Patent ID: 7594870

Claim:
A variable speed ratio transmission for transmitting rotational motion from an input to an output at a multiplicity of speed ratios within a predetermined range of speed ratios, said transmission comprising: a drive element having a spherical frictional engagement surface centered on a primary axis of the transmission; a carrier having at least one roller axle orbiting said primary transmission axis spaced from the spherical surface of the drive element by a predetermined distance; and a roller rotatably and slidably mounted on the roller axle so that the roller is free to rotate about and slide along the roller axle, wherein the roller axle is angled with respect to a tangent of the spherical engagement surface of the drive element so that the roller tends to slide axially along the roller axle toward the frictional engagement surface of the drive element to frictionally engage the engagement surface when a relative motion between the drive element and the carrier is in an engaging drive direction and to slide axially along the roller axle away from the frictional engagement surface of the drive element to disengage the engagement surface when the relative motion between the drive element and the carrier is in a disengaging drive direction opposite the engaging direction.