US653470A - Self-starter for electric motors. - Google Patents

Description

No. 653,470. Patented July [0, 1900.

H. H. CUTLER. SELF STARTER FOR ELECTRIC MOTORS.

(Application flied June 8, 1899.)

2 Sheets-Sheet I.

(No Model.)

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Patented July l0, I900.

2 Sheets-sheaf 2.

INV R TTORNQS.

H. H. CUTLER.

SELF STARTER FOR ELECTRIC MOTORS.

(Application filed June 8, 1899.)

(No Model.)

UNITED STATES PATE T (jrricn.

HENRY'H. CUTLER, OF CHICAGO, ILLINOIS.

SELF-STARTER FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 653,470, dated July 10, 1900.

Application filed June 8,1899. Serial No. 719,815- (No model.)

To all whom it may concern.-

Be it known that I, HENRY I-I. CUTLER, a citizen of the United States, residing at Ohicago, in the county of Cook and State of Illi nois, have invented a certain new and useful Improvement in Self-Starters for Electric Motors, of which the following is a full, clear, concise, and exact description, reference beinghad to the accompanying drawings, forming a part of this specification.

My invention relates to a self-starter for electric motors, my object being to provide means whereby the armature-resistance of the electric motor may be automatically removed from circuit during the starting of the motor.

In accordance with my invention I provide in circuit with the armature of the motor the usual starting-resistance and provide a plurality of eleotromagnets arranged to be successively operated to in turn remove portions of the starting-resistance from circuit, whereby the armature is permitted to start up gradually and build up in speed until normal operation results. In practice I divide the armature-resistance into sections and provide an electromagnet for controlling each of the several sections, the first electromagnet being arranged to become energized when the counter electromotive force of the armature has reached a certain value, to thereby cut out one of the sections of the resistance and lower the resistance to which the armaturecurrent is subjected, thuspermitting the speed of the armature to increase. When the counter electromotive force of the armature has reached a second prearranged value, a second electromagnet is energized to remove another section of the resistance, and so on, the electromagnets being thus successively energized to successively remove the sections of the armature-resistance from circuit until the desired speed has been obtained. The electromagnets are 'in practice connected in circuit, so that the first electromagnet when energized connects the succeeding electromagnet in circuit. I preferably provide a short circuit about the electromag- .-net to normally remove the same from operative position, which short circuit when opened includes the, electromagnet operatively in circuit. The electromagnets are usually made alike and adjusted to become energized when traversed by a current of a definite value, and by arranging each electro= magnet to connect the succeeding eleetro- T magnet in series with the same the resistance of the path is increased, thereby cutting down the current, and the succeedin g electromagnet remains in circuit unenergized until the rise of voltage brings the current up to the prearranged value.

I have employed the term electromagnet as broadly comprehending solenoids'and electrom'agnets, strictly so called.

I have illustrated my invention in the accompanying drawings, in which' 7 Figure 1 is a plan View of a self-starter embodying my invention. Fig. 2 is a sectional view thereof. Fig. 3 is a diagrammatic view illustrating the arrangements of the circuits. 1 1,

in the presentinstance as operated by means J of an arm 1?, connected with a float b, whereby the arm is raised when the float descends. A Weighted rocking lever 19 is pivoted at b upon the pivot of the arm I) and the switcharm a. tively to the arm I) is limited by the stops 6 b Upon the pivoted end of the lever 19 lugs b b are provided, adapted to engage and move switch-arm a. When the arm I) is raised, the weighted lever 17 is rocked toward the center of gravity thereof and is shifted beyond the vertical support, when the said lever falls to the left and the lug b engaging the arm a, carries the same into engagement with the terminal (0 thereby closing .the circuit. "When the float ascends, the arm b is moved downward, thereby throwing the weighted lever 17 to the right and carrying the switcharm a into engagement with the terminal a to open the motor-circuit.

The main 1 is connected with the terminal The movement of the lever b relaa and the switch-arm a is connected by conductor 3 with the terminal 0, between which and the terminal a the resistance d is connected, While to the terminals 0 c the resistance d is connected. The terminal 0 is connected by conductor 4 with one side of the armature e. The other side of the armature is connected by conductor 5 with the other main 2. The fieldcoil 6 is connected in shunt with the armature. From the terminal c a conductor 6 extends through electromagnet f, thence by conductor 7 to terminal 9, which is connected with terminal 9 by contact-plate g from the terminal g. Conductor 8 extends to conductor 5. A terminal 9 is connected with terminal g and normally through plate 9 with terminal g terminal 9 being connected by conductor 9 with one end of magnet f, while the other end of said magnet is connected with the end of magnet f. A conductor 10 extends from conductor 9 through winding f thence through winding f and conductor 11 to conductor 8. Upon the core f of the solenoid or magnet f is carried a contact-plate f adapted when the solenoid is raised to bridge together terminals c and 0 Upon the core f of magnetf contact-plate) is provided, adapted when the core is raised to connect together the terminals c and c.

In starting the switch-arm a is moved to terminal a and current from main 1 passes through the switch, conductor 3, resistancecoils d and d, conductor 1 through the armature'and to the opposite main 2. Circuit is thus closed through the armature and all of the armature-resistance. The shunt-path for the current around the armature is provided through conductor 6, magnetf, conductor 7,

contacts gg g, and conductor 8, and when the counter electromotive force of the armature has been built up to a prearranged value, according to the turns of the windings of the magnet f, said magnet is energized, drawing up core f and moving plate f against terminals c c to short-circuit resistance d, thereby cutting out a portion of the armature-re sistance and permitting the speed of the motor to further increase. The ascent of the core f moves plate 9 out of engagement with the terminals g g, and the shunt-path around the armature may now be traced over conductor 6, magnet f, magnet f, conductor 9, contacts g 9 and conductor 8. When the counter electromotive force of the armature is raised to a second prearranged value, magnet f is energized sufficiently to raise core f thereby moving plate f into contact with the terminals 0 c to short-circuit resistance d and move plate 9 out of contact with terminals g 9 The magnets ff are now in shunt with the armature, and as less current than that required to lift the cores in the first instance is sumcient to maintain the cores in their upper position windings f f are adapted to be connected in circuit with the windings f f in this position to serve as resistances to cut down the current through the magnets,and,further more, being in the form of windings they assist in holding the cores in their upper positions. The shunt-circuit may now be traced through conductor 6, windings ff, conductor 10, windings f f conduct-or 11, and conductor 8.

In Figs. 4, 5, and 6 I have illustrated a construction wherein three sections of resistance are provided in the armature. From the main 1 a conductor 12 extends to terminal h, and a conductor 13 extends from conductor 12 through the winding 70, thence by conductor 14 through the resistances 70 thence by conductor 15 through the contacts 70 70 of the controller-switch to the opposite main 2. The end of coil 62 is connected with terminals c c c and 0, while the opposite end of said coil is connected with terminal 0 the end of coil 61 with terminal 0 and the end of coil 61 with terminal 0. ContactplatesZ Z Z are arranged to engage the sev eral terminals, while contact-plate Z is arranged to engage the terminals 0 h. The plate Z is carried upon the core 70 of magnet 70, which core also carries plate Z adapted to engage terminals Z Z". Said core also carries plate m, normally in contact with terminals m 471?. plate land also a plate m engaging terminals m m The core 19 of magnet 19 carries plate Z and also plate m, engaging terminals m m and the core 7" of magnet 1' carries plate Z and also plate m engaging terminals m and m which are connected together by resistance m The opposite ends of winding 19 are connected with terminals m while the opposite ends of winding 7 are connected with the terminals m m and in the normal position these coils are short-circuited.

The terminal Z is connected by conductor 16' with the brush'e of the armature 6, while the other brush (2 is connected by conductor 17 with the end of resistance-coil d and also with terminal m Then the controlling-switch is operated to close together terminals k and 7c, current flows from main 1 over conductors 12 and 13 through magnet 7r, conductor 14, resistance '73, conductor 15, through the switch to terminal 2.

Magnet 7c is thus energized and attracts core thereby moving plate Z into engagement with the terminals h and c and moving plate Z into contact with terminals Z Z and moving plate m out of engagement With terminals m m The short circuit about resistance 75 is thus opened and resistance 7c is inserted in the circuit of magnet 71: to cut down the current therethrough, Current from main 1 now passes over conductor 12, terminal h, plate Z and terminal a and thence through the armature-resistance d (1 d conductor 17, and armature e to the op posite main Circuit is thus closed through all of the armature-resistances, After passing through the armature-resistance a portion of The core 0 of magnet 0 carries IIO the current passes through contacts m m m, thence through contacts m 017. m thence by conductor 18 through contacts m m m and conductor 19 through magnet 0, thence to terminal Z, contact-plate Z terminal Z and by conductor 16 to the opposite side of the circuit. The magnet 0 is thus connected in shunt-circuit With the armature e, and when the counter electroinotive force of the armature is built up to a prearranged value magnet 0 is energized, thereby attracting the.

core 0 and moving plate 1 into engagement with terminals 0 c to short-circuit resistance (1 and move plate on out of engagement with contacts m 072 thereby including in the sh untcircuit the winding 19. The shunt-circuit around the armature now includes contacts m m m, contacts 771 m m current then passing through magnet 19 and magnet o, and thence through contacts Z Z Z and conductor 16 to the other side of the line. When the counter electromotive force of the armature builds up to another prearranged value, the magnet 19 is energized, attracting the core 19 and moving plate Z into contact with terminals c c and moving plate m out of contact With terminals 772" m The second resistance (1 is thus short-circuited and removed from the armature-circuit, and the short circuit around the coil r is opened, so that the shuntcircuit around the armature now includes contacts m m m, magnet r, magnet p, and magnet o, the current then passing through contacts Z Z Z and conductor 16 to the opposite side of the circuit. When the counter electromotive force of the armature has built up to a third prearranged value, magnet r is energized, thereby attracting core 1" and moving plate Z into contact With terminals 0 c and moving plate m" out of contact with terminals m m. The shunt around the armature now includes contact m resistance m contact m, and magnets r, p, and 0, and the placing of the three magnets in series and the inclusion of the resistance m in circuit therewith cuts down the current to a value just sufficient to maintain the cores in the elevated position.

Having described my invention, What I claim as new, and desire to secure by Letters Patent, is-

1. In combination an electric motor and a resistance therefor, in series with the armature, a plurality of electromagnets adapted to be successively energized to remove the re sistance from circuit step by step, and means controlled by an electromagnet first to operatefor operatively including a succeeding electromagnet in circuit, substantially as described.

2. In combination, an electric motor and a resistance therefor, two or more electromagnets adapted to be successively energized to remove the resistance from circuit step by step, a short circuit around one of said electromagnets,and means controlled by the other electromagnet for opening said short circuit to include said short-circuited electromagnet operatively in circuit, substantially as described.

3. In combination, an electric motor and a resistance therefor, an'electromagnet adapted to be included in a parallel branch around the armature a second electromagnet, and means operated by said first electromagnet for including said second electromagnet in a parallel branch around the ar|nature,substantially as described.

4:. In combination, an electric motor and a resistance therefor, an electromagnet adapted to be included in a parallel branch around the armature, a second electromagnet, and means operated by said first electromagnet for including said second electromagnet in series with said first electromagnet in said parallel branch, substantially as described.

5. In combination, an electric motor and a resistance therefor, an electromagnet in a branch of definite resistance in parallel with the armature, a second electromagnet, and means operated by the first electromagnet for including the second electromagnet in parallel with the armature in a branch of greater resistance, substantially as described.

6. In combination, an electric motor and a resistance therefor, a plurality of electromag= nets adapted to be connected in parallel with the armature, and means operated by the respective electromagnets for including the succeeding electromagnet in a parallel path of increased resistance, substantially as de= scribed.

7. In combination, an electric motor and a resistance therefor, a plurality of electromagnets adjusted to be energized by the flow of a current of definite value, and means operated by the electromagnets for including the same in parallel paths of successivelyincreased resistance,substantially as described.

In Witness whereof I have hereunto subscribed my name in the presence of two witnesses.

HENRY- H. CUTLER. Witnesses:

W. CLYDE J onus, PERCY O. GILL.

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