Hays patents issued by U. S. Patent Office, 1936-1950 [originals, bearing Patent Office seal]
File — Box: 5, Folder: 9.1
General
Pitch Differential Means for Lifting Propellers (June 23, 1936).
Rotating Blade Means for Aircraft (September 29, 1936).
Differential Mechanisms for Rotative Wing Aircraft (July 13, 1937).
Hinge Differentials for Rotative Wing Aircraft (July 13, 1937).
Irrotational rotors (June 6, 1944).
Helicopters (February 6, 1945)
Rotary Wing Aircraft (February 6, 1945).
Helicopters (November 6, 1945).
Helicopters (June 11, 1946).
Repository Details
Part of the University of Kansas. Kenneth Spencer Research Library Repository