Texas Instruments Corporation

Nicholas V Pellon

Christian V Pellon

William J Bentley, Jr

Eric W Morrison

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.

Calibration structure for circuit breakers having bimetallic trip member

An electric circuit breaker ( ) has a toggle mechanism ( ) having two movable over center joints ( ) connected between a push-button ( ) and a movable contact mechanism ( ). When the push-button is depressed a first link rotates bringing the first movable over center joint ( ) across a center position represented by a first imaginary straight line ( ) to a stop surface ( ). A spring member ( ) provides a bias which acts on the second movable over center joint ( ) normally maintaining the second movable joint against the stop surface so that with the two movable over center joints biased against the stop surface the movable contact mechanism is moved to a closed contact position when the push-button is depressed. An overload responsive member transfers motion to the second movable over center joint ( ) upon the occurrence of a selected overload and moves the second over center joint across a center position represented by a second imaginary straight line ( ) allowing the contacts opening spring ( ) to move the movable contact mechanism to the open contacts position providing a trip free operation. The circuit breaker can be formed for a single phase or it can be formed for multiphase operation in which additional ganged phases have no toggle mechanism but do have separate ambient temperature compensated trip arms and overload responsive members which operate through the single toggle mechanism.

Electrical circuit breaker device

A circuit interrupter in the form of a circuit breaker (10) is shown having a movable contact (14a) which moves between contacts engaged and contacts disengaged position relative to a stationary contact (16a). An arc paddle (20) is mounted in a housing (12) for spring biased pivotal motion of an arc dissipating portion between a position out of alignment with the movable and stationary contacts and in engagement with the side of the movable contact when the contacts are in the contacts engaged position and a position in which the arc dissipating portion is in alignment with and in between the contacts when the contacts are in the contacts disengaged position to force arcs which occur between the contacts to extend their travel path and dissipate the arc in an improved shortened period of time. In an alternative embodiment the arc paddle (22) is generally U-shaped having two legs (22a, 22b) connected by a bight (22c). The paddle is pivotably mounted at the bight with one leg disposed in alignment with but beyond the contacts and the other leg disposed out of alignment with the contacts and closely adjacent the side of the movable contact when the contacts are in engagement. When the movable contact separates from the stationary contact, motion is transferred to the one leg causing the paddle to pivot with other leg moving into alignment with and in between the two contacts.

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Norton, MA, United States of America

Nicholas V Pellon