Light weight contoured load carrying structure

Claim 1

A lightweight foil structure for mounting in a cantalever arrangement comprising: a plurality of elongated load carrying filament wound fiberglass tubular members disposed in side by side relationship and varying in cross section from one to the other to have the opposite lateral sides thereof cooperate in defining the contour of the foil cross section that progressively increases in thickness from the leading edge of said foil cross section to form an intermediate portion defining a maximum thickness and to then progressively decrease in thickness to terminate in a relatively thin trailing edge; fiberglass retaining means secured over said tubular members and cooperating therewith to form longitudinal cavities, said retaining means defining the external cross-section of said foil structure; and lightweight filler means filling said cavities to closely fit the peripheries of said tubular members and having sufficient resistance to compression under normal operating conditions to provide for transfer of loads from said retaining means to said tubular means to cause said tubular means to cooperate with said retaining means in supporting said tubular members against buckling whereby lifting loads applied to the tip end of said structure as mounted cantaleverly which result in longitudinal bending moments will be resisted by said filament wound tubular members and buckling of said members will be resisted by said filler means in cooperation with said retaining means.