Method for controlling the deformation of a surface of a sail of a sailing boat during a direction change manoeuvre

Abstract

There is described a method for controlling the deformation of a surface of a sail ( 1 ) of a sailing boat ( 100 ) during a direction change manoeuvre, said method comprising the step of arranging at least one inflatable batten ( 10 ) into a respective seat ( 3 ) formed on a side surface ( 2 a ) of the sail ( 1 ), said at least one batten ( 10 ) being inflated at a predetermined working pressure, said working pressure being such as to impart to said at least one batten ( 10 ) a bending stiffness having, with no bending load, a predetermined value and the step of carrying out a manoeuvre for changing the direction of the sailing boat ( 100 ), wherein in a first part of said manoeuvre said at least one batten ( 10 ) is subjected to the action of an increasing bending load and in a second part of said manoeuvre, said bending load ends its action on said at least one batten ( 10 ), during said manoeuvre the mechanical properties of said at least one batten ( 10 ) being changed so that as said bending load increases in said first part of the manoeuvre, the value of the bending stiffness of said at least one batten ( 10 ) decreases considerably, and as the action of said bending load ends in said second part of the manoeuvre, the bending stiffness of said at least one batten ( 10 ) returns to said predetermined value. Such method is carried out by using a sail ( 1 ) provided with at least one batten ( 10 ) comprising a fluid impervious wrapping ( 31 ) adapted to be inflated by a fluid under pressure and a reinforcing structure ( 33 ) associated externally with said wrapping ( 31 ) and comprising a plurality of reinforcing thread-like elements ( 34 a, 34 b ) arranged crossed with an angle comprised between about 65° and about 115°.

1 . A method for controlling the deformation of a surface of a sail ( 1 ) of a sailing boat ( 100 ) during a direction change manoeuvre, said method comprising the steps of:
 arranging at least one inflatable batten ( 10 ) into a respective seat ( 3 ) obtained on a side surface ( 2   a ) of a sail ( 1 ) of a sailing boat ( 100 ), said at least one inflatable batten ( 10 ) being inflated at such a pressure as to impart to said at least one inflatable batten ( 10 ) a bending stiffness having, with no bending load, a predetermined value;   carrying out a direction change manoeuvre of the sailing boat ( 100 ), wherein in a first part of said manoeuvre said at least one batten ( 10 ) is subjected to the action of an increasing bending load and in a second part of said manoeuvre said bending load ends its action on said at least one batten ( 10 ), during said manoeuvre the mechanical properties of said at least one batten being modified so that as said bending load increases in said first part of the manoeuvre, the value of the bending stiffness of said at least one batten ( 10 ) decreases considerably and as said bending load ends its action in said second part of the manoeuvre, the bending stiffness of said at least one batten ( 10 ) returns to said predetermined value.   
     
     
         2 . A method according to  claim 1 , wherein the value of said bending stiffness decreases to be comprised between about 0.01% and about 50% of said predetermined value. 
     
     
         3 . A method according to  claim 1 , wherein the value of said bending stiffness decreases to be comprised between about 0.01% and about 30% of said predetermined value. 
     
     
         4 . A method according to  claim 1 , wherein the value of said bending stiffness decreases to be comprised between about 0.01% and about 10% of said predetermined value. 
     
     
         5 . A method according to  claim 1 , wherein the value of said bending stiffness decreases to be comprised between about 0.01% and about 5% of said predetermined value. 
     
     
         6 . A method according to  claim 1 , wherein for a bending load higher than a predetermined threshold value, the bending stiffness of said at least one batten ( 10 ) is substantially null. 
     
     
         7 . A method according to any one of the previous claims, wherein said predetermined value of bending stiffness with no bending load is comprised between about 10 Nm 2  and about 100 Nm 2 . 
     
     
         8 . A method according to any one of the previous claims, wherein said batten ( 10 ) is inflated at an operating pressure comprised between about 5 bar and about 50 bar. 
     
     
         9 . A method according to  claim 8 , wherein said working pressure is comprised between about 15 bar and about 50 bar for battens with an inner diameter comprised between about 20 mm and about 35 mm. 
     
     
         10 . A method according to  claim 8 , wherein said working pressure is comprised between about 5 bar and about 30 bar for battens with a diameter comprised between about 35 mm and about 70 mm. 
     
     
         11 . A method according to any one of the previous claims, wherein said at least one batten ( 10 ) comprises a reinforcing structure ( 33 ) comprising a plurality of reinforcing thread-like elements ( 34   a ,  34   b ) arranged crossed to one another. 
     
     
         12 . A method according to  claim 11 , wherein the above reinforcing thread-like elements ( 34   a ,  34   b ) are arranged crossed at a predetermined angle comprised between about 65° and about 115°. 
     
     
         13 . A method according to  claim 11 , wherein the above reinforcing thread-like elements ( 34   a ,  34   b ) are arranged crossed at a predetermined angle comprised between about 70° and about 110°. 
     
     
         14 . A method according to  claim 11 , wherein the above reinforcing thread-like elements ( 34   a ,  34   b ) are arranged crossed at a predetermined angle comprised between about 80° and about 100°. 
     
     
         15 . A method according to  claim 11 , wherein the above reinforcing thread-like elements ( 34   a ,  34   b ) are arranged crossed at a predetermined substantially right angle. 
     
     
         16 . A method according to any one of the previous claims, wherein said at least one batten ( 10 ) comprises a fluid impervious wrapping ( 31 ) containing a fluid at a working pressure. 
     
     
         17 . A method according to  claim 16 , wherein a reinforcing structure ( 33 ) is associated with said fluid impervious wrapping ( 31 ). 
     
     
         18 . A method according to  claim 17 , wherein said reinforcing structure ( 33 ) is external to said fluid impervious wrapping ( 31 ). 
     
     
         19 . A method according to any one of claims from  11  to  18 , wherein said reinforcing structure ( 33 ) is closed at the ends of said batten ( 10 ). 
     
     
         20 . A sail ( 1 ) for sailing boats ( 100 ), comprising:
 at least one seat ( 3 ) for a respective batten ( 10 );   at least one inflatable batten ( 10 ) housed into said at least one seat ( 3 ), said at least one inflatable batten ( 10 ) comprising:
 a fluid impervious wrapping ( 31 ) containing a fluid under pressure, said fluid being at such pressure as to impart a bending stiffness to said at least one batten ( 10 ) having, with no bending load, a predetermined value; 
 a reinforcing structure ( 33 ) associated with said wrapping ( 31 ) and comprising a plurality of reinforcing thread-like elements ( 34   a ,  34   b ) arranged crossed to each other; 
   
       said at least one batten ( 10 ) being such that, when subjected to an increasing bending load, the bending stiffness thereof decreases considerably and when said bending load ends its action, the bending stiffness thereof returns to said predetermined value. 
     
     
         21 . A sail ( 1 ) according to  claim 20 , wherein the above reinforcing thread-like elements ( 34   a ,  34   b ) are arranged crossed at a predetermined angle comprised between about 65° and about 115°. 
     
     
         22 . A sail ( 1 ) according to  claim 20 , wherein the above reinforcing thread-like elements ( 34   a ,  34   b ) are arranged crossed at a predetermined angle comprised between about 70° and about 110°. 
     
     
         23 . A sail ( 1 ) according to  claim 20 , wherein the above reinforcing thread-like elements ( 34   a ,  34   b ) are arranged crossed at a predetermined angle comprised between about 80° and about 100°. 
     
     
         24 . A sail ( 1 ) according to  claim 20 , wherein the above reinforcing thread-like elements ( 34   a ,  34   b ) are arranged crossed at a predetermined substantially right angle. 
     
     
         25 . A sail ( 1 ) according to any one of claims from  20  to  24 , wherein said reinforcing structure ( 33 ) comprises a layer comprising first reinforcing thread-like elements ( 34   a ) arranged along a first direction and second reinforcing thread-like elements ( 34   b ) arranged along a second direction inclined, relative to said first direction, by said predetermined angle. 
     
     
         26 . A sail ( 1 ) according to any one of claims from  20  to  24 , wherein said reinforcing structure ( 33 ) comprises two overlapped layers ( 33   a ,  33   b ) of reinforcing thread-like elements, a first layer ( 33   a ) comprising first reinforcing thread-like elements ( 34   a ) arranged along a first direction and a second layer ( 33   b ) comprising second reinforcing thread-like elements ( 34   b ) arranged along a second direction inclined, relative to said first direction, by said predetermined angle. 
     
     
         27 . A sail ( 1 ) according to  claim 25  or  26 , wherein said second reinforcing thread-like elements ( 34   b ) are arranged parallel to one another along a substantially longitudinal direction of said batten ( 10 ). 
     
     
         28 . A sail ( 1 ) according to  claim 25  or  26 , wherein said second reinforcing thread-like elements ( 34   b ) extend along respective paths having an angle of inclination comprised between about +20° and about −20° relative to a longitudinal direction of said batten ( 10 ). 
     
     
         29 . A sail ( 1 ) according to  claim 25  or  26 , wherein said first reinforcing elements ( 34   a ) are arranged parallel to one another along a substantially circumferential direction of said batten ( 10 ). 
     
     
         30 . A sail ( 1 ) according to  claim 25  or  26 , wherein said first reinforcing thread-like elements ( 34   a ) extend along respective paths having an angle of inclination comprised between about +5° and about −5° relative to a circumferential direction of said batten ( 10 ). 
     
     
         31 . A sail ( 1 ) according to any one of claims from  26  to  30 , wherein said second layer ( 33   b ) is arranged outside said first layer ( 33   a ). 
     
     
         32 . A sail ( 1 ) according to any one of claims from  20  to  31 , wherein said reinforcing thread-like elements ( 34   a ,  34   b ) comprise cords made of kevlar. 
     
     
         33 . A sail ( 1 ) according to any one of claims from  20  to  32 , wherein said reinforcing thread-like elements ( 34   a ,  34   b ) are incorporated in a vulcanised elastomeric material. 
     
     
         34 . A sail ( 1 ) according to any one of claims from  20  to  33 , wherein said at least one batten ( 10 ) further comprises, at a first end ( 10   a ) thereof, a first closing cap ( 40   a ). 
     
     
         35 . A sail ( 1 ) according to any one of claims from  20  to  34 , wherein said at least one batten ( 10 ) comprises, at a second end ( 10   b ) thereof, a second closing cap ( 40   b ) comprising an inflating/deflating valve ( 47 ). 
     
     
         36 . A sail ( 1 ) according to  claims 34  and  35 , wherein said first and second closing caps ( 40   a ,  40   b ) comprise a tubular sleeve ( 41   a ,  41   b ) sealingly coupled to an inner surface of said fluid impervious wrapping ( 31 ). 
     
     
         37 . A sail ( 1 ) according to  claim 36 , wherein said tubular sleeve ( 41   a ,  41   b ) comprises a first sealing lip ( 43   a ,  43   b ) in abutment against a front end surface of said fluid impervious wrapping ( 31 ) and a tubular collar ( 42   a ,  42   b ) sealingly coupled to an outer surface of said reinforcing structure ( 33 ) and to said sleeve ( 41   a ,  41   b ). 
     
     
         38 . A sail ( 1 ) according to  claim 36 , wherein said inflating/deflating valve ( 47 ) is associated with a front surface ( 44   b ) of said sleeve ( 41   b ), said sleeve ( 41   b ) further comprising a protection lip ( 49 ) for said inflating/deflating valve ( 47 ). 
     
     
         39 . A sail ( 1 ) according to  claim 38 , wherein said protection lip ( 49 ) comprises a tapered side surface ( 490 ). 
     
     
         40 . A sail ( 1 ) according to any one of claims from  20  to  39 , wherein said at least one batten ( 10 ) has a substantially tubular shape with a circular section substantially constant along the entire longitudinal extension thereof. 
     
     
         41 . A sail ( 1 ) according to any one of claims from  20  to  39 , wherein said at least one batten ( 10 ) has a substantially cylindrical shape with at least one cone tapered end. 
     
     
         42 . A sail ( 1 ) according to  claims 34  and  35 , wherein the reinforcing thread-like elements ( 34   a ,  34   b ) are connected to the above first ( 40   a ) and second ( 40   b ) closing caps. 
     
     
         43 . A sail ( 1 ) according to  claims 34  and  35 , wherein the second reinforcing thread-like elements ( 34   b ) are connected to the above first ( 40   a ) and second ( 40   b ) closing caps. 
     
     
         44 . A sail ( 1 ) according to any one of claims from  20  to  43 , wherein said predetermined value of bending stiffness with no bending load is comprised between about 10 Nm 2  and about 100 Nm 2 . 
     
     
         45 . A sail ( 1 ) according to any one of claims from  20  to  44 , wherein said batten ( 10 ) is inflated at an operating pressure comprised between about 5 bar and about 50 bar. 
     
     
         46 . A sail ( 1 ) according to any one of claims from  20  to  45 , wherein said reinforcing structure ( 33 ) is external to said fluid impervious wrapping ( 31 ). 
     
     
         47 . A sail ( 1 ) according to any one of claims from  20  to  46 , wherein said sail is a genoa or a mainsail. 
     
     
         48 . A batten ( 10 ) for sails ( 1 ) of a sailing boat ( 100 ), comprising:
 a fluid impervious wrapping ( 31 ) adapted to be inflated by a fluid under pressure, wherein such fluid under pressure imparts a bending stiffness to said batten ( 10 ), said bending stiffness having, with no bending load, a predetermined value;   a reinforcing structure ( 33 ) associated with said wrapping ( 31 ) and comprising a plurality of reinforcing thread-like elements ( 34   a ,  34   b ) arranged crossed at a predetermined angle comprised between about 65° and about 115°;   
       wherein, when said wrapping ( 31 ) is inflated at said working pressure and said batten ( 10 ) is subjected to an increasing bending load, the bending stiffness thereof decreases considerably and when said bending load ends its action, the bending stiffness thereof returns to said predetermined value. 
     
     
         49 . A batten ( 10 ) according to  claim 48 , wherein said predetermined angle is comprised between about 70° and about 110°. 
     
     
         50 . A batten ( 10 ) according to  claim 48 , wherein said predetermined angle is comprised between about 80° and about 100°. 
     
     
         51 . A batten ( 10 ) according to  claim 48 , wherein said predetermined angle is substantially a right angle. 
     
     
         52 . A batten ( 10 ) according to any one of claims from  48  to  51 , wherein said reinforcing structure ( 33 ) comprises a layer comprising first reinforcing thread-like elements ( 34   a ) arranged along a first direction and second reinforcing thread-like elements ( 34   b ) arranged along a second direction inclined, relative to said first direction, by said predetermined angle. 
     
     
         53 . A batten ( 10 ) according to any one of claims from  48  to  51 , wherein said reinforcing structure ( 33 ) comprises two overlapped layers ( 33   a ,  33   b ) of reinforcing thread-like elements ( 34   a ,  34   b ), a first layer ( 33   a ) comprising first reinforcing thread-like elements ( 34   a ) arranged along a first direction and a second layer ( 33   b ) comprising second reinforcing thread-like elements ( 34   b ) arranged along a second direction inclined, relative to said first direction, by said predetermined angle. 
     
     
         54 . A batten ( 10 ) according to  claim 52  or  53 , wherein said second reinforcing thread-like elements ( 34   b ) are arranged parallel to one another along a substantially longitudinal direction of said batten ( 10 ). 
     
     
         55 . A batten ( 10 ) according to  claim 52  or  53 , wherein said second reinforcing thread-like elements ( 34   b ) extend along respective paths having an angle of inclination comprised between about +20° and about −20° relative to a longitudinal direction of said batten ( 10 ). 
     
     
         56 . A batten ( 10 ) according to  claim 52  or  53 , wherein said first reinforcing thread-like elements ( 34   a ) are arranged parallel to one another along a substantially circumferential direction of said batten ( 10 ). 
     
     
         57 . A batten ( 10 ) according to  claim 52  or  53 , wherein said first reinforcing thread-like elements ( 34   a ) extend along a direction having an angle of inclination comprised between about +5° and about −5° relative to a circumferential direction of said batten ( 10 ). 
     
     
         58 . A batten ( 10 ) according to any one of claims from  53  to  57 , wherein said second layer ( 33   b ) is arranged outside said first layer ( 33   a ). 
     
     
         59 . A batten ( 10 ) according to any one of claims from  48  to  58 , wherein said reinforcing thread-like elements ( 34   a ,  34   b ) comprise cords made of kevlar. 
     
     
         60 . A batten ( 10 ) according to any one of claims from  48  to  59 , wherein said reinforcing thread-like elements ( 34   a ,  34   b ) are incorporated in a vulcanised elastomeric material. 
     
     
         61 . A batten ( 10 ) according to any one of claims from  48  to  60 , further comprising a first closing cap ( 40   a ) at a first end ( 10   a ) thereof. 
     
     
         62 . A batten ( 1 ) according to any one of claims from  48  to  61 , further comprising a second closing cap ( 40   b ) at a second end ( 10   b ) thereof, comprising an inflating/deflating valve ( 47 ). 
     
     
         63 . A batten ( 10 ) according to  claims 61  and  62 , wherein said first and second closing caps ( 40   a ,  40   b ) comprise a tubular sleeve ( 41   a ,  41   b ) sealingly coupled to an inner surface of said fluid impervious wrapping ( 31 ). 
     
     
         64 . A batten ( 10 ) according to  claim 63 , wherein said tubular sleeve ( 41   a ,  41   b ) comprises a first sealing lip ( 43   a ,  43   b ) in abutment against a front end surface of said fluid impervious wrapping ( 31 ) and a tubular collar ( 42   a ,  42   b ) sealingly coupled to an outer surface of said reinforcing structure ( 33 ) and to said sleeve ( 41   a ,  41   b ). 
     
     
         65 . A batten ( 10 ) according to  claim 63 , wherein said inflating/deflating valve ( 47 ) is associated with a front surface ( 44   b ) of said sleeve ( 41   b ), said sleeve ( 41   b ) further comprising a protection lip ( 49 ) for said inflating/deflating valve ( 47 ). 
     
     
         66 . A batten ( 10 ) according to  claim 65 , wherein said protection lip ( 49 ) comprises a tapered side surface ( 490 ). 
     
     
         67 . A batten ( 10 ) according to any one of claims from  48  to  66 , wherein said batten ( 10 ) has a substantially tubular shape with a circular section substantially constant along the entire longitudinal extension thereof. 
     
     
         68 . A batten ( 10 ) according to any one of claims from  48  to  66 , wherein said batten ( 10 ) has a substantially cylindrical shape with at least one cone tapered end. 
     
     
         69 . A batten ( 10 ) according to  claims 61  and  62 , wherein the reinforcing thread-like elements ( 34   a ,  34   b ) are connected to the above first ( 40   a ) and second ( 40   b ) closing caps. 
     
     
         70 . A batten ( 10 ) according to  claims 61  and  62 , wherein the second reinforcing thread-like elements ( 34   b ) are connected to the above first ( 40   a ) and second ( 40   b ) closing caps. 
     
     
         71 . A batten ( 10 ) according to any one of claims from  48  to  70 , wherein said predetermined value of bending stiffness with no bending load is comprised between about 10 Nm 2  and about 100 Nm 2 . 
     
     
         72 . A batten ( 10 ) according to any one of claims from  48  to  71 , wherein said batten ( 10 ) is inflated at an operating pressure comprised between about 5 bar and about 50 bar. 
     
     
         73 . A batten ( 10 ) according to any one of claims from  48  to  72 , wherein said reinforcing structure ( 33 ) is external to said fluid impervious wrapping ( 31 ).