Alfred H. Rzeppa

From Freepedia

Alfred H. Rzeppa was an engineer working at Ford who invented a version of constant velocity joint in 1926. He proposed an improved design in 1936.

It uses six balls, and an inner and outer race to provide constant velocity torque transfer regardless of the joint angle. The joint works something like a bevel gear with the balls bisecting the joint angle and functioning as the "teeth" to transmit torque.