Abstract: A gyroscopic type, infinitely variable, fully automatic, mechanical power transmission, speed changer, or torque converter capable of transmitting a wide range of output torques and automatically performing at the most appropriate input-to-output rotational speed ratio for the most efficient transmission of power in any given situation.In its most basic design, it comprises a rotatable main frame, two identical and separate sub-frame members which are rotatably mounted within the main frame, four identical gyroscopic-type rotors which are coaxially spin-mounted in pairs within the sub-frames, and two stators, one for each sub-frame, with each stator circumferentially positioned around the sub-frame member.Operationally, the rotors have radii of gyrations which are varied automatically in predetermined sequence in concert with the rotation of their sub-frame members.