Patent ID: 6431100
Filing Date: 2002-08-13
Classification: B63H

Abstract:
A semi rigid airfoil assembly, functioning automatically with respect to an airflow, as a draft adjusting wing sail or as a spinnaker sail, for use with a freestanding mast having a halyard on a wind powered craft, the improvement wherein, said semi rigid airfoil is a stowable rigid wing, and has a plurality of higher lift to drag ratio characteristics, of the type comprising:(a) a port and a starboard semi rigid sail which are vertically disposed consisting of a plurality of rigid foam core panels that are sandwiched horizontally with an adhesive between an inboard and an outboard flexible sailcloth material, thereby having a separating space between each rigid panel, whereby the separating spaces are a flexible sailcloth material lamination and are a means wherein the rigid panels bend in an alternating accordion form of a plurality of inward and outward folds, thereby folding the semi rigid sails downward and over an outside of and connected to a â€œwing chord section shapedâ€  boom that is in a parallel disposition to the rigid panels and separating spaces; (b) the port and starboard sails to each have a plurality of midchord spanwise and leading edge airflow slots for higher lift, and the slots airflow to exit between a trailing spanwise port and starboard sails edges, along with the trailing edges to also each have a plurality of concave depressions for low stall, the high lift slots altogether combined with the low stall concavities for a decreased vertical drag vortice abaft the wing sail; (c) means provided for mounting the airfoil assembly from a head of the sail to a foot of the sail so as to partially or entirely surround the mast; (d) means provided for a shape control of the sails to be a wing chord section profile; (e) means provided for a plurality of downhauls with a reefing operation of the sail panels; (f) a â€œfull draft wing chord section profileâ€  flexible boom slidably attached to the mast by means of a telescoping foreboom pivotably connected to the mast, and for a port and a starboard draft control arm to adjustably pivot a full draft of the flexible boom inboard to a â€œminimum draft wing chord section profileâ€ , the leading edge of the boom to be a pivotable connection of a port and a starboard side of the boom, the booms' pivotable connection being attached to a forward end of the telescoping foreboom, thereby an alternate movement of a port and starboard sides of the boom away from the mast; (g) means provided for a plurality of spare folded sail panels to be stowed.