Water craft sail assembly and water craft comprising same

Abstract

The invention relates to a sail assembly (80) for a watercraft comprising a deck, the sail assembly comprising: - a mast (81) which is mounted at an incline with respect to the deck of the craft on a motorised shaft having an axis of rotation which is inclined with respect to the deck of the craft; - a plurality of spars (85) mounted at an incline with respect to the mast on either side of the mast; - between the ends of two consecutive spars located on the same side of the mast, a sail (83) and motorised means for deploying and folding this sail. Embodiments of the present application disclose at least one sail comprising a rigid upstream half-sail (83) and a rigid downstream half-sail (82) which are connected together by a hinge (86) mounted between the two ends of the consecutive spars (85).

Description

[0001] WATERCRAFT SAIL AND WATERCRAFT COMPRISING IT

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The present invention relates to a sail of a nautical vessel and a nautical vessel comprising it. It applies, in particular, to the field of sailing navigation of a merchant ship.

[0004] STATE OF THE ART

[0005] Sailing ship projects to reduce CO2 production all depend on a very simple equation allowing the quantification of the aerodynamic force developed by a sail:

[0006] F = 0.5*p*s* v 2 *Coefficient

[0007] Formula in which:

[0008] F is the force expressed in Newtons,

[0009] P is the density of air,

[0010] S is the surface area of ​​the sail,

[0011] V is the apparent wind speed, and

[0012] Coef is the efficiency coefficient depending on the shape of the roughness elongation, the Reynolds number etc.

[0013] Some projects seek to increase the sail's lift and reduce its drag by using thick profiles (like airplane wings). Other projects, to increase aerodynamic force, play on speed by seeking wind at altitude or by artificially creating excess speed by rotating the cylinder.

[0014] The lift coefficient generated by an asymmetrical thick profile peaks at around 1.7.

[0015] A thick symmetrical profile requires twice as much material as a thin profile, for example a soft sail, which will have a roughly similar lift coefficient, between 1 and 1.2. The relative reduction in drag with a thick profile will be a major advantage for configurations in which the apparent wind angle is very close to the sailboat's course (racing multihull or cargo ship using the sail as an aid). The wind speed at 200 m altitude is 50% higher than on the ground, because of the square of the speed we can expect to double the propulsive force for an equal surface area. It is enough to stabilize a kite with a surface area of ​​several hundred square meters.

[0016] However, none of the sails described above meet all the qualities necessary for a rig for a merchant ship:

[0017] - a large surface area, because the average wind is relatively weak,

[0018] - easy reduction of the surface area, because the wind can be strong or very strong,

[0019] - a limited air draft, the air draft being the total height of the rigging, - profiles efficient at low Rn, i.e. in light air,

[0020] - good resistance in strong winds,

[0021] - a small footprint on deck, to facilitate port operations,

[0022] - complete automation, so as not to affect the number of crew members,

[0023] - good erasure capacity, i.e. being able to feather very quickly with minimal resistance,

[0024] - be inexpensive and

[0025] - be sustainable.

[0026] Japanese utility model JP S60 110098 U is known, which discloses a boat whose rigid sail comprises three half-sails, together forming an arc of a circle, positioned at the top of a rotating mast. However, these three half-sails only form a sail positioned on one side of the mast.

[0027] Chinese patent application CN 104 176 222 A is known, which discloses a sail consisting of three rigid sails sliding along a mast. However, these three sails are positioned on the same side of the mast.

[0028] German patent application DE 37 18 414 A1 is known, which discloses a flexible sail whose sails are superimposed one under the other and fixed along the entire length of the spars. Similarly, the sails are mounted on one side of the mast only.

[0029] US patent US 2021 / 163112 A1 is known, which discloses a rigid sail comprising five sails stacked on top of each other. These five sails form a single large sail positioned on one side of the mast.

[0030] SUMMARY OF THE INVENTION

[0031] The present invention proposes, with at least one biplane wing, to obtain all or part of the qualities listed above.

[0032] BRIEF DESCRIPTION OF THE FIGURES

[0033] Other advantages, aims and particular characteristics of the invention will emerge from the following non-limiting description of at least one particular embodiment of the wing which is the subject of the present invention, with reference to the appended drawings, in which:

[0034] - Figure 1 represents, schematically and in perspective, the general inventive concept of the invention,

[0035] - figure 2 represents, schematically and in top view, a first particular embodiment of the wing which is the subject of the invention,

[0036] - figure 3 represents, schematically and in perspective, the wing illustrated in figure 2, partially deployed and partially folded, - figure 4 represents, schematically and in perspective, a second particular embodiment of the wing which is the subject of the invention partially deployed and partially folded,

[0037] - figure 5 represents, schematically and in side view, a first particular embodiment of a boat which is the subject of the invention,

[0038] - figure 6 represents, schematically and in top view, different speeds of a second particular embodiment of a boat which is the subject of the invention, all sails deployed,

[0039] - figure 7 represents, schematically and in side view, a third particular embodiment of a boat which is the subject of the invention, with sails partially deployed and partially folded,

[0040] - figure 8 represents, schematically and in top view, the boat illustrated in figure 5, the masts being pivoted to clear the deck of the boat,

[0041] - figure 9 represents, schematically and in perspective, a third particular embodiment of the wing which is the subject of the invention partially deployed and partially folded,

[0042] - figure 10 represents, schematically and in top view, a mechanism for deploying and folding the wing illustrated in figure 9,

[0043] - figure 11 represents, schematically and in top view, different speeds of a fourth particular embodiment of a boat which is the subject of the invention, all sails deployed,

[0044] - figure 12 represents, schematically and in side view, a fifth particular embodiment of a boat which is the subject of the invention,

[0045] - figure 13 represents, schematically and in top view, a third particular embodiment of the wing illustrated in figure 9,

[0046] - figure 14 represents, schematically and in top view, different speeds of a sixth particular embodiment of a boat which is the subject of the invention, all sails deployed and

[0047] - figure 15 represents, schematically and in top view, the sail illustrated in figure 2, with sails deployed in various ways.

[0048] STATEMENT OF THE INVENTION

[0049] The present invention aims to remedy all or part of the drawbacks of the prior art. To this end, according to a first aspect, the present invention aims at a biplane wing of a nautical vessel comprising a deck, which comprises:

[0050] - a mast, extending along an axis, mounted inclined relative to the deck of the boat, on a motorized shaft with an axis of rotation inclined relative to the deck of the boat,

[0051] - a plurality of spars mounted inclined relative to the mast, on either side of the mast, - for each side of the mast, between the ends of two successive spars located on the same side of the mast, a sail and motorized means for deploying and folding this sail.

[0052] These arrangements provide a low-draft biplane sail. In addition, the motorized rotation of each mast allows the position of the sails to be adapted to the speed of the boat.

[0053] In addition, a biplane wing or one with a small angle of incidence between its two sails of the same spar (for example 15°) has better lift and does not stall in the wind.

[0054] In embodiments, the sail comprises a yard at each end of each spar, each yard extending along an axis perpendicular to the axis of the mast, each sail being flexible and mounted between two parallel yards, the yards on one side of the mast being parallel to each other.

[0055] Thanks to these provisions, flexible sails, at lower cost, can be implemented.

[0056] In embodiments, the axis of a yard on one side of the mast is parallel to the axis of a yard on the other side of the mast.

[0057] In embodiments, the axis of a yard on one side of the mast intersects the axis of a yard on the other side of the mast. In embodiments, the sail comprises, for each flexible sail, a retaining rope between the yards surrounding the sail, this rope being positioned to windward of the yards and the motorized means for deploying and folding this sail comprises a sail furler consisting of a cylindrical tube rotating around a fixed cable, the sail being associated with the furler by a rope passing through a groove in the furler.

[0058] Thanks to these provisions, the deployment of the sails can be motorized.

[0059] In embodiments, the sail comprises two parallel masts jointly carrying the spars.

[0060] In embodiments, at least one sail comprises a rigid upstream half-sail and a rigid downstream half-sail connected to each other by a hinge mounted between two ends of successive spars.

[0061] In embodiments, the half-sails on one side of a spar have the same orientation as the half-sails on the other side of that spar.

[0062] In embodiments, the half-sails on one side of a spar have a different orientation than the half-sails on the other side of that spar.

[0063] Thanks to these arrangements, the sail can be folded or deployed by rotating one half-sail relative to the hinge common to the other half-sail.

[0064] In embodiments, each half-sail is a parabola arc.

[0065] Thanks to these arrangements, the shape of the deployed sail corresponds substantially to that of a flexible sail catching the wind. In embodiments, for each rigid sail, the motorized means for deploying and folding this sail comprises a jack.

[0066] In embodiments, the sail comprises a means for controlling the motorized means for deploying and folding an upstream half-sail relative to the downstream half-sail, this control means being configured to fold the half-sails onto each other when tacking and gybing and to reverse the curvature between starboard and port tack.

[0067] According to a second aspect, the present invention relates to a nautical vessel comprising at least one sail according to the invention.

[0068] In embodiments, the nautical vessel comprises a sail according to the invention around a foremast and a sail according to the invention around a mizzenmast.

[0069] DETAILED DESCRIPTION

[0070] This description is given without limitation, each characteristic of an embodiment being able to be combined with any other characteristic of any other embodiment in an advantageous manner. It should be noted from now on that the figures are not to scale.

[0071] As understood from the present description, various inventive concepts may be implemented by one or more methods or devices described below, several examples of which are provided herein. The actions or steps performed in carrying out the method or device may be ordered in any suitable manner. Accordingly, it is possible to construct embodiments in which the actions or steps are performed in a different order than illustrated, which may include performing certain acts simultaneously, even if they are presented as sequential acts in the illustrated embodiments.

[0072] The expression "and / or", as used herein and in the claims, is to be understood to mean "either or both" of the elements so conjoined, i.e., elements which are present conjunctively in some cases and disjunctively in other cases. Multiple elements listed with "and / or" are to be interpreted in the same way, i.e., "one or more" of the elements so conjoined. Other elements may optionally be present, other than the elements specifically identified by the "and / or" clause, whether or not they are related to these specifically identified elements.Thus, by way of non-limiting example, a reference to "A and / or B", when used in conjunction with open language such as "comprising" may refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0073] As used in this specification and in the claims, the expression "at least one", with reference to a list of one or more elements, is to be understood to mean at least one element selected from one or more elements in the list of elements, but not necessarily including at least one of each element specifically listed in the list of elements and not excluding every combination of elements in the list of elements. This definition also allows for the optional presence of elements other than the specifically identified elements in the list of elements to which the expression "at least one" refers, whether or not related to those specifically identified elements.Thus, by way of non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B", or, equivalently, "at least one of A and / or B") may refer, in one embodiment, to at least one, optionally including more than one, A, without B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, without A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0074] In the claims, as well as in the description below, all transitional expressions such as "comprising", "including", "carrying", "having", "containing", "involving", "holding", "consisting of", and the like, are to be understood as open, i.e., as meaning including, but not limited to. Only the transitional expressions "consisting of" and "consisting essentially of" are to be understood as closed or semi-closed transitional expressions, respectively.

[0075] In Figure 1, we see a sail 20 of a nautical vessel (not shown) comprising a deck 24. This sail 20 comprises a mast 21 mounted inclined relative to the deck 24 of the vessel, on a motorized shaft (not shown) with an axis of rotation 25 inclined relative to the deck of the vessel. Generally, the mast and the axis of rotation 25 are vertical, but, in variants, they are oblique. The axis of the shaft generally corresponds to the axis of the mast 21. The sail 20 also comprises a plurality of spars (not shown) mounted inclined relative to the mast 21, on either side of the mast 21. The sail 20 comprises, on each side of the mast 21, at least one sail 22 and 23 and motorized means for deploying and folding this sail (not shown). For example, furlers (not shown) are positioned at the windward end of the yards, 34 and / or 36, and allow the flexible sails 32 and 33 to be deployed or folded.The sail furling system generally consists of a cylindrical tube rotating around a fixed rope. The sail is attached to the furler by a rope passing through a groove in the furler.

[0076] The 20 sail is thus a biplane, with sails 22 and 23 allowing it to capture a greater part of the wind force.

[0077] In the first embodiment of the sail, illustrated in Figures 2 and 3, the mast 31 carries several spars 35 inclined relative to the mast 31. In this embodiment, the spars 35 extend in planes perpendicular to the mast 31, at different heights on the mast 31. Each end of each spar 35 carries a yard, 34 and / or 36. The yards, 34 and / or 36, may be parallel to each other. Each yard, 34 and / or 36, extends along an axis, respectively, 26 and / or 28, parallel to a plane perpendicular, not shown, to the axis 25 of the mast 31. Each sail is, for example, flexible and mounted between two yards, 34 and / or 36, parallel. Preferably, the yards, 34 and / or 36, on one side of the mast 31 are parallel to each other. The yards 36 on one side of the mast 31 are preferentially parallel to the yards 34 on the other side of the mast 31. In other words, the axes 26 of the yards 34 are preferentially parallel to the axes 28 of the yards 36.

[0078] In variants (not shown), the axes 26 of the yards 34 on one side of the mast 31 are intersecting with the axes 28 of the yards 36 on the other side of the mast 31. In other words, the yards 34 on one side of the mast 31 are parallel to each other. The yards 36 on one side of the mast 31 have, for example, different orientations from those of the yards 34 on the other side of the mast 31. In other words, the orientations of the yards 91 on one side of the mast 93 may be independent of the orientations of the yards 92 on the other side of the mast, the connections between the yards and the spars being pivoting and motorized for this purpose. An acute salient angle, called an “incident” angle, not shown, formed by the intersecting axes 26 and / or 28 may be less than or equal to 20°. An acute salient angle formed, not shown, by the secant axes 26 and / or 28 is preferably less than or equal to 10°.

[0079] In variants, the side members are in two parts mounted on a pivot connection with an axis parallel to that of the mast and a motor varies the angle between these two parts of the side members.

[0080] Between two yards, 34 and / or 36, successive on the same side of the mast 31 is a flexible sail, for example made of canvas. The flexible sails to the left of the mast 31 are referenced 32 and the flexible sails to the right of the mast 31 are referenced 33. A rope 37 connects two ends of yards, 34 and / or 36, successive on the same side of the mast 31, in front of the sail (on the left in figures 2 and 3), that is to say to the wind. This rope 37 holds the front edge of the flexible sail 32 or 33. In figures 2 and 3, there are shown, on each side of the mast 31, three flexible sails 32 and 33 stretched between four yards, 34 and / or 36. Of course, the number of sails and yards can be different in variants of this first embodiment of the sail structure which is the subject of the invention.

[0081] In Figure 2, we observe, in the form of arrows F1 and F2, the resultants of the aerodynamic forces on the sails 32 and 33 for a crosswind. We note that these resultants F1 and F2 are behind the axis of rotation 25 and therefore make the sail 30 capable of erasing. More generally, the position of the aerodynamic force depends on the incidence of the profile with the wind. In the present case this force is located at approximately 25% of the length of the chord. This situation is the most unfavorable for the rigging to have an erasing capacity. It corresponds to a low incidence, of the order of 20°. When the incidence increases, the point of application of the force “moves back” to end up at 50% of the chord for an incidence of 90°. In other words, if the rotation of the mast 31 is free around the axis of rotation 25, the sail 30 automatically orients itself towards the wind, which has the effect of canceling out the resultants of the aerodynamic forces.In Figure 15, we see the sail 30 with sails, 32 and / or 33, variously deployed. For example, furlers (not shown) are positioned at the windward end of the yards, 34 and / or 36, and allow the flexible sails, 32 and 33, to be deployed or folded. A furler can further deploy or fold one sail, 32 and / or 33, relative to the other.

[0082] The wing 30 is, for example, free to rotate around the mast 31 while retaining its biplane configuration.

[0083] In variants, the sail 30 is free to rotate around the mast 31 while maintaining the same acute salient angle formed by the axes, 26 and / or 28, of the yards, 34 and / or 36.

[0084] The second embodiment of the sail 40 illustrated in Figure 4 is similar to the first embodiment, with two flexible sails on each side of the mast, except that the mast 31 is replaced by two parallel masts 38 and 39 which jointly carry the spars 35 and the yards, 34 and / or 36.

[0085] In Figure 5, we observe a nautical vessel 50 equipped with two masts 31 on its deck 54 and two sails 30 around these masts 31. In this Figure 5, all the sails 32 and 33 are deployed and taut.

[0086] As illustrated in Figure 6, in the different speeds of the nautical vessel 60 comprising the sails 30, the motorized rotation of the mast 31 makes it possible to capture the power of the wind, according to sail orientations known in the prior art.

[0087] In Figure 7, we observe a nautical vessel 70 equipped with a sail 30 around a foremast 31 and a sail 40 around a double mizzen mast 38 and 39. In this Figure 7, the upper sails 32 and 33 are folded and the lower sails 32 and 33 are deployed and stretched.

[0088] In Figure 8, we see the boat 50 with its sails 30 free from the vertical of the boat deck. For this purpose, the foremast 31 is turned so that the maximum extension of the yards, 34 and / or 36, is turned towards the bow of the boat 50. Conversely, the mizzen mast 31 is in a position where the maximum extension of the yards, 34 and / or 36, is turned towards the stern of the boat 50. The implementation of the present invention thus makes it possible to free the central part of the deck 54 of the boat 50 from any overhanging sail element, which facilitates the loading or unloading of materials or other products.

[0089] In the first two embodiments of the sail, 30 and 40, these sails are fabric-covered and self-erasing biplanes. The yards are straight and the aerodynamic forces are behind the axis of rotation 25 of the mast 31 or 38 and 39.

[0090] These first two embodiments 30 and 40 of the wing which is the subject of the invention have the following advantages:

[0091] - a large sail area,

[0092] - limited air draft,

[0093] - good resistance in strong winds,

[0094] - small footprint on deck, - automation of the mast rotation motor,

[0095] - self-erasing.

[0096] In the third embodiment of the sail, illustrated in Figures 9 to 13, a mast 81 carries several spars 85 inclined relative to the mast 81. In this embodiment, the spars 85 extend in planes perpendicular to the mast 81, at different heights on the mast 81. Each end of each spar 85 carries a rotation shaft 89 (see Figure 10) of a rigid half-sail 83 relative to a downstream rigid half-sail 82. A hinge 86 and a deployment and folding means 87 connect the downstream half-sail 82 to an upstream half-sail 83. It is noted that the rotation shafts 89 (see Figure 10) carried by the ends of spars 85 on the same side of the mast can be independent and rotated independently by several motors (not shown), or combined and, in this case, be rotated for the same engine (not shown). In Figure 9, an upstream half-sail 83 is folded over a downstream half-sail 82 and three upstream half-sails 83 are deployed.

[0097] As illustrated in Figure 10, the deployment and folding means 87 connecting the downstream half-sail 82 to an upstream half-sail 83 may be a jack, for example electric or hydraulic. Increasing the extension of this jack allows the deployment of the upstream half-sail 83. On the contrary, reducing the extension of the jack allows the folding of the upstream half-sail 83 onto the downstream half-sail 82.

[0098] In figures 9 and 13, there are shown, on each side of the mast 81, two sails articulated between three spars 85. Of course, the number of sails and spars can be different in variants of this third embodiment of the sail structure which is the subject of the invention.

[0099] In embodiments, such as those shown in Figures 9 to 13, each half-sail, 82 and / or 83, is an arc of a parabola. In other words, the half-sails, 82 and 83, follow, for example, a symmetrical profile with respect to an axis of rotation of the rotation shaft 89.

[0100] As illustrated in Figure 11, in the different speeds of a fourth embodiment of the nautical vessel 90 comprising the sails 80, the motorized rotation of the mast 81 around the axis of rotation 25 and the deployment and folding of the upstream rigid half-sails 83 makes it possible to capture the power of the wind, according to sail orientations known in the prior art. However, a means for controlling the means 87 for deploying and folding the upstream rigid half-sails 83 is configured to fold the half-sails 83 when tacking and jibing the vessel 90 and to reverse the curvature of the deployed sail, between starboard and port tack.

[0101] On the same spar 85, the half-sails, 82 and 83, on one side of the spar are, for example, symmetrical to the half-sails, 82 and 83, on another side of the spar relative to an axis 95, the axis 95 being the axis of symmetry of the mast 93, perpendicular to the axis 25. In other words, the half-sails, 82 and 83, on one side of a spar 85 have, for example, the same orientation as the half-sails, 82 and 83, on another side of this spar 85.

[0102] Figure 13 shows a third particular embodiment of the wing illustrated in Figure 9. For the same spar 85, the half-sails, 82 and 83, on one side of the spar are, for example, asymmetrical to the half-sails, 82 and 83, on another side of the spar, relative to the axis 95. In other words, the half-sails, 82 and 83, on one side of a spar 85 have, for example, a different orientation from the half-sails, 82 and 83, on another side of this spar 85.

[0103] Figure 12 shows a fifth embodiment of a nautical vessel 100 equipped with a sail 80 around a foremast 81 and a sail 80 around a mizzenmast 81. In this figure 12, the upstream half-sails 83 are folded. Note that, in strong winds, the upstream half-sails 83 can be folded, while maintaining a wind catch to move the vessel forward. On the contrary, in light winds, the upstream half-sails 83 are deployed to maximize the windward lift.

[0104] In Figure 14, we observe different looks of a sixth particular embodiment of a nautical vessel 105 comprising the sails 80. The orientations of the spars 85 of the upstream mast 81 may be different from the orientations of the spars of the downstream mast 81. The orientations of the half-sails, 82 and / or 83, of the upstream mast 81 may be the same as the orientations of the half-sails, 82 and / or 83, of the downstream mast 81, even if the respective spars 85 of the upstream mast 81 and the downstream mast 81 have a different orientation.

[0105] The third embodiment of the wing 80 which is the subject of the invention has the following advantages:

[0106] - it is self-erasing in all wind conditions,

[0107] - it has a large surface area,

[0108] - it has a limited air draft,

[0109] - it presents effective profiles at small Rn,

[0110] - it has strong resistance in strong winds,

[0111] - it has a small footprint on deck,

[0112] - it is easy to automate, with a motorization of the rotation of the mast around the axis of rotation 25 and a motorization of the rotation of the upstream half-sails around the axis of the hinges 86, and

[0113] - it is durable.

[0114] Of course, as in the second embodiment of the sail which is the subject of the invention, the mast 81 can be replaced by two parallel masts jointly carrying the spars 85.

Claims

CLAIMS 1. Biplane wing (30, 40, 80) of a nautical vessel (50, 60, 70, 90, 100, 105) comprising a deck (54, 94), characterized in that it comprises: - a mast (31, 38, 39, 81), extending along an axis (25), mounted inclined relative to the deck of the boat, on a motorized shaft with an axis of rotation inclined relative to the deck of the boat, - a plurality of side members (35, 85) mounted inclined relative to the mast, on either side of the mast, - for each side of the mast, between the ends of two successive spars located on the same side of the mast, a sail (32, 33, 82, 83) and motorized means (87) for deploying and folding this sail.

2. Sail (30, 40) according to claim 1, which comprises a yard (34, 36) at each end of each spar, each yard extending along an axis (26, 28) perpendicular to the axis of the mast (25), each sail (32, 33) being flexible and mounted between two parallel yards, the yards on one side of the mast being parallel to each other.

3. Sail (30, 40) according to claim 2, in which the axis (26, 28) of a yard (34, 36) on one side of the mast (31, 38, 39), is parallel to the axis (26, 28) of a yard (34, 36) on the other side of the mast.

4. Sail (30, 40) according to claim 2, in which the axis (26, 28) of a yard (34, 36) on one side of the mast (31, 38, 39), is intersecting with the axis (26, 28) of a yard (34, 36) on the other side of the mast.

5. Sail (30, 40) according to one of claims 2 to 4, which comprises, for each flexible sail (32, 33), a retaining rope (37) between the yards (34, 36) surrounding the sail, this rope being positioned to windward of the yards and the motorized means for deploying and folding this sail comprises a sail furler consisting of a cylindrical tube rotating around a fixed cable, the sail being associated with the furler by a rope passing through a groove in the furler.

6. Wing (30, 40) according to one of claims 2 to 5, which comprises two parallel masts (38, 39) jointly carrying the spars (35).

7. Sail (80) according to one of claims 1 to 6, in which at least one sail comprises a rigid upstream half-sail (83) and a rigid downstream half-sail (82) connected to each other by a hinge (86) mounted between two ends of successive spars (85).

8. A sail (80) according to claim 7, wherein the half-sails (82, 83) on one side of a spar (85) have the same orientation as the half-sails (82, 83) on the other side of this spar (85).

9. A sail (80) according to claim 7, wherein the half-sails (82, 83) on one side of a spar (85) have a different orientation than the half-sails (82, 83) on the other side of this spar (85).

10. A sail (80) according to one of claims 7 to 9, in which each half-sail (82, 83) is a parabola arc.

11. Sail (80) according to one of claims 7 to 10, in which the motorized means (87) for deploying and folding this sail comprises a jack.

12. Sail (80) according to one of claims 7 to 11, which comprises a means for controlling the motorized means for deploying and folding an upstream half-sail (83) relative to the downstream half-sail (82), this control means being configured to fold the half-sails onto each other when tacking and jibing and to reverse the curvature between starboard and port tack.

13. Nautical vessel (50, 60, 70, 90, 100, 105) comprising at least one sail (30, 40, 80) according to one of claims 1 to 12.

14. Boat (50, 70, 100) according to claim 13, which comprises a sail (30, 40, 80) according to one of claims 1 to 12 around a foremast (31, 81) and a sail (30, 40, 80) according to one of claims 1 to 12 around a mizzen mast (31, 38, 39, 81).

Images