Patent ID: 6720856
Filing Date: 2004-04-13
Classification: H01H

Abstract:
A circuit breaker comprisinga housing, a stationary electrical contact mounted in the housing, a movable contact assembly having a movable electrical contact movable between open and closed contacts positions with the stationary electrical contact, a spring member for applying a contacts opening force to the movable electrical contact, a latching mechanism for maintaining the movable electrical contact in the closed contacts position, a motion transfer member for transferring motion to the latching mechanism to unlatch the movable electrical contact and allow the movable electrical contact to move to the contacts open position under the influence of the contacts opening force, an actuator assembly pivotably mounted in the housing, the actuator assembly comprising an elongated bimetallic trip arm and a calibration base each having first and second ends, the first end of the trip arm fixedly attached to the first end of the calibration base, a calibration screw mounted in the housing generally in alignment with the motion transfer member, the calibration screw having a head in engagement with the actuator assembly and, upon rotation of the calibration screw, being movable toward and away from the motion transfer member to pivot the actuator assembly to a selected position relative to the motion transfer member, current carrying flexible members electrically connected to spaced apart portions of the bimetallic trip arm forming part of a current path in the circuit breaker, the bimetallic trip arm being deflectable upon a selected overload so that a portion of the overload trip assembly moves and transfers motion through the motion transfer member to unlatch the latching mechanism allowing the contacts opening force to move the movable electrical contact to the open contacts position.