GB2229984A - Sail assembly with booms for fore and mainsails rigidly connected to mast - Google Patents

Abstract

A sail rig for a watercraft comprising a boom for a foresail and a boom for a mainsail, both booms rigidly fixed to a mast. <IMAGE>

Description

SAIL RIG This invention relates to sail rigs and the like for watercraft.

According to one aspect of the present invention a sail rig for a watercraft comprises a boom for a foresail and a boom for a mainsail, both booms being rigidly fixed to a mast.

Preferably means are provided for rotating the mast and for retaining the mast in the required position, which means are preferably independent of the means controlling the set of the sails on the booms.

According to a second aspect of the present invention a sail rig for a watercraft comprises a foresail, a mainsail and a mast, the arrangement being such that the foresail and mainsail form with the mast a continuous aero foil.

According to a further aspect of the invention a mast for a watercraft comprises a first groove to receive the leading edge of a mainsail and a second groove to receive the trailing edge of a foresail. The continuous aerofoil may thus be obtained with this arrangement.

In one construction the booms may have means eg. horses, at their outer ends for permitting lateral movement respectively of the foresail and mainsail, such means being in the form of for example a frame of rhombus shape in plan and being of tubular or similar structure and over which means attached to the sails can slide. Alternatively the horses may be of arcuate shape.

Preferably these latter means are controlled by an endless rope system attached appropriately to the booms fore and aft, and extending around pulleys. With this arrangement the helmsman and/or crew can be positioned other than in the conventional position simply by arranging the ropes and pulleys to lead to an appropriately preferred location. In this case, the means for controlling the angle of the mast would also be similarly arranged, with conventional tiller controls being similarly arranged.

The invention may be performed in various ways and one specific embodiment will now be described by way of example with reference to the accompanying drawings in which: Figure 1 - is a general view of a craft incorporating the present invention, Figure 2 - is a plan view of a boom for use with the present invention, Figure 3 - is a diagrammatic representation in plan showing the sails, mast and using an arcuate shaped horse and Figure 4 - is a similar view to Figure 3 showing the shape assumed with the wind in the direction shown by the arrow.

As shown in Figure 1 a sail rig comprises a mast 10 a foresail 11 and a mainsail 12. The mast has a rearwardly directed groove (not shown) in which the leading edge of the mainsail is channelled and a further groove arranged at a 1800 thereto in which the rear edge of the foresail is similarly channelled.

The base of the mast is housed in a bearing sleeve 13 which is rigidly secured to the hull of the craft. This allows the mast to be rotated.

Referring now to Figure 2 there is shown a forward boom 16 and a rear boom 17. The forward boom 16 is rigidly secured to the mast while the rear boom 17 is similarly rigidly secured at 1800 to the forward boom so that the forward and rear booms 16 and 17 form a continuous structure with the mast 10 in line with the grooves in the mast.

The front end of the forward boom is provided with two outwardly directed portions 21 and 22 arranged to form with two portions 23 and 24 a rhombus shaped frame with rounded corners 25 and 26 formed as recesses. The aft end of the rearward boom is similarly formed as a rhombus shaped frame with corresponding portions 27, 28, 30 and 31, the angles between the portions being slightly different.

The front end of the forward boom receives the forward end of the foresail and the rear end of the rear boom receives the rear end of the mainsail through conventional sliding hook attachments thus permitting lateral movement of the sails separately from the means of altering the angle of the mast and booms.

Although the frames, or horses, have been shown as rhombus shaped they may be other shapes, eg arcuate. Such an arrangement is shown in figures 3 and 4 and which will be described in more detail below.

With the arrangement described the foresail, mast and mainsail form a continuous aerofoil surface. The invention provides the facility to change the set of the sails to accord with the wind direction, and at the same time to vary the depth of camber progressively as demanded by the wind conditions and/or characteristics of the water craft. The preferred arrangement and which is described here is the use of horses in the form of arcs. With the sails set along the centre lines of the boom with their outer edges positioned in the centres of the tracks of the horses, ie. in the middle of the arcs the sails are feathered and flat showing no camber and the rig would weathercock, no driving force being imparted to the sails. This arrangement is shown in figure 3.

Depending on the point of sailing selected sails would be drawn across the horses eg. for a port tack their outer edges would be hauled towards the port side.

This movement as shown in figure 4 would reduce the 'chord lengths of the sails and introduce a fullness or camber which would progressively increase as the sails moved further towards the outer points of the horses and were filled by the wind. The mast and boom fixed thereto would be rotated so as to cause the wind to strike the sails at the most effective angle of incidence to the line of the chord of the sail combination.

This arrangement and the controls provided allow both the camber of the sails and the angle of the rig to the wind to be adjusted easily and precisely to the most efficient settings according to the prevailing conditions.

This degree of control is obtained with the advantages of using conventional, soft or fabric sails and equipment and techniques usually employed in the rigging of sail craft without recourse to rigid structures and aerofoils of inflexible material.

The fabric sails may be double surfaced, in which event twin grooves to receive the edges of the sails would be provided on both sides of the mast.

The sail rig can be used with a conventional hull or with any other desired form.

In an alternative arrangement the sails may be attached to the mast and the booms in a conventional manner, ie, without forming a continuous aerofoil with the mast but leaving the trailing edge of the foresail free of the mast and allowing lateral movement by providing a horse attachment to the mast with a sliding attachment for the sail or fairleads at its ends for the controlling sheets. In this event, the leading edge of the foresail would be secured to the front end of the forward boom.

The facility of adjusting the angle of the booms and mast independently of the attitude of the boat by rotating the mast would be retained.

In this way a conventional style of sail rig as commonly employed could be used in conjunction with the arrangement of booms fixed rigidly to a rotating mast with the added advantage of adjusting the sail independently of the direction boat and steering the boat independently of the wind.

Claims (10)

1) A sail rig for a watercraft comprising a boom for a foresail and a boom for a mainsail, both booms rigidly fixed to a mast.

2) A sail rig as claimed in Claim 1, in which means are provided for rotating the mast and for retaining the mast in the required position.

3) A sail rig as claimed in Claim 2, in which the means for rotating and retaining the mast are independent of means controlling the set of the sails on the booms.

4) A sail rig as claimed in any one of Claims 1 to 3, including a foresail and a mainsail in which the arrangement is such that the foresail and mainsail form with the mast a continuous aerofoil.

5) A sail rig as claimed in Claim 4, in which the mast has a first groove to receive the mainsail and a second groove to receive the foresail.

6) A sail rig as claimed in any one of the preceding Claims, in which the booms have means for permitting lateral movement respectively of the foresail and mainsail.

7) A sail rig as claimed in Claim 6, in which the means permitting lateral movement comprise rhombus shaped frames adjacent the ends of the respective booms over which means attached to the sails can slide.

8) A sail rig as claimed in Claim 6, in which the means permitting lateral movement comprise arcuate shaped frames adjacent the ends of the respective booms over which means attached the sails can slide.

9) A sail rig as claimed in Claim 7 or Claim 8, in which the booms are controlled by an endless rope system attached appropriately to the booms fore and aft and extending around pulleys.

10) A watercraft including a sail rig as claimed in any one of the preceding Claims.