GB1581626A

GB1581626A - Device to increase the sail carrying power of sailing vessels

Info

Publication number: GB1581626A
Application number: GB52842/75A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-03-22
Filing date: 1977-03-22
Publication date: 1980-12-17

Description

(54) A DEVICE TO INCREASE THE SAIL CARRYING POWER OF SAILING VESSELS (71) I, JoHN G. WALKER being of British nationality, formerly of, Ayias Lavras 10, Ano Glyfada, Greece, now of, 14 Winchmore Drive, Trflmpington, Cambridgeshire, do hereby declare the invention, for which Í pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to stabilising arms for sailing vessels.

The sail carrying power of a vessel may be increased by providing stabilisers which are arranged to provide an upward or downward force depending on whether they are used on the windward or leeward side of the boat.

It is desirable to have a single stabiliser which may be used to sail both tacks, and which may be retracted when it is not required.

Accordingly the invention provides a stabilising arm for a sailing vessel comprising an outboard stabiliser carried on an arm which is pivotable about an upright axis from one side of the vessel to the other.

In a preferred embodiment of the invention a stabiliser may be pivotally mounted on the arm so that it is weathercocking. The term weathercocking implies that the stabiliser adopts the position of minimum resistance with respect to the relative water flow.

The stabilising arm may be pivotable over or around the bow or stern of the vessel. In one embodiment the stabiliser may comprise a hydrofoil which may be inclined towards the vessel when the vessel is upright so that the output force of the hydrofoil comprises a horizontal component.

The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a perspective view of an embodiment of the invention, and Figure 2 is an end view of another embodi ment of the invention.

Referring to Figure 1 an arm A is hinged on an axis B placed in the plane of symmetry of a vessel C so that it can swing freely from one approximately lateral position, over either bow or stern, to an opposite approximately lateral position, being positioned to one side or the other depending on which tack is being sailed. It will usually be so arranged as to always be positioned on the leeward side but it may also be arranged to always be positioned on the windward side, depending on the configuration of the boat and the action of a stabiliser D attached to the outboard end of the arm A, The arm may be pulled into position and retained by wires as indicated. In the drawing the sails are omitted for the sake of clarity.

If the device D fitted to the outboard end of the arm when the arm is positioned to leeward is capable of exerting upward force, e.g. such as a buoyant float, a water ski, a hydrofoil, or any combination of the three, then a considerable increase of sail carrying power will be experienced by the vessel This will either be continuous, and irrespective of the forward speed of the vessel, as in the case of a buoyant float, or dependent upon the forward speed of the vessel as in the cases of the water ski and the hydrofoil. The upward lifting device may be joined to the arm by a pivot E so as to weathercock to the local direction of water flow, being equipped with its own small tail fin F or other system to ensure directional stability.If on the other hand the arm is arranged so as to function always on the windward side, then some device must be used capable of exerting downwards force, such as a weight (which may be either permanent, or temporary, such as scooped up water ballast) or a downwards pulling hydrofoil.

If the arm is fitted with a hydrofoil as its sail carrying power device, either alone or in conjunction with others, then this hydrofoil may, by being angled as shown at A in Figure 2, be arranged to provide not only a "sail carrying" component of force, H but also a lateral component of force G, to maintain a given course, and in this case may replace the conventional keel or centreboard.

In this case the pivot E in Figure 1 will be inclined as shown in Figure 2. If this c-on- figuration is adapted for windward side use, then the force arrows will be in the opposite sense.

The arm may also be arranged, by cams or other means to interfere with the power setting controls of the sails so as to permit full power only when the arm is properly set laterally, automatically closing down the sail drive setting while the arm is moved from one side of the vessel to the other during, for example, tacking manoeuvres.

When the configuration of the sail carrying power device mounted at the end of the arm is such that it requires some depth of water to operate well, it may be useful to reduce the depth of water needed when the arm is in the "ahead or astern in line" non-operating position.

This may be achieved with an upright arm pivot on the vessel by setting the geometry of the arm so that in the "ahead or astern in line" position the sail carrying power device is either at or just above the water surface.

However, when the arm is rigged out to one side, the vessel will need to be heeled to immerse the device so as to function. The necessity for heeling may be eliminated by inclining the upright bearing, so that the top is inclined forwards if the arm is to swing over the stern, or aft if the arm is to swing over the bow, so as to produce a skew hinge effect. The geometry of the arm is arranged so that the sail carrying power device is at or just above the water level when the arm is in the "ahead or astern in line" position and by correct choice of the skew of the inboard pivot, the outboard end of the arm will descend as it goes towards the final approximately lateral operating position at which the sail carrying power device will have the correct immersion to function with the vessel remaining upright.

The axis of pivoting of the lateral arm to the vessel should remain in the plane of symmetry of the vessel, so that port and starboard effects will be symmetrical.

Reference is hereby made to my copending application 52841/75 (Serial No.

1581625) which sailing vessel with weathercocking hydrofoils are described and claimed.

WHAT I CLAIM IS: 1. A stabilising arm for a sailing vessel comprising an outboard stabiliser carried on an arm which is pivotable about an upright axis from one side of the vessel to the other.

2. A stabilising arm according to claim 1 in which the arm is pivotable aftwards over or around the stern of the vessel.

3. A stabilising arm according to claim 1 in which the arm is pivotable forwards over or around the bow of the vessel.

4. A stabilising arm according to any preceding claim which is mounted so that as it is pivoted towards the bow or stern the outboard end of the arm is raised.

5. A stabilising arm according to claim 4 in which the stabiliser is raised out of effective contact with the water when the arm is aligned with the vessel's median.

6. A stabilising arm according to claim 4 or claim 5 in which the upright axis is inclined forwards so that the outboard end of the arm is elevated as it is pivoted aftwards.

7. A stabilising arm according to claim 4 or claim 5 in which the upright axis is inclined aftwards so that the outboard end of the arm is elevated as it is pivoted towards the bow of the vessel.

8. A stabilising arm according to any preceding claim which is operatively linked to the sails of the vessel so that the sails are responsive to the pivoting of the arm.

9. A stabilising arm according to claim 8 which, when mounted on a vessel inhibits full drive unless the stabilising arm is correctly, laterally rigged.

10. A stabilising arm according to claim 8 or claim 9 in which the arm is operatively linked to the sails by a cam.

11. A stabilising arm according to any preceding claim in which the stabiliser is pivotally connected to the arm so that the stabiliser is weathercocking.

12. A stabilising arm according to any preceding claim in which the stabiliser is adapted for use on the leeward side of the sailing vessel.

13. A stabilising arm according to any preceding claim in which the stabiliser comprises a buoyant float.

14. A stabilising arm according to any one of claims 1-12 in which the stabiliser comprises a water ski.

15. A stabilising arm according to any one of claims 1-12 in which the stabiliser comprises an upwardly acting hydrofoil.

16. A stabilising arm according to any of claims 1-11 in which the stabiliser is adapted for use on the windward side of the sailing vessel.

17. A stabilising arm according to claim 16 in which the stabiliser comprises a permanent ballast.

18. A stabilising arm according to claim 16 in which the stabiliser comprises temporary ballast which is provided by scooping up water into a tank.

19. A stabilising arm according to claim 16 in which the stabiliser comprises a downwardly acting hydrofoil.

20. A stabilising arm according to claim 15 or claim 19 in which the hydrofoil is inclined towards the vessel when the vessel is upright so that the output force of the hydrofoil comprises a horizontal component of force.

21. A stabilising arm according to any preceding claim in which the stabiliser is pivotable about an upright axis so that the stabiliser is weathercocking.

22. A stabilising arm according to claim 21 when dependent upon claim 15 or claim 19 in which the top of the upright pivot axis is inclined towards the vessel when the vessel

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Claims

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other means to interfere with the power setting controls of the sails so as to permit full power only when the arm is properly set laterally, automatically closing down the sail drive setting while the arm is moved from one side of the vessel to the other during, for example, tacking manoeuvres.

When the configuration of the sail carrying power device mounted at the end of the arm is such that it requires some depth of water to operate well, it may be useful to reduce the depth of water needed when the arm is in the "ahead or astern in line" non-operating position.

This may be achieved with an upright arm pivot on the vessel by setting the geometry of the arm so that in the "ahead or astern in line" position the sail carrying power device is either at or just above the water surface.

However, when the arm is rigged out to one side, the vessel will need to be heeled to immerse the device so as to function. The necessity for heeling may be eliminated by inclining the upright bearing, so that the top is inclined forwards if the arm is to swing over the stern, or aft if the arm is to swing over the bow, so as to produce a skew hinge effect. The geometry of the arm is arranged so that the sail carrying power device is at or just above the water level when the arm is in the "ahead or astern in line" position and by correct choice of the skew of the inboard pivot, the outboard end of the arm will descend as it goes towards the final approximately lateral operating position at which the sail carrying power device will have the correct immersion to function with the vessel remaining upright.

The axis of pivoting of the lateral arm to the vessel should remain in the plane of symmetry of the vessel, so that port and starboard effects will be symmetrical.

Reference is hereby made to my copending application 52841/75 (Serial No.

1581625) which sailing vessel with weathercocking hydrofoils are described and claimed.

WHAT I CLAIM IS: 1. A stabilising arm for a sailing vessel comprising an outboard stabiliser carried on an arm which is pivotable about an upright axis from one side of the vessel to the other.
2. A stabilising arm according to claim 1 in which the arm is pivotable aftwards over or around the stern of the vessel.
3. A stabilising arm according to claim 1 in which the arm is pivotable forwards over or around the bow of the vessel.
4. A stabilising arm according to any preceding claim which is mounted so that as it is pivoted towards the bow or stern the outboard end of the arm is raised.
5. A stabilising arm according to claim 4 in which the stabiliser is raised out of effective contact with the water when the arm is aligned with the vessel's median.
6. A stabilising arm according to claim 4 or claim 5 in which the upright axis is inclined forwards so that the outboard end of the arm is elevated as it is pivoted aftwards.
7. A stabilising arm according to claim 4 or claim 5 in which the upright axis is inclined aftwards so that the outboard end of the arm is elevated as it is pivoted towards the bow of the vessel.
8. A stabilising arm according to any preceding claim which is operatively linked to the sails of the vessel so that the sails are responsive to the pivoting of the arm.
9. A stabilising arm according to claim 8 which, when mounted on a vessel inhibits full drive unless the stabilising arm is correctly, laterally rigged.
10. A stabilising arm according to claim 8 or claim 9 in which the arm is operatively linked to the sails by a cam.
11. A stabilising arm according to any preceding claim in which the stabiliser is pivotally connected to the arm so that the stabiliser is weathercocking.
12. A stabilising arm according to any preceding claim in which the stabiliser is adapted for use on the leeward side of the sailing vessel.
13. A stabilising arm according to any preceding claim in which the stabiliser comprises a buoyant float.
14. A stabilising arm according to any one of claims 1-12 in which the stabiliser comprises a water ski.
15. A stabilising arm according to any one of claims 1-12 in which the stabiliser comprises an upwardly acting hydrofoil.
16. A stabilising arm according to any of claims 1-11 in which the stabiliser is adapted for use on the windward side of the sailing vessel.
17. A stabilising arm according to claim 16 in which the stabiliser comprises a permanent ballast.
18. A stabilising arm according to claim 16 in which the stabiliser comprises temporary ballast which is provided by scooping up water into a tank.
19. A stabilising arm according to claim 16 in which the stabiliser comprises a downwardly acting hydrofoil.
20. A stabilising arm according to claim 15 or claim 19 in which the hydrofoil is inclined towards the vessel when the vessel is upright so that the output force of the hydrofoil comprises a horizontal component of force.
21. A stabilising arm according to any preceding claim in which the stabiliser is pivotable about an upright axis so that the stabiliser is weathercocking.
22. A stabilising arm according to claim 21 when dependent upon claim 15 or claim 19 in which the top of the upright pivot axis is inclined towards the vessel when the vessel

is upright so that the output force of the hydrofoil comprises a horizontal component of force.
23. A stabilising arm according to claim 21 when dependent upon claim 15 or claim 19 in which the top of the upright pivot axis is inclined towards the vessel when the vessel is upright so that the output force of the hydrofoil provides a leeway of resisting effect.
24. A stabilising arm substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.
25. A vessel comprising stabilising arm according to any preceding claim.