WO1984004362A1

WO1984004362A1 - Wind driven power source

Info

Publication number: WO1984004362A1
Application number: PCT/GB1984/000146
Authority: WO
Inventors: Gyula Vari
Original assignee: Gyula Vari
Priority date: 1983-04-27
Filing date: 1984-04-27
Publication date: 1984-11-08
Also published as: GB8311463D0; EP0150188A1

Abstract

The power source has a shaft (2) driven to rotate by arms (11) carrying vanes (12). Each vane has two parts (24, 25) which are hinged together for opening and closing movement along a vertical axis (Fig. 2) when the arms (11) are rotated by the wind. The arms (11) are telescopically extensible and their effective lengths are controlled by a wind-speed sensor such as centrifugal weights (18) rotatable with the shaft (2). In another embodiment, the vanes parts are part circular cylindrical in shape (see Fig. 5). The vanes may also consist of hemispherical bowls of pairs of hemispherical bowls (see Fig. 6) rotatable relative to each other to provide a closed spherical configuration or an open hemispherical configuration. The power source can be used on a ship or boat (Figs. 7 and 8) to drive the vessel's propellers directly, or to generate electrical power which is stored for subsequent use to drive an electric motor to propel the vessel.

Description

WIND-DRIVEN POWER SOURCE

Description

This invention relates to wind-driven power sources and also to marine propulsion systems.

The aim of the invention is to provide a power source capable of converting wind energy efficiently into rotational motion of an output ^"shaft of the power source. The rotatable output shaf may be coupled to electrical generator means for generation of electricity by wind power. Power sources according to the invention can be suitable for marine use. The present invention provides a wind-driven power source having an output shaft driven by rotatable arm means carrying and/or constituting wind-engaged surfaces, the source including means for modifying the shape and/or aspect of the wind-engaged surfaces in response to changes in wind speed.

Conveniently, the arm means comprise one or more extensible and contractible arms, the source including wind speed sensing means operatively connected to control means arranged to change the effective length of the arm(s) in response to changes in wind speed.

The invention also provides a wind-driven power source having an output shaft driven by rotatable arm means carrying and/or constituting wind-engaged surfaces, the arm means comprising one or more arms which are extensible and contractible for change of their effective lengths.

This latter wind-driven power source may include control means for changing the effective length of the arm(s) . These means may be responsive to wind-speed sensing means or, alternatively, may be operable by an operator of the power source, for example a helmsman at the helm of a ship or boat powered by a wind-driven power source according to the invention. The wind-speed sensing means of a power source according to the invention may be indirect and respond to the rotational speed of the output shaft, or may be responsive directly to wind speed. The effective length of the arm means is preferably reduced in response to increasing wind speed and increased when the wind speed decreases.

A power source according to the invention conveniently comprises a plurality of vane-support arms (for example three, four, six or eight arms) ^'extending outwardly from a substantially vertical shaft which they drive to rotate. The arms are preferably inclined up¬ wardly at either a selectively variable angle or a fixed angle, preferably of about 37i° to the horizontal. Each vane-support arm will usually carry a vane and this may comprise a first vane member attached to the^* arm means and a second vane member pivotally mounted on the first member, the vane members being pivotable re¬ lative to each other between a closed position in which the vane members lie adjacent each other and an open position in which the members are spaced apart at their edges which trail during rotation of the arm means.

Preferably, the first and second vane members are relatively pivotable about a substantially vertical axis. In some power sources according to the invention, the first and second vane members are substantially planar. However, other vane member shapes are possible and the vane members may be each part cylindrical and arranged with their axes mutually parallel and their concave faces directed towards each other.

Preferably, the power source includes resilient biassing means urging the first and second vane members into their closed position.

Another form of vane which may be used with a power source according to the invention is one comprising a hollow member having internal wind-engaged surfaces. One such vane comprises first and second hollow hemispherical members which are relatively rotatable, preferably in response to extension of the arms means, about a common diameter from a first condition in which they provide a substantially continuous spherical sur- face and a second condition in which one member is receive in the other member to provide a hemispheriscal internal wind-engaged surface.

In another aspect, the present invention provides a marine vessel having one or more wind-driven power sources each having a rotational output shaft, the vessel including transmission means operable to couple the or each output shaft to a propulsion means of the vessel.

The power source(s) are advantageously, but need not be, in accordance with the above paragraphs.

Advantageously, the vessel includes electrical generator means, means for storage of electrical power generated by the generator means, and electric motor means capable of being powered by the storage means, the transmission means being operable in a first condition in which the or each output shaft is coupled to the pro¬ pulsion means to power the vessel, in a second condition in which the or each output shaft is coupled to the elec¬ trical generator means and generated electrical power can be stored in the storage means, and in a third condition in which the electric motor means are powered by the storage means and are coupled to the propulsion means.

Such a vessel can be powered by the wind-driven power source when the transmission is in its first condition or, when sufficient wind power is not available, the transmission in its third condition allows the vessel to be powered electrically. In the second transmission condition, electricity may be generated and stored at times when wind power is available but propulsion of the vessel is not required. Preferably, the transmission means is operable in its first and its second conditions simultaneously. Thus, when sufficient wind power is available, the vessel can be propelled by wind power and energy generated stored for future use.

The propulsion means will usually comprise pro¬ pellers, preferably of variable pitch, but may otherwise comprise hydrojets.

The generator means and electrical motor means are of the DC type in which electromagnetic field coils are excited by an excitation current. However, permanent magnet motor and generator means may also be used in marine vessels according to the invention.

Embodiments of the invention will now be described by way of example with reference to the drawings, in which:

Figure 1 is a part sectional schematic view of a first wind-driven power source embodying the invention;

Figure 2 is a fragmentary plan view of the power source of Figure 1 ; -

Figures 3 and 4 are part sectional schematic side views of parts of a second wind-driven power source embodying the invention;

Figure 5 is a schematic plan view of the power source of Figures 3 and 4;

Figure 6 is a schematic plan view of part of a third wind-driven power source embodying the invention;

Figure 7 is a sectional schematic side view of a first ship or boat having a propulsion system embodying the invention; and

Figure 8 is a schematic plan view of a second ship or boat having apropulsion system embodying the invention.

The wind-driven power source 10 shown in Figure 1 comprises a rotatable output shaft 2 journalled in upper and lower bearings 4,5 so as to extend generally vertically through a deck 6 or other mounting surface. The upper bearing 4 is supported by stays 8 or guide ropes.

Above the upper bearing 4, the output shaft 2 carries telescopically extensible arms 11. Two of these arms 11 are shown in Figure 1 , but there may be a single arm suitably counterbalanced, or more than two such arms, for example four arms as shown in Figure 2. The power source 10 is intended for use on ship- board although its use is not so limited and to provide clearance beneath the arms 11 , these may be inclined upwardly as shown, for example at an angle of about 35° to 40°, preferably 37£°, to the horizontal, or at an angle which can be selectively adjusted. The arms 11 carry vane structures 12 at their free upper ends and impingement of the wind on these vane struc¬ tures, and also on the arms themselves, will cause rota¬ tion of the output shaft 2, from which a drive can be supplied to driven means located below the deck. Each arm 11 has an inner arm portion 14 extending from the output shaft 2, which is tubular, and an outer arm portion 15, to which the vane structure 12 is secured, which is telescopically slidable within the inner arm portion 14. The two arm portions 14,15 are either of non-circular cross-section, for example of oval cross-section, or, if circular, are provided with a splined or other connection so that relative rotation about their longitudinal axes is prevented. The arm portions 14 can be braced by a frame or other means (not shown) connecting their outer ends. The arm portions are biassed by a tension spring 16 to the telescopically extended position shown and the portion 15 can be retracted within the portion 14 when desired to reduce the drive torque applied to the shaft 2. The operative length of the arm 11 can be controlled as shown by a regulating mechanism carried on a portion of the output shaft 2 upwardly beyond

OMPI the join with the arm portions 14. The regulating mechanism comprises weights 18 carried on a linkage 20 permitting outward movement of the weights under centrifugal force in response to rotation of the shaft 2. A cable 21 extends from the linkage 20 by way of a pulley 22 to the arm portion 15, so that this is pulled into the arm portion 14 against the force of the spring 16 as the rotational speed of the output shaft 2 increases. The radial spacing of the vane structures 12 from the axis of the output shaft 2 is consequently reduced so as to reduce the rotational speed of the output shaft for a given wind speed. It will be understood that the arms 11 can comprise more than two telescopically associated portions if desired and may be shaped to provide wind—impingement areas to assist or replace those of the vane structures 12. Also, arm extension and retraction can be effected hydraulically if preferred, either automatically in response to wind speed or by an operator of the power source.

In the embodiment described above, control of the rotation speed of the output shaft 2 is effected automatically in response to wind speed sensed in terms of output shaft rotational speed. Arm extension and retraction can be under the control of any suitable sensing means, however. For example, wind speed could be sensed independently of the power source and a signal corresponding to the sensed wind speed could be used to control the arm extension through electro- mechanical control arrangements if preferred. Braking means, for example hydraulic but preferably electro¬ magnetic braking means, acting on the output shaft 2 for retracting rotation can also be provided.

Each of the vane structures 12 comprises first and second vane portions 24,25, each conveniently of rectangular shape, the vane portions being hinged

OMPI together along adjacent longer sides. Each inner vane 24 is carried at the free end of the associated arm portion 15. The connection to the arm portion 15 can be such as to permit pivotation of the vane portion 24 about a horizontal axis at right angles to the axis of the arm to allow movement in response to wind conditions, but the position of the connection is such that the vane portion is gravitationally urged to lie at least approximately vertically. This is the vane structure position in normal use, in which the hinged axis between the vane portions is substantially vertical. In this embodiment, the inner vanes 24 extend tagentially to the circle described by the free upper ends of the arms 11 during rotation. However, in a modified embodiment, the inner vanes 24 are inclined at a small angle to the tangent to the circle.

The operation of the vane structure 12 will appear from Figure 2, in which only the vane structures and the adjacent parts of the arm portions 15 are shown. With a wind direction as indicated by the arrow 26, the output shaft 2 rotates in the direction of the arrow 28. The vane structure 12 directly opposed to the wind direction, that is, on the right of Figure 2 is in the closed condition because the wind blows the vane portion 25 against the vane portion 24. During rotation through the next 90°, however, the wind entering between the vane portions, and the centrifu¬ gal force acting on the vane portions 25, cause the latter to pivot outwardly to a position of maximum angular displacement, defined by stop means (not shown) , at which the angle between the vane portions may be for example 45°. As the vane structure 12 moves further clockwise (as shown) it will tend to remain open to beyond the second position at which the vane portion 24 is normal to the wind direction, until wind pressure, after this position has been passed, tends to effect closure, which will be substantially complete when the vane structure

OMPI has reached a position opposite that at which it was fully open. There is consequently maximum wind catchment for each vane structure 12 at the uppermost position of Figure 2 and the rotational effect of this is opposed in the lowermost position only by the effect of the wind on a vane structure in position for mini¬ mum wind catchment. The vane structures 12 thus present wind impingement areas which are dependent on the attitude to the wind of the supports on which they are carried, in. such a manner as to enhance the energy collected from the wind.

The vane structures 12 can take a variety of different forms according to requirements. The relative areas of the vane portions 24,25 can be varied and the vane portion 25 differently positioned horizon¬ tally and/or vertically relative to the vane 24. More than one pivotally mounted vane portion can be provided. The vane portions of each vane may be pro¬ vided with resilient biassing means opposing the opening movement of the vane portions 24,25. These means may take the form of one or more tension springs, which may be provided with dampers, for example hydraulic shock absorbers.

A second wind-driven power source 110 embodying the invention is shown in Figures 3 to 5. The power source 110 has a hollow rotatable one-piece output shaft 102, of about 50mm outside diameter and about 9.5mm wall thickness, which is journalled in suitable bearings (not shown) within an upper tubular column 104 and a lower tubular column 106 which extend above and below a support structure such as the deck 108 of aboat or ship, the columns 104,106 having an external diameter of about 130mm. The columns 104,106 are secured to the deck 108 by bolts (not shown) passing through end flanges 112,114 of the columns and the shaft 102 passes through an aperture 115 in the deck 108. For further stability, the upper column 104 is also stayed by steel cables (not shown) extending to the deck 108. The output shaft 102 is secured at its upper end to a circular steel plate 116 on which four vane-support arms 118 are mounted at equally-spaced intervals, only one such arm being shown in Figures 3 and 4. Each arm 118 is secured to the plate 116 by a pair of hollow, semi-cylindrical shells 120,121, of which a lower one 120 is welded to the plate 116 and an upper one 121 is bolted by bolts (not shown) to the lower shell 120 to secure the associated arm 118.

An annular steel support 119 is welded to the upper column 104 adjacent the top of the column 104. The annular support 119 has six equally-spaced upwardly- extending brackets 120, only being shown in Figure 3. Each bracket carries at its upper end a roller 121 which contacts the upper surface of the plate 116 and restrains the latter against movement out of its horizontal plane. The brackets 120 are removable from the annular support 119 to allow the circular plate 116 to be fitted to the shaft 102.

On its underneath face the circular plate 116 has an annular flange 122, around the outer surface of which a brake band 123 can be tightened to brake rotation of the shaft 102. The brake band 123 is connected by a linkage (not shown) to an operating lever 129 on the upper column 104.

Each vane-support arm 118 is extensible and contractible and has an inner portion 124 and an outer portion 125 slidable telescopically on a bearing (not shown) of plastics material within the inner portion. A guide wheel 174 mounted at the inner end of the outer arm portion 125 further supports and guides the outer portion 125.- The outer ends of adjacent inner arm portions 124 are linked by bracing members 126.

-W EX_f

OMPI Each outer arm portion 125 carries at its outer end a vane 127 which is pivotally mounted on the outer arm portion 125 and comprises an open steel framework 128 which supports a covering of plywood or fibreglass or other suitable material providing wind-engagement surfaces of the vane. Each vane 127 comprises a first, inner vane portion 130 and a second, outer vane portion 131, the vane portions each being part-circular cylindrical in shape, and arranged with their cylinder axes extending vertically and mutually parallel and with their concave faces facing each other. The two vane portions 130,131 of each vane 127 are hinged together along their vertical edges which lead during rotation of the arms 118 and thus operate in a manner similar to that described with reference to Figure 2 for the first wind-driven power source 10.

The vanes 127 are completed by oval-shaped top and bottom plywood closure members 136 attached to the inner vane portions 130. Resilient biassing means may be provided between the vane portions 130,131, to operate in the manner described above for the first power source. In this embodiment, the outer vane portions 131 extend over approximately one-half of the width of their associated inner vane portions 130 but, in modified embodiments, the outer vane portions may be of sufficient width to meet their associated inner vane portions at the trailing edges of the vanes, or may be of some other width greater or less than that of the outer vane portions 131 of the embodiment described.

For further rigidity of the vane structure and to prevent rotation of the outer arm portions 125 within the inner arm portions 124, the outer ends of adjacent pairs or outer arm portions 125 are linked by telescopic connecting members 138,each of which comprises a rod 140 slidable within the tube 142, the rod 140 of each connecting member 138 being attached to one outer arm portion 125 of each adjacent pair, whilst the tube 142 is attached to the other outer arm portion

O PI 125 of the pair. Inside each telescopic connecting member 138, a spring 143 acts between the rod 140 and tube 142 and opposes extension of the connecting member 138. The rigidity of the vane structure is further enhanced by a similar arrangement of telescoping members extending between the vanes 127 themselves. In this case, four tubes are formed into a unit 144 having a four-pointed star shape and respective rods 146, each extending from one limb of the unit 144, are attached to the vanes 127 adjacent their points of attachment to the outer arm portions 125. Extension of the rods 146 from the tubes may again be opposed by springs 147 fitted within the tubes and acting between the rods 146 and the tubes 144. For control of the extension and contraction of the vane-supporting arms 118, a hydraulic cylinder 149 is mounted is mounted concentrically with the output shaft 102 above the plate 116. A piston 150 is slidable in the cylinder 149. A short distance below the plate 116, a pair of spaced seals 152 seal the clearance between the outer surface of the shaft 102 and the inner surface of the lower tubular column 106. Between the seals 152, the shaft 102 has two diametrically-opposed apertures 154 and the lower column 106 also an aperture 156, which is connected bya pipe 158 to a source of hydraulic fluid under pressure. The hollow interior of the shaft 102 is sealed at 157 below the apertures 154. By supply of hydraulic fluuid through the pipe 158 to the interior of the shaft and thence to the cylinder 149 by way of a connecting pipe 159, the piston 150 can be raised in the cylinder 149. The source of hydraulic fluid may be controllable by an operator of the power source, or may be controlled by a wind soeed sensor. The piston 150 is secured to the lower end of a rod 160 which extends from the cylinder 149 concentr- cally with the output shaft 102. The upper end of the rod 160 is attached to a further circular plate 162, to which four wire cables 164 for controlling the extension and contraction of respective ones of the arms 118 are attached at equal angular intervals, only one cable being shown in Figures 3 and 4. Each wire cable 164 extends downwardly from the further plate 162, around a pulley 166 mounted on the circular plate 116, upwardly to the further plate 1 2, around a further pulley 168 on the further plate 162, downwardly to another pulley 170 on the plate 116 and thence outwardly along the outside of the inner portion 124 of the respective arm 118. At the outer end of each inner arm portion 124, the associated cable 164 passes around a guide pulley arrangement 172 and into the interior of the inner arm portion 124 through the plastics bearing (not shown). The cable 164 then passes between the inner and outer arm portions 124,125 to the inner end of the outer arm portion 125, where it is anchored to the outer arm portion 125.

By increasing or decreasing the hydraulic pressure supplied to the piston 150 and cylinder 149 the piston 150 can be raised or lowered in its cylinder and, by the action of the four cables 164, the arms 118 are contracted and extended. During extension of the arms 118, the rods 140 of the telescopic connecting members 138 and the rods 146 slide relative to their associated tubes 142,144 against the bias of the asso¬ ciated springs as the distance between the vanes 127 increases. During contraction of the arms 118, the distances between the vanes 127 decreases and the rods 140,146 are retracted into their respective tubes by the action of the associates springs. Figure 6 of the drawings is a plan view of part of the vane structure of a third wind-driven power source embodying the present invention. The vane structure includes four extensible and contractible arms (not shown) which are identical to the four arms 118 of the second power source 110. However, each vane 127 of the second power source 110 is replaced by a pair of hollow hemis¬ pherical shells 184,186 of, for example, fibreglass material, mounted at the free upper end of each outer arm 125. The shells 184,186 are rotatable relative to each other on a mounting member 188 extending along a common diameter of the shells. The rigidity of the vane structure is enhanced by braces^' 190,192 connecting adjacent pairs of mounting members 188. One shell 184 of each part of shells is of slightly smaller diameter than a larger shell 186 so that the pair of shells 184,186 has a first condition in which it has a substantially continuous spherical outer surface and a second condition in which the smaller shell 184 lies completely inside the larger shell 186 and the pair of shells form a hollow hemispherical shape with a circular opening lying in a vertical plane which also contains the respective arm 182. In this connection, the inner surface of the smaller shells 184 constitute wind engaged surfaces of the power source.

The arm 182 of this power source are extensible and contractible in a similar manner to those of the second power source and each have a wire cable controlling the extension and contraction. The mounting members 188 are pivotally-attached to the outer vane-support arms and the braces 190 so that, upon extension and contraction of the vane-support arms, the upper ends of the mounting members are able to pivot towards and away from the central axis of the vane structure. By suitable routing of the cable, the relative movement

O PI ^Λr of the hemispherical shells 184,186 can be arranged to take place upon extension and contraction of the arms 182, so that the shells 184,186 are in their first condition when the arms 182 are contracted and adopt their second condition when the arms 182 are extended. In a modified form of this embodiment, each pair of hemispherical shells 184,186 is replaced by a single hemispherical shell orientated with its open circular face in a vertical plane extending radially from the axis of the vane structure. These hemispherical shells may be further modified by apertures therein, possibly of adjustable area. In further modifications of this embodiment, the hemispherical shells are replaced by hollow members of any hollow bowl or other shape. The ship 30 shown schematically in Figure 7 has two of the wind driven power sources 10 of Figures 1 and 2 mounted on its' deck, one at the bow and the other at the stern. The power sources 10 may be replaced by power sourcesdescribed with reference to Figures 3 to 6. The ship 30 is propelled by a propeller 31 on a propeller shaft 32, or by more than one propeller, or by one or more hydrojets if preferred, and in accordance with the invention, the power sources 10 are directly mechanically coupled to the or each propeller shaft 32. As shown, the output shafts 2 of the two power sources 10 are connected through appropriate gear connections 34 to a shaft 35 extending longitudinally of the ship, and a geared connection 36 connects this shaft through a gear box 38 to the propeller shaft 32. The gear box 38 and/or the gear connections 34,36 are arranged to provide an appropriate transmission ratio between the output shafts 2 and the propeller shaft 32, specifically to provide a speed step up, and the gear box provides for selective adjustment of the transmission ratio, and for reversal of the rotational direction of the propeller shaft between the power device output shafts

- 15 -

2 and the propeller shaft. A clutch is also provided to permit the shaft 35 to be decoupled from the gear box 38 and clutches are also preferably provided between the output shafts 2 and the shaft 35. To permit propulsion of the vehicle in the absence of any wind adequate to drive the power sources 10, an electric motor 40 can be selectively coupled by means of a clutch to the gear box 38 to drive the propeller shaft. Power for driving the motor 40 is then derived from or more batteries 42, which may be charged by power derived from solar cells 44 carried on a deck surface of the vessel. The batteries 42 can also be caharged by power derived from the power sources 10 and for this purpose a dynamo or generator 45 can be selectively driven from the longitudinal shaft 45 through a gear connection 46 by closure of a clutch associated with this gear connection- The electrical connection between the batteries 42 and the motor 40 can incorporate a diode or other rectifier means to block feedback.

Figure 8 of the drawings is a schematic plan view of a further marine propulsion system e bodyiing the invention. The figure shows the outline of a ship or boat 200 which is fitted with two wind-driven power sources, which may be of any of the types described above, one on the fore deck and one on the after deck. The drive from the power source adjacent the bow is fed to a 50:1 step-up gear box 202, mounted below the power source and having an output shaft 204 extending centrally of the ship towards its stern. The drive from the other power source is similarly fed to another

50:1 step-up gearbox 206 positioned in the stern of the ship and having an output shaft 208 extending centrally of the ship towards its bow. The output shafts 204,208 drive respective variable ratio hydraulic transmissions 210,212, which provide further speed increases of between 1:1 and 3:1. The transmissions 210,212 are coupled by shafts 214,216, including pairs of universal joints 218,220, to respective gearboxes 226,228 mounted amidships to the starboard and port sides of the ship. Each gearbox 226,228 drives a combined DC motor and generator 230 or 232 of the type having electrically-excitable field coils by way of a respective toothed belt 234 or 236. The gearboxes 226,228 also have output shafts 238,240 leading to respective propellers 242,244. The output shafts 238,240 may include clutches for interrupting the drive to the propellers 242,244 and also further step- up gearing with a ratio of, for example, 2:1. The propellers 242,244 are advantageously variable-pitch propellers. *

The combined motors and generators 230,232 are each connected toa bank 246 of eighteen 12V storage batteries and to a suitable electrical control system (not shown) . The control system produces a selected one of four pre-set DC voltages for driving the units

230,232 at one of four pre-set speeds. The motor power of the units for a 45ft motor boat can be, for example, 5.5kW and the maximum voltage supplied 200V.

Each gearbox 226 or 228 can be controlled selec- tively, for example, from the helm of the ship or boat, to couple the power sources directly to the propellers 242,244, to the motor and generator units 230,232, or to both the propellers 242,244 and the units 230, 232 simultaneously. Thus, by appropriate control of the gearboxes 226,228 and the control circuits of the units 230,232, the propellers 242,244 can be driven directly by the wind-driven power sources when sufficient wind power is available, the propellers 242,244 can be driven by the units 230,232 acting as motors when insufficient ^" wind power is available, the batteries can be charged from the units 230,232 driven as generators by the

OMPI wind-driven power sources when the boat is stationary and, if sufficient wind-derived power is generated, the propellers 242,244 can be driven directly and the batteries charged simultaneously. A battery-charging unit may be added for charging of the batteries from an external source of electricity.

If desired, control of the gearboxes 226,228, the generator and motor units 230,232, variable ratio transmissions 210,212 and, when the wind-driven power sources are as described above with reference to Figures 1 to 7, the extension and contraction of the vane support arms, may be controlled by a micro-computer-based control system which may also incorproate equipment such as the ship's or boat's compass, a position finder, an auto- pilot etc.

It will be appreciated that the rotational motion of the output shafts of the wind-driven power sources of the ships or boats of Figures 7 and 8 can be applied directly to the propulsion means by way only of mechanical or hydraulic transmission elements. Thus, marine vessel according to the invention can be propelled without the use of any electric motor or generator.

It will also be appreciated that features of the embodiments and modified embodiments described may be used or further embodiments in combinations different from those described without departing from the scope of the invention.

OMPI

Claims

Claims :

1. A wind-driven power source having an output shaft driven byrotatable arm means carrying and/or constituting wind-engaged surfaces, the source including means for modifying the shape and/or aspect of the wind-engaged surfaces in response to changes in wind speed.

2. A power source according to claim 1 , in which the arm means comprise one or more extensible and contrac¬ tible arms, the source including wind speed sensing means operatively connected to control means arranged to change the effect length of the arm(s) in response to changes in wind speed.

3. A wind-driven power source having an output shaft driven by rotatable arm means carrying and/or constituting wind-engaged surfaces, the arm means comprising one or more arms which are extensible and contractible for change of their effective lengths.

4. A power source according to claim 3, including control means operable by an operator of the power source to change the effective length of the arm(s) .

5. A power source according to claim 3, including wind speed sensing means operatively connected to control means arranged to change the effective length of the arm(s) in response to changes in wind speed.

6. A power source according to claim 2, 4 or 5, in which the control means comprise a hydraulic piston and cylinder arrangement and a mechanical linkage for transmission of movement of the hydraulic piston to effect extension and contraction of the arm(s) .

7. A power source according to claim 2 or 5, in which the wind speed sensing means is responsive to the rota¬ tional speed of the output shaft.

8. A power source according to claim 7, in which the wind speed sensing means comprises one or more weights movable under the action of centrifugal force during rotation of the output shaft.

9. A power source according to claim 2, 5, 7 or 8, in which the control means are arranged respectively to increase and decrease the effective length of the arm(s) in response to decreases and increases in wind speed.

10. A power source according to any one of claims 2 to 9, in which the or each arm comprises first and second telescopically slidable portions.

11. A power source according to any one of claims 2 to 10, having a plurality of arms extending upwardly and outwardly from a substantially vertical shaft driven to rotate by rotation of the arms.

12. A power source according to any preceding claim, in which the arm means carry at least one vane comprising a first vane member attached to the arm means and a second vane member pivotally mounted on the first member, the vane members being pivotable relative to each other between a closed position in which the vane members lie adjacent each other and an open position in which the members are spaced apart at their edges which trail during rotation of the arm means.

13. A power source according to claim 12, in which the first and second vane members are each substantially planar.

14. A power source according to claim 12, in which the first and second vane members are each part cylindrical and arranged with their axes mutually parallel and their concave faces directed towards each other.

15. A power source according to any one of claims 12 to 14, in which the first and second vane members are relatively pivotable about a substantially vertical axis.

16. A power source according to any one of claims 12 to 15, including resilient biassing means urging the first and second vane members into their closed position.

17. A power source according to any one of claims 1 to 11, in which the arm means carry at least one vane comprising a hollow member having an internal wind-engaged surface.

18. A power source according to claim 17, in which the hollow vane member has a substantially hemisperhical shape.

19. A power source according to claim 18, in which the vane comprises first and second hollow hemispherical members which are relatively rotatably about a common diameter from a first condition in which they provide a substantially continuous spherical surface and a second condition in which one member is received in the other member to provide a concave hemispherical wind- engaged surface.

20; A marine vessel having one or more wind-driven power sources each having a rotational output shaft, the vessel including transmission means operable to couple the or each output shaft to a propulsion means of the vessel.

21. A vessel according to claim 20, including electrical genreator means, means for storage of electrical power generated by the generator means, and electric motor means capable of being powered by the storage means, the transmission means being operable in a first condition in which the or each output shaft is coupled to the propulsion means to power the vessel, in a second condition in which the or each output shaft is coupled to the electrical generator means and generated electrical power can be sotred in the storage means, and in a third condition in which the electric motor means are powered by the storage means and are coupled to the propulsion means.

22. A vessel according to claim 21, in which the transmission means is operable in its first and its second conditions simultaneously.

G?/!PI

23. A vessel according to claim 21 or 22, in which the generator means and motor means comprise a combined

DC motor and generator.

24. A vessel according to any one of claims 20 to 23, in which the transmission means includes step-up gearing.

25. A vessel according to claim 24, in which the ratio of the step-up gearing is selectively variable.

26. A vessel according to any one of claims 20 to 25, in which at least one wind-driven power source is in accordancewith any one of claims 1 to_v 19.