GB2210010A - Boat having a thick sail directionally adjustable in accordance with three axes - Google Patents

Abstract

The sailing boat according to the invention is of the type comprising at least one bearing mast 106, to the top of which a thick-sail structure 108 is fixed, that is to say an essentially rigid structure having a rounded leading edge 109, a trailing edge 112, marginal edges 110 and 111, a convex outer surface 114 and an inner surface, this structure 108 being mounted in an orientable manner in relation to the bearing mast 106. It is characterised in that the bearing mast 106 is fixed and in that the structure 108 is connected to it by means allowing relative orientation of the bearing mast 106 and of the structure 108 along three orthogonal axes. <IMAGE>

Description

BOAT HAVING A THICL: SAIL DIRECTIONALLY ADJUSTABLE IN ACCORDANCE WITH THREE AXES It has long been known that one of the parameters contrary to achieve a good efficiency for a sailing boat based on a given wind, is the flexibility of the sails. In effect, these yield to the thrust of the wind and assume a concave shape, thus absorbing a part of the energy imparted by the wind.

To remedy this disadvantage, it has already been envisaged that rigid and "thick" sails of a design transposed directly from that of aircraft wings can be used.

The patent FR-A-1,484,739 thus describes a sailing boat having a mast which is pivotally mounted at its base and at its top carries a radial carrying arm on which is pivotally mounted a yard carrying the sail on one of its sides. The incidence of the sail plane may be altered by means of control mechanism.

It is apparent that to set the sail plane correctly whilst allowing for the wind direction and force as well as for the desired course, it is necessary c act on three different and mutually independent controls a crank placed close to the deck has to ce tilisd to cause the mast to pivot, ropes called "sheets", fastened to the extremity of the lever, which is eccen~r- ically positioned with respect to the said carrier arm, to provide a rocking torquf, have to be utilised to cause the sail plane to pivot around the axis of the carrier arm, and a third mechanism intended to cause the pivoting of the sail plane around the third axis has to be acted upon to cause the incidence to vary.

This structure is thus rather awkward and does not render it possible to provide the sail quickly and easily with all the possible orientations for optimum utilisation of the wind force irrespective of cruising conditions. Furthermore, all these separate axes associated with different mechanisms are as much causes of weakness and of seizures, particularly in the arduous working conditions established by a marine environment ; salt deposits, corrosion, oxidisation, etc.

The present invention provides a completely new solution for the construction of boats having sails of the thick and rigid type.

To this end, the invention provides a sailing boat of the kind comprising at least one carrying mast, to the top of which is attached a thick sail structure, that is to say one which is substantially rigid and has a rounded leading edge or luff, â trail ing edge or leech, lateral edges, a convex outer surface and an inner surface, the structure beIng mounted in a directionally adjustable manner with respect to the said carrying mast, wherein the said carrying mast is stationary and the structure is connected to the same by means permitting relative orientation of the carrying mast and the said structure in accordance with three orthogonal axes.

According to other features of the invention: - the said structure has a fastening element referred to as a clew for a rope,called "sheet",which has to be acted upon to cause certain orientations of the structure, this clew being situated on the axis of the structure, between the means of connection to the carrying mast and the trailing edge, and in that the sheet is run from this clew to an element such as a pulley which is attached to the same boat and referred to as a "traction point", which is advantageously adjustable in height, situated on the axis behind the carrying mast and capable of being positioned substantially at the same level as the said connecting means; - each lateral edge has fastening means for rope referred to as a "yardarm" which has to be acted upon to achieve certain orientations of the structure;; - the boat comprises a second mast situated on the axis and behind the carrying mast, the traction point being connected to this second mast; - the two masts are joined together in their upper portions b a rigid longitudinal beam; - the structure comprises an internal framework and external sail elements, the framework comprising at least one beam bearing a lateral edge at each cf its two extremities, and ribs at right angles to the beam(s), a central rib of which is secured to the beam(s) and carries means of connection to the carrying mast:: - the ribs of the framework situated between the central rib and the lateral edges are movably arranged with respect to the beam(s) and at least some of these movable ribs are provided with handling means intended to displace these along the beam or beams, either in the direction of the lateral edges towards the centre rib or in the opposite direction;; - the handling means are formed by ropes referred to as yard-ropes or brails, each having one of its extremities fastened to a movable rib, being associated with returning means such as pulleys, situated on the central rib, and passing through at least one sail element via a passage formed for this purpose as close as possible to the carrying mast to end close to the boat deck, within easy reach, - the lateral edges each bear at least one returning pulley for at least one so-called yard rope or brail threaded through the same, this pulley dividing two sections of the yard rope, one of which is secured to the movable rib closest to the corresponding lateral edge, and the other of which extends parallel to the beams as far as a return element such as a pulley situated on the central rib, and passes through at least one said element via a passage formed for this purpose as close as possible to the carrying mast to end within easy reach, close to the boat deck.

The invention will now be further described b way of example only with reference to the accompanying drawings, wherein Figure 1 is a schematic view of the stern cf a catamaran according to the invention, Figure 2 is a schematic perspective view of this catamaran sailing close-haule on the starboard tack, Figure 3 is a schematic view of the stern of the catamaran sailing slack on the starbard tack, Figure 4 is a schematic view in perspective of the catamaran sailing slack on the port tack, Figure 5 is a schematic perspective view showing a particular form of embodiment of the connection between the internal framework of the sail structure and the top of the carrying mast, Figure 6 is a partial schematic view showing a detail of a form of embodiment according to which the framework comprises movable ribs, Figure 7 is a schematic view of the whole of the internal framework of the sail structure produced with movable ribs, Figure 8 is a plan view from the inner side of the sail structure as it appears with its sail elements, Figure 9 is a plan view of the same sail structure as that of Figure 8, after special displacement of the ribs such that the sail elements situated to either side of the central rib are folded back, which commensurately reduces the sail surface available to the wind, Figure 10 is a plan view of the same structure as that of Figures 8 and 9 after special displacement of the movable ribs so that the sail elements are all folded back, except for those which are situated closest te the lateral edges, the sail surface being reduced in a very appreciable manner, Figures 11, 12 and 13 are three schematic views of the stern of the catamaran sailing close-hauled on the port tack with a sail unit set up in accordance with Figures 8, 9 and 10, respectively, The example of a catamaran was selected to illustrate the invention but it should be understood that the invention is applicable to all kinds of boats : single or multi-hulled, small sports boats, large cruisers, or even work boats.

An embodiment of the invention will similarly be described for a single-masted boat and a single sail structure, but the invention could, in practice, be applied to boats comprising several masts.

Referring to Figures 1 to 4, a sailing boat is shown which consists of a catamaran 100 comprising two hulls or floats 101 and 102, two cross-beams 103 and 104 as well as a deck 105.

A carrying mast 106 is secured to the boat by any known means and at its tip comprises means 107 for its connection to a sail structure 108.

The structure 108 comprises an internal framework which will be described in particular in the following, and sail elements stretched over this framework.

The framework gives the structure a degree of rigidity and thickness rendering the same streamlined and liable to incur little or no warping under the action of the wind. The structure has the form of a double aircraft wing with respect to a symmetry axis A and has a leading edge or luff 109, lateral edges 110 and 111,as well as a trailing edge or leech 112, the rounded off leading edge tapering from the axis A to the lateral edges 110 and 111. The inner surface 113 faces towards the carrying mast 106 and the outer surface 114 consequently faces away from the same.

The means 107 may be of different kinds provided they allow a relative displacement between the carrying mast 106 and the structure 108 in accordance with three orthogonal axes. A description will be given in the following with reference to Figure 5 of an embodiment providing combined mechanical members, but this could comprise a single elastically deformable element, such as a component of elastomeric material, a spring and other equivalents.

Each lateral edge 110 and 111 has secured to it the extremity of a rope known as "yardarm" 120 and 121 respectively, leading to a returning element such as a pulley 122 and 123 respectively, which are integral with the boat, each being referred to as a traction point since upon pulling on one of these ropes 120 and 121, the pulling force applies a component on the corresponding pulley.

These ropes 120 and 121 are certainly yardarms, since the internal framework of the structure 108 gives the same rigidity transversally to the boat, which enables the framework to be likened to a conventional yardarm, and the fastening of these handling ropes to the extremities 110 and 111 of the yard actually gives them the inherent directional function of a yardarm.

In Figure 1, the structure 108 is substantially horizontal, the yardarms 120 and 121 both having an identical extension. The structure is thus in the idle position, for example, head into wind upon turning. It is sufficient to free (ease off) one of the yardarms and to pull on the other to achieve the orientation of the structure 108 either towards starboard (sailing on the port tack) or towards port (sailing on the starboard tack).

Each yardarm 120 and 121 may be single and its free extremity is intended to be fastened ("struck") on a fixed element such as a cleat to attach the same.

The two yardarms may also be formed with a single rope reeved through the two pulleys 122 and 123 and one extremity of which is secured to the lateral edge 110 whereas the other is secured to the lateral edge 111.

The yardarms 120 and 121 are then formed by the two sections of the same rope as illustrated. The part 124 of the rope situated between the two pulleys 122 and 123 is common to both yardarms and may be used to immobilise the arms 120 and 121 in the relative position selected, for example by means of a central cleat 125 (Figure 2).

According to an important feature of the invention, the structure 108 has a "clew" situated within its outline on the inner side 113. The term "clew" is applied to the point at which the sail receives the extremity of a rope intended for handling the same (and for tensioning the same in the case of conventional sails) and which is referred to as the "sheet".

According to the invention, this point 130 (Figures 3 and 8) is situated on the axis A between the point at which the carrying mast 106 should be positioned and the trailing edge 112. It is also placed aft of the "centre of effort" of the sail (point of application of the resultant of the forces exerted on the said structure 108 by the wind) which is equally situated aft of the carrying mast 106.

As a matter of fact, this clew may be formed by a ring fastened to the internal framework and passing through the outer sail skin, the clew ending in a manner known per se in a loop or eye which is joined to the ring by a shackle.

Due to these arrangements, the action of the wind always exercises a moment on the structure 108 which tends to pivot the same about connecting means 107, whilst moving the trailing edge 112 away from the boat.

A single clew situated at the point 130 is thus adequate to control the structure 108 since the same is constantly impelled in the opposite direction to that of the pull exercised on the clew.

According to another important feature of the invention, the point of traction of the clew should be positioned at the same level as the connecting means 107.

To this end, a second mast 131 should be provided aft of the carrying mast 106 and the top of this second mast 131 should have fastened to it a returning element such as a pulley 132 for a clew 133 which extends along the mast 131 and down to the deck within reach of a hand, where it may be fastened by means of a cleat 134.

The aim pursued is to permit the clew 133 to extend from the clew point 130 to the traction point 132, whilst being in a plane which is substantially perpendicular to the centre line connecting the lateral edges 110 and 111. The position of the clew point being established b the sailing conditions, it is the traction point which may be made to be adjustable. For example, the pulley 132 may be placed on a slider displaceable along the mast 131. As known per se, this mounting may be achieved by providing a guiding rail along the mast 131 and securing the pulley 132 on a slider provided with a blocking device (not shown). In Figures 1 and 4, the pulley 132 is at the top of the mast 131, whereas in Figure 3 it is in a position at approximately half height.

For the purpose of overall rigidity, it is advisable for the two masts 106 and 131 to be joined together at their upper parts by means of a rigid beam 135 (Figure 4). Furthermore, this arrangement has the advantage of eliminating the pointed nature of the top of the mast 131 which consequently no longer raises the risk of slashing the structure 108 in the case of a down wind which could cause the same to be flung downwards accidentally.

Referring to Figures 5 to 10, it is apparent that the structure 108 comprises an internal framework 140 formed by a beam 141 having its extremities attached to the lateral edges 110 and 111, by a central rib 142 fastened to the middle of the beam 141 and at right angles to the same, and by movable ribs 143 to 150 capable of being displaced along the stationary beam 141. Each movable rib 143 and 150 has fastened to it two ropes which are substantially parallel to the beam 141 and situated at either side of the same, marked 160 to 167 and 170 to 177, respectively. The ropes 160 to 165 and 170 to 175 are "brails". They are reeved over return pulleys 180 and 181 situated on the central rib 142 and then run along the carrying mast 106 to within easy reach. The ropes other than 160-170 and 161-171 pass through wide passages 190 and 191 (Figure 6) in the rib or ribs situated between the central rib 142 and the rib to which they are attached.

The ropes 166-176 and 167-177 are yard ropes.

They pass through all the ribs other than the central rib 142, via the passages 190 and 191. They are reeved through pulleys 152 and 153 situated in recesses 194 and 195 of the lateral edges 110 and 111, and which divide them into two sections 166,166a, 176,176a, 167,167a and 177,177a.

The sail unit as such comprises elements or sheaths 201 to 208 which wholly enclose the framework 140. Each element has a width such that it may be secured on two adjacent ribs. They are evidently dimensioned to fit as closely as possible on the ribs and to form as perfect as possible an uninterrupted surface. They play a part in giving the leading edge 109,as seen in plan view (Figures 2 and 8) a preferably ellipsoidal regular curved line. The same applies to the trailing edge 112, although the radius of curvature of the leading edge 109 is smaller than that of the trailing edge 112, since the leading edge 109 works more than the trailing edge 112. According to the example illustrated, the trailing edge 112 is formed by two interrupted arcuate curvatures increasing the sail surface in the median portion. This ellipsoidal form achieves an optimum aerodynamic efficiency.

If the said structure 108 is intended to provide a maximum surface, as illustrated in Figures 1 to 4, 8 and 11, the yard ropes 166-176 and 167-177 are tensioned. The movable ribs 149 and 150 are practically applied against the lateral edges 110 and 111 as apparent from Figure 7.

If the sail area is to be reduced staking in a reef"), the yard ropes 166-176 and 167-177 are slackened and the brails 160-170 or 170,171 or both, are heaved on. Either the rib 144 by itself, or the rib 143 bp itself, or both at the same time, is/are thereby brought closer to the central rib 143. It is this assumption which has been deduced and illustrated in Figures 9 and 12. The sail elements 201 and 202 are thereby caused to bend. The yard ropes 166-176 and 167-177 are tightened again and the structure 108 is placed in the condition of Figures 9 and 12. Its surface is reduced because the sail elements 201 and 202 are neutralised and also because these elements are the most extensive.

If it is intended to take in another reef, that is to say if the sail area is to be reduced further, the yard ropes 166-176 are eased off and the brails 162-172 and/or 163-173 are tightened. The ribs 143 and 144 which had already been moved towards the central rib 142 thereby have the ribs 145 and 146 brought closer to them, thus forcing the said elements 203 and 204 to bend. The sail area may be shortened further by acting as stated for the ribs 147 and 148, which leaves only the sail elements 207 and 208 undisturbed, as shown in Figures 10 and 13. This condition is adopted in the case of very strong winds, to retain no more than a very small sail area, since the only to remaining elements 207 and 208 are also the smallest.

It is evidently also possible to fold the sail elements 207 and 208, in which case the remaining area is practically zero. This condition may be that with the boat stopped "riding at anchor". As a result, it is possible to leave the structure 108 in position.

It will be observed that the said area may be shortened either at one side only of the central rib 142, or at both sides and this either symmetrically or not. Numerous possibilities are thus available for adaptation of the structure in respect of orientation as well as of surface.

These arrangements are particularly advantageous since the reduction and increase of the sail area symmetrically to either side of the central rib 142 do not alter the location of the pressure centre of the sail and have practically no repercussion on the adjustment of the clew 133. This results in great stability of the boat and very smooth sailing.

The sail elements 201 and 202 comprise passages 211 and 212,through which are intended to pass the yard ropes 166-176 and 167-177 as well as the brails 160-175. Given that the structure 108 can assume orientation of very great amplitude with respect to the carrying mast 106, the passages 211 and 212 should be placed as close as possible to this mast 106.

The folding of the sail elements 201 and 202 has practically no effect on the ease of displacement of the rigging, since these elements 201 and 202 are very pliable when unstressed and there is no need to fear any risk of jamming.

To restore a greater surface to the structure 108, that is to say for example to change from the condition of Figure 10 to that of Figure 8, the brails are slackened and the yard ropes 166-176 and 167-177 are tightened. The sections 166a,176a,167a and 177a pull on the ribs 149 and 150, these pull on the sail elements 207 and 208 which upon being tensioned exert a pull for their part on the ribs 147 and 148 which pull on the sail elements 205 and 206, and so on. The tensioning of all these sail elements, and consequently of the whole of the structure 108, is assured by the fact that the yard ropes 166-176 and 167-177 are hauled taut.

Referring to Figure 5, this shows an embodiment of the connecting means 107. The top of the carrying mast 106 is covered by a bell 300 held fast on the mast 106 by elements of any known kind (not shown). The bell 300 which has a kind of yoke, the arms 301 of which are joined together by a removable pin 302 engage in a swivel 303 secured to a slider 304 co-operating with a guiding rail 305 integral with an angle iron 306 fastened on the lower edge of the central rib 142. In this manner, this angle iron receives the pulleys 181.

In this arrangement, the assembly comprising the swivel 303, the slider 304, the rail 305, the angle iron 306 and the centre rib 142, and consequently the structure 108 as a whole, may pivot around the pin 302, that is to say around the longitudinal axis of the boat. It may also slope towards the bow or towards the stern, since the swivel may be engaged at the top of the arms 301. The assembly comprising the structure 108, the angle iron 306 and the rail 305 may slide from front to back with respect to the slider 304 so that the structure 108 may naturally assume the most advantageous position with respect to the carrying mast 106, depending on the manner in which the sail is set up.

The deflection of the structure 108 with respect to the axis of the carrying mast 106 is rendered possible by the play present between the outer diameter of the pin 302 and the inner diameter of the swivel 303. This deflection occurs within a comparatively substantial angular amplitude and allowing for the length of the beam 141, this amplitude corresponds to a displacement of the extremities (lateral edges 110 and 111) which is ample in respect of the practical requirements of sailing.This degree of freedom is of considerable interest because, in the case of Figure 3 for example, the lowest extremity of the structure of the sail (being the lateral edge 110 in this case) tends to move forward and the upper extremity (lateral edge 111) tends to move aft since this movement is needed for the structure 108 to be placed in the winds eye with the leading edge 109 perpendicular to the direction of the wind. The mounting according to the invention consequently enables the structure 108 to assume the optimum orientation with respect to three orthogonal axes, by acting on no more than the braces 120-121 and on the clew 133.

Depending on the manner in which the sail structure 108 is set up, what is obtained is not only a very effective wind thrust in the direction of the course of the boat but also a vertical component which tends to lighten the boat, to reduce its sinking in the water, to enable the same to cut more easily through the surface of the water, and thereby to improve its efficiency and its top speed, whilst improving the sailing conditions.

Claims (10)

1. A sailing boat of the kind comprising at least one carrying mast, to the top of which is attached a thick sail structure, that is to say which is substantially rigid and has a rounded leading edge or luff,a trailing edge or leech, lateral edges, a convex outer surface and an inner surface, the structure being mounted in a directionally adjustable manner with respect to the said carrying mast, wherein the said carrying mast is stationary and the structure is connected to the same by means permitting relative orientation between the carrying mast and the said structure in accordance with three orthogonal axes.

2. A sailing boat according to claim 1, wherein the structure has a fastening element referred to as a "clew" for a rope called a "sheet", which is acted upon to cause certain orientations of the structure, this clew being situated on the axis of the structure between the means of connection to the carrying mast and the trailing edge, and in that the sheet is run from this clew to an element such as a pulley attached to the same boat and referred to as a "traction point which is advantageously adjustable in height, situated on the axis behind the carrying mast and capable of being positioned substantially at the same level as the said connecting means.

3. A sailing boat according to claim 1 or 2, wherein each lateral edge comprises fastening means for a rope referred to as a "yardarm", which is acted upon to cause certain orientations of the structure.

4. A sailing boat according to claim 2 or 3, wherein it comprises a second mast situated on the axis and behind the carrying mast, the traction point being connected to this second mast.

5. A sailing boat according to claim 4, wherein the two masts are joined together at their upper portions by a rigid beam.

6. A sailing boat according toany preceding claim, wherein the structure comprises an internal framework and external sail elements, the framework comprising at least one beam bearing a lateral edge at each of its two extremities, and ribs at right angles to the beam(s), a central rib of which is secured to the beam(s) and carries means for connection to the carrying mast.

7. A sailing boat according to claim 6, wherein the ribs of the framework situated between the centre rib and the lateral edges are arranged to be moveable with respect to the beam(s) and at least some of these movable ribs are provided with handling means intended to displace them along the beam or beams either in the direction of the lateral edges towards the centre rib or in the opposite direction.

8. A sailing boat according to claim 7, wherein the handling means are formed by so-called "yard ropes" or "brails" fastened via one of their extremities to a movable rib, associated with returning means such as pulleys situated on the centre rib and passing through at least one sail element via a passage formed for this purpose as close as possible to the carrying mast to end within reach close to the boat deck.

9. A sailing boat according to claim 7 or 8, wherein the lateral edges each bear at least one returning pulley for at least one yard rope which is reeved through the same, this pulley dividing two sections of the yard rope, one of which is secured to the movable rib which is closest to the corresponding lateral edge and the other of which extends parallel to the beam(s) up to a returning element such as a pulley situated on the centre rib and passes through at least one sail element via a passage formed for this purpose as close as possible to the carrying mast to end within each reach close to the deck of the boat.

10. A sailing boat of the kind comprising at least one carrying mast, said sailing boat being substantially as herein described with reference to the accompanying drawings.