Abstract: A handle operating mechanism adapted for use with an electric circuit breaker including a manually operable handle member, an operating axle having an elongated hole formed therein, a cylindrical member having a guide hole of predetermined formation provided therein, and a pin engaged with each of the above members. In a certain position, when the handle is moved in the axial direction of the operating axle, a hole is formed on the handle for cooperation with a locking member.

Abstract: A handle operating mechanism is provided to actuate an electric circuit breaker having a release lever and to interlock the electric circuit breaker and the door of a casing accommodating the circuit breaker. A manually operable handle is rotatably mounted on a case and is integrally coupled with a cam, disposed within the case, having a pin and a trapped portion. An actuating member which is engaged with the pin of the cam is linearly moved along a guide rod in response to rotation of the handle. One end of the guide rod contacts and slides along the circumference of the cam, the other end of the guide rod extending from the case to interlock with the door of the casing.