US3720180A

US3720180A - Raffe sail for boats

Info

Publication number: US3720180A
Application number: US00093084A
Authority: US
Inventors: P Stangeland
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-11-27
Filing date: 1970-11-27
Publication date: 1973-03-13
Anticipated expiration: 1990-03-13

Abstract

A sail for a boat rigged to present a horizontal rather than a vertical luff. The sail is triangular, one edge being attached to a yard which is supported from a mast in a horizontal position. The yard is formed as an air foil so that the horizontal luff produces a lifting force on the yard. One apex of the triangular sail is sheeted so that it bellies out with the upper part extending forwardly so that the wind pressure produces an upward thrust on an area of the sail tending to lift the bow of the boat.

Description

United States Patent 1 1 Stangeland 1March 13, 1973 1 1 RAFFE SAIL FOR BOATS 20,233 5/1858 Very ..114 104 [76] Inventor: Phillip F. Stahgeland, 121 I Wavecrest Avenue, Venice, Calif. Primary Exami"e'TrYgVe Bhx Attorney-Herzig & Walsh [22] Filed: Nov. 27, 1970 [21] Appl. No.: 93,084 ABSTRACT A sail for a boat rigged to present a horizontal rather [52] U.S.C1 ..114/102 7 h n a ver i al luff. The sail is triangular, one edge [51] Int. Cl. ..B63h 9/04 being attached to a yard which is supported from a [58] Field of Search....1 14/89, 90, 91, 102, 103, 104, mast in a horizontal position. The yard is formed as an 114/105, 39; 244/42 R air foil so that the horizontal luff produces a lifting force on the yard. One apex of the triangular sail is References Cited sheeted so that it bellies out with the upper part ex- UNITED STATES PATENTS tending forwardly so that the wind pressure produces 1 an upward thrust on an area of the sail tending to lift 3,066,894 12/1962 Davidson ..244/42 R the bow of the boat.

758,171 4/1904 Collins ...ll4/102 3,310,017 3/1967 Dyer ..114/102 X 3 Claims, 9 Drawing Figures RAFFE SAIL FOR BOATS SUMMARY OF THE INVENTION The invention relates to the construction of sails for sailing vessels and, more particularly, the rigging of the particular sail of the invention.

In the preferred form of the invention, the sail is triangular, one side edge being affixed to the trailing edge of a yard which is positioned horizontally to present a horizontal luff and further the yard being formed as an air foil to provide lifting effect on it. The yard is centered horizontally and supported at the top of the mast presenting the horizontal luff. Its clew located at one apex of the triangle is sheeted off the bow of the vessel.

While great advances have been made in the art of sails and rigging, the present state of the art is reflected in techniques of getting yachts to sail closer to the wind. The art is a story of the evolution of vertical luff sails. Vertical luff means that the leading edge of the sail with respect to the wind is vertical. Since ancient times, however, the principles of down wind sailing remain the same, that is, when the wind goes aft of the beam, the sails are trimmed square or perpendicular to the wind and the vessel under them as in ancienttimes still just gets pushed along. The limitations involved here derive from the fact that sails trimmed square to the wind as in the case of all downwind sailing today operate under stall. This means that as the wind pipes up or increases, wind vortexes swirl alternatingly from the sides of the stalledsail causing the boat under them to roll. This is especially noticeable in spinnakers which also by fulcrum effect, force the bow of the vessel downwards. The primary object of the invention is to provide a distinct improvement in sails for sailing and in the rigging of the sail whereby to cause the sail to produce an upward thrust on the bow of the boat; to thereby make steerage way easy and safe while avoiding accidental gybes and spinnaker knockdowns; and further to stabilize the vessel with respect to pitch and roll and to eliminate or minimize stall effect.

A further object is to provide a sail presenting a horizontal luff, the sail securedto a yard formed as an air foil to provide lift, the sail being triangular and having one apex thereof sheeted to the bow of a vessel.

A further object is to enable the improvements as defined herein to enable a vessel to sail at higher speeds, to improve stability and to sail more directly off i the wind.

BRIEF DESCRIPTION OF THE DRAWINGS Further objects and additional advantages of the invention will become apparent from the following detailed description wherein:

FIG. 1 is a bow view of the arrangement of the invention;

FIG. 2 is a view of the arrangement of the invention from abeam;

FIG. 3 is a perspective view of the improved sail and rigging of the invention;

FIG. 4, 4a, 4b and 4c are views of typical prior art sail rigs illustrating the stall effect and the tendency to pull the bow of the vessel into the water; and

FIGS. 5 and 5a are views illustrating the improved characteristics of the sail and rigging of the invention.

Referring more in detail to the various figures of the drawings, numeral 10 designates a vessel having the improved sail and rigging of the invention. Numeral 12 designates the mast of the vessel. Numeral 14 designates a yard rigged from the mast 12. Mast 12 is stayed by headstay l6 and backstay 18 and the outer edges of the yard are guyed by

guy lines

20 and 22. The vessel may be one having a hull of any type having typical construction as to characteristics such as amount of free board, gunwhales, bowsprit, stern, cockpit, decking, etc.

The yard 14 is formed as an air foil having a configuration as shown having a rounded leading upper edge and surface so as to create an air flow which produces a lifting force on the upper surface as in an airplane wing. In other words, the yard presents a horizontal luff. Sail 30 is triangular as shown. One straignt edge portion is suitably secured to the air foil 14. In the preferred form of the invention as shown, one apex 32 is sheeted to the bow of the vessel by a sheet 34.

Additional sails of typical construction may be provided or used as designated at 35 and 36 which are triangular sails rigged to the mast and having

booms

37 and 38. These sails may be sheeted and otherwise rigged conventionally.

FIGS. 4a, 4b and 4c illustrate typical prior art squaresail marconi sail, and spinnaker rigs, and the characteristic stall effects associated with them. FIG. 4 illustrates how such rigs tend to cause the bow of the vessel to be pulled down into the water.

FIGS. 5 and 5a illustrate the usage or operation of the improved sail and rigging of the invention. The apex 32 of the sail is sheeted so that the wind bellies it out as shown so that the upper part of the sail is extended forward so that there is a substantial surface area at the upper part of the sail which is generally horizontal as shown. The force of the wind thus produces an upward thrust or lifting force which when exerted through the sheet tends to lift the bow of the vessel as illustrated in FIG. 5. The effect produced, therefor, is easily understood. All of the objects as referred to in the foregoing are realized. Preferably at the ends of yard there are provided configurations as shown which act as spoilers which serve to prevent vortexes and eddy currents so that these devices add to the directional stability produced by the sail and its rigging. The pitch and roll characteristics of the vessel are improved by reason of minimization of the stall effect characteristic of known types of sails and the oscillation is reduced. Typical prior art sails, particularly spinnakers, fulcrumed at the top of the mast exert a force tending to pull the bow of the boat downwardly. This effect is eliminated and reversed in the sail and rigging of the herein invention. The tendency of the boat to flounder is thus eliminated or minimized. The effect further is that the boat can sail closer to the wind at higher speeds with the improved stability as described.

The foregoing disclosure is representative of a preferred form of invention and is to be interpreted in an illustrative rather than a limiting sense, the invention to be accorded the full scope of the claims appended hereto.

What is claimed is:

1. For use with a sailing vessel, a sail rigged to a mast, the sail being constructed and arranged to extend a substantial distance laterally and generally horizontally at the upper part of the sail, the lower part of the sail having sheeting means whereby to cause the sail to belly forwardly with an area at the upper part of the sail extending forwardly so that the wind pressure exerts an upward thrust on the sail causing the sheeting means to lift the bow of the vessel, said upper edge part of the sail being positioned to provide a horizontal luff, a laterally positioned yard to which the sail is secured,

extremeties of the yard to prevent vortexes and eddy currents.

3. A sailing rig, including a sail, as in claim 1, including additional conventional sails rigged to a mast.

Claims

1. For use with a sailing vessel, a sail rigged to a mast, the sail being constructed and arranged to extend a substantial distance laterally and generally horizontally at the upper part of the sail, the lower part of the sail having sheeting means whereby to cause the sail to belly forwardly with an area at the upper part of the sail extending forwardly so that the wind pressure exerts an upward thrust on the sail causing the sheeting means to lift the bow of the vessel, said upper edge part of the sail being positioned to provide a horizontal luff, a laterally positioned yard to which the sail is secured, the yard being supported from a mast, said yard being formed as an air foil whereby the horizontal luff provides a lifting force on the yard and the upper part of the sail.

2. A sail as in claim 1, including spoiler means at the extremeties of the yard to prevent vortexes and eddy currents.