US902307A - Electric controlling device. - Google Patents

Description

l AH.,W.LB0NARD. y,

. ELECTRIC GONTROLLING. DEVICE.

, vj' v j t APPLICATION :FILED nu 1a 1905.

. E@ 6 www v1o ammi-SHEET s..

f- A H. W.,LE0NARD.- 4 ELECTRIC lGONTBOLLING DEVICE, APPLIOATIDH FILED HAY 13;v 1.905.

- i Y Patented Ofzi'` 27,' 1968.

1o sanita-Barni' -a.

H. W. LEONARD. ELECTRIC CONTBOLLING DEVICE.

APPLNAT Hm Y 13, 19' Patented oet. 27. 190s.

manana-annu '1.

. wvemoz l 11. W; L EoNARD.-- ELETBI C ONTROLLING DEVICE. Y

AP'PLIQATION Pimm MAY 13, 19.05.

Patented Oct. 27, 1908.

10 SHEETS-SHEET 9.

l Fly 26- V11. w. LEONARD. ELECTRIC OONTROLLING DEVICE.

www mf m13' 1?51. Patented Gern-227, 1.908.

10 SHEETS-SHEET 10.

wit/womb f//fMW- MW'- y trolling electric motors and other translating i vlowing may Ahere be referrer? to.

HARRY-WARD LEONARD, OF BRONXVILLE, NEW YORK.

ELECTRIC CONTRLLING DEVICE. I

Specification of Letters Patent.

Patented Oct. 27, 1908.

Application filed May 13, 1905. Serial No. 260,198.

To all whom it may concern.'

Be it known that LHRRY WAR'D LEONARD, citizen of the United States, residing at Bronxville, in the county of Westchester and State of New York,.have inventedcertain new and useful Improvements in Electric Controllin Devices, of which the following is a full, c ear, and exact specification.

My invention relates to devices for condevices, and especially to rheostatic controlling means provided with automatic protective devices.

The object of my invention is to improve these results, I embodyin combination various important4 features amon which the fol- I provide means for automatically protecting the mo-` tor armature, or other translating device,

"u on the occurrence of no-voltage or i i l imotor armatureor. field winding.

, ow volta e. In my referred form the no-voltage evice 1s an cetro-magnetic device responsive solely to the voltage to which the motor armature ma be sub] acted," and which is independent o the current in the Il also t p'ovide means .for automatically rotecting l is so functionally rela the motor armature' against a normally large currents. In my preferred form this .overload protective device is in the form of an electroymagnetic circuit breaker, so func.- tionally related to the circuit to be protected,

that the circuit breaker is alwa s in a pro.-

tective condition, regardless o the condition or position of other devices affecting the device to be protected. I also provide rheostatic means -for controlling the flow of current in the circuit. In my preferred form, the resistance controllin to the overload i device, that'a protective amount of resisti' .ance must be in the path of the circuit. to be' vestablished before the circuit can be closed by closing the overload device or otherwise. In my opened y the resistance controlli arm. In order to reduce the arc, which is ormed -when `the Lcircuit Vis opened either bytheresistance controlling arm or 4by the circuit breaker, to a miinmum amount and thus -practicall eliminate its destructive eect, I providee cient arc-ruptu-ring means. This 1s Apreferably an auxiliary, automatically, quick acting switch bv Which'the .circuit is arm or device,

greferred form, the circuit can he' finally broken and which acts quickly independently of the slowness of movement of the part breaking the circuit, suoli as the resistance controlling arm. I also piefen.

hand, whenlie p'erforms the acts necessary to close the circuit. This -will prevent thev operator from making an improper or 1nsuiiicient contact in closing the circuit. The circuit-connections of the armature and field of the motor are such as to always kee the armature and field windin in a close circuit so as to -avoid any etrimental effect due tothe inductive discharge of the field. The novoltage ma net is connected so that 1t 1s neverxsubject to any abnormally high electromotive force, such as might be due to field discharge. A

In certain cases, I provide means for obtaining control of the speed of a motor by both'armature and field controlling means which are so arranged that the motor cannot be started with an improperly weak field.

I preferably arrange the controlling means romplished by a single operating lever, or other movin device.

My invention will be understood by reference to the accompanying drawin'gs taken in connection with the following description.

Figure l is a -plan view of a panel or support showing the controlling and protective devices thereon; Fig. 2 is a similar view of a portion of Fig. 1 with some parts shownl in another position; Fig. 3 is a section on the line 3 3 of Fig. 1 with the overload arm ro,-

--inovedg Fig. 4 is a face view of one of the blow-out magnets; Fig. 5 is a sectional view thereof; Fig. 6 is a bottoni view of the end 15 l5 is a diagram of connections thereof;v Fior.

Q. A y f` .902,307

of the resistance controlling arm;.. Fig. 7 is an end view thereof with some parts broken away showing one of the shoes in section;

switch contacts; Fig. 13 is'a diagram of'v connections of Fig. Fig. 14 is a face view ,of a modified form of. controlling deviceadapted also to vary the field strength; Fig.

16 is a face view of a modification and Fig. 17 is a diagram of connections thereof; Fig. 18 is a face view of a controlling device in which tlie resistanoearm controls the inningv 20 switch-;F1g. 19 is fa face View ofanother form having additional protective devices;

.20 is a face view and also showing connections of a modied 'form having means for reversing the motor; Fig. f 21 l.is aA face 2v5 view and also showing connections vof an,-

other forni of reversing means; 22 is detail of the reversing switch; Fig); '23 isall .face view cfa-.modification inwhich the field is controlled and interlocked reversing 3Q means is provided;v Fig. a detail View 7- Fig. 25 is a diagram of connections'bf tle construction shown in Fig. 23;'FgL 26 isa.

face view also showing 'connecioris ofl a modiiicatlon having an mterlockedreversing '35 field rheostat; Fig. 27 is a similar view with a' modified vform of interlocking means; Figs. 28and 29 are detail views of Ia. 'modified' fo'rmnofrontact devices; 'Figl30- is a face view also showing connection? of a modified 40 form'eeor'trolling means adapted for `units 'of large capacity; and Fig. 31 is a detail view.

Referring to Fig. 1 the. controlling and protective devices are shown mounted upon a panell of insulating material, such as slate, and are thusall united into one complete unit. At the top of -the panel arel indicated thefjterminals for the motor and the y su ply /wire connections. Protective fuses o the in/closed type are indicated at 2. The supplyy wires are connected directly to these fuses, which act after a certain time interval and thus protect the motor and all parts onthe panehfrom overload currents 'and serveas a protective means in addition to the electromagnetic circuit breaker in case the latter should fail to act. A main switch 3 is connected in the main circuit for opening both poles of the supply circuit. bo The rheostat contacts of the motor starter hewn inthis figure are indicated at 4', and preferably mount 'the starting resistance in the back of the panel.

IThe movable starting arm is shown at 5, 6g is outer end moving over the cont-sets 4 In order to insure contact over a large area,

I provide'the-movable arm with a yieldabie. contact preferably divided into a plurality of parts, and each part is independently spring pressed.- The construction oi one' 70 form is shown in Figs.' G and 7.\ The contacting parts aie shown as a plurality of skate shoes 6, rectan ular in outline and comparatively lon and narrow, with curved ends and extenlug lengthwise across the'75 arm; that is, the shoes extend lengthwise in the directionV of movement. Each shoe is pressed aga-inst the resistance contacts by a spring T'at each end. Each spring is partly' inclosed in atubular. case '8, which has a 80 closed rounded outer end, and which end seats in considerably larger depression in the shoe. The s ring and its case extends int'o a considerablv larger hole drilled in the lower face ofthe arm, there being on'hole l85 for each spring. A iiexible'conductor 9is` Secured to `each shoe and also to the arm 5,`

giving direct electrical -connection between he parts. rl"he above construction secures excellent contact between the shoes and resistance contacts, gives uniform ressure and will permit the arts to be rea ily renewed or replaced.,A 4A oA by reason of this construction, the Contact skate can be raised oif in its path, such as a burned surface, due to 100 arcing, without breaking the circuit 'or seu .riously affecting the contact. This is quite important, not only as regards maintaining good "contact,but also as otherwise the retractile spring ofthe controller arm might `fail-to turn the arm to the initial position on account offriction or obstructions, due to imperfections in'the surface of the contacts.

I prefer to use copper for the contact skates,

and brass for the stationary contact seg` 110 ments which tendsto reduce abrasion of the u contact surfaces; The narrow long skate form of contact is very advantageous because it permits ofobtaining, upon a modern length of stationary contact segments, a number ofv independent, self alining, flexible contacts which are readily removableandl renewable.

The arm 5 is arranged to open the circuit when in the on' position on the insulating 120 strip or blind. contact 10. '.n order to obtain the quick break of the'circuit lin the presence of a strong magnetic field, I mount upon the panel adjacent to the initial resistance contact an ironclad ma et 11, shown more in 1*-25' circuit .as hereinafter explained.V Fixed to the face of the magnet and extending between the central core and a'projecting portion of the top part of the shell, is a nonmagneticcontact piece v13, preferably of copber. This is thus located in the path of an intense magnetic field from the end of the coreto thetop portion of the shell and any rupture of circuit taking place at the face of the contact piece will be in the presence of a strong magnetic field, giving an eiicient magnetic blow out. The contact piece 13 may have an extension 14: for connection of the circuit thereto, which may also be used in some cases for maintaining connection with the auxiliary contact.

The controlling arm carries the auxiliary contacty piece 15 which 1s movably mounted yupon the arm .and electrically connected thereto by a flexible connection. This contact piece in the present instance, is T'or Y tos the arm 5.

shaped in.- itsy general outline, the side extensions being curved and fitting loosely underthe-heads 16 of the pins-or screws fixed A wire 17 may be passed through the two heads 16 which will prevent them from turning and working loose and may alsoserve, in someA construct-ions, to re- .tain the contact piece orv f flipper 15 in place. spring 18 is inserted between the central portion of the auxiliary contact and f ali abutment on the arm so to constantly extensions to seat under the heads 16. If the force thefcontact outwardly and cause the two controlling arm is moved to oft' position, the auxiliary contactwill engage the contact 13 beforev contact is broken at the initial resistance contact. As the movement is continued, the contact .of the shoes 6 will be broken with the initial resistance contact,

- and the piece 15 willl-be deflected by engaging thesidecof contactl. Upon further movement, thefpiece l5y will move over the vface of the contactv 13 and-when 'the contact -is finally broken, the auxiliary contact 15 will 'be rapidly thrown away from `13 by the spring'l which always tends to return the auxiliary contact from a deflected osition.

The final rupture of the circuit wi l therefore vtake place -in a strong magnetic field and with a very quick actlon. Furthermore the parts which are subjected to wear or deterioration are readily replaceable in a simple manner.

In order to avoid the objectignable effects of a( slow or insuticient closing of the circuit, I providemeans for aquick make. A post or support is mounted on the base and carries a pivoted member 19 adjacent to the contact 13.v The member 19 is pressed by aj spring, as shown .inrFig 8, so that the outer end'is held in the path ofte projection or pin 20 onthe auxiliary `contact 15. Theunder surface4 of the member 19 is preferabl in? clined asshownf/Starting ,from the o position, as the arm is moved forward, the' contact 15 will engage and pass around the end of the member 19 and be deflected. When the disengagement takes place, the

piece 15 will be thrown rapidly and firmly against the contact 13 or its extension and close the circuit -with an ellicient contact. The main connection between the arm and.

Ainitial resistance contact will now be made before engagement of the auxiliary contacts is broken. The top of the projection 20 and the under face of the member' 19 are beveled in such a direction, as shown in Figs. 7 `and 8, that upon the return of the controlling arm, the beveled under face of the member 19 will engage the beveled top surface of the projection 20. This will cause the member 19 to be raised against the pressure of its spring out of the path of the projection 20; consequently on the return movement, the member 20 does not check the movement of the auxiliarycontact or interfere with the quick break movement thereof. The controlling arm 5 is thus provided with a quick make and quick break which acts very rapidly without reference to the slow movement of the arm.

In the nal position the no-voltage, or low voltage magnet 21, will retain the arm in place by attracting the armature 22 pivoted to the arm. In the inal-position the aux- `iliary contact 15 will engage the post 23 and cause the ield connections, as well as those of the magnet 21 to be connectedsacross the supply line independently of the armature resistance as will afterward be explained.

In addition to the. controlling arm 5, I have provided, an arm 24 pivoted on the same pivot with arm 5 and coupled thereto by a. spiral spring within the hub 25 on arm 24, which spring tends tol force the two arms together. `The arm 24 carries the main current from olnesupply line andacts as the',` overload circuit breaker in conjunction with the overload' coil 26. When the circuit is closed, thelatch 27 retains the arm in posi-- tion 'against the spring ressure, and lupon overload, the plunger ol3 coil. 26 rises and trips the latch to release the arm 2a. The latch is pivoted on a pin or post28 and actuated by a spring 29 encrclin the post so as to cause the latch to engage t e pin 30 on the underside of arm 24. The arm 24 carries a-switch blade 31. `From an extension ofthe frame of the magnet coil 26, project two posts 32. Each post carries two springs 33, 'and between the two springs on each post are held the two plates 34 having flaring edges to receive the bladel.- By this construction, I secure excellent Contact between. the parts, and even if they are somewhat out of alinement, the springs will per-1 mitcompensating movement of the parts y andthe direct sprin pressure -of the plates against the lswitch lade brings theparts tion `to the overload coil 26. An extension of arm 24 carries an auxiliary contact l5 similar to that carried by arm 5 and which acts in conjunction with a blow-out magnet ll in a manner similar to that above described. In this case, the auxiliary. quick break with magnetic blow-out will act to break the circuit; that is, when the arm is released, due to the overload current, contactl between the main contacts is first broken. The auxiliary contact l5 is deflected in the meanwhile and after the main contact is broken, the auxiliary contact will be broken with a quick action inthe presence of a strong magnetic field. Fig. 2 shows the position ofA the parts when thus breaking the'circuit,'and Fig. 1 shows the parts in their normal ruiming position.

It will be noted that when the circuit breaker is closed as shown in Fig. l, the auxiliary contact ,15 maintains connection with the auxiliary fixed contact. This is particularly desirable in those constructions in which the movement of the parts is only slight before the main contacts are disengaged, for if the contact 15 passed by the cooperating fixed contact, and out of engagement therewith, then the contact l5 must again engage the coperating contact within a slight movement ofthe parts and before the main contacts are disengaged. It is therefore preferable to extend the fixed auxiliarycontact as shown so that thisconnection is not broken when the circuit breaker is closed. This fixed auxiliary contact is provided with a curved or depressed portion as shown so that the end of the flipper will engage the same, and when the switch 'is moved to open the circuit, this curvedV or depressed portion will catch the eudof the ipper and deiect the same in the opposite direction, so that' the quick break action will take place. v

After the circuit is opened by the overload device, the overload switch is closed only by movement of the controlling arm 5. This is accomplished by means of arm 5 or a projection 'thereof engaging the arm 24 and' forcingit to the closed position. This necessitates the returning of the starting arm to its initial open circuit position. and in starting again, the circuit will be closed by the starting arm in .the manner above described. The starting arm will therefore always be in a protective position when the circuit is closed.

Fig. 9 shows the electrical connections of the form of controlling device shown in Figs. l to 8. The supply line is connected to the fuses 2 and current passes from them to the main switch 3. One line from switch 3 passes to the overload coil 26 and thence through the maincontacts to arm 24 when ply current is cut oli, the are closed'on themselvesthrough a starting `the latter is in operative position. Current also passes in another path to this arm from the same line, throughy the ccil oi the blow-outmagnet ll and auxiliary contacts.' The arm 5 is -in electrical connection with arm 2st. The other line from switch 3 passes to the armature A of the motor, and thence to the nal resistance Contact, then through the resistances to the coil of the magnetic blowout ll. Thus when the arm is moved to start the motor after the overload switch is closed, the circuit will first be closed across the -line by the quick make of the auxiliary contacts on arm 5 and continued movement of the arm will cut out the arma-v ture resistance and bring the motor up' to speed. The field winding F of the motor is shown as a shunt winding and Iis conf nected from one side of the supply line to the blow-out coil ll of the arm 5, or to the initial resistance contact. The circuit through the field from the supply line is therefore closed when the armature is connected to the supply line,.and when the suparmatule and field resistance. This provides a -path for the field discharge upon opening the supply circuit. The no-volti'rge4 magnet 2l is connected from one sidef. 1of' the supply line through a 95 Vresistance 361to the blow-out magnet l1, or

initial resistance contact. When the circuit is closed by arm 5,- the rio-voltage magnet will therefore be connected across the line in a circuit' independent of the armature or 10o field winding and will therefore act independently of such windings and can not be subjected to any dangerously high electromotive force due to field discharge voltage. With these connections, when the starting arm is in itszfinal position, the current to the field andgnosfvoltage windings would be obliged to'pass through the starting resistance, and in some cases I find it desirable to omit the starting-resistance from these circuits and obtain amore vdirect connection across the line. I accomplish this by connecting one terminal of the field and novoltage circuits to the post or .fixed contact 23. This is placed nearthe'linal position 115 of the starting arm, and when the latter is in the'inal position, the post 23 is engaged by the auxiliary contact 15, as shown in Figs.- 1 and 2. This will then give a direct connection from the 1ro-voltage circuits. A

In Fig. 9, I have shown means whereby the motor may be stopped from any convenient distant point, which may oftentimes be. desirable. This is accomplished in this instance by interrupting or shunting the current through the no-voltage magnet which will release the arm 5 and; cause the main circuit to be opened. A push button is indicated at 37 at one distant point for 130 arm 5 to the field and 120 breaking the 11o-voltage circuit and at 38 another L push button isindicated at some other desired point. `rThe latteris arranged to close a shunt around the no-voltage inagnet which would` cause'the same' to be deei'iergized and accomplish the same purpose las the interruption of the circuit by means 1 oi the push button 37. Any number of push buttons may be employed as the convenience of the operator requires."

Fig. 10 `shows a construction `which -permits the use of a large' numberof resistance steps and onefwhi'ch is'a'lso 'adaptedto carry Y heavy currents when 'the two sets 'of resistances are connected lin parallel. Two sets ofv resistance contacts are indicated at 4, 4, and the opposite ends of the controlling arm 39, carry the Contact shoes 6 which pass over the two setsy of resistance contacts. The auxiliary quick make and quick break means, together with magnetic blow-outJ is applied to the lower end of arm 39. In the form of construction shown in this figure, the arm 39 is not provided with a handle for movingvthe same, butis controllable by a second arm '40( The twov arms are pivoted on the same stud and are interlocked with each other so that there is a certain amount of play between them. The interlockingparts are shown enlarged in Fig. 11. The arm 40I is provided with projections 4l which extendr downward into the larger angular openings 42 in the arm 39', giving a certain angular play of arm with reference to the arm 39 without moving the latter. Consequently in starting, the arm 40 will be moved past arm 39 before the latter is moved, and when held by the no-voltage magnet 2l in the final position, the arm 40 will be in a position beyond arm 39. The

arm 40 is connected with the overload circuit breaker arm 24 by a spiral spring located in the hub 25 formed on the arm 24,

.which spring tendsl to i. force the circuit breaker arm and arm 40 toward each other. Considerable spring tension is therefore exerted on arm 40 when in its final position j and when released by the, no-voltage magv`net it starts into motion with the minimum friction and later willy strike against the arm 39 with a hammer blow by reasonlof the play of the parts and return the resistance arm to off position. This hammer blow action is 4particularly desirable for large units and where considerable force is needed to start the resistance arm.

When the overload circuit breaker is open. it is closed by manipulation of the arm 4G .which engages the overload arm to'force it 6.0'i1ito closed circuit position. In thus closing the circuit breaker, `the resistance arm 39 is necessarily moved to the off position by the movement otarm 40 and ay protective re sistance is tl'ierefoi'eal ways placed in circuit before the motor can be started.

The overload arm carries an auxiliary contact as above explained for securing a quick break and the coperating auxiliary fixed contact and means for obtaining a strong magnetic field .at the point of rupture of the circuit is also shown.

The action of the overload coil 26 to trip the latch 27 is similar to that explained with reference to Fig. 1. The construction of the main contacting parts is however, different. This construction is shown in Iiigs. l2 and 12a. The fixed main contact 43 is a laminated one fixed to the ypanel or support and has the edges of the lamin turned as shown so as to yield slightly when engaged by the main contact 44 carried by the overload arm 24. The contact 44 is carried bv two rods 45 which pass through arm 24 The electrical connections of the appara- I tus shown in Fig. 10 is shown vin Fig. 13. The connections are similar to some degree tofthose already described with reference to Fig. 9. It will be noted however, rthat in the present construction the two initial resistance contacts are connected together, and that the arm. 39 will connect the two sets of 'starting resistances in parallel, the current passing through 'the overload switch to arm r39 and then divide, passing through the starting resistance in parallel to the motor armature. The connections` may be such that the starting resistances will be in series for obtaining.T a higher resistance with a large number of steps. In such a lcase the opposite ends of the arm 39 will be insulated from each other and current will pass from, say the lower end of arm 39 through `the resistances connected to contacts 4',

thence to the upper end of arm 39, through the `resistances connected to contacts 4, and

then to the motor armature. The contacts 4. 4 will preferably be staggered with ret erence to each other so that only one resistance step will be cut out at a time.

Fig. 14 illustrates one form of my invention in whichzthe controlling device is ada ted not only for starting the motor but or regulating the field strength and armature resistance for the purpose of varying the speed. Fig. 15 shows the electrical connections. A set of armature resistance contacts is shown at 4 and the arm 5 makes electrical ,moved sutliciently to close the circuit at the connection therewith from the overload arm 24 as iii the construction previously described` Y The arm 5 is not spring pressed and i's v adapted to remain in any position placed. Then in. ott' position the circuit will be opened and the quick make and quick break devices and magnetic blow out are provided as shown. The arm is also provided with a handle for moving to any position desired, and thus include a varying amount of arma ture resistancefor starting or for varying the speed in some classes of Work where variation of speed in that manner is desirable. Means is also provided for varying the field strength by varying resistance of the field winding and the controlling arm 5 is adapted to insert resistance in the eld by the continued movement thereof after all armature resistance is cut out. Also the construction is such that the field is maintained at its full strength when any resistance is in the armature circuit. The-arm carries contacting parts 47, as indicated in Fig. l5, which are electrically connectedbut insulated from the arm. They contact with two sets of lixed contacts 4S, 49 Which are passed over by the( arm. The set of contacts 48 comprise an`initial contact of considerable lengthwhich is connected to the initial resistance contact of the armature resistance contacts 4, and the successive contactsli are each connected to successve contacts 4S. .The contacts 48, which are beyond the position of the arm when the last armature resistance step is cut out, are lield resistance contacts. f" The contacts 4f) comprise an ini tial contact; of considerable length extending from the oli position to the arm to the position occupied by the arm when the last armature resistance step is cut out, and additional contacts which are eld resistance contacts. Oneterminal of the field winding F is connected to the initial long contact 49.

Mounted on the pivot with arm 5 is the no-voltage arm 50. This is interloek'ed with the arm 5 to such an extent that. when thel arm 5 0 is moved to its iinal' position against the no-voltage magnet the arm 5 will be initial resistance contact, but when released from the no-voltage magnet 2l, arm 50 will strike against the arm 5 in whatever position the latter may be and force it to the otl" position. The construction of the overload device is similar to that described with rei!- erenee to Fig. l0, except that the extension carrying the auxiliary contact l5 is` short and at an angle to the arm 24. This arrangement permits the no-ifoltage arm and controlling arm 5 to have a large range of movement. The lio-voltage and circuit. breaker arms are spring pressed towards each other.

ln operation. ii the circuit breaker opens, it will be clos-cd by the operator by moving while the field resistance is varied.

the no-voltage arm to engage the controlling arm` 5 which in turn will move the circuit breaker to closed position, or the circuit breaker may be closed by movement of arm 5 directly. In either case the starting or controlling arm must be placed in a protective position before the motor can be again started. When starting, the arm 50 is moved against the no-voltave magnet and by reason of a shoulder on itsthub which engages a shoulder on arm 5', will, when nearing the no-voltage magnet, cause the arm 5' to move and establish the circuit by the quick make and by moving the skate shoes on to the initial resistance contact. Then the circuit is closed by the arm 5 the field of the motor will receive its full strength, current passing from oneline through the overload device and arm 5 to the initial armature resistance contact, thence to the initial contact 48, through contacts 47 to the initial contact 49, to thetield winding and other side of the line. Current will also pass from' the initial contact 49 through a resistance 3G and 11o-voltage magnet 2l to the other side of the line, this magnet being thus connected in a circuit independent of the motor windings. The arm 5 may now be freely moved by the operator. When the arm 5 is moved to cut out armature resistance, the resistance of the field circuit is unchanged, as current will pass from arm 5 to an armature resistance contact, thence to a corresponding Contact under the arm, then through contacts if? to the field. lience when any armature resistance is in circuit, the field is at its full strength. After the armature resistance is cut out. tui-ther movement ot the controlling arm will cause the contacts if to pass over the resistance contacts 5, 49 and gradually include resistance in the field circuit to cause the speed of the motor to increase. T he resistance contacts i8, 49 are preferably staggered so that one step oil' resistance will be inserted in the ticld circuit at a time. The tina] contact ai. is ot considerable length in this case in order to maintain thc connection in Fie. l5; means is shown tor conveniently stopping the motor from any desired point. such as by push buttons Il?. 38 which will interrupt or shunt. the current through the 11o-voltage magnet.

Fig. 1G shows another forni of my invention and Fig. 17 the electrical connections. In thisl construction the panel carries a circuit breaker which cooperates with the other controlling devices to protect the circuit and motor. hut in this case is mounted on the panel independently ot' the controlling and no-voltagc arm. ',lhe circuit breaker is doublc pole. each lswitch 5l. being capable oi independent operation. The overload coil 52 is connected" in series in the main circuit and upon overload is adapted to raise its plunger cease? and `engage the latches 53 to cause the release of'thespring pressed switches 51 and open both' sides Vot the circuit. rIhe circuit breaker is provided with auxiliary contacts 54 which may be' of the type having quick make and Vquickbreak with ymagnetic `blow out.r` 'The resistance contacts 'are'..arrauged in two sets 4, 4 which are passed over by the opposite ends'of the arm 5a. lThe vcircuit is closed and opened by the quick action of the 'auxiliary contact 15 carried on the lower' end of armA 5'? and which coperates with the devices as already described to give the desired action. In the final position, the arm is held by the 11o-voltage` mag net 21.' It also engages the two laminated contacts by means ofthe contact 56 car ried by the arm. .When engaged by the contact 56, the 'laminated contacts are adapted to yield and the contact 56 is also preferably springpressed outwardly, as explained with referencefto Fig. 12. j This construction not onlyl secures goodcontact, but the pressure exerted is of advantage in giving the arm a' quick start from its'position of rest, when released by the rio-voltage magnet. The necessity of an auxiliary arm, or other device, to give the arm 58L a lolon'T to start it may be overcome in some cases by this means.

Referring to Fig'. 17, it will be'seen that the current from one line, passes through `the overloadcoil 52' and through one switch `51 tothe arm When the circuit isclosed by this arm, the current will pass through the twosets of starting resistances in parallel to the motor armature and thence through the other 'switch V51 to the other line. Vlien the arm 5 closes the circuit, current also" passes through the field winding and novoltage'inagnet in independent paths. When the arm is in final position, all armature resistance'will be cut out andowing to the connections of contacts 55, current will pass directly from one switch 5l through contacts 55 and switch 56 to the armature. The path of the current through the arm 5 and its moving contacting parts istherefore avoided. The arm is provided with a spring 57 tending to return'yit'ftogthe ott position. in operating this f apparatus, the switches 51 should firstb'e closed and then arm 5 will be moved .from oii'l position to close thecircuiialf the arm 5a is moved to start the motor 'before Aboth switches 5l are olosed. the circuit will'not vbe conipleted, nor will the arm be held'by the no-voltage magnet.

The switches -51 should be', closed vone at a 4.time so in 'case an overload current should flow under Eany conditions when. the second one is closed, as might "be the case it the operator held arm 5a in running position, then the rst switch 51 will be automatically opened to `break the circ-uit.

In some forms of my invention, I provide il rheostat having no open circuit position,

but vprovide means for opening the circuit at another point, at which thc quick make and quick break, together with magnetic blow-out, is preferably used. I also control the opening of the circuit, and in sonic cases also the closing ot the circuit at this other point hyineans oft the rheostat armin various ways and either mechanically or elec-y trically. Figs. 1S and lii'illust-rate foi-nis ot' such construction.

Fig.A 18 shows a resistance controlling resistance ,contacts t and thus vary the amount of resistance in the circuit. The circuit is opened and closed however, by the niainswitch 58 pivoted at 59, and adapted 'to eigage the fixed contactv 60. Current passes from one side of the line through the switch 58 to contact 60, and thence through the resistance and motor armature A to the other side of the line. Current also passes from contact 6.6' through the eld winding F. The switch 58 carries the auxiliary contact 15 above described which cooperates with the auxiliary fixed contact 13 which is connected through the blow-ontcoil to the main contact 60. The member 19 is also provided to coperatewwith the pin 20 to give a quick make. Although in some con structions, the switch 58 may be moved slowly, and satisfactory results will he ohtained by reason of the action ot the auxiliary contacts, I have shown in the present case means for also giving the switch 58 rapid movement and to impart thereto ai hammer blow for throwing it. The arm 5b which controls the switch 58, carries an ex- 61 of a hammer'GlQpivoted at. 59. At. one end of the part 62 is a groove or slot 63, through which projects a pin 64 carried by the switch 58 or an' extension thereof. In another part of the hammer 62 is a second lgroove 65, through which projects a pin `66 fixed to the panel or base. A spring 67 connects the pin 66 to a central point at the opposite end of the hammer.

When the arm' 5* is moved to start themotor, the extension will engage one projection 61 and turn the hammer on lits pivot then act to throw. the. hai 'ifi i 'nerd quickly 'to strike the pin 64 .an d thus close; the main ,the oit position, the extensionfof Iarm `n n opening of the circuit at the resistance contected from detrimental arcing. Also lthe opening and closing movement Vot the main switch. .The -arrn niay'then 'be movd'asd I sired tovary thev res istari'ee.'i,l Whemeari I wil engage the other proj etioii`- 611-V and 4turn the hammer so that itwill strike f themin 6410-. open the switch58.; 'There is'tliereforeno switch is controlled by the resistance arm 1 switch or arm 5b adapted vvto pass over the tension which engages the projecting parte iio until the axial line of `:the .spring has passed the center of pivot 59,.When`tlie spring will tacts and the main switch is likewise proand the circuit can'only 'be closedwhen av protective amount of resistance is in the ciring 72b with either 72C or 72d.

Fig 1 9 shows a construction similar to Fig 18 with overload and no-voltage protectivedevices.- In this construction the resistance controlling arm 5 is spring pressed and is retained in closed position by the latch 27 which will be tripped to release the switch upon occurrence of overload. The

.overload switch 68 is provided with an auxiliary quick b reak Contact. 15 which acts as already explained to make the final break of ,the circuit in the presence of a magnetic field.

The current passes from one supply line through the overload coil 26 which acts to trip the latch 27 upon the occurrence of an abnormallylarge current, then passes through the overload switch to the main switch 58, through the resistance and motor armature to the other side of the line. The resistance arm is provided with an extension 69 which cooperates with an extension 7,0 ot' the overload switch G8 whereby t-he overload switch is closed by movement of the resistance arm to the off position. By reason of this con struction, the overload switch is closed at a time when a protective amount ot resistance is in circuit. Also the main switch 58 is closed only at a time when a protective amount oi'l resistance is in circuit.

Fig. 20 shows another form of my invention in which a reversing rheostat is shown. In this construction l prefer to interlock the vreversing controller in some manner with no voltage and overload protective devices. The rotation of the motor is reversed by reversing the armature current. 'lille controlling arm passes over armature resistance contacts 4lfor rotation in one direction and over contacts 4 for rotation in the opposite direction. he arm carries two insulated conducting portions 71, 71"?. the former connecting contacts el. with conducting strip T2, or contacts in with 72a, and the latter connectrThe controlling arm carries the auxiliary contact 15 which is electrically connect ed with the conducting portion 71, and when approaching or leaving the contacts 4 cooperates to give the quick make and quick break 1n the magnetic field. It acts similarly when approaching orI leaving the contacts 1a. The contact 15 is provided with a second pin 20 to cooperate with the member 19 to givethe quick make when approaching contacts 4a. 'Ihis pin is short and the member 19 is at a correspondingly low level, so that this pin will not engage the member 19 when moved in the opposite direction. Also the pin 2O is situated beyond the member 19 and therefore is not in its path. It will be understood that the top of pins 20, 20 is beveled in opposite directions since the direction of movement isopposite when the circuit is made in each case.

The overload and no-voltage protective means is shown mounted apart from the controlling arm. The overload switch 24. is retained in place by the latch 27 which is tripped by the plunger of overload coil 26. The switch 2/1carries the auxiliary contact l5 to cooperate with the auxiliary fixed contact 13 to give the quick break in the magnetic field. The no-voltage arm or switch 73 is pivoted and in electrical connection wire the overload switch 24. A spring 57 tends to press the two parts toward each other. The switch 73 carries an iron part 22 which will be attracted and held by the no-voltage magnet 21. When the switch is closed, it engages the fixed main contact 7 3. It is alsoprovided with the auxiliary contact devices for obtaining a quick break in a magnetic field. The overload switch is closed by turning the 11o-voltage switch in a left-handed direction and by interlocking means, the novoltage switch cannot be closed until the rheostat controlling arm is in ott position. The complete circuit will therefore always be closed by moving the rheostat arm from ofi position which necessarily includes a protective resistance in the circuit at the time of closing. In order to interlock the protective devices and the controlling arm, I provide a pivoted lever 74 one end of which is normally pressed by gravity or other pressure against the hub of switch. 73. This hub is notched at one point to receive the end of lever 73 when 'the switch is in the open position as sl own, and when in this position, the switch cannot be closed until the end of the lever is withdrawn from the notch. This open position ot' switch T3 will be taken if released from the no-voltage magnet, or in case the overload switch is opened and the switch 73 is operated to close the overload switch. When the resistance controlling arm is in the oit` position, the end of the arm will engage one end of the lever T4. and cause the opposite end to be withdrawn from the notch of the switch 73. The switch 73 is therefore free to be closed only when the controlling arm is in off position.

The connections will be understood from Fig. 20. Assuming that the starting arm is ofi'j"` osition, the overload switch will be ".fclosed' y; operating the no-voltage switch ,and then the 11o-voltage switch will be closed and held'by the magnet' 2l, which is in anl independent circuit across the line. If 'the v'controlling arniis now moved to the initial contact 4,' current will passi-'rom one sideof Vtheline through the novoltage and overload switchesoverload coil .26, througlrthe resistance to4 conductor 71,72 through the arma- .ture-IA, to 72C, 71, 72b, to the otherside of f `4the. The 'amount of resistance in the ture 'circuit will be varied by varying y v itiongof the arm. When the controllingarm is moved to engage contactsfi, curk rent-:will passvrom one side of the line, through the Lthroughthe protective devices,

i resistance to 71, 7 2, through the armature in the opposite direction, to 721,712 7 2b,to the j .otherside-of .the line. As the field connections `across thecircuit-remain unchanged, the rotation of the'motor is reversed. Of course, the same number of contacts 4a may Abefused for .the reverse as for the forward.

speeds, but a less number is shown, as usually Y v only a. lowspeed the 'reverse direction is "frequired.""f "f l 'l I 21.-.1ndicates a constructionwhereby a reversal ofthe motor is obtained, all parts aregpprotected from sparking, and protection 'to thecircuit vis always secured. The starting and yF thosey y described in connection with Fig. 1 as indicated.'- yIn coperation therewith is a doubl bladesl4 this instance, which coperate with four 'contacts 7 l when thrown in one dil, rection'ndgwith four contacts 74b when thlfwn 'inthe opposite direction. Of these contacts, oneof each,set,`namely 74, is provided. with shortercontact clips than the others as shown in Fig. 22, and these shorter clips are connectedin the circuit of the no! voltage magnet 21.

In operation, the switch bla`des 74 will be e thrown to engage say the upper set of contacts. The circuit breaker arm will be closed by means of the' resistance controlling arm and thecircuit will be nally closed by means ofA 'the resistance arm. Current will then passA "from one sideofv the line through the y eft-hanfd switch blade to the left-hand" conf 1 tact 74, through the overload coil 26, over- 5 third switchblade 74 from the l eft,.through -the armature Ayto fourth switch blade, to o L the' other 'side of the line. The field F is connected lacross the line from the initial lbad witch, .armv 5, armature resistance, to

lresistance]y contact to the other side of the liliiieglhe lI esistance arm will be held infilial`l o'siftio'n bythe magnet 21 whichis connecte across the'line in an independent circuit, currentpassing from the second switch il, blade, to the short contact 7 4, through magllf'net 21 and resistance to the other side of 'protective vdevices are similar toy e. throw switch having four switch" the line. New if it is desired to reverse ,the` motor, the double throw switch may 'be raised from contacts 74a t-o open the circuits. In doing this, contact with the short clip 7 4c will rst bebroken which will interrupt the no-voltage circuit and release the arm 5. The arm will be quickly thrown to oli position and open the circuit. Meanwhile the motor armature and field will form a closed circuit. through the starting resistance and anyA objectionable effect of inductive discharge of the field will be overcome: Consequently when thev double throw switch is 4openedto break the remaining contacts, the only circuit to be broken will be this closed Sq circuit of field and armature and as the current therein will be very slight or practically absent, there will be no sparking at the switch contacts. On tlirowing the double throw switch to engage the lower contacts, the connections will be similar to those above described except that the current through the armature will be reversed, which will reverse `the rotation of the armature. In raising the reversing switch from the lower contacts, the circuit of the 11o-voltage magnet will iirst be broken as above explained and no sparking takes place at the main switch contacts. It will. bc observed by this construction that all burning of the contacts of the knife blade switch 74 willI be avoided as this switch is closed only under conditions of open circuit and is opened onlyA while the insignificant field current is flow.-y inthrough i ig. 23 shows a construction 1n which means for reversing is provided and for varying the speed` by varying the' field strength as well'as the armatureresistance, all by means of a single operating device. 105 The construction of the overload and no- Voltage protective devices is similar to that explained with reference to Fig. 20, except that the overload switch carries an additional insulated switch blade 24"* withfaux- 110 iliary Contact protective devices so that when the circuit is opened on account of abnormal curre'nt,'.,both supply lines will be disconnected, there being two main 'breaks and two auxiliary breaks in series. The con- 115 trolling arm 7 'carries insulated conducting portions 75h, and 75?, (see Fig. 25 which make contact with the armature resistance contacts 76, 76 conducting strips 7 6?, 76", 76, 7 6, held resistance contacts 77, 120 .7 7 and conducting 'strips 7 7, 77". The controlling arm carries the auxiliary contact 15 which cooperates with the fixed contacts when turned in 'either direction from the 0E position. In order to produce Vthe quick 125 make, the top part or a projection 208,011 the li per 15- will engage themelnbers 19", 19h. lhstead o'having two pins bewlcd in opposite directions, as explained with reference to Fig. 20, thetop' part or projection 'i130 20a Y'is not beveled and coperaties With'hoth members 19a, 191. These have their under surfaces inclined as shown in Fig. 24, and in this construction the under surfaces of 19a, 19h, are oppositely inclined. Hence when turnedI to the left from oifrposition, the part 20a engages a surface which detlects the lflipper so as to give a quick malte, but when turned back in the opposite direction toward the off position, the flipper is not delected since the part 20 engages an inclined surface and the member 19 is rais.; t'rC- its path. The action` is similar nui.. re..- erence 4to the member 19h. The overload and no-voltage protective devices are interloclted mechanically With the reversing and controlling arni T5, so that the protective devices can he closed for starting up, only when the controlling arm is in ofi'A position and thus insures starting up proper conditions with a protective aint of resistance in the circuit. 'Ihevinterloclting means in this case is shown as a pivoted arm Ma having' one end engaging a notch in the hub ot the lio-voltage arin 73. Pivotally connected to the arm T4# is a rod 74?, which is in turn connected to the pivoted lever 74, This lever has one arin T4 extending into the path of the end of the controlling arin 7 5. A spring 7st" tends to keep the parts 741 and 74C in alinement and so tends to force the end ot lever 74 into the notch of the hub of ai-m73 'and also tends to force the arm Feld into the path of the end of arm 75. When in oil position, the controlling arm 75 will raise the part 74d and cause the end ot lever 'Tita tohe withdrawn from its notch. Under these conditions, the protective devices inay he closed, after which the circuit will he completed hy movement or the controlling arm T5. Hence, in starting up, the arin 75 niust lirst be returned to oli' position. lf we assume that the controlling arin is turned to the right so as to engage the first contact TG, current will pass from one supply lineV through the 11o-voltage and overload switches, overload coil to conducting part 76'?.y to strip 76a, throuolthe armature A 'to TO, iii the controllin through 75a, to the tli'st cont: t T6 h.. 'h the armature resistance to strip To, through the overload swi'.' ch hlade to the other supply line. The motor at this time `l f has its full licld strength. current passin L"oni one side ot' the line through the field Winding l" to the strip 77', into the controlling` i through conducting portion 75, to strip 77, 'to strip 7G" to the other side of the line. lVhen the arm is moved to cut out the armature resistance, the speed of the motor Will gradually increase. When all armature re sistanee is cut ont, the conducting 'portion 75h begins to pass over the contacts '.77 and gradually inserts re istance in 'the held circuit. rIhe weakening of the field in this manner gives further increase of motor speed. When turning the arni to reverse, all the eld resistance must be cutout and the armature resistance cut in. The armature circuit is then broken and protection or' the main contacts secured by means or' the anxiliary contacts with a quick hi'ealt iu a niagnelic lield. llhe field circuit is not new -hrolten or chan'ed. When the conti-(illino- D n arm is turned to engage the resistance contacts 7G'. the circuits are similar except'that the direction ot current through the arniatureri is reversed giving a reversed rotation of the motor.

Sometimes l use a reversing field rheostat to secure reversal of the motor. In such cases l prefer to mechanically interlock or electrically functionally relate the starter and reversing field rheostat so that the reversing` iield rheostat must he in ay condition corresponding to proper field strength ot the motor when the rter arm is nioved to close the circuit and start the motor. l `also prefer to arrange the rerersii'ig' field rheostat so that prior to revereii'igthe field connections, the-movement of the reversing field controlling arm Will cause the main circuit of the motor to be opened, for exan'iple by releasing the controllingr arm of the starting device. After reversing the field connections the construction is such in my preferred forni that the circuit can he again closed only when the field of proper strength.

Fig. 26 illustratesone such construction in which the interlocking means is niechanl ical and in Fig. 27 the parts are electrically interlocked so that the motor cannot be under a weakened field.

W rring to Fig. 2G, the controlling and protective devices are similar to those descrihed with reference to Fig. l. The controlling arm of the never-singv field rheostat consists two conducting parts 7S, 78 which pass over the iield resistance contacts 78a, 78D and the conducting strips 78, 781. The sha-ft of the field rheostat carries cani 79 having tivo depressed portions 791, 79h for the rod S0 to drop into When ,the rheostat arm engages either the initial contact 7B or initial contact 78h, or contacts adjacent thereto, may loe desired. The rod SO carries a yieldahle sect-ion 8()aL which project-s in the path el the extension 80D on the starting arm This extension 80h is so shaped that the arin 5 is free to move to the oft position, forcing the yieldable part 8Oa out of its path, het when in olf position can only be moved to close,A the circuit when the rod or part- 8()a is ont or" the path of extension 80. The portion 78 of the field rheostat arm is extended so that before the field circuit is broken, theextension Will act to raise the pivoted lever 8l and open the circuit of the no-voltage magnet 21 at 81.

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