A wind propulsion element comprising a watertight bulkhead equipped with a movable sealing device between an open and a closed position

The sail propulsion element with a movable sealing device and controlled air management system addresses the challenges of sail positioning, providing efficient and controlled inflation/deflation of inflatable chambers for improved wind propulsion.

FR3161408B1Active Publication Date: 2026-03-20MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
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Patent Information

Authority / Receiving Office
FR · FR
Patent Type
Patents
Current Assignee / Owner
Filing Date
2024-04-22
Publication Date
2026-03-20

AI Technical Summary

Technical Problem

Existing wind propulsion systems, such as those described in WO 2022/248812, face challenges in improving the control and efficiency of lowering and raising inflatable sails, particularly in ensuring correct positioning during these operations.

Method used

A sail propulsion element with a watertight partition equipped with a movable sealing device that allows controlled sequential inflation and deflation of inflatable chambers, facilitated by air injection and extraction devices, and a control unit that manages these processes based on pressure sensor feedback.

Benefits of technology

Enables precise control over the raising and lowering of inflatable sails, preventing flapping and ensuring optimal positioning, thereby enhancing the operational efficiency and reliability of wind-powered vehicles.

✦ Generated by Eureka AI based on patent content.

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Abstract

This sail propulsion element (6) comprises: a mast (8); an inflatable sail (10); a head (12); a sail receptacle (14); a watertight bulkhead (18) separating a lower inflatable chamber (28) and an upper inflatable chamber (24); a conduit (30); an air injection device (34) in fluidic communication with the conduit (30); and an air extraction device (36) in fluidic communication with the lower inflatable chamber (28). The watertight bulkhead (18) is provided with a sealing device (32) movable between open and closed positions. The watertight bulkhead (18) is movable between close and distant positions. Figure for the abbreviation: Fig 2
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Description

Title of the invention: Sail propulsion element comprising a watertight bulkhead provided with a movable sealing device between an open and a closed position. Technical field

[0001] The invention relates to a wind-powered vehicle and is in the field of wind propulsion or hybrid wind propulsion.

[0002] In particular, the invention relates to a sail propulsion element. Previous techniques

[0003] Prior art is known a wind propulsion element intended to equip a wind-powered vehicle and described in document WO 2022 / 248812.

[0004] The sail propulsion element described in this document comprises a mast, an inflatable sail having a plurality of cells spaced by ribs made of a flexible material allowing air to pass through, at least one air duct disposed between the inside and outside of the inflatable sail, at least one means of injecting air into the inflatable sail, a headboard and a sail receptacle.

[0005] The lowering (doing so that the sail is lowered) and raising (doing so that the sail is raised) of the sail propulsion element described in document WO 2022 / 248812 have proven to be improvable. In fact, checking the correct positioning of the inflatable sail during these two operations has proven necessary.

[0006] The invention aims at better control of the lowering and raising of an inflatable sail. Description of the invention

[0007] The invention relates to a sail propulsion element comprising:

[0008] a mast;

[0009] an inflatable sail internally delimiting an inflatable cavity, the sail comprising an upper part, a lower part, a leading edge and a trailing edge, the sail comprising different curves forming bulges,

[0010] a headboard arranged on the upper part of the sail;

[0011] a sail receptacle disposed on the lower part of the sail;

[0012] at least one watertight partition separating an inflatable compartment in the inflatable cavity lower and an upper inflatable chamber;

[0013] at least one conduit in fluidic communication between the exterior of said sail propulsion element and the inflatable cavity;

[0014] at least one air injection device in fluidic communication with the duct; and

[0015] at least one air extraction device in fluidic communication with the lower inflatable chamber.

[0016] Said watertight partition is provided with a movable sealing device between an open position for inflation of the upper inflatable chamber, and a closed position for maintaining the upper inflatable chamber in the inflated state.

[0017] Said watertight partition is movable relative to the sail receptacle between at least one close position in which the conduit extends through the sealing device which is in its open position, and at least one distant position in which the sealing device which is in its closed position is at a distance from the conduit, said watertight partition being movable under the effect of a displacement of the head relative to the sail receptacle.

[0018] Said movable watertight partition between a close position and a distant position, and the sealing device of said movable watertight partition between an open position and a closed position, allow a controlled sequential inflation and a controlled sequential deflation of the inflatable sail.

[0019] In particular, it is possible to inflate the upper chamber while keeping the lower chamber deflated and pressed against the wing receptacle. Similarly, it is possible to deflate the lower chamber while keeping the upper chamber inflated.

[0020] By controlling the raising and lowering of the inflatable sail, it is also prevented from flapping.

[0021] Said air injection device may include a fan.

[0022] Said air extraction device may include a fan.

[0023] The leading edge is the front part of an airfoil. The leading edge contains the stagnation point where the flow of an incident fluid splits into two.

[0024] The trailing edge is the rear part of the aerodynamic profile considered in the direction of the fluid flow.

[0025] The headpiece follows at least part of the upper contour of the sail.

[0026] The sail receptacle is suitable for receiving the lowered sail. It can incorporate other functions such as taking up tension forces supplied by the sail, housing actuators, sensors, or a control unit for the inflatable sail.

[0027] The mast can be telescopic or non-extendable.

[0028] When the mast is telescopic, it consists of different elements capable of sliding successively relative to each other to deploy or retract.

[0029] When the mast is telescopic, the head is fixed to the upper element of the telescopic mast and is able to maintain a degree of freedom in rotation around a longitudinal axis of the mast, the upper element of the mast being able to rotate around the longitudinal axis or the head being able to rotate around the mast.

[0030] When the mast is inextensible, the head is movable along the mast.

[0031] The telescopic or non-extendable mast may be free to rotate relative to said hull. Alternatively, the mast may be fixed, at least in rotation, relative to said hull.

[0032] The inflatable sail is attached to the headrest so as to go down or up at the same time as the headrest.

[0033] The head has sufficient rigidity to transmit various physical forces from the inflatable sail to the mast and to support the weight of the inflatable sail.

[0034] The sail propulsion element may include the sail rotation control unit configured to control the angle of the sail relative to the wind.

[0035] The control unit may also be capable of controlling the raising and lowering of the inflatable sail.

[0036] The inflatable sail may comprise two canvases connected to each other around their perimeter and forming the inflatable cavity.

[0037] Each piece of fabric for the inflatable sail can have a weight between 50 and 300 g.m2.

[0038] The sail propulsion element may further include at least one additional watertight bulkhead defining in the inflatable cavity at least one intermediate inflatable chamber arranged between the upper and lower inflatable chambers.

[0039] Optionally, at least one watertight bulkhead may include a rigid rack. This rigid rack allows the watertight bulkhead to be secured in the sail receptacle.

[0040] Said watertight bulkhead equipped with said rigid racket allows reefing by folding the inflatable sail from the bottom up to said watertight bulkhead.

[0041] Reefing consists of reducing the area of ​​a sail by partially folding it from the bottom, in order to adapt the sail area to the wind strength. Advantageously, at least one groove is formed along the outer surface of the conduit, remaining at a distance from an upper end of the conduit, the groove opening at least into the lower inflatable chamber.

[0042] Said groove allows air to circulate between adjacent boxes delimited by a sealed partition which is located between the upper and lower ends of said groove.

[0043] Preferably, said groove extends to the sail receptacle.

[0044] Advantageously, the sail propulsion element further includes a rope connecting the head to at least said watertight bulkhead so that the rope is taut when the sail is hoisted and inflated.

[0045] Thus, the rope facilitates the hoisting of the inflatable sail by tightening when the compartment located above said watertight bulkhead is inflated.

[0046] The terms "above" and "below" are taken with reference to the vertical direction corresponding to the longitudinal direction of the mast.

[0047] The rope may comprise a plurality of rope segments successively connecting each watertight bulkhead so that each rope segment is taut when the sail is hoisted and inflated.

[0048] According to a first conception, the conduit is mounted on the sail receptacle.

[0049] According to a second alternative design, the conduit is arranged around the mast.

[0050] By arranging the conduit around the mast, it is facilitated to move said partition from the distant position to the close position.

[0051] Advantageously, the sail propulsion element further comprises at least one pressure sensor mounted on said conduit.

[0052] Said pressure sensor facilitates the control of the sail hoisting by measuring the pressure in the chamber into which the conduit opens.

[0053] The control unit may be capable of controlling the operation of said air injection device, said air extraction device and the movement of the headrest according to signals from said pressure sensor.

[0054] The control unit may also be capable of controlling the raising and lowering of the inflatable sail according to signals from said pressure sensor.

[0055] Preferably, the sealing device of said watertight partition automatically moves from its open position to its closed position when the sealing device is at a distance from said conduit, and moves from its closed position to its open position by contact with the conduit.

[0056] Advantageously, the sealing device of said watertight bulkhead is capable of allowing or preventing the circulation of air between the inflatable chambers adjacent to said bulkhead depending on its open or closed position.

[0057] According to a particular design, the sealing device of said watertight partition is provided with sealing lips and in particular with a non-return valve.

[0058] Advantageously, the sail propulsion element includes at least one wire cage arranged in the lower inflatable chamber such that said air extraction device draws air through the wire cage.

[0059] Said wire mesh cage keeps the airtight partitions of said air extraction device at a distance so as not to impede air extraction.

[0060] According to a particular design, said air extraction device is mounted on the sail receptacle.

[0061] The present invention also relates to a wind-powered or hybrid-powered vehicle comprising at least one hull, at least one element of sail propulsion as defined above, the mast of said sail propulsion element being fixed to said hull, the inflatable sail of said sail propulsion element being free to rotate.

[0062] The present invention also relates to a method for hoisting an inflatable sail from a sail propulsion element as defined above, comprising at least:

[0063] simultaneously injecting air into the upper inflatable chamber and sucking air out of the lower inflatable chamber;

[0064] the hoisting of a part of the inflatable sail once the upper inflatable chamber has reached a nominal air pressure so that said watertight bulkhead is located above the duct;

[0065] the injection of air into the lower inflatable chamber; and

[0066] the complete hoisting of the inflatable sail once the lower inflatable chamber has reaches the nominal air pressure.

[0067] The present invention also relates to a method for lowering an inflatable sail of a wind propulsion element as defined above, comprising at least:

[0068] the air intake of the lower inflatable chamber;

[0069] the lowering of part of the inflatable sail so that the conduit extends through the sealing device of said watertight bulkhead;

[0070] the air intake of the upper inflatable chamber; and

[0071] the complete deflation of the inflatable sail. Brief description of the drawings

[0072] The present invention will be better understood upon study of the detailed description of embodiments, taken by way of non-limiting examples and illustrated by the accompanying drawings in which:

[0073] [Fig-1] is a front view of a wind-propelled vehicle according to a first example of the implementation of the invention;

[0074] [Fig.2] and [Fig.3] are profile views of a sail propulsion element during the hoisting its inflatable sail according to the first example of embodiment of the invention;

[0075] [Fig.4] is a detail view of [Fig.2];

[0076] [Fig.5A], [Fig.5B] and [Fig.5C] are perspective views during a process of hoisting an inflatable sail of a sail propulsion element according to the invention;

[0077] [Fig.6] is a schematic representation of a lowering method according to the invention;

[0078] [Fig.7] is a view analogous to that of [Fig.3] of a sail propulsion element according to a second embodiment of the invention; and

[0079] [Fig.8] is a view analogous to that of [Fig.3] of a sail propulsion element according to a third example of an embodiment of the invention. Detailed description

[0080] Fig. 1 illustrates a wind-powered vehicle 2, for example a sailboat or ship, comprising a hull 4 and a wind propulsion element 6. Alternatively, the wind-powered vehicle 2 could comprise several hulls 4, for example when the wind-powered vehicle 2 is a catamaran or trimaran.

[0081] The sail propulsion element 6 comprises a self-supporting mast 8 made solid to the hull 4 by a support 9 ([Fig.2]), an inflatable sail 10, a head 12 and a sail receptacle 14.

[0082] The inflatable sail 10 internally delimits an inflatable cavity. The inflatable sail 10 here comprises two sails 16 connected to each other around their perimeter so that the mast 8 extends longitudinally between the two sails 16. The inflatable sail 10 comprises an upper part, a lower part, a leading edge and a trailing edge.

[0083] The head 12 is arranged on the upper part of the inflatable sail 10, the sail receptacle 14 being arranged on the lower part of the inflatable sail 10. The head 12 is supported by the mast 8. The head 12 is here fixed to the upper end of the mast 8.

[0084] The sail receptacle 14 is fixed on the support 9. As will be described in more detail later, the head 12 is movable relative to the sail receptacle 14 which is fixed.

[0085] The sail receptacle 14 extends from the leading edge to the trailing edge. The sail receptacle 14 is intended to receive all or part of the inflatable sail 10 when it is deflated.

[0086] The inflatable sail 10 is made free to rotate relative to the hull 4 of the wind-powered vehicle 2 by any suitable means. In particular, the wind propulsion element 6 includes a control unit 17 for the inflatable sail 10 capable of changing the orientation of the inflatable sail 10 relative to the hull 4 of the wind-powered vehicle 2 in order to optimize or regulate the aerodynamic thrust generated by the inflatable sail 10.

[0087] Each of the two canvases 16 is, for example, made of a coated material, in particular textile, which allows it to meet conditions of mechanical resistance, sealing, and protection against fire and UV radiation.

[0088] The two interconnected canvases 16 form a closed inflatable cavity. The inflatable sail 10 comprises a plurality of partitions 18 made of a flexible material and extending each within the inflatable cavity from the leading edge to the trailing edge. The partitions 18 delimit within the inflatable cavity a plurality of cells 20 in the direction of the span of the inflatable sail 10. The partitions 18 are fixed to the sail, for example by sewing, welding or gluing, and give the inflatable sail 10 different curves forming bulges.

[0089] The inflatable sail 10 here has a profile that remains permanently symmetrical when inflated, regardless of the movement of the wind-powered vehicle 2, the orientation of the inflatable sail 10, and the direction and intensity of the wind. Alternatively, an asymmetrical profile of the inflatable sail 10 could be provided when inflated.

[0090] At least part of the partitions 18, and here each partition 18, is made of a waterproof material 18. The waterproof material of the waterproof partitions 18 is, for example, a coated material, in particular textile, which meets the requirements of mechanical resistance, waterproofing, and fire protection.

[0091] The watertight partitions 18 separate the inflatable cavity into different compartments 24, 26, 28, and here into an upper compartment 24, a plurality of intermediate compartments 26 and a lower compartment 28.

[0092] Each box 24, 26, 28 is here made up of a cell 20. Alternatively, part of the partitions 18 could be made of a permeable material so that some boxes are made up of a plurality of cells 20. Alternatively, a single partition 18 could form a watertight partition 18.

[0093] Optionally, at least one or each watertight bulkhead 18 may include a rigid rack, in order to press the watertight bulkhead 18 concerned into the sail receptacle 14 and to allow reefing.

[0094] With reference to Figures 2 to 4, the sail propulsion element 6 comprises a conduit 30 extending through the sail receptacle 14 from the outside of the sail propulsion element 6 to the inside of the inflatable cavity. The conduit 30 opens on one side to the outside of the sail propulsion element 6 and on the other side into a compartment 24, 26, 28 of the inflatable cavity, such that the compartment 24, 26, 28 into which the conduit 30 opens is in fluidic communication with the outside of the sail propulsion element 6.

[0095] The conduit 30 is a rigid element, for example an element made of material with the receptacle of the sail 14, or an element attached to the receptacle of the sail 14.

[0096] Each watertight bulkhead 18 is equipped with a sealing device 32 which is movable between an open position for inflating the chamber 24, 26 located above the watertight bulkhead 18 in question and a closed position for maintaining the chamber 24, 26 located above the watertight bulkhead 18 in its inflated state. Thus, the chambers 24, 26, 28 are inflated successively.

[0097] Each watertight partition 18 is movable relative to the veil receptacle 14 between a close position in which the conduit 30 extends through the sealing device 32 which is in its open position, and a distant position in which the sealing device 32 which is in its closed position is at a distance from the conduit 30. As will be described in more detail later, each watertight partition 18 is movable relative to the veil receptacle 14 under the effect of the displacement of the head 12.

[0098] The sealing device 32 of each watertight bulkhead 18 allows air to circulate between the inflatable chambers 24, 26, 28 adjacent to the watertight bulkhead 18 considered in its open position and prevents air from circulating between these adjacent inflatable chambers 24, 26, 28 in its closed position.

[0099] Each sealing device 32 is, for example, provided with sealing lips.

[0100] When sealing lips are used, these are extensible at least up to a maximum diameter of the conduit 30. The sealing lips allow the relevant sealing device 32 to automatically move from the closed position to the open position by contact with the conduit 30, and to automatically move from the open position to the closed position when the conduit 30 is at a distance from the sealing device 32, and therefore when the relevant sealing partition 18 is in its distant position.

[0101] Each sealing device 32 may further include a non-return valve (not shown).

[0102] The non-return valve can move to its open position through contact with the conduit 30, and it can move to its closed position automatically as soon as the conduit 30 is no longer in contact with the valve. In its closed position, the non-return valve allows air to flow from the inflatable chamber 26, 28 located below to the inflatable chamber 24, 26 located above the watertight bulkhead 18 carrying the non-return valve, provided the pressure difference between these adjacent inflatable chambers 24, 26, 28 is sufficient. In its closed position, the non-return valve prevents air from flowing from the inflatable chamber 24, 26 located above to the inflatable chamber 26, 28 located below the watertight bulkhead 18 carrying the non-return valve.Thus, the non-return valve makes it possible to compensate for possible air leaks from the inflatable chamber 24, 26 located above the watertight bulkhead 18 which carries the non-return valve in question, in particular by maintaining the pressure in the inflatable chamber 24, 26 concerned, for example air leaks through seams of the inflatable sail 10. In particular, and in the absence of an anomaly, each watertight bulkhead 18 is in the position close to the sail receptacle 14 when the inflatable chamber 24, 26 located above this watertight bulkhead of 18 considered is deflated or in. deflated part. Similarly, each watertight bulkhead 18 is in a position away from the sail receptacle 14 when the inflatable chamber 24, 26 located above the watertight bulkhead 18 in question is inflated to a nominal pressure, the nominal pressure corresponding to the pressure expected in the inflatable cavity when the inflatable sail 10 is fully hoisted and inflated.

[0103] The sail propulsion element 6 includes an air injection device 34, in particular reversible, for example a reversible fan, in fluidic communication with the conduit 30. The air injection device 34 is arranged in the conduit 30 and is capable of injecting air into the inflatable cavity, in particular into the inflatable chamber 24, 26, 28 into which the conduit 30 opens.

[0104] The conduit 30 has a variable diameter, in particular an increasing diameter from an upper end of the conduit 30 towards the sail receptacle 14, so as to guide each watertight bulkhead 18 during the movement of the sail receptacle 14 during the hoisting and lowering operations.

[0105] The sail propulsion element 6 includes at least one reversible air extraction device 36, for example a reversible fan, in fluidic communication with the lower inflatable chamber 28. The sail propulsion element 6 here includes two air extraction devices, each mounted on the sail receptacle 14. Each air extraction device 36 is capable of drawing air from the lower inflatable chamber 28 so as to extract the air from the lower inflatable chamber 28 to the outside of the sail propulsion element 6.

[0106] At least one groove 38, and here two grooves 38, are formed along the outer surface of the conduit 30. Each groove 38 extends across the surface of the conduit 30 from the sail receptacle 14 to the upper end of the conduit 30, remaining at a distance from this upper end. Thus, each groove 38 opens into the lower inflatable chamber 28 and into each fully deflated inflatable chamber 24, 26. Alternatively, the conduit 30 could be devoid of groove 38.

[0107] The sail propulsion element 6 includes a pressure sensor 40 mounted on the conduit 30 and capable of measuring the pressure of the inflatable chamber 24, 26, 28 into which the conduit 30 opens. Alternatively, the sail propulsion element 6 could include a pressure sensor mounted in each inflatable chamber 24, 26, 28.

[0108] The control unit 17 is capable of controlling the operation of the air injection device 34 and each air extraction device 36 according to signals from the pressure sensor 40. The control unit 17 is also capable of controlling the raising and lowering of the inflatable sail 10 according to signals from the pressure sensor 40.

[0109] Figures 5A, 5B and 5C illustrate a method of hoisting the inflatable sail 10 of the sail propulsion element 6, in particular hoisting in such a way as to successively inflate the inflatable chambers 24, 26, 28.

[0110] Initially, the inflatable sail 10 is fully lowered and fully deflated so that all the watertight partitions 18 are arranged in the sail receptacle 14.

[0111] We begin by simultaneously injecting air into the upper inflatable chamber 24 and by simultaneously drawing air from the lower inflatable chamber 28. This step corresponds to [Fig. 2] in which the air injection device 34 injects air into the upper inflatable chamber 24 through the conduit 30 which then opens into the upper inflatable chamber 24. Simultaneously, the air extraction device 36 extracts air from the lower inflatable chamber 28, the air extraction device 36 also extracting air from the intermediate inflatable chambers 26 through the grooves 38 of the conduit 30. During this step, each airtight bulkhead 18 is in the close position while the upper inflatable chamber 24 is inflating.

[0112] Next, when the upper inflatable chamber 24 has reached the predetermined nominal air pressure detected by the pressure sensor 40, a portion of the inflatable sail 10 is hoisted so that the watertight bulkhead 18 adjacent to the upper inflatable chamber 24 is positioned above the conduit 30. The hoisting of the inflatable sail 10 is controlled by the control unit 17 and is achieved by deploying the mast 8, which, in the illustrated embodiment, is telescopic. During the hoisting of the inflatable sail 10, the head 12 is movable relative to the fixed sail receptacle 14.

[0113] We then proceed to the inflation of the next intermediate inflatable chamber 26, corresponding to [Fig.3], and then to the hoisting of the sail in the same manner.

[0114] The intermediate inflatable chambers 26 are thus successively inflated and the inflatable sail 10 is progressively hoisted until the lower chamber 28 is inflated.

[0115] Air extraction from the lower inflatable chamber 28 is then stopped, and air is injected into the lower inflatable chamber 28 by means of the air injection device 34, which performs the injection of air into the lower inflatable chamber 28. For example, each air extraction device 36 is reversible so as to be able to inject air into the lower inflatable chamber 28. Alternatively, each extraction device 36 can be equipped with a valve to prevent air from flowing through the air extraction device 36 during the injection of air into the lower inflatable chamber 28.

[0116] Finally, we complete the hoisting of the inflatable sail 10 so that the inflatable sail 10 is fully hoisted.

[0117] Fig. 6 schematically illustrates a method for lowering the inflatable sail 10 of the sail propulsion element 6. Lowering the inflatable sail 10 of the sail propulsion element 6 is carried out in the reverse order of its raising, in particular so as to successively deflate the inflatable chambers 24, 26, 28.

[0118] Initially, the inflatable sail 10 is fully hoisted and inflated to the nominal pressure, as illustrated in [Fig.1].

[0119] In a step 41A, air is first drawn from the lower inflatable chamber 28, each air extraction device 36 performing in particular the drawing of air from the lower inflatable chamber 28. For example, the air injection device 34 is reversible so as to be able to draw air from the inflatable chamber 24, 26, 28 into which the conduit 30 opens. Alternatively, the air injection device 34 can be equipped with a valve to prevent the circulation of air through the air injection device 34 when the inflatable chamber 24, 26, 28 into which the conduit 30 opens is deflated.

[0120] During step 41A, part of the inflatable sail 10 is lowered so that the conduit 30 then extends through the sealing device 32 of the watertight bulkhead 18 adjacent to the lower inflatable chamber 28. The lowering of the inflatable sail 10 is controlled by the control unit 17 and is achieved by retracting the mast 8. During the lowering of the inflatable sail 10, the head 12 is movable relative to the fixed sail receptacle 14.

[0121] The lowering is continued, during a step 41B, by successively deflating each intermediate inflatable chamber 26 in a similar manner.

[0122] Finally, during a step 41C, the air is sucked out of the upper inflatable chamber 24 and the lowering continues until the inflatable sail 10 is completely lowered, all the watertight bulkheads 18 then being arranged in the sail receptacle 14.

[0123] The embodiment illustrated in [Fig.7] differs from the first embodiment illustrated in Figures 2 to 4 in that the sail propulsion element 6 includes a rope 42 connecting the head 12 to the watertight bulkhead 18 adjacent to the upper inflatable chamber 24. The rope 42 then successively connects each watertight bulkhead 18 until it connects the watertight bulkhead 18 adjacent to the lower inflatable chamber 28.

[0124] The length of the rope 42 is such that the rope 42 is taut when the inflatable sail 10 is fully hoisted and inflated to the nominal pressure.

[0125] More specifically, the rope 42 comprises a rope segment 44 connecting the head 12 to the watertight bulkhead 18 adjacent to the upper inflatable chamber 24, and a plurality of rope segments 44 each connecting two successive watertight bulkheads 18. The length of each rope segment 44 is such that this segment is taut when the inflatable chamber 24, 26, 28 in which this segment of rope 44 extends is at nominal pressure.

[0126] The embodiment illustrated in [Fig. 7] also differs from the first embodiment in that the sail propulsion element 6 comprises a wire mesh cage 46 arranged in the lower inflatable chamber 28 so that each air extraction device 36 draws air through the wire mesh cage 46. The wire mesh cage 46 is supported by the sail receptacle 14. The wire mesh cage 46 extends from each air extraction device 36 to the duct 30, so that air is able to flow from each air extraction device 36 to the duct 30, and in particular from each groove 38 of the duct 30 to each air extraction device 36.

[0127] The embodiment illustrated in [Fig.8] differs from the first embodiment illustrated in Figures 2 to 4 in that the conduit 30 is arranged around the mast 8. The conduit 30 has a variable diameter, in particular increasing diameter from the upper end of the conduit 30 towards the sail receptacle 14, so as to guide each watertight bulkhead 18 during the movement of the sail receptacle 14 during hoisting and lowering operations.

[0128] In particular, each sealing device 32 equipped with sealing lips is guided along the mast 8 and along the conduit 30.

[0129] Each sealing device 32 equipped with sealing lips is in the closed position when it forms a seal by contact with the mast 8.

[0130] In the embodiments described above, the mast 8 is telescopic and made up of different elements that slide successively along one another to extend or retract. The head 12 is fixed to the last element of the mast 8. Alternatively, the mast 8 could be fixed, with the head 12 then moving along the mast 8. In another alternative, it might also be possible to combine a telescopic mast 8 with a head 12 that slides along this telescopic mast 8.

Claims

Demands

1. Sail propulsion element (6) comprising: - a mast (8); - an inflatable sail (10) internally delimiting an inflatable cavity, the sail (10) comprising an upper part, a lower part, a leading edge and a trailing edge, the sail (10) comprising various curves forming bulges, - a head (12) disposed on the upper part of the sail (10); - a sail receptacle (14) disposed on the lower part of the sail (10); characterized in that it comprises: - at least one watertight bulkhead (18) separating in the inflatable cavity a lower inflatable chamber (28) and an upper inflatable chamber (24); - at least one conduit (30) in fluidic communication between the exterior of said sail propulsion element (6) and the inflatable cavity; - at least one air injection device (34) in fluidic communication with the conduit (30);and - at least one air extraction device (36) in fluidic communication with the lower inflatable chamber (28), - said watertight bulkhead (18) being provided with a sealing device (32) movable between an open position for inflation of the upper inflatable chamber (24), and a closed position for maintaining the upper inflatable chamber (24) in the inflated state, - said watertight bulkhead (18) being movable relative to the sail receptacle (14) between at least a close position in which the conduit (30) extends through the sealing device (32) which is in its open position, and at least a distant position in which the sealing device (32) which is in its closed position is at a distance from the conduit (30), said watertight bulkhead (18) being movable under the effect of a displacement of the head (12) relative to the sail receptacle (14).;

2. Sail propulsion element (6) according to claim 1, further comprising at least one additional watertight bulkhead (18) defining in the inflatable cavity at least one intermediate inflatable chamber (26) arranged between the upper and lower inflatable chambers (24, 28).

3. Sail propulsion element (6) according to claim 1 or 2, wherein at least one groove (38) is formed along the external surface of the conduit (30) while remaining at a distance from an upper end of the conduit (30), the groove (38) opening at least into the lower inflatable chamber (28).

4. Sail propulsion element (6) according to any one of claims 1 to 3, further comprising a rope (42) connecting the head (12) to at least said watertight bulkhead (18) so that the rope (42) is taut when the sail (10) is hoisted and inflated.

5. Sail propulsion element (6) according to any one of claims 1 to 4, wherein the conduit (30) is arranged around the mast (8).

6. Sail propulsion element (6) according to any one of claims 1 to 5, further comprising at least one pressure sensor (40) mounted on said conduit (30).

7. Sail propulsion element (6) according to claim 6, further comprising a control unit (17) capable of controlling the operation of said air injection device (34), said air extraction device (36) and the movement of the head (12) according to signals from said pressure sensor (40).

8. Sail propulsion element (6) according to any one of claims 1 to 7, wherein the sealing device (32) of said watertight bulkhead (18) automatically moves from its open position to its closed position when the sealing device (32) is away from said conduit (30), and moves from its closed position to its open position by contact with the conduit (30).

9. Sail propulsion element (6) according to any one of claims 1 to 8, wherein the sealing device (32) of said watertight bulkhead (18) is capable of permitting or preventing the circulation of air between the inflatable chambers (24, 26, 28) adjacent to said watertight bulkhead (18) depending on its open or closed position.

10. Sail propulsion element (6) according to any one of claims 1 to 9, wherein the sealing device (32) of said watertight bulkhead (18) is provided with sealing lips and in particular with a non-return valve.

11. Sail propulsion element (6) according to any one of claims 1 to 10, comprising at least one wire cage (46) arranged in the lower inflatable chamber (28) such that said air extraction device (36) draws air through the wire cage (46).

12. Sail propulsion element (6) according to any one of claims 1 to 11, wherein said air extraction device (36) is mounted on the sail receptacle (14).

13. A wind-powered or hybrid-powered vehicle (2) comprising at least one hull (4), at least one wind propulsion element (6) according to any one of claims 1 to 12, the mast (8) of said wind propulsion element being integral with said hull (4), the inflatable sail (10) of said wind propulsion element (6) being free to rotate.

14. A method for hoisting an inflatable sail (10) from a sail propulsion element (6) according to any one of claims 1 to 12, comprising at least: - simultaneously injecting air into the upper inflatable chamber (24) and drawing air from the lower inflatable chamber (28); - hoisting a portion of the inflatable sail (10) once the upper inflatable chamber (24) has reached a nominal air pressure such that said watertight bulkhead (18) is located above the conduit (30); - injecting air into the lower inflatable chamber (28); and - fully hoisting the inflatable sail (10) once the lower inflatable chamber (28) has reached the nominal air pressure.

15. Method for lowering an inflatable sail (10) of a sail propulsion element (6) according to any one of claims 1 to 12, comprising at least: - the suction of air from the lower inflatable chamber (28); - the lowering of a part of the inflatable sail (10) so that the conduit (30) extends through the sealing device (32) of said watertight bulkhead (18); - the suction of air from the upper inflatable chamber (24); and - the complete lowering of the inflatable sail (10).