Actuator for rotating a rotary member

An apparatus mounted on a base in an automotive vehicle for actuating a throttle valve of said vehicle, comprising:

• a first magnetic rotary member rotatably mounted on said base about a rotational axis of said rotary member, said first magnetic rotary member having a cylindrical body portion which extends along said rotational axis, and having a first engaging portion which traces a peripheral locus about said rotational axis;
• a second magnetic rotary member rotatably mounted about said rotational axis, and having a second engaging portion engageable with said first engaging portion on the peripheral locus about said rotational axis, said first engaging portion being moved to be engageable with said second engaging portion when said first magnetic rotary member is rotated in one direction relative to said second magnetic rotary member, and said first engaging portion being moved to be away from said second engaging portion when said first magnetic rotary member is rotated in the opposite direction relative to said second magnetic rotary member;
• a solenoid concentrically mounted about said rotational axis in stationary relationship with said base, said solenoid including a bobbin defining therein a through hole and a coil wound around said bobbin for exciting said first and second magnetic rotary members to form a magnetic path therewith when said first and second engaging portions engage with each other, said cylindrical body portion of said first magnetic rotary member being received in the through hole of said bobbin;
• a rotating shaft secured to said second magnetic rotary member extending along said rotational axis, said cylindrical body portion of said first magnetic rotary member having a central aperture defined therein along a longitudinal axis of said cylindrical body portion, said central aperture receiving said rotating shaft;
• rotating means for rotating said first magnetic rotary member about said rotating shaft;
• and
• an output rotary member connected to said rotating shaft for activating said throttle valve in response to the rotation of said second magnetic rotary member when said first and second rotary member are engaged with each other to rotate together about said rotating shaft.