An actuator for a medium voltage circuit breaker, the actuator comprising: - a closing shaft; and - a closing hook; wherein, the closing shaft has a longitudinal axis; wherein, the closing shaft comprises an interaction region at an interaction location along the longitudinal axis; wherein, the closing shaft is configured to rotate about the longitudinal axis; wherein, a cross section of the closing shaft at the interaction region comprises a first dimension extending from the longitudinal axis to a first part of the outer surface of the closing shaft at a first angular position; wherein, the cross section of the closing shaft at the interaction region comprises a second dimension extending from the longitudinal axis to a second part of the outer surface of the closing shaft at a second angular position; wherein, the cross section of the closing shaft at the interaction region comprises a third dimension extending from the longitudinal axis to a third part of the outer surface of the closing shaft at a third angular position; wherein, the first dimension is greater than the second dimension and the third dimension is greater than the first dimension; wherein, in a first state the closing shaft is configured to be at a first rotational position, wherein the closing hook is configured to be in contact with the interaction region such that the closing hook cannot rotate in a first rotational direction; wherein, in the first state the closing hook is configured to contact the interaction region of the closing shaft at the first part of the outer surface; wherein, in a second state the closing shaft is configured to be at a second rotational position, wherein the closing hook is configured to rotate in the first rotational direction past the interaction region of the closing shaft; wherein, in the second state an outer portion of the closing hook is configured to pass in proximity to the second part of the outer surface of the closing shaft in rotating in the first rotational direction past the interaction region of the closing shaft; wherein, the actuator is configured to transition from the first state to a third state, wherein the closing shaft is configured to rotate from the first rotational position to a third rotational position, wherein the closing hook is configured to be in contact with the interaction region such that the closing hook has been rotated in a second rotational direction opposite to the first rotational direction; and wherein, in the third state, when the closing shaft is configured to be in the third rotational position the closing hook is configured to contact the interaction region of the closing shaft at the third part of the outer surface. - a closing shaft; and - a closing hook; wherein, the closing shaft has a longitudinal axis; wherein, the closing shaft comprises an interaction region at an interaction location along the longitudinal axis; wherein, the closing shaft is configured to rotate about the longitudinal axis; wherein, a cross section of the closing shaft at the interaction region comprises a first dimension extending from the longitudinal axis to a first part of the outer surface of the closing shaft at a first angular position; wherein, the cross section of the closing shaft at the interaction region comprises a second dimension extending from the longitudinal axis to a second part of the outer surface of the closing shaft at a second angular position; wherein, the cross section of the closing shaft at the interaction region comprises a third dimension extending from the longitudinal axis to a third part of the outer surface of the closing shaft at a third angular position; wherein, the first dimension is greater than the second dimension and the third dimension is greater than the first dimension; wherein, in a first state the closing shaft is configured to be at a first rotational position, wherein the closing hook is configured to be in contact with the interaction region such that the closing hook cannot rotate in a first rotational direction; wherein, in the first state the closing hook is configured to contact the interaction region of the closing shaft at the first part of the outer surface; wherein, in a second state the closing shaft is configured to be at a second rotational position, wherein the closing hook is configured to rotate in the first rotational direction past the interaction region of the closing shaft; wherein, in the second state an outer portion of the closing hook is configured to pass in proximity to the second part of the outer surface of the closing shaft in rotating in the first rotational direction past the interaction region of the closing shaft; wherein, the actuator is configured to transition from the first state to a third state, wherein the closing shaft is configured to rotate from the first rotational position to a third rotational position, wherein the closing hook is configured to be in contact with the interaction region such that the closing hook has been rotated in a second rotational direction opposite to the first rotational direction; and wherein, in the third state, when the closing shaft is configured to be in the third rotational position the closing hook is configured to contact the interaction region of the closing shaft at the third part of the outer surface.