US20090151614A1

US20090151614A1 - Sailing craft comprising a tilting rigid sail system

Info

Publication number: US20090151614A1
Application number: US11/955,357
Authority: US
Inventors: Dale William Hanchar
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-12-12
Filing date: 2007-12-12
Publication date: 2009-06-18
Also published as: AU2007249085A1

Abstract

A sailing craft propelled by a tilting sail system comprising an aerofoil sail capable of omni-directional attitude for wind propulsion. The sail is fixed to the craft in such a manner as to permit omni-directional attitude. Sail control means allows the sail placement in a forward propulsion attitude relative to wind direction. The sail is rigid and has an asymmetric shape.

Description

CROSS-REFERENCES TO OTHER APPLICATIONS

N/A

FIELD OF THE INVENTION

This invention pertains to sailing craft, and tilting sail systems and more particularly to a sailing craft comprising a tilting rigid sail system.

BACKGROUND OF THE INVENTION

Sailing craft and sail systems are well known. The idea of putting a rigid aerofoil-type sail on a sailing craft is discussed in U.S. Pat. No. 2,170,914 issued to Rummler and U.S. Pat. No. 1,670,936 issued to M. McIntyre et al. The primary problem associated with these craft and sail systems pertains to “staying” the sails and rigging using cables and rope while allowing active portions to move freely in order to operate properly. As illustrated by U.S. Pat. No. 4,068,607 the cable-based rigging and stay controls are very complicated and difficult for a small crew or single operator to operate.
What is therefore required is a rigid sail system that can be operated with a minimum of stays and rigging by one operator or a small crew.

OBJECTS AND ADVANTAGES OF MY INVENTION

My invention is a novel and ingenious improvement to the present rigid sail systems with the following objectives and advantages:

- 1. The sail shape does not depend on the wind and it maintains a constant curvature regardless of wind speed or direction for maximum generation of thrust;
- 2. The constant sail shape allows the sail craft to be sailed “close to the wind” resulting in quicker tacks, fewer stalls and optimized forward thrust;
- 3. The sail system operates without a boom that swings low amidships;
- 4. The sail system is self-weather cocking to the mast and will turn into the wind automatically;
- 5. The sail system controls are simple and may be confined to a single winch operable by a single operator;
- 6. The sail system permits more sail area than traditional soft sails because the rigid sail system can be angled to reduce heel and has a low centre of effort;
- 7. The control of the heel of the sail craft is accomplished in three ways: through the manipulation of sail tilt, the mainsheet and the rudder;
- 8. The rigid sail system permits the craft to lift from the water and therefore increases speed of the craft by reducing hull drag;
- 9. The rigid sail system offers a simplified control for one operator or a small crew;
- 10. The rigid sail system exemplified herein can be applied to craft of all sizes from toy vessels to large cargo vessels with a varying configuration of hulls, such as, mono and multi hulls;
- 11. The rigid sail system exemplified herein can be operated by computers with wind speed and direction sensors to automatically adjust the sails for optimized thrust. This can save significant fuel costs for commercial vessels; and,
- 12. The large surface area of the rigid sail is adaptable to coverage by flexible photo-voltaic cells permitting power generation for the electrical needs of the craft.

SUMMARY OF THE INVENTION

To overcome the deficiencies in prior art rigid sail systems and accomplish the objectives set out herein, my invention is a sail craft comprising a tilting rigid sailing system. The sail craft has a hull having a bow and a stern, a port side and a starboard side. The tilting sail system comprises a sail comprising an aerofoil member capable of omni-directional attitude for wind propulsion. The aerofoil member is supported by support means for fixing the aerofoil member to the sailing craft and permitting omni-directional attitude. The aerofoil member is controlled by control means for placing the aerofoil member in a forward propulsion attitude relative to wind direction.
The aerofoil member is rigid and has an asymmetric shape and is self weather cocking to the mast.
The aerofoil member comprises a leading edge, a trailing edge, an upper camber, a chord, a span, a centre line, a port side, a starboard side and a chord line. The span is generally greater than the chord. In one example of the invention, the aerofoil member has a first chord at the leading edge and a second chord at the trailing edge. The second chord is larger than the first chord.
In one example of the rigid sail system described herein, the aerofoil member further includes framing means adapted to maintain the asymmetric shape of the aerofoil member. The covering of the aerofoil member may be hard or soft. The aerofoil member support means comprises a vertical mast having a bottom end fixed to the hull of the craft and top end for mounting the aerofoil member. There is also at least one stay member fixed between the vertical mast and the hull to provide stability to the vertical mast.
Aerofoil member control means for placing the aerofoil member in a forward propulsion attitude relative to wind direction comprises means for controlling the attitude of the aerofoil member for optimizing aerofoil inclination and surface area to wind direction. Means for controlling the attitude of the aerofoil member comprises: Swivel and pivot means connecting the second end of the vertical mast to the aerofoil member permitting the aerofoil member to adopt a plurality of desired inclination angles; and, control means for placing and maintaining the aerofoil member to adopt one of the plurality of desired inclination angles.
In one example of my invention described herein the swivel and pivot means comprises: a mounting member fixed to the framing means for mounting the swivel and pivot means to the aerofoil member; damping means fixed to the swivel and pivot means and disposed within the second end of the vertical mast for damping forces induced into the swivel and pivot means by wind; swivel means for permitting the aerofoil member to swivel around the vertical mast; and, pivot means for permitting rotation of the aerofoil member about the chord line.
In another example of my invention described herein the damping means comprises; a first member disposed within the vertical mast proximate to the second end; a damping spring disposed within the vertical mast, wherein the damping spring member has a first end and a second end, and wherein the first end rests upon the base member; a second member disposed within a third member, wherein the second member rests upon the second end of the damping spring member and is adapted to transfer the forces from the swivel and pivot means to the damping spring; and, the third member having a first end adapted to receive the second end of the damping spring and a second end fixed to an axle, wherein the third member is further adapted for telescopic placement within the second end of the vertical mast thereby permitting reciprocating movement of the third member relative to the vertical mast in reaction to the forces.
In another example of the invention described herein, the swivel means comprises the axle attached by the pivot means to the aerofoil member. The axle is fixed at its midpoint to the third member second end and the third member is disposed telescopically within the vertical mast second end so that it is permitted free rotation about the vertical mast.
In one example of the invention described herein, the pivot means comprises the axle mounted in a rotational relationship with a first and second yoke. The first and second yoke are mounted to the mounting member and the pivot means permits rotation of the aerofoil member about the chord line.
In another example of the invention described herein the aerofoil control means comprises a first control line having a first end fixed to the leading edge and a second end anchored to the vertical mast at a point proximate to the first end. The first control line is tensioned to control pitch of the aerofoil member. The control means further comprises aerofoil member tilt control comprising a second control line having a first end fixed to the aerofoil member between the port side of the craft and the vertical mast and a second end fixed to the aerofoil member between the starboard side of the craft and the vertical mast. This creates the second control line port length and starboard length. The second control line travels down-mast to a set of pulleys mounted on the mast and to a two-way winch adapted to tension alternately the port length and the starboard length of the second control line, thereby tilting the aerofoil member port and starboard as desired. The spring tension on the winch is to keep the tilt control line tight to help stabilize the sail and to keep the rope tight enough to provide friction for the rope on the winch drum.
In another example of the invention described herein, the control means further comprises a third control line having a first end fixed to the aerofoil member between the trailing edge and the vertical mast, and a second end fixed to port-starboard traveling means fixed across the stern of the water craft. The traveling means is adapted to move from port to starboard so that the aerofoil member can be rotated about the vertical mast and secured in a desired position.
These and other objects, features, and characteristics of my invention will be more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, wherein like reference numerals designate corresponding parts in the various figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of one example of my invention.

FIG. 2 is a side view of the aerofoil member and mast of another example of my invention.

FIG. 3 is a side view of another example of my invention showing the sail in a tilted configuration.

FIG. 3 a is another embodiment of my invention showing floatation means in the sail.

FIG. 4 is a view of the swivel and pivot means of one example of my invention.

FIG. 5 is a front view of another example of my invention.

FIG. 6 is a top view of one example of my invention.

FIG. 7 is another top view of one embodiment of my invention.

FIG. 8 is a perspective view of another embodiment of my invention.

FIG. 8 a is a perspective view of an embodiment of my invention showing floatation means in the sail.

FIG. 9 is a view of my invention mounted to a catamaran hull.

FIG. 10 is a view of my invention mounted to a large cargo vessel.

DETAILED DESCRIPTION

Referring to FIG. 1 there is shown in side view my invention, a sailing craft 10 comprising a tilting sail system 12. The sailing craft 10 has a hull 14 having a bow 16 and a stern 18, a starboard side 20 and a port side 22. Also illustrated are rudder 23, tiller arm 25 and keel 27. The tilting sail system 12 comprises a sail 24 comprising an aerofoil member 26 capable of an omni-directional attitude for wind propulsion. The aerofoil member 26 is supported by support means 28 for fixing the aerofoil member 26 to the sailing craft 10 and permitting an omni-directional attitude of the aerofoil member. The tilting sail system further comprises aerofoil member control means 30 for placing the aerofoil member 26 in a forward propulsion attitude relative to wind direction. The aerofoil member is rigid and has an asymmetric shape. The aerofoil member is self weather cocking, that is, it will always turn itself into the wind.
Referring to FIGS. 2 and 3, the aerofoil member 26 comprises a leading edge 32, a trailing edge 34, an upper camber 36, a chord 38, a span 40, a centre line 42, a starboard side 44, a port side 46 and a chord line 48. The span 40 is greater than the chord 38. The aerofoil member has a top covering or skin the bottom surface of which is show at circle 37. The aerofoil member also has a bottom skin, which is shown partially as the lines at arrow 33. The bottom skin improves performance of the aerofoil by up to 30% in terms of thrust generated and has been removed in FIG. 3 to show the internal construction of the aerofoil member.
In one embodiment of the invention, the chord 38 at the leading edge 32 (first chord) is the same as the chord (second chord) at the trailing edge 34. In another embodiment of the invention the aerofoil member has a trailing edge (second) chord 39 that is larger than the leading edge (first) chord.
The aerofoil member 26 further includes framing means 50 adapted to maintain an asymmetric shape.
In a conventional sailing system, to stop the craft with soft sail the operator must either turn the craft into the wind or let the sail out with the main sheet to let it luff in the wind. This has the effect of aerodynamically braking the craft. In a high wind situation the soft sail will thrash about severely and needs to be taken down or furled in. With the rigid sail of the present invention the operator can let out the main sheet and let the rigid sail turn with the wind. It will not thrash about because it is rigid. The other option for the operator is just to tilt the rigid sail to a more horizontal position which will lessen the forward drive force and make the rigid sail more vertical. The aerodynamic flow over the sail remains smooth without the sail thrashing. There is no need to furl the rigid sail. To level the craft into a more horizontal plane, the rigid sail can be tilted to a more horizontal attitude which results in less forward drive but more vertical lift on the hull. This has the effect to reducing the heeling of the craft. In a conventional sail system, the operator has to steer the craft more windward or let the main sail off and spill wind. This reduces the forward momentum of the craft. With my invention, the operator has merely to tilt the sail less, that is, bring it to a more horizontal attitude, and the craft heel will lessen without reducing forward momentum of the craft because the air flow will remain constant across the sail surface.
Referring to FIGS. 1, 2 and 3, the aerofoil member 26 support means 28 comprises a vertical mast 52 having a bottom end 54 fixed to the hull 14 and top end 56 for mounting the aerofoil member 26. There are stay members 58 and 59 fixed between the vertical mast 52 and the hull 14 to provide stability to the vertical mast.
The sailing craft 10 further comprises aerofoil member 26 control means 30 for placing the aerofoil member in a forward propulsion attitude relative to wind direction. Control means 30 includes means for controlling the attitude of the aerofoil member for optimizing aerofoil inclination and surface area to wind direction. Means for controlling the attitude of the aerofoil member comprises swivel and pivot means 60 connecting the second end 56 of the vertical mast 52 to the aerofoil member 26 permitting the aerofoil member to adopt a plurality of desired inclination angles.
Referring to FIG. 3 a and FIG. 8 a, floatation material or air bags can be incorporated inside the aerofoil member. FIG. 3 a illustrates floatation blocks (41) which may be made of Styrofoam™ and FIG. 8 a illustrates floatation bags 261 filled with air or some other light gas useful in this application. With floatation means, the aerofoil will never be completely submerged or inverted below the water craft. If the craft is just on its side in a capsize event, the floatation in the aerofoil will permit easy righting of the craft.
Swivel and pivot means 60 comprises a mounting member 64 fixed to the framing means 50 for mounting the swivel and pivot means to the aerofoil member 26.
Referring to FIGS. 1, 2, 3 and 4 swivel and pivot means 60 also include damping means 66 fixed to the swivel and pivot means and disposed within the second end 56 of the vertical mast 52 for damping forces induced into the swivel and pivot means by wind. Swivel and pivot means comprises swivel means for permitting the aerofoil member to swivel 70 around the vertical mast; and, pivot means 72 for permitting rotation 74 of the aerofoil member 26 about the chord line 48.
Damping means 66 comprises a first member 76 disposed within the vertical mast 52 proximate to the second end 56. There is a damping spring 78 disposed within the vertical mast 52. The damping spring has a first end 80 and a second end 82. The first end of the spring 80 rests upon the first member 76. There is also a second member 84 disposed within a third member 86. The second member 84 rests upon the second end 82 of the damping spring 78 and is adapted to transfer forces from the swivel and pivot means to the damping spring. The third member 86 has a first end 88 adapted to receive the second end 82 of the damping spring and a second end 90 fixed to an axle 92. The third member is further adapted for telescopic placement within the second end 56 of the vertical mast 52 thereby permitting reciprocating movement 85 of the third member 86 relative to the vertical mast 52 in reaction to wind forces.
Swivel means comprises axle 92 attached by pivot means 72 to the aerofoil member 26. The axle 92 is fixed at its midpoint 94 to the third member 86 second end 90. The third member 86 is disposed telescopically within the vertical mast second end 56 so that it is permitted free rotation about the vertical mast.
Pivot means comprises the axle 92 mounted in a rotational relationship with a first 96 and second yoke 98. The first and second yokes are mounted to the mounting member 64 through mounting holes 101 using mounting means such as rivets or screws. Pivot means permits rotation of the aerofoil member about the chord line.
Referring to FIG. 3, aerofoil member attitude control means comprises a first control line 100 having a first end 102 fixed to the leading edge 32 of the aerofoil member 26 and a second end 104 anchored to the vertical mast 52 at a point 106 proximate to the first end 54 thereof. The first control line is tensioned to control pitch of the aerofoil member and bias it towards a horizontal orientation.
The control means further comprises aerofoil member tilt control means comprising a second control line 110 having a first end 112 fixed to the aerofoil member 26 between the starboard side 44 and the vertical mast 52 and a second end 114 fixed to the aerofoil member 26 between the port side 46 and the vertical mast 52. This creates a second control line port length and starboard length even though the line is a continuous line with no breaks. The port and starboard lengths travel down the vertical mast 52 to a set of pulleys 120 mounted on the mast and then to a two-way winch 122 adapted to tension alternately the port length and the starboard length of the second continuous control line 110. Tensioning either side of the control line will have the result of tilting the aerofoil member port or starboard as desired. The two-way winch 122 can be either hand operated, foot operated or motor operated. The spring tension on the winch is to keep the tilt control line tight to help stabilize the sail and to keep the rope tight enough to provide friction for the rope on the winch drum.
Control means further comprises a third control line 124 or haul line having a first end 126 fixed to the aerofoil member 26 between the trailing edge 34 and the vertical mast 52 and a second end 128 fixed to port-starboard traveling means (illustrated in FIG. 6) fixed across the stern 18 of the water craft. The traveling means is adapted to move from port to starboard so that the aerofoil member can be rotated about the vertical mast and secured in a desired position.
Referring now to FIG. 5, there is shown a front view of another embodiment of the invention 139. The aerofoil member 140 is shown in a horizontal position such as depicted in FIG. 2. In this position the aerofoil member is in a neutral position or non-propulsive position. However, wind across the surface of the aerofoil will have the effect of lifting the hull 134 of the vessel out of the water due to aerodynamic lift. This would be an optimal position of the sail for motoring as water resistance along the hull would be reduced. FIG. 5 illustrates the top camber 136, the leading edge 138, the chord 143, the starboard side 141 and the port side 142 of the aerofoil member. The span of the aerofoil member can be varied to suit the vessel to which it is attached. Some vessels will have aerofoil members with short spans and others with longer spans. In some cases the span will be less than the chord 143. As illustrated by arrows 146 and 148 the aerofoil member is adapted for tilting to either port or starboard to take advantage of wind direction for optimal propulsion. To tip the aerofoil member to starboard the starboard tilt control line 150 is tensioned by the two-way winch (illustrated in FIG. 1). To tip the aerofoil member to port the port tilt line 152 is tensioned by the two-way winch. The port and starboard tilt control lines are fed to and from the two-way winch by a respective starboard 154 and port 156 pulley blocks fixed opposite each other on the mast 158. The port and starboard tilt control lines are actually a single line have its first 160 and second 162 ends respectively fixed to framing members of the aerofoil member. The tilt control lines remain parallel to the mast and are fixed to the aerofoil member about midway between the mast and the respective port and starboard side of the aerofoil member. FIG. 5 illustrates a first 164 and second 166 rigid stay members fixed between the mast and the hull of the vessel for mast stability. Furthermore, FIG. 5 illustrates a port 168 and starboard 170 forward tension lines fixed between the leading edge of the aerofoil member and the mast to bias the aerofoil member towards a horizontal position.
Referring to FIG. 6, there is shown a top view of an embodiment of the invention 180 illustrating the top surface of the vessel hull 182 and the aerofoil member 184 in a perpendicular relationship to the hull. This position would optimize wind propulsion from a wind blowing from the stern 186 to the bow 188 of the vessel as indicated by arrow 190.
Referring to FIG. 4 and FIG. 6, arrow 192 indicates that the aerofoil member is able to pivot around mast 194 using the swivel and pivot means 195 to take advantage of wind direction. In FIG. 6, the aerofoil member is tilted full to the starboard side of the vessel by pivot means and then swiveled so that it is perpendicular to the hull of the vessel. Also illustrated in FIG. 6 are the port 196 and starboard 198 tilt control lines, which in this embodiment, travel down the mast 194 and down the centre-line of the hull to the two-way winch 202. In this embodiment the two-way is activated using a foot spinner 204 so that the operator can use both hands and feet to control the vessel. The tiller bar 206 is shown in close proximity to the two-way winch. The traveler 208 which is placed on a traveler-rod 210 across the stern 186 of the vessel is attached to the haul line 214 first end 216 and used to pull the aerofoil member trailing edge 218 towards the stern during tacking operations. The haul line second end 218 is fixed to the aerofoil member about midway between the trailing edge 220 and the mast. The port 222 and starboard 224 stays are shown fixed between the mast and the hull for mast stability.
FIG. 7 illustrates one embodiment of the invention showing one advantage of the invention. The aerofoil member 230 is tilted full to starboard and swiveled to the position illustrated using the haul line 232. Note that the traveler 234 has moved along the traveler rod 236 to a centre position. The wind direction 239 is almost bow-on being about 10 degrees to port and co-linear with the chord line 241. The aerofoil member is able to propel the vessel through the aerodynamics of lift since movement over the camber 240 of the aerofoil member will create a lift force vector 242 that can be resolved to a propulsion force 244.
FIG. 8 illustrates another embodiment of the invention 250 in a plan-perspective view. The aerofoil member 252 is mounted by mast 254 to the hull 256 of the vessel 258. The aerofoil member has a top camber 260 and maintains its shape by way of rigid framing members 262. The aerofoil member has a chord 263, a span 265, a leading edge 264, a trailing edge 266, a starboard side 268 and a port side 270. A first control line 272 first end 274 is attached mid-way along the leading edge 264 of the aerofoil member and the first control line second end 276 is attached to the mast 254. The first control line is elastic and tensioned to bias the aerofoil member to the horizontal position. Swivel and pivot means 280 of the embodiment illustrated in FIG. 4 are attached to mounting member 282 between two framing members 262. The swivel and pivot means 280 is attached in a swiveling relationship to the top end 284 of the mast. A port tilt control line 286 and a starboard tilt control line 288 have their respective first ends 290 and 292 attached to the aerofoil member framing members 262 mid-way between the mast and the port and starboard sides of the aerofoil member. The port and starboard tilt control lines are in fact a single line and engage a two-way winch 294 located in the stern of the vessel for operator tilt control. The port and starboard tilt control lines communicate with the two-way winch through port and starboard pulleys 296 and 298 respectively. The two-way winch is operable by hand or by foot using control wheel 300. The tiller bar 302 is attached to the rudder 304 and is in close proximity to the control wheel 300 so that a single operator can control and maneuver the vessel. The haul line 306 has a first end attached to traveler 310 and second end 312 attached in the rearward-middle 314 of the aerofoil member. The traveler is adapted to move port-starboard along a traveler rod 316. Port stay 318 and starboard stay 320 are illustrated fixed between the mast and the hull for mast stability.
FIG. 9 illustrates another embodiment of the sailing system 340 comprising a catamaran hull 342 comprising a port 344 and starboard 346 hull members fixed together by framing means 348. Framing means is covered by a sheet 350 to support the operator. The aerofoil member 352 is partially illustrated to show the associated controls. The swivel and pivot means 354 is illustrated mounted between a first 356 and second 358 inboard framing members. There would be two or more additional framing members (not illustrated) depending on the size of the aerofoil member. The swivel and pivot means comprises a first 360 and second 362 mounting members to which are mounted a first 364 and second 366 cambered members. Bridging the first and second cambered members is a member 368 comprising a ball and socket joint where the ball portion is mounted to the top end of the mast and the socket is integral to the bridge member 368. This arrangement permits port and starboard tilting of the aerofoil member for maximum maneuverability and only allows a limited amount of tilting bow-ward and stern-ward to avoid inducing aerodynamic wind forces that might lift the vessel out of the water. The port tilt control line 380 and the starboard tilt control line 382 is a single line fixed at a first end 384 to a framing member between the mast and starboard side of the aerofoil member and a fixed at a second end 386 to a framing member between the mast and the port side of the aerofoil member. The tilt control lines are bound at 388 to a tilt control rod 390 which has a first end fixed in a pivoting relationship with catamaran framing member 392 and a second free end that is engaged with a serrated catamaran framing member 396. The control rod 390 is illustrated engaged with a central serration 398 on member 396 to maintain the aerofoil member horizontal. To induce a port-side tilt to the aerofoil member the operator disengages the rod 390 from the middle serration and moves the rod to starboard to engage another of the serrations. A similar operation is used to induce a starboard tilt by moving the control rod to the port and engaging another serration. The tilt control line communicates with the control rod through a first set of pulleys 400 and 402 mounted at the base of the mast and a second set of pulleys 404 and 406 mounted at each of the stern corners 408 and 410 of the catamaran frame. A forward tensioning control line 412 is mounted between the centre leading edge 414 of the aerofoil member and the mast to bias the aerofoil to the horizontal position. The haul line 416 is illustrated as engaging pulley 418 fixed to the trailing edge 420 of the aerofoil member and having a first end fixed to traveler 422 on traveler rod 424 for port-starboard motion. The second end 426 of the haul line is free for control by the operator so that pulling on the second end will pull the aerofoil trailing edge toward the centerline of the vessel. A port 428 and starboard 430 stays are illustrated fixed between the mast and the catamaran frame. The tiller arm 432 is illustrated in mechanical communication with the port 434 and starboard 436 rudders.
FIG. 10 illustrates another embodiment of the invention 450 wherein the vessel 452 is a large cargo vessel displacing thousands of tons. The sail system 454 can be a double aerofoil 456 and 458 as illustrated or the sail system can be a plurality of aerofoils. The sail system on the larger vessels is the same as on the smaller vessels. Each aerofoil is supported by a mast 460 and 462 and each mast is stabilized by at least one stay 464 and 466. The control lines some of which are visible in this figure would be configured substantially the same as in the smaller vessels with port and starboard tilt control lines (468 to 474) and haul lines (476 and 478) linked to a winch mechanism (not shown) so that the aerofoils could be controlled in unison. Computer means (not shown) including wind sensing means can be installed to control the sails in order to optimize wind propulsion and save fuel.
This description contains much specificity that should not be construed as limiting the scope of the invention but merely provides illustrations of some of its embodiments. Thus the scope of the invention should be determined by the appended claims and their legal equivalents rather than by the examples given.

Claims

1. A sailing craft comprising a tilting sail system, said sailing craft having a hull having a bow and a stern, a port side and a starboard side, said sail tilting sail system comprising:

a. a sail comprising an aerofoil member capable of omni-directional attitude for wind propulsion;

b. aerofoil member support means for fixing said aerofoil member to the sailing craft and permitting omni-directional attitude; and,

c. Aerofoil member control means for placing the aerofoil member in a forward propulsion attitude relative to wind direction.

2. The sailing craft of claim 1, wherein said aerofoil member is rigid and has an asymmetric shape.

3. The sailing craft of claim 2, wherein the aerofoil member is self weather cocking.

4. The sailing craft of claim 3, wherein the aerofoil member comprises a leading edge, a trailing edge, an upper camber, a chord, a span, a centre line, a port side, a starboard side and a chord line.

5. The sailing craft of claim 4, wherein said span is greater than said chord.

6. The sailing craft of claim 4 wherein the aerofoil member has a first chord at said leading edge and a second chord at said trailing edge, and wherein said second chord is larger than said first chord.

7. The sailing craft of claim 3 wherein the aerofoil member further includes framing means adapted to maintain said asymmetric shape.

8. The sailing craft of claim 1, wherein said aerofoil member support means comprises a vertical mast having a bottom end fixed to said hull and top end for mounting the aerofoil member.

9. The sailing craft of claim 8 wherein the aerofoil support means further comprises at least one stay member fixed between said vertical mast and the hull to provide stability to the vertical mast.

10. The sailing craft of claim 1, wherein aerofoil member control means for placing the aerofoil member in a forward propulsion attitude relative to wind direction comprises means for controlling the attitude of the aerofoil member for optimizing aerofoil inclination and surface area to wind direction.

11. The sailing craft of claim 10, wherein means for controlling the attitude of the aerofoil member comprises;

a. Swivel and pivot means connecting said second end of the vertical mast to the aerofoil member permitting the aerofoil member to adopt a plurality of desired inclination angles; and,

b. Control means for placing and maintaining the aerofoil member to adopt one of said plurality of desired inclination angles.

12. The sailing craft of claim 11, wherein said swivel and pivot means comprises:

a. A mounting member fixed to said framing means for mounting the swivel and pivot mean to the aerofoil member;

b. Damping means fixed to the swivel and pivot means and disposed within the second end of the vertical mast for damping forces induced into the swivel and pivot means by wind;

c. Swivel means for permitting the aerofoil member to swivel around the vertical mast; and,

d. Pivot means for permitting rotation of the aerofoil member about said chord line.

13. The sailing craft of claim 12, wherein said damping means comprises:

a. a first member disposed within the vertical mast proximate to the second end;

b. a damping spring disposed within the vertical mast, said damping spring member having a first end and a second end, wherein said first end rests upon said base member;

c. a second member disposed within a third member, wherein said second member rests upon said second end of the damping spring member and is adapted to transfer said forces from the swivel and pivot means to the damping spring; and,

d. said third member having a first end adapted to receive the second end of the damping spring and a second end fixed to an axle, wherein the third member is further adapted for telescopic placement within the second end of the vertical mast thereby permitting reciprocating movement of the third member relative to the vertical mast in reaction to the forces.

14. The sailing craft of claim 13, wherein said swivel means comprises said axle attached by said pivot means to the aerofoil member, wherein the axle is fixed at its midpoint to the third member second end, and further wherein the third member is disposed telescopically within the vertical mast second end so that it is permitted free rotation about the vertical mast.

15. The sailing craft of claim 14, wherein the pivot means comprises the axle mounted in a rotational relationship with a first and second yoke, said first and second yoke mounted to the mounting member; the pivot means permitting rotation of the aerofoil member about the chord line.

16. The sailing craft of claim 15, wherein the control means comprises a first control line having a first end fixed to said leading edge and a second end anchored to the vertical mast at a point proximate to the first end thereof, wherein said first control line is tensioned to control pitch of the aerofoil member.

17. The sailing craft of claim 16, wherein the control means further comprises aerofoil member tilt control comprising a second control line having a first end fixed to the aerofoil member between said port side and the vertical mast and a second end fixed to the aerofoil member between said starboard side and the vertical mast, thereby creating said second control line port length and starboard length, and wherein the second control line travels down-mast to a set of pulleys mounted on the mast and to a two-way winch adapted to tension alternately said port length and said starboard length of the second control line, thereby tilting the aerofoil member port and starboard as desired.

18. The sailing craft as claimed in claim 17, wherein the control means further comprises a third control line having a first end fixed to the aerofoil member between said trailing edge and the vertical mast, and a second end fixed to port-starboard traveling means fixed across the stern of the water craft, said traveling means adapted to move from port to starboard so that the aerofoil member can be rotated about the vertical mast and secured in a desired position.

19. A sailing craft comprising a tilting sail system, said sailing craft having a hull having a bow and a stern, a port side and a starboard side, said sail tilting sail system comprising:

a. a self weather cocking sail comprising a rigid and asymmetric aerofoil member capable of omni-directional attitude for wind propulsion;

b. aerofoil member support means for fixing said aerofoil member to the sailing craft and permitting omni-directional attitude;

c. aerofoil member control means for placing the aerofoil member in a forward propulsion attitude relative to wind direction, wherein aerofoil member control means comprises means for controlling the attitude of the aerofoil member for optimizing aerofoil inclination and surface area to wind direction; and, wherein means for controlling the attitude,

d. the aerofoil member comprises a leading edge, a trailing edge, an upper camber, a chord, a span, a centre line, a port side, a starboard side and a chord line, and wherein said span is greater than said chord.

20. The sailing craft of claim 19, wherein said aerofoil member support means comprises:

a. a vertical mast having a bottom end fixed to said hull and a top end for mounting the aerofoil member, at least one stay member fixed between said vertical mast and the hull to provide stability to the vertical mast, and swivel and pivot means connecting said second end of the vertical mast to the aerofoil member permitting the aerofoil member to adopt a plurality of desired inclination angles;

b. Control means for placing and maintaining the aerofoil member to adopt one of said plurality of desired inclination angles; and wherein,

c. said swivel and pivot means comprises:

i. A mounting member fixed to said framing means for mounting the swivel and pivot mean to the aerofoil member;

ii. Damping means fixed to the swivel and pivot means and disposed within the second end of the vertical mast for damping forces induced into the swivel and pivot means by wind;

iii. Swivel means for permitting the aerofoil member to swivel around the vertical mast; and,

iv. Pivot means for permitting rotation of the aerofoil member about said chord line.