Patent ID: 7649433

Claim:
A circuit breaker, comprising: moving contacts immersed in oil; a cam mounted for movement upon movement of the contacts; a housing having a wall, the wall defining an enclosure shaped to contain the moving contacts and the oil, an inner cavity as part of the enclosure, and an outer cavity, proximate to the inner cavity, on the opposite side of the wall to the outer cavity; a push piece with a magnetic end and a cam follower end, the push piece mounted for movement within the inner cavity, the push piece mechanically coupled to the moving contacts; and an indicator piece with a magnetic end and a flag end, the indicator piece mounted for movement within the outer cavity, the indicator piece coupled by repulsive magnetic force to the push piece; such that movement of the contacts causes the cam to engage the cam follower of the push piece and thereby move the push piece which causes the flag end of the indicator piece to protrude from the outer cavity.