TECHNICAL FIELD This invention relates to an air or water driven propeller and/or a power generating device.

It is an object of the invention to provide a propeller and/or a power generating device which will at least provide the public with a useful choice.

BACKGROUND ART

Water or air driven propellers used to generate power are known. However, these are often enclosed by mounting means such as that shown in New Zealand patent no. 189563. Furthermore, power generating devices using a propeller to generate electricity are known. The propeller can be air or water driven.

DISCLOSURE OF THE INVENTION

The foregoing the invention consists in a propeller comprising; a shaft; a plurality of vanes; said vanes mounted on said shaft; said plurality of vanes comprising arcs of substantially the same configuration and dimensions; said plurality of vanes not being substantially enclosed, or surrounded by, any mounting means in use. Furthermore, the invention consists in a power generating device comprising a housing and a plurality of propellers, said propellers being driv ^e n by air or water in use and electricity generating means.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred form of the invention will now be described with reference to the accompanying drawings in which;

Figure 1 is a diagrammatic perspective view of a propeller according to one preferred form of the invention.

Figure 2 is a plan schematic view of a propeller according to one preferred form of the invention.

Figure 3 is a sectional plan view of a tidal power generating device according to one preferred form of the invention. Figure 4 is a sectional end elevation of the tidal power generating device of

Figure 3 according to one preferred form of the invention.

Figure 5 is an exploded view of detail A of Figure 4 at installation of the roller spring assembly.

Figure 6 is an exploded view of detail A of Figure 4 as shown in Figure 5 but wherein the roller spring assemblies are ready for use.

Figure 7 is an exploded view of detail B of Figure 3 according to one preferred form of the invention.

Figure 8 is a sectional end elevation of a control door. Figure 9 is a sectional plan view of the control door shown in Figure 8. Figure 10 is a sectional elevation of a shallow sea water power generating device according to an alternative preferred form of the invention. Figure 11 is an exploded view of detail C in Figure 10. Figure 12 is a sectional plan view of the shallow sea water power generating device of Figure 10. Figure 13 is a sectional side elevation of the control door showing a structural joint

Figure 14 is a plan view of the structural joint shown in Figure 13. Figure 15 is a sectional plan view of an aircraft incorporating several propeller according to one embodiment of the invention. Figure 16 is a sectional side elevation through line A-A of Figure 15.

Figure 17 is a sectional end elevation of a river power generating device according to one embodiment of the invention.

Figure 18 is a sectional plan view of the river power generating device of Figure 7 .

BEST MODES FOR CARRYING OUT THE INVENTION

The invention in one aspect relates to a propeller 1. The propeller 1 has a central shaft 2 with a plurality of vanes 3 mounted thereon. The plurality of vanes 3 comprise arcs of substantially the same configuration and dimensions. The radius of the arcs can be varied as shown in Figure 2 so that the overall dimensions of the propeller 1 can be adjusted as required.

The vanes 3 or arcs have a defined angle of curvature. This is illustrated in Figure 2. A first line 6 can be drawn between the distal end 4 and proximal end 5 of the vane 3. The proximal end 5 of the vane 3 is attached to the shaft 2. A second line 7 can be drawn from the proximal end 5 which forms a tangent with the proximal part 8 of the vane 2. The angle 9 between the first and second lines 6 and 7 is desirably between 10 to 30° and preferably substantially 20°. Between two to seven vanes 3 are desirably mounted on the shaft 2. In the desired form of the invention, six vanes 3 are mounted on the shaft 2. If six vanes 3 are mounted on the shaft 2, the chords 10 between the distal ends 4 of adjacent vanes 3 are substantially equivalent in length to the radius of the circle 11. The circle 11 can be drawn so that it substantially contacts each distal end 4 of each vane 3.

The propeller 1 is desirably formed from light-weight material such as aluminium or the like. The propeller 1 may for example be up to 2 metres long or more. The vanes 3 are not substantially enclosed, or surrounded by, any mounting means in use. This can be seen more clearly by reference to Figures 4, 10 and 16. Only the shaft 2 need be pivotally mounted on the power generating device.

The propeller 1 is driven by water and/or air. The shaft 2 is connected by gears to an electrical generator (not shown). Thus power can be produced by the device. Power generating devices shall now be described which incorporate one or more propellers, as described above. Figures 3 to 7 show a tidal power generating device. The device is elongate horizontally and can be provided substantially adjacent low tide level along a beach for example. For example, the power generating device may be mounted under or alongside an existing bridge over a tidal estuary or a tidal bay. Alternatively, an

- 4 - estuary may be walled off and the power generating device provided in the walled off parts thereof or may form part of the wall. The power generating device can be provided adjacent a control door to be described later. Thus, a row of tidal power generating devices and control doors can be provided substantially adjacent low tide level. Alternatively, the control doors can be positioned on the open sea side of the power generating devices so as to adjust sea level adjacent the power generating devices as required.

The power generating device has a height adjustable float member 13. The float member 13 may be elongate horizontally. A cross-section of the float 13 shows that it may have a neck portion 14 and circular base portion 15. However this is only one embodiment of the float member 13 and other embodiments are clearly envisaged within the scope of the invention. At least one propeller 1 is attached to the tidal power generating device. The propeller 1 or propellers 1 are attached to the float member 13 for example. In the embodiment shown, a pair of propellers 1 are provided which are elongate horizontally. Several pairs of propellers 1 may be provided along the width of the float. The propellers may for example each be connected to an electrical generator by gears. These features are not shown. The float 13 may be provided within a housing 16 and may be substantially attached thereto. For example, bracing members 17 may be provided which connect the float 13 to the housing 16.

Height adjustment means are provided so that the height of the float 13 can be varied in response to changes in sea level. The height adjustment means may comprise rollers 18 which may be provided on the housing 16. These may be similar to those shown in Figure 6, to be described later herein. Support members 20 may also be provided and these may be positioned adjacent the tidal power generating device. The rollers 18 may for example run on the support members 20. The support members 20 may for example be formed out of concrete or the like material and may also serve to break up wave action.

A pump 20 is provided in the float 13 and this enables the water level 21 in the float 13 to be adjusted. Accordingly, this can control the height of the float 13.

The apparatus has a base 22 which in the preferred form of the invention has a elongate groove 23. The base 22 may also have an aperture 24 which is large enough so that a diver can carry out maintenance on the lower parts of the

apparatus.

A telescopic height adjustment member 25 may be positioned in the groove 23. Rollers 26 may be provided adjacent the lower parts of the telescopic height adjustment member 25. The rollers 26 may for example be able to bear against the inside faces of the groove 23 in use.

The rollers as shown in detail A of Figure 4 are shown more clearly in Figures 5 and 6.

Springs 28 are provided which bear against the rollers 26. The springs 28 may for example be packed with grease in plastic bags in order to reduce corrosion thereof. In the embodiment of Figure 5, the roller spring assemblies (26 and 28) are shown at installation wherein there is a cover plate 29 provided over the housing 30 of the roller spring assemblies 26 and 29. Once the cover plate 29 is removed, the spring 28 bears against the roller 26 so that it is able to contact the inside face of the cavity 23. Rubber buffers 31 may be provided adjacent the lower parts of the telescopic height adjustable member 25. These may serve to substantially stabilise the telescopic height adjustable member 25 against wave movements. Seals 32 may be provided to attach the components as shown in Figures 5 and 6.

The float 13 is attached to the telescopic height adjustable member 25. For example, an attachment member 34 may be provided adjacent the lower parts of the float 13. This may have a curved upwardly facing surface within which the lower parts of the float 13 are positioned and adhered to.

A bolt 36 may pass through the attachment member 34 and the telescopic height adjustable member 25. Further bolts 37 may be provided on either side of the telescopic height adjustable member. These may serve to reduce stress fracturing and hold flap seals 38.

The apparatus may cause the formation of a weir wherein the water level at 39 for example is higher than that at 40. The structure of the device is symmetrical and two sets of propellers 1 are provided. For example, when the tide is going in to shore the water will flow over the float 13 and propel the right hand propeller 1.

When the tide is going out the left hand propeller can be turned. Gates 41 may

be provided adjacent the upper parts of the float 31. These can be opened or closed as desired, to direct the water flow to either of the propellers 1.

Turning now to Figure 3, further support members 42 may be provided adjacent each end of the float 13. These may have longitudinal slots 43 and vertical tongues 44 may be provided on the outer ends of the float 13 which are positionable in said grooves 43. Figure 7 shows an exploded view of detail B in Figure 3. This shows a seal which is secured by screws 45 for example to the tongue 44. The seals have a spring 47 which bears against a pressure member 48. The pressure member 48 may for example be half circular and formed from metal or plastic. The spring assembly is provided in a casing 49.

The lower parts of the tidal power generating device may be provided in three sections. For example, these are identified as sections 50 to 52 in Figure 3. Each of the sections 50 to 52 are bolted together. The sections 50 to 52 may for example be substantially 7 metres long. The tidal power generating device may be provided adjacent to or in conjunction with a device able to adjust sea level. This is shown in Figures 8 and 9. This is similar to the power generating device in that it has a base 54, float 55 and a housing 56. The housing 56 has rollers 57 and these run on support members 58 provided on either side of the apparatus. Rollers with springs similar to those shown in Figure 6 could be used if desired. However, apertures 59 and 60 are provided on either side of the float 55. These are covered by doors which are able to be opened or closed. Thus, the water level 61 in the float 55 can be altered. If required, a pump (not shown) may also be provided to vary the water level 61 in the float 55. The float 55 is attached to a attachment member 62 and may be attached to the housing 56 by bracing members 63. A seal 64 is provided between the base 54 and the attachment member 62. Thus, when the float 55 is filled with water to the required amount, the upper parts of the sea level adjustment device are attached to the base 54 and water is unable to pass to shore. The seal 64 ensures that water does not escape through the connection between the upper and lower parts of the device. However, when the upper parts of the sea level adjustment device are lifted, water can pass freely to shore or back to sea.

The float 55 also has elongate tongue members 65 positionable in grooves 66 in

the support members 67 provided at either end of the apparatus. Again, the lower parts of the device can be made in three sections 50 to 52.

Figures 10 to 12 show an alternative embodiment of the power generating device. This is suitable for use at shallow sea water levels as it is somewhat compacted in height. Most of the features of this device are similar to that described earlier for the tidal power generating device. The major difference is that the float 66 also forms the telescopic height adjustment member. Thus, spring roller assemblies are provided adjacent the lower parts of the float 66. These are shown in more detail in Figure 11. The base 22 must of course include a wider horizontal slot 67 within which the float 66 can be positioned in use.

As discussed earlier, the lower parts of each of these devices can be provided in three parts 50 to 52. Structural joints are used to connect each part. These structural joints are shown in Figure 13 and 14. As shown, the parts 51 and 52 may be angled when viewed in plan. This enables ease of assembly in that the last parts to be inserted can slide into place. Figure 13 is a sectional side elevation of the lower parts of the power generating device shown in Figure 4. The lower seal 31, rollers 26 and upper seal 38 are shown. Vertical seals 69 should also be provided. The structural joint 70 is shown in more detail in Figure 14.

A seal 71 should be provided at the connection point between the two components. Attachment members 72 are provided to attach the two components. Figures 15 and 16 show one embodiment of the invention wherein the propellers 1 are air driven. In this embodiment, a plurality of propellers 1 are provided in an aircraft 73. As shown in Figure 16, the propellers may be provided in graduating height.

Finally, we turn to Figures 17 and 18 which show a river power generating device. The device incorporates at least one propeller 1 and has an inlet 75 wherein the water is fed to the propeller 1. The generator may be provided at the top of the apparatus in the box 76 for example.

Figure 18 shows a sectional plan view of the propeller where the water is fed from the inlet 75 to the propeller 1. The river powered generating device has a base 76.

INDUSTRIAL APPLICABILITY

Thus it can be seen that in at least the preferred form of the invention a propeller is provided which has a defined shape and configuration. The vanes are provided having a suitable angle of curvature and are able to be rotated by water or air very efficiently.

The invention also relates to a tidal power generating device which is height adjustable and therefore able to take into account changes in sea level. Also, the propellers provided are able to be driven by sea water going into shore and back out to sea. The device is able to generate electricity from natural resources such as water and thus reduces pollution to the environment

The invention also relates to a river power generating device and an aeroplane incorporating a plurality of propellers as hereinbefore described and having advantages as discussed above.