US20150000578A1

US20150000578A1 - Twin asymmetrical wing sail rig

Info

Publication number: US20150000578A1
Application number: US14/306,394
Authority: US
Inventors: Matthew Brent Strebe; Eric Samuel Weiner
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-06-18
Filing date: 2014-06-17
Publication date: 2015-01-01

Abstract

The problems associated with rotating a wing sail around a stayed rig mast; changing the airfoil shape of a wing sail on different tacks; and reefing a wing sail may be solved by using an A-frame mast with port and starboard mast extrusions for supporting two asymmetrical wing sails.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent Application No. 61/836,523 filed on Jun. 18, 2013, titled: TWIN ASYMMETRICAL WING SAIL RIG, and all the benefits accruing therefrom under 35 U.S.C. §119(e), the entire disclosure of which is hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention is in the field of sailing rigs and more particularly, is in the field of twin asymmetrical wing sailing rigs.

BACKGROUND OF THE INVENTION

Sailing rigs have existed for thousands of years. A typical sailing rig includes an elongated, oval-shaped fixed mast, which is held in place by a plurality of stays, turnbuckles and shackles. The mast supports the sail and boom, which creates the driving force to propel a craft across the water when the wind blows. However, traditional masts for sailboats are not aerodynamic and can act as an obstacle to airflow resulting in high drag and reduced efficiency of the sailing rig.
Wing sails have been developed to overcome the problems of a traditional mast. A wing sail is simply a wing (like an aircraft wing), that is used as a main sail instead of a traditional yardage sail. Wing sails offer several advantages: they can generate lift from as little as 8 degrees off the wind - vastly better pointing than a traditional sail. Their efficiency of lift generation is also constant at all wind headings. This means that they range from 25% more efficient (more thrust) on a beam reach to 400% more efficient when pointing. They also generate less drag and less heel and therefore, generate more thrust or lift for propelling a craft. Heeling can be easily controlled with minor changes to the angle of attack of a wing sail. The efficiency of a wing sail comes from imparting much of the force that would have been lost to heeling into lift.
Sailing a wing sail craft consists simply of rotating the wing sail to point at about 10 degrees off the apparent wind. This is easily accomplished by loosening the sail, letting it settle on the apparent wind, and then sheeting it in about 10 degrees (or to whatever the optimal angle of attack for the aerodynamic profile and wind conditions happens to be). Conversely, a wing sail craft can be slowed or depowered by reducing the angle off the wind. Wing sails are excellent in high winds as long as the wind is constant. Wing sails can be made to automatically find the optimal angle of attack with a “tail wing” (exactly like an aircraft tail wing), which pushes the main wing sail ten degrees off the apparent wind. With this rig and proper balance, it is not necessary to control the rig to gain optimal forward thrust.
One of the disadvantages of a wing sail is that the supporting rigid mast structure is heavy. In addition, the rigid mast structure cannot be reefed in heavy winds. When overpowered, a wing sail craft can be pointed into the wind to stall it but that creates drag, which instantly converts to heel and can knockdown a boat (the wing sail AC45 Catamarans are knocked down routinely because of this effect). Alternatively, a wing sail can be loosened and allowed to flap (called feathering), which is safe for the craft but can destroy the rigid structure of the wing sail. Neither option is ideal.
Symmetrical wing sails (wings where both sides are the same shape and therefore, are effective on both tacks) generate only marginally more lift than a traditional sail. Wing sails need to be asymmetrical (like an airplane wing, where the top surface is more curved than the bottom) to have a dramatically higher coefficient of lift than a traditional sail. When changing from a port tack to a starboard tack, the shape of a single wing must be inverted. Changing the shape of a wing sail from a port tack to a starboard tack requires a lot of internal mechanisms, which adds a significant amount of weight to the sail and can easily break.
Accordingly, there remains a need in the art for new and improved sailing rigs for wing sails.

SUMMARY OF THE INVENTION

The present invention addresses these needs and more by providing new methods and devices for twin asymmetrical wing sails.
Thus, in one embodiment the invention provides a sailing rig having a fore and aft-stayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the port and starboard mast extrusions each support one of the two asymmetrical wing sails.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the port and starboard mast extrusions are directly joined together at about the pinnacle and center of effort of a sailboat, and wherein the port and starboard mast extrusions are supported by tabernacles.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the port and starboard mast extrusions are joined by a horizontal bar near their apex, and wherein the port and starboard mast extrusions are supported by tabernacles.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the port and starboard mast extrusions are stepped at the port and starboard stay chainplates.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the port and starboard mast extrusions are made of aluminum, carbon fiber or other composite material.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the port and starboard mast extrusions are rounded tubes of aluminum, carbon fiber or other composite material.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the port and starboard mast extrusions are fixed in place.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the port and starboard mast extrusions are rotatable in order to provide rotation to the asymmetrical wing sails.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the two asymmetrical wing sails can collapse accordion-style, such that the unused wing is lowered when not in use.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the two asymmetrical wing sails are complimentary to provide optimal wing shape for a port or a starboard tack.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the two asymmetrical wing sails include a plurality of asymmetrical airfoil shaped ribs, each rib having a front or leading edge and a back or trailing edge.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the asymmetrical airfoil shaped ribs have a S1223 wing profile.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein a stack of asymmetrical airfoil shaped ribs are attached to a sail material at an interval that allows the asymmetrical wing sails to maintain its asymmetrical wing shape.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the asymmetrical airfoil shaped ribs include a plurality of openings or holes for encircling the port or starboard mast extrusion.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the plurality of openings or holes in the asymmetrical airfoil shaped ribs are located from about 20-30% from the front or leading edge of the asymmetrical airfoil shaped rib.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the plurality of openings or holes in the asymmetrical airfoil shaped ribs have the same shape as the port and starboard mast extrusions, and which the asymmetrical wing sails can be raised or lowered.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the port and starboard mast extrusions are rounded and are fixed in place, and the asymmetrical airfoil shaped ribs of the asymmetrical wings rotate freely around the port and starboard mast extrusions.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein the port and starboard mast extrusions are not rounded and the asymmetrical airfoil shaped ribs of the asymmetrical wings rotate in unison with the port and starboard mast extrusions.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, further including a slat having a ribbon of sailcloth attached to and in front of the leading edge of the asymmetrical wing sails.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, wherein a top rib takes the role of a gaff in a gaff-rigged sailboat; and the bottom rib takes the role of a boom in a traditional Bermudan rig sailboat.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, where the rotation of the ribs is controlled by one or more mainsheets.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, where the rotation of the ribs is controlled by one or more aerodynamic tail wings.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, where the rotation of an individual rib or set of ribs may be separately controlled by a tail-wing to provide differing angles of attack at different elevations along the wing.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, where the rotation of the mast and ribs is controlled by one or more mainsheets.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, where the rotation of the mast and ribs is controlled by a lever such as a bar or tiller.
In another embodiment the invention provides a sailing rig having a fore and aftstayed A-frame mast with port and starboard mast extrusions; and two asymmetrical wing sails, where the rotation of the mast and ribs is controlled by automated actuators of any type.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the present invention will become more apparent with reference to the following description taken in conjunction with the accompanying drawings wherein like reference numerals denote like elements and in which:

FIG. 1 is a view of a stayed A-frame mast with port and starboard mast extrusions and two asymmetrical wing sails; and

FIG. 2 is a view of an asymmetrical rib having a S1233 profile, and with a plurality of openings or holes for encircling the port or starboard mast extrusions of a stayed A-frame mast.

DETAILED DESCRIPTION OF THE INVENTION

Unless otherwise defined, all technical terms used in connection with the disclosure shall have the meanings that are commonly understood by those of ordinary skill in the art. Further, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.
There are at least three major engineering problems with a traditional wing sail. First, there are no mechanisms for rotating a wing sail 360 degrees around a stayed rig. Unstayed rigs can be used for wing sails but they need to be stronger and are made of very expensive exotic materials. For an unstayed rig, the foot of the mast must rotate without moving side to side, which is complex, prone to shock-loading damage, and the resulting mechanisms are very heavy and expensive. In addition, the mechanism to change the airfoil shape of a wing sail to the opposite side when changing tacks requires a lot of internal mechanisms, which adds weight to the sail and can easily break. The airfoil shape of a wing sail has to be ideal or the lift characteristics are greatly diminished. Wing sails are notoriously finicky: a simple crease or ridge can destroy laminar flow across the sail, which greatly diminishes much of their advantages. This is why traditional sails have persisted for so long: they don't have a “works/doesn't work” failure mode that a wing sail does. Finally, the lack of a simple mechanism for reefing a wing sail when necessary in heavy winds, as well as for storing and trailering the craft makes wing sailboats impractical.
It has been discovered that the problems associated with rotating a wing sail around a stayed rig mast; changing the airfoil shape of a wing sail on different tacks; and reefing a wing sail may be solved by using an “A-frame” mast with port and starboard mast extrusions for supporting two wing sails.
FIGS. 1 and 2 illustrate an embodiment of the twin asymmetrical wing sail rig, in which the following chart summarizes the nonlimiting components of the twin asymmetrical wing sail rig:
A-frame mast (10);
Two asymmetrical wing sails (12 and 14);
Port and starboard mast extrusions (16 and 18);
Point or pinnacle (20);
Sailboat (22);
Forestay (24);
Aftstay (26);
Asymmetrical airfoil shaped rib (28);
Front or leading edge of rib (30);
Back or trailing edge of rib (32);
Opening or hole in rib (34);
Arc (36);
Four standoffs (38);
Slat (40);
Holes in rib for a downhaul halyard pass-through (42 and 44); and
Holes in rib to save weight (46).
As shown in FIG. 1, instead of a traditional stayed rigged mast, a stayed A-frame mast (10) can be used to support two asymmetrical wing sails (12 and 14). The A-frame mast (10) includes port and starboard mast extrusions (16 and 18), which may be directly joined together at a pinnacle (20) above a sailboat (22) at the center of effort as shown. Alternatively, the port and starboard mast extrusions (16 and 18) may include a horizontal bar, which joins them together for support near their apex (not shown). The port and starboard mast extrusions (16 and 18) may be stepped at the location of the port and starboard stay chainplates (24 and 26) as found on a typical stayed sailboat rigging, and meet at a point or pinnacle (20) above the deck approximately as high as the sailboat (22) is long. The two asymmetrical wing sails (12 and 14) can be made so they collapse accordion-style, such that the unused asymmetrical wing (12 or 14) is lowered when not in use. The collapsible asymmetrical wing sails (12 and 14) can be easily reefed or stowed for storing or trailering. In addition, the two asymmetrical wing sails (12 and 14) can be made so they are complimentary to each other, which allows for use of the optimal wing shape for port and starboard tacks.
The port and starboard mast extrusions (16 and 18) of the A-frame mast (10) can be of any shape or size, and can be made of any appropriate materials including aluminum, carbon fiber, and other well known composite materials in the art. At or near the pinnacle (20) of the A-frame mast (10), a custom crossbar may be used to join the port and starboard mast extrusions (16 and 18) together, and which may include a halyard block (not shown) attached for each port and starboard mast extrusions (16 and 18). The port and starboard mast extrusions (16 and 18) may be simple rounded tubes and may be fixed in place. Alternatively, the port and starboard mast extrusions (16 and 18) may be non-rounded and may be rotatable in order to provide rotation to the two asymmetrical wing sails (12 and 14). Due to their simplicity, the combined port and starboard mast extrusions (16 and 18) weigh about the same amount as a single mast on a typical sailboat. The A frame mast (10) may be stayed with a typical forestay (24) and aftstay (backstay) (26) assembly at the center of the pinnacle (20) or crossbar. The port and starboard mast extrusions (16 and 18) act to support the two asymmetrical wing sails (12 and 14) and replace the function of the mast and side stays in a traditional sailing rig.
The port and starboard mast extrusions (16 and 18) of the A-frame mast (10) may each be supported by a tabernacle (32 and 34). The tabernacles (32 and 34) may be from about 1-2 feet high, and are fixed and non-rotating, and generally have the same profile as the port and starboard mast extrusions (16 and 18). When an asymmetrical wing sail (12 or 14) is completely lowered, it rests on its tabernacle (32 or 34) and can be secured or locked into place. A specially engineered joint that can rotate 360 degrees and bend from 0 to 90 degrees forward can be used to join a tabernacle (32 or 34) to its port or starboard mast extrusion (16 or 18).
The A-frame mast (10) includes two asymmetrical wing sails: port (12) and starboard (14). Each asymmetrical wing sail (12 and 14) is complimentary to each other, never changes its shape and is perfectly shaped for its port or starboard tack. The port asymmetrical wing (12) is used on a port tack and the starboard asymmetrical wing (14) is used on a starboard tack. Any asymmetrical profile with good lift characteristics will do for the asymmetrical wing sails (12 and 14), and includes but is not limited to the S1223 wing profile.
The mechanism for changing the shape of a wing sail for each tack is to change the asymmetrical wing sail (12 or 14) being used. The problem of 360 degree rotation with stayed rigs is solved by having two asymmetrical wing sails (12 and 14). Each asymmetrical wing sail (12 and 14) needs only to rotate about 160 degrees to produce the desired range of motion (Irons doesn't matter, and downwind is wing-on-wing). Because each asymmetrical wing sail (12 and 14) needs to rotate only about 160 degrees, they do not impact the forestay (24) and aftstay (26) of the A-frame mast (10). The rotation occurs on the port and starboard masts extrusions (16 and 18), which are inherently out of the way of the forestay (24) and aftstay (26).
The two asymmetrical wing sails (12 and 14) include a plurality of asymmetrical airfoil shaped ribs (28), each rib (28) has a front or leading edge (30) and a back or trailing edge (32), and which forms the two dimensional section of each wing sail (12 and 14). Each rib (28) may be made of any appropriate material including but not limited to wood, polymeric resins, carbon fiber composites and the like. As shown in FIG. 2, each asymmetrical rib (28), here a rib (28) having a S1223 wing profile, includes a plurality of openings or holes (34) for encircling the port or starboard mast extrusion (16 and 18) of the A-frame mast (10). Each of the ribs (28) include the opening or hole (34) located from about 20-30% from the front or leading edge (30) to the back or trailing edge (32) of the asymmetrical airfoil shaped rib (28), and has about the same shape as the port and starboard mast extrusions (16 and 18). It is through this opening or hole (34) that each of the ribs (28) slides on the port and starboard mast extrusions (16 and 18) and the two asymmetrical wing sails (12 and 14) can be raised or lowered. In some embodiments, the opening or hole (34) may be located from about 20-25% from the front or leading edge (30) to the back or trailing edge (32) of the asymmetrical airfoil shaped rib (28), and in other embodiments, the opening or hole (34) may be located from about 23% from the front or leading edge (30) to the back or trailing edge (32) of the asymmetrical airfoil shaped rib (28). The port and starboard mast extrusions (16 and 18) may be tubes or spars of aluminum, carbon fiber, or other well known composite materials, and the two asymmetrical wing sails (12 and 14), each having a series of airfoil shaped rib structures (28), slide up and down on it. With a rounded port and starboard mast extrusions (16 and 18), the ribs (28) rotate freely while the mast extrusions (16 and 18) are fixed in place. With any other non-rounded port and starboard mast extrusion (16 and 18) profile, when the mast extrusion (16 and 18) rotates—all the ribs (28) and the asymmetrical wings (12 and/or 14) rotate.
The asymmetrical airfoil shaped ribs (28) may include an arc (36) on the four standoffs (38) at the front or leading edge (30), which supports a slat (40). The opening or hole (34) may be squared for use with squared port and starboard mast extrusions (16 and 18). The opening or hole (34) may be rounded if the port and starboard mast extrusions (16 and 18) are rounded. The two smaller holes (42 and 44) next to the square opening or hole (34) are the downhaul halyard pass-through. The remaining holes (46) in the ribs (28) are to save weight.
A stack of the asymmetrical airfoil shaped ribs can be sewn (tacked or stapled) onto typical wing sail material at an interval that allows the material to maintain the wing shape in heavy winds. For example, about 1-2 foot intervals can be used. When the top rib is held aloft, an asymmetrical wing structure is created by the sailcloth under tension with ribs at every 1-2 feet. The top rib may be stronger and takes the role of a gaff in a gaff-rigged sailboat; and the bottom rib may be stronger and takes the role of the boom in a traditional Bermudan rig sailboat.
When made of ½ inch marine plywood, each rib should weigh about 6 lbs., and the asymmetrical wing structural components will add considerable weight aloft compared to sailcloth alone. This shouldn't be a problem given the much reduced heeling inherent with a wing sail, but depending on the weight it may be necessary to add a small amount of additional permanent ballast to the keel of the boat to compensate for weight aloft compared to a traditional Bermudan rig.
At the front or leading edge of the asymmetrical airfoil shaped ribs, an exterior (outside the Mylar) standoff protrudes forward, and another ribbon of sailcloth may be attached to this, which goes in front of the leading edge. This creates the slat, which can dramatically improve the efficiency of the lift generated and increase the “angle of attack,” or the range of angles at which the asymmetrical wing sail will work up to about 30 degrees. This means a lot less sail handling in confused winds.
When the halyards are loosened, the asymmetrical wing sail assembly collapses down accordion-style onto the deck, tabernacle and around the base of the port and starboard mast extrusions like a sock that has been pushed or pulled down. When hoisted, the ribs slide up the port or starboard mast extrusions, and when tensioned, the asymmetrical wing sail becomes rigid. The boom rib, interior ribs, and gaff rib provide the wing sail shape in two dimensions, and the tensioned sail fabric provides the shape of the wing sail in the third dimension.
The mechanism for reefing an asymmetrical wing sail is simple. By loosening the halyards, the ribs in the wing sail slide down the port and/or starboard mast extrusion until they are stacked at the bottom. To control the downhaul more precisely, a downhaul line can be ran through the interior ribs from the bottom to the top, with a stopper knot above the top rib. Loosening the halyards and hauling the downhaul line will then pull the asymmetrical wing sail to the deck faster.
To tack an asymmetrical wing sail craft, downhaul the windward wing to the deck, and hoist the leeward wing. Because the wing sail is technically a gaff rig with the top rib acting as the gaff, two halyards are necessary per wing (four total) in order to tension the rig properly. To simplify rigging, the halyards can be run through the center of port and starboard mast extrusions, with blocks at the top to direct them to the leading and trailing edges of the gaff wing rib. A single downhaul should suffice, as tension is not a factor in downhaul. At the foot of the two mast extrusions, the halyards can be turned with blocks to run back to the cockpit clutches on each side. Both halyards can be hauled at the same time, but they will have to be separately tensioned when the wing is fully aloft.
This does mean that tacking can be a little complicated. However, the dramatic improvement in pointing and downwind performance means that tacking should be far less necessary. Most headings can be reached directly without ever tacking.
When the mast extrusion is rotated (as per usual) and the asymmetrical wing sail is lowered, it will not fit over the non-rotating tabernacle until the wing is brought to the fore-aft position. This can be done after the asymmetrical wing has been completely lowered, and after the other wing sail has been lofted so as not to complicate tacking. By keeping the leading and trailing mainsheets cleated while lowering, the lowered wing will not move during the tack operation and can be rotated into place onto the tabernacles when time permits after the tack is complete.
There are two types of asymmetrical wings: wings with fixed rounded mast extrusions around which the wing ribs rotate; and wings with non-rounded mast extrusions where the mast extrusion and the wing ribs rotate together. They are trimmed differently.
For fixed rounded mast extrusions, trim is controlled by a tail-wing in exactly the same manner as an airplane: A pole comes out the back of some or all of the ribs and goes back a sufficient distance to create leverage on the ribs. Typically, a distance of about 8 feet may be used. Attached to the end of this pole is a tail wing using an appropriate wing profile such as NACA0012. The wind on the tail wing causes it to center the tail wing to the wing and push the main wing with leverage to whatever angle the poles are off of the center of lift. These wings are auto-trimming and will always maintain the fixed angle of attack created by the tail pole angle, and will automatically turn into the wind. There need be no mechanism needed to control trim. Furthermore, every individual rib may have its own separate tail wing, allowing the wing to “twist” such that the angle of attack varies for each rib so as to be perfect for the wind at its elevation, rather than the entire wing maintaining a common angle of attack.
For asymmetrical wings with rotating masts extrusions and non-rounded profiles, wing rotation is controlled at the boom (bottom rib) with a leading edge sheet and a trailing edge sheet. Loosen both sheets and allow the wing to come to the wind. Haul in the trailing edge sheet (analogous to the mainsheet) until the wing is back ten degrees (or whatever the optimal angle of attack for the wing foil design happens to be), and the sail powers up. Cleat it off, then harden up and cleat off the leading edge sheet. A yang can be used to downhaul on the boom rib to keep the sail taut, but it is not necessary to adjust it for sail shape.
No headsail is necessary with the asymmetrical wing sail rig. A roller-furling 75% jib could be used with the sheets going inside the masts, but there would be little point to it as the wing sails don't suffer from weather helm. This jib would auto-tack as there's nothing in its way. A jib might be useful to create a slat effect.
A symmetrical spinnaker could be used for downwind sailing, but the wing-on-wing configuration of both asymmetrical wings would present more area directly to the wind, likely making all headsails unnecessary.
The lift for the asymmetrical wing sails may be calculated using the following values: Cl=2.5, p=1.225 (standard sea level), V=7.7 (15 knot wind), A=18 square meters of sail. A coefficient of lift of 2.5 is conservative for an asymmetric wing airfoil: Cl as high as 4 can be achieved. At a Cl of 3, a 26′ sailboat would be sailing at the speed of the apparent wind on any point of sail excepting irons, which would only be 20 degrees wide. Performance would be about double what it is with a typical Bermudan rig, which is to say that any given speed could be accomplished with half the wind speed and considerably less heeling.
Lowering the A-frame mast for trailering is simple. The bases of the port and starboard mast extrusions may be fixed in place, and the asymmetrical wing sails can be reefed down onto these lower sections (right to the deck) when lowered. They each form a sail pack about 2 feet high. These may be called tabernacles. This is the permanent storage location for the wing sails—they never have to be removed from the mast base. These tabernacles may be completely vertical, and the A frame mast may start at the hinge location.
At about the 2 foot height where the tabernacle meets the mast there is a “knee” hinge that allows the A frame to lower forward over the bow of the boat. This will protrude approximately ⅓ the length of the boat forward of the bow, and therefore likely over the tow vehicle depending upon size. This will not present an issue when towing.
Although the disclosure has been described with reference to the above examples, it will be understood that modifications and variations are encompassed within the spirit and scope of the disclosure. Accordingly, the disclosure is limited only by the following claims.

Claims

What is claimed is:

1. A sailing rig comprising a fore and aftstayed A-frame mast having port and starboard mast extrusions; and two asymmetrical wing sails, wherein the port and starboard mast extrusions each support one of the two asymmetrical wing sails.

2. The sailing rig of claim 1, wherein the port and starboard mast extrusions are directly joined together at about the pinnacle and center of effort of a sailboat, and wherein the port and starboard mast extrusions are supported by tabernacles.

3. The sailing rig of claim 1, wherein the port and starboard mast extrusions are joined by a horizontal bar near their apex, and wherein the port and starboard mast extrusions are supported by tabernacles.

4. The sailing rig of claim 1, wherein the port and starboard mast extrusions are stepped at the port and starboard stay chainplates.

5. The sailing rig of claim 1, wherein the port and starboard mast extrusions are made of aluminum, carbon fiber or other composite material.

6. The sailing rig of claim 1, wherein the port and starboard mast extrusions are rounded tubes of aluminum, carbon fiber or other composite material.

7. The sailing rig of claim 1, wherein the port and starboard mast extrusions are fixed in place.

8. The sailing rig of claim 1, wherein the port and starboard mast extrusions are rotatable in order to provide rotation to the asymmetrical wing sails.

9. The sailing rig of claim 1, wherein the two asymmetrical wing sails can collapse accordion-style, such that the unused wing is lowered when not in use.

10. The sailing rig of claim 1, wherein the two asymmetrical wing sails are complimentary to provide optimal wing shape for a port or a starboard tack.

11. The sailing rig of claim 10, wherein the two asymmetrical wing sails include a plurality of asymmetrical airfoil shaped ribs, each rib having a front or leading edge and a back or trailing edge.

12. The sailing rig of claim 11, wherein the asymmetrical airfoil shaped ribs have a S1223 wing profile.

13. The sailing rig of claim 12, wherein a stack of asymmetrical airfoil shaped ribs are attached to a sail material at an interval that allows the asymmetrical wing sails to maintain its asymmetrical wing shape.

14. The sailing rig of claim 13, wherein the asymmetrical airfoil shaped ribs include a plurality of openings or holes for encircling the port or starboard mast extrusion.

15. The sailing rig of claim 14, wherein the plurality of openings or holes in the asymmetrical airfoil shaped ribs are located from about 20-30% from the front or leading edge of the asymmetrical airfoil shaped rib.

16. The sailing rig of claim 15, wherein the plurality of openings or holes in the asymmetrical airfoil shaped ribs have the same shape as the port and starboard mast extrusions, and which the asymmetrical wing sails can be raised or lowered.

17. The sailing rig of claim 16, wherein the port and starboard mast extrusions are rounded and are fixed in place, and the asymmetrical airfoil shaped ribs of the asymmetrical wings rotate freely around the port and starboard mast extrusions.

18. The sailing rig of claim 16, wherein the port and starboard mast extrusions are not rounded and the asymmetrical airfoil shaped ribs of the asymmetrical wings rotate in unison with the port and starboard mast extrusions.

19. The sailing rig of claim 13, further comprising a slat comprising a ribbon of sailcloth attached to and in front of the leading edge of the asymmetrical wing sails.

20. The sailing rig of claim 11, wherein a top rib takes the role of a gaff in a gaff-rigged sailboat; and the bottom rib takes the role of a boom in a traditional Bermudan rig sailboat.

21. The sailing rig of claim 17, where the rotation of the ribs is controlled by one or more mainsheets.

22. The sailing rig of claim 17, where the rotation of the ribs is controlled by one or more aerodynamic tail wings.

23. The sailing rig of claim 22, where the rotation of an individual rib or set of ribs may be separately controlled by a tail-wing to provide differing angles of attack at different elevations along the wing.

24. The sailing rig of claim 18, where the rotation of the mast and ribs is controlled by one or more mainsheets.

25. The sailing rig of claim 18, where the rotation of the mast and ribs is controlled by a lever such as a bar or tiller.

26. The sailing rig of claim 18, where the rotation of the mast and ribs is controlled by automated actuators of any type.