Construction of airfoils having elastically-bent afterbodies

Claim 1

AN AIRFOIL OF THE TYPE HAVING UPPER AND LOWER AFT SKINS UNSUPPORTED BETWEEN A SPAR AND A TRAILING EDGE JUNCTURE OF SAID SKINS, COMPRISING A SPAR HAVING CONVEX AIRFOIL-CONTOUR-CONFORMING FACES RECESSED WITHIN THE OUTER CONTOUR OF THE AIRFOIL ADJACENT AND EXTENDING TO THE SPAR EDGE AND TERMINATING IN SPREADER ENDS, TOGETHER WITH UPPER AND LOWER AFT SKINS HAVING FORWARD MARGINS ADHERED TO SAID RECESSED FACES AND, BY SUCH ADHERENCE, CONSTRAINED ELASTICALLY STRESSED FROM FLAT TO CONTOUR-CONFORMING ALIGNMENT WITH SAID FACES, WHEREBY CONVEXITY OF CURVATURE IS IMPOSED ON THE FORWARD SKINS MARGINS, SAID AFT SKINS HAVING ADHERED-TOGETHER REAR MARGINS DEMARKED FORWARDLY BY A PERMANENTLY-SET ANGULAR BEND AND DEMARKED REARWARDLY BY THE TRAILING EDGE LINE, SAID ANGULAR BEND BEING AT SUCH ANGLE AS TO SO SPACE THE FORWARD MARGINS THAT THE SPREADER ENDS IMPOSE UPON THEM OUTWARD THRUST, WHEREBY SUCH CONVEXITY OF CURVATURE IS REDUCED PROGRESSIVELY AFT, WHEREBY A CUSP-LIKE TRAILING EDGE JUNCTURE IS FORMED ACROSS WHICH ELASTIC STRESSES IN EACH OF THE UPPER AND LOWER SKINS ARE TRANSMITTED TO THE OTHER OF SAID SKINS AND RESISTED BY IT, THE MARGIN CONSTRAINTS THUS IMPOSED ON SAID UPPER AND LOWER SKINS HOLDING THEM ELASTICALLY IN THE CONFORMATION OF AN AIRFOIL AFTERBODY CHARACTERIZED BY CONVEXITY OF CURVATURE DECREASING FROM THE SPAR TO THE TRAILING EDGE JUNCTURE.