Abstract: A switchable thermal circuit breaker (10) has an automatically resettable, current carrying thermostatic disc (14) cantilever mounted in a housing (12) and carries a movable contact (14b) into and out of electrical engagement with a stationary contact (14c). A disc coupling member (16) is pivotally mounted above the disc and has fingers (16e, 16f) to capture opposed sides of the disc so that the disc coupling member pivots concomitantly with movement of the disc. A radially extending blade (18c) of a pivot member is biased by a spring (18k) into engagement with a stop surface (16k) of the disc coupling member when the contacts are in the engaged position and is movable under the stop arm (16g) when the disc moves to the contacts disengaged position to prevent reengagement of the contacts.