GB2128153A - Sailboats - Google Patents

Abstract

A sailboat has a hull 10 having two ends and a mast 14 for supporting a sail 15 having a sheet 17 at each end of the foot thereof, the hull being provided with at least two sheet leads 16, one disposed between the mast and one end of the hull and the other disposed between the mast and the other end of the hull. The hull is substantially symmetrical about a transverse centre-line so that the hull can move through water with equal efficiency in each direction. The mast is stepped offset from the centre-line of the hull. <IMAGE>

Description

SPECIFICATION Sailboats This invention relates to sailboats.

Sailboats generally comprise a hull with an upwardly projecting mast to support one or more sails.

Sails may extend in front of the mast and in this case usually have their leading edge or luff retained on a forestay. Sails may also extend behind the mast and in this case the leading edge or luff is generally retained on the mast.

Other forms of sails include square sails suspended from an arm supported by the mast and triangular sails supported by an arm such as a 'lateen' rig.

In all these sail arrangements it is necessary to 'go about' or 'gybe' by steering the boat relative to the wind so as to allow the wind to act on the other side of the sail(s) so that the sail is disposed on the opposite side of the boat from that on which it was disposed prior to making the manoeuvre.

It is an object of the present invention to provide a novel sailboat which is relatively simple to construct, rig and sail. More specifically, it is an object of the invention to provide a sailboat which can be sailed to windward without undertaking the manoeuvre 'going about'.

According to the present invention I provide a sailboat comprising a hull having a mast projecting therefrom, a sail supported by said mast adapted to receive a sheet at each end of the foot of the sail, the hull being provided with at least two sheet leads, one disposed forward of the mast and one disposed aft of the mast.

Conveniently, the leads are provided at or near the ends of the hull.

Advantageously the hull is symmetrical at least about a transverse centre-line so that the hull can move through water with equal efficiency in each direction.

It is desirable that the mast step is offset from the centre-line of the hull towards one gunwale and is preferably as near to the gunwale as strength considerations will permit.

The advantages of a sailboat constructed in accordance with the invention will be apparent from the following description of particular embodiments of the invention.

Reference is made to the drawings, in which Figure 1 is a perspective view of a sailboat according to the invention; Figure 2 is a cross-section of a sailboat shown in Figure 1; Figures 3a and 3b illustrate in plan and side elevation how the sailboat sails in different directions relative to the wind; Figures 4a and 4b show schematically two types of sail which may be employed; Figures 5a, b, c, d and e show different mast head arrangements; and Figures 6a, b, c and d illustrate how the sailboat can be steered.

Referring to Figure 2 the sailboat comprises a hull 10 having a centre thwart 11 with a centreboard or daggerboard case 12. The hull 10 is symmetrical about both a longitudinal and transverse axis and terminates in a bow/stern 13 at each end.

A mast 14 supports a symmetrical isosceles triangular-shaped sail 15 and a sheet 17 is attached at each end of the foot of the sail and passed through leads 16 at each end of the boat and jam-cleats 1 6a (optional).

The mast 14 is stepped at 18 in a position offset from the longitudinal axis of the hull 10. The mast 14 may be unstayed as shown or may have one or more stays attached to the hull. Build-in buoyancy chambers extend along each side of the hull.

In Figure 1 a daggerboard 19 is shown in position.

The hull is, in this embodiment, of flat-bottomed construction comprising side panels 10a and a bottom panel 10b, with a shallow keel extending along the length of the boat.

The manner of sailing the boat is illustrated in Figure 3. With the wind direction as shown the boat will sail in the direction of the arrow when in the configuration shown. In this case the sheet 17 to the bow (for the time-being) of the boat acts as a luff-rope and the sail controlled by the other sheet 17 which is attached to the stern (for the time-being) of the boat. When it is desired to sail in the opposite direction it is not necessary to 'go-about' or 'gybe' but merely to release the luff-sheet and haul in the other sheet which will then act as a luff-rope and the sail can be controlled by the sheet attached to the stern (for the time-being). It will be seen that during this maneouvre the sail stays disposed on the leeward side of the mast at all times.

It will be apparent that the boat can change direction as required relative to the wind as in the case of a normal sailboat except that when a normal sailboat needs to 'go-about' or 'gybe' a boat according to the invention merely changes its direction of travel. All that is required of the sailor to undertake this maneouvre is to release one sheet and haul in the other sheet and it is not necessary for him to change his position in the boat.

The sailboat shown is designed so that the balance of the forces between the centre of effort of the sail and the centre of lateral resistance of the hull controls the direction of the boat. Whilst a simple daggerboard 19 is shown it will be appreciated that it could be replaced by a pivoted centre-board which would facilitate adjustment of the centre of lateral resistance by the sailorwhilst under way.

Movement of the centre of effort of the sails is enhanced by the use of a flexible mast.

Movement of the centre of effort of the sails when changing from one sailing mode to the opposite sailing mode can also be enhanced by the various alternative arrangements shown in Figure 5.

In Figure 5a the head of the sail is held close to the mast head giving very little change of centre of effort on changing mode. In Figure 5b a relatively slack halyard 20 is employed to obtain some movement.

In Figure Sc movement of the centre of effort is produced in a controlled manner by means of a triangular head-fitting 21 which is pivoted to the mast at 22 and 23 and attached to the head of the sail 15 at 24. When the direction of travel of the hull is reversed the fitting 21 moves to its other extreme position shown in dashed lines or a position intermediate the two extreme positions.

An alternative head-fitting 25 is shown in Figure 5d the operation being similar to that described with reference to Figure Sc except that the fitting 25 holds the head of the sail 15 spaced from the mast and the head is supported by halyard 20 attached. It will be appreciated that the head-fittings 24 and 25 can pivot relative to a fixed mast or a rotatable mast or may be fixed to a pivoted mast.

Afurther alternative is shown in Figure 5e in which the mast head is turned over at 26 to support the head of the sail and the mast is a rotatable mast.

The sail can be of any suitable shape but is preferably symmetrical about a centre-line. Figure 4a illustrates a triangular sail whilst Figure 4b illustrates a square sail supported by a top boom 26 attached to the mast-head or head-fitting if provided, and, if desired, a bottom boom 27. The sail shown includes battens 28 in the manner of a junk-rig sail but it will be apparent that any sail employed can be battened or unbattened as required.

The hull may be symmetrical or asymmetrical and may be of any desired shape or construction, including multichine or round bilge. A keel may be provided if required.

The manner of steering the boat is shown in Figure 6. The sailor steers by changing his weight position relative to the hull to produce a controlled heel, the heel shown in Figure 6a producing a turn to starboard and the heel shown in Figure 6b producing a turn to port. The rate of turn will of course depend upon the amount of heel for any given hull shape.

In the embodiment described above the centreboard or daggerboard lies on the longitudinal axis of the boat but, if desired, the centreboard or daggerboard can be spaced from that axis towards one of the gunwales. It is possible, in an extreme case, to replace the daggerboard or centreboard by a leeboard.

Situating the centreboard or daggerboard on the mast side of the boat or using a lee-board considerably increases the useful space in the boat and a hull with smooth internal lines can be designed without awkward projections such as a daggerboard case.

The invention is also applicable to multihull craft.

The mast can be stepped on one of the hulls or on a bridge member between two hulls. Suitable multihull constructions include proas, catamarans and trimarans.

It will be appreciated from the foregoing description that the invention provides a sailboat which is simple to manufacture, simple to rig and simple to sail. Whilst the absence of steering means, such as a rudder, makes the boat very simple to construct and rig, steering means such as rudders can be provided if required.

Claims (9)

1. A sailboat comprising a hull having two ends and a mast for supporting a sail having a sheet at each end of the foot thereof, the hull being provided with at least two sheet leads, one disposed between the mast and one end of the hull and the other disposed between the mast and the other end of the hull.

2. A sailboat according to Claim 1 which is substantially symmetrical about a transverse centreline so that the hull can move through water with equal efficiency in each direction.

3. A sailboat according to Claim 1 or 2 in which the mast is stepped offset from the centre-line of the hull.

4. A sailboat according to any of Claims 1 to 3 in which the hull is adapted to be steered by the trim thereof whereby the requirement for steering means is obviated.

5. A sailboat according to any of Claims 1 to 4 in which the hull incorporates built-in buoyancy chambers.

6. A sailboat according to any of Claims 1 to 5 which is generally flat bottomed.

7. A sailboat according to any of Claims 1 to 6 in which a shallow keel extends along at least a substantial portion of the length of the hull.

8. A sailboat according to any of Claims 1 to 7 provided with a daggerboard or centreboard.

9. A sailboat substantially as herein described with reference to the accompanying drawings.