US1121574A - Circuit-interrupter. - Google Patents

Description

c. AALBORG. .y CIRCUIT INTERRUPTBR.

APPLICATION TILED 0G'1.7, 190B.

Patented Dec. 15, 1914 2 SHEETS-SHEET l.

i mvENToR WWNESSES i ATTORNEY G. AALBORG,

CIRCUIT INTEBRUPTEB.

APPLXUATON FILED 00T. 7. 1908,

hmmm Dm. Av15,1914,

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WlTNESSESI J I r.

o ers, and it has for rnnnssnvanra,

.SSGNOR BY MESNE SSIG MENTS, TO WESTINGHOSE ELECTRIC s MANUFACTURING COMPANY,

EAST PXTTSBURGH, PENNSYLVANIA, .L CGRPORATEON 0F PENNSYLVANIA.

Application led October 7, 1908.

To aZZ canoni it may concern L' Be it known that l, CHRISTIAN Annone, a citizen of the United States, and a resident of W'ilkiHSburg, in the county et' Allegheny end State of Pennsylvania, have invented a new and useful :improvement in Circuitinterrupters, of which the following is a speciication.,

`lilly invention relate:1 to circuit interruptits object to provide a device of the class above indicated that shall be specially adapted for interrupt-ing highn voltage alternating current circuits.

7lli/'ell known. types of oil swA ches have usually been employed for interrupting high-voltage circuits. rl`hese devices comprise,-in general, pairs of stationary contact members and movable bridging contact members which may be moved into and out of engagement'vvith the stationarj,T members, all of the Contact members beingr immersed in oil or in some other suitable insulating iluid. In such devices it is practically impossible to operate the movable contact members to interrupt the circuits in less than approximately a. twenty-fifth of a second, and since, at the frequencies usually employed, a complete cycle is accomplished in from one-sixtieth to one-twenty-ith oi a second, the current traversing 'the circuit would reach s maximum at least once. and probably twice, during the opening of the interrupter. Consequently, under the conditions indicated above, the interruptor must be capable of interruptingl the circuit when a maximum current is flowing in it.

According' to my present invention, l provide a plurality et stationary contact meinbers, a single movable contact-bearing mem.

ber which corresponds to the usual movable bridging member, referred to above, and a plurality' of cooperating movable contact members which are so arranged as to be successively disengaged from the stationary members when the interrupter is actuated to break' the circuit and the movable contactbearing member isseparated from the stat-ionary members. In this Way, a succession oit breaks is provided. in place of the single circuit interruption of the prior art, which is of advantage, for the following reasons: The breaks are connected in series so 'that the arc'must be sustained not only7 at the contact members first. separated, but addi- Specication of Letters Patent.

Patented Dec. i5, lilies. serial no. 456,520.

tional arcsin series with the first must be established at new points in the oil or other surrounding medium. v

.lt is a well known fact that when an arc is once established in oil or air, the insulating properties of 'the medium immediately around the are are impoverished and, consequently, a material advantage is gained by breaking the circuit established through the iirst are in another placrwhere the insulating properties or" the medium are unimpaired. v

ln addition to the t'oreqoing. by providing the succession of breaks referred to. the total tiine required to operate the movable member, which is approximately a twent`vfifth Aof a second, is divided into as many intervals as there are sets of stationary and movable contact members in the series. By utilizing'a considerable number of contact members, one of the breaks must obviously occur at or near the zero point in the alternatinpY current .vave, and, when this point is reached in the'succession of interruptions, the arc or arcs which may have been formed will immediately be quenched,

Figures l and Q of the accompanying drawings are elevations. at right angles to each other, of a circuit interruptor. constructed in accordance with my invention, the inclosing casing being` broken aivay to disclose the operating' parts. Fig. 3 is a diagrrrannnatic view of one complete cycle of an alternating current Wave.

Referring to the drawings, the device illustrated in Figs. l and 2 comprises a fluidcontaining tank or casino' l, a pair of stationarv terminal members 2 and 3 which project through the cover 4 of the tank or casing and are supported thereby.l a cross strip or support 5 of insulating material secured to the inner ends ot the terminal members in a horizontal plane,v a plurality of stationary Contact terminals 6 to 17 secured to said strips, a movable contact bearing member 18, a pluralitv of cooperating contact terminals 19 to 30 secured thereto, an operating mechanism 3l, and a vertical rod or shaft 32 'which connects the contact-bear ino member i8 to the operating' mechanism.

The stationary contact terminals 6 and 17 are respectivelv connected to the circuit conductors 33 which entend through bushings 34, and a cooperating pair of Contact teiminals 19 and 30 are securedto the movable contact-bearing member 18 and are adapted to be simultaneously separated from said Y stationary contact terminals G and 17. The

remainder of the stationary contact ter; minals. 7 to 15 are-'rigidly secured to the cross strip 5 of insulating material between the stationary contact terminals 6 and l17, and a series of movable contact terminals 2O to 29, which cooperate therewith, are resiliently supported by the movable contactbearing member 18.

Each of the movable terminals Q0 to 29 is provided `with a shank 35, which proyec-ts through a suitable hole 36 in the contactbearing member 18 and a nut 37, or other enlargement, is provided at the end of the shank in order to limit the independent movement between the Contact terminal .and the said member 18, a helical spring 38 being coiled about the shank between the contactl end of the terminal and the bottom of a y 'recess 39 in which it operates.

The movable contact terminals are arranged in a series in which the independent movement of each successive member is greater than that of the preceding member.

The stationaryand movable contact terminals are electrically connected so that the line current, which is normally established, when the'nterrupter is closed, from stationary contact terminal 6 through a shunt connection 40 and contact terminals 19 and 80 to the other stationary contact terminal 17, is completed back and forth through theentire series of contact terminals which are connected in pairs as mon as the movable contact terminals 19 and 30 are separated from the main stationary Contact terminals 6 and 17.

I deem Aitunnecessary to describetlie op.

erating and tripping mechanian of the circuit interrupter since any devices may be employed in this connection which may be .found suitable for performing the desired functions.

The operation of the device is as follows: Assumin that alternating' current is traversing t e circuit interrupter, which occupies its closed position, and that it is de'- sired to interrupt the circuit; if the current wave is reprented by the curve shown in Fig. 3 and the operating mechanism is actuated when the instantaneous current value is represented by the point m on the curve, the movable member of the interruptor will be completely separated electrically from the stationary member whenthe instantaneous current value is indicatedl by the point C. The movable contact terminals 19 and 30 will be first separated from the main contact terminals 6' and 17, an arc obviously being established on account of the instantaneouscurrent value which is assumed. A very short interval after the separa-tion of -tact terminals electrically the aforesaid contact terminals, contact terminl Q0 will be separated from Contact minal 7, the instantaneous curr r value l ing represented by point a. The successive breaks occurring at tlie points t, c, e, f, g,

It, z' and j on the curve, and, since c is at or close to the zero point on. the instantaneous current curve, the electric are which was established when the main contact minals 1were separated will be quenched always be interrupted under the tarorast able conditions.

Since various modifications in size and arrangement ot' parts may be eected the spirit and scope of my invention., l desire that only such limitations sball be iinposadas are indicated in the appended claims.

l claim as my invention:

1. In a circuit interrupter, the combination with a set of insulated stationary conconnected in pairs and disposed between the terminals of an interrupted service conductor. of a set of cooperating inslilated movable contact terminals also electrically connected 'in pairs in alternation with reference to tbe stationary contact terminals, and means for effecting successive disengagement o' said movable contact terminals from the stationary contact terminals to open thecircuit.

2. ln a circuit interrupter, the combination with a set of -insulated stationary contact terminals electrically connected in pairs and disposed between the terminals of an interrupted conductor of an alternating: eurrent circuit, a movable supporting member, and a set of coperating contact terminals independently supported by said member and electrically connected in pairs in alternation With reference to the stationary contact terminals, and means for effecting snccessive disengagement of the movably supported contact terminals fromtlie stationaryA contact terminals as said member is moved away from its circuit-closing pesition. l

3. ln a circuit interrupter, the combination with a set of stationary contact termi nals electrically connected in pairs. ot af set of movable Contact terminals electrically7 connected in pairs and so disposed that the contact terminals of each pair cooperate with stationary contact terminals of dil'er-l ent pairs, and means for causing said movable contact terminals to suoceively more eisesiit ieempter, vthe combina eepe'emg sets' of movable anni 14 'zemioals which are elecf ily eoimfected in pairs to -produce yf1.

.i successive' inter' uptions of a serviclucv3eswhen seperated y@3fm-l means "'W omplening e single low-resistance shunt ozmci all but-'the and terminals of velieri 'iheizitemr'upter is closed..

e, eiicuit i l".

containing tank o1' casl iieiefoxr, and steionary termieuelings projeesing lahrough and sup- -efwl by he cover, 'of e horlzontal strip ei insulating material supported -a ehe, easing from the inner ends of glie be hinge, a plurality of stationary con- 20 aimais secured to said bar and elecy connected in pairs, e movable conifzec-beei'ing member and :s Series of coperef'ig nioifable contact terminals also veleceeelly eemiected in pairs end liaving reengagement wle-l1l the stationery' conmmels es themterrupter-is opened.

silien; connecions member.

6. In e circuit interrup: the combinetion with e fluid-containing 'Lenk or casing, e cover therefor, bushings projecting through and supporsecl by the cover, of e ho izonal strip or bar of insulating material supported Within zhe casing from the inner ends of the bushings, a pli'iality ofstationary contec terminals secured to seid ber, a movable contest-bearing member and e series of coperating movable eonteet terminals resilienl seA cured to said contaet-beeiing member by unequal lost-motion connecions to pe'mit unequal iildependeniJ movements of said members.

In testimony whereof, have hereunto subscribed my neme this 21st clay of Sept.,

1908. CHRSTAN AALBRG. Witnesses:

EVM. P. LHOMMEDIEU, Bumm Hume.

o 'seid contact-bearing and stationery terminal'

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