Circuit breaker with automatic catch to prevent rebound of blow open contact arm

Abstract From the Canadian patent

The outside poles of a three pole circuit breaker are each provided with a blow open latch which includes a latch hook having an open slot forming jaws pivotally mounted on the contact arm. A torsion spring biases the jaws to a cocked position in which they are aligned for engagement with a fixed stop member toward which the contact arm rotates as it blows open in response to the magnetic repulsion forces generated by a short circuit. As the jaws engage the stop member, the latch hook is rotated to mechanically latch the latch hook on the stop member thereby preventing rebound and reclosing of the contacts. A leaf spring mounted on the crossbar holds the latch hook in mechanical engagement …