Patent ID: 6621020
Filing Date: 2003-09-16
Classification: H01H

Abstract:
A breaking mechanism for a circuit breaker comprising:an operation handle, a fixed contact and a movable contact to be moved relative to the fixed contact, a toggle link connected to the operation handle to actuate the movable contact, a tripping device for moving the movable contact away from the fixed contact when a current flowing through the circuit breaker becomes excessive, an interrupting spring situated near the movable contact to urge the movable contact in a direction away from the fixed contact when the tripping device operates, a rotationally supported latch having a projecting circular surface at one end, said latch locking the toggle link to keep the interrupting spring in a force-stored state when the movable contact is closed, said latch being released and rotationally moved to unlock the toggle link to thereby open the movable contact using the force stored in the interrupting spring when the tripping device operates, and a rotationally supported latch receiver to engage and lock the latch to prevent a rotational movement of the latch, said latch receiver having an engaging portion engaging the projecting circular surface of the latch and having a recessed circular surface with a radius of curvature greater than that of the projecting circular surface of the latch.