Patent ID: 7541901

Claim:
A circuit breaker for a doublebreak mechanism, comprising, a current interrupting section having a contact mechanism, said contact mechanism comprising first and second fixed contactors arranged in parallel and having fixed contacts, and a bridging movable contactor having an arm with movable contacts opposing the fixed contacts, and partition walls formed of organic polymer material and provided to stand along a path of switching movement of the movable contactor, said partition walls sandwiching each pair of the fixed contact and the movable contact to form a narrow arc extinguishing space between the partition walls, wherein said partition walls comprise outer partition walls formed outside the fixed contacts of the first and second fixed contactors and the movable contacts, and an inner partition wall situated between two pairs of the fixed contacts and the movable contacts, and the outer partition walls are composed of an organic polymer material that generates a greater amount of evaporating gas due to heat of arcing, and the inner partition wall is composed of an organic polymer material that generates an evaporating gas less than that formed by the outer partition walls.