Leader block rotary mechanism for cartridge magnetic tape device

A leader block rotary mechanism for a cartridge magnetic tape device, comprising:

• a leader block having a hook part for capturing a leader pin of a magnetic tape housed in a cartridge;
• a leader block picker for capturing the leader pin onto the hook part by holding and rotating the leader block set in a position for capturing the leader pin;
• a rotator lever integrally rotating with the leader block picker;
• a rotator cam for driving to rotate the rotator lever;
• and
• a loader cam gear for driving to rotate the rotator cam, wherein:
• the rotator cam, while comprising an over-rotation limiting device, is constantly energized to rotate in the direction where the leader pin is released from the hook part so as to give torque to the rotator lever in the release direction;
• the over-rotation limiting device transmits the torque of the rotator cam in the capture direction to the rotator lever and also allows rotation of the rotator cam while keeping the rotator lever, the leader block picker and the leader block at the rotation end position;
• and
• the loader cam gear, by forward rotation, rotates the rotator cam in the capture direction in resistance to the torque given to the rotator cam in the release direction.