Patent ID: 6863008

Claim:
A flexible wing-sail for wind-propelled vehicles, comprising: a mast to be rotatably mounted in a vertical position on the vehicle enabling the flexible wing-sail to freely rotate and assume parallel direction to the apparent wind; a plurality of flexible sail panels carried by said mast and including first, second and third sail panels defining the opposite sides and the trailing edge of the flexible wing-sail, and a third sail panel defining the leading edge of the flexible wing-sail; a spreader assembly securing said sail panels to the mast and imparting to the sail panels an airfoil shape having a leading edge fore of the mast, and a trailing edge aft of the mast; a boom pivotally coupled above deck to the bottom of said mast and including a slidable coupling to the trailing edge of each of said first and second sail panels; and a brake for selectively locking the mast against rotation with respect to the vehicle, such that pivoting the boom while the mast is locked against rotation, changes the curvature of the airfoil shape defined by the first and second sail panels according to the apparent wind direction and velocity.