Square D Company

Scott A Mickelson

Randall L Siebels

Ardean G Schill

Eugene W Wehr

Frank T Ehrenberger

Elizabeth A Billings

An electrical device, such as a circuit breaker, for interrupting the flow of current, which includes a stationary contact, a blade having a movable contact, a releasably latchable trip lever, a bimetal, and a magnetic armature. The movable contact is movable into and out of engagement with the stationary contact. The trip lever is releasable from a latched position for movement to a tripped position to cause separation of the stationary and movable contacts. The bimetal causes the release of the trip lever from the latched position by having the armature drawn a predetermined distance in response to a predetermined short circuit current. The trip lever is held in the latched positioned by a hardened latch having a minimal surface area, which is positioned near an opening located in the armature. When the predetermined short circuit current flows through the bimetal, the trip lever moves to the tripped position.

Latch for an electrical device

A reverse deflection prevention arrangement is provided for use in a circuit breaker for preventing a bimetal from bending in a direction opposite its normal thermal deflection. The reverse deflection prevention arrangement includes a tab portion extending from a yoke and a corresponding block member disposed on the inside surface of a circuit breaker cover. The tab portion engages the block member when the bimetal is forced to deflect in the direction opposite its normal deflection. An alternate embodiment of the reverse deflection prevention arrangement includes a reinforcement member secured to one end of the bimetal. The reinforcement member strengthens and supports the bimetal so that it is prevented from bending in the direction opposite its normal thermal deflection.

Growing community of inventors

Cedar Rapids, IA, United States of America

Scott A Mickelson