Patent ID: 8348618

Claim:
A blade construction for a wind turbine comprising an assembly of an airfoil profile and an unsymmetrical I beam, said airfoil profile elongated in a first direction and having; a single interior surface having features congruent to said unsymmetrical I beam in at least three locations of contact for receiving and aligning said unsymmetrical I beam along the length of said airfoil profile, and an exterior surface corresponding to a uniform aerodynamic shape along the length of said airfoil profile with a leading edge and a trailing edge, said leading edge and said trailing edge connected by a chord line, with said airfoil profile divided by said chord line into a convex upper side and an opposing lower side, said interior surface being roughly congruent to said exterior surface except at said at least three locations of contact, said unsymmetrical I beam elongated in said first direction and having perpendicular to said first direction; a web section of constant width and thickness with a roughly flat medial plane and a longitudinal central axis, said web section integral with two flanges; a first flange near said leading edge and a second flange near said trailing edge, with both said flanges aligned roughly perpendicular to said medial plane and each having flange tips, said flange tips positioned asymmetrically about said central axis, said first flange and said second flange having constant widths along said first direction and having variable widths, relative to one another, with both said flanges directly bonded to said single interior surface at said flange tips along roughly parallel lines extending from said at least three locations of contact in said completed blade construction along the length of said airfoil profile, said medial plane forming a designed angle with said chord line perpendicular to said first direction and said blade construction defining a surface of rotation during operation of said wind turbine, with said web section, said lower side between said two flanges and said two flanges comprising a roughly triangular structural member running the length of said blade construction, and said web section, said upper side between said two flanges and said two flanges comprising a shallow box beam structural member running the length of said blade construction said web section comprising a principal attachment surface to said wind turbine near at least one end of said blade construction with said wind turbine additionally including; at least one mating hub that overlaps said attachment surface and conventional fasteners that secure said attachment surface to said at least one mating hub, whereby: said triangular structural member and said box beam structural member form a tiered structural assembly running along the length of said blade construction and said tiered assembly resists deformation by aerodynamic and rotational forces incurred during operation of said wind turbine.