Double-lever mechanism, trip actuator assembly and electrical switching apparatus employing the same

A double-lever mechanism is for the trip actuator of a circuit breaker having a housing, separable contacts and an operating member for opening and closing the contacts. A trip bar opens the separable contacts in response to a trip condition, such as an overcurrent condition. The trip actuator assembly is a self-contained unit including an actuation subassembly comprising the double-lever mechanism and a coil and a plunger housed within an enclosure. First and second trip levers of the double-lever mechanism are pivotally coupled to first and second ends of the enclosure, respectively. In response to the trip condition, the plunger extends, pivoting the first trip lever which engages and pivots the second trip lever in order to actuate the trip bar. The double-lever mechanism provides a mechanical advantage by reducing actuating forces and plunger travel.