AU717925B2 - A pivoting sailing rig - Google Patents

Description

;~"riii~~ Pcr/AU 97/007 6 6 RECEIVED 1 0 SEP 1998 1 "A PIVOTING SAILING RIG" TECHNICAL FIELD This invention relates to a pivoting sailing rig, and more particularly to a pivoting sailing rig which facilitates the collection of energy from both wind and sun.

BACKGROUND ART With a growing awareness of the need to utilise renewable energy sources, there has been an increased focus on wind and solar energy.

It is known from GB patent 2,234,723 to mount solar collectors on a wing sail. This document discloses an assembly of three wing sails, each wing sail being rotatable in concert about its longitudinal axis and the assembly of wing sails being 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 and then pivoted about an abeam axis to lie the assembly down on the deck.

DISCLOSURE OF INVENTION According to one aspect the invention resides in a vehicle including a wing sail pivotable at its base about a reefing axis parallel to the fore-aft axis of the vehicle whereby the wing sail can be reefed between a substantially upright position and a substantially horizontal position, the vehicle including reefing means for controlling the reefing of the wing sail relative to the vehicle about the fore-aft axis, the wing sail defining a longitudinal axis and being rotatable about its longitudinal axis whereby the wing sail can be \R A/feathered, the vehicle including feathering means for S ontrolling rotation of the wing sail about its /NT AM~fl' SHEET 0iAU cr/Au 9 7 0 0 7 6 6 RECEIVED 1 0 SEP 1998 2 longitudinal axis, wherein the wing sail includes solar collecting means and wherein the reefing and feathering of the wing sail can be used to optimise energy collection from sun and wind.

In a highly preferred embodiment there are a pair of transversely spaced wing sails.

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 horizontal or reefed position.

FIG 4 is a detailed view of one possible coupling, reefing and feathering arrangement; FIG 5 is an alternative coupling, reefing and feathering 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. In one embodiment, the surface carrying the solar panel is located on only the inwardly facing surfaces of the sails. Alternatively, both sides of the sail bear solar collectors or, alternatively again, in a preferred arrangement the sail K-i can be transparent and double-sided (bi-facial) solar ')collectors can be safely located within the sail.

The wing sails extend from the craft in a wing or AMNE D SHEET iPFAi/AU PCTf7 O 7 76 0 ~E~~DI 0 SEP I598 3 arm-like manner and, together with the deck, they present three solar collecting surfaces which together define a flat or concave composite solar collector when viewed in the fore-aft direction as shown in FIGS 2 and 3.

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 hollow cylindrical riggers 16 at their outer ends. These riggers 16 define a central passage which extends parallel to the centre line of the craft.

As best illustrated in FIG 4, the 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.

The primary shaft is also mounted for limited axial movement (fore-aft) within 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 to thereby mount the wing sail 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 incorporates a height adjustment member 22 adapted to adjust the spacing between the wing sail 12 and the primary shaft 18. A stay 24 is provided to secure the wing sail in position on the male coupling element.

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 i primary shaft 18 enables the position of the mounting of ,the wings to be varied in the fore-aft direction. In M

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Pcr/Au9 7 0 0 7 6 RECEIVED l 0 SEP 1998 4 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 (ie. "feathering"). This rotation is provided by rotation of the wing 12 on the male element 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 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 900.

To control the inclination of the sail, rigging (FIG 3) is provided between the control arm 28 and the deck of the craft. The rigging incorporates ropes, pulleys and cleats in the usual manner (of course this control may be provided by hydraulics or other means, particularly in larger vessels). In smaller vessels, 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 L longitudinal axis, rigging 32, 34 (FIG 4) is provided -Ibetween the respective leading and trailing edge of the L)Iwing sail and the control lever 28. Through adjusting AMENDED

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CrTAu 9 7 O 7 6 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 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 from the inclined default orientation 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 multidirectional 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 A D .8HErT

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Pcr/Au 9 7 0 0 7 6 6 RECEIVED 1 0 SEP 1998 6 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. This is a "positive feedback loop" in which the energy collected from the sun is advantageously used to enhance the collection of energy from the wind through improved efficiencies.

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 Z'the inability to reef a wing sail. Traditionally, it has AMEINDD 8HEET P CTru 9 7/ 076 6 RECEIVED 1 0 SI 7 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 (6)

1. A vehicle including a wing sail pivotable at its base about a reefing axis parallel to the fore-aft axis of the vehicle whereby the wing sail can be reefed between a substantially upright position and a substantially horizontal position, the vehicle including reefing means for controlling the reefing of the wing sail relative to the vehicle about the fore-aft axis, the wing sail defining a longitudinal axis and being rotatable about its longitudinal axis whereby the wing sail can be feathered, the vehicle including feathering means for controlling rotation of the wing sail about its longitudinal axis, wherein the wing sail includes solar collecting means and wherein the reefing and feathering of the wing sail can be used to optimise energy collection from sun and wind.

2. A vehicle as claimed in claim 1, wherein there are a pair of transversely spaced wing sails.

3. A vehicle as claimed in claim 1, wherein the wing sail adopts a default semi-reefed position intermediate the substantially upright position and the substantially horizontal position.

4. A vehicle as claimed in claim 1, wherein the wing sail includes a socket or bore for receiving a mounting spigot whereby the wing sail is mounted relative to the vehicle.

A vehicle as claimed in claim 1, wherein the wing sail is transparent adjacent the solar collecting means and wherein the solar collecting means includes bi-facial S solar collectors.

6. A vehicle as claimed in claim 5, wherein the bi- LU AM. I /AU 9 7 0076 6 RECEVED 1 0 S01 9 facial solar collection means are mounted inside a transparent skin which defines the exterior of the wing sail. 'ii- i'~ir~cC,