Flexible wing rib sail

Claim 1

A sail assembly attached to a cylindrical mast, the assembly comprising: (a) a sail having a sock enclosing the mast and a main section with a trailing edge, the main section joining the sock at a sock seam, the sail further comprising: (i) a plurality of batten pockets on the main section and extending freely within the sock to points proximate to the mast; (ii) a plurality of rib pocket pairs on the sock interrupting the seam opposite corresponding batten pockets, the rib pocket pairs extending parallel to the batten pockets on each side of the main section; (b) a leading edge member within the sock for defining an aerodynamic shape opposite the sock seam; (c) a plurality of anchors fixedly fastened to the leading edge member for pivotably locating the leading edge member to the mast, the anchors being aligned with and fastened to the corresponding batten pockets; (d) a plurality of battens in the corresponding batten pockets, the battens guided into fixed engagement with the anchors by the batten pockets, the battens extending proximately to the trailing edge of the sail; and (e) a plurality of flexible rib pairs fastened tangent to the leading edge member on opposite sides of the mast and extending into the corresponding rib pocket pairs, the rib pairs being slidably clamped by the rib pocket pairs substantially tangent to opposite sides of the corresponding battens, the assembly being adapted to automatically position the leading edge member into relative wind and to define a smooth aerodynamic shape of the sock blending with both sides of the main section as the sail is variously trimmed.