US919998A - Starting-rheostat. - Google Patents

Description

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(ff/M i@ raul. u; ZIMMER, OF s'cHENEcTADY, New YORK, AssIGNOR Y, .PANY, A CORPORATION OF NEW To all whom it may concern:

Bc itlrnown that To GENERAL ELECTRIC GOM- YORK.

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Naciones.

Speccation of Letters Patent.

vintermedi:.april 2?, 1909.

Application led December 26, 1967. Sera No. 408,146.

I, PAUL H. ZIMMER, a

",citizen `of the United States, residing at Schenectady, countyy of Schenectady, State or' New York, have'rinvented certain new und' useful Improvements l fica( ion.`

y character which cannot l careless handling of the operator,

This invention'relates to devices for controlling electri'cinotor circuits and has for its Object the provision of a device of this be destroyed by the und which is, at the same time, simple'in coifietruction in addition to being extremelyy i, reliable, eicient and durable.

lily invention relatesmore specifically to inotor" starting' rheostats.v In y devices of this character itis. common tov start the iu'otorbymoving thev lcontrolling arm over contuct'studs until the rio-voltage' magnet is rcucl1ed,=the inoto'r circuit` being closed upon x 4of overload conditions;'and a separate, in- .l dependently4 actuated switch, energized upon i .the initial movement ntlielcircuit. ,40

v so that the?. circuit will it is unnecessary I* be biased to the the first contact stud. With this arrangel ment, upon the failure of voltage, the arm returns to thestarting position and the circuit will be. opened upon the first stud,

Y(hereby causing arcing' and burning of thel Vcontact studs.

OneOfftheobjectsfofvmy invention is to provide, inA combination with an electroniagneticrswitch for closingthe main circuit, means for mechanically closingthe` same before thev resistance is varied; means for opening thejswitch upon the occurrence n the arm is left-in anyvother than the full running position'.

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ln,` the accompanying drawing, in whichl have shown my invention embodied in concrete form, Figurel Vis a. plan lView of my ,l device partly broken away showing the circuit connections, and Fig. 2 is a detail view of the operating handleand switch.

in y Starting- ,ltheostata of which the following is a specior by the' Y occurrence of abnormal circuitconditions, l5

.be engaged byV the plunger 27 Thisf'latter switch is arranged Referring to the drawings, represents an insulating base of slate or soapston'e provided With a series of contact studs 11 forining terininals'of starting Vresistance 12. A

`controlling arm 13 is pivoted at 14 so that its free end engages the contact studs 11, to Vary the resistance in the usual `way.v The arm is provided with-a handle 14' havingr a contacting plunger 15 arranged to recipro cate therein, and biased to an outward position by means of a spring 16. This plunger is adapted to engage a contact segment 17- arranged concentrically 'with the Ystuds 11. Contact between plunger and segment is inadewhen pressure is appliedto the plunger so as to overcome the tensionV of the spring 16 and force the end of the plungerv segment. .Whom however, 'the full running position is into engagement with the reached, -the plunger is forced upwardby meansl of an odset- 18, .which rholds .the

plunger andsegment in permanentcontact.

A switch arm 19 is pivoted concentrically with the arm 13 and is arranged to close the mainA circuit through carbon contactsl 20 and a laminatedlconiect 2l engaging the fired contact 22. The switch is biased or spring-pressed to an Open position by means of a spring 23, While a latch 24 pivoted at 25 is spring-pressed over vapin l26- on the switch arm, and locks the sainein plecef- The free end of the latch 2,4 is arranged to of the overload magnet 28 so that, as the plunger' rises tov trip the latch, Ait releases' the switch arm 19 to open the'inain 'circuiti A solenoid switch 29 is mounted conveniently u on the base and isA provided with two windings 30 und 31,v operating` upon the core or plunger 32, cari-ying at its lower end a laminated brush Contact 33 fixed contacts '3,4 raised.I This switch is 4also provided lwith carbon contacts 36 for taking the'inal break of the circuit. The winding 31 is energized through a iixed contact 37 arrangedto be engaged by contact 38, `mounted upon but arranged to, bridge the is inA its starting;V position. The arm 13 lis provided with a shoulder 39 adapted to .engage the arm 19 and force it to a closed osition when the arm 13 is .moved to the eft of its starting position on the first-of the studs 11. kMovement to the leftl is opposed and 35 when .the core is insulated from the arm 13, when the latter by a spring plunger 40 which returns the arm to the starting4 'osition. This plunger is connected to the circuit so as to -energize winding 31 when it is bridged to stud 37 by contact 38. 2

The arrangement of circuits and mode of operation are as follows; When it is desired to start the mtorhthe arm' 13 is moved to the' left in a counter-,clockwise direction. When the arm reaches the starting position, contact 37 is engaged by contact 38, and the winding 31, which is a lifting winding, is energized from the positive main through conductor 41, conductor 42, stud 37, plunger 40, conductor 43 andl back to line. At the same time, by forcingl the arm'13 to the left, the switch arm 19 is latched to a closed position, whereupon, the-main armaturecircuit is closed `at this switch. At the same time, the armature circuit'is closed' at the contacts 34 and 35 by the energizing. of the coil 31. As the arm is moved to cutout resistance, the circuit of winding 3.1 will be broken at contact 37, but the circuit of the holding coil 30 has been energized by the operator forcing the plunger 15 .into contact with the segment 17, so that the circuit will be kept closed at contacts 34 and 35.` If the operator should attempt to leave the arm in any position other than the full runningir position, the circuit of the winding 30 will immediatelyA open and thereby open the main circuit. When, however, the running position is reached, the offset 18 maintains the coil 30 energized. Upon the occurrence of an overload the core 27 will trip the 'latch 24 and allow the switch arm 19 to open the main circuit while the coil 30 acts as an underload coil to open thecircuit upon the failure of voltage. In this way the rheostat is protected against careless handling of the operator, since the arm must always be "brought to starting position before the circuitcan be closed, while' it cannot be left in lany other than the running position with the circuit closed.

While I have described my invention in connection with a particular mechanism and arrangement of circuits, it should be understood that I do not limit my invention in t-hese articulars, except in so far as it. is limited) by the scope of theclaims annexed hereto.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,-.

and means whereby one ot said switches is closed mechanically and the other electro@ magnetically uponan initial movement of said arm. l

3. A starting rheostat'comprising a resistance varying arm, a plurali'. of independently actuated switches in series therewith, means for closing said switches upon an initial movement of said arm, and means whereby said switches are opened upon the occurrence of no-voltage and overload conditions, respectively.

4. A starting rheostat comprising` a resistance varying arm, a plurality of independently actuated switches in series therewith, means whereby one of said switches is closed mechanically and the other electromagnetically upon an initial movement of said arm, and means whereby Isaid switches are opened upon the occurrence of no-Volt-age and overload conditions, respectively.

5. A starting rheostat comprising a resistance varying arm, a plurality of independently actuated switches in series therewith, means whereby said switches are closed by an initial movement of said arm, and a normally open circuit closing' device in connection with said arm l'or controlling one of said switches.

6. .l starting rheostat comprising a resistance varyingl arm. a plurality of independently actuated switches in series therewith, means whereby one of said switches is closed mechanically and the other electromagnetically upon an initial movement of said arm, and a normally open circuit closing device in connection with said arm for controlli-ng one ot said switches.

T. A starting rheostat comprising` a resistance varying` arm, a plurality of independently actuated switches iii-series therewith, means for closingsaid switches upon an initial movement of said arm, means whereby said switches are opened upon theoccurrence of 11o-voltage and overload conditions, respectively, and a normally open circuit closing device in connection with saidarm for controlling' one of said switches.

8. A`s`tartiug rheostat' comprising a resist-- ance varying arm, a switch in. series' therewith, means for mechanically closing said switch by a movement ol said a1'ma second switch i'n the armature circuit, and an electromao'n'etic device for closing the sante arranged to be energized upon the initial movement of said arm.

9. A startingn` rheost-at comprising a resistance varying arm, a switch in series therewith, means for mechanically closingl said switch by a movement of said arm, an Velec-I tromagnetic device for opening said switch upon the occurrence of overload conditions, 1.25 e second switch in thc armature circuit, and an elcctromamictic device responsive to no'- voltaeje conditions and arranged to be e11- ergizcd upon an initial movement of said arm for closing said switch.v

` 10.5 A startlingrlieostat comprising a resistance viirying atm, av switch in series theredevice. .p

1l'. A s'tartingrheostat comprising a rewith, means for mechanically. closing lsaid y switchV by -a movement of said arm, a second switch in thel armature circuitv, .an"e1ectro- .magnetic device for closing said switch arranged to/he energized upon an' initial movemeint of said. arin,` and 'a' normally o en circuit closing device'in connection with said arm for controlling said electromagnetic 'i sistance varying arm, a switch in series thereswitch and arranged 'to thel initial movement of said arm, and a norwith,l means for mechanically closing s aid switch by a; movement of said arm, anelectromngnetic device for opening said` switch upon the occurrence of overload conditions,-

nrmature circuit, an

a second switch inthe 'elect-romagnetlc device for closlng said be energized upon mally open circuit closing device in connecupon the occurrence of overload conditions,

of which is `tion withvsa-id arm for controlling said sec v ond electromagnetic device.l

1Q.l A starting rheosta't comprising a re 2 sistance varying arm, a switch in series there- With, means for mechanically closing said switch by a Vmovement of said arm, an electromagnetic devicefor opening said switch PAUL H. ZlhlMiEl Witnesses y j BENJAMIN B. HULL,

Humax Oniloln).

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