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Title:
BIDIRECTIONAL HYDROFOIL
Document Type and Number:
WIPO Patent Application WO/2019/050811
Kind Code:
A1
Abstract:
A watercraft having a hull and two opposed intended axes of travel is disclosed. The watercraft has two hydrofoils mounted on its hull which are symmetric across a plane perpendicular to the intended axes of travel of the watercraft such that travel of the watercraft can be bidirectional.

Inventors:
SHELANDER, Agustus Berman (1236 24th St, Unit ASanta Monica, California, 90404, US)
DE LA PUENTE, Vanesa Carla (1236 24th St, Unit ASanta Monica, California, 90404, US)
Application Number:
US2018/049285
Publication Date:
March 14, 2019
Filing Date:
September 01, 2018
Export Citation:
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Assignee:
SHELANDER, Agustus Berman (1236 24th St, Unit ASanta Monica, California, 90404, US)
DE LA PUENTE, Vanesa Carla (1236 24th St, Unit ASanta Monica, California, 90404, US)
International Classes:
B63B1/24; B63B35/79
Domestic Patent References:
WO2007088351A12007-08-09
Foreign References:
US20130102210A12013-04-25
US20010036780A12001-11-01
Attorney, Agent or Firm:
ROBERTS, Raymond E. (3350 Shelby Street Suite 20, Ontario California, 91764-5556, US)
Download PDF:
Claims:
CLAIM OR CLAIMS

What is claimed is: 1. A watercraft having a hull and two opposed intended axes of travel, comprising:

two hydrofoils mounted on the hull of the watercraft, wherein said hydrofoils are symmetric across a plane perpendicular to the intended axes of travel of the watercraft such that travel of the watercraft can be bidirectional. 2. The watercraft of claim 1, wherein:

said two hydrofoils are each mounted on the hull of the watercraft with at least two support structures. 3. The watercraft of claim 1, wherein:

said hydrofoils have an angle of attack such that said hydrofoil that is forward-most relative to a motion of the watercraft in either direction along the intended axes of travel produces lift of the watercraft. 4. The watercraft of claim 3, wherein:

said hydrofoils have an angle of attack such that said hydrofoil that is rearward-most relative to a motion of the watercraft in either direction along the intended axis of travel produces lift of the watercraft when said hydrofoil that is forward- most is near a surface of the water. 5. The watercraft of claim 1, wherein:

said hydrofoils are surface piercing type hydrofoils. 6. The watercraft of claim 1, wherein:

the watercraft is a kiteboard. 7. The watercraft of claim 6, wherein:

the watercraft is a twin-tip kiteboard.

8. The watercraft of claim 1, wherein: the watercraft is a foilboard. 9. The watercraft of claim 8, wherein: the watercraft is a twin-tip foilboard.

Description:
TITLE OF THE INVENTION BIDIRECTIONAL HYDROFOIL By inventors Agustus Berman Shelander and Vanesa Carla de la Puente CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No.62/557,058, filed Sept.11, 2017, hereby incorporated by reference in its entirety. COPYRIGHT NOTICE AND PERMISSION This document contains some material which is subject to copyright protection. The copyright owner has no objection to the reproduction with proper attribution of authorship and ownership and without alteration by anyone of this material as it appears in the files or records of the United States Patent and Trademark Office, but otherwise reserves all rights whatsoever. BACKGROUND OF THE INVENTION TECHNICAL FIELD The present invention relates generally to watercraft, and more particularly to such having more than one hydrofoil and wherein the craft is able to operate in two directions. BACKGROUND ART Hydrofoils can be used on a watercraft to decrease drag. Commonly, a hydrofoil operates efficiently in a single direction with a design that is asymmetric front to back. However, such an asymmetric design creates stability and lift only when the watercraft is moving in its single primary direction.

A popular example of such a watercraft is the kiteboard, a board on which a rider stands and is pulled by a kite. A kiteboard can include an attached hydrofoil, and then is alternately termed a“foilboard.” Current state of the art foilboards raise the board using a long center stake which is attached to a submerged hydrofoil that lifts the board entirely out of the water

U.S. Pat. No.9,056,654 by Fraser teaches a Hydrofoil And Water Sport Board Equipped Therewith; U.S. Pat. No.9,669,902 by Geislinger teaches a Hydrofoil; and U.S. Pat. No.9,789,935 by Aguera teaches a Hydrofoil-Based Apparatus, that is, all unidirectional foilboards. Similarly, U.S. Pat. App. Ser. No.2017/0355429 A1 by Lobisser teaches a Hydrofoil Assembly For Watersports And Associated Methods Of Manufacture also is a kiteboard/foilboard, albeit also unidirectional.

Two distinguishable examples of bidirectional foilboards are the“Brunotti RDP Glider Twintip Hydrofoil Kite Board” (see e.g., w_w_w.powerkiteshop.com/brunotti-rdp- glider.htm) and the“Ierofoil Amphidrome” (see e.g., w_w_w.foilever.com/en/kitefoil/90- ierofoil-kitefoil-adaptable-twintip.html). These are distinguishable in that the lifting foils are mounted to separate structures (as opposed to a central "mast") and perhaps more importantly because they are designed to interact with the surface of the water to create stability (whereas other current foilboards rely entirely on the rider to stabilize the system with the foils entirely submerged).

FIG.1 (Prior Art) is based on Lobisser and shows a kiteboard/foilboard 1 with typical features. This watercraft has a hull 2, a hydrofoil assembly 3, and a support fin 4 that attaches the hydrofoil assembly 3 to the hull 2. Note, the hydrofoil assembly 3 may be a complex assembly, as in FIG.1 or all of the art cited or it may be a simple hydrofoil. A salient feature of all of these prior art watercraft, however, is that they are unidirectional, depicted in FIG.1 by an arrow 5 representing the primary and essentially sole direction of motion possible.

Some watercraft should desirably operate equally well in two directions. For example, a twin-tip type kiteboard needs to have the same performance characteristics regardless of whether the rider is on a port or starboard tack, even though the kiteboard alternately moves through the water in opposite directions. BRIEF SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a solution to the problem of providing a pair of hydrofoils or hydrofoil assemblies that are mounted on a watercraft separately yet symmetrically so as to permit the watercraft to have the same performance characteristics when traveling in opposite directions.

Briefly, one preferred embodiment of the present invention is a watercraft having a hull and two opposed intended axes of travel. Two hydrofoils or hydrofoil assemblies are mounted on the hull of the watercraft, wherein these hydrofoils or hydrofoil assemblies are symmetric across a plane perpendicular to the intended axes of travel of the watercraft such that travel of the watercraft can be bidirectional.

These and other objects and advantages of the present invention will become clear to those skilled in the art in view of the description of the best presently known mode of carrying out the invention and the industrial applicability of the preferred embodiment as described herein and as illustrated in the figures of the drawings. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) The purposes and advantages of the present invention will be apparent from the following detailed description in conjunction with the appended figures of drawings in which:

FIG.1 (Prior Art) shows a kiteboard/foilboard with typical features;

FIG.2 is a side view of a watercraft in accord with the present invention;

FIG.3 is a perspective view of the watercraft in FIG.2; and

FIG.4 stylistically depicts how each hydrofoil is symmetric to a cross plane perpendicular to the intended axis of travel of the watercraft, which here may be bidirectional as represented by arrow heads at both ends of the shown axis of travel.

In the various figures of the drawings, like references are used to denote like or similar elements or steps. DETAILED DESCRIPTION OF THE INVENTION A preferred embodiment of the present invention is a bidirectional hydrofoil, as illustrated in the various drawings herein where embodiments of the invention are depicted by the general reference character 10. The current invention improves the performance of bi- directional watercraft with hydrofoils in a manner that permits operation of the watercraft equally well in opposite directions.

FIG.2 is a side view of a watercraft 10 in accord with the present invention, and FIG. 3 is a perspective view of the watercraft 10 in FIG.2. The watercraft 10 has a craft hull 12 and a pair of lifting hydrofoils 14 that are attached to the hull 12 with independent support structures 16 such that the hydrofoils 14 are symmetric across a plane 18 that is perpendicular to the intended axis of travel for the watercraft 10. As shown, there are two hydrofoils 14, one on each end of the hull 12, each having its own attachment or multiple attachment points to the hull 12.

In the inventor’s presently preferred embodiment the watercraft 10 is a twin-tip foilboard. The fins of a pre-existing twin-tip kiteboard replaced with the support structures 16 for a hydrofoil 14 at each end of the hull 12. The support structures 16 also serve the purpose of the vertical fins which they replace (e.g., the support fin 4 of the unidirectional a kiteboard/foilboard 1 in FIG.1 (Prior Art)).

Each hydrofoil 14 may or may not be symmetric across any plane which intersects the hydrofoil 14. However, as stylistically depicted in FIG.4, each hydrofoil 14 is symmetric to another cross plane 20 perpendicular to the intended axis of travel 22 of the watercraft 10, which here may be bidirectional as represented by arrow heads at both ends of the shown axis of travel 22. With reference back to FIG.2 as well, note plane 18 and cross plane 20 may be co-planar, and in all cases are planarly parallel. Note also that, relative to the current motion of the watercraft 10, one hydrofoil 14 may be forward-most and the other rearward-most. For example, the left-most end of the of the watercraft 10 in the figures may be forward-most.

The hydrofoils 14 are given an angle of attack (see e.g., expanded representation 24) such that whichever is forward-most relative to the current motion of the watercraft 10 produces lift and, if the speed of motion is great enough, lifts the then forward moving section of the watercraft 10 out of the water until the hydrofoil 14 interacts with the surface of the water, preventing the watercraft 10 from rising any further. The angle of attack given to the hydrofoils 14 is further such that when the forward hydrofoil 14 is interacting with the surface of the water the rearward hydrofoil 14 also generates lift, lifting the hull 12 of the watercraft 10 partly or wholly out of the water.

As noted above, the hydrofoils 14 by design are given a desired angle of attack to interact with the surface of the water. The hydrofoils 14 thus may be“surface piercing” type hydrofoils, which are common on boats as a way to control flying height, but which heretofore have not been applied to kiteboards. Furthermore, to focus on the core of the present invention the hydrofoils 14 depicted in the figures are simple hydrofoils, but more complex hydrofoil assemblies can alternately be used. While various embodiments have been described above, it should be understood that they have been presented by way of example only, and that the breadth and scope of the invention should not be limited by any of the above described exemplary embodiments, but should instead be defined only in accordance with the following claims and their equivalents.