Hartzell Propeller Inc.

Richard L Edinger

Mark W Spoltman

Richard D Bowerman

A generally flat core of foam material extends outwardly from a wedge-shaped metal base plug, and the core is covered with overlapping plies of resin-bonded plastics materials having unidirectional fibers. The plies are covered by outer layers or skins of resin-bonded woven fabric plastics materials. The fibers of the inner plies are orientated at positive and negative acute angles relative to the longitudinal axis of the blade to provide the blade with predetermined torsional stiffness, and the fibers of the outer plies extend generally parallel to the axis and wrap around the base plug in an interleaving manner to provide high stiffness and strength to bending forces. Some of the plies extending around the base plug receive metal shell elements, and the shell elements engage propeller hub lip portions which cooperate to define an under-cut recess and clamp the plies to the base plug.

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Piqua, OH, United States of America

Richard L Edinger