Hydrofoil mast, kit and watercraft

Abstract

A hydrofoil mast is for a watercraft. The mast has an elongate body extending between a first end of the mast configured to be connected to an underside of the watercraft and a second end of the mast configured to be connected to a hydrofoil system. The first and second ends are similar, allowing the mast to be inverted and assembled with the watercraft with the first end connected to the hydrofoil system and the second end connected to the underside of the watercraft. A motor mount is configured to support an electric motor to drive a propulsion device. The body of the mast defines one or more internal conduits configured to accommodate one or more cables to connect the motor to a power source and controller on the watercraft. These conduits extend from the motor mount to the first end and to the second end.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is the U.S. national stage application of International Application No. PCT / AU2024 / 050024, filed Jan. 17, 2024, which international application was published on Jul. 25, 2024, as International Publication WO 2024 / 152084 in the English language. The International Application claims priority of Australian Patent Application No. 2023900095, filed Jan. 17, 2023. The international application and Australian application are both incorporated herein by reference, in entirety.TECHNICAL FIELD

[0002] Embodiments relate to hydrofoil masts for watercraft. Some embodiments relate to associated hydrofoil kits and watercraft, such as surfboards, kite-surfing boards, foil boards, and e-foil boards (electric hydrofoil boards), for example.BACKGROUND

[0003] Hydrofoils are increasingly employed to provide lift to watercraft such as surfboards and kite-surfing boards, for example. Typically, a hydrofoil for a watercraft comprises primary and secondary foils mounted on a mast extending downward from a hull of the watercraft. Often the primary and secondary foils are arranged on a fuselage in a similar configuration to aircraft.

[0004] Some watercraft combine hydrofoils with propulsion, such as e-foils, for example, which make use of electric motors to drive propellers. Often the propulsion device is mounted on the fuselage of the hydrofoil itself, or to the mast near the hydrofoil.

[0005] It is desired to address or ameliorate one or more shortcomings or disadvantages associated with existing hydrofoil masts and associated kits and watercraft, or to at least provide a useful alternative.

[0006] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims.

[0007] Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.SUMMARY

[0008] Some embodiments relate to a hydrofoil mast for a watercraft, the mast comprising: an elongate body extending between a first end of the mast, configured to be connected to an underside of a watercraft, and a second end of the mast, configured to be connected to a hydrofoil system; and a motor mount configured to support an electric motor to drive a propulsion device; wherein the first end and second end of the mast are similar, allowing the mast to be inverted and assembled with the watercraft with the first end connected to the hydrofoil system and the second end connected to the underside of the watercraft.

[0009] In some embodiments, the motor mount is integrally formed with the body.

[0010] In some embodiments, the motor mount and body are formed together as a unitary structure of composite material.

[0011] In some embodiments, the body further defines one or more internal conduits extending from the motor mount to the first end and configured to accommodate one or more cables to connect the motor to a power source and controller on the watercraft.

[0012] In some embodiments, the one or more internal conduits extend from the motor mount to the second end as well as the first end of the mast.

[0013] In some embodiments, one or more cables are located in the internal conduits and extend from the motor mount to the first end and the second end of the mast.

[0014] In some embodiments, the motor mount is located closer to the first end than the second end of the mast.

[0015] In some embodiments, a distance between a centreline of the motor mount and the first end of the mast is in the range of 5% to 40% of the length of the mast, 10% to 35% of the length of the mast, 15% to 30% of the length of the mast, 20% to 25% of the length of the mast, or less than 40% of the length of the mast, less than 25% of the length of the mast, less than 20% of the length of the mast, less than 10% of the length of the mast, or about 10% of the length of the mast, about 15% of the length of the mast about 20% of the length of the mast, or about 25% of the length of the mast, for example.

[0016] In some embodiments, the motor mount defines a threaded portion configured to connect to part of a propulsion device configured to be driven by the motor.

[0017] In some embodiments, part of the motor mount protrudes from a trailing edge of the body.

[0018] Some embodiments relate to a hydrofoil mast kit comprising: a mast according to any one of the described embodiments; and a mast mount configured to connect the first or second end of the mast to the underside of a watercraft.

[0019] In some embodiments, the mast mount is configured to connect the first or second end of the mast to the underside of the watercraft with a standoff distance between the mast and the underside of the watercraft.

[0020] In some embodiments, the standoff distance is at least 40 mm or at least 50 mm, for example.

[0021] In some embodiments, the mast mount is configured to be connected to a standard hydrofoil mounting system.

[0022] In some embodiments, the kit may further comprise an electric motor configured to be accommodated in the motor mount.

[0023] In some embodiments, the kit may further comprise a propulsion device, configured to connect to the motor and motor mount.

[0024] In some embodiments, the propulsion device comprises a jet thruster or ducted propeller.

[0025] In some embodiments, the kit may further comprise a hydrofoil system.

[0026] In some embodiments, the hydrofoil system comprises: a fuselage configured to be connected to the first or second end of the mast; a primary hydrofoil connected to the fuselage; and a secondary hydrofoil connected to the fuselage.

[0027] Some embodiments relate to a watercraft comprising a mast according to any one of the described embodiments.BRIEF DESCRIPTION OF DRAWINGS

[0028] Embodiments will now be described, for exemplary purposes only, in relation to drawings, in which:

[0029] FIG. 1A is an isometric view of a hydrofoil mast, according to some embodiments;

[0030] FIG. 1B is an isometric view of the mast of FIG. 1A showing internal features;

[0031] FIG. 2A is an isometric view of a hydrofoil mast with a propulsion device, according to some embodiments;

[0032] FIG. 2B is an isometric view of the mast and propulsion device of FIG. 2A showing internal features;

[0033] FIG. 3A is an isometric view of a mast mount, according to some embodiments;

[0034] FIG. 3B is an isometric view of the mast mount of FIG. 3A showing internal features;

[0035] FIG. 4A is an isometric view of a hydrofoil assembly, according to some embodiments;

[0036] FIG. 4B is a plan view of the hydrofoil assembly of FIG. 4A;

[0037] FIG. 4C is a rear view of the hydrofoil assembly of FIG. 4A;

[0038] FIG. 4D is an isometric view of the hydrofoil assembly of FIG. 4A in an alternative configuration;

[0039] FIG. 5A is a bottom isometric view of a watercraft comprising a hydrofoil assembly, according to some embodiments; and

[0040] FIG. 5B is a bottom isometric of the watercraft of FIG. 5A showing the hydrofoil assembly in an alternative configuration.DETAILED DESCRIPTION

[0041] 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.

[0042] In the figures, incorporated to illustrate features of an example embodiment, like reference numerals are used to identify like parts throughout the figures.

[0043] Hydrofoil watercraft with propulsion systems typically position the propulsion system so that the thrust is produced at or near the hydrofoil. This is beneficial for balancing pitching moments associated with the thrust of the propulsion system and the drag of the hydrofoil system. It is also beneficial when the hydrofoil lifts the hull of the watercraft above the surface of the water, as the propulsion system remains submerged with the hydrofoil system.

[0044] However, when the propulsion system is not providing thrust (e.g., if the watercraft is to be used without propulsion) the propulsion system adds drag to the watercraft, and being further away from the hull increases the pitching moment due to the drag.

[0045] Watercraft designs with hydrofoil systems but without propulsion systems-such as foilboards for surfing, kite-surfing or paddleboarding-typically aim to reduce drag resistance and rely on wind, wave or human power for propulsion.

[0046] Positioning a propulsion system on a watercraft (e.g., a foilboard) with the thrust produced near the hull (or board) allows for a user to operate the propulsion system to produce thrust and accelerate until the hydrofoil system lifts the board above the surface of the water, and then the propulsion system can be switched off and the user can rely on wave, wind or human power to maintain velocity and lift. For example, human power may include paddling or pumping the foilboard by repeatedly pushing down on the board to increase velocity and bouncing up to allow the lift generated by the hydrofoil to raise the board.

[0047] When the propulsion system is not in use, it is contributing to drag, so it is beneficial to position the propulsion system near the hull (or board) so that it can be raised above the water surface along with the board when the velocity and lift is sufficient, and therefore reduce or eliminate the drag contribution from the propulsion system.

[0048] The inventor of the present disclosure has realised that being able to adjust the position or depth of the propulsion system to be nearer the hydrofoil system or nearer the hull / board, allows a user to change between a first configuration better suited to ongoing use of the propulsion system, and a second configuration better suited to intermittent use of the propulsion system and raising the propulsion system above the water surface when relying on wave, wind or human power for propulsion.

[0049] The embodiments described herein allow for such adjustments of the propulsion system position and overall configuration of a watercraft.

[0050] Referring to FIGS. 1A and 1B a hydrofoil mast 100 for a watercraft is shown according to some embodiments. The mast 100 comprises an elongate body 110 extending between a first end 111 and a second end 112.

[0051] The first end 111 of the mast 100 is configured to be connected to an underside of a watercraft, and the second end 112 of the mast 100 is configured to be connected to a hydrofoil system. However, the first and second ends 111, 112 are similar, allowing the mast 100 to be inverted and installed with the second end 112 connected to the underside of a watercraft and the first end 111 connected to a hydrofoil system.

[0052] The mast 100 also comprises a motor mount 120 configured to support an electric motor to drive a propulsion device. For example, a 40 mm or 56 mm 500 kv in runner motor, or any other suitable motor may be used.

[0053] The motor mount 120 may define a recess configured to receive a motor and secure it relative to the body 110.

[0054] The motor mount 120 may comprise a bracket or other structure to support the motor which may be connected to the mount 120 with mechanical fasteners. Alternatively, or additionally, the motor mount 120 may comprise a keyed portion configured to engage a complimentary keyed portion of a motor.

[0055] The motor may be secured in the motor mount 120 by a cap 131 which may fully or partially enclose the motor within the motor mount 120. For example, the cap 131 may form part of a propulsion device 130, as shown in FIGS. 2A and 2B. Alternatively, the cap 131 may be separate from the propulsion device 130.

[0056] The motor mount 120 may define a threaded portion configured to connect to part of a propulsion device configured to be driven by the motor. For example, the threaded portion may be configured to engage the cap 131.

[0057] The motor mount 120 may be integrally formed with the body 110. For example, the motor mount 120 and body 110 may be formed together as a unitary structure of composite material, such as carbon fibre or fibreglass material, for example.

[0058] Forming the motor mount 120 integrally with the body 110 allows for a more streamlined design, which can assist in reducing drag on the motor mount 120.

[0059] The body 110 may define a generally constant cross-sectional profile, which may also be streamlined. The cross-sectional profile of the body 110 may correspond to a symmetric NACA series foil profile, for example. Some embodiments of the body 110 may have a cross-sectional profile corresponding to a NACA 64-0011 foil profile. Some embodiments of the body 110 may have a cross-sectional profile corresponding to a NACA 64-0017 foil profile.

[0060] A central axis or centreline 121 of the motor mount 120 may extend substantially perpendicularly away from the trailing edge of the body 110. The centreline 121 of the motor mount 120 may be aligned with a chord line of the cross-sectional profile of the body 110 extending from the leading edge 101 to the trailing edge 102, for example.

[0061] The motor mount 120 may be partially embedded in the trailing edge 102 of the body 110. The motor mount 120 may be configured to support the motor in a position with a longitudinal axis of the trailing edge 102 intersecting the motor.

[0062] An external surface of the motor mount 120 may smoothly transition into the body 110. For example, the motor mount 120 may define a filleted transition to the surface of the body 110.

[0063] The motor mount 120 may be formed to flare out from the surface of the body 110 part way between the leading edge 101 and trailing edge 102 and define a substantially cylindrical section at or near the trailing edge 102. The cylindrical section of the motor mount 120 may extend aftwards from the trailing edge 102 with a substantially cylindrical profile.

[0064] The body 110 further defines one or more internal conduits 122 extending from the motor mount 120 to the first end 111 of the mast 100. The conduits 122 are configured to accommodate one or more cables to connect the motor (in the motor mount 120) to a power source and controller on the watercraft.

[0065] As shown in FIG. 1B, in some embodiments, the one or more internal conduits 122 extend from the motor mount 120 to the second end 112 as well as the first end 111 of the mast 100. This allows for the mast 100 to be installed with either the first end 111 or the second end 112 of the mast 100 connected to the watercraft with cables connecting the motor to the power source and controller on the watercraft.

[0066] The motor mount 120 is located closer to one end of the mast 100 than the other. In the drawings, motor mount 120 is shown nearer the second end 112 than the first end 111. However, the first and second ends 111, 112 are interchangeable, and the mast 100 could equally be described as having the motor mount 120 positioned closer to the first end 111 than the second end 112 of the mast 100.

[0067] FIGS. 2A and 2B show the hydrofoil mast 100 with a propulsion device 130 connected to the motor mount 120. The propulsion device 130 may comprise a jet thruster or ducted propeller comprising a propeller or impeller 133 coupled to a motor (not shown) secured in the motor mount 120, and a duct or shroud 134 surrounding the impeller 133.

[0068] The propulsion device 130 may also comprise the cap 131, or in some embodiments, the cap 131 may be separate, as discussed above.

[0069] The shroud 134 defines an inlet 135 fore of the impeller 133 and an outlet 137 aft of the impeller 133. The shroud 134 may enhance safety for people and animals in the water near the propulsion device 130 during operation compared with an open propeller.

[0070] In some embodiments, the propulsion device may comprise an open propeller without a shroud. In yet other embodiments, the open propeller may be foldable to reduce drag in the event it is not being operated but still under water.

[0071] Referring to FIGS. 3A and 3B, a mast mount 300 is shown according to some embodiments. The mast mount 300 is configured to mount the mast 100 to a watercraft, such as a foil board. Any suitable mount system may be used, and there are a number of standard mount systems already in use, such as 2 conventional 10 inch fin boxes previously used for surfboard fins, or longer 14-16 inch tracks configured to receive mechanical fasteners to secure the mast mount 300 to the underside of a watercraft (e.g., foilboard). The watercraft may include tracks in the underside allowing the fore-aft position of the mast mount 300 to be adjusted relative to the watercraft.

[0072] The mast mount 300 may comprise a fixing plate 305 configured to be fastened to the underside of a watercraft, and a mast socket 310 protruding away from the fixing plate 305. The mast socket 310 is configured to receive the first or second end 111, 112 of the mast 100, which may be secured in the socket 310 by clamping screws or other mechanical fasteners, for example. In some embodiments, a chamfered or tapered fitting is used to secure the mast 100 in the socket 310. The chamfered or tapered fitting may be used together with mechanical fasteners such as bolts to provide a rigid connection between the mast 100 and the mast socket 310. A rigid connection between the mast 100 and the mast socket 310 may provide the user / rider with more “feel” of the thrust generated by the propulsion device 130 on the mast 100, allowing better control of the watercraft.

[0073] The mast mount 300 may also define a stand-off portion 320 disposed between the fixing plate 305 and the socket 310 defining a stand-off distance 322 between the mast 100 and watercraft, as illustrated in FIG. 3B.

[0074] When the mast 100 is configured with the motor mount 120 nearer the hydrofoil system (as shown in FIG. 4A), it may be advantageous for the motor mount 120 to be located as near as practicable to one end of the mast 100 so that the propulsion device 130 is positioned close to the hydrofoil system. However, when the mast is configured with the motor mount 120 nearer the watercraft, it may be advantageous to provide a stand-off from the watercraft to reduce turbulent interference between the propulsion device and the boundary layer in the water adjacent to the underside of the watercraft.

[0075] The optimal stand-off distance will depend on the dimensions and characteristics of the propulsion device to be used.

[0076] The stand-off portion 320 may have a depth defining a stand-off distance 322 in the range of 100 mm to 300 mm, 150 mm to 250 mm, 200 mm to 250 mm, or about 220 mm, for example.

[0077] A depth of the socket 310 (corresponding to a length of the mast 100 to be accommodated in the socket 310), may be in the range of 30 mm to 100 mm, 40 mm to 60 mm, or about 50 mm, for example.

[0078] The mast mount 300 may also define a recess 350 in the fixing plate 305 (and / or stand-off portion 320) to accommodate connectors or part of an electronic speed controller, for example, to connect the power source and controller to the motor via cables in the conduits 122 of the mast 100.

[0079] The distance from the motor mount 120 to the nearest end (111 or 112) of the mast may also be varied in different embodiments depending on the application and the diameter and characteristics of the propulsion device to be used with the mast 100.

[0080] FIGS. 4A to 4C illustrate a hydrofoil assembly 400 in a first configuration comprising the mast 100, propulsion device 130, mast mount 300 connected to the first end 111 of the mast 100 and a hydrofoil or hydrofoil system 410 connected to the second end 112 of the mast 100, with the motor mount 120 and propulsion device 130 nearer the hydrofoil 410.

[0081] FIG. 4D illustrates a second configuration of the assembly 400 with the mast 100 inverted relative to the first configuration such that the mast mount 300 is connected to the second end 112 of the mast 100 and a hydrofoil system or hydrofoil 410 connected to the first end 111 of the mast 100, with the motor mount 120 and propulsion device 130 nearer the mast mount 300.

[0082] The hydrofoil 410 comprises a fuselage 412 which is connected to the mast 100, and primary and secondary foils 414, 415 connected to the fuselage 412. Here, the primary foil 414 acts like a front wing fore of the smaller secondary foil 415 which acts as a stabiliser, similar to a conventional aeroplane. The hydrofoil 410 may comprise other foil configurations, such as split wing or canard, for example.

[0083] The position of the motor mount 120 relative to the hydrofoil 410 is represented in FIG. 4C by dimension lines, illustrating a distance 420 between the centreline 121 of the motor mount 120 and the second end 112 of the mast 100, which may be in the range of 5% to 40% of the length of the mast, 10% to 35% of the length of the mast, 15% to 30% of the length of the mast, 20% to 25% of the length of the mast, or less than 40% of the length of the mast, less than 25% of the length of the mast, less than 20% of the length of the mast, less than 10% of the length of the mast, or about 10% of the length of the mast, about 15% of the length of the mast, about 20% of the length of the mast, or about 25% of the length of the mast, for example.

[0084] In some embodiments, the distance 420 between the centreline 121 of the motor mount 120 and the second end 112 of the mast 100 may be in the range of 50 mm to 250 mm, 50 mm to 150 mm, 60 mm to 100 mm, about 60 mm, about 70 mm, about 80 mm, about 100 mm, about 150 mm, or about 200 mm, for example.

[0085] The hydrofoil mast 100 may be provided as part of a kit comprising a mast and a mast mount 300 configured to connect the first or second end of the mast to the underside of a watercraft. In some embodiments, the kit further comprises an adapter configured to allow fuselages from different brands to be connected to the mast. The adapter may be configured to connect to the first end 111 of the mast 100. The adapter may alternatively or additionally be configured to connect to the second end 112 of the mast 100. The adapter may comprise a socket to connect to the first end 111 and / or the second end 112, and a bolted connection configured to connect to the fuselage.

[0086] The kit may further comprise an electric motor configured to be accommodated in the motor mount. The kit may also comprise a propulsion device, configured to connect to the motor and motor mount.

[0087] The kit may further comprise a hydrofoil system 410. The kit may be assembled to form a hydrofoil assembly 400, as shown in FIGS. 4A to 4D.

[0088] The hydrofoil assembly 400 may then be mounted on the hull 501 (or board) of a watercraft 500 by the mast mount 300 as shown in FIGS. 5A and 5B.

[0089] As discussed above, the hydrofoil assembly 400 may be mounted to the hull 501 in a first configuration with the motor mount 120 positioned nearer the hydrofoil 410 than the hull 501 of the watercraft 500, as shown in FIG. 5A.

[0090] Alternatively, the hydrofoil assembly 400 may be mounted to the hull 501 in a second configuration with the motor mount 120 positioned nearer the hull 501 than the hydrofoil 410, as shown in FIG. 5B.

[0091] It will be appreciated by persons skilled in the art that numerous variations and / or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

[0092] In the foregoing description of preferred embodiments, specific terminology has been resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as “front” and “rear”, “inner” and “outer”, “above” and “below” and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.

Claims

1. A hydrofoil mast for a watercraft, the mast comprising:an elongate body extending between a first end of the mast, configured to be connected to an underside of a watercraft, and a second end of the mast, configured to be connected to a hydrofoil system; anda motor mount configured to support an electric motor to drive a propulsion device;wherein the first end and second end of the mast are similar, allowing the mast to be inverted and assembled with the watercraft with the first end connected to the hydrofoil system and the second end connected to the underside of the watercraft.

2. The mast of claim 1, wherein the motor mount is integrally formed with the body.

3. The mast of claim 2, wherein the motor mount and body are formed together as a unitary structure formed of composite material.

4. The mast of claim 1, wherein the body further defines one or more internal conduits extending from the motor mount to the first end and configured to accommodate one or more cables to connect the motor to a power source and controller on the watercraft.

5. The mast of claim 4, wherein the one or more internal conduits extend from the motor mount to the second end as well as the first end of the mast.

6. The mast of claim 5, wherein one or more cables are located in the internal conduits and extend from the motor mount to the first end and the second end of the mast.

7. The mast of claim 1, wherein the motor mount is located closer to the first end than the second end of the mast.

8. The mast of claim 7, wherein a distance between a centerline of the motor mount and the first end of the mast is in the range of 5% to 40% of the length of the mast.

9. The mast of claim 1, wherein the motor mount defines a threaded portion configured to connect to part of a propulsion device configured to be driven by the motor.

10. The mast of claim 1, wherein part of the motor mount protrudes from a trailing edge of the body.

11. A hydrofoil mast kit comprising:a mast according to claim 1, anda mast mount configured to connect the first or second end of the mast to the underside of a watercraft.

12. The kit of claim 11, wherein the mast mount is configured to connect the first or second end of the mast to the underside of the watercraft with a standoff distance between the mast and the underside of the watercraft.

13. The kit of claim 12, wherein the standoff distance is at least 40 mm.

14. The kit of claim 13, wherein the mast mount is configured to be connected to a standard hydrofoil mounting system.

15. The kit of claim 11, further comprising an electric motor configured to be accommodated in the motor mount.

16. The kit of claim 15, further comprising a propulsion device, configured to connect to the motor and the motor mount.

17. The kit of claim 16, wherein the propulsion device comprises a ducted propeller.

18. The kit of claim 11, further comprising a hydrofoil system.

19. The kit of claim 18, wherein the hydrofoil system comprises:a fuselage configured to be connected to the first or second end of the mast;a primary hydrofoil connected to the fuselage; anda secondary hydrofoil connected to the fuselage.

20. (canceled)

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