UNDERWATER WING FOR A WATERCRAFT

Abstract

An underwater wing for a water sports apparatus, having an outer shaped body forming the profile of the wing and consisting of a material of a first type with a first hardness, and including at least one mast receiving portion arranged in the underwater wing. The underwater wing additionally includes a supporting structure consisting of at least one material of a second type with a second hardness, and the shaped body is molded onto the supporting structure and completely encloses the supporting structure, the second hardness being greater than the first hardness.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a national phase application of PCT Application No. PCT/IB2022/052148, filed Mar. 10, 2022, entitled “UNDERWATER WING FOR A WATERCRAFT”, which claims the benefit of Austrian Patent Application No. A 96/2021, filed May 14, 2021, each of which is incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present application relates to a hydrofoil for a watercraft, in particular a water sports device, with an outer body forming the profile of the foil and made of at least one material of a first type with a first hardness and with at least one mast mount arranged in the hydrofoil, as well as a method for its manufacture.

2. Description of the Related Art

Hydrofoils are becoming increasingly popular in the water sports sector, both for use in kitesurfing and for use with windsurfing with windsurfing boards or kitesurfing boards specially designed for the respective purpose. The purpose and the great advantage of the hydrofoil in these new sports known as foiling is that the hydrofoil, due to its profile, is able to lift the surfboard and the surfer standing on it out of the water from a certain speed of the surfboard, on which the hydrofoil is mounted with a mast projecting into the depth of the water, resulting in a dramatic drop in the resistance of the corresponding water sports equipment, as with hydrofoil boats and ships. For this reason, hydrofoils enable wind-powered watercraft to travel at astonishingly high speeds even in the lightest of winds. This gives the mast, which acts as the fin of the surfboard, strong guidance in the water, making it possible to ride effectively upwind and thus maintain or gain height upwind.

The sport of kitesurfing in particular is enjoying increasing popularity due to an initially rather flat learning curve compared to windsurfing. For this reason, even inexperienced water sports enthusiasts are increasingly able to use hydrofoils. Even though the sport is relatively easy to learn, kitesurfing also involves a number of risks that are often underestimated by amateurs. Due to the high demands on bending and torsional rigidity and the resulting high strength of the materials used, the risk of an athlete sustaining blunt injuries to the hydrofoils that protrude from the kiteboards or surfboards due to the mast is not negligible in the event of improper handling and especially in the event of a fall. Cuts and puncture injuries are also common, which an athlete or bystander can sustain on the thin and sharp tips and edges of the hydrofoil thar are existing for fluidic reasons.

As already mentioned, hydrofoils have to meet high mechanical requirements and are therefore by no means cheap to purchase. Highly developed materials and high-quality plug and screw connections as well as complex manufacturing processes lead to high costs, so that damage to the hydrofoil due to improper handling can be a significant cost factor, especially in the cost planning of a rental company, if hydrofoils are to be rented out. In addition, the rental business tends to be dominated by athletes who only exercise the sport sporadically and therefore generally have little experience. In this area in particular, it therefore makes sense to protect both athletes and equipment.

SUMMARY OF THE INVENTION

The present invention is therefore based on the task of designing a hydrofoil in such a way that, on the one hand, the risk of injury to the athlete and the risk of damage to the hydrofoil are reduced, while the hydrodynamic performance of the hydrofoil should remain largely unaffected.

To solve this problem, the present invention is based on a hydrofoil of the type mentioned above and further including a support structure made of at least one material of a second type with a second hardness. The outer body is molded onto the support structure and completely surrounds the support structure, and the second hardness is greater than the first hardness. This means that the hydrofoil is made of a relatively soft material on the outside, which means that injuries to the athlete as well as fractures and splintering of the hydrofoil, for example due to it resting on a rocky beach, can be largely avoided. However, since the material of the first type has a relatively low hardness, it is not suitable for absorbing the extremely high hydrodynamic forces so that the hydrofoil would be warping. This is always associated with an enormous loss of performance of the hydrofoil and must therefore be compensated for by providing the support structure made of at least a second type of material with a second hardness, which is, however, completely embedded into the first type of material. As the outer body is molded onto the support structure, the forces acting on the body and thus on the hydrofoil are transferred to the support structure, so that excessive deformation of the soft outer body can be largely avoided. This creates an injury-proof and damage-resistant hydrofoil that still has very good hydrodynamic performance.

In order to enable the hydrofoil to be attached to a water sports device, it comprises a mast mount according to the invention. To attach the mast to the hydrofoil according to the invention, the mast mount is located on the upper side (suction side) of the foil, so that the foil comes to rest more or less horizontally in the water during use in order to generate corresponding buoyancy.

The choice of material of the first type is of great importance both for the bending and torsional rigidity of the outer body and thus for the hydrodynamic behavior as well as for its relative flexibility to avoid injury on the one hand and chipping on the other. The present invention is therefore preferably further embodied in that the at least one material of the first type is selected from one or more of the group consisting of elastomers for injection molding, polyurethane materials, silicone materials, ethylene-propylene-diene rubber, and acrylonitrile-butadiene rubber. These materials can be easily shaped and, if necessary, reworked using methods known in the state of the art and offer a good compromise between strength for hydrodynamic behavior and flexibility to prevent injuries.

Preferably, the at least one material of the first type has a Shore A hardness of 40 to 90, preferably 60 to 80, particularly preferably 65-75. The harder the material is, for example with a hardness of Shore A 90, the better the hydrodynamic behavior. The softer the material, for example with a hardness of Shore A 40, the better the protection against injury and also the tendency to damage the hydrofoil. In the context of the present invention, a Shore A hardness of preferably 65-75 has proven to be a useful compromise between these two conflicting requirements.

In order to achieve a good hydrodynamic performance of the hydrofoil according to the invention while still providing very good protection against injury even with the relatively soft outer body, the outer body can comprise different areas made of different materials of the first type, as corresponds to a preferred embodiment of the present invention. Thus, regions of the hydrofoil according to the invention can be made of a material of the first type, for example with a Shore A hardness of, for example, 90, in certain non-edge areas in order to ensure increased strength against bending and torsion in the outer body itself.

The material of the second type for the support structure, on the other hand, must have the best possible mechanical properties with the lowest possible weight in order to compensate for the tendency of the soft outer body to deform. In this context, the present invention is preferably further embodied in that the material of the second type is selected from the group consisting of fiber-reinforced, in particular glass fiber-reinforced plastics, carbon fiber-reinforced plastics, steel, stainless steel and aluminum. These materials have a significantly greater hardness than the materials of the first type and can absorb the loads that occur.

In the present invention, particular attention is paid to making the edges and corners of the hydrofoil according to the invention soft and yielding. However, this in turn means a compromise, as the edges are thin and therefore susceptible to deformation, but at the same time are of great importance for hydrodynamic performance. For this reason, for example, the foil tips are usually shaped into winglets to deflect unfavorable water turbulence. However, in order to nevertheless achieve sufficient stability, the invention is preferably further developed in such a way that the support structure extends over a range of at least 60%, at least preferably 70%, further preferably at least 80%, in particular preferably at least 90% of the span of the hydrofoil.

In principle, it may be sufficient and intended that the support structure is freely accommodated in the outer body. However, it is generally provided that at least a part of the support structure is connected to the at least one mast mount, as corresponds to a preferred embodiment of the present invention. In this way, the support structure in turn rests on the at least one mast mount and subsequently on the mast, which counteracts the deformation of the outer body.

Preferably, the support structure consists of a plurality of rods, plates and/or rings. A support structure according to the present invention can be constructed from these elements, whereby, according to a further preferred embodiment of the present invention, rods, plates, and rings can be connected to one another independently of the outer body. The connection can be made by screwing, welding, soldering or similar. The rods, plates and/or rings can be flattened if necessary. Rings can also be formed into elliptical or flattened shapes compared to the ring shape.

An alternative and preferred embodiment of the present invention provides for the support structure to be milled in one piece from the material of the second type. The support structure is milled from an aluminum block using a CNC milling machine, for example.

In order to ensure a durable connection between the outer body and the support structure, the present invention can preferably be further developed in such a way that the support structure is at least partially coated with an adhesion-promoting layer.

In the context of the present invention, the provision of a relatively soft outer body opens the possibility of equipping the hydrofoil with active, possibly digitally automated control functions. According to a preferred embodiment of the present invention, the hydrofoil according to the invention can therefore be further designed in such a way that the support structure is supplemented by a plurality of movable guide elements, which are preferably movable by linkage elements penetrating the outer body or by hydraulic elements arranged in the outer body. The guide elements are made of a material of the second type and are therefore have a high stability. When the guide elements are deflected accordingly, the outer body is also deflected, which controls the buoyancy properties of the hydrofoil.

The method according to the invention comprises at least the following steps:

• • providing a support structure made of at least one material of a second type with a second hardness, and arranging at least one mast mount in the region of the support structure,
  • molding an outer body from at least one material of a first type with a first hardness.

Preferably, molding is performed by casting the material of the first type into a mold containing the support structure with a material of the first type selected from one or more of the group consisting of elastomers for injection molding, polyurethane materials, silicone materials, ethylene-propylene-diene rubber and acrylonitrile-butadiene rubber, wherein preferably different portions of the outer body are casted from different materials of the first type.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in more detail below with reference to an embodiment shown in the drawing.

FIG. 1 shows a perspective view of a hydrofoil according to the invention,

FIG. 2 shows a support structure according to a first embodiment of the present invention,

FIG. 3 shows a support structure according to a second embodiment according to the invention,

FIG. 4 shows a view of the hydrofoil according to the invention partially in section and

FIG. 5 shows a support structure supplemented with guide elements.

DETAILED DESCRIPTION

In FIG. 1, a hydrofoil according to the invention is designated by the reference sign 1. The hydrofoil 1 has a leading edge 2 and a trailing edge 3 and can be connected to a flow-optimized mast not shown in the figures by means of a mast mount 4 on the upper side (suction side) of the wing or foil. FIG. 1 also shows, in particular, the outer body 5 forming the profile of the hydrofoil, which forms the main body and the surface of the hydrofoil. The foil tips are marked with the reference sign 6.

A support structure 7 is shown in perspective view in FIG. 2. In this embodiment, the plurality of rods 8, plates 9 and rings 10 of the support structure 7 are connected to the mast mount 4 arranged centrally in the support structure 7. The support structure is also connected to the mast mount 4. However, it is also conceivable that the support structure is not connected to the mast mount 4 and lies freely in the outer body 5. It is also conceivable that a plurality of mast mounts, preferably two mast mounts, are provided.

FIG. 3 shows a support structure 7 that is milled in one piece from the material of the second type. The support structure 7 has recesses 11 for a better connection with the outer body.

FIG. 4 shows that the outer body 5 is molded onto the support structure 7, whereby hydrodynamic forces are transferred from the outer body 5 to the support structure 7 and absorbed by it.

In FIG. 5, the support structure 7 is supplemented by guide elements 12, which can be moved by corresponding linkage elements 13. An outer body 5 is thus also deformed in this area, which can influence the buoyancy properties of the hydrofoil according to the invention. This enables active control of the hydrofoil.

Claims

1-16. (canceled)

17. A hydrofoil for a water sports device comprising:

an outer body forming a profile of the hydrofoil and comprising at least one first material of a first type having a first hardness;

at least one mast mount arranged in the hydrofoil; and

a support structure made of at least one second material of a second type with a second hardness;

wherein the outer body is molded onto the support structure and completely surrounds the support structure; and

wherein the second hardness is greater than the first hardness.

18. The hydrofoil according to claim 17, wherein the at least one first material of the first type is selected from one or more of the group consisting of elastomers for injection molding, polyurethane materials, silicone materials, ethylene-propylene-diene rubber, and acrylonitrile-butadiene rubber.

19. The hydrofoil according to claim 17, wherein the at least one first material of the first type has a Shore A hardness of 40-90.

20. The hydrofoil according to claim 19, wherein the at least one first material of the first type has a Shore A hardness of 60-80.

21. The hydrofoil according to claim 20, wherein the at least one first material of the first type has a Shore A hardness of 65-75.

22. The hydrofoil according to claim 17, wherein the outer body comprises different regions made of different materials of the first type.

23. The hydrofoil according to claim 17, wherein the at least one second material of the second type is selected from the group consisting of fiber-reinforced plastics, glass fiber-reinforced plastics, carbon fiber-reinforced plastics, steel, stainless steel, and aluminum.

24. The hydrofoil according to claim 17, wherein the support structure extends over a range of at least 60% of a span of the hydrofoil.

25. The hydrofoil according to claim 17, wherein at least a part of the support structure is connected to the at least one mast mount.

26. The hydrofoil according to claim 17, wherein the support structure consists of at least one of a plurality of rods, a plurality of plates, and a plurality of rings.

27. The hydrofoil according to claim 26, wherein at least two of the plurality of rods, the plurality of plates, and the plurality of rings are connected to each other independently of the outer body.

28. The hydrofoil according to claim 17, wherein the support structure is milled in one piece from the material of the second type.

29. The hydrofoil according to claim 17, wherein the support structure is at least partially coated with an adhesion-promoting layer.

30. The hydrofoil according to claim 17, wherein the support structure is supplemented by a plurality of movable guide elements.

31. The hydrofoil according to claim 30, wherein the guide elements are movable by linkage elements penetrating the outer body or by hydraulic elements arranged in the outer body.

32. A method of manufacturing the hydrofoil according to claim 17, comprising at least the following steps:

providing a support structure made of at least one material of a second type with a second hardness;

arranging at least one mast mount in a region of the support structure,

molding an outer body from at least one material of a first type with a first hardness.

33. The method according to claim 32, wherein the molding is carried out by casting the at least one first material of the first type into a mold containing the support structure, the at least one material of the first type being selected from one or more of the group consisting of elastomers for injection molding, polyurethane materials, silicone materials, ethylene-propylene-diene rubber, and acrylonitrile-butadiene rubber.

34. The method according to claim 32, wherein different regions of the outer body are cast from different materials of the first type.