Inventors:
Christian V. Pellon - Norton MA
Nicholas V. Pellon - Norton MA
William J. Bentley - North Attleboro MA
Eric W. Morrison - Woonsocket RI
Assignee:
Texas Instruments Incorporated - Dallas TX
International Classification:
H01H 7330
US Classification:
337 82, 337 84, 337 66, 337 94, 200286
Abstract:
A thermally compensated circuit breaker has a movable contact assembly ( ) which mounts a movable electrical contact ( ) for movement between open and closed contacts positions with a stationary electrical contact ( ). The contacts are maintained in the closed circuits position by a latching mechanism ( ) which prevents opening of the contacts through an opening contacts force provided by a spring ( ). A current carrying trip arm ( ) deflects upon sufficient I R heating to transfer motion to the latch to separate the latch ( ) from the latch receiving catch ( ) to trip the circuit breaker. The trip arm ( ) is part of a pivotably mounted actuator assembly ( ) having a movable end portion spaced from the pivot disposed adjacent a motion transfer member ( ). A calibration screw ( ) is located so that the longitudinal axis is in line with a movable end portion of the actuator assembly and the motion transfer member. In one embodiment the head of the calibration screw is captured in a slot in the free end of a calibration base ( ) attached to the trip arm so that deflection of the trip arm directly transfers motion to the motion transfer member and in another embodiment the calibration screw head is captured in a slot in the free end of the trip arm so that a bowing deflection of the trip arm causes a calibration base ( ) to which it is attached at an end thereof to rotate with the calibration base directly transferring motion to the motion transfer member.