US20080127873A1

US20080127873A1 - Triangular boat sail

Info

Publication number: US20080127873A1
Application number: US11/975,580
Authority: US
Inventors: Nicolas Johansen
Original assignee: ELVSTROM SAILS (SARL)
Current assignee: ELVSTROM SAILS (SARL)
Priority date: 2006-11-28
Filing date: 2007-10-19
Publication date: 2008-06-05
Also published as: EP1927542A1

Abstract

A sail for a boat, and specifically a triangular sail (1). It comprises three extreme comers, head (10), clew (11) and tack (12), and three edges, a luff edge (15) linking the head point (10) to the tack point (12), a foot edge (13) linking the tack point to the clew point (11), and a leech edge (14) linking the head point (10) to the clew point (11), and furthermore, a regular succession of long battens (22) and short battens (23) parallel to the luff edge (15).

Description

The object of this invention is a sail for a boat, specifically a triangular sail.
It is known that in sailing, the surface of the boat's sail must be adapted to the force of the wind and for this purpose the navigator has furling rollers allowing reduction of the surface by furling when the wind blows; the sail must remain as flat as possible to retain maximum strength.
A triangular sail has three extreme points, the head, clew and tack corners, and three edges, the luff edge linking the head point to the tack point, the foot edge linking the tack point to the clew point, and the leech edge linking the head point to the clew point. The curvature of the leech defines the curve of the leech, which is zero when the leech is straight, negative when the leech is curved inward, and positive when the leech is curved towards the outside of the sail. When the curve of the leech is positive, the surface area of the sail is increased, which improves the performance of the sail and the additional surface is well-placed in the sail.
However, a positive sail curve causes flapping of the sail that reduces the energy of the wind on the latter and decreases the efficiency of the sail. Additionally, when the sail is furled, the central part has too large a belly.
To remedy this inconvenience, document FR67984 proposes a sail, adaptable to any roller, that allows a reduction of the surface of the sail while reducing the belly thanks to one or more battens, each placed in a sheath parallel to the luff, so that when the sail is furled, the battens artificially flatten it. Additionally, the battens hold the leech and prevent flapping of the sail.
However, the weight of battens installed along the full height of the sail decreases the stability of the boat and makes maneuvering difficult. Furthermore, the battens occupy a significant volume while furling the sail and the available volume on the mast is often limited, which imposes the use of a reduced number of battens.
The purpose of this invention is to remedy this inconvenience by offering a sail, and particularly a triangular sail that allows increased curvature of the leech without flapping of the sail and without generating problems of volume on furling.
The sail according to this invention presents a triangular shape with three extreme points, the head, clew and tack comers, and three edges, the luff edge linking the head point to the tack point, the foot edge linking the tack point to the clew point, and the leech edge linking the head point to the clew point, and includes a regular succession of long and short battens mounted parallel to the luff.
The long battens will completely or approximately link the leech to the foot while the short battens will be placed preferably at the upper part of the sail extending from the leech of the sail.
Additionally, the succession of long and short battens will be arranged with at least one short batten between two long battens. The sail will have, for example, a succession of two short battens located between two long battens.
Furthermore, to ensure the reliable mounting/effective interaction and protection of the long and short battens, these may be inserted, respectively, in the long and short sheaths sewn into the sail.

The advantages and the characteristics of this invention will become clearer in the description that follows and with reference to the attached drawings, which present a non-limitative method of execution.

FIG. 1 represents the front view of a triangular sail according to this invention.

FIG. 2 represents a schematic view of a sail with positive, zero, and negative leech curvature.

Referring to FIG. 1, one may see that the sail according to this invention presents a triangular shape with three extreme points, the head (10), clew (11) and tack (12) comers, and three edges, the luff edge (15) linking the head point (10) to the tack point (12), the foot edge (13) linking the tack point (12) to the clew point (11), and the leech edge (14) linking the head point (10) to the clew point (11).
The curvature of the leech defines the curve of the leech, which is zero when the leech (14) is straight, as can be seen in FIG. 2, negative when the leech is curved inward, and positive when the leech is curved towards the outside of the sail (1).
FIG. 1 shows that the sheaths (2) are sewn onto the sail (1) parallel to the luff (15) and regularly spaced, alternating long sheaths (20) and short sheaths (21).
Long battens (22) and short battens (23) are inserted in the sheaths (2) and allow the sail to be held in the wind, preventing its deformation with negative curvature of the leech.
The long battens (22) have a length equal to the height of the sail at their point of intersection and extend from the leech (14) to the foot (13), parallel to the luff (15); the length of each of the long battens (22) are arranged in decreasing order from the luff (15) to the leech (14) (or it could be: from the tack (12) to the clew (11) The function of the long battens (22) is, on one hand, to hold the sail to prevent negative curvature of the leech, and on the other hand, when furling the sail, to artificially flatten the latter and limit the creation of too large a belly.
It is noted that the length of the long battens (22) may be defined so that they extend completely or approximately from the leech (14) to the foot (13); that is, in the latter case, leaving a space between the free ends of the long battens (22) and the edges (13), (14) of the sail, without affecting the function of the long battens.
The short battens (23) are of a lower length than the long battens (22) and each short batten (23) extends between two long battens (22) from the leech (14), parallel to the long battens (22). The short battens (23) will preferably all be of the same length.
The addition of at least one short batten (23) between two long battens (22) allows reduction of the overall weight of the battens and the retention of a sufficient number of battens to obtain a positive or zero leech curvature, without, however, generating problems with volume on furling.
Furthermore, it may be seen that the short battens (23) are placed on the upper part of the sail; that is, in an area where the volume is less significant on furling.
A sail designed according to this invention presents a surface nearly identical to that of a sail without a furling roller and can be used as a mainsail with pole roller, preventing, in contrast to classic mainsails with pole rollers, the formation of a negative leech curvature while limiting the volume of the sail on furling.

Claims

1) A sail for a boat, and specifically a triangular forward sail (1) with three extreme corners, head (10), clew (11) and tack (12), and three edges, a luff edge (15) linking the head point (10) to the tack point (12), a foot edge (13) linking the tack point to the clew point (11), and a leech edge (14) linking the head (10) to the clew point (11), characterized by its inclusion of a regular succession of long battens (22) and short battens (23) parallel to the luff edge (15).

2) A sail according to claim 1 characterized by its long battens (22) extending completely or approximately from the leech (14) to the foot (13).

3) A sail according to claim 1 or claim 2 characterized by its short battens (23) being placed on the upper part of the sail, extending from the leech (14) of the sail (1) linking the head (10) to the clew (11).

4) A sail according to any of the claims above characterized by the succession of long battens (22) and short battens (23) being distributed with at least one short batten (23) between two long battens (22).

5) A sail according to claim 4 characterized by including a series of two short battens (23) between two long battens (22).

6) A sail according to any of the above claims characterized by the succession of long battens (22) and short battens (23) being inserted, respectively, into long sheaths (20) and short sheaths (21).