Abstract: An infinitely variable gear ratio transmission includes plural cam followers driven to oscillate by a rotating cam. The oscillatory motion of the cam followers is combined through plural clutches to provide an output drive. The cam includes at least one surface formed to rotate the cam followers at a constant velocity when the cam rotates at a constant velocity, thereby permitting the output drive to be smooth. The cam is tapered from one end to the other to permit the gear ratio of the transmission to be varied in infinite increments by adjusting the position of the cam relative to the followers. Means for manually or automatically adjusting the gear ratio is provided. Increased gear ratios may be obtained by separating the physical location of the follower mounting shaft from the rotational axis of the follower arms. A universal joint, formed to uniformly transmit rotational velocity, is included to connect the inclined follower shafts to the output drive.