Ships – Sail or control means therefor – Specific sail structure or arrangement
Patent
1986-09-11
1988-08-30
Basinger, Sherman D.
Ships
Sail or control means therefor
Specific sail structure or arrangement
114103, B63H 906
Patent
active
047668318
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
The present invention relates to rigging for a wind propelled craft.
The apparatus of the present invention will hereinafter be described with particular reference to wind propelled craft being sailing vessels, such as for example 18 foot skiffs, although it is to be understood that it is of general applicability.
FIELD OF THE INVENTION
In general, sails used to propel sailing vessels are either relatively thin, compared to their length, or comprise fixed symmetric aerofoils such as in recent international C class catamarans.
In the former case the sail creates forward drive by an aerofoil action produced by stagnation of air at the leach of the sail and at the mast on the windward side thereof. The stagnation leads to a net circulation of air about the sail. The drive produced by the sail is dependent upon the amount of circulation. Such sails are relatively inefficient since they are thin and can only create a small amount of circulation of air about the sail. In the latter case the portion of the sail which is the fixed symmetric aerofoil serves to increase the circulation of air about the sail. Thus, a part fixed symmetric aerofoil sail gains drive indirectly from the aerofoil. Similarly, drive can be produced by a sail formed of several fixed symmetric aerofoils pivotally attached at in line at their respective forward and trailing edges.
It has been found that an efficient sail can be formed from a single fixed aerofoil having a particular shape. The actual aerofoil shape is dependent upon the conditions of its use. However, a fixed asymmetric aerofoil is required. Thus, a sailing vessel having such a sail could only be operated on a port or a starboard board but not both.
SUMMARY OF THE INVENTION
The present invention provides rigging for a wind propelled craft employing an asymmetrical aerofoil sail which can be used to propel a vessel on both port and starboard boards.
In accordance with one aspect of the present invention there is provided rigging for a wind propelled craft, the rigging (a) characterised in that it comprises a flexible sail comprising two substantially identical flexible sail portions each having a leach and a luff, the flexible sail portion being arranged to give the flexible sail an effective thickness substantially greater than that of either of the flexible sail portions individually and a pocket means arranged to receive an elongated batten having flexure in at least two dimensions, the elongated batten comprising two substantially elongated batten portions each having a first free end and a second end, the second ends being arranged to be connected together adjacent the leach of the flexible sail portions, the elongated batten portions being splayed apart and extending toward the luff of the flexible sail portions, a spar connected to the luff of the flexible sail portions and having a control means to vary the thickness of the flexible sail such that the craft may be propelled by wind incident at various angles of attack to the spar.
In accordance with a further aspect of the present invention there is provided a flexible sail, characterised in that it comprises two substantially identical flexible sail portions arranged to give the flexible sail an effective thickness substantially greater than that of either of the flexible sail portions individually so that, in use, the flexible sail may be controlled by a rigging to conform to an asymmetric aerofoil shape.
In accordance with a still further aspect of the present invention there is provided an elongated batten, characterised in that it has flexure in at least two dimensions and comprises two substantially identical elongated batten portions each having a first free end and a second end, the second ends being arranged to be connected together and the elongated batten portions being splayed apart and extending in the same general direction towards their first ends, each of the elongated batten portions being arranged, in use, to be inserted into a pocket means of a flexible sail comprising two substanti
REFERENCES:
patent: 2107303 (1938-02-01), Ljungstrom
patent: 2561253 (1951-07-01), Wells-Coates
patent: 2569318 (1951-09-01), Kersten
patent: 3132620 (1964-05-01), Court
patent: 4064821 (1977-12-01), Roberts, Jr. et al.
patent: 4369726 (1983-01-01), Mader
patent: 4386574 (1983-06-01), Riolland
LandOfFree
Rigging for a wind propelled craft does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rigging for a wind propelled craft, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rigging for a wind propelled craft will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2081711