AU2006203209A1 - Water directing foil - Google Patents

Description

t AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION

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\O NAME OF APPLICANT(S):: Roger Douglas Hamilton ADDRESS FOR SERVICE: DAVIES COLLISON CAVE Patent Attorneys 255 Elizabeth Street, Sydney, New South Wales, Australia, 2000 INVENTION TITLE: Water directing foil The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5102 WATER DIRECTING FOIL STechnical Field C [001] The present invention generally relates to directing, stabilising or performance components or devices on watercraft for directing the flow of water as the watercraft Cc traverses through, partially through or on top of a body of water, and more particularly to a Sfoil, and/or a fin integrally formed with a foil, for use with watercraft.

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ri [002] The present invention relates to a foil and/or a fin integrally formed with a foil for use with watercraft such as surfboards, surf-skis, sailboards, kayaks, canoes, skiffs, waterskis, windsurfers, sailboards, body boards or the like or any other fully or partially submerged watercraft.

Background Art [003] Although the following discussion is in respect of surfboards, the present invention should not be considered to be limited in application only to surfboards. It is known to use various configurations of fins on the underside of a surfboard to improve the stabilising, performance or turning ability of the surfboard. For example, it is known to provide a trifin thruster) type arrangement for a surfboard comprising outer fins and a central fin.

During a turn the outside fins of the surfboard can only displace a given amount of water, or alternatively can only exert a given force on the water, related to the size of the fin.

Larger fins can reduce the maneuverability of a surfboard making the surfboard harder to turn. Additionally, a significant amount of energy can be wasted during a turn in the form of jettisoned water spray.

[004] Various configurations of surfboard fins have been devised, however, continued improvements relating to the turning, stabilising, or performance effects of fins, or associated components or devices, are desired by watercraft users.

[005] This identifies a need for a foil and/or a fin integrally formed with a foil which addresses or at least ameliorates problems inherent in the prior art.

c [006] The reference to any prior art in this specification is not, and should not be taken Zas, an acknowledgment or any form of suggestion that such prior art forms part of the common general knowledge.

Disclosure Of Invention [007] According to a first broad form, the present invention provides a foil for use with a INC watercraft, the foil including: a first surface; a second surface; a first edge forming part of a leading portion of the foil, the first edge formed between or by the first surface and the second surface; a lateral edge, adjacent the first edge, and forming part of a trailing portion of the foil, the lateral edge formed between or by the first surface and the second surface; and, a second edge formed opposite the first edge and the lateral edge, the second edge formed between or by the first surface and the second surface.

[008] According to a second broad form, the present invention provides a foil for use with a watercraft, the foil including: a leading portion including a first edge, at least part of a second edge opposite the first edge and a leading edge formed between the first edge and the second edge; and, a trailing portion including a lateral edge adjacent the first edge, at least part of the second edge and a trailing edge formed between the lateral edge and the second edge.

[009] According to specific, but non-limiting, further examples: the first surface may be substantially planar or substantially curved; the second surface may be substantially planar or substantially curved; the leading portion may taper towards the first edge; the leading portion may taper towards the leading edge; the trailing portion may taper towards the trailing edge; the trailing portion may increase in cross-sectional area towards the trailing edge; the leading portion and/or the trailing portion may taper towards the second edge; the trailing portion may taper towards the lateral edge; the trailing portion may increase in cross-sectional area towards the lateral edge; N, the lateral edge may be substantially one dimensional in extent; Zthe lateral edge may be substantially two dimensional in extent, for example substantially planar or substantially curved; the lateral edge may be formed by a joining of the first surface and the second surface; the lateral edge may be a distinct surface contiguous with the first surface and the second surface; INO the lateral edge may taper contiguously into the first edge; the lateral edge and the first edge may together form a single combined edge; the lateral edge and the first edge may together form a single combined edge that is substantially straight; a shoulder may be provided between the first edge and the lateral edge; and/or, the first edge may or may not be parallel or co-planar with the lateral edge.

[010] In a further optional form, the foil can be provided with attachment means to attach the foil to the watercraft and/or to a fin. Alternatively, the foil may be provided with attachment means to hold the foil between a fin and the watercraft by relying on the attachment means of the fin to the watercraft.

[011] In a further optional embodiment, the foil may be twisted or rotated along a longitudinal axis of the foil.

[012] In various embodiments the foil can be provided as a stand alone device for postattachment to a fin and/or the watercraft, or may be provided integrally formed with a fin, or provided integrally formed with attachment means provided on the watercraft, for example integrally formed with receiving plugs embedded within a surf craft which receive tabs of a fin for attachment of the fin to the surf craft.

[013] In accordance with still further optional example forms: the foil may be attached to or associated with an outside fin by attaching to or associating with the surface of the outside fin nearest the central longitudinal axis of the watercraft; the trailing edge extends past a trailing fin edge; O the leading edge extends past a leading fin edge; Sthe trailing edge ends at the trailing fin edge; the leading edge ends at the leading fin edge; the trailing edge does not extend past the trailing fin edge; the leading edge does not extend past the leading fin edge; and/or, the foil may be attached to or associated with both a first fin surface and a second Sfin surface.

IND [014] According to a preferred form, a longitudinal plane of the foil forms an acute angle 0 10 with the surface of the watercraft to which the foil and/or the fin is attached.

[015] According to still a further optional form, two foils are associated with a single fin, each foil extending from opposing fin surfaces near a fin base region.

[016] According to a third broad form, the present invention provides a fin for use with a watercraft, the fin including: a fin section formed by a first fin surface and an opposite second fin surface, the first fin surface and the second fin surface forming a leading fin edge and a trailing fin edge, the fin section also including a fin base region near where the fin attaches to the watercraft; and, a foil section integrally formed with the fin section near the fin base region, the foil section protruding laterally from the first fin surface at an acute angle to the surface of the watercraft near the fin base region.

[017] In accordance with a specific embodiment, the foil section of the fin includes a first surface, a second surface, a first edge forming part of a leading portion of the foil, the first edge formed between or by the first surface and the second surface, a joined section attached to or forming part of the fin base region, the joined section adjacent the first edge and forming part of a trailing portion of the foil, the joined section formed between the first surface and the second surface, a second edge formed opposite the first edge and the joined section, the second edge formed between or by the first surface and the second surface.

Brief Description Of Figures [018] An example embodiment of the present invention should become apparent from the following description, which is given by way of example only, of a preferred but non- (,i limiting embodiment, described in connection with the accompanying figures.

N [019] Fig. 1 illustrates an underside perspective view of the rear of a surfboard having a tri-fin arrangement with foils attached to or associated with outside fins of the surfboard;

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S 10 [020] Fig. 2 illustrates an example side view of a foil attached to or associated with a fin; (,i [021] Fig. 3 illustrates an top plan view of an example foil attached to or associated with a fin; [022] Fig. 4 illustrates a front plan view of an example foil attached to or associated with a fin; [023] Fig. 5 illustrates a perspective view of an example foil that may be attached to or integrally formed with a fin; [024] Fig. 6 illustrates a plan view of the foil illustrated in Fig. [025] Fig. 7 illustrates a perspective view of an example fin integrally formed with a foil; and, [026] Figs. 8(a) to 8(f) illustrate top and side views of additional example configurations of foils or fins integrated with foils.

Modes for Carrying Out The Invention [027] The following modes, given by way of example only, are described in order to provide a more precise understanding of the subject matter of a preferred embodiment or embodiments.

[028] In the figures, incorporated to illustrate features of example embodiments, like N, reference numerals are used to identify like parts throughout the figures.

t [029] Referring to Fig. 1, there is illustrated the underside, i.e. opposite the deck, of a rear section of a surfboard 10. Although the preferred embodiment is described in respect of a Ssurfboard it should be appreciated that the present invention is applicable to any form of watercraft. Attached to surfboard 10 are fins 12a, 12b and 12c. Fins 12a and 12b are termed outside fins while fin 12c is termed a central fin. It should be appreciated that the INDpresent invention is not limited to use with a tri-fin arrangement but can be applied in a variety of one or more fin configurations on a watercraft.

[030] Means for attaching fins 12a, 12b and 12c to surfboard 10 are well known. For example, tabs can be provided with fins that are received by plugs in a surfboard or a fin or fins may be simply fibreglassed to a surfboard.

[031] Foils 14a and 14b are attached to or associated with outside fins 12a and 12b respectively. Foils 14a and 14b may be post-attached to a surfboard with existing fins, or a foil 14a or 14b may be provided integrally formed with a fin, or foils 14a, 14b may be provided integrally formed with attachment means of a surfboard (such as fin plugs).

When integrally formed with a fin, foils 14a, 14b form a foil section of a complete fin.

[032] In the embodiment where foils 14a, 14b are stand-alone devices, foils 14a, 14b may be attached to a fin, to the surface of a surfboard, to both a fin and the surface of a surfboard, or attached between the fin and the surface of a surfboard. For example, foils 14a, 14b may be glued, fibreglassed or otherwise held, by applying suitable setting, hardening or curing means to the foil, fin and/or surfboard. Alternatively, or if appropriate additionally, foils 14a, 14b can be provided with protruding members, tabs, rings, eyelets, sections, etc., which are held between a fin and the surface of surfboard 10 using known attachment means of a fin to surfboard [033] Foils 14a, 14b may be integrally formed with a fin receiving mechanism, for example fin receiving plugs or plug, fixedly held in surfboard 10. This would allow a standard fin (for example a Fin Control Systems TM fin) to be inserted and held in a combined foil/plug device embedded in surfboard

I

N, [034] Additional free-standing foils, or a foil, could also be attached directly to the surface of a surfboard away from a fin, for example in location 16.

,1 [035] Referring to Fig. 2, a side plan view of an example arrangement of fin 12a and foil 14a is illustrated. In this and the other example forms illustrated the foil should be N, considered to be a separate device to the fin or integrally formed with the fin. A trailing edge 22a of foil 14a is illustrated to extend as far as a trailing fin edge 24a. In other IDembodiments trailing edge 22a may extend past, or alternatively may not reach, trailing fin edge 24a. Leading edge 26a of foil 14a preferably, but not necessarily, extends past leading fin edge 28a.

[036] Referring to Fig. 3, a top plan view (frgm the underneath of a surfboard) of an alternate form is illustrated where trailing edge 22a does not extend past trailing fin edge 24a. Foil 14a is also illustrated to be generally comprised of a leading portion 30a and a trailing portion 32a. Leading portion 30a extends beyond leading fin edge 28a whereas trailing portion 32a of foil 14a is co-extensive with at least part of fin 12a.

[037] Referring to Fig. 4 there is illustrated a plan view from the front or nose section of surfboard 10. Leading fin edge 28a of fin 12a is visible. Foil 14a is angled at an angle of 0 to the surface of surfboard 10 to which the foil/fin is attached. Preferably 0 is an acute angle that may be varied depending on the hydrodynamic properties desired to be provided by foil 14a.

[038] Referring to Fig. 5, a perspective view of an exemplary foil 50 is illustrated. Foil should be considered as a stand-alone device or equally as a foil section integrally formed with a fin or fin attachment means. Foil 50 is for use with watercraft, foil including a first surface 51, a second surface 52 (not visible) opposite to first surface 51, a leading portion 53 and a trailing portion 54. First surface 51 and/or second surface 52 may be substantially planar or substantially curved. A variety of contour geometries of first surface 51 or second surface 52 can be provided which could be either substantially convex or substantially concave shapes. A first edge 55 forms part of leading portion 53 of foil 50, first edge 55 is formed between or by first surface 51 and second surface 52. First edge 55 is preferably one dimensional in extent, that is a substantially linear edge, but may 0be substantially two dimensional in extent, for example being a planar or curved surface 0 N between or contiguous with first surface 51 and second surface 52.

l- [039] Foil 50 also includes a lateral edge 56, adjacent first edge 55, with lateral edge 56 forming part of trailing portion 54 of foil 50. Lateral edge 56 is formed between or by first surface 51 and second surface 52. Similarly as described for first edge 55, lateral edge 56 Smay be substantially one dimensional in extent or a two dimensional surface formed Sbetween or contiguous with first surface 51 and second surface 52. As illustrated in Fig. IDit is preferred that lateral edge 56 is two dimensional being substantially planar and formed between first surface 51 and second surface 52. Lateral edge 56 preferably is planar or contoured to abut a corresponding surface of a fin, if foil 50 is a stand-alone device, or alternatively, lateral edge 56 may not be visible but is a conceptual surface in the case of foil 50 being integrally formed with a fin.

[040] Foil 50 also includes second edge 57 opposite first edge 55 and lateral edge 56.

Second edge 57 is formed between or by first surface 51 and second surface 52 and may be substantially one dimensional or two dimensional as previously described for first edge Second edge 57 extends along both leading portion 53 and trailing portion 54.

[041] Lateral edge 56 may be contiguous with first edge 55. For example, first edge may be substantially one dimensional, that is a linear edge, which gradually expands into lateral edge 56 being substantially two dimensional, that is a surface edge. However, as illustrated in Fig. 5, a defined shoulder 58 can be formed between first edge 55 and lateral edge 56. Shoulder 58 is designed to sit near or abut leading fin edge 28a.

[042] Lateral edge 56 would not be provided as a distinctive edge where foil 50 is integrally formed with a fin. In this embodiment, lateral edge 56 can be considered as a joined section between foil 50 and the fin.

[043] In the example embodiment illustrated, and as is further seen in Fig. 6, leading portion 53 tapers to a leading edge 61. The tapering of leading portion 53 may be in one dimension or two dimensions. That is, first edge 55 and second edge 57 may taper towards leading edge 61, and also the thickness of foil 50, defined by first surface 51 and second surface 52, may taper towards leading edge 61.

c1 [044] Likewise, trailing portion 54 may taper towards trailing edge 62 in one dimension or two dimensions. In the embodiment illustrated only the thickness of foil 50, defined by first surface 51 and second surface 52, tapers towards trailing edge 62. The width of foil 50, defined by second edge 57 and lateral edge 56, near trailing portion 54, does not taper, but expands, towards trailing edge 62. However, it should be appreciated that such expansion is optional.

ID[045] Also as illustrated in Fig. 6, first edge 55 may curve towards second surface 52 as part of shoulder 58. However, this particular configuration is optional. First edge 55 may curve to form part of first surface 51 or first edge 55 may become contiguous with lateral edge 56.

[046] In an alternate embodiment, foil 50 may be substantially or slightly twisted or rotated in longitudinal extent, for example about a longitudinal axis. Thus, viewing foil from leading edge 61, a substantial or slight "spiral" configuration along the extent of foil can be provided.

[047] Referring to Fig. 7, there is illustrated a perspective view of fin 70 which includes a fin section 72 integrally formed with a foil section 74. Fin section 72 includes a first fin surface 76, and opposite second fin surface 78, a leading fin edge 80 formed by or between first fin surface 76 and second fin surface 78, and a trailing fin edge 82 formed between or by first fin surface 76 and second fin surface 78. Fin 70 also includes a fin base region 84 near the region where fin 70 attaches to a surfboard or other surf craft. For example, fin may be provided with tabs 86 as attachment means.

[048] Integrated foil section 74 includes a first surface 51 and a second surface 52 (not illustrated). Foil section 74 also includes, as previously described, first edge 55, leading edge 61, second edge 57 and trailing edge 62. In this example, the previously described lateral edge is joined section 56. The plane of foil section 74 extends upwards from the surface of a surfboard to form an angle 0 with the surface of the surfboard.

[049] Referring to Figs. 8(a) to there is illustrated top and side views of additional example configurations of foils, or equally, fins integrated with foils. Figs. 8(a) to 8(f) C illustrate the wide range of configurations that are possible, either for a stand-alone foil or N, a fin integrated with a foil section. Different configurations of foils, or fins integrated with a foil section, will have different performance characteristics and are suited to different types of watercraft or surfboards. For example, the configuration of foil illustrated in Fig.

(-i 8(b) may be better suited to a tri-fin surfboard, whilst the configuration of foil illustrated in Fig. 8(f) may be better suited to a twin-fin surfboard.

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[050] The present invention can find application in all forms of water craft, for example INCsingle-fin, twin-fin or tri-fin surfboards.

[051] The foil is preferably relatively narrow and may be slightly longer than the base of a conventional fin. The foil is preferably fixed at or near the base region of a fin and angles upwards from the surface of a surfboard at an angle 0 towards an opposite outside fin, if more than one fin is used. Use of the foil, or set of foils, seeks to provide increased propulsion. Either or both the longitudinal shape or cross-sectional area can consist of straight lines, angled lines or can be curved. A curved first surface can assist with waterflow over the foil.

[052] A foil could also be provided freestanding on or near an outer rail of a single fin surfboard. That is, the foil could be attached to the underside of the surfboard not being located near a fin. The foil could be attached by, for example, plugs and screws or by a form of adhesive. Foils could also be provided at various locations on the underside of a surfboard regardless of the fin configuration used with the surfboard.

[053] On a surfboard fitted with removable fins, the foil could be attached via existing fin plugs or attached to or integrally formed with the fin itself. This could be achieved in a variety of ways including using fibreglass, an adhesive or a clip-on mechanism. In a preferred form, the foil could be attached to the inside edge of outer removable fins to allow interchange with existing fin systems.

[054] Furthermore, the attachment system used could allow for adjustment, for example in a forward, backward, upward and/or downward direction to enhance performance or to tune the response of the surfboard or fin.

C [055] In use, the foil directs water in the tail region of a surfboard, or other watercraft, to enhance performance. The foil or foils direct water without the "stiffness" or loss of manoeuvrability associated with a larger fin. Preferably the foils are used in pairs that are inwardly angled to effectively direct water which may otherwise exit an outside rail of the surfboard during a turn. A foil can angle at any angle from substantially horizontal to the surface of the surfboard to substantially perpendicular to the surface of the surfboard, and may run longitudinally in parallel to other foils, or alternatively and/or additionally, may run in an end-to-end fashion. Foils may also be positioned or formed at any desired IDlongitudinal angle relative to the direction of a fin or fins of the surfboard.

[056] A foil is preferably made of any low flexibility material, for example including carbon, metal, fibreglass, hardened plastics or any similar material of sufficient rigidity.

[057] Thus, there has been provided a foil and/or a fin integrally formed with a foil.

[058] Optional embodiments of the present invention may also be said to broadly consist in the parts, elements and features referred to or indicated herein, individually or collectively, in any or all combinations of two or more of the parts, elements or features, and wherein specific integers are mentioned herein which have known equivalents in the art to which the invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

[059] Although a preferred embodiment has been described in detail, it should be understood that various changes, substitutions, and alterations can be made by one of ordinary skill in the art without departing from the scope of the present invention.

Claims (19)

1. A foil for use with a watercraft, the foil including: a first surface; a second surface; a first edge forming part of a leading portion of the foil, the first edge formed between or by the first surface and the second surface; IND a lateral edge, adjacent the first edge, and forming part of a trailing portion of the foil, the lateral edge formed between or by the first surface and the second surface; and, a second edge formed opposite the first edge and the lateral edge, the second edge formed between or by the first surface and the second surface.

2. The foil as claimed in claim 1, wherein the leading portion tapers towards the first edge.

3. The foil as claimed in either claim I or 2, wherein the leading portion tapers towards a leading edge.

4. The foil as claimed in any one of the claims I to 3, wherein the trailing portion tapers towards a trailing edge. The foil as claimed in any one of the claims 1 to 3, wherein the trailing portion increases in cross-sectional area towards a trailing edge.

6. The foil as claimed in any one of the claims 1 to 5, wherein the leading portion and the trailing portion taper towards the second edge.

7. The foil as claimed in any one of the claims 1 to 6, wherein the trailing portion increases in cross-sectional area towards the lateral edge.

8. The foil as claimed in any one of the claims 1 to 7, wherein the lateral edge is two dimensional in extent.

9. The foil as claimed in any one of the claims 1 to 8, wherein the lateral edge tapers Ni contiguously into the first edge. Z The foil as claimed in any one of the claims 1 to 8, wherein a shoulder is provided between the first edge and the lateral edge. S11. A foil for use with a watercraft, the foil including: (Ni a leading portion including a first edge, at least part of a second edge opposite the IDfirst edge and a leading edge formed between the first edge and the second edge; and, 10 a trailing portion including a lateral edge adjacent the first edge, at least part of the (,i second edge and a trailing edge formed between the lateral edge and the second edge.

12. The foil as claimed in claim 11, wherein the foil is provided with attachment means to attach the foil to at least one of: the watercraft; and a fin associated with the watercraft.

13. The foil as claimed in claim 11, wherein the foil is provided with attachment means to hold the foil between a fin and the watercraft.

14. The foil as claimed in any one of the claims 11 to 13, wherein the foil is twisted or rotated along a longitudinal axis of the foil. The foil as claimed in any one of the claims 11 to 14, wherein the foil is a stand alone device for post-attachment to a fin or the watercraft.

16. The foil as claimed in claim 11, wherein the foil is integrally formed with a fin.

17. The foil as claimed in claim 11, wherein the foil is integrally formed with a fin attachment means provided on the watercraft.

18. The foil as claimed in any one of the claims 11 to 17, wherein a longitudinal plane of the foil forms an acute angle with a surface of the watercraft to which the foil is attached. 1

19. The foil as claimed in any one of the claims 11 to 18, wherein two foils are I associated with a single fin, each foil extending from opposing fin surfaces near a fin base Zregion. ,l

20. A fin for use with a watercraft, the fin including: a fin section formed by a first fin surface and an opposite second fin surface, the first fin surface and the second fin surface forming a leading fin edge and a trailing fin edge, the fin section also including a fin base region near where the fin attaches to the O watercraft; and, a foil section integrally formed with the fin section near the fin base region, the foil section protruding laterally from the first fin surface at an acute angle to the surface of the watercraft near the fin base region.

21. The fin as claimed in claim 20, where the foil section includes a first surface, a second surface, a first edge forming part of a leading portion of the foil, the first edge formed between or by the first surface and the second surface, a joined section attached to or forming part of the fin base region, the joined section adjacent the first edge and forming part of a trailing portion of the foil, the joined section formed between the first surface and the second surface, a second edge formed opposite the first edge and the joined section, the second edge formed between or by the first surface and the second surface.

22. A foil, substantially as hereinbefore described with reference to and as illustrated in the accompanying figures.

23. A fin, substantially as hereinbefore described with reference to and as illustrated in the accompanying figures. DATED this 27 th day of July 2006 ROGER DOUGLAS HAMILTON By His Patent Attorneys DAVIES COLLISON CAVE