that those skilled in theart may make various changes in the details and arrangement of parts without departing from the spirit and scope of my invention as defined by the claims, and I desire, therefore, not to be limited to the precise constructlon herein disclosed. 1

Referring to the drawing, 1 designates a motor-armature, and 9 a shunt field circuit therefor connected between the pointl of the positive main and the point 15 .con-

nected to the negative main, 'so that the shunt field circuit will be connected across the mains when the switch 10 is closed.

1*, 4 and 4 designate sections of starting resistance. Theform of the starting resistance will depend upon the nature of the current, that. is, whether it is direct, intermittent, alternating, etc. The main armature circuit is shown by the heavy black lines and extends between the main and the main, and includes the armature 1, sectional starting resistance and the switch 10.

Connected to the terminals of the sections ofthe resistances 4*, 4 4 are, respectively, the contacts 5, 5 5 so, that when the re- -sistance-varying members 7*, 7 7 are in to the negative 1 main.

connected between the point 25 of the con p Specification of Letters, Patent. Patented :Man 10, 191 4, Application fild June 11, 190-7. Serial Nb. 318,409.

engagement with said contacts, the resistances will be short-circ'uited. These resistance-vary1ng members are carried by and movable with the cores or plunge rs8 8 8 ?-Wl1l0l1 are movable in the solenoids 2 2 2 The solenoid 2 is connected be tween 'the.

point 24 and the conductor 23 by the-conductor 20.- The conductor 23' leads to the manual switch 3 which in turn 1s connected The'solenoid 2 is ductor 27 .and'the conductor 23 by means of the conductor 21. And'the solenoid 2 is connected between the oint 26 and the conductor 23 by means o the conductor 22.

The series of electro magnets as shown are preferably so'arranged that they will be operated successively to lifttheir cores when they receive current. This, however, is not of so much importance. in'thi's particular arrangement, but it is important that the cores should be allowed to descend in serial or successive order so that the sectional starting resistance may be gradually cut out. In this instance this is accomplished by meansof the stop screws 46', 46 46 mounted in fixed supports 17. 'These stop screws limit the upward movement of the cores so that a less number "of ampere turns will be acting on the core 8 than on the core 8 and less on the latter than on the core 8*.

For the sake of convenience, I may term the circuits including the solenoids 2 2 and 2 as controlling circuits in parallel with each other. The solenoid 2*, when both switches 3 and 10 are closed, is connected in parallel to the entire starting resistance ,provided all of the resistance-varying members are in their upper positions as shown. At this time also the. solenoid 2 is n parallel to the sections 4 and 4 The movement of the core 8 and the resistance-varying mem her 7 connected thereto, may be timed, if desired, by the addition of a retarding device, as, for example the dash-pot 17, which permits free upward movement but retards downward movement. The operation of the invention thus far described may be stated as follows: Assuming that the switch 10 is open and the switch 3 closed, and the positive and negative mains disconnected from the source of current supply, the resistance-varying members will be held in their normal or lower positions by the weight of the plungers connected therearmature l, resistance 4:,

- switches l0 and 3 should It will be seen 'sistance-varying member stance, through the usual two-pole switch, otential to the motor may receive sufficient eiiect the starting of the same, ut preferably, the solenoids are of sufiicient resistance so that the current permitted to flow at this time will have 1 no appreciable effect upon the motor armature. Current will now flow from the positive main through the armaturel, conductor 20, solenoid 2 conductor 23, and switch 3 to the negative main. will thus be seen that the armature land solenoid 2 are connected in series with each other." Current will flow also through the and solenoid2 in series with each other; and also through armature 1, sections 43,4 and 4 conductor,

22, and solenoid 2 in series with each other.

The solenoids 2 '2 desired. Itis evident, however that igfithe.

of the core'8 with respect is such that the resistance- 7 is lifted first, the currelative position to the solenoid 2 varyin member rent w ich flows through out down by the resistance 4*, and it the re- 7 is lifted before 7 the solenoid 2 has its current further reduced by all the sections 4, 4: 4:.

If it is assumed that the and mains as represented are already connected to the then both the be normally in Then upon closing the source of current supply,

open posit on.

switch 3, the electro-magnetic switches will.

be operated to open positions to place the sectional starting resistance in} readiness to be connected in series with the anotor-armature in the main armature circuit when the switch 10 is closed. As before stated, when the series of electrmm'agnets'are"operated, preferably the armature does not receive sufficient current to start the same, but upon closing the switch" 10'the armature circuit is closed and the armature may start, that as soon as the switch 10' is closed, the solenoid 2 is at once shortcircuited, so that substantially no current flows through the latter, and since no m ,tarding influence is exerted by diminishing .ture to acquire a It" of the section 4 and 2 will, therefore; be excited with current to effect the lifting 5 the solenoid all of the solenoids may pick up that when the section 4 the solenoid 2 is I *rent isthat designated so as to cause the current in the 'solenoid-2 an external re tarding device, namely, added as a time element to permit the armahigher speed, or such a speed that the counter-electro motive force will be increased. After a short interval, the resistance varying member 7 will connect the contacts-59m short-circuit the sec tion 4 and permit more potential to be applied to the motor-armature, thus increasing thecu-rrent through the latter and cansing the same to accelerate to a higher speed.

the. dash-pot 17, is

It will be noticed that theshort-circuiting crease in speed of the motor, but depends upon theiexternal retardingdevice 17. This section-dqm ay be used for cutting downthe is independent of the instarting current to a minimum, that is, letting through less current-than is absolutely necessary in'starting a predeterminedmaximum load, the latter current being controlled by the resistances 4, 4

W hlle the resistance-varying member 7 is still out of-engagement with the contacts 2 is connected across the sections 4 and 4, but when the section 4 is -short-circuited or cut out, then the sole- 'noid 2 is connected only across the section 4*. Now after the motor attains-a predetermined speed and acquires a corresponding counter-electromotive force, the solenoid 2 begins-to-release its core 8 and resistance-varying member 7 connected thereto descends until the section. 4 is short-circuited, .when the motor starts to accelerate to still higher'speed. It should be. noted isshort-circuited on cut out,'the current through the solenoid 2 is also-short-circuited or substantially eleminated." The only solenoidn'ow receiving C111- 2 and the main armature current flows through the armature and the single sections P.- At this time the solenoid 2 is connected across the sec--, tion 4,

and when the counter-electromotive force in the armature, increases still further potential across the section 4* to decrease, the current through the solenoid 2 will gradually decrease to per mit the core 8 to descend and finally cut out. the section 4* and also the solenoid itself. All the sectional starting resistance is,

therefore, cut out and all the solenoids are short-circuited', so that substantially all the current flows through the armature and the shunt field circu1t 9. The motor can now attain its maximum speed. i The arrangement described is often desirable as it gives a wide variation of the potential on which depends the operation of the controlling circuits including the conductors 20 and 21.

When a-controlling apparatus such as dey scribed is used in'connection with a' direct,

current shunt motor," I, prefer to connect an extra field 0111011115 9 permanently across the 1 currents.

resistance elements 4:, 4 and et as, for example, between the points 11 and 18. It is evident that when the motor is started and the-sectional resistances inserted in the normally-open main armature circuit, the extra field 9- is also inserted, and will, therefore, have an appreciable effect in increasing the starting torque, depending upon the amount of the starting resistance. The main objectof the extra field, however, is to absorb the field discharge or kick due to the shunt field self-induction, and thus pre-' vent the armature from having its insulation punctured by high potential induced When the current is shut-01f from the motor to stop it, as by the opening of the switch 10, the extra field circuit will remain closed through the-armature resistance or the short-circuiting pairs of contacts. The action here is similar to that or the transformer, the extra field circuit 9 acting like a short-circuited secondary to reduce the self-induction in the shunt coil 9 which acts as a primary. When the current is cut off from the motor the tendency of the shunt field circuit 9 will be to maintain the can rent and thus produce an extra current which finds a paththrough the armature 1.,

This circuit isthe primary circuit. The extra field circuit being in close proximity to the shunt field circuit and being closed externally through low resistance conductors,

will act as a short-circuited secondary. This sho-rt-circuited secondary has induced in it a current which re-acts on the primary to reduce the shunt field discharge and, therefore, protect the motor. This arrangement avoids the use of any extra current consuming resistances, switches, etc., which are at present often used and so connected that they consume current at all times when the motor is operated. 'It will, therefore, be seen that the extra field circuit 9' not only increases the starting torque, but also protects the motor in stopping, and this with minimum consumption of current, as it is short-circuited, when the motor is under normal operation.

Having thus fully decribed my invention, what I claim and desire to have protected by Letters Patent ot the United States is 1. In motor controlling apparatus, the

combination with an electric motor, of an clectro-magnet connected directly in series with the motor-armature, sectional starting resistance, an additional electro-magnet in multiple with said first-named electro-magnetand connected in series with the motorarmature through a section of said sectionalstarting resistance, a third electro-magnet in multiple with the first two-named electro-magnets and in series with the motorarmature and the entire sectional starting resistance, a switch operated by each of said electro-magnets to control said sectional starting resistance, a switch for closing the main armatureicircuit and short-circultmg the third electro-magnet, and a retarding device for the last-named electro-magnet,

the second-named and first-named electro- -magnets successively permitting their respective switches to operate successively to gradually cut out the remainder of the sectional starting resistance and to substan-' tially eliminate the current flowing through themselves.

2. In a' motor controlling apparatus,the

combination with a motor-armature, of-a shunt field circuit, resistance 1n series with the motor-armature, a controlling circult connected across said resistance, means opfield winding starting resistance in series with the motor armature, means for controlling said starti ng resistance, and an extra field circuit connected permanently to said starting resistance to absorb the field discharge of the said field winding when the current thereto is reduced.

4. In motor-controlling apparatus,

ing resistance therefor, means for controlling said resistance, and an extra field circuit connected to said resistance'to effect the absorption of the counter-electromotive force of self-induction in' the shunt field when the main line current to the motor is cut off.

5. In motor-controlling apparatus, the combination with a shunt motor, of starting resistance therefor, of means for controlling said resistance to cut out the same as the motor accelerates in speed, and to the combination with a shunt motor, of start- 9 maintain the same cut out while the motor is operating and after the main line circuit thereto is interrupted, an extra field circuit connected to the terminals of the starting resistance to increase the starting torque of the motor, and to substantlally absorb the c0unt erelectromotive force of self-induction in theshunt field circuit when the current to the motor is cut off.

(5. In motor-controlling apparatus, the combination with an electric 1notor,'of starting resistance therefor, a series of electromagnets, a corresponding series of switches operated by said electro-magnets to gradually cut out said starting resistance and to successively eliminate the current through the electro-magnets, and an extra field circuit connected permanently to the terminals of the starting resistance.

7. In motor controlling apparatus, the combination with a motor armature and its field circuit, of sectional starting resistance in series with the said motor armature, a switch in the main armature circuit, a plurality of switches for controlling said starting resis ance, controlling circuits in parallel to each other and each containing an electro-inagnet operable when energized to open said switches and place the starting resistance in the motor circuit, a switch for the said controlling circuits, and means for operating said first named swltch and said'controlling 'circuit switch independently of each other.

8. In a self-starter for electric motors, the combination with sectional starting resistance, of a plurality of switches connected to said sectional starting resistance, and a plurality of electro-magnets one for each of said switches, and .a plurality of circuits one for each ot' said electromagnets, one of said circuits being in series with some of said.resi stance, and in parallel to the rest of said resistance. I

9.111 a self-starter for electric motors, the combination with sectional starting resistance,'ofswitchesiorcontrolling the same,a

rality of -the terminals of the sectlons of said starting resistance, a plurality of electro-magnets one parallel (cont-rolling circuits,

with the motorarmature and,

'sistance, of a switch of the resistance.

11. In motor-controlling apparatus, the con bination with a motor armature and a field circuit, of sectional starting resistance in series with the mot-or armature, a pluswitches respectively connected to connected to each of said resistance sections,

the first directly in series each of the nextin series with the motor armature and a portion of the starting resistance.

12. In a self-starter for electro-magnets, the combination with sectional starting reconnected toa section thereof, an electro-magnet for operating said switch, a controlling. circuit for said starting resistance another section 0 anadditional electro-magnet for operating electro-magnet and in parallel with said an additional switch for said starting resistance,

said starting resistance, and to one resistance ,ation of the other two subscribing nose eao said additional switch, and a controlling circuit for said additional electro-magnet in series with said starting resistance.

' 13.,ln a self-starter for electric motors, the. combination with sectional starting resistance, of a switch connected to one of the sections of said resistance and initially short-circuiting the same, an electro-lnagnet for operating said switch to open the same and delay the time of re-closing the same, a switch for connecting said electro-magnet across the starting resistance and in series with the motor-armature, switch initially short-circuiting' another section oi the starting resistance, an ZtdClltionai electro-magnet in series with said starting resistance and additional switch, a main armature switch connected to short-circuit said additional electro-rnagnet, and a mechanical device for retarding the rerlosing of said additional switch. 7

14:. In motor-controlling apparatus, the combination with a motor-armature and a field circuit, of starting resistance for the motor, and an extra field circuit permanently connected at both its terminals to said starting resistance.

15. 111 motor-controlling apparatus, the combination with a motor-armature and a field circuit, of starting resistance divided into sections, electric switches connected respectively to the terminals of said sections and initially short-circuiting the same, a; series of electro-magnets operatively con-' an additional connected to said I nected to said switches in circuits parallelto the starting resistance, the last cirwith all cuit being directly in series with the motor- I armature, and the intermediate in series with a portion of switch for closing all the circuits for said 'electro-magnets to cause-the latter to-open said switches and insert said starting resistance, a main armature switch for closlng the rnain circuit through the mot-or armature and said starting resistance and at the same time short-circuiting the first electro-magnet of: the series, a mechanical device for retarding the closure of the first switch after being released by the first electro-magnet, and means for eiiecting the successive operswitches to cut out the starting resistance step by step.

.In testimony whereof I have signed my nan e to this specification in the presence of witnesses. ERNEST L. GALE, SB; lVitnessesz- ALFRED C. Bnonnr, ERNEST L. GALE, Jr.

Gavin a! this patent may be obtained -for'flve cents each, by adflreuing the Oommiuloner o! Pctentu. i Washington. D. 6-.

'each other, the first circuit being in (series the starting resistance, a

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