US1120709A - Automatic starter for electric motors. - Google Patents

Description

B. GALE, s3. AUTOIATIO STARTER FOB ELECTRIC MOTORS.

APPLIOATIOI FILED JUNE 14, 1807.

Patented Dec. 15,1911

gvwewtoz 4 1&4 J;

335% afloznua.

nuns runs. In. Luna. Iusamcm 0.1L

3mins- 1 i Fog-a ate;-a iiiictioimlea May 26,1905, seriaim. 262,313. Divided EW EnsnY, n cosereoii Specification of Letters :ItIOR r This Edi itemize item.

- J Sefia1"N 323,671. Divided and this application filed June 14, 1907. 'sefl -lln 373910}:

:Taall whomiit; may concern:

[Be it lqiownithat I, ERNEST L. GALE, Sin, 'aj citizen of the United States, residing st. tYonkers, in the county of Westchester and 'State,,'of--NeW York, have invented anew 'and :useful Improvement in Automatic ,Sta rters ,for Electric Motors, of which the followingisie, specification. 1 1

Iticu-larly-that used for starti'ngencl control- 3 ling electricwmptors." i V I .'lhis,applicationais a divis on of my (301 iReferring in series with the motor armature when the pending" application, Serial No; 323,671, tfiled 'June 27, 1906, for improvements in automatic starters for electric motors, iwh-ich it'self isfla division of my application 'filed "May 26,: 1905; Serial No. 262,318.

OnEofitheiobjeicts of the invention is the provision of automatic means for starting and controlling an, electric motor with maximnm-zefiiciency. I

Other; objects; f the invention s will appear hereinaftergathewnovel combinations of elementszbeingipoin'ted out in the appended claims.. 1 e v tobthebaccompanying draw ngs, Figure 1- represents diagrammatically one form of my invention in which a magnet switchiswused to close the controlling circuit;zandiFig;w2illustrates a modification in cuit for a main line main motor; circuit is closed. These resistances are proportloned' 1n the usual way to "preventtooflmuch'i current from; passing throughthe-.niotor iipon starting the same;- The mains l'd e'signated i by the signs I- end erewconnectedtlirectly to the'mo'tor arniw: the 1' aeonttct- 16?, 1 respectively,-

i nEig...l the field-J coil 9;".is' connected-to' the positive .I'haih tojthe'left of the moi011?aI'lHRlZIIIEZXIlaH tGFthG main armature cir- -uitibetweemtheziresistance '4 antlthe elecparallel Ltd the sectional starting resistance tro-mdgnetiosvvit '10. The field circuit is therefore viii? ashmrtu-to the nioto'r armature anlhthe startin'g resistance,

The i controllingecircuit is. connected i in land includes the solenoids 24 and 2 and a manual switch 11 which is arranged to open varying member 7,

i away from the contacts 5 armature when the 7 members 7 to be-"engagedrth b fixed contacts 5 d and close said contro ng circuit. The starting resistance my fheidivid'e'd" into'an'y number of sections with-r a 'correspondingelectromagnetic switch for each "section we said starting resistance'ma'y consist of oifly one section, in which case onlythe'electrm so magnetic switch comprising the solenoid-2 will be necessary. The" s'olen0 id-2** is ar ranged to act on its corecor plunger fito'*lift the contact maker, brid eQ meecit-resistance which 1's'connecte'c'l'there e5 t0! 50 as to disconnect br1 move:5awey-said resistance varying member kfromth'e 'cohtai(its 5 and 6, and thus insertthe resistancefl sh that it will be in series witli'the 'inotormus-r ture when the main circuit through the'lat ter is closed. Normally' themesistahe i -"is short-circuited through the low resistance" member 7 The solenoid 2 'acts'in' a similar manner to lift its plunger-18 midicontact maker or '1esistanee-ver-i11g "member r 7 1 andfi to insert the resistance 4?. in serieswithc-t e"- i n'otor main circnitthroiiglt the by then electromagnetic so condnctor l2 and the resistance fvarying-$ f\ letter is closed switch 10. The resistance-varyingmieniber 7 and 7 also act to short-.circ'ii itythe co'rr'e' spending resistances 44 "and 43 hen the?'re-- spective solenoids 2fand 12 domesaliiciently deenergized. I Arranged above the reslstance-veryln and fi c tively to the positive main at 3" of the motor 'armatureyfi'svviewe and to the solenoid of-ltheisw'ito solenoid 2 isrconnect of "the. manual switch-f1 Y 2* is connected to the; contact A 'fai' manual switch. These contztcts e;re"o -ar-;95 ranged that the pivoted' levex -23 whenT moved tothe: IeftLwi'll-engageifirit th contectrsm j and: then-the contact. 3 1:1 4 able-arrangement but is'n 6" the solenoid 2*, v f s' =-ie-*" sistance 21 is connected to 'the contacts 59 mg and 6 anc also in seriesewith th'e solenoid=' 52 of the elective-magneti switch 10, The screw 15 shown-in theifixed supportand starting i v. I 1,120,709

I 14 is for the urpose of limiting the upward movement '0 the core 8, so that when a series of solenoids and switches is used to' vary the sectionalresistances, said switches may be madeto operate successively in permitting their cores to drop.

When the single starting switch ll'is actuated toefi'ect the starting of the motor,

the lever 3 first comes into engagement with the stationary contact 3 which will' connect the magnets 2 and 2 across the normally open resistance circuit in which are the resistances 4 and a and the conmate 5 and 6. When the solenoid 2, re-

cei-ves current to lift its core followed by 2 lifting its core, the ,latters bridging'contact 7 will connect the two stationary con- "tacts 5, 6, and thereby short-circuit theresistance 21 which is in circuit with the mag- -net solenoid' 2 Now when the. switchlever 3 is moved'farther it comes into engagement with the stationary contact 3, and

' thus connects the magnet 2* across the line orbetween the and terminals. The 425 electro-magnetic switch 10 will then be op-.

erated, which results in the contacts 5 and 6 bein electrically connected by the'contact ma er 7 The switch 10 thus acts as an elect-ro-magnetic main line switch and 0 whenthe same is closed, the mam armature circuit including the armature 1, starting resistance andsthe'co'ntacts 5 and 6 and .contact maker T is closed. Current will therefore be admitted both "to the armature resistance and to the shunt field circuit 9'. e 4 v a The magnetsolenoids 2. and 2 will operate-to allow, their cores to drop successively or in the order mentioned, and to short-- circuit the sections of resistance 4? and 4' as the potentialfaci' oss the starting resistance circuit decreases. 'As soon as the magnet'solenoid 2 allows its core to drop,,it

will break the connection between the contacts 5 and 6 and thus reinsert the reslstance 21 in the circuit including the magnetsolenoid 2 This-will reduce thecurrent which passes through the solenoid 2 but not to a sufiicient extent for it to become'so defe'nergized as to allow its core to drop. This resistance 21 is-preferably so' -proportioned that it will not allow suflicient current to flow through the magnet solenoidfZ to enableit to liftits core when the latter I V '55 is down, but said resistance will allow sulfirapidly,

cient current to pass through said solenoid to hold the core up aiter it hasbeen lifted.

One otthe: advantages of this arrangement is that if the switcli ll should be closedthe main{ armature, circuit would not be closed until ,the starting resistance short-circuitshad been broken. The magnet solenoids 2? and 2 are arranged'in such a way that magnet 2 will'lift its core before magnet 2 does, in which case the starting resistance will always be increased to its maximum value before the solenoid 2 will lift the member 7 to close the main armature circuit. One of the methods for obtaining a successive operation of the sole- "noids 2 -and 2 and dropping their cores, is the employment of a d-iiierent number of' windings so as to have difierent numberj'oi" ampere turns. Fig. 1, thesolenoid 2 has a greater number of turns than the'solenoid 2 In such case the same amount of current flows through For instance, as shownin each of these magnet solenoids, and the solenoid 2 hav'1ng the greater number-oi alnpcre turns will hold up its core longer. Another: means for obtaining successive action of the solenoids in lifting or dropping their cores include the adjustable stop screws 15 mounted in fixed supports 14. These stop screws limit the upward .inovcm'cnt of the core'such thatlthcir upper positions inthe solenoids vary. For instance, if one core is projecting farther into its solenoid'th'an another core-into a corresponding solenoid, the

first core Willbe the first to operate. After attaining their upper posit-ions, those having the weaker fields will be the first to be permitted to descend. Y

If'the line circuit should v,idil While the starting switch 11 remainsclosed, the motor will be automatically protected and will not be injured if the line circuit shouldbe turned on again. In such event all three of the solenoids, 2 2 2 WVl1l againbe excited with current, but. the current flowing through the solenoid 2 will be limited by the resistance 21, and as this'current is not suffic ent to enable the solenoid -2 to' liftits core the-main line switch 10 will not be immediately closed. The solenoids 2 and 2" will lift their cores and thus change the starting resistance to its maximum volume..- The solenoid 2 will also cause the resistance 21 to be short-circuited so that suflicientcurrent call again pass through the solenoidv2 tocause the latter to liftits core and efi'ect the closure of they circuit including the armature and starting resistance after the latter has been inserted.

After the resistancesvarymg members i 7 and-7"have beenmoved-.-upwardly to positions indicated 'in Fig. 1, it may be said that they then occupy, their starting positions, said members normally connecting the contacts 5, 6 and 5B, 6, respectively.

izo

As's'oonas the motor starts up and increases in speed the potential-across the starting the motor has attained a I predetermined".

speed." In other words, the members-7 1nd -.7 normally short-circuit orcut out the s 2 were of sufficiently low resistance, the

I they bccupy p t ns t r star in po itio the members 7 and 7 to return in a retarded movement to their running positions after the main line switchflO is closed automatically. It will be noted; that after'the manual switch 11 has been operated, thb starting. resistance inserted, and the main line switch closed, the motor will start, and as-it increases in speed, less and less c ur-. rent will flow through'the solenoids 2 and 2 until gravity overcomes their upward pull to gradually movethe members? and 7 to their running positions successively in the order named. it should be further noted that it is not until the members .7, and

7 have been moved to their starting posi:

tions that the solenoid 2* can receive sufli cient current to effect the closure of the main armature circult. The amaln cllCult,

through the armature and, said members If the initial armature circuit including the armature only and the solenoids 2 1and armature would-start to rotate immediately when the lever 3 engaged the contact '3 inasmuch as the field circuit 9 would at this time be connected across the armature with the starting reslstance 4 43 m serles therewith. Preferably, however, the solenoids 2 and 2 are made of suflicientlyhigh re sistance to prevent the armature from starting until the mam armature circuit 1s closed.

As soon as the controlling circuit is closed the members 7 and 7 are moved quickly to their uppermost or intermediate positions, although the member 7 is moved up before the member 7 reaches its uppermost position. If the switch. 11 is movedofl both contacts 3* and 3? quickly the member 7 closes the main armature circuit .very

shortly, afterward. In factthe startinglop- I eration .is done very .quickly so that eizen 1 if thecont rolling circuit were of sufficiently low resistance to permit the motor to'operate, it'would not have time to start until the main armature eireuit is closed. 'Itis evident that solong as there is current in the controlling GlI'C111t .W l11 lQtll motor is speedingup, the plungers or cores' 1n the solenoids in the controlling eircuit Lwill.

move downwardly with a {retarded move- .ment. This. retarded movement shay be varied l-For instance,,if the plnngers are about the same length as the solenoids, the

.1: a m1-tted..to dropmore quickly, altho'ug'hsum. motor has-attained a predeterm neds'peed, I

the same solenoids 2 and 2 will permith P un es e in th i 4P- t Re 911.5%. th p u is m rb P81.

cessivel etardedybut-if the-upper ends l s iee yh f-w y' or he In Fig. 21

retaining circuit includi'nga. solenoid 12 for assisting the solenoid 2 in lifting the core 8 and maintainingxthe circuit-dosing device 10 inclosed p'ositionwso longas the switch lever, 3 is flIlBIlgagQmIllflWlth bhe contact 3 and the mains,are sufliciently en; J

ergi zed. Parallel with the electro-magnet solenoid 12 are connectedjresistjancei21 and' the electromagnet solenoidQtfof the eir cuiteclosing device 10. p a

l/Vhenthe switch QOHis clQsed, the field coil 9 will receive currentand all. theelectr'o-magnets will be energized. Only the whereupon the resistance .aryingf member mice 49 in the armaturelcir'cuitgI.Thelcon electro-magnet isolenoidQf2 however, ,re; ceives s'ufllclent current to f l1 ft 1ts core,

trolling icircuit 'is preferably of" .re-. 7

sistance so that the metas as s bastarted; by the current allowed topass thereth'rOughJ. As in Fig. 1,, so also .in Fig; 2, when the lever. 3 engages. the contact the, circuit will be closed including; the mmor afrmaf 'ture and the solenoid Qiiritseriejs"Twithjeach" other, and if this circuit were of sufiiciently lowfresistance' the motor, armature would start at this point, although the mai'narma ture' circuit 1s still openf The switch 10 may be placed; I t

"its,

in-the main line circuit, butdspreferably I connected-outside of tlie., shunt fieldterminals so that the shunt field will'no norvma'lly receiving currentfthat is t ag st .field circuit will not be consuming current: while the motor is-not beingloperated. 1

An additional contact; member T9". is see cured to the upper end o f'the core'8l in Fig; 2, so that when said core li'ftedcon tacts 5 and 6 will be electrically connected to short-circuit the resistance '21. Sufiicientcurrent can now flow through the electroits core 8E, together with nistnage "m mber 7 fastened to and insulated therefrom, so that the contacts 5 andB 'Willb'e electri-'- callyconnected with each otlieri The cir-.

.cuit including the motor'armat'ure andfthe startingresistance thus closedto allow sufiiclentcurrent to pass to start themotori noidv 12 the latter strength to hold said gcore "S in its' up'p POSItl OII- after current has"'*been' 's'hoz tir;

magnet solenoid 2 to caus .thesame'to lift i-bo cuitearrom the .electromagnet solenoid 2? 'sista by the, return of the resistance-Varying niem-' her; 7 I toits initial or running position. where the member")??? is again in engage inent'with the contacts 5 and '6 From the foregoing willhe seen-that; --iit-. erely requires theolosing of a-si'ngle switch to safely start themotor,:.and', .fur I 3.111 a selfstarter their-more, that the" motor will automatically combinati and" safely start up "again after being; stop V automatically protec'ts the-motor from ever- 1splied voluntarily 'atithe or *by the restahlishment in-which the motoris connected; that is,i circuit including a sourceof electric sup amply. and conductors "connected "to those marked and inthe drawings, usually through manual two-pole main line switch.

It v is f to he notedjthat each arrange will "of an operator,

not jonly is the current the armature Y sans mainarmat but for first completing a circuit through said t first-named;electro-magnetic switch :inse mg vc-ircuit veriedloy the operation of the m "controlled bythe co1 itrollingcircuit,

thmii- "thefcurrent in the controlling circui itselfi-s iedu'ced duringthe operation; that qth gnets' in the controlling circuit re-,

" arekcalled ap s to actuate 'switches'connec ed -thereto, and to practically 'formed'their work. automatically and ei'rtra switches or other auxiliary apparatus,

zero to after they hay This v is accomp Becaris'eof 'thisflfeature the magnets may a circ be made-smaller than they otherwise might,

andythe whole apparatusjsimpler and less expensive; I Obvious} make serious chang rangeincnt I of 1) arts witho ut departing f the. spirit and' scope' ofzmy invention,

rom

45,1 desire therefore not to be limited to the for preciseconstructionherein disclosed, I I WVhat I claim as new, and desire to have rotected by Letters Patent tates is? 80,- Inasturter l ina't'i0n" wan a armature 'ci member, an elect-roi'esponsi've device permanentlydconnected in series with the motor SSmrmature {for operating said member,

line switch, an electro-responsi e device for operati switch for successi of said electro-responsive d rders'pecified,

,2. In a star .noiiibinaticn with a star the armature circuit, of electro magnetic de, Vices permanently connected inserics with viri-h'motor armature for controlling said refor electric motors, the com starting resistance for the e'v'ices in the tcr for electric motors,

t ng resistance for ped -by. a "temporary interruption of the Sal. main line current supply. .I-consider again,

aQVa-luable' feature of'myfinventi01'i, ..as, it

load on starting, whether the current is sup-- and .a fieldcircuit permanently connected of current in a line: across- 11 a contain cent ma'xiinu-m current ajt the time they v s that this current is reduced; 1 cemloin e; per-- ,fance,f.o

lishedf switches for ,controllm "withouttheuse ofany ,L

thhse skilled 1' in theart may es in the .details'and arit" the United rcuitfiof a resistance-varying varying member, electroresponsive means 119; the switch, and a manual mote vely closing the circuits said nee, an'cle'ctro-inagnetic switch in the I armature circuit, and a manual s'witchmovable, mtopositions to successively close the circuits fol-"said devices and said switch, and. means "for preventing the operation of said switch until the controlling'devices have operated.

a near-0 thatportion' of tliearmature circuit mgthesaid armature and starting resistance. lv I a v 4." In a self-starter for electric motors, the combination with starting resistance, of an. ,electro-magnetic" switch or first inserting said resistance. and afterward cuttin it out again, an .electro-magnetic;switch or the ure circ'uit,'and an electric switch 4 ries with the motor armature} permanently and, then-the second-named electro-magnetic witch: 4 i 5. Ina selfstarter for electric motors,the':

ation with sectional starting f a plurality of electrormagnetici said. resistance, in, electro-magnetic maingine switch, 'and an electric switch for successively; closing first uit including the megnet'windings of controlling switches. and the motor j en a circuit for said armature in series, and th -said main line switch. 6. In alselfist rter for electric motors, the combination with starting resistance initially cut out, of an electric switch forconand trolling said resistance, an electro-magnet operating said switch, a main armature t switch, an electro-magnet for operat ing heflast-namedswitch, and a switch for: successively closing the circuits of said electro-ma'gnets, the circuit of'the magnet of the said controlling switch permanently including the motor armature. '7. In an'automaticstarter for electric inotors, the-combinationjwith a starting resistance forthe armaturecircuih-of a resistancecircm permanently connected in series with the r armature for automatically inserting startingresistance and thereafter autoagain, automatic ma'tically cutting it out.

' m for, closing the electroresponsive mechanls sivelyest'abli's'hing circuits to said electroreg the main armature clr'cuit aftersald starting rea member toiinsertsaidresistance, said'menrone ofthe mains.

and. said jelectroresponsive 8,,j Ina self+starter for. electric motors, the

eolnhinationfwith starting res istance, of a Ir ,remstance t'arying member,

v V 1I1' .electro'- mag et 'permanen y: connected- 1n series -w the motor armature .for moym d,

her returning automatically to "cut out said .re5i's'tance'ragain,"a;n e'lectro-magnetic main armature 'gcircuit switch, connections efi'ecttheclos'ure of the last-named switch afterthe resistancehas been inserted, and a switch twostationary; contacts in circuit with .saidelectromagnetand the magnet of the armature "circnit switch, and a device :for connectingsaid' contacts respectiyely to 9. In itself-starter -for'ele'ctric motors, the combination with sectional starting-resistance; of a pllir'ality of electric switches I ini-'. .tiallyjin ositIon cu'ttlng out said resistance,- g circuit in series with the armaa tro-magnet circuit, and connections comprising a resistance for effecting the operation of the main line magnet to close the main line switch onlyafter thestarting resistance has been'inserted. I I

10. In self-starters Tfor motors, the Com-1 bination with starting resistance, 'of a plu'-.

rality of switches connected'to said resistance, a controlling circuit' having therein a plurality of electro-mag'net's, one" for each'of said sw1tches,.an electro-magnetic main armature circuit switch, an additional resistancein circuit "with the electro-magnet of thelastmamed switch, and a switch adapted first to. close the controlling circuit 'in series with the motor armature and thenthe main line magnet circuitsuccessivel-v in the-order 1 two subscribing witnesses.

11. In :a self-starter for electric, motors, the combination with sectionalstarting .reslstance, of .a plurality of electric switches finitially'cutting out said starting resistance, i

a controlling circuitincluding a plurality of electro-magnets one for each of said switches and operating'succes'sively both to insert-- said resistance and cut it out again,-a- 1 nainline magnet, an additional resistance in ,cir-f cuit with said main linemagnet to prevent its operation initially, connections, effecting the cutting out of said "additional resist- 'ance after all the starting resistance is in-,, 1 serted, and a -fswitch for closing the com trolling circuit. to" efi'ect, flow of currentthrough the same and the armature in series initially, said last-named switch also clos ing the circuit of the main line magnet to.

effect the closureof the mainline switch to close the main armature circuit and place the" controlling circuit 7 across the starting resistance, the controlling" circuit-being short-circuited after the starting resistance has bpen cut. out ste -'by'step"asthe current through- .thejcontro ling clrcuiti decreases,

due to decrea'se ofpotential across said 's fi i' l n 12', 'e 'combination' er a elem-1c motor,

a 'stalyting iiesistance in the armature circuit, jelectro m ag'neticdevices controlling said resistance, an 'electromagneti'cswitch in the armature circuit, 'a-manualswitch movable. into positions-to successively close a circuit for said devices permanently in series with the motor 'armature and a circuit for said switch', a resistance in the magnet circuit of" said electromagnetic switch," and" 'meansoperated by one of said electromag netic' devices to short circuit said last named resistance and thereby permi't the operationof said electromagnetic switch.

In testimony-whereof, have sl'gned my name to this specification n the presenceof ERNEST Witnesses:

ALFRED C. Bncun'r," ERNEST .L. GALE, Jr.

Images