Aerofoil sail
OwnerBarry Wainwrightinventor
Life of this patent
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Abstract
An aerofoil sail has a rigid main panel (10) pivotally mounted to a hull (17) about a vertical axis (15) with trailing a flap (12A) hinged (14) to one side of the main panel. The trailing flap comprises a series of separate flaps (12A' ,12A" ,12A'") individually settable so that the angle of incidence can differ (.alpha.,.beta.) at different levels on the sail. Alternatively, a single trailing flap can be torsionally flexible so that the angle of incidence can differ along its length. In a preferred form flaps (12A,12B) are provided at opposite edges of main panel (10) and can be alternatively folded in to give a reversible aerofoil section.
Claims3
An aerofoil sail comprising a rigid main panel and an essentially rigid flap hinged to one side thereof, the trailing flap having a degree of torsional flexibility whereby it can twist to provide different angles of incidence at opposite ends thereof, a plurality of stop means being along the edge of the flap provided to limit the hinging of the flap in an extended condition, the stop means at the lower end of the sail being initially engageable when the flap moves into extended condition, the remaining stop means being engageable as a result of further pressure on the flap causing the flap to twist, so that the angle of incidence to the air flow can be lower at the top of the sail than at the bottom of the sail.
Dependencies are inferred from the claim text.