Sail for wind-powered craft, and corresponding craft

Abstract

Sail for wind-powered craft, and corresponding craft. The invention relates to a sail (10) for a wind-powered craft (1), said sail being intended to be mounted along a mast (6). The sail (10) has an aerodynamic cross-section comprising, on the one hand, a peripheral contour (12) including a leading edge (14), a trailing edge (16), and two adjacent surfaces (18) each extending between the leading edge and the trailing edge; and on the other hand, an interior space surrounded by the peripheral contour (12) and configured to accommodate the mast (6).The sail (10) comprises at least one longitudinal inflatable envelope (20) having two facing walls, an inner and an outer wall, each wall comprising a layer of textile and connected to each other by a multitude of connecting threads distributed over the entire surface of said layers and of substantially equal lengths, forming a structure, preferably closed or watertight, adapted for inflation, and at least a portion of the peripheral contour (12) is formed by said at least one inflatable envelope (20). The invention also relates to a wind-powered or hybrid craft comprising such a sail (10). Figure for the abstract: Fig. 1.

Description

Title of the invention: Sail for wind-powered craft, and corresponding craft. Technical field

[0001] The present invention relates to the field of sails for wind-powered craft, in particular inflatable sails having an aerodynamic profile. Prior art

[0002] In the field of sailing navigation, the propulsion of the ship is classically ensured by one or more simple sails made of stretched canvas.

[0003] However, it is known to use thick-profile sails, whose performance is superior to that of simple sails. Among thick-profile sails, a distinction is made between rigid wings and flexible wings.

[0004] Rigid wings are extremely complex mechanical assemblies whose manufacturing cost limits their use to high-level competition. Furthermore, this type of wing does not allow for the reduction in sail area required for cruise ships.

[0005] Flexible wings are wings made of a double layer of fabric, hoisted on a spar and tensioned by rigid elements (battens or cambers as in document FR2556310) to maintain a thick profile. This type of wing has the major drawback of profile deformation between the rigid elements. Furthermore, the disadvantages of tensioning forces associated with conventional sails persist: the fabric must be stretched tightly from top to bottom to best maintain the chosen aerodynamic profile.

[0006] French patent FR 3 008 382 B1 discloses a vertically oriented wing-shaped canopy composed of a leading edge and a trailing edge, each consisting of a piece of double-walled fabric in which the warp threads are bonded to the facing weft threads. By varying the length of these bonding threads during weaving, the spacing between the two walls creates a defined canopy profile. These double-walled fabric pieces are closed by a fabric glued and sewn at the top and bottom of the generated profile, the whole assembly being made airtight by coating with an elastomeric resin. The maintenance of the resulting profile is ensured by inflating the canopy, this air pressure being independent of the static or dynamic pressure of the air circulating around the profile.

[0007] However, such a wing presents several disadvantages. Firstly, the manufacture of such double textile pieces, with warp yarns cooperating with the weft yarns of the two facing walls, is complex, particularly when these connecting yarns have varying lengths depending on the shape of the aerodynamic profile. required (the two walls having non-parallel faces). Such a three-dimensional weave necessitates significant and costly adaptations to current weaving machines. Furthermore, excessive tension on one of the threads can lead to the tearing of a weft thread, creating a hole or tear in one of the walls, affecting the airtightness of the sail and consequently its rigidity and therefore its aerodynamic performance.

[0008] Document FR 3 073 817 relates to a wing-shaped canopy with an aerodynamic profile comprising, between its leading edge and trailing edge, at least one closed flexible envelope having, between its leading edge end and its trailing edge end, a first lateral wall and a second lateral wall. These lateral walls are spaced apart, creating an internal space between them that can be inflated to form a rigid profile. The internal space of the envelope is equipped with rows of wires extending from its leading edge end to its trailing edge end. The wires are held alternately on the inner face of the first lateral wall and the inner face of the second lateral wall of the envelope by means of bonding or welding. These bonded or welded wires ensure the maximum separation between the two lateral walls when the envelope is inflated.Each row of wires is arranged in a crenellated pattern, in the shape of battlements whose apexes correspond to the bonding or welding areas on the inner faces of the side walls of the casing.

[0009] Such a wing-shaped sail thus presents, in its inflated state, a rigid, undeformable profile. The said bonding threads are independent of the warp and weft threads of the textile material that may form the sail's outer walls.

[0010] However, manufacturing such sails, with connecting wires cooperating with each of the two facing walls, is also complex, particularly because the length of the connecting wires varies according to the shape of the required aerodynamic profile. Such three-dimensional manufacturing therefore also requires expensive machinery. Description of the invention

[0011] The present invention aims to solve the various technical problems stated above. In particular, the present invention aims to provide a sail, notably an inflatable one, for a wind-powered craft, in the form of a wing with an aerodynamic profile, that is simpler to manufacture while remaining robust. The present invention also aims to provide an inflatable sail for a wind-powered craft, the aerodynamic profile of which can be easily modified on demand.

[0012] Thus, according to one aspect, a sail for a wind-propelled craft is proposed, said sail being intended to be mounted substantially vertically along a mast said device, wherein the sail extends in a longitudinal direction and has an aerodynamic cross-section comprising a peripheral outline and an interior space enclosed by the peripheral outline and configured to accommodate the mast. The peripheral outline comprises: a leading edge, a trailing edge, and two adjacent surfaces, or side walls, each extending between the leading edge and the trailing edge. The sail comprises at least one longitudinal inflatable envelope having two facing walls, inner and outer, said two walls each comprising a layer of textile and being connected to each other by a multitude of connecting threads distributed over the entire surface of said layers and of substantially equal lengths, forming a structure, preferably closed or watertight, adapted to be inflated. At least a portion of the peripheral outline is formed by said at least one inflatable envelope.

[0013] The structure of the inflatable sail according to the present invention thus comprises at least one volume formed from a dropstitch-type material, which is initially substantially flat. This volume makes it possible, in particular, to obtain at least part of the surface, or skin, of the inflatable sail with the desired aerodynamic profile. Such dropstitch materials are commonly used to manufacture, for example, stand-up paddleboards. They are, in particular, simpler to use and shape than prior art materials having a distance between opposing walls that varies along the sail profile, because, in the present invention, the dropstitch material forms all or part of the surface of the aerodynamic profile, and not all or part of the aerodynamic volume, as in the prior art.Thus, only the outer walls of the inflatable envelope according to the present invention contribute to the aerodynamic shape of the sail: the inner walls are oriented towards the interior space of the sail.

[0014] Thus, unlike prior art sails where the inflatable volume was delimited by the two opposing surfaces of the wing-shaped sail and formed the aerodynamic profile of the sail, the inflatable volume of the sail according to the present invention is located only on all or part of the peripheral contour. In other words, the inflatable volume of the sail according to the present invention forms only all or part of the surface of the sail, the internal volume delimited by the sail being primarily an uninflated interior space. Such an inflatable skin-like structure makes it possible, in particular, to use inflatable materials whose opposing walls are spaced substantially the same distance apart. In the sail according to the present invention, the inflatable envelope forming all or part of the peripheral contour of the sail is a substantially flat envelope that maintains substantially the same thickness along the profile of the sail.

[0015] Preferably, said at least one inflatable envelope is patterned so as to form, in particular so that the outer wall of said inflatable envelope forms, at least a part of each adjacent surface, and preferably the leading edge, of the peripheral contour.

[0016] The inflatable envelope can advantageously extend from the leading edge of the sail and along at least a portion of each adjacent surface, towards the trailing edge. Obtaining the desired aerodynamic shape for the leading edge and portions of each adjacent surface can, in particular, be achieved by shaping the initial flat material intended to form the inflatable envelope. Shaping the flat material to obtain an aerodynamic contour proves simpler than creating a three-dimensional volume with an aerodynamic profile. In particular, specific cuts on at least one of the opposing walls of the initial flat material can suffice to obtain an aerodynamic contour, while maintaining the same distance between the two opposing walls, whereas three-dimensional profiled materials require constant adjustment of the distance (and therefore the length of the connecting threads) between the two opposing walls.

[0017] Thus, at least one of said opposing walls of the inflatable envelope has at least one cutout, preferably made along the longitudinal direction, and a sealing means connecting, preferably edge to edge, the sides of the cutout together. Said at least one cutout is positioned and dimensioned in the inflatable envelope so as to obtain the cross-section of the sail with the desired aerodynamic profile.

[0018] Consequently, and despite the use of an inflatable envelope formed from a dropstitch material, i.e., substantially flat, to form the peripheral contour of the sail, the latter nevertheless has an aerodynamically curved profile thanks to a specific pattern. Thus, at least one of the walls of the dropstitch material has one or more cutouts which, after re-sealing, allow a modification of the planar geometry of the dropstitch material, and in particular to obtain a curvature of the peripheral contour enabling the sail to achieve the desired three-dimensional cross-section.

[0019] Indeed, dropstitch material is classically a flat material with two parallel flat main walls connected by threads and a peripheral wall. Unlike prior art sails, it is not the variation in the length of the connecting threads linking the opposite walls, but the specific pattern of one or more inflatable dropstitch envelopes, that makes it possible to obtain the desired curved aerodynamic cross-section of the sail according to the present invention.

[0020] Preferably, the sail comprises a single inflatable envelope, said single inflatable envelope being patterned to form the leading edge and at least a part of each adjacent surface of the peripheral contour.

[0021] In order to simplify the inflation and deflation of the sail, but also its assembly, the sail may include a peripheral contour, or skin, formed at least in part by a single inflatable volume.

[0022] Preferably, the inflatable envelope is patterned by modifications to the surface of one of the walls in relation to the other, in particular by local modifications such as cutouts, removal of portions or overlaps.

[0023] According to one embodiment, the shaping of the dropstitch material may include, in addition to one or more cuts, a removal of a portion of at least one wall of the dropstitch material, and preferably a removal of a portion of the inner wall.

[0024] Alternatively, the shaping of the dropstitch material may include, in addition to one or more cuts, an overlapping of the edges of the cut of at least one wall of the dropstitch material, and preferably an overlapping of the edges of a cut of the inner wall forming the peripheral contour of the sail.

[0025] It is thus possible to obtain an inner wall with a smaller surface area than that of the outer wall, so that they remain substantially parallel to each other all along the peripheral perimeter.

[0026] Preferably, the sail also includes a longitudinal flap, preferably inflatable and more preferably separate from said at least one inflatable envelope, positioned adjacent to said at least one inflatable envelope so as to form a part of the peripheral contour comprising the trailing edge.

[0027] In such an embodiment, the inflatable sail comprises, in addition to the aerodynamic profile, a steerable flap at the trailing edge. This flap may, in particular, be inflatable and mounted adjacent to the inflatable envelope so as to form, with the inflatable envelope, the peripheral outline of the sail. Thus, despite its inflatable and hollowed-out appearance, the sail according to the present invention can retain advanced functionalities such as the aerodynamic profile and the steerable trailing edge, making it versatile and usable in multiple applications.

[0028] Preferably, the flap is mounted pivoting about a longitudinal axis positioned in a longitudinal plane comprising the leading edge and trailing edge of the sail, for example said flap being connected to said at least one inflatable envelope by a pivot joint, and the sail also includes a control means, preferably inflatable, mounted between said at least one inflatable envelope and the longitudinal flap, and configured to pivot the flap relative to said at least one inflatable envelope.

[0029] The flap can be mounted on the inflatable envelope by a pivot joint and controlled by one or more inflatable elements arranged between the flap and the inflatable envelope. This maintains a sail whose various elements are inflatable, while also providing movable elements, notably the flap, to modify the sail's aerodynamic profile.

[0030] Preferably, the control means comprises two inflatable longitudinal elements mounted on either side of the longitudinal plane comprising the leading edge and trailing edge of the sail.

[0031] The control means may comprise two adjacent inflatable elements, the inflation of one of the two elements allowing one edge of the flap to be moved away from the corresponding edge of the inflatable envelope, and thus allowing the flap to be rotated relative to the inflatable envelope. Such control means thus allow the flap to be rotated, while remaining inflatable and compact.

[0032] Preferably, the sail comprises several means of connection distributed along the longitudinal direction of the sail, and attached to said at least one inflatable envelope.

[0033] In order to keep the sail on the mast, and more particularly the inflatable envelope relative to the mast, the sail may include connecting means positioned regularly along the longitudinal direction of the sail, to mechanically connect it to the mast and transmit to it the forces exerted on the sail.

[0034] Preferably, the sail also includes one or more connecting means, preferably rigid, for example made of composite material, mounted in the interior space and configured to cooperate with the mast and at least a part of the peripheral contour, preferably said at least an inflatable envelope.

[0035] The connecting means can take the geometric form of the cross-section of the interior space of the sail. They can thus be in the form of rigid plates distributed along the longitudinal direction of the sail, and extending into the space left free between the mast and the inflatable envelope.

[0036] According to another aspect, a sail propulsion element is also proposed comprising a sail as described above, a mast and a means of inflating, and possibly deflating, said at least one inflatable envelope.

[0037] According to another aspect, a sail-powered or hybrid craft is also proposed, comprising at least a hull and at least one sail propulsion element as described above. Brief description of the drawings

[0038] [Fig.1] Fig.1 represents, schematically, a wind-powered craft equipped with a sail according to the present invention, seen from above;

[0039] [Fig.2] Fig.2 represents a perspective view of the sail according to the present invention;

[0040] [Fig.3] Fig.3 schematically represents the steps for making the inflatable envelope of the sail according to the present invention;

[0041] [Fig.4] Fig.4 shows, in an enlarged form, the connection between the inflatable envelope and the flap of the sail according to the present invention; and

[0042] [Fig.5] Fig.5 represents a perspective view of the flap according to the present invention. Description of the implementation methods

[0043] Figure 1 schematically illustrates an example of a wind-powered craft 1 according to the present invention, viewed from above. The craft 1, for example a boat such as a monohull, comprises a hull 2 ​​and a wind propulsion element 4 enabling the craft 1 to move using the energy supplied by the wind.

[0044] The sail propulsion element 4 extends substantially along a longitudinal direction D (see [Fig. 2]) which is substantially perpendicular to the upper surface of the hull 2 ​​and substantially parallel to, or even coincident with, the mast 6. The sail 10, which also extends along the longitudinal direction D, can thus have an invariable cross-section along said longitudinal direction D. In this case, the sail 10 can have a generally cylindrical shape. Alternatively, the sail 10 can have a cross-section whose dimensions vary, for example continuously, along the longitudinal direction D, preferably decreasing as one moves away from the hull 2. In this case, the sail 10 can have a generally conical or frustoconical shape.

[0045] The sail propulsion element 4 thus comprises a mast 6, an inflation (and optionally deflation) means 8, and a sail 10 according to the present invention. In particular, since the sail 10 is at least partially inflatable, the inflation means 8 can allow the sail 10 to be raised, at least partially, or lowered, at least partially. Alternatively, the sail 10 can be raised or lowered along the mast 6 by means of halyards, or can be raised or lowered by attachment to a telescopic mast 6 that can be extended or retracted on command.

[0046] The mast 6, on which the sail 10 is mounted, allows, in turn, the forces exerted by the wind on the sail 10 to be transmitted to the hull 2 ​​to move the craft 1 forward.

[0047] The sail 10 is an inflatable sail, but with the aerodynamic profile of a wing. The sail 10 thus has, in cross-section, a peripheral contour 12 which is chosen to have an aerodynamic shape. The peripheral contour 12 comprises a leading edge 12, a trailing edge 14, and two adjacent surfaces 18, or side walls, connecting the leading edge 12 to the trailing edge 14. The peripheral contour 12, and in particular the two adjacent surfaces 18 which are distant from each other and not parallel to each other, therefore delimits the volume of the sail 10.

[0048] As can be seen in the embodiment illustrated in [Fig.1], the sail propulsion element 4, and in particular the sail 10, can present, in particular at rest, a plane of symmetry formed by a longitudinal plane P passing through the leading edge 12, the mast 6 and the trailing edge 16.

[0049] Fig. 2 illustrates more precisely the internal structure of the sail 1. The sail 10 comprises on the one hand an inflatable envelope 20, delimiting in particular an interior space 22, and on the other hand a flap 24. The inflatable envelope 20 and the flap 24 are both longitudinal, cylindrical and / or frustoconical in shape, along the longitudinal direction D.

[0050] In the embodiment illustrated in [Fig.2], the inflatable envelope 20 forms in particular the leading edge 12 of the sail 10, as well as a significant part of the adjacent surfaces 18 of the peripheral contour 12. The flap 24 forms, for its part, the trailing edge 16, as well as a smaller portion of the adjacent surfaces 18 of the peripheral contour 12.

[0051] The interior space 22, surrounded by the inflatable envelope 20, and optionally by the flap 24, is not an inflatable volume of the sail 10. It allows, in particular, the mast 6 to be positioned inside the sail 10, and may include, in particular, connecting means 26 mechanically linking the mast 6 to the peripheral contour 12 of the sail 10, in order to transmit the forces exerted on the sail 10 to the hull 6. The connecting means 26 may, in particular, include plates having the shape of the cross-section of the interior space, and distributed along the mast 6. The connecting means 26 may be rigid, for example made of composite material, and come into contact both with the mast 6 and with at least a portion of the inflatable envelope 20.

[0052] For its part, the flap 24 can be mounted on the inflatable envelope 20 by one or more pivot links 28 (see figures 4 and 5) extending substantially along the direction D.

[0053] Thus, and unlike prior art sails, only the peripheral contour 12 of the sail 10 is formed, at least in part, by an inflatable envelope 20, while the interior space remains free and non-inflatable. The peripheral contour 12 can then be made with an inflatable envelope of substantially constant thickness, that is to say, from a substantially flat inflatable material such as dropstitch material, as will be described below.

[0054] Thus, and as illustrated in [Fig. 3], the inflatable envelope 20 comprises two opposing walls, substantially parallel to each other: an inner wall 20a and a Outer wall 20b. Said walls 20a and 20b each comprise a layer of textile and are connected to each other by numerous connecting threads distributed over the entire surface of said layers, forming a structure suitable for inflation. A peripheral wall, at the ends, is mounted around the perimeter of each of the inner wall 20a and outer wall 20b of the inflatable envelope 20, in order to connect them and form a closed volume.

[0055] To achieve the desired shape for the cross-section of the sail 10, the inflatable envelope 20 was specifically patterned. Figure 3 illustrates the inflatable envelope 20 in its initial flat configuration (right), and the inflatable envelope 20 in its final aerodynamic configuration (left) after the pattern was finalized.

[0056] Thus, to obtain the desired curvature, the inner wall 20a is patterned with longitudinal cutouts, distributed across its width, to remove, for example, portions of the inner wall. Removing such portions, the area of ​​which is chosen according to the zone of the inflatable envelope 20 to obtain the desired curvature, reduces the surface area of ​​the inner wall 20a relative to the outer wall 20b. Once the portions of the inner wall have been cut out, the edges of the cutouts are then joined together, for example edge to edge, with a sealing means, for example, a sealing strip glued or welded to said edges of the inner wall 20a.

[0057] An inflatable envelope 20 is then obtained, the internal volume of which is again closed, and whose walls 20a, 20b are connected to each other by connecting wires of the same length, while presenting an aerodynamic profile.

[0058] Such an inflatable envelope 20 is therefore easier to obtain, and less expensive because the dropstitch plan materials are widespread and classic for those skilled in the art, while retaining the performance of an aerodynamically profiled wing.

[0059] The flap 24 may also be an inflatable element of the sail 10. The flap 24 may have the shape of a triangular-based cylinder or a triangular-based truncated pyramid. One side of the triangle (base) is intended to face the ends of the inflatable envelope 20, while the other two sides are intended to form the trailing edge 16.

[0060] In order to orient the flap 24 relative to the rest of the sail 10, the sail 10 may include inflatable longitudinal elements 30, for example, bladders extending along the longitudinal direction. There may be two inflatable longitudinal elements 30, mounted between the inflatable envelope 20 and the flap 24, for example, on the base of the flap's triangle, each on one side of the pivot joint 28. Thus, by selectively inflating one of the inflatable longitudinal elements 30, it becomes possible to move a portion of the flap 24 away from the inflatable envelope 20, and therefore to rotate it. The inflatable longitudinal elements 30 thus form, with corresponding inflation means (not shown), a control means 32 allowing the flap 24 of the sail 10 to be oriented, while remaining an inflatable and deflatable element like the rest of the peripheral contour 12.

[0061] As illustrated in [Fig.4], the flap 24 may include a base (side opposite the ends of the inflatable envelope 20) formed by a dropstitch material, while the other two sides of the triangular section of the flap 24 are formed by simple walls closing the triangular section and forming the trailing edge 16. In order to shape the triangular flap 24 whose internal volume is not inflated, the flap 24 may also include a cylindrical inflatable element mounted in the flap 24, near the trailing edge 16.

[0062] A pivot joint 28 in the form of a flexible wall connects the flap 24 to the inflatable envelope 20 at the level of the longitudinal plane P. The two inflatable elements 30 of the control means 32 are mounted on either side of said flexible wall to allow rotation of the flap 24 around the pivot joint 28.

[0063] Figure 5 illustrates a perspective view of the longitudinal flap 24 according to another embodiment. Unlike the inflatable envelope 20 or the first embodiment illustrated in Figure 4, the flap 24 of Figure 5 can be a volume delimited by a single, watertight peripheral wall, and thus be fully inflated, rather than by a dropstitch material. In order to obtain a regular triangular cross-section along the entire length of the flap 24, intermediate, non-watertight walls attached to the inner face of the peripheral wall can be provided at regular intervals within the inflatable volume.

[0064] Pivot connecting means 28 may be provided in individual form, for example in the form of hooks configured to cooperate with loops and distributed along the longitudinal direction D, to connect the flap 24 to the inflatable envelope 20. The two inflatable elements 30 of the control means 32 are mounted on either side of said individual connecting means.

[0065] An inflation valve 24a is provided on the flap 24 in order to inflate it.

[0066] Inflation valves 30a are provided for each inflatable element 30 of the control means 32.

[0067] Thus, with the sail according to the present design, it becomes possible to obtain an aerodynamic profile delimited by a peripheral contour formed from a substantially flat inflatable material. It therefore becomes simpler and less expensive to produce an inflatable sail, particularly a large one, while retaining the possibility of having a steerable flap at the trailing edge.

Claims

Demands

1. Longitudinal sail flap (10) for a wind-powered craft (1), said sail extending along a longitudinal direction (D) and intended to be mounted substantially vertically along a mast (6) of said craft, the sail (10) comprising an inflatable envelope and having an aerodynamic cross-section comprising: - a peripheral contour (12) comprising: - a leading edge (14), - a trailing edge (16), and - two adjacent surfaces (18) each extending between the leading edge and the trailing edge, - and an internal space (22) enclosed by the peripheral contour (12) and configured to accommodate the mast (6), in which the flap, preferably inflatable, is positioned adjacent to said inflatable envelope so as to form, with said inflatable envelope, the peripheral contour of the sail, said flap forming the part of the peripheral contour comprising the trailing edge,and preferably a portion of the adjacent surfaces of the peripheral contour, and within which the flap is orientable.

2. Flap according to claim 1, configured to be connected to said inflatable envelope by a pivot joint about a longitudinal axis positioned in a longitudinal plane comprising the leading edge and trailing edge of the sail, for example by one or more pivot joints extending substantially along the longitudinal direction.

3. Flap according to claim 1 or 2, having a cylindrical shape with a triangular base or a truncated pyramid shape with a triangular base.

4. Flap (24) according to the preceding claim, wherein one side of the triangular section of the flap is intended to face the ends of the inflatable envelope (20) and is formed by a dropstitch material, and wherein the other two sides of the triangular section of the flap (24) are formed by simple walls closing the triangular section and forming the trailing edge (16).

5. Flap (24) according to the preceding claim, also comprising a cylindrical inflatable element mounted in the flap, near the trailing edge (16).

6. Flap according to claim 4 or 5 in combination with claim 2, wherein the pivot joint (28) is in the form of a flexible wall connecting the flap (24) to the inflatable envelope (20), at the level of the longitudinal plane comprising the leading edge and trailing edge of the sail.

7. Flap (24) according to claim 3, wherein the flap (24) is a volume delimited by a single sealed peripheral wall, configured to be fully inflated, and wherein the flap preferably includes an inflation valve (24a).

8. Flap (24) according to the preceding claim, also comprising non-watertight interlayer walls attached to an inner face of the peripheral wall, the interlayer walls being provided at regular intervals, inside the inflatable volume.

9. Flap according to claim 7 or 8 in combination with claim 2, wherein the flap comprises pivot connecting means (28) in individual form, for example in the form of hooks configured to cooperate with loops and distributed along the longitudinal direction D, to connect the flap (24) to the inflatable envelope (20).

10. Sail (10) for a wind-powered craft (1) comprising an inflatable envelope and a longitudinal flap according to any one of the preceding claims.

11. Sail propulsion element (4) comprising a sail (10) according to the preceding claim, a mast (6) and a means for inflating (8), and optionally deflating, said at least one inflatable envelope (20).

12. A craft (1) with wind or hybrid propulsion, comprising at least one hull (2) and at least one wind propulsion element (4) according to the preceding claim.

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