US 4,393,287 AGranted

Arc suppressing means for current limiting circuit breakers

AssigneeMatsushita Electric Works, Ltd.

InventorKunimitsu Nakano

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Abstract

Arc suppressing means for current limiting circuit breakers wherein an arc generated between both movable and fixed contacts by an excess current at the time of short-circuiting is magnetically driven by a member extending from the contact part of fixed contactor to an arc running plate in the right angle relation to the plate with a shortened time of arc's staying at the contact part and a shortened time of arc's traveling from the member to a deion grid along the running plate to quickly obtain an elevated arc voltage and to thereby effectively elevate current limiting effect.

Claims10

Dependent claims

An arc suppressing means for current limiting circuit breakers comprising a base made of an insulative material for mounting a circuit breaker;

a movable contactor pivoted to be rockable at one end having a movable contact;
means for manually operating said movable contactor;
means electrically connecting a load side terminal to the movable contactor;
means for tripping a contact closing position of the movable contactor in response to an excess short-circuiting current;
an arc suppressing chamber provided in said base so as to receive adjacent an end wall thereof at least said rockable end of the movable contactor;
a fixed contactor mounted to the base and including a part having a fixed contact positioned to contact with said movable contact in said contact closing position adjacent said one end wall of said arc suppressing chamber, said part of said fixed contactor extending substantially in a direction parallel to the movable contactor along the one end wall of the arc suppressing chamber;
a first arc running plate extended along a surface of the arc suppressing chamber which is perpendicular to said one end wall surface of the chamber and including means for electrically connecting said first arc running plate to said extended part of the fixed contactor;
a second arc running plate disposed substantially in parallel to said first arc running plate and electrically connected to the movable contactor;
and a deion grid disposed between said first and second arc running plates and arranged within the arc suppressing chamber with entrance ends of respective gaps directed to the one end wall of the arc suppressing chamber and with terminating the ends directed to the other end wall of the chamber, wherein said first arc running plate has a beginning end at said one end wall of the arc suppressing chamber, and said means for electrically connecting the first arc running plate to the fixed contactor is connected to said beginning end of the first arc running plate perpendicular to the first arc running plate and in substantially parallel relation to the movable contactor, said movable contact engaging said fixed contact adjacent the end of said connecting means that is remote from said beginning end of said first arc running plate to thereby render an excess short-circuiting current path on the side of the fixed contactor to be substantially maximum.

6 more elements

Dependencies are inferred from the claim text.

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Abstract

An arc suppressing means for current limiting circuit breakers comprising a base made of an insulative material for mounting a circuit breaker;

a movable contactor pivoted to be rockable at one end having a movable contact;
means for manually operating said movable contactor;
means electrically connecting a load side terminal to the movable contactor;
means for tripping a contact closing position of the movable contactor in response to an excess short-circuiting current;
an arc suppressing chamber provided in said base so as to receive adjacent an end wall thereof at least said rockable end of the movable contactor;
a fixed contactor mounted to the base and including a part having a fixed contact positioned to contact with said movable contact in said contact closing position adjacent said one end wall of said arc suppressing chamber, said part of said fixed contactor extending substantially in a direction parallel to the movable contactor along the one end wall of the arc suppressing chamber;
a first arc running plate extended along a surface of the arc suppressing chamber which is perpendicular to said one end wall surface of the chamber and including means for electrically connecting said first arc running plate to said extended part of the fixed contactor;
a second arc running plate disposed substantially in parallel to said first arc running plate and electrically connected to the movable contactor;
and a deion grid disposed between said first and second arc running plates and arranged within the arc suppressing chamber with entrance ends of respective gaps directed to the one end wall of the arc suppressing chamber and with terminating the ends directed to the other end wall of the chamber, wherein said first arc running plate has a beginning end at said one end wall of the arc suppressing chamber, and said means for electrically connecting the first arc running plate to the fixed contactor is connected to said beginning end of the first arc running plate perpendicular to the first arc running plate and in substantially parallel relation to the movable contactor, said movable contact engaging said fixed contact adjacent the end of said connecting means that is remote from said beginning end of said first arc running plate to thereby render an excess short-circuiting current path on the side of the fixed contactor to be substantially maximum.

6 more elements