US1622630A - Arcing contact - Google Patents

Description

March 29 1927. 1,622,630

0. H. ESCHHOLZ ARCING CONTACT Filed Oct. 6. 1922 Fly Z WITNESSES: INVENTOR M OTTO/7. Esc/zho/Z ATTORNEY X Q. I

Patented Mar. 29,1927

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EEZWNSYLVMIA, ASSIGNOE 'IQ WESTINGHOUSE ELECTRIC $5 HANUFACTURZIHG GQMIAHY, A GUBPQPIATIGN GE PENNSYLVANIA.

arsenic contract I Application nice October 2, 1922. Serial No. 592%? My invention relates to circuit interrupters and particularly to means for effooting. the separation of two relatively movable contact members and extinguishing arcs that may be formed therebetween.

The object of my invention is to provide a pair of relatively movable contact members with means for preventing the reignition of an electric are after it has been exingaished.

Another object of my invention is to so arrange the relatively movable contact members that magnetic forces are set up therein to act as a blowout field -for arcs that may be formed therebetvveen.

Another object of my invention is to pro- 'vide contact members in which the rating may be increased, for given character of distress, by maintaining a comparatively short arc length with a maximum arc-terminal separation.

A "further object of my invention is to provide relatively movable contact members so designed that an are formed between two vertically disposed arcing tips will assume a horizontal position,

it is also an object of my invention provide contact members so arranged that the gas generated by an are at either contact member escapes at a desired angle to the direction of the arc stream, thereby'iacilitating the removal of the gas generated at the contacts and in the arc stream, as well as increasin the dielectric strength of the medium between the arcing tips against the reignition of the arc.

l have found, in practice, that the oilcircuit-breaker distress on rupturing alternating-current circuits is a function of the are energy. This is dependent upon the magnitudes of the short-circuit current and the arc voltage, the latter being subject control by, adequate design of arcing Circnitbreaker rating may be increased a given character of distress by inainta' a low arc voltage or a comparatively shor arc-terminal separation.

1.. my invention, the dielectric strength or" the medium surrounding the arcing tips during the arc-ruptnre period is increased bythe removal oi the arc gases "from the vicinity the arcing tips.

l igurel illustrates, in side elevation, the closed position of a pair oi arcing tips designed in accordance with my invention.

Fig. 2 illustrates, in side elevation, the

open position of the arcing tips, and the progressive positions awumed by the are stream are shown by means of dotted lines.

Fig. 3 illustrates, in side elevation, a portion of a contact inember provided with arcmg tips constructed in accordance with my mately straight horizontal contact portion 8, carved oortion 7 and anenlarged arcing tip 8. curved portion 3 is materially ereater than '1'" .L i I; Y Mi" 4 rip 9 J" K coa or too sa-non she arcing Lips a may be of solid construction or they be made hollow, as desired.

o be noted the extremi ies of 5 and 8 lie in approximately ior zontai plane. or low current members 1 and 2 may be cut 4, the cross section of movable m mber 2 is designed to present a curve to the liquid, hereby reducing the resistance of the liquid to moverem member.

Upon separation of the contact oortions and 6, are is formed, as at A (Fig. 2). The stream moves outwardly on the arcing; tips 5 8 because of the repulsive forces or the magnetic fields produced by the curienttraversing the arc stream and contact Inenioers. The progressive positionsor the are stream are shown by the dotted line positions in 5%.

The position oi the arc stream, upon its formation, is in a vertical plane but, during the progress e movement or the are stream along the curved portions 3 and 7, the plane becomes substantially horizontal when reaches the arcing tips 5 and 8. During this movement, the length of the arc stream increases somewhat and the magnetic impelling or blowout force decrease VJhen the are stream reaches the enlarged portions the arcing" tips 5 and 8, it ceases to increase in length because of the blowout effects, al-' though it may be somewhat extended by The radius of curvature of the convection currents and further arc-terminal separation. Because of the character of the arc-stream path, a relativel short arc-stream length has been maint'aine hence, a. low arc voltage, with the accompanying development of low are energy, obtains.

. The contour of the arcing-tips may be such as to providerelatively large masses,

thereby facilitating the cooling of the arc terminals, and, hence, preventing are reestablishment. It is obvious, that, under such conditions, a reduction of potential gradient may be secured between the arcing tips, thereby preventing breakdown of the dielectric separatingthem after the current has reached zero.

Because of the horizontal position of the arc stream, the arc gases rise upwardly from each arcing tip in a direction at a desired angle to the arc stream. The diversion of the gas from the path of the arc stream materially increases the strength of the dielectric between the contact members. Arc gases, when allowed to travel from one termine] to the other, as when the arc terminals are in substantially the same vertical plane,

facilitate the maintenance of the arc stream. By referenceto Fig. 3, it may be noted that contact members 11 and 12 become separated slightly in advance of the separationof the arcing tips because of the action of spring 13. Contact members 11 and 12 also interrupt the greater portion of the electrical current, members 5 and 8 serving as arcing tips for protecting the'main contact members.

A spring 14 may be employed to support the member'2. The positions of the arcing tip members with relation to the contact members 11 and 12 may be varied as desired, so long as the extremities of the arcing tips are in approximately the same horizontal plane, i

By combining the:e several'advantageous features in' my circuit interrupter, I have invented a device in which a relatively constant arc length of some predetermined minimum value is maintained with arc-terminal separation.

Various modifications made herein, spirit and scope of the invention, as defined by the accompanying claims.

I claim as my invention:

1. A method of extinguishing an electric and changes maybe are which consists in causing an arc stream to finally assume a substantially horizontal position from an initial vertical position and thus causing the gases generated by the electric arc to escape from the path of the arc stream at substantially a right angle.

a maximum without departing fromthe- 2. A circuit-interrupter comprising a pair of .parallel contact members and a curved arcing-tip member for, and extending at an angle to, each contact member, said arcing tips having different radii of curvature and 'the extremities of said arcing tips belng in approximately the same horizontal plane.

3. A circuit interruptercomprising a pair of parallel contact members and a curved arcing-tip member for, and extending at an angle to, each contact member, said arcingtip members having different radii of curvature and the extremities of the arcing tips being in approximately the same horizontal plane, the crossssectional area of thearcingtip members increasing outwardly from the contact members, whereby a large surface area is had at the extremities of the arcing tips resultin in a uniform potential gradient between sai tips.

4. A circuit interrupter comprising a pair of parallel contact members and a curved arcing-tip member secured at an angle to each contact member, said arcing tip members having different radii of curvature and the extremities of the arcing tips being in approximately the same horizontal plane, the cross-sectional area of the arcing-tip members increasing outwardly from the contact members, whereby a. large surface area and a large mass of material is had at the end of each arcing tip.

5. In a. circuit breaker, the combination with separable main. contact members, of curved arcing tips of difierent lengths projecting laterally from said members to a spaced and approximately parallel relation in which their extremities are in a plane substantially-parallel to the contact surfaces of thefmain members. when in their circuitclosin positions.

6. K circuit breaker comprising separable main contact members provided with laterally projecting curved arcing-tips of difapart in a plane substantially parallel to the .5

contact faces of the main members when in their circuit-closin positions. In testimony w ereof, I have hereunto subscribed my name this second day of October, 1922.

, orgg H. EsorinoLz

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