Abstract: A circuit breaker (10) is shown having a movable electrical contact (36) adapted to move into and out of engagement with a stationary electrical contact (38, 40). A current carrying thermostatic trip member (42) has a portion movable in response to changes in temperature with a motion transfer member (46) transferring the motion to latch/catch mechanism (20, 24, 30, 32). The catch portion (30, 32) comprises a generally U-shaped adjustment element (30) formed of thermostatic material whose legs are fixed to the base (32a) of a catch member (32) which in turn is pivotably mounted in the casing of the circuit breaker. The bight (30c) of the adjustment element is free to move in response to temperature changes relative to the catch member. Overcurrent will cause the thermostatic trip member to transfer motion to the bight of the adjustment element causing the adjustment element and catch member to pivot and release a latch to thereby open the circuit breaker.
Type:
Grant
Filed:
October 25, 1999
Date of Patent:
May 8, 2001
Assignee:
Texas Instruments Incorporated
Inventors:
Michael J. Lavado, Nathaniel Wicks, Peter G. Berg
Abstract: In the manufacture of a circuit breaker comprising a cover having a snap action blade attached thereto, with a movable contact mounted on the snap action blade, the optimum position of the movable contact with respect to a preselected locus is first determined and the movable contact is adjusted to the optimum position prior to closure of the circuit breaker. The optimum position prevents frying of the circuit breaker during operation.
Abstract: An over-temperature control for a thermostat uses an electrical contact actuator of a memory metal having an ability to change its physical configuration at a transition temperature to a "memory" shape. The contact actuator is arranged to bear against a cantilevered leaf spring having electrical contacts at a free end of the spring while the other fixed end of the spring is connected to complete an electrical circuit through the spring. The spring is also actuated by a bi-metallic element to produce a normal temperature responsive operation of the thermostat. The memory material actuator is arranged to provide a flexing of the spring cantilever to move the free end contact between a first and a second electrical terminal when the memory material is exposed to a transition temperature allowing the actuator to assume its "memory" shape.
Abstract: A temperature responsive switching device is provided in which a pair of spaced bimetallic electrical switching arms each are anchored to opposite sides of a mounting block for attachment to the respective power leads of an electrical supply circuit. The free end of the spaced bimetallic arms each contain an electrical contact. A central arm is disposed between the contacts and has a neutral contact mounted thereon such that each of the contacts on the bimetallic arm is biased at room temperature into contact with the central electrical contact. Upon one of the bimetallic arms experiencing a predetermined temperature the circuit is broken by deflection of the bimetallic arm. Upon the switch experiencing a second predetermined but higher temperature, the second bimetallic arm is deflected to open the circuit.