Structural Support Scheme for the Replacement of Trailing Portions of Sails

Abstract

A sail for a wind-powered craft includes a web which forms a flying shape upon engagement with the wind, flying shape extending from leading to trailing edges. The web includes a combination of wind-impermeable and wind-permeable portions disposed between the leading and trailing edges, with a permeability ratio of wind-permeable area to wind-impermeable area within a range of about 5 to 80 percent.

Having thus described the invention, what is claimed is: 
     
         1 . A sail for providing wind-powered motive force for a craft, the sail comprising:
 a web configured for forming a flying shape upon engagement with the wind, the flying shape extending from a leading edge to a trailing edge;   said web including a combination of one or more substantially wind-impermeable portions, and one or more substantially wind-permeable portions, said wind-permeable portions being disposed between the leading and trailing edges; and   the web having a permeability ratio of wind-permeable area to wind-impermeable area within a range of about 5 to 80 percent.   
     
     
         2 . The sail of  claim 1 , wherein the permeability is fixed. 
     
     
         3 . The sail of  claim 1 , wherein the wind-permeable portions are configured to support the flying shape of the wind impermeable portion. 
     
     
         4 . The sail of  claim 1 , wherein the permeability ratio is within a range of about 10 to 40 percent. 
     
     
         5 . The sail of  claim 1 , wherein the flying shape is disposed in the form of at least one of an upwind mainsail, a headsail, a reaching sail, a downwind sail, spinnaker, a code zero, and a jib. 
     
     
         6 . The sail of  claim 1 , wherein the flying shape is disposed in the form of a downwind sail. 
     
     
         7 . The sail of  claim 1 , wherein the flying shape is asymmetrical. 
     
     
         8 . The sail of  claim 1 , wherein the flying shape is symmetrical. 
     
     
         9 . The sail of  claim 8 , comprising a clew portion and a tack portion, the clew portion and tack portions being interchangeable with one another depending on the orientation of the craft. 
     
     
         10 . The sail of  claim 8 , wherein said wind-permeable portions are disposed symmetrically on opposite sides of the sail. 
     
     
         11 . The sail of  claim 1 , wherein the wind-permeable portion comprises a plurality of spaced lines. 
     
     
         12 . The sail of  claim 11 , wherein the sail comprises a leading portion and a trailing portion, the wind-permeable portion being disposed within the trailing portion. 
     
     
         13 . The sail of  claim 12 , wherein the wind-permeable portion extends within a clew portion of the sail. 
     
     
         14 . The sail of  claim 11 , wherein the plurality of spaced lines are selected from the group consisting of strings, ropes, ribbons, meshes, and combinations thereof. 
     
     
         15 . The sail of  claim 11 , fabricated from materials selected from the group consisting of natural fabrics, synthetic fabrics, plastics, composite materials, synthetic materials, polyamide, polyethylene terephthalate, aramid, carbon fiber; HMPE (high molecular weight polyethylene), thermoset liquid crystalline polyoxazole, and mixtures and laminates thereof. 
     
     
         16 . The sail of  claim 1 , having a foot extending along one edge of the sail, and a leech extending along another edge of the sail, the foot and leech each terminating at a clew, wherein the wind-permeable portion extends in a direction substantially parallel to the foot, for a distance between about 2 to 50 percent of the length of the foot. 
     
     
         17 . The sail of  claim 16 , wherein the wind-permeable portion extends in a direction substantially parallel to the foot, for a distance between about 5 to 20 percent of the length of the foot. 
     
     
         18 . The sail of  claim 16 , wherein the wind-permeable portion extends in a direction substantially parallel to the leech, for a distance between about 2 to 95 percent of the length of the leech. 
     
     
         19 . The sail of  claim 18 , wherein the wind-permeable portion extends in a direction substantially parallel to the leech, for a distance between about 5 to 60 percent of the length of the leech. 
     
     
         20 . The sail of  claim 1 , further comprising:
 a head portion configured for being coupled to an upper end of a mast disposed on the craft;   a tack portion configured for being coupled near a deck, bowsprit, or spinnaker pole of the craft; and   a clew portion configured for being coupled to one or more control lines for trimming the a web supported between said head portion, said tack portion, and said clew portion.   
     
     
         21 . A sail for providing wind-powered motive force for a craft, the sail comprising:
 a head portion configured for being coupled to an upper end of a mast disposed on the craft;   a tack portion configured for being coupled to a deck, bowsprit, or spinnaker pole of the craft;   a clew portion configured for being coupled to one or more control lines for trimming the sail;   a web supported between said head portion, said tack portion, and said clew portion;   said web including a combination of one or more substantially wind-impermeable portions in the form of fabric or similar material, and one or more substantially wind-permeable portions in the form of widely spaced strings or lines, the wind-permeable portions extending from the clew portion on a trailing portion of the sail;   a ratio of the wind-permeable portions to wind-impermeable portions within a range of about 10-40 percent; and   the sail being asymmetrical, or symmetrical wherein wind-permeable portions are disposed symmetrically on opposite sides of the sail with the clew and tack portions being interchangeable depending on the orientation of the craft.   
     
     
         22 . A method for configuring a sail for providing wind-powered motive force to a craft, the method comprising:
 configuring a web for forming a flying shape upon engagement with the wind, the flying shape extending from a leading edge to a trailing edge;   providing the web with a combination of one or more substantially wind-impermeable portions and one or more substantially wind-permeable portions disposed between the leading and trailing edges; and   providing the web with a permeability ratio of wind-permeable area to wind-impermeable area within a range of about 5 to 80 percent.