Patent Publication Number: US-11643179-B2

Title: Sail

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of and claims the right of priority from International Application PCT/IB2019/050765 having a filing date of Jan. 31, 2019, which claims the right of priority to New Zealand Patent Application NZ 739652 having a filing date of Feb. 2, 2018. The entirety of the contents of these respective applications are hereby incorporated by reference. 
    
    
     FIELD OF INVENTION 
     The present invention relates to a sail. More particularly but not exclusively it relates to a nestable wing sail that can change its surface area by partial extension and retraction in a fore aft direction. 
     BACKGROUND 
     Yachts may be desired to be sailed in a variety of wind conditions. A yacht is preferably able to be optimised for different conditions, in particular the sail area may need to be adjusted. Sails are generally of two basic constructions soft, fabric-shaped sails that are shell like, and wing sails which form a 3D cross section wing shape. Typically, a mainsail is reefed to decrease its sail area. A reef reduces the area of a sail, usually by folding or furling one edge of the sail in on itself. This may be achieved by retracting the mainsail downwards towards the boom, or forward towards the mast. Where the main sail is a wing sail, which is a solid sail that is not able to be reefed, it may be difficult to decrease the area of the sail. One way of achieving a different sail area is by changing the wing sail for a wing sail of a different area, this requires stepping and un-stepping wing sails. 
     It is an object of the present invention to provide a nestable wing sail that overcomes or at least partially ameliorates some of the abovementioned disadvantages or which at least provides the public with a useful choice. 
     STATEMENTS OF INVENTION 
     In a first aspect the present invention relates to a wing sail for a yacht, the wing sail comprising at least two sail sections, 
     a primary section attached, integral with, or comprising a mast, and two skins forming an aerofoil surface forming the primary section, the primary section further comprising a leech at aft edges where the two skins converge, and 
     a movable section configured to move between a first condition where the movable section is nested or partially nested within or at the leech of the primary section, and a second condition where the movable section extends from at least part of the leech intermediate the two skins. 
     In one embodiment, the primary section comprises a cavity defined by the sides, that can receive the movable section. 
     In one embodiment, the primary section and movable section comprise sail area that make up the sail area of the wing sail. 
     In a further aspect the present invention relates to a sail for a yacht, the sail comprising at least two sail sections, a primary section forming an aerofoil wing shape having a cavity intermediate port and starboard face sides which converge to form at the primary section a leech, and at least one movable section moveable between a first condition where the movable section is enveloped or partially enveloped in the cavity or otherwise stored at the leech, and a second condition where at least a portion of the movable section extends from the leech out of the cavity intermediate the primary section leech, 
     where in the second condition the movable section adds to the sail area of the sail. 
     In one embodiment, the sides comprise aerofoil surfaces. 
     In one embodiment, the movable section is nested or partially nested within the primary section. 
     The below embodiments may relate to any of the above statements of invention. 
     In one embodiment, in the first condition the movable section is fully nested within the primary section so that the leech of the primary section forms the leech of the sail. 
     In one embodiment, in the second condition the aft edge of the movable section forms at least part of the leech of the sail. 
     In one embodiment, the movable section translates with respect to the primary section to move between the first and second condition. 
     In one embodiment, the movable section rotates with respect to the primary section to move between the first and second condition. 
     In one embodiment, the movable section rotates rotate about a pivot point near the head of the sail. 
     In one embodiment, the movable section rotate about a pivot point near the foot of the sail. 
     In one embodiment, the primary section comprises flexible regions at its leech that is configured to flex to allow the movable section to pass intermediate the sides of the primary section through the primary section leech. 
     In one embodiment, the movable section is a soft sail. 
     In one embodiment, the movable section is an aerofoil wing sail. 
     In one embodiment, the aft edges of a sail section form a leech when not spread laterally apart by an adjacent sail section. 
     In one embodiment, the aft edges of a sail section overlap with the adjacent section to form a join comprising a substantially continuous surface between the sections adjacent each other when spread apart by the adjacent sail section. 
     In one embodiment, the joins bridge adjacent sections so as to form a substantially continuous surface between adjacent sail sections. 
     In one embodiment, the sail comprises two or more movable sections. 
     In one embodiment, the sail comprises the movable section and a second movable section. 
     In one embodiment, the second movable section nests within the movable section, in a similar configuration to how the movable section nests within the primary section. 
     In one embodiment, at least a portion of the movable section leech is configured to allow at least a portion of the second movable section to pass therethrough. 
     In one embodiment, each sail section has a sail area greater than the sail section aft of it. 
     In one embodiment, the sail comprises a mechanism to actuate the movable sections between their first and second conditions. 
     In a further aspect the present invention relates to a reconfigurable wing sail for a yacht, the wing sail having an adjustable effective sail area by extending or retracting a nested wing sail section through the leech of a primary wing sail section. 
     In one embodiment, the nested wing sail section nests within a cavity of the primary wing sail section. 
     In one embodiment, the area towards and along the leech of the primary wing sail section is flexible to allow the nested wing sail to pass therethrough. 
     In one embodiment, there are multiple nested wing sail sections within the primary wing sail section configured to extend the effective sail area of the sail. 
     In one embodiment, the primary wing sail section is attached to a yacht. 
     In one embodiment, the primary wing sail section comprises a mast. 
     In a further aspect the present invention relates to a yacht comprising the sail described above. 
     In a further aspect the present invention relates to a yacht comprising a sail, the sail comprising at least two sail sections and a primary section having a cavity intermediate port and starboard face sides which converge to form at a leech or head of the primary section, and at least two movable sections moveable between a first condition where the movable sections are enveloped or partially enveloped in the cavity, and a second condition where at least a portion of at least one movable section extends from the head or leech out of the cavity of the primary section, where in the second condition the movable section adds to the effective sail area of the sail. 
     In one embodiment, the moveable sections move vertically out of the head primary section that acts as boom, or from move out from the leech of a mast or wing sail. 
     In one embodiment, the head and/or leech of said primary section and/or one or moveable sections is flexible to allow moveable sections to pass through. 
     In one embodiment, the primary section forms at least part of an aerofoil wing shape in either one or both of the first and second condition. 
     In one embodiment, the yacht comprises mechanisms to actuate the moving of the one or more movable sections. 
     In one embodiment, the yacht extends its effect sail area by moving a moveable section at least partially out of the primary section. 
     Other aspects of the invention may become apparent from the following description which is given by way of example only and with reference to the accompanying drawings. 
     As used herein the term “and/or” means “and” or “or”, or both. 
     As used herein “(s)” following a noun means the plural and/or singular forms of the noun. 
     The term “comprising” as used in this specification means “consisting at least in part of”. When interpreting statements in this specification which include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present. Related terms such as “comprise” and “comprised” are to be interpreted in the same manner. 
     The entire disclosures of all applications, patents and publications, cited above and below, if any, are hereby incorporated by reference. 
     This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth. 
    
    
     
       FIGURE DESCRIPTIONS 
       The invention will now be described by way of example only and with reference to the drawings in which: 
         FIG.  1   : shows a side schematic view of a nestable wing sail in an extended condition. 
         FIG.  2 A : shows a side schematic view of a nestable wing sail in a retracted condition. 
         FIG.  2 B : shows a top schematic view of  FIG.  2 A . 
         FIG.  3 A : shows a top schematic view of a wing sail in a retracted condition. 
         FIG.  3 B : shows a top schematic view of a wing sail in an extended condition. 
         FIG.  4 A : shows a rear perspective view of a wing sail in a retracted condition. 
         FIG.  4 B : shows a rear perspective view of a wing sail in an extended condition. 
         FIG.  5   : shows a rear view of a wing sail in an extended position. 
         FIG.  6   : shows a top schematic view of a wing sail in the extended condition, whereby the moveable section can pivot. 
         FIG.  7 A : shows a top schematic view of a wing sail with the moveable section fully retracted within the primary section. 
         FIG.  7 B : shows a top schematic view of a wing sail with the moveable section partially extending out of the fore section. 
         FIG.  7 C : shows a top schematic view of a wing sail with the moveable section fully extending from the fore section. 
         FIG.  8   : shows a side schematic view of an alternative wing sail, where the moveable section translates from the fore section. 
         FIG.  9 A : shows  FIG.  8 A  extended. 
         FIG.  9 B : shows a top schematic view of a wing sail of  FIG.  9 A . 
         FIG.  10 A  shows a side schematic view of an alternative embodiment of a nestable wing sail with a furling moveable section. 
         FIG.  10 B : shows a top schematic view of  FIG.  10 A . 
         FIG.  10 C : shows an extended condition of  FIG.  10 A . 
         FIG.  10 D : shows a top schematic view of  FIG.  10 C . 
         FIG.  11 A : shows a side schematic view of a nestable wing sail with two moveable sections. 
         FIG.  11 B : shows a top schematic view of  FIG.  11 A . 
         FIG.  12 A : shows a side schematic view of a nestable wing sail of an alternative embodiment where the moveable section is actuated out via a sail boom. 
         FIG.  12 B : shows an extended view of  FIG.  12 A   
         FIG.  13 A : shows a side schematic view of a nestable wing sail of an alternative embodiment where the moveable section slides down and aft to its extended condition. 
         FIG.  13 B : shows an extended view of  FIG.  13 A . 
         FIG.  14 A : shows a side schematic view of a nestable wing sail of an alternative embodiment where the sail has a gap intermediate the moveable section and the primary section. 
         FIG.  14 B : shows a top schematic view of  14 A. 
         FIG.  14 C-E : shows a top schematic view of the sail of  FIG.  14 A , showing the moveable section retracting into the primary section. 
         FIG.  15 A-C : shows a rear top schematic view of a sail extending from a mast or wing sail. 
         FIG.  16 A-C : shows a rear top schematic view of a sail extending from a boom. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to the above drawings, in which similar features are generally indicated by similar numerals, a sail according to a first aspect of the invention is generally indicated by the numeral  10 . 
     In one embodiment now described, there is provided a nestable wing sail  10  configured to be used on a yacht  2 . The yacht having a hull  3 , and the wing sail optionally attached to the hull via a mast  4 . Alternatively, the mast may be integral with the wing sail. The wing sail is preferably of an aerofoil shape, and is formed from skins that create the sides of the wing sail, and the surfaces to be the effective sail area. In one embodiment, the wing sail is formed between the mast and a boom. 
     The sail  10  comprises a primary, or forward section, from which two or more moveable sections are able nest within. The primary section comprises a cavity  109 , for the moveable sections to nest. The cavity  109  may be formed within one or more or the wing sail  10 , mast  4 , and boom. The moveable section can be fully or partially nested within one or more of the wing sail  10 , mast  4 , and boom  18 . The primary section may be said to comprise one or more or the wing sail, mast, and boom. The moveable sections are able to extend out from the cavity  109 , and aft through the leech  102 . There may be multiple moveable sections able to nest within the primary section. Moveable sections may be described as first, second and third moveable sections and so forth. The primary section  100  (as shown in  FIG.  1   ) houses the moveable sections. The primary section may include the mast  4  and/or boom  18   
     Moving of the moveable sections aft from the primary section allows the sail  10  to increase its effective sail area. To reduce the sail area, the moveable sections are retracted back into their adjacent and forward sections, from their extended position. 
       FIG.  3 B  shows a primary section  100  having a first moveable section  200  extending from the primary section  100  leech  102 . The leech  102  is formed from each aft edge  107  of each side  108  of the primary section  100  (as shown in  FIG.  3 A-B ). 
     In the embodiment shown in  FIG.  1 A , the first moveable section  200  extends out from the leech  102  about a pivot point  14  located near the head  103  of the primary section  100 . As the first moveable section  200  extends aft from the primary section  100 , the primary section aft edges  107  becomes a cover or join  11  intermediate the primary section  100  and the first moveable section  200 . The leech  202  of the first moveable section  200 , then becomes the leech of the sail  10 . 
     Alternatively, the first moveable section  200  (and optionally subsequent movable sections) extend out vertically from the boom  18 /head  103 /head  103  etc. I.e. the wing  10  can extend vertically up from the boom, and subsequent sections.  FIG.  15   a - c    shows an example of this. The head of the boom, moveable section, and/or primary section is preferably flexible to allow nested sections to pass through. Preferably the boom comprises all nested sections in a cavity  109  when the sail is in a retracted position. The boom  18  in one embodiment can take on an aerofoil type shape, either in the first or second condition. 
       FIG.  1 B  shows the first moveable section  200  nested within the primary section  100 . The leech  102  of the primary section  100  is the leech of the sail  10 . 
     The embodiments shown in  FIGS.  1  &amp;  2    are just one embodiment of an extendable nested wing sail. The embodiment shown in  FIGS.  1  &amp;  2    shows a rotating moveable section  200 . Other embodiments may be used and fall within the scope of invention, such as embodiments shown in  FIGS.  8  &amp;  9    where a translating moveable section  200  is used. In further embodiments, such as in  FIG.  10   , an unfurling moveable section  200  is utilised to extend the surface area of a wing sail. This will be described in further detail later. 
     There may be multiple extending sections that can be nested within the primary section  100 .  FIGS.  11 A &amp;  11 B  show a sail with two moveable sections  200  and  300 . Again, these moveable sections  200 ,  300  may translate from the primary section  100 , or they may rotate about a pivot point from their adjacent forward section, or both may rotate about the primary section (not shown), or they may utilise a combination or translation and rotation. 
       FIGS.  3 A &amp;  3 B  show details of a simplified cross section of the embodiment of  FIGS.  1  &amp;  2   . It can be seen that the aft edges  107  of the leech  102  of the primary section  100  are able to open up to allow the first moveable section  200  to pass therethrough. 
       FIGS.  4 A,  4 B &amp;  5    show a perspective view of the embodiment of  FIG.  1   , and show that the trailing edges  107  or leech  102  of the primary section  100  open up and allow the moveable section  200  to pass through. 
       FIG.  6    shows an embodiment where the first moveable section or any of the trailing sections are able to trim or rotate with respect to the primary section, and/or their adjacent sections. This allows the wing sail  10  to be better configured for the wind/sailing conditions. 
       FIGS.  7 A-C  show a sail  10  that has a nested section that is able to be partially extended out from the primary section  100 . This allows a graduation of configurations between a fully retracted and a fully extended condition of the sail  10 . This partial extension can be used in any of the embodiments as described herein. 
       FIGS.  7 A-C  also show the moveable section  200  being able to pivot about a point  12  to trim the sail. There may be multiple moveable sections that are able to trim. This trimming configuration may be used in any of the embodiments as described herein. 
       FIGS.  8  &amp;  9    show the retracted and extended configurations of a translating moveable section  200 .  FIGS.  8  &amp;  9    show a translating nested section  200  that translates from the trailing edge or leech  102  of the primary section  100 . An extension mechanism  15  and a retraction mechanism  16  is used to extend and retract the one or moveable sections. 
     In the most basic form the extension mechanism  15  is a rope or other flexible member, such as wire, in combination with one or more pulleys  17  that allows pulling of a rope at one end to extend the first moveable section  200  from the primary section  100 . As shown in  FIG.  8   , a retraction mechanism  16  is a rope attached to the foot  104  of the moveable section  200 , so the moveable section  200  is able to be pulled towards the bow of the boat, to nest inside the primary section  100 . 
     There may be numerous extension and retraction mechanisms configured and designed to allow optimum or desired extension and retraction of the nested sections. An alternative rope and pulley system is shown in  FIG.  12 A-B , where a boom  18  is utilised to locate a pulley  17  at its distal end. This allows a rope to pull out a moveable section towards the distal end of the boom  18 . 
     There are many other extension and retraction mechanisms that could be utilised with the present invention. Some examples are linear actuators which are, for example, hydraulic or electric powered. 
       FIGS.  10 A-D  show a further embodiment of the invention, wherein the nested section  200  is a single “soft” or “2D” sail. The soft moveable section  200  is configured to be unfurled about a roller  13  to extend it outwards from the leech  102 . This is a more simplified design, wherein the leech  102  does not need to extend laterally as much to allow the soft moveable section  200  to pass therethrough, compared to a wing moveable section. The soft sail may be stored in said cavity  109  within the mast or boom. 
       FIGS.  13 A-B  show a further embodiment, where the moveable section  200  is configured to slide/translate downwards towards its extended condition as shown in  FIG.  13 B . The moveable section  200  is configured to slide along tracks  19  (not all shown) to move between a retracted and extended condition. This embodiment allows the movable section  200  to be gravity assisted towards its extended condition. A simply halyard system attached to the moveable section  200  may be used to retract the moveable section  200  back into the primary section  100 . This is just one embodiment of a tracked system, there may be many different configurations and track patterns appropriate for different sail types, and designs. For example, less steep tracks, tracks that utilise hydraulics to move the moveable sections  200  etc. 
       FIGS.  14 A-E  show a further embodiment of the present invention where the aerofoil shape of the moveable section  200  fully extends out of the aerofoil shape of the primary section  100 . This configuration allows air flow intermediate the leech  102  and the luff  201  of the moveable section  201 . This configuration of a gap seen, often seen intermediate a trim tab and main section is known in existing wing sails. However, this trim tab has not previously been able to be retracted into a forward sail section, or been able have its effective sail area removed from the overall effective sail area. 
     The moveable section  200  seen in  FIG.  14    may be able to pivoted about an axis so as to allow differing wing shapes. 
     The leech  102  may be configured to allow easy entry of the movable section  200  back in to the primary section  100 .  FIG.  14 C  shows the upturned edges of the leech  102  that allow the movable section  200  to start entering into the leech  102 . This is required, as in other embodiments where the movable section stays keeps the leech  102  open, in the  FIG.  14    embodiment the leech  102  is allowed to close back in on itself. And thus, a configurations such as a upturn at each leech edge is utilised to allow the movable section  200  to start entering into the leech  102   
     The leech opening, for all embodiments, it may be of a variety of configurations. In one embodiment, the wing sections may have flexible ribs on each side that are configured to flex outwards so that the aft edge of the wing section, at the leech edge  102 , able to laterally open up to allow movable sections  200  to enter and exit. Flexible ribs (or battens) are well-known in the sailing industry. 
     The leech  102  of a section that is able to laterally open up has aft edges  107  as shown in  FIG.  3 B . 
     In some embodiments the aft edges  107  are substantially stiff so that they are able to be actuated laterally outwards (independent of the respective moveable section) to allow a movable section to pass therethrough. This is an alternative to the movable section itself opening up the aft edges  107 /leech  102  as it passes through. However, in most embodiments, the aft edges that form the leech of a respective section are substantially resilient and flexible so that they follow the outer surface of the respective movable section. 
     Preferably the aft edges  107  are able to form a join  11  as described previously. This join may include or have an integral flexible member that is compliant with the angles between two adjacent sections. The join ideally creates a smooth transition between the sail sections. 
     The aft edges  107  may in some embodiments be biased open (i.e. laterally spread apart), with actuation to close the aft edges  107  to form a leech  102 , in behind the moveable section once it is fully nested within the section that houses it. However, more likely, is that the aft edges  107  are biased closed, and forced to be spread laterally apart by moveable section passing through. 
     Where the leech  102  and aft edges  107  and other features of the primary section are described, it is incorporated in the present invention that the moveable sections that have further nested moveable sections within them, may include the same designs, features and configurations of the primary section. 
     Where in the foregoing description reference has been made to elements or integers having known equivalents, then such equivalents are included as if they were individually set forth. 
     Although the invention has been described by way of example and with reference to particular embodiments, it is to be understood that modifications and/or improvements may be made without departing from the scope or spirit of the invention.