Hydrofoil comprising a retractable foil assembly

Abstract

The invention relates to a hydrofoil with a hull and an internal structure, which comprises: - a foil assembly comprising a mast rigidly connected to a foil; - a hole drilled through the hull and housing the mast; and - a joining part rigidly connected to the mast, the joining part forming a sliding connection with a frame rigidly connected to the internal structure of the hydrofoil so that the foil assembly is movable between at least one raised position and one lowered position and so that the considerable mechanical forces to which the foil assembly is exposed during the sailing of the hydrofoil are transmitted to the internal structure via the frame. The invention also relates to a ship appendage, in particular a foil assembly suitable for being installed on a hydrofoil according to the invention.

Description

DESCRIPTION TITLE: HYDROFOIL COMPRISING A RETRACTABLE FOIL ASSEMBLY TECHNICAL FIELD OF THE INVENTION

[0001] The present invention falls within the field of naval design. It relates more particularly to a hydrofoil comprising at least one set of retractable foils. STATE OF THE ART

[0002] The prior art knows hydrofoils with foils. A hydrofoil is a boat capable of planing, that is, of rising out of the water and maintaining its balance out of the water under the effect of speed, by means of several lifting surfaces placed under its hull.

[0003] Such a lifting plane is most commonly referred to as a "foil", borrowed from English. For ease of reading, in this application, the term "foil" is used. The foil may also be called a "wing", "lifting wing", "lifting plane" or be referred to by the English term "hydrofoil". The foil is supported by a generally straight structural element that extends under the hull called a "mast". The term "foil assembly" refers to the assembly formed by a mast and a foil.

[0004] Foiling hydrofoils have a very deep draft. This draft does not allow navigation in shallow waters and can hinder the docking of the hydrofoil, its transport out of the water and maintenance operations. To overcome this problem, the prior art discloses hydrofoils equipped with retractable foil assemblies.

[0005] The retractable foil assemblies, for example those described in the application published under number FR 3 093 073 A1 or in the application published under number CN 105 905 232 A, are retractable by vertical translation of the mast or by rotation of the foil assembly. Other systems are configured to fold the foil back on itself or along the mast.

[0006] Foil assemblies retractable by vertical translation require the provision of a well, i.e. a clearance in the hull. The function of the well is to shelter the mast and ensure the transfer of forces undergone by the foil assembly to the hull. To achieve this, the well has force relays, commonly called upper wedges and lower wedges, on its walls and generally has a shape matching that of the mast. These complementary shapes also have the advantage of ensuring the well is watertight.

[0007] The transmission of mechanical forces between the foil assembly and the hull via the walls of the well and / or the complementary shapes of the mast and the well mean that any change made to the mast during the design of the hydrofoil requires redesigning the foil well to adapt it to the change made. These complementary shapes also prevent the replacement of the foil assembly initially planned on a hydrofoil with a foil assembly of different dimensions.

[0008] In the case of retractable foils, the well and the wedges have a dual role of guiding and transmitting forces from the foil to the hull. The robustness of this dual function is limited because the desired effects are opposite. OBJECTS OF THE INVENTION

[0009] The present invention aims to remedy all or part of these drawbacks.

[0010] To this end, according to a first object, the present invention aims at a hydrofoil provided with a hull and an internal structure, which comprises: - a foil assembly comprising a mast attached to a foil, - a well drilled across the hull and sheltering the mast, and - a connecting piece secured to the mast, said connecting piece forming a sliding connection with a frame secured to the internal structure of the hydrofoil so that the foil assembly is movable between at least one raised position and one lowered position and so that the significant mechanical forces undergone by the foil assembly during navigation of the hydrofoil are transmitted to the internal structure, via the chassis.

[0011] For the purposes of this application, the term "hull" or "hull bottom" refers to the outer shell of the vessel, consisting of the part of the planking intended to be submerged. Foil assemblies or any other appendage (rudder, propeller, anti-drift planes, keel) are considered to be separate from the hull according to this definition.

[0012] For the purposes of this application, the term "internal structure" refers to the structural framework of the vessel, including the girder, longitudinal and transverse bulkhead but not including the hull as defined above.

[0013] The mast is a substantially straight structural element that extends outside the hull and whose functions are to support the foil and to contribute to the hydrodynamic characteristics of the foil assembly. For the purposes of this application, "transverse" means an orientation substantially orthogonal to the main axis of the mast and "longitudinal" means an orientation substantially parallel to the main axis of the mast.

[0014] The terms "raised position" and "lowered position" refer to the position of the foil assembly. In the raised position, the foil assembly is retracted or "up" so that less of the mast emerges from the hull. In the raised position, the draft is shallower. In the lowered position, the foil assembly is deployed or "down" so that more of the mast emerges from the hull. In the lowered position, the draft is greater. As many positions as necessary can be provided along the travel of the slide connection with the chassis.

[0015] According to the provisions of the invention, the forces experienced by the foil assembly during navigation of the hydrofoil are transmitted to the internal structure, via the chassis. In other words, all of the significant mechanical forces are transmitted to the internal structure of the hydrofoil and not to its hull via the well.

[0016] For the purposes of this application, "significant" force means a non-negligible force. For example, the forces supported by the walls of the well are negligible if they are 10 times lower than those supported by the frame.

[0017] For example, the forces supported by the walls of the well are negligible if they do not exceed 1000 Newtons, preferably if they do not exceed 800 Newtons, preferably if they do not exceed 600 Newtons.

[0018] These arrangements are advantageous because they allow the well and hull to be structurally decoupled from the foil assembly. This fundamental difference compared to prior art hydrofoils allows the design of a hull and a hull well without taking into account the characteristics of the foil assembly, and vice versa. This allows for faster and freer design of the hydrofoil because a modification made to the foil assembly does not necessarily imply structural modifications to the hull.

[0019] In addition, the invention is advantageous because it allows easier replacement of the foil assembly during the life of the hydrofoil. A replacement may be desirable to improve the performance of the hydrofoil or to replace a defective foil assembly. It is easily understood that, since the dimensions of the foil well and the hull are no longer intrinsically linked to those of the foil assembly, the provision of a replacement foil assembly is facilitated and the design or choice of a new foil assembly is freer.

[0020] Another advantage of the hydrofoil that is the subject of the invention is that the mechanical stresses experienced by the hull, at the level of the well(s), are less than for the hydrofoils of the prior art. In addition, the strength requirements of the well are reduced to the strict minimum to withstand the parasitic forces not absorbed by the chassis. This generates a significant weight saving in the well area.

[0021] In embodiments, the joining piece is a removable piece attached to the mast.

[0022] Thanks to these provisions, in the event of replacement of the foil assembly, the joining piece can be removed from the mast and used again on a separate foil assembly.

[0023] In embodiments, the mast includes a head configured to cooperate with the joining piece.

[0024] The term "masthead" means a part of the mast at the end of the mast opposite the end intended to be immersed in water. The masthead preferably has means facilitating a connection with the joining piece. These means comprise, for example, one or more rectangular sections allowing the head to be clamped or pre-positioned screw-nut type attachment means, or any other suitable attachment means.

[0025] The masthead is located above the bottom of the keel, regardless of the position of the foil assembly. Therefore, it is not necessary for the head to have hydrodynamic characteristics useful for navigation.

[0026] Thanks to these provisions, the attachment between the removable junction piece and the mast of the foil assembly is facilitated.

[0027] In embodiments, the hydrofoil is configured so that the mast does not contact the walls of the foil well when the hydrofoil is being navigated. In other words, a non-zero minimum gap is provided between the surface of the mast and the wall of the well.

[0028] According to the invention, the foil well does not act as a mechanical force relay. Thus, a space can be provided between the surface of the mast and the wall of the well. These arrangements make it possible to replace the foil assembly in place on the hydrofoil with another foil assembly of larger cross-section. Such clearance ensures that the relative deformations of the mast and the well do not generate any or little force on the walls of the well. For example, the maximum force on the walls of the well does not exceed 1000 Newtons.

[0029] In embodiments, the minimum distance separating the surface of the mast from the wall of the well is at least 1 centimeter, preferably at least 2 centimeters, very preferably at least 5 centimeters.

[0030] The minimum distance between the mast surface and the well wall is defined as the shortest distance between a point on the mast surface of the foil assembly and a point on the well wall.

[0031] In embodiments, the sliding connection between the frame and the foil assembly is ensured by the cooperation between at least one carriage and at least one rail.

[0032] In embodiments, the axis of the frame is offset from the axis of the mast and the connecting piece transversely connects the mast and the frame.

[0033] In other words, the mast and the frame are arranged side by side and not in a row. Thanks to these arrangements, the vertical space requirement of the group formed by the frame and the foil assembly is reduced.

[0034] In embodiments, movement of the foil assembly along the rail is motorized using a linear electromechanical actuator. For example, the linear electromechanical actuator comprises a ball screw and a motor.

[0035] The decorrelation of the shapes of the mast and the well and a fortiori the provision of a space between the wall of the well and the surface of the mast are likely to cause sealing problems between the interior and exterior of the hull, via the well.

[0036] Thus, in embodiments, the hydrofoil comprises a means for sealing the well. For example, the means for sealing the well comprises a flexible membrane pierced with a slot into which the mast of the foil assembly is slid.

[0037] In other embodiments, or in addition, the junction piece crushes a seal resting on the top of the well when the system is in the low position, ensuring an extension of the height of the well by a length at least equal to that of the junction piece.

[0038] Thanks to these provisions, the sealing of the well is improved.

[0039] As detailed above, the provisions of the invention, reinforced in certain particular embodiments, facilitate the replacement of one set of foils by another.

[0040] Thus, in embodiments, the hydrofoil comprises a first set of foils and a second set of foils interchangeable with each other. For example, a hydrofoil may be provided with two separate sets of foils, including one set of foils allows for a more "sporty" ride, i.e. faster, compared to the other set of foils, which allows for a ride with better stability. In another example, a hydrofoil is supplied with two sets of foils with masts of different lengths, so that by interchanging the sets of foils, the draft of the hydrofoil can be changed.

[0041] According to a second aspect, the invention relates to a ship appendage which comprises a mast intended to be positioned in a well drilled across the hull of a hydrofoil and a connecting piece secured to the mast, the connecting piece being configured to form a sliding connection with a frame secured to the internal structure of the hydrofoil, such that the ship appendage can be made movable between at least one raised position and one lowered position and such that the significant mechanical forces undergone by the ship appendage during navigation of the hydrofoil are transmitted to the internal structure of the hydrofoil, via the frame.

[0042] A ship appendage is any appendage that emerges from the hull of the ship and is submerged in the water. For example, a ship appendage is chosen from a set of foils, a rudder, a propeller support, or an anti-drift plan. The ship appendage is supported by a generally straight structural element that extends below the hull called a mast.

[0043] In particular, the invention according to its second aspect relates to a foil assembly intended to be positioned in a well drilled across the hull of a hydrofoil and comprising a mast secured to a foil and a joining piece, the joining piece being configured to form a sliding connection with a frame secured to the internal structure of the hydrofoil, so that the foil assembly can be made movable between at least one raised position and one lowered position, and so that the significant mechanical forces undergone by the foil assembly during navigation of the hydrofoil are transmitted to the internal structure of the hydrofoil, via the frame.

[0044] The characteristics and advantages of the ship appendage and the foil assembly which are the subject of the invention being similar to those of the hydrofoil which are the subject of the invention, they are not repeated again here. BRIEF DESCRIPTION OF THE FIGURES

[0045] 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 hydrofoil which is the subject of the present invention, with reference to the appended drawings, in which: [Fig 1] schematically represents a side view of a first particular embodiment of a hydrofoil which is the subject of the invention, [Fig 2] schematically represents a front view of the first embodiment of a hydrofoil which is the subject of the invention, [Fig 3] represents, schematically and in perspective view, the detail of a chassis and a connecting piece according to a particular embodiment of the hydrofoil which is the subject of the invention, [Fig 4] represents, schematically and in longitudinal section, the detail of the chassis and the junction piece of figure 3 and [Fig 5] represents different cross-sections of the masthead, the mast and the well, according to a particular embodiment of the hydrofoil which is the subject of the invention, said sections being superimposed on each other to assess their relative dimensions.

[0046] The reference numbers mentioned in the figures refer to: To a 100 hydrofoil, To 110, 120 and 130 foil sets, At foils 111 and 121, At well 115 and its wall 116, At masts 112, 122 and 132, At contour 113 of mast 112 To propellers 123 and 133, At foil wells 115, 135, Has a masthead 118 and its outline 119, On chassis 140, At rails 141 and 142, To a linear actuator 144, To blocking means 145 and 146, To a junction piece 160, which comprises a part 161 ensuring the attachment with the mast of a foil assembly and a part 162 ensuring a sliding connection with the frame 140 To carts 164, 165 and 166 and To a 190 hull. DETAILED DESCRIPTION OF THE INVENTION

[0047] The present 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 each to scale but that the scales between them may vary.

[0048] Figures 1 and 2 show, respectively, a side view and a front view of a hydrofoil 100. The hydrofoil 100 has a hull 190 and includes a first foil assembly 110, a second foil assembly 120, and a third foil assembly 130.

[0049] The foil assemblies, 110, 120 and 130, are here shown in lowered positions. The first foil assembly 110 is positioned at the bow, it comprises a foil 111 secured to a mast 112. A first well 115 is arranged in the hull 190, it makes it possible to shelter a more or less significant part of the mast 112 depending on whether the first foil assembly 110 is raised or lowered.

[0050] The second and third sets of foils, 120 and 130, are positioned at the stern. They are each equipped with a mast, respectively 122 and 132, and a propulsion propeller, respectively 123 and 133, but are both integral with the same foil 121. A second well (not visible) and a third well 135, respectively house the masts 122 and 132.

[0051] The foil assemblies, 110, 120 and 130 are moved by vertical translation between a raised position and a lowered position. As many additional positions as necessary can be provided on the travel path of the foil assemblies, without deviating from the invention.

[0052] According to the embodiment of the hydrofoil illustrated in Figures 1 and 2, the second and third sets of foils, 120 and 130, move in concert to keep the foil 121 vertical. In other embodiments, each set of foils may comprise a separate foil and their movements may be decorrelated.

[0053] We will now describe, with reference to Figures 3 and 4, an embodiment of a chassis 140 and a connecting piece 160 according to a particular embodiment of the hydrofoil which is the subject of the invention. A chassis and a connecting piece of the type shown in Figures 3 and 4 are for example installed overhanging each of the three wells described above for the hydrofoil 100.

[0054] The connecting piece 160 has a part 161 ensuring the attachment to the mast of a foil assembly and a part 162 ensuring a sliding connection with the frame 140. The upper part of the mast fixed by the part 161 ensuring the attachment to the mast is called the “mast head”.

[0055] Preferably, the mast head 118 is configured to facilitate attachment between the mast and the connecting piece. For example, the mast head has a simple polygonal cross-section, or a round cross-section, complementary to the shape of the part 161 of the connecting piece 160.

[0056] According to the embodiment illustrated in figures 3 and 4, the part 161 comprises two jaws gripping a mast head 118 of rectangular section in a vice. Any element allowing a solid connection between the junction piece and the mast can be envisaged without deviating from the invention. Advantageously, the mast head may have standardized dimensions, that is to say dimensions common to several heads of several different foil assemblies.

[0057] Preferably, the connecting piece 160 is a removable piece fixed to the mast. In other embodiments, the mast and the connecting piece are formed as a single piece.

[0058] The portion 162 of the connecting piece 160 providing a sliding connection with the chassis 140 is for example formed of extensions which extend transversely relative to the axis of the mast. Each extension comprises at its end a carriage, 164, 165, and 166, configured to cooperate with a rail, 141 or 142. The rails 141 and 142 are two vertical rails parallel to each other.

[0059] According to this configuration, the axis of the chassis 140, that is to say a vertical axis centered between the two rails 141 and 142, is offset relative to the axis of the mast and the junction piece 160 connects transversely, here horizontally, the mast and the chassis 140.

[0060] The rails 141 and 124 are supported by a frame 140 which in turn is fixed to the internal structure of the hydrofoil. The forces experienced by the foil assembly during navigation are intense. Thanks to the invention, these forces are transmitted to the frame and then dissipated to the internal structure. The homogenization of the forces on the stiff structure formed by the frame before the forces are transmitted to the internal structure helps to dissipate the forces. Particular care will be taken at the attachment points between the frame 140 and the internal structure so that the mechanical stresses experienced are dissipated effectively. For example, the attachment between the frame and the internal structure of the hydrofoil is ensured by 18 screw-nut fasteners distributed over the frame.

[0061] The transition of the foil assembly from a raised position to a lowered position is motorized. Preferably, this motorization is provided by means of a linear electromechanical actuator 144. For example, the linear electromechanical actuator comprises a ball screw and a motor.

[0062] The foil assembly is locked in the raised or lowered position by a locking means. Any locking means allowing the sliding connection between the foil assembly and the chassis to be locked may be used without deviating from the invention. In particular, the locking means may comprise at least one electric or pneumatic cylinder.

[0063] For example, the locking means comprises a first electric cylinder comprising a first piston 145 which, when deployed, engages in a catch and immobilizes in place two carriages, including the carriage 166, of the junction piece 160, so that the foil assembly is immobilized in the raised position. And, the chassis 140 comprises a second cylinder comprising a second piston 146 which, when deployed, immobilizes in place two carriages, including the carriage 166, of the junction piece 160, so that the foil assembly is immobilized in the lowered position.

[0064] In embodiments (not shown), the motorization of the movement of the foil assembly is provided by means of a piston.

[0065] Figure 5 shows a diagram illustrating the relative dimensions of the masthead, the mast and the shaft of the first embodiment of the hydrofoil which is the subject of the invention. This figure shows in bold lines the outline 119 of the masthead 118, the outline 113 of the mast 112 and the wall 116 of the shaft 115.

[0066] It is observed that the mast head 118 has a substantially rectangular contour 119 allowing easy attachment to the junction piece.

[0067] Preferably, each of the foil assemblies and the sheltering wells are configured to prevent the mast sheltered by each well from coming into contact with the walls of the well when the hydrofoil is sailing.

[0068] The dimensions of the contour 113 of the mast 112 and the wall 116 of the well 115 are determined to leave a non-zero minimum space between the surface of the mast, illustrated by the contour 133, and the wall 116 of the well.

[0069] For example, the minimum distance separating the surface of the mast from the wall of the well is at least 1 centimeter, preferably 2 centimeters, preferably at least 5 centimeters, very preferably at least 10 centimeters.

[0070] It is understood that if the foil assembly is interchangeable, the minimum distance between the well wall and the mast surface may vary. This distance, however, may not be less than the minimum distance.

[0071] In embodiments (not shown), the hydrofoil 100 comprises, in at least one of its wells intended to house a mast, a means ensuring the sealing of the well. For example, the means ensuring the sealing of the well comprises a flexible membrane pierced with a slot into which the mast of the foil assembly is slid. According to another example compatible with the first, the means ensuring the sealing comprises an extensible seal connecting the well to the junction piece, so that the junction piece crushes a seal the seal rests on the top of the well when the system is in the low position, ensuring an extension of the height of the well by a length at least equal to that of the junction piece.

Claims

CLAIMS A hydrofoil (100) having a hull (190) and an internal structure, characterized in that it comprises: - a foil assembly (110, 120, 130) comprising a mast (112, 122, 132) secured to a foil (111, 121), - a well (115, 135) drilled across the hull and housing the mast, and - a connecting piece (160) secured to the mast, said connecting piece forming a sliding connection with a frame (140) secured to the internal structure of the hydrofoil, so that the foil assembly is movable between at least one raised position and one lowered position and so that the significant mechanical forces undergone by the foil assembly during navigation of the hydrofoil are transmitted to the internal structure, via the frame. Hydrofoil (100) according to claim 1, wherein the connecting piece is a removable part fixed to the mast. Hydrofoil (100) according to claim 2, wherein the mast comprises a head (118) configured to cooperate with the connecting piece. Hydrofoil (100) according to any one of claims 1 to 3, configured so that the mast does not come into contact with the walls of the well during navigation of the hydrofoil.Hydrofoil (100) according to the preceding claim, in which the minimum distance separating the surface of the mast from the wall of the well is at least 1 centimeter, preferably at least 2 centimeters, very preferably at least 5 centimeters. Hydrofoil (100) according to any one of claims 1 to 5, in which the sliding connection between the chassis and the foil assembly is ensured by the. cooperation between at least one carriage (164, 165, 166) and at least one rail (141, 142). Hydrofoil (100) according to any one of claims 1 to 6, wherein the axis of the chassis is offset relative to the axis of the mast and wherein the connecting piece transversely connects the mast and the chassis. Hydrofoil (100) according to any one of claims 1 to 7, wherein the movement of the foil assembly along the rail is motorized by means of a linear electromechanical actuator (144). Hydrofoil (100) according to claim 8, wherein the linear electromechanical actuator comprises a ball screw and a motor. . Hydrofoil (100) according to any one of claims 1 to 9, which comprises means ensuring the sealing of the well. . Hydrofoil (100) according to claim 10, in which the means ensuring the sealing of the foil well comprises a flexible membrane pierced with a slot into which the mast of the foil assembly is slid.Hydrofoil (100) according to any one of claims 10 to 11, in which the means ensuring the sealing of the foil well comprises a seal resting on the top of the well crushed by the joining piece when the system is in the low position ensuring an extension of the height of the well by a length at least equal to that of the joining piece. . Hydrofoil (100) according to any one of claims 1 to 12, which comprises a first set of foils and a second set of foils, interchangeable with each other. . A ship appendage characterized in that it comprises a mast intended to be positioned in a well drilled across the hull of a hydrofoil and a. connecting piece secured to the mast, the connecting piece being configured to form a sliding connection with a frame secured to the internal structure of the hydrofoil, so that the ship's appendage can be made movable between at least one raised position and one lowered position and so that the significant mechanical forces undergone by the ship's appendage during navigation of the hydrofoil are transmitted to the internal structure of the hydrofoil, via the frame.

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