Title:
Sail rig
Kind Code:
A1


Abstract:
A wind-propelled vehicle, particularly a multi-hulled sailing vessel, in which instead of mast, the upper spar (14) of the sail (13) is supported from a carrier (13) which moves athwart the vessel in a track in the form of an arch (16).



Inventors:
Roberts, Ronald Boyd (Darwin, AU)
Application Number:
10/161322
Publication Date:
12/05/2002
Filing Date:
05/31/2002
Assignee:
Strathcona (NT) Pty Ltd. (Leanyer, AU)
Primary Class:
Other Classes:
114/39.26, 114/39.32, 114/90, 114/102.29
International Classes:
B63B15/00; B63H9/06; (IPC1-7): B63H9/04; B63B15/00
View Patent Images:



Primary Examiner:
BASINGER, SHERMAN D
Attorney, Agent or Firm:
Egbert Law Offices, PLLC (Houston, TX, US)
Claims:

I claim:



1. A wind-propelled vehicle having a rigging of the crab-claw type, the vehicle including a sail having an upper spar and a lower spar, characterized in that the sail is supported by the connection of the upper spar to means capable of movement athwart the vehicle.

2. A vehicle according to claim 1, in which said means includes a moveable support mounted to travel athwart the vessel on a track.

3. A vehicle according to claim 2, in which said track is configured in an arc extending across the vessel.

4. A vehicle according to claim 3, in which the track is in the form of an arch the feet of which are mounted on either side of the vehicle.

5. A vehicle according to claim 4, said vehicle being a catamaran, the feet of the arch being mounted on respective hulls of the catamaran.

6. A vehicle according to claim 5, in which the feet of the arch are mounted for fore and aft movement.

7. A vehicle according to claim 6, in which said arch is capable of being tilted fore and aft.

8. A vehicle according to claim 2 in which longitudinal position of the sail relative to the support is such that the fore and aft portions of the sail are substantially balanced.

Description:

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0001] Not applicable.

REFERENCE TO MICROFICHE APPENDIX

[0002] Not applicable.

FIELD OF THE INVENTION

[0003] This invention relates to sail-powered vessels or vehicles. Although it is of general applicability, the invention has particular application to catamarans and other multi-hulled vessels, and will be particularly described by reference to its application to a catamaran.

[0004] An object of the invention is to provide a method of supporting a sail of the “crab claw” type, such that the limitations of known methods of rigging such sails are to a useful extent avoided.

BACKGROUND OF THE INVENTION

[0005] The crab claw sail has been known since the ancient Polynesians. In its common form it consists of a triangular sail suspended between an upper and a lower spar, the spars converging towards the forward end of the sail where the sail is fixed in the region of the bow. The top spar is attached to a mast with the sail on the leeward side of the mast, and the bottom spar is attached to the hull.

[0006] Such a sail configuration is difficult to tack. Because the sail must be located on the leeward side of the mast, in tacking the sail must be lowered and moved to the other side of the mast, then raised again. The sail is furthermore difficult to reef.

BRIEF SUMMARY OF THE INVENTION

[0007] In accordance with the present invention, the upper spar of the sail is supported by means including a support device capable of movement athwart the vessel. The support device may, in one possible embodiment of the invention, take the form of a moveable support mounted to travel athwart the vessel on a track. The path of the support device may be arcuate, in which case the track referred to may be configured in an arc extending across the vessel. (In this context it is not intended by the use of the word “arc,” that the arc must be part of a circle. For example, it may be elliptical or formed by merging two or more curves.)

[0008] Broadly, therefore, the invention resides in a wind-propelled vehicle having a rigging of the crab-claw type, the vehicle including a sail having an upper spar and a lower spar, characterized in that the sail is supported by the connection of the upper spar to means capable of movement athwart the vehicle. Preferably the support means includes a moveable support mounted to travel athwart the vessel on a track, and preferably the track is configured in an arc extending across the vessel.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0009] An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0010] FIG. 1 is a side elevation of a catamaran embodying the invention.

[0011] FIG. 2 is an end elevation of the catamaran of FIG. 1 from the bow.

[0012] FIGS. 3-5 show details of a carrier.

[0013] FIG. 6 shows in side elevation an arch mounting arrangement, and

[0014] FIG. 7 is an end elevation of the arrangement shown in FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

[0015] The illustrated catamaran includes a pair of hulls 10, a deck 11 and superstructure 12, and carries a crab claw sail 13 with top spar 14 and bottom spar 15. In accordance with the invention, the vessel does not have a mast but rather the sail is supported by means of a structure which in this embodiment takes the form of an arch 16 the feet of which are mounted on either side of the deck.

[0016] Mounted on the arch 16 for movement around the arch is a carrier 17, supporting a block (not shown) which supports the top spar 14. The lower spar 15 is restrained by a sheet 19 fixed to a carrier running in a track fixed across the deck or superstructure, in the region of the plane of the arch. The longitudinal position of the sail relative to the arch is such that the fore and aft portions of the sail are substantially balanced. As well as allowing for simple control of the sail, this allows gentle gybing.

[0017] The arch 16 in this embodiment consists of a pair of tubular rails 20 interconnected by a cross-bracing lattice structure 21. The feet of the arch are supported on the deck of the catamaran and guided by rails 22, as will be described in more detail below.

[0018] FIGS. 3-5 show the carrier 17 in more detail. It will be seen to include a box-like frame 23 which embraces the arch, with upper, lower and outside wheels 24,25, 26 which engage the side rails 20 of the arch to support and guide the carrier. Each of the wheels may be mounted by means of an axle 27 fixed in place by a pair of U-bolts 28.

[0019] A centrally located stiffening flange 29 is provided on the lower surface of the carrier 17, for the support of a block (not shown) from which the upper spar 14 is suspended. The upper wall of the carrier is provided with a pair of flanges 30 which provide anchoring for a pair of ropes (not shown) which pass downwardly over the arch towards the deck for movement of the carrier around the arch.

[0020] While the arch 16 can be fixedly mounted to the deck, it is preferred that it be mounted in such as way as to allow a certain amount of fore-and-aft movement, and also pivoting movement. FIGS. 6 and 7 illustrate one way of achieving this.

[0021] A pair of flanged rails 22 are fixed to the deck on each side of the vessel, and the feet of the arch are supported on runners 32, which rest on wheels 33 which can roll along the deck, trapped between the deck and the flange 34 of the rail 22. The wheels 33 run on axles fixed to the outer flanges 35a of the runners 32, which also have inner flanges 35b located inboard of the rails 22.

[0022] The fore and aft position of the arch is fixed by means of pins 36 which pass through the flange 35b and may be engaged in selected ones of a series of holes 37 drilled through the flanges 35a and 35b at regular spacing (suitably 250 mm). Similar holes are drilled in the rail 22 at 500 mm intervals. In this way the fore and aft position of the arch can be adjusted in regular increments (in this case 250 mm). A locking arrangement (not shown) is provided for the pins. In the course of adjusting the position of the arch, it will be prevented from toppling by the engagement of the wheels 33 with the flanges of the rail 22.

[0023] A further feature of the mounting arrangement shown in FIGS. 6 and 7 allows for selective tilting of the arch. This is achieved by supporting the feet of the arch on the runners 32 by means of pins 38, which are selectively engaged with upper and lower locking holes 39 and 40 in the regions of the fore and aft edges of the arch. It will be appreciated that if both the fore and aft pins 38 are located in the lower holes 40, the arch will be helical. If the aft pin 38 is located in the upper hole 39 and the forward tilted forward. preferably by pin 38 in the lower hole 40, the arch will be approximately 10 degrees. Reversing the positions of the pins 38 will of course tilt the mast to the stern. Complete removal of the fore or aft pins 38 will allow the arch to be lowered to the aft or foredecks respectively.

[0024] In normal sailing conditions the sail is controlled by means of a control line 31 which extends from the rear of the bottom spar to the cockpit. By moving the carrier on its track around the arch, the sail can be pivoted through as much as plus or minus up to 90 degrees, and indeed can be placed horizontally when the vessel is at anchor.

[0025] As an alternative to the normal practice of reefing, in the present system, the sail can be leant into the wind by adjusting the carrier 17 to windward and the bottom line 19 to leeward under strong wind conditions. The sail is leant into the wind. This reduces the effective area of the sail, and also tends to lift the leeward hull, counteracting the tendency for the leeward hull to be driven deeper, a disadvantage of a Bermudan rig. As a consequence, the vessel can be sailed faster in heavy wind conditions. In even heavier winds, slackening the tension in the bottom line 19 will allow the sail to increase its curvature with the effect of reducing its power.