The connector includes a flanged clamping ring and an unflanged clamping ring. One ring is received within the other. Tightening screws tighten the connector by drawing the rings together in axial direction. Each ring has an inner and an outer surface. The inner surface of the outer ring and the outer...http://www.google.com/patents/US3957381?utm_source=gb-gplus-sharePatent US3957381 - Coaxial, double-cone, frictional hub-to-shaft connector
