GB2277301A

GB2277301A - Multi-hull board sail with hydrofoils

Info

Publication number: GB2277301A
Application number: GB9408047A
Authority: GB
Inventors: Richard John Winston Harvey
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-04-23
Filing date: 1994-04-22
Publication date: 1994-10-26
Anticipated expiration: 2014-04-22
Also published as: GB9308405D0; GB2277301B; GB9408047D0

Abstract

A multi-hull boardsail includes at least two parallel boards (10 and 11) joined together by a platform (12) releasably attached to each of the boards (10 and 11). A pair of rear foils (17) are filled in the skeg mountings at the rear of each board (10 and 11) and either a single front foil (14) or two separate front foils (14) is or are releasably mounted on the boards (10 and 11). <IMAGE>

Description

BOARDSAILS Field of the Invention This invention relates to boardsails, which are wellknown recreational and sporting craft.

In Patent Specification No. 2232935 (to which reference should be made) there is described and claimed a multi-hull boardsail comprising at least two boardsail boards each of which has a receptor for location of a mast fitting and a slot for reception of a keel, said boards being arranged in spaced parallel relationship and joined together by a platform which is releasably attached to each of the boards, said platform having front fittings which locate in the mast receptors of the boards and rear fittings which accept and retain the keels of the boards.

The boardsail of Specification No. 2232935 can be used, as described in the specification, for a number of purposes, including boardsail instruction.

It is an object of the present invention to provide an improved multi-hull boardsail.

Summary of the Invention According to a first aspect of the present invention there is provided a multi-hull boardsail comprising at least two boardsail boards arranged in spaced parallel relationship and joined together by a platform which is releasably attached to each of the boards, and front and rear foils releasably mounted on the boards.

If, therefore, there are two boards, the vessel will function at low speeds as a catamaran whereas, at higher speeds, the boards will rise out of the water and the front and rear foils of the two boards will provide stable support enabling the vessel to be sailed as a hydrofoil.

There may be a single front foil which includes a portion which extends between the boards beneath the platform.

Alternatively, two separate front foils may be provided.

The platform preferably includes a receptor for location of a mast fitting so that a single conventional boardsail mast can be used (as described in Specification No. 2232935). The platform is preferably releasably attached to the boards by means which engage with the mast receptors on the boards.

Releasable attachment of the platform is preferably further effected by means which engage with the daggerboard slots on the boards.

The front foil(s) is or are preferably mounted on the boards by means which cooperate with the daggerboard mounting slots of the boards.

The rear foils are preferably mounted in the skeg mountings of the boards.

According to a second aspect of the invention there is provided a method of adapting a boardsail comprising a sailboard and a skeg mounted at the rear of the sailboard, said method involving replacement of the skeg by a hydrofoil which is fitted releasably in the skeg mounting.

Brief Description of the Drawings Figure 1 is an isometric view of a hydrofoil catamaran, Figure 2 is a detail view showing the mounting of the front foil of the catamaran shown in Figure 1, Figure 3 is a detail view similar to Figure 2, but showing an alternative foil configuration, and Figure 4 is a detail view showing the mounting of the rear foil of the catamaran shown in Figure 1.

Description of the Preferred Embodiments The catamaran shown in Figure 1 comprises a pair of boardsail boards 10 and 11 joined releasably together by a platform 12. The platform 12 is formed as a plastic moulding or fabrication and includes a receptor for location of a mast fitting so that a conventional sailboard sail 13 can be mounted on the platform 12 at a position located on the axis of the catamaran, i.e. centrally between the two boards 10 and 11.

The platform 12 is mounted releasably on the two boards 10 and 11 by fittings which engage in the mast receptors and in the daggerboard slots of the two boards 10 and 11. The platform 12 is positioned between the daggerboard mounting slots of the two boards 10 and 11 so that a front hydrofoil 14 can be attached to the two boards 10 and 11 by bolts 15 which enter the daggerboard slots.

The hydrofoil 14 includes a part 14A which extends across the two boards 10 and 11 beneath the platform 12 and downwardly and inwardly inclined end portions 16 which terminate at positions beneath the boards 10 and 11, as can be seen from Figure 2.

Rear hydrofoils 17 are fitted in the skeg mountings at the rear of each board 10, 11. Each rear hydrofoil 17 includes a vertical stem 18, the upper end of which fits in the skeg mounting, and a pair of wings 19 and 20. The wings 19 and 20 may extend horizontally so that each rear hydrofoil 17 is in the form of a cross in vertical section. Alternatively, the wings 19 and 20 are inclined, as shown, at an angle of the order of 45 to the vertical and extend downwardly from the vertical stem 18.

In use, the multi-hull vessel can be sailed as a conventional sailboard, in the manner described in Patent Specification No. 2232935 to which reference should be made.

When, however, the vessel achieves the required speed, the two boards 10 and 11 will lift clear of the water and the vessel will be supported on the front foil 14 and the two rear foils 17. The catamaran configuration of the vessel will provide the required stability for the vessel when it is sailing on its foils.

In the alternative foil design shown in Figure 3, the single front foil 14 is replaced by two separate front foils 21, one mounted in the daggerboard mounting slot of each of the boards 10 and 11 and held in releasable engagement with the board 10, 11 as illustrated. Each separate front foil 21 includes an upper vertical stem portion 22 and a pair of relatively inclined wings 23 and 24.

In an alternative design, each outermost wing 24 is omitted.

It is envisaged that the boards 10 and 11 can be used separately on removal of the platform 12 and that a single board with a rear foil 17 will provide enhanced sailing characteristics.

Claims

Claims:

1. A multi-hull boardsail comprising at least two boardsail boards arranged in spaced parallel relationship and joined together by a platform which is releasably attached to each of the boards, and front and rear foils releasably mounted on the boards.

2. A multi-hull boardsail as claimed in Claim 1, which includes a single front foil which includes a portion which extends between the boards beneath the platform.

3. A multi-hull boardsail as claimed in Claim 1, which includes two separate front foils.

4. A multi-hull boardsail as claimed in any one of the preceding claims, in which the platform includes a receptor for location of a mast fitting so that a single conventional boardsail mast can be used.

5. A multi-hull boardsail as claimed in Claim 4, in which the platform is releasably attached to the boards by means which engage with the mast receptors on the boards.

6. A multi-hull boardsail as claimed in Claim 5, in which releasable attachment of the platform to the boards is further effected by means which engage with the daggerboard slots on the boards.

7. A multi-hull boardsail as claimed in Claim 2, in which the front foil is mounted on the boards by means which cooperate with the daggerboard mounting slots of the boards.

8. A multi-hull boardsail as claimed in Claim 3, in which the front foils are mounted on the boards by means which cooperate with the daggerboard mounting slots of the boards.

9. A multi-hull boardsail as claimed in any one of the preceding claims, in which the rear foils are mounted in the skeg mountings of the boards.

10. A multi-hull boardsail as claimed in Claim 1 and substantially as hereinbefore described with reference to and as shown in Figure 1 of the accompanying drawings.

11. A multi-hull boardsail as claimed in Claim 10, which includes a single front foil substantially as hereinbefore described with reference to and as shown in Figure 2 of the accompanying drawings.

12. A multi-hull boardsail as claimed in Claim 10, which includes two front foils each substantially as hereinbefore described with reference to and as shown in Figure 3 of the accompanying drawings.

13. A multi-hull boardsail as claimed in Claim 10, which includes rear foils substantially as hereinbefore described with reference to and as shown in Figure 4 of the accompanying drawings.

14. A method of adapting a boardsail comprising a sailboard and a skeg mounted at the rear of the sailboard, said method involving replacement of the skeg by a hydrofoil which is fitted releasably in the skeg mounting.

15. A method as claimed in Claim 14 and substantially as hereinbefore described with reference to the accompanying drawings.