sail-propelled ships

Abstract

The invention relates to a vessel at least partially wind-propelled, comprising a double airfoil mounted on a structure that is angle-controlled around an approximately vertical axis depending on the circumstances, the double airfoil comprising a forward flap and an aft flap, at least one of which has a fore-aft asymmetry and separated by a slit, each flap comprising a series of shaped members distributed in height, the structure comprising a forward mast and an aft mast connected by a boom member and by a gaff member. The shaped members of the forward flap can rotate around an axis defined by the forward mast while being traversed by the forward mast, and the shaped members of the aft flap can rotate around an axis defined by the aft mast while being traversed by the aft mast. In addition, the aft mast is twistable and the shaped members of the aft flap are rotationally locked to said aft mast, and the controller can act on the bottom and the top of the aft mast.

Description

Technical Field

[0001] The present invention generally relates to sail propulsion, and more specifically, to a new type of propulsion airfoil for cruise ships and work vessels.

[0002] State of the Art There is a wealth of prior art regarding rigid airfoils for propulsion by natural forces.

[0003] Thus, rigid or semi-rigid airfoils, particularly those having two flaps that provide an adjustable camber to the airfoil, are known from documents US3,332,383A, US4,685,410A, US5,313,905A and US8,635,966B1.

[0004] However, these known airfoils have significant problems with creating a droppable sail and furthermore cannot be reefed. Thus, existing airfoils with two flaps most often have a shrouded mast, and control of the airfoil is effected by both a sheet that forces the camber of the airfoil and a fixed linkage that drives the second flap to reach all or part of the camber at the base of the wing, with a lanyard that generates washout as required. Also, the relative movement of the second flap with respect to the first flap is generally achieved by rotation from an axis located within the profile of the first flap, which is not optimal from a performance perspective and complicates or even makes impossible the implementation of a droppable or reefable airfoil.

[0005] Additionally, document US4,848,258A describes a sail system having three sails and three respective masts, with a structure including two outer masts that can rotate near the central mast. The sail system includes lift members belonging to the sails rather than airfoils. The front and rear gaffs and booms can be forced to rotate about an axis formed by the main mast.

[0006] On the other hand, document EP0,328,254A1 describes a double airfoil sail in which the aft airfoil pivots around an axis located within the volume of the forward airfoil.

[0007] A sail similar to a single airfoil with variable camber is also known from document US4,561,374A. The structure supporting this airfoil rotates on a single mast that passes through the rear portion of the airfoil, where the camber is achieved.

[0008] Also known by WO2018 / 087649 is a vessel that is at least partially wind-propelled, comprising a double airfoil mounted on a structure whose angle is controlled depending on the conditions, wherein the double airfoil comprises a forward flap and a rear flap, at least one of which is asymmetrical and separated by a slit, each flap comprising a series of shaped members distributed in height, the structure comprising a forward mast and a rear mast connected by a boom member and a guff member, the shaped members of the forward flap being traversed by the forward mast and capable of rotating about an axis defined by the forward mast, the shaped members of the rear flap being traversed by the rear mast and capable of rotating about an axis defined by the rear mast, the structure being capable of rotating on a rotation axis formed by the forward mast. [Overview of the project]

[0009] The purpose of this disclosure is to provide improvements to vessels as defined above.

[0010] According to the first improvement, the aft mast is rotatable, the shape member of the aft flap is rotationally locked to the aft mast, and the controller can act on the bottom and top of the aft mast.

[0011] According to the second improvement, each of the forward and aft flaps is provided with a top member that can slide independently of the other along its respective mast, and the vessel further comprises two halyards that can independently raise, lower, and retract the forward and aft flaps.

[0012] According to the third improvement, the forward flap is displaceable over an angular interval defined so as to be angularly offset with respect to a central plane formed by the rotation axes of the two flaps, and the vessel further comprises a controller for controlling the angle of the aft flap with respect to the central plane, the controller being able to cause distinctly different angular displacements in the lower and upper regions of the aft flap, comprising a first actuator acting near the lower region of the aft flap and a second actuator located in the lower region of the airfoil and acting near the upper region of the aft flap via a transmission mechanism passing through one of the masts, and the gaff member belonging to a gaff assembly that makes up at least one of the lowerable and / or retractable forward flap and / or aft flap, comprising the gaff member and a member that can slide along at least one of the masts and is translated and fixed to the upper end of the forward flap and / or the upper end of the aft flap, and the transmission mechanism combined with the second actuator comprises a transmission member attached to the sliding member of the gaff assembly.

[0013] A vessel having any of these improvements may optionally be equipped with the following additional features, individually or in any combination that a person skilled in the art would understand to be technically compatible: * The forward flap is displaceable over a defined angular interval such that it is angularly offset with respect to the median plane formed by the rotation axes of the two flaps. *The forward flap is freely displaced under the influence of wind that biases it laterally. *The vessel will also be equipped with a controller to control the angular displacement of the forward flap. *Angular intervals consist of approximately ±1° to ±15°. *The vessel is further equipped with a controller for controlling the angle of the aft flap relative to the midline. * The controller can cause distinctly different angular displacements in the lower and upper regions of the rear flap. *The controller can also move at least one intermediate region of the rear flap. The controller comprises a first actuator that operates near the lower region of the aft flap, and a second actuator located in the lower region of the airfoil and operating near the upper region of the aft flap via a transmission mechanism that passes through one of the masts. *The vessel further comprises at least one third actuator acting near the intermediate region of the aft flap by a transmission mechanism passing through the mast of the structure. *The actuator is attached to the boom member. * The gaff member comprises the gaff member and a member that can slide along at least one of the masts and is fixed in translation to the upper end of the forward flap and / or the upper end of the aft flap, to create at least one of the lowerable and / or retractable forward flap and / or aft flap. *The transmission mechanism combined with the second actuator comprises a transmission member attached to the sliding member of the gaff assembly. * The vessel has a transmission member within the area of ​​the gaff's fixed member and further comprises at least one halyard attached to the sliding member of the gaff assembly. *The vessel is further equipped with an angle controller that operates in the area of ​​the foot of the forward mast. *This structure does not have a shroud and can rotate 360° in response to the angle controller. *At least one of the flaps is fabricated using an assembly of shaped members having a profiled contour, over which an envelope is stretched. *At least one of the flaps is fabricated using an assembly of nearly rigid or semi-rigid boxes that interlock with each other.

[0014] In addition, the three improvements can be combined with each other.

Brief Description of the Drawings

[0015] Other aspects, objectives, and advantages of the present invention will be given as non-limiting examples and will become more apparent upon reading the following detailed description of its preferred embodiments, which has been made with reference to the accompanying drawings.

[0016] [Figure 1] It is an overall perspective view of a sail-propelled airfoil according to the first embodiment of the present invention. [Figure 2] It is a schematic horizontal sectional view of the airfoil of FIG. 1. [Figure 3A] It is a horizontal sectional view showing the states of the airfoil in four different situations. [Figure 3B] It is a horizontal sectional view showing the states of the airfoil in four different situations. [Figure 3C] It is a horizontal sectional view showing the states of the airfoil in four different situations. [Figure 3D] It is a horizontal sectional view showing the states of the airfoil in four different situations. [Figure 4] It is a bottom perspective view of an assembly of an airfoil structure without an envelope. [Figure 5] It is a top perspective view of the assembly from FIG. 4. [Figure 5A] It is an enlarged top perspective view of the details from FIG. 5. [Figure 6] It is a side elevation view of the upper region from the assembly from FIGS. 4 and 5. [Figure 7] It is a top perspective view of the region shown in FIG. 6. [Figure 8] It is a detailed top perspective view of a member of the airfoil structure. [Figure 9] It is an enlarged-scale bottom perspective view of the lower region from the assembly from FIGS. 4 and 5. [Figure 10]This is an axially tilted perspective view of the region enlarged from Figure 9. [Figure 11] This is a perspective view of the region at an enlarged scale from Figures 6 and 7. [Figure 12] This is a schematic perspective view of an airfoil according to a second embodiment of the present invention. [Figure 13] Figure 12 is a perspective view of the structural members of the airfoil. [Figure 14] This is a schematic side elevation view of the airfoil from Figure 12. [Figure 15] This is a side view of an airfoil according to a third embodiment of the present invention. [Figure 16] Figure 15 shows perspective views of the airfoil from the top and bottom. [Figure 17] Figure 15 shows perspective views of the airfoil from the top and bottom. [Figure 18] Figures 15 to 17 are side cross-sectional views of the airfoil. [Figure 19] Figures 15-18 show partial perspective views of the boom area of ​​the airfoil without the flap envelope, from two different viewing angles. [Figure 20] Figures 15-18 show partial perspective views of the boom area of ​​the airfoil without the flap envelope, from two different viewing angles. [Figure 21] Figures 15 to 20 are enlarged perspective views of the gaff region of the airfoil. [Figure 22] Figures 15 to 20 are enlarged perspective views of the boom area of ​​the airfoil. [Figure 23] Figures 15 to 20 are enlarged perspective views of the boom area of ​​the airfoil. [Figure 24] This is an enlarged perspective view of a detailed embodiment of the airfoil orientation control mechanism. [Figure 25] Figures 25a and 25b schematically illustrate the selective sail reduction of flaps with airfoils as shown in Figures 15 to 24. [Figure 26] This is a schematic plan view of the coordination of the rear mast / rear shaped member for mutual angle locking. [Figure 27] This is a schematic plan view of the coordination of the forward mast / forward shaped member to define the free range of angle of the forward flap. [Figure 28] The torsion of the rear flap of the airfoil in Figures 15 to 24 is shown in two plan views. [Figure 29] This shows an alternative structure for the aft mast. [Modes for carrying out the invention]

[0017] First, a first embodiment of the present invention will be described with reference to Figures 1 to 11.

[0018] a) General principles Referring to Figures 1, 2, and 3A–3D, the airfoil according to this embodiment has two aerodynamic profiles, both of which have adjustable incidence angles and adjustable relative camber angles. Hereafter, these will be referred to as the first flap or forward flap and the second flap or rear flap. They are indicated by reference numbers 100 and 200, respectively. They pivot on an axis defined by two masts 310, 320, as will be seen below.

[0019] At least one of these profiles has an asymmetric aerodynamic cross-section in the longitudinal direction (having a leading edge and a trailing edge). It may include, for example, a section called a symmetric aircraft airfoil, more preferably a NACA00xx standardized section, etc.

[0020] The relative angle of the second flap to the first flap is adjustable along the height, thus allowing for a washout of the second flap.

[0021] Figures 3A to 3D schematically show the various positions that the two flaps can take.

[0022] In this embodiment, the first flap 100 has one degree of freedom determined by pivoting around the longitudinal plane P of the airfoil (as defined by the airfoil structure described later), while the second flap 200 can be tilted relative to the forward airfoil by applying stress using a seat system, cylinder, or any other system.

[0023] Figure 3A shows the airfoil in a headwind position (arrow F) with the aft flap 200 positioned in its midline. The forward flap 100 is spontaneously oriented along the wind axis, with the aft flap aligned to it.

[0024] In Figure 3B, the aft flap is still held in a central position with respect to the structural plane of symmetry P of the airfoil, but the wind is coming from the port side. The forward flap 100 is biased by the wind and rotates counterclockwise (viewed from above) with respect to plane P to the stop angle position shown in the figure. At this position, the airflow (flow F1) along the windward side of the forward flap (the surface of the flap located upwind) splits into an internal flow F2a on the windward side of the aft flap and a flow F2b on the leeward side within the transition area between the forward and aft flaps, and flow F2b propagates through a vertical opening or slit L defined between the trailing edge 102 of the forward flap 100 and the leading edge 201 of the aft flap 200. Thus, in a particularly simple manner, without the need to specially structure the forward flap, the airfoil having two flaps according to the present invention can benefit from the effect of the slit and its improved aerodynamic yield.

[0025] In Figure 3C, the wind direction is the same as in Figure 3B, but the rear flap is biased to be inclined toward the wind relative to the plane P of the airfoil.

[0026] This configuration achieves an effect similar to that of a flexible airfoil filling (or camber).

[0027] Finally, in Figure 3D, we can see that the rear flap 200 has a difference between the inclination of its lower region 200' relative to plane P and the inclination of its upper region 200'' relative to plane P, for the torsional command which will be described in detail later. This torsion can give the airfoil a variable camber that helps improve its performance. More specifically, this change can generate an aerodynamic torsion of the airfoil (a change in the null lift angle along its length) to adapt to the wind gradient, or to offload the top of the airfoil, or even generate a reverse camber to increase the righting torque.

[0028] Naturally, the opposite phenomenon can be observed with a starboard wind.

[0029] According to one implementation modification, the forward flap 100 is not free, but it can be driven to conform to the same behavior as shown in Figures 3A to 3D.

[0030] According to the profiles of the forward flap 100 and the rear flap 200, more generally in terms of their lateral dimensions, the angular range in which the forward flap 100 can move freely (either freely or by command) is typically comprised of ±1° to ±15°.

[0031] b) structure The structure of the airfoil according to this first embodiment will be described in detail here with reference to Figures 4 to 11.

[0032] The airfoil comprises a rigid frame 300 formed by two cylindrical masts 310 and 320, which have a constant outer diameter and are rigidly connected to each other by upper and lower transverse structural members 330 and 340, respectively, forming a boom member and a gaff member. This structural framework rotates freely relative to the structure by bearings connected to the main mast. The members of this structural frame are formed of parts of, for example, metal or composite material, appropriately sized according to stress.

[0033] Here, in this embodiment, the forward mast 310 is self-supporting and does not have a shroud, but it should be noted that it is of course expected that all or some of the following components may be equipped: the mounting point being the top of the mast above the flap structure, the shroud, the stay, and the running back stay.

[0034] In this embodiment, since the thickness of the rear flap 200 is less than the thickness of the front flap 100, the rear mast 320 can have a smaller diameter than the diameter of the front mast 310.

[0035] A series of forward-shaped members 110 and a series (preferably the same number) of aft-shaped members 210 are attached to the forward and aft masts, respectively, and together the members describe an envelope of a symmetrical aerodynamic profile intended to form first and second flaps 100, 200, together with their respective envelopes 120, 220 (not shown in Figures 4 to 7). These envelopes 120, 220 are manufactured, for example, in the form of tension covers on their respective shaped members. In particular, aviation canvas or fabric of the type used in conventional sails, which is subjected to tension during hoisting, can be used.

[0036] In modified embodiments, although not shown, envelopes 120, 220, or at least one of them, can be discontinuous, that is, made from two or more envelopes of smaller heights that are substantially aligned along their respective flaps and separated by a limited height gap.

[0037] The shaped members 110 and 210 rotate and translate freely on their respective masts 310 and 320. These two degrees of freedom are provided by, for example, smooth bearings or ball bearings (not shown in Figures 4 to 7), which are intended to enable these movements while reducing friction and avoiding the risk of pinching.

[0038] In a particular embodiment shown in Figure 8, these bearings include two bearing members, 112a and 112b, respectively, which are enclosed within the upper and lower regions of the shaped member 110 and surround an opening 111 formed in the shaped member, allowing the associated mast 310 to pass through.

[0039] Generally, the height of the guide members is chosen to give the airfoil the most compact form possible once it is lowered, while minimizing the risk of friction and blocking.

[0040] As the shaped members translate along each mast, the two airfoils can be raised and lowered, and the sails can also be reduced, as can be seen below.

[0041] The vertical displacement of the shape members 110, 210 and their respective envelopes 120, 220 is carried out identically on both masts by creating a gaff section 340 in the form of a fixed member 342 firmly fixed to the masts 310, 320 and an elevator member 344 that can slide along the mast and to which the uppermost shape members (110a, 210a) of the forward airfoil 100 and aft airfoil 200 are rotatably fixed, and this sliding member 344 can be raised and lowered using a halyard 400, thereby driving each envelope, and each shape member 110, 210, respectively, in an gradual manner. This rotatable connection between the shaped members 110a, 210a and the part 344 ensures a secure connection that allows the upper end of the airfoil to translate together with the part, while enabling the freedom of movement of the forward flap 100 relative to the gaff 340 within the specified angular limits as previously described, and the freedom of movement of the rear flap 200, which is angularly biased at an incline as specified below.

[0042] In this embodiment, the halyard 400 is guided by an assembly of transmission pulleys (including a pulley 410 at the top of the fixing member 342 of the guff assembly 340) and passes through an opening formed in the central region of the fixing member 342 of the guff 340 to be attached to the central region of the sliding member 344. From the upper region of the airfoil, the halyard 400 enters the forward mast 310 through the opening 312 and then runs downward within the forward mast 310 (see Figure 11). The lower end of the halyard (not shown) can be operated manually or, in the case of the largest airfoil, using a motor (not shown).

[0043] Depending on the command applied to this motor, the airfoil can be raised and lowered over its entire vertical range, and also retracted, by positioning the sliding part 344 at a height lower than its maximum height.

[0044] The way in which the shaped components and the flaps that form their framework rotate is described in detail here.

[0045] In this embodiment, the forward flap 100 has a certain degree of angular freedom around its mast 310, as already described. However, in another embodiment, it has been found that it can be controlled by the main sheet or other control members.

[0046] Regardless of the wind incidence angle, the arrangement of the forward mast 310 relative to the center of the aerodynamic thrust of the flap 100 is such that the flap stops at an angle in either a clockwise or counterclockwise direction (depending on the wind incidence side), as shown in Figures 3B, 3C, and 3D.

[0047] As shown in Figure 5a, a smaller angle of stopping can be provided by providing a finger 114 that protrudes from the lowest shaped member 110b of the forward flap 100 and engages with the fan-shaped throat 332 on the upper surface of the boom 330.

[0048] A similar configuration can be provided between the uppermost shaped member 110a of the front flap and the lower surface of the sliding member 344 of the gaff 340.

[0049] Alternatively, the angular swing limitation of the forward flap 100 can be provided by acting between the mast 310 and the lower shaped member 110b (each to the uppermost shaped member 110a), or even by using a lanyard with one end attached to the rear region of the lowermost shaped member 110b and the other end attached to the boom 330. In this case, the corresponding configuration is provided between the uppermost shaped member 110a and the sliding member 344 of the gaff 340.

[0050] Referring to Figure 27, the configuration for limiting the angular mobility of the forward shaping member 110 relative to the forward mast 310 includes at least one longitudinal rib (in this embodiment, two opposing ribs 310a, 310b) provided on the mast 310 and capable of cooperating with a pair of longitudinal recesses 110a, 110b with a larger angular width formed in the bearing members 112a, 112b of the shaping member 110. The ribs 310a, 310b can be integrated with the mast or provided on skirts surrounding the respective mast bodies.

[0051] According to another modification, a transverse rail can be fixed to the boom 330, in which the cart can slide following the rear region of the lowest molding member 110b, and an equivalent (or different) configuration can be provided in the upper region of the airfoil.

[0052] As shown above, the aft flap 200 has a degree of freedom of rotation around its mast 320, but its angular position is driven at least in its lower region, and preferably in its upper region as well, so that the twisting of the flap can be controlled.

[0053] Furthermore, the angular position control of the flap 200 can also be provided at one or more intermediate height positions so that its camber can be adjusted locally in that manner.

[0054] In this embodiment, the rear flap 200 is driven by using a first control means to control the angular position of its lowest forming member 210b adjacent to the boom 330, and using a second control means to control the angular position of its uppermost forming member 210a adjacent to the sliding member 344 of the gaff.

[0055] Near the boom 330, particularly as shown in Figures 9 and 10, the angular position of the shaping member 210b is driven here using a cylinder 510, the cylinder body of which is mounted on a plate 332 fixed to the boom 330 and freely rotatable in a horizontal plane, its rod mounted around the mast 320 directly above the boom member 330 and articulated at the free end of a transmission arm 515 that is rotatably fixed to the shaping member 210b.

[0056] It is understood that by driving the length of cylinder 510, the angular position of the base of the rear flap is gradually driven, thereby increasing or decreasing the camber of the airfoil from one side or the other, depending on wind and navigation conditions.

[0057] To drive the upper region of the aft flap 200, a second cylinder 520 is provided, positioned substantially symmetrically to the first cylinder. The body of the cylinder is rotatably mounted on a plate 334, which is positioned opposite the first plate 332. The rod of cylinder 520 is articulated to a transmission member 525, which is swivelably mounted to the lower end of the mast 320 directly below the boom member 330. This transmission member 525 is manufactured as a single piece and forms two opposing transmission arms 525a, 525b positioned substantially laterally to the boom, with the rod of cylinder 520 connected to the free end of the first transmission arm 525a.

[0058] Two transmission lanyards 610, 620 are attached to the free end regions of the two transmission arms 525a, 525b, respectively. With the help of appropriate transmission pulleys 611, 621, these lanyards pass through the forward mast 310 toward its top and exit through an opening 312 provided for the halyard 400, where they are connected to a second transmission member 530, which is substantially identical to member 525 and is rotatably fixed with the shape member, and is positioned between the sliding member 344 of the gaff 340 and the uppermost shape member 210a.

[0059] In this way, the cylinder 520 is used to control the angular position of the uppermost shaped member 210a of the rear airfoil 200 from the boom region, thereby selectively creating a twist of the rear airfoil, and thus gradually changing the camber of the airfoil between the front flap 100 and the rear flap 200 over its height.

[0060] To enable guidance with the help of lanyards 610 and 620, a mechanism is provided for adjusting the length of the lanyards 610 and 620 between their mounting points on the respective transmission members 525 and 530, regardless of the height of the sliding member 344 of the gaff 340, including the retracted sail position.

[0061] For lightweight airfoils, this adjustment can be performed manually, for example, by a jamming cleat near the lower transmission member 525. In larger systems, an electric actuator, for example, is provided to selectively release and hold the lanyard in the area of ​​the transmission member 525.

[0062] Furthermore, cylinders 510 and 520 can be replaced with other devices suitable for the size of the airfoil system. In particular, for airfoils sized for light vessels, a lanyard system with jamming cleats can be provided, if necessary, without the aforementioned guide members, or with guide members or levers arranged in a different manner.

[0063] As shown above, the assembly formed by the rigid structure (masts 310 and 320, boom member 330, and gaff 340 fixing member 342) can be angle-adjusted (trimmed / relaxed) around the ship's axis by rotating the forward mast 310 itself.

[0064] In the first embodiment, this rotation can be implemented by a hollow shaft motor having a reduction gear (not shown) coaxially mounted to the base of the mast 310.

[0065] In a second embodiment, the command can be manufactured away from the mast by using a transmission such as a pulley 700 (possibly notched) connected via a belt, gearing, etc. to a control mechanism (manual, electric, hydraulic, etc.) fixed in the lower region of the mast 310 (see Figures 4 and 5). In a particular embodiment, as shown in Figure 24, the device for rotating the mast 310 comprises a gear motor 710 that engages with a gear 720 coaxial with the mast.

[0066] Finally, especially in the case of lightweight sector board type boats or small recreational boats, the sheet and tackle are simply installed, similar to the control of a conventional mainsail. Then, in the area of ​​the aft region of the boom member 330, the mooring is performed.

[0067] In either case, to ensure that the rigid frame, consisting of the two masts 310, 320, the boom member 330, and the gaff 340's fixing member 342, rotates as a whole during this angle adjustment, members 330 and 342 are mounted to the forward mast 310 so as to be rotatably fixed.

[0068] In summary, a double-flap airfoil is proposed in accordance with the present invention that automatically (without specific adjustments) benefits from the slit effect between the forward and rear flaps.

[0069] Furthermore, the airfoil according to the present invention can be lowered and retracted very easily by a single halyard controlled manually or by a motor.

[0070] More generally, the operation of airfoils (general orientation, camber, and camber changes) can be easily driven and automated by actuators.

[0071] In this regard, several sensors and an onboard computing center can be combined with this airfoil for this automation.

[0072] In particular, Harken, Pewaukee, Wisconsin, USA, has proposed an automatic sail control system that can be adapted to the airfoil according to the present invention by those skilled in the art.

[0073] Referring to Figures 12 to 14, a second embodiment of the airfoil flap according to the present invention is described here. In this second embodiment, each flap 100, 200 is constructed by retractably nesting a series of substantially rigid box-shaped members, 130, 230, each having a bottom (131, 231, respectively) and rising peripheral walls (132, 232, respectively), and each having a substantially U-shaped vertical cross-section (see Figure 13), such that each member is slightly smaller than the member directly below it and can occupy an open position or a position where it is enclosed, depending on the applied stress. Other vertical cross-sections that allow for the nesting of members can be considered.

[0074] Each bottom 131 of the shaped member 130 has an opening 133 through which the forward mast 310 extends. Similarly, each bottom 231 of the shaped member 230 has an opening 233 through which the rear mast 320 extends. Preferably, these openings are provided with guide rings or similar bodies in a manner similar to that shown in Figure 8 with respect to the shaped members from the first embodiment, for example. In this way, the masts 310 and 320 function as guides for each box to avoid pinching each other during the movement of each box relative to each other.

[0075] Furthermore, although not shown in the diagram, the two adjacent boxes are equipped with stopping mechanisms (flanges, rims, fingers, etc.) to prevent one box from being completely separated from the other.

[0076] In the lower region of the airfoil, the lowest boxes 130a and 130b are vertically translated and fixed to the boom member 330, while in the upper region of the airfoil, the uppermost boxes 130b and 230b are vertically translated and fixed to the sliding member 344 of the gaff 340.

[0077] In this way, the displacement of the sliding member 344 by the halyard 400 functions to pull up the airfoil by causing the boxes from the forward and aft airfoils to gradually unfold upward during this pull-up.

[0078] The descent is performed in the reverse direction, and the total height of the airfoil after descent is substantially equal to the height of one box.

[0079] As before, the sail can be retracted by positioning the sliding member 344 at an intermediate height above the boom 330.

[0080] The variable camber of the airfoil, as understood for the torsion of the rear flap 200, can be made possible by fabricating the box from a semi-rigid material that allows for some elastic deformation of the box between its bottom and its apex. Alternatively, or in addition to this configuration, some play can be provided between the base of one box and the open upper end of the box located directly below it.

[0081] The lower box 130b of the front flap preferably has a degree of freedom of movement within a preset angular range, in the same manner as the lowest shaped member 110b of the front flap 100 from the first embodiment. The upper box 130a of the front flap also has this degree of freedom, in the same manner as the uppermost shaped member 110a of the front flap 100 from the first embodiment.

[0082] Correspondingly, the lowest box 230b and the highest box 230a of the rear flap 200 are biased in the same manner as the lowest shaped member 210b and the highest shaped member 210a of the rear flap 200 in the first embodiment.

[0083] As shown in Figure 14, the forward mast 310 and the aft mast 320 preferably have a slight mutual inclination to maintain a substantially constant slit width L between the forward and aft flaps, despite the gradual reduction of the flap's cross-section from bottom to top (which is inherent to the nested structure).

[0084] In another embodiment, the trailing edge of the front flap can be aligned at least substantially with the leading edge of the rear flap, and a mechanism can be provided to move the boxes horizontally over a short distance once the boxes are separated from each other or at the end of the range of the separation operation in order to maintain an essentially constant slit width.

[0085] In yet another embodiment, the flap may be provided to consist of one or more airtight envelopes that can be inflated section by section or as a whole. In this approach, the airfoil can be cured in place for use. For example, the shape members 110, 210 can be consequently fitted by constraining each section of the airfoil with ribs that act as shape members. When inflated as a whole, the shape members are not sealed and are designed to allow air to pass perpendicularly along the flap.

[0086] Another embodiment of the present invention is described here.

[0087] In this embodiment, elements, parts, or components identical or similar to those in previous embodiments are given the same reference numerals whenever possible and will not be described again.

[0088] Referring here to Figures 15 to 24, the objective of this embodiment is to provide the airfoil with the ability to independently control (manually or electrically), raise, lower, and retract the forward and aft flaps, respectively, while maintaining the possibility of twisting the aft flap.

[0089] In this regard, it should be noted that, in the first embodiment, an elevator member 344 common to both the front and rear flaps is required to control the uppermost and lowermost shape members of the rear flap, as shown in Figures 9 to 11.

[0090] According to this embodiment, the forward and aft flaps can be independently controlled by their respective halyards 400A and 400B in terms of raising, lowering, and retracting the sails.

[0091] Both halyards are of the loop type, meaning no winding is required.

[0092] The halyard 400A for the forward flap 100 is driven by a first pulley 430A powered by a gear motor 420A, both of which are attached to a support structure 440 at the base of the forward mast 310 (see Figure 22). From this gear motor, the halyard 400A travels through the forward mast 310, exits through an opening with a pulley at the top of the forward mast, and is guided to the uppermost shaped member 110a of the forward flap 100 via another pulley and opening in the gaff 340. The halyard 400A is attached to the shaped member 110a and from there travels along the forward mast through a series of shaped members 110, and finally through multiple openings formed in 110b. From there, it is redirected by appropriate pulleys around the boom and heads towards the drive pulley 430A.

[0093] The halyard 400B for the aft flap 200 is driven by a second pulley 430B powered by a gear motor 420B, and is also guided through the forward mast 310, then along the top of the gaff member 340, and then downward within the member. It is attached to the uppermost shaped member 210a of the aft flap, and then passes through a series of openings formed in the subsequent shaped members 210, and finally 210b. From there, it is redirected aft by a suitable pulley around the boom and heads toward the drive pulley 430B.

[0094] It will be understood that by operating motors 420A and 420B individually, the forward and aft flats can be raised, lowered, and retracted independently of each other.

[0095] In order to enable twisting while allowing the aft flap to be raised to different heights, in this embodiment the twist is applied directly to the aft mast 320, rather than to the uppermost and lowermost shape members 210a, 210b of the aft flap, as in the first embodiment.

[0096] The torsional capability of the mast itself can be ensured by selecting a mast body material (typically a suitable composite material) that can withstand a given degree of torsion, or by providing an outer skirt around the mast body that can slide around the mast body and withstand the torsion.

[0097] Torsion control relies on a pair of cylinders 510, 520 located beneath the boom member 330, in a manner similar to that of the first embodiment. As shown in Figure 20, the first cylinder 510 can drive the bottom of the aft mast 320 through a first transmission plate 515 located beneath the boom member 330, contrary to the first embodiment. The plate 515 is directly connected to the lower end of the mast 320, which extends through the thickness of the boom, and induces its rotational motion in one or the other direction.

[0098] The second cylinder 520 can drive the top of the aft mast 320 via a control plate 525 having control arms 525a, 525b connected to the respective lanyards 610, 620 (not shown in Figure 20), just as in the first embodiment.

[0099] These lanyards travel through the forward mast 310 and connect to a transmission plate 530, which has similar transmission arms 530a, 530b and is firmly connected (at least in the rotational direction) to the top of the aft mast, as shown in Figure 21.

[0100] By controlling cylinders 510 and 520 in a direction that causes the same rotation at the bottom and top of the aft mast 320, the latter, along with its flaps as described below, can be adapted to a desired orientation according to navigational conditions.

[0101] By providing differential control of the cylinder, in addition to this orientation control, it is possible to provide torsion of the rear flap.

[0102] In modified embodiments not shown, angle control of the bottom and top regions of the aft mast 320 can be performed by motors acting on the respective mast regions via direct drive or appropriate gearing.

[0103] Referring to Figures 26 and 28, the coordination between the rear mast 320 and the shaped member 210 is shown.

[0104] Figure 26 shows that the mast 320 has a constant non-circular cross-section, and that two radially opposite longitudinal ribs 325 extend along the entire height of the mast.

[0105] Each of the shaped members 210 has a complementary shaped opening 211 having two diametrically opposite recesses 215 into which the respective ribs 325 engage (preferably in its bearing component or portion). In this way, the shaped members 210 and the aft mast 320 are locked together in the rotational direction, while allowing the shaped members 210 to slide along the mast for the purpose of raising, lowering, and retracting the sails.

[0106] Figure 26 illustrates how the torsion of the aft flap is performed, with cylinder 520 controlled to generate an angular shift of the top portion of the mast 320 (and thus the uppermost shape member 210a) over an angle α with respect to the longitudinal axis of the boat, while cylinder 510 is controlled to generate an angular shift of the bottom portion of the mast 320 over an angle β with respect to the same longitudinal direction. Thus, a torsion is generated, and the aft flip is the average angle that falls between these two angles with respect to the longitudinal direction.

[0107] It will be easily understood that the angle lock between the rear mast and the shaped member 210 can rely on a completely different non-circular shape.

[0108] Figure 29 shows a modified embodiment of the mast 320, which includes a main mast body 320a surrounded by a skirt or sleeve 320b that can rotate freely around the body 320a.

[0109] The material properties and thickness of sleeve 320b allow for fine-tuning of its torsional characteristics, achieving the same aft flap torsion as described above while maintaining the main mast body 320a with suitable rigidity.

[0110] It should be noted that a principle similar to that shown in Figure 28 can be used to limit the angular displacement of the forward flap relative to the forward mast 310, as shown in Figure 27. This can be achieved, for example, by providing a pair of ribs 310c, 310d on the forward mast 310 that cooperate with wider (angle-wise) recesses 110c, 110d provided on the shaped member 110 of the forward flap 100.

[0111] Of course, the present invention is by no means limited to the embodiments described above and shown in the drawings, and those skilled in the art will be able to see how many variations or modifications can be made thereto.

[0112] In particular, those skilled in the art will be able to imagine any combination of the various embodiments and variations described herein.

[0113] Furthermore, from the teachings in the above description, those skilled in the art will be able to see how to manufacture an airfoil having three or more flaps according to the same principle.

[0114] According to another variation, each flap or one of the flaps (typically the rear flap) can be realized in several parts, so that the angular offset of each part relative to the nearby ones helps to perform washout, particularly in the area of ​​the rear flap.

[0115] Furthermore, the single airfoil having two flaps according to the present invention can be advantageously equipped to any type of vessel, such as recreational boats, dinghies or light multi-hulled vessels, racing boats, container ships, and electric and sail-propelled mixed cruise ships to achieve fuel savings.

Claims

1. An airfoil propulsion system comprising a double airfoil (100, 200) mounted on a structure (300) whose angle is controlled by conditions on a substantially vertical axis, wherein the double airfoil comprises a forward flap (100) and a rear flap (200) separated by a slit (L), at least one of which is asymmetrical front to rear, and each flap comprises a series of shaped members (110, 210) distributed in height, the structure comprises a forward mast (310) and a rear mast (320) connected by a boom member (330) and a guff member (340), the shaped member (110) of the forward flap is traversed by the forward mast (310) and can rotate on an axis defined by the forward mast (310), and the shaped member (210) of the rear flap is traversed by the rear mast (320) and can rotate on an axis defined by the rear mast An airfoil propulsion system that can rotate around an axis, the structure can rotate on a rotation axis formed by the forward mast (310), each of the forward and aft flaps (100, 200) is provided with top members (110a, 210a) that allow each to slide independently from the other along the respective mast (310, 320), the airfoil propulsion system further comprises two halyards (400A, 400B) that allow the forward and aft flaps to be raised, lowered and retracted independently, and the forward mast (310) is provided with a configuration that defines an angular interval that allows the shaped member attached to the forward mast (310) to move freely around the forward mast (310) while allowing the shaped member attached to the forward mast (310) to slide along the forward mast (310).

2. The airfoil propulsion device according to Claim 1, wherein the forward mast (310) is configured to allow the shaped member to slide along the forward mast (310) while defining an angular interval in which the shaped member (110) attached to the forward mast (310) can move freely around the forward mast (310), and the rear mast (320) is configured to allow the shaped member to slide along the rear mast (320) while angularly locking the shaped member (210) attached to the rear mast (320) by the rear mast (320).

3. The airfoil propulsion device according to claim 1 or 2, wherein the configuration defining the angular interval comprises at least one rib (310a, 310b) on the forward mast (310) and corresponding recesses (110a, 110b) on each of the shaped members (110) attached to the forward mast (310).

4. The airfoil propulsion device according to claim 3, wherein the configuration defining the angular spacing comprises two opposing longitudinal ribs (310a, 310b) on a corresponding mast and two corresponding recesses (110a, 110b) on a shaped member (110) attached to the forward mast (310).

5. The airfoil propulsion system according to claim 1 or 2, wherein the aft mast (320) is rotatable and a controller can act on the bottom and top of the aft mast.

6. The airfoil propulsion system according to any one of claims 1 to 5, wherein each of the two halyards (400A, 400B) is provided with an independent drive configuration (420A, 430A, 420B, 430B).

7. The airfoil propulsion system according to claim 6, wherein the drive configuration is mounted on a support structure (440) at the base of the forward mast (310).

8. The airfoil propulsion system according to claim 7, wherein the two halyards are arranged to travel along the forward mast (310) or inside the forward mast (310).

9. The airfoil propulsion system according to any one of claims 1 to 8, wherein the two halyards (400A, 400B) are loop-shaped, thereby avoiding the need for winding.

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