AU4857297A

AU4857297A - A pivoting sailing rig

Info

Publication number: AU4857297A
Application number: AU48572/97A
Authority: AU
Inventors: Robert Dane
Original assignee: Solar Sailor Pty Ltd
Current assignee: Solar Sailor Pty Ltd
Priority date: 1996-11-11
Filing date: 1997-11-11
Publication date: 1998-06-03
Anticipated expiration: 2017-11-11
Also published as: AU717925B2

Description

"A PIVOTING SAILING RIG"

TECHNICAL FIELD

This invention relates to a pivoting sailing rig, and particularly to a method of mounting a sail relative to a vehicle so that the sail can be reefed by adjusting the orientation of the sail relative to the vehicle. In a preferred embodiment, the sail includes solar collectors such that said adjustment also controls the collection of energy from the sun.

This invention has particular but not exclusive application to wing sails and especially to multi-hull waterborne craft utilising multiple wing sails.

BACKGROUND ART

GB patent 2 234 723 to Crafer discloses a wing sail including photovoltaic cells in which the wing sail can be stored. More particularly, the patent discloses a multi-hull waterborne craft including an assembly of three wing sails, each wing sail being rotatable in concert about its longitudinal axis and the assembly of wing sails itself rotatable about a vertical axis coincident with the longitudinal axis of the middle wing sail. For stowage, the assembly of wing sails can be rotated to a line abeam configuration at which the assembly can then be stowed by pivoting the assembly about a horizontal abeam axis to lie the assembly down on the deck of the craft.

DISCLOSURE OF INVENTION

The present invention in one aspect relates to a method of pivotably mounting a sail to a vehicle, the method including mounting the sail to the vehicle on a pivot axis which is parallel to the longitudinal axis of the vehicle such that the sail is pivotable in a plane which is transverse to the longitudinal axis of the vehicle to thereby reef the sail, and such that the sail is restricted to movement in said transverse plane.

In a highly preferred embodiment, the sail is a wing sail and the wing sail includes a solar collector. In one form, the vehicle includes a pair of wing sails, the wing sails being transversely spaced across the vehicle.

In another aspect the invention resides in a vehicle including a sail, the sail being mounted at its base to the vehicle for pivotal movement about an axis which is parallel to the longitudinal axis of the vehicle, reefing means being provided for pivoting the sail between an upright position and a reefed position.

BRIEF DESCRIPTION OF DRAWINGS

In order that this invention may be more easily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention, wherein: -

FIG 1 is a side perspective view of a craft incorporating a pair of wing sails;

FIG 2 is an end view of the craft of FIG 1 with both wing sails in a generally upright configuration; FIG 3 is an end view of the craft of FIG 1 with one of the wing sails in an upright configuration and one in a reefed position.

FIG 4 is a detailed view of one possible coupling arrangement which can be used to mount the wing sail to the craft;

FIG 5 is an alternative coupling arrangement.

BEST MODE

FIGS 1, 2 and 3 illustrate a craft 10 incorporating a pair of wing sails 12. These sails are laterally spaced across the craft and are disposed adjacent the opposite sides of the craft with the surface carrying the solar panel located on the inwardly facing surfaces of the sails. Alternatively, both sides of the sail bear solar collectors or, alternatively again, the sail is transparent and double-sided solar collectors are located within the sail .

The wing sails extend from the craft in a wing or arm- like manner and, together with the deck, they present three solar collecting surfaces which together define a flat or concave solar collector. A coupling arrangement is provided to mount the proximal end of each sail 12 to the craft 10 so as to provide movement of the sails relative to the craft.

With reference to FIG 4, the craft 10 incorporates a frame structure on its deck. The frame structure includes a series of laterally extending members 14. These laterally extending members 14 incorporate riggers 16 at their outer ends. These riggers 16 incorporate a central passage which extends in the direction of the centre line of the craft and are disposed adjacent to the outer sides of the craft.

As best illustrated in FIG 4, these riggers are adapted to mount a primary shaft 18 of the coupling arrangement. The primary shaft 18 is rotatable within the riggers so as to be rotatable about an axis which is substantially parallel with the centre line of the craft. Moreover, the primary shaft is adapted for limited axial movement in the riggers .

A male coupling element 20 extends radially outwardly from the shaft and is adapted to be located within a bore in the wing sail (or mast of a sail) to thereby mount the wing sail or sailing rig onto the primary shaft. In this arrangement, the longitudinal axis of the sail is disposed substantially perpendicular to the axis of the primary shaft. In the illustrated form, the male coupling element 20 incorporates a height adjustment member 22 adapted to adjust the spacing between the wing sail 12 and the primary shaft 18. Furthermore a stay 24 is provided to secure the wing sail in position on the male coupling element. A benefit of using the stay is that, as it is under tension, it enables a distribution of the loading along the wing sail . With the arrangement, rotation of the primary shaft 18 causes the wing sail 12 to move from a generally upright configuration as illustrated in FIG 2 to a lateral or reefed position as illustrated in FIG 3. Furthermore, axial movement of the primary shaft 18 enables the position of the mounting of the wings to be varied in the fore-aft direction. In some embodiments the primary shaft may also be moved inboard or outboard of the craft .

The coupling arrangement is also adapted to allow rotation of the sailing rig or wing 12 about its longitudinal axis. This rotation is provided by rotation of the wing 12 about the male element 20. To facilitate this movement, bushes 26 are disposed along the male coupling element. With this arrangement, the angle of attack of the wing may be varied whilst the wing is in a generally upright configuration relative to the craft or in a reefed or partially reefed configuration where it extends laterally to the craft. This rotation enables variation in the lift characteristics of the wing, enables the heading of the craft relative to the wind to be varied for effective sailing at various angles to the wind direction, and optimum orientation to the sun for solar collection.

The coupling includes a control arrangement to control the pivoting or reefing of the wing sail. In the illustrated form, this control arrangement includes a control arm 28 which extends radially outwardly from the primary shaft 18 in angular spaced relationship to the male coupling element 20. In the illustrated form, the angle formed between the control arm 28 and the male coupling element 20 is in the vicinity of 90°.

To control the inclination of the sail, rigging 30 (FIG 3) is provided between the control arm 28 and the deck of the craft. The rigging incorporates ropes, pulleys and cleats and is arranged to locate the control lever in preselected positions relative to the deck of the catamaran (of course this control may be provided by hydraulics or other means) . This in turn dictates the angular position (reefing) of the wing sail. A pulley system (not shown) is preferably used with the ropes to provide a mechanical advantage to assist in positioning of the sails. To control rotation of the wing sail about its longitudinal axis, rigging 32, 34 (FIG 4) is provided between the respective leading and trailing edge of the wing sail and the control lever 28. Through adjusting the rigging, the angle of attack of the wing sail can be controlled. Furthermore the wing sail can be luffed or feathered. Again, this control may be achieved by hydraulics, electric motors or other means.

As best illustrated in FIG 2 and 3, the control arms 28 extend inwardly onto the deck of the catamaran. With this arrangement, the catamaran can be operated by one or two persons as each of the control arms can be accessed from the centre of the craft thereby enabling the positions of the two wing sails 10 to be controlled. Moreover in this position, the craft rudder and motor can also be easily accessed.

In a preferred embodiment the wing sail adopts a default semi-reefed orientation of 45 degrees by use of springs or other resilient means. This means that the sail must be urged to the extreme upright and horizontal (fully reefed) positions shown in FIGS 2 and 3, respectively. This is advantageous because, if the default position is the horizontal position shown in FIG 3, it is difficult to raise the sail due to a lack of mechanical advantage when the sail is horizontal. A modified coupling arrangment in shown in FIG 5. As will be noted, the control arm 28 has been extended in the outboard direction. Thus, this outboard extension of the control arm can be used to urge the sail towards the fully reefed position.

The craft exhibits high performance characteristics for solar powered motor sailing. The wings mounted on the craft with their aerodynamic shape and multi- directional movement capabilities are very versatile allowing a plurality of additional functions as compared to traditional rigging. These include being able to impart lift or stability forces to the craft, being able to change the characteristics of the craft such as its centre of gravity and windage, and being able to be precisely adjust the solar collectors on the sails to face the sun. Mounting the solar panels on the wing enables a large surface of solar collecting to be incorporated on the craft without unduly affecting the performance of the craft. Moreover, because of the angular adjustment possible with the wing, the solar panels are able to provide maximum exposure to the surface of the assembly for solar collecting. By mounting the wings as shown, shading of the deck is avoided and the deck space can be advantageously used for solar collection.

The advantages provided by the wing assembly of the invention in solar powered motor sailing is further enhanced by incorporating a plurality of wing sails in the craft as it enables various combinations of functions to be carried out by the assemblies which are not possible by a single wing assembly. For example, one wing can be adapted to be accurately tracking the sun or providing additional stability to the craft whilst the other wing is in an upright configuration to provide forward drive to the craft. Moreover, the wing assemblies can work together to better optimise the force imparted to the craft .

The energy which can be harvested from the wind by a sail is proportional to the cube of the relative wind velocity. It follows that the use of solar energy to drive the craft increases the relative wind velocity

(except when running downwind) thereby improving sailing efficiency.

It will be understood that any form of pivotal mounting can be used to mount the sail to the craft including resilient material, hinge mechanisms etc. It will be understood that alternative control means such as hydraulic, electric motors etc. may replace the cable rigging.

A major drawback with wing sails has previously been the inability to reef a wing sail. Traditionally, it has only been possible to feather or luff the sail. The present invention allows the partial or complete reefing of a wing sail and the mounting arrangement which achieves this result can also be advantageously used to allow the wing sails to track the sun for solar collection.

Finally, it will be understood that various alterations, modifications and/or additions may be introduced into the construction and arrangement of the parts previously described without departing from the spirit or ambit of the invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS : -

1. A method of pivotably mounting a sail to a vehicle, the method including mounting the sail to the vehicle on a pivot axis which is parallel to the longitudinal axis of the vehicle such that the sail is pivotable in a plane which is transverse to the longitudinal axis of the vehicle to thereby reef the sail, and such that the sail is restricted to movement in said transverse plane.

2. A method as defined in claim 1, wherein the sail is a wing sail .

3. A method as defined in claim 1, wherein the sail includes a solar collector.

4. A method as defined in claim 1, wherein the vehicle includes a pair of wing sails, the wing sails being transversely spaced across the vehicle.

5. A vehicle including a sail, the sail being mounted at its base to the vehicle for pivotal movement about an axis which is parallel to the longitudinal axis of the vehicle, reefing means being provided for pivoting the sail between an upright position and a reefed position.

6. A vehicle as defined in claim 5, wherein there are a pair of transversely spaced sails.

7. A vehicle as defined in claim 5, wherein feathering means are disposed between the reefing means and sail.