US2253196A - Gas blast electric circuit breaker - Google Patents

Description

, 1941- w. E. PAUL GAS BLAST ELECTRIC CIRCUIT BREAKER Filed Sept. 28, 1940 Inventor: William E.Paul

. His Attorne Patented Aug. 19 1941 FFICE GAS nmsr anac'rarc cmourr BREAKER 7 William E. Paul, Schenectady, N. Y.,-assignor to General Electric New York Company, a corporation of Application September 28, I940, Serial No. 358,847 4 Claims. (Clzoo-14s) My invention relates to gas blast electric circuit breakers, and has for its principal object the provision of an improved gas blast circuit breaker having a large effective are cooling-area completely surrounding the arc for interrupting large power currents. A further object of my invention is an improved diverging radial blast circuit breaker arranged to force the arc into surrounding arc extinguishing structure.

My invention will be more fully set forth in the following description referring to the accompanying drawing, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of thisspeciflcation.

Referring to the drawing, Fig.1 is a partly diagrammatic illustration of an electric circuit breaker embodying the present invention including control means connected in an electric power circuit, Fig. 2 is an elevational sectional view of the gas blast circuit breaker shown in Fig. l'-, and Fig. 3 is an elevational sectio along the line 3-3 of Fig. 2.

Referring generally to Fig. 1, the gas blast circuit breaker indicated at l is connected through its contact structure, hereinafter described, in series with an electric powercircuit 2, the terminals of the breaker being indicated 7 at 3 and 4. When an overload or short circuit occurs on the power line, the contact structure air or gas pressure from a source indicated at! -10 spacers in the design illustrated may conveniently be formedas U-shape so as to extend also between the plates 19 along the vertical sides. The plates and spacers are provided with aligned apertures at the lower part of the casing to form a lateral passage 2| communicating with the nal view taken v I pressure supply conduit 5, the lateral passage 2i in turn communicating with vertical passages 22 formed at opposite ends of the breaker casing leading to the contact operating pistons l2 and The plates I! are also provided with aligned apertures 23 through which the contacts 9 and I0 operate. It will therefore be apparent that an are drawn between the contacts 0 and I0 2.5 will be completely surrounded by are extinguishin response to operation of the valve 6. The- -valve control can beaccomplished in any suitable manri r, such as by a current transformer l ,connecte to the, valve operating solenoid I. In addition to opening the contact structure, the

ing baiiies or barriers defining radially diverging venting passages 24.

The operation of the circuit breaker is as 3 follows: Let it be assumed that the breaker is in the closed circuit ppsition shown wherein the contacts are biased into engagement by their respective closing springs 25 and 26, and the. the control means at l and I call for a circuit opening operation. Immediately upon opening .of the valve i,-gas under pressure enters the gas under'pressure creates an arc'ex'tinguishing blast.

Referring more particularly to Fig. 2; the relatively movable contact structure comprises a pair of tubular contacts 9 and Ill arranged to engage in butt contact at H. Each contact is connected to an operating piston, the pistons i2. and I3 respectively being guided for longitudinal reciprocal movement in the cylinders I4 and; IS. The contacts are also provided with conducting extensions i6 and I1 including the breaker terminals 3 and 4 which are guided in the ends of the cylinders I4 and i5, respectively.

The circuit breaker housing comprises an insulating casing l8 that may be open at both lateral ends and also at the upper end. In the present instance the breaker casing, which is particularly designed-for high voltage, is open passages 2| and 22 in the circuit'breaker so as to act directly on the pistons i2 and I3. The pistons are thereupon projected at high speed into their cylinders causing rapid separation of 40 the contacts 3 and Ill. At the same time, gas

under pressure entering the ports 12' and i3 of the tubular contacts flows through the tubular contacts toward the point of contact'separation. The resulting gas blast from both contacts acts from behind the arc and serves to force it radially into the surrounding arc extinguishing structure defined by the plates is. a

In view of the fact that the arc must form slightly greater than that of tially in contact with are extinguishing structure immediately upon its formation. .Also, the'blast which mushrooms from the ends of the tubular contacts as illustrated by Fig. 3 necessarily traverses the arc regardless of its position between the contacts forcing it into the radially diverging passages 24. Stop and buffer means for the pistons l2 and I3 respectively are also preferably providedin the cylinders 14 and 15 comprising the spring enclosing sleeves l4 and I5 seated at rubber rings l4" and I5".

The contacts are now well separated and the blast continues as long as the valve 8 is held open in response to continuance of the fault. Although I have not in the interest of simplicity disclosed additional means for opening the circuit so that the arcing contacts can return to closed position after interruption of the arc since this forms no part of my present invention, it will be apparent that a disconnecting switch can be connected in series with the power line 2 as indicated at 21 so as to be opened after interruption of arcing By reason of the large arc cooling area extending radially from the arc in all directions, the large volume of highly heated arc gases accompanying heavy current interruptions, as well as the arc-itself, are effectively cooled by the large passage area of the radially diverging passages between the plates I9. Theradially diverging passages extending in all directions laterally of the are also aid in reducing back pressure to the gas blast by effectively dissipating the arc gases flowing into the extinguishing structure.

It should be understood that my invention, is not limited to specific details of construction and arrangement thereof herein illustrated, and that changes and modifications may occur to one skilled in the art without departing from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric circuit breaker of the gas blast type comprising relatively movable tubular contacts for directing a gas blast in opposite directions substantially axially of said contacts so as to meet and traverse the are at the point of contact separation, and arc extinguishing baiiie structure composed of insulating material arranged completely to surround the aforesaid arc and to form radially diverging blast ventin passages leading from the exhaust ends of said tubular contacts.

i 2. An electric circuit breaker of the gas blast type comprising relatively movable tubular contacts for directing a gas blast in opposite directions substantially axially of said contacts so as to mushroom from the coacting ends of said contacts and traverse the are at the point of contactseparation, and arc extinguishing insulating. plates having alined apertures for said contacts arranged in spaced relation transversely of said are so as completely to surround the aforesaid arc and to form radially diverging blast venting passages leading from the region of said arc.

3. An electric circuit breaker of the gas blast type comprising relatively movable tubular contacts including means for directing a gas blast in opposite directions substantially axially of said contacts so as to meet and traverse the are at the point of contact separation, means for causing separation of said contacts by and in accordance with said gas blast, and are extinguishing structure including spaced insulating plates having alined apertures for said contacts arranged completely to surround the aforesaid arc and to form radially diverging blast venting passages leading from the region of said arc.

4. An electric circuit breaker of the gas blast type comprising relatively movable tubular contacts for'directing a gas blast in opposite threetions substantially axially of said contacts so as to mushroom from the contact-making ends of said tubular contacts and traverse the are at the point of contact separation, arc extinguishing insulating structure through which said tubular contacts operate in close proximity arranged completely to surround the aforesaid arc and to form a plurality of spaced radially diverging blast venting passages leading from the contact passages, means for connecting both said tubular contacts with a source of blast pressure, and piston means for causing separation of said contacts in response to blast pressure.

WILLIAM E. PAUL.

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