Circuit breaker and shunt trip apparatus combined within single pole device

A shunt trip electric circuit breaker comprising, in combination:

• separable contacts;
• means for connecting said contacts in an electric distribution circuit;
• an operating mechanism manually operable for effecting overcenter snap-action of said contacts between separated and closed conditions;
• latchable means for enabling said operating means in a latched position and for effecting separation of said contacts independently of said operating means in an unlatched position;
• shape memory effect (SME) trip means indirectly heated by current flow in said distribution circuit for releasing said latchable means in response to a predetermined current flow in said distribution circuit;
• and
• means for selectively connecting said SME trip means in a control circuit for direct heating by current flow in said control circuit for selectively effecting release of said latchable means.

A shunt trip electric circuit breaker comprising, in combination:

• a stationary contact;
• a movable contact;
• means for connecting said contacts in an electric distribution circuit;
• an overcenter toggle drive spring for moving said movable contact into and out of engagement with said stationary contact;
• operating means for manually controlling operation of said drive spring for effecting selective toggling action of said movable contact into and out of engagement with said stationary contact;
• latchable means for enabling said operating means and said drive spring in a latched position and for effecting toggling action of said movable contact out of engagement with said stationary contact in an unlatched position;
• shape memory effect (SME) trip means responsive to current flow in said distribution circuit for releasing said latchable means;
• and
• means for selectively connecting said SME trip means in a control circuit for direct heating by current flow in said control circuit for selectively effecting release of said latchable means.