WO2023094176A1

WO2023094176A1 - System of articulated fins for a boat

Info

Publication number: WO2023094176A1
Application number: PCT/EP2022/081559
Authority: WO
Inventors: Patrick Ballu
Original assignee: Exel Industries
Priority date: 2021-11-29
Filing date: 2022-11-10
Publication date: 2023-06-01
Also published as: FR3129651A1

Abstract

The present invention relates to a system of articulated fins for a boat (1) having a hull (2), the system of fins comprising at least two fins (10) having a respective end fastened to an element of the hull (2) of the boat (1), the two fins (10) being situated one on each side of a longitudinal axis of the boat (1), each fin (10) being intended to be completely submerged in a deployed position of the fin, each fin (10) also having a folded position in which the fin (10) is intended to come up against the hull (2) of the boat (1), and each fin (10) having operating means configured to move the fin (10) between the folded position and the deployed position, and vice versa. The fin (10) has a web and a working portion fastened to the web.

Description

Articulated flipper system for boat

The present invention relates to the field of boats, in particular offshore sailboats, and relates to a system of articulated fins that can be moved between a folded position and a deployed position, and vice versa.

STATE OF THE ART

The present invention thus lies in the field of boats, in particular offshore boats, such as tall sailing ships or cruise ships designed to travel long distances. As is known, this type of boat is configured so that its upper deck is located high above the water and that all of its decks remain as horizontal as possible, in particular with a list close to zero degrees. The objective is indeed to ensure the comfort and safety of passengers during periods of navigation that can last several weeks.

Thus, these boats are generally equipped with transverse fins, located at the rear, whose bearing or plunging incidence is automatically corrected in order to create a couple, whose axis is longitudinal, in order to compensate for the heeling effect caused by the side wind.

In addition, we are also trying to improve the speed of boats, especially large ones. To this end, foil systems have been developed. Thus, the newest competition sailboats are fitted with large foils, either sliding in curvilinear slots in their hulls or hinged above the waterline, with the aim of lifting their hull completely out of the water and accelerating considerably. their speed. In operation, these large foils are partially submerged and partially gliding on the surface of the water. These foils are very bulky, whether in the deployed position or in the folded position. Such foils are also vulnerable, even dangerous, in navigation, in the event of encounter and impact with any drifting object. Their size also makes them difficult to maneuver in ports, and ill-suited to offshore leisure sailboats, because they are difficult to pilot and above all to maneuver, especially with a small crew. To be effective, these foils also require the structure and contents of the sailboat to be considerably lightened, in order to allow it to come out of the water almost completely.

These constraints are not compatible with blue water cruising sailboats, comfortable, autonomous, very solid in all wind or sea conditions, and generally implemented by a reduced crew. Indeed, this type of offshore cruise ship is necessarily quite heavy, because it must also carry a lot of equipment such as furniture, generators, large capacity batteries, heating and air conditioning systems, fridge-freezers , dishwashers or laundry machines, etc.

Some offshore cruising sailboats are nevertheless equipped with linear foils, emerging transversely from the underside of their hull. These foils, in the form of straight blades, contribute to accelerating the speed of the sailboat, by sliding on the surface to get the bow of the sailboat out of the water, in order to reduce its resistant torque and its wetted surface. But the piloting of these sailboats is delicate, because of the disturbances of the waves on the foils, which moreover cause a lot of spray. In addition, the incidence of these linear foils is not adjustable, because they are constrained by the slot in which they move to exit or enter the hull. Finally, as these foils are almost perpendicular to the longitudinal axis of the boat and to the direction of travel, they remain particularly vulnerable to drifting objects, encountered in navigation, which can remain snagged (nets, ropes, branches, plastic films, buoys, etc.) or cause damage to the hull in the event of a violent impact.

It should also be noted, with regard to boats of the offshore sailboat type, driven by the force of the sail, that the latter have a high center of sail, in particular located at 30%-40% of the height of their mast. This has several effects on the look of these offshore sailboats. Firstly, this high center of sail contributes to heeling the boat, which reduces the wind force, despite the compensating effects of the keel. When heeling, the center of the sail moves downwind, which also helps to pull the boat upwind, and to make it fiery, as the saying goes; this tendency must be compensated by the balancing of the sails and by actions on the rudder, which therefore slows down the boat. Finally, this high point of sail of offshore sailboats also causes the sinking of its bow, which generates violent braking in the swell or in the waves, especially when the speed is not buoyant, which delays or compromises its possible ability to plane, i.e. to "hover", and therefore to accelerate beyond its theoretical speed limit.

The present invention aims to remedy at least in part the aforementioned drawbacks and thus to allow an offshore boat, in particular an offshore ocean-going sailboat, comfortable, safe and very well equipped internally, to significantly increase its speed, in particular from 2 to 8 additional knots, while reducing its list and its drift at non-carrying speeds, and while facilitating its piloting, despite a reduced crew.

In this context, the system proposed in this document makes it possible to reduce the list to increase the sailing force, to increase the anti-drift surface to improve, in other words reduce, its heading at close quarters, to better pass in the waves lifting the bow of the sailboat and taking its bow out of the water, to reduce its tendency to pitch on each wave, to trigger any lift-off sooner, thanks to maximum support on the flat shape of the back of the hull, and to make the speed of the boat more stable by reducing the effect of upwind (ardence), or felling (softness) at all speeds, downwind or downwind.

PRESENTATION OF THE INVENTION

More specifically, the subject of the invention is a system of articulated fins for a boat having a hull, the system of fins comprising at least two fins having a respective end fixed to an element of the hull of the boat, the two fins being located either side of a longitudinal axis of the boat, each fin being intended to be fully immersed in a deployed position of the fin, each fin also having a folded position in which the fin is intended to come against the hull of the boat, and each fin having operating means configured to move the fin between the folded position and the deployed position and vice versa.

In addition, each fin comprises a core, in particular made of titanium, and a working portion fixed to the core by means of fixing means, the core being fixed integrally to the maneuvering means. This makes it possible in particular to have a fin core made of very hard material, such as titanium, and a working portion which envelops it, which can be made of resistant synthetic material or carbon, lighter than the material constituting the core. . The working portion may or may not be in one piece.

Each fin has a front edge, in other words oriented towards the bow of the boat, which can in particular be curved backwards, so as to give the fin the shape of a shark's or dolphin's pectoral fin. This shape allows less shock and less risk of a drifting object, such as a net, catching and getting stuck, because the curved shape towards the rear of the front edge facilitates the evacuation of such objects which slide, if necessary, along the front edge of the fin and are evacuated backwards.

According to an advantageous embodiment, the fastening means are fusible; for example, they may be pins or screws or bolts configured to provide a fuse function.

The fins allow in particular to raise the bow of the boat, so as to get it out of the water, to improve the speed of the boat, while ensuring its stability and that of its course.

According to one embodiment, each fin has a shape adapted to match a predefined shape of the hull of the boat, in the folded position, in which the fin is pivoted to come against a lateral side of the hull of the boat.

Preferably, each fin comprises an anti-heel portion having an airfoil and an anti-drift portion, the anti-heel portion being substantially vertical and the anti-drift portion being substantially horizontal in the deployed position of the fin.

According to one embodiment, for each fin, the maneuvering means comprise pivoting means comprising at least one pivot, adapted to pivot the fin around a pivot axis, between the folded position and the deployed position and vice versa.

Advantageously, the pivoting means are configured to be fixed to a lower part of the hull, between the keel and the chine of the boat.

This ensures that the fins always work while submerged, when in the deployed position.

In particular, for each fin, the maneuvering means comprise means for moving the pivot axis of the fin, configured to modify the incidence of the fin.

The fin system according to the invention may also include control means configured to keep the anti-heel portions of the fins horizontal.

In particular, for each fin, the fastening means are fusible and can be configured to allow separation of the working portion vis-à-vis the core, automatically or in a controlled manner.

Each fin may in particular comprise a cable connecting the working portion to the core, the cable being configured so that, when the working portion is separated from the core, the cable tows the working portion to the side and/or at the back of the boat while sailing.

According to one embodiment, each fin comprises locking means for locking an angular position of the fin between a plurality of positions including at least the folded position and the deployed position.

According to one embodiment, the fin system according to the invention may comprise backup means configured to automatically move each fin to the folded position.

The present invention also relates to a boat, in particular an offshore sailboat, comprising a hull having a flat rear portion, and a system of fins as briefly described above, the system of fins being fixed to the hull of the boat.

According to one embodiment, the boat comprises a recess and/or a rabbet adapted to house in a recess in the hull at least part of the thickness of each fin in the folded position.

According to the invention, the boat may also comprise means for producing electrical energy connected to the articulation and pivoting device, and configured to produce electrical energy when the boat is at anchor.

According to one embodiment, the fin system of the boat comprising a pair of front fins and a pair of rear fins, the front fins have a bearing effect and the rear fins are configured in such a way that, when the port front fin is in deployed position and the starboard forward fin is in the folded position, the wind coming from the starboard side, then the starboard aft fin is in the deployed position and its angle of attack is adjusted so as to be plunging, the port aft fin being in the folded position or in the deployed position with a bearing angle, and, conversely, when the starboard front fin is in the deployed position and the port front fin is in the folded position, the wind comes from the port side, then the port rear fin is in the deployed position and its angle of attack is adjusted so to be plunging, the starboard aft fin being in the folded position or in the deployed position with bearing incidence. This improves the anti-listing function of the rear fin which is upwind and tends to "press" the rear of the boat and thereby make it easier to turn the boat up, and it improves the lift of the front fin, which is downwind.

According to one embodiment, the boat having a waterline length, the respective incidence of the fins is configured to raise the bow of the boat, in particular 1% to 3% of the waterline length of the boat.

According to one embodiment, the fin system comprising a pair of front fins, the pivot axis of the front fins is pinched forwards, that is to say that the pivot axes of the front fins on both sides sides of the longitudinal axis of the boat are concurrent forwards. This improves the anti-drift function of the front fins: downwind, only one front fin is deployed; then, the pinch makes the anti-drift function is improved.

Advantageously, the fins, which can be connected to the keel, are configured to rest on the bottom in a grounding situation of the boat. An advantage of the invention thus lies in its use in the event of partial or total grounding, in particular at low tide, while leaving the boat horizontal. Indeed, the fins then provide grounding support, while leaving the boat, which rests on the fins resting on the bottom, in a substantially horizontal position.

Advantageously, the fins are configured to be deployed at anchor, the system comprising at least one nitrogen ball connected to the articulation and pivoting device and configured to dampen the pivoting movements of the fins due to the backwash. An advantage of the invention thus lies in its use at anchor. Indeed, the fins in the deployed position dampen, or even stop, the roll due to the undertow in fairground anchorage, by breaking any natural frequency.

According to one embodiment, the fin system of the boat comprising a pair of front fins, the front fins generate a center of thrust participating in a lifting of the bow of the boat located forward of a center of flotation of the boat, in particular located from 5% to 20%, for example from 8% to 10%, of the waterline length of the boat, forward of the boat's center of flotation. A positive effect is thus obtained when heeling the boat: the center of thrust generated by the front fins being forward, a pitch-up effect is generated and compensation for the softness of the boat is generated.

PRESENTATION OF FIGURES

The invention will be better understood on reading the following description, given solely by way of example, and referring to the accompanying drawings given by way of non-limiting examples, in which identical references are given to similar objects. and on which:

There is a schematic representation of a fin system according to the invention, mounted on a boat, seen in section from the rear of the boat.

There shows a schematic representation of the fin system according to the invention, according to an example comprising a pair of auxiliary fins, seen from below.

There shows a schematic representation of the fin system according to the invention, according to another example comprising a pair of auxiliary fins, seen from below.

There is a schematic representation of the attachment and the mechanical articulation of a fin on a hull element of the boat, according to one embodiment.

There is a partial schematic representation of a longitudinal section of a fin according to an example of a fin system according to the invention.

There is another schematic representation of a longitudinal section of a fin according to an example of a fin system according to the invention.

There shows the integration of part of the working portions of fins in the folded position in recesses arranged in the thickness of the hull of the boat.

It should be noted that the figures expose the invention in detail to enable the invention to be implemented, said figures can of course be used to better define the invention if necessary.

DETAILED DESCRIPTION OF THE INVENTION

There shows a representation, in vertical section, of an example of a system of fins 10 (or "fins" in English) articulated according to the invention, mounted on a boat 1. The system of fins 10 comprises, in this first embodiment , a pair of fins 10 fixed to the hull 2 of the boat 1, laterally, to port and to starboard respectively, and following the shape of the hull 2 when they are folded upwards, in other words when the fins 10 are pivoted against the side flanks 21 of the hull 2 of the boat 1, in the direction of the deck 3 of the boat 1. In addition to this pair of fins 10, called main fins or front fins, it can be provided, according to particular embodiments, a pair of additional fins, comprising two auxiliary fins, also called rear fins, 50 at the rear, also located on either side of a longitudinal axis D of the boat 1. In particular, the auxiliary fins 50 are fixed to the hull 2, close to rudders 6, i.e. just in front of rudders 6, as on the , or, preferably, just aft of the rudders 6, as in the . The auxiliary fins 50 are in principle of smaller dimensions than the other fins 10, and also match the shape of the hull 2 in the folded position.

Preferably, the shape of the

fins

10, 50 is rounded so as to reduce the intensity of possible shocks with floating objects, as will be described in more detail below. The rounding is visible on the , there and the . Thus, at least the front edge of each

fin

10, 50 is curved backwards, like the pectoral fins of dolphins or sharks.

With reference to the , there is shown an embodiment with a single pair of fins 10, consisting of a pair of front fins 10. In this vertical sectional view seen from behind, the port fin 10 is in the deployed position while the starboard fin 10 is in the retracted position, in other words in the rest position. As can be seen on the in particular, the fins are configured to be completely submerged, at least when they are in the deployed position, like the port fin 10 on the or like all of the

fins

10, 50 in FIGS. 2 and 3. The

fins

10, 50 in the deployed position extend mainly in a transverse direction with respect to a longitudinal axis D of the boat 1.

According to the embodiment shown in , housings 19 of reduced dimensions, which will be described in more detail below, are provided in the hull 2 to house a device for fixing and articulating each fin. The attachment and articulation device comprises in

particular means

31, 32, 33, 34, 35 for maneuvering the fins 10, which are described in detail below.

With reference to the embodiment of the , as can be seen in particular with regard to the port fin 10, in the deployed position on the , each fin has a so-called anti-drift portion 101, configured to penetrate the water substantially vertically, in other words orthogonally to the surface of the water when the boat is sailing. The anti-drift portion 101 forms an angle close to a right angle with a contiguous portion and extending to the end of the fin, called the anti-heel portion 102. The anti-heel portion 102 has a bearing surface able to lean in the water and under the surface of the water to "carry" the boat and in particular lift the bow of the boat. In other words, the front fins 10 prevent the bow of the boat 1 from diving. In particular, the front fins 10 can make it possible to lift the bow of the boat 1 by 1% to 3% of the waterline length of the boat 1. In particular, the front fins 10 generate a center of thrust participating in a bow lift of the boat 1 located forward of a center of flotation of the boat 1, on each side of the longitudinal axis D of the boat 1, in particular located from 5% to 20%, for example from 8% to 10%, of the length boat flotation 1.

Figures 4, 5 and 6 show an embodiment in which a plurality of pins 12 make it possible to secure the fixing of the working portion 100 of each fin 10 on a core 11, in particular metallic. It should be noted that this structure according to which each fin 10 comprises a core 11 on which is fixed, in particular via pins 12, a working portion 100 is a preferred embodiment.

With reference to the embodiment shown in Figures 4, 5 and 6, the pins 12 are configured in particular to guarantee the fixing of the working portion 100 on the core 11. According to one embodiment, in the event of an impact in a direction corresponding substantially to the longitudinal axis D of the boat 1, and therefore substantially orthogonal to the direction in which a fin 10 extends in the deployed position, if the intensity of the impact exceeds a predefined threshold, the pins 12 are configured to release and allow the separation of the working portion 100 vis-à-vis the soul 11. In this case, a cable 13 is provided to tow the working portion 100 on the side and / or at the rear of the boat 1 , so as to allow recovery and repair of the fin.

According to one embodiment, when the pins 12 thus act, like fuses, by releasing and allowing the separation of the working portion 100 vis-à-vis the core 11, a spring can be provided, fixed to the core 11 or to the shell 2, compressed by default when the working portion 100 is nominally fixed to the core 11, the spring decompressing and therefore pushing back the working portion 100 so as to move it away from the shell 2 of the boat 1 so as to avoid any impact between the working portion 100 and the hull 2 during separation. The description of FIGS. 4, 5, 6 is valid, mutatis mutandis, for the rear fins 50, if any.

As shown on the , the fins 10 of the fin system according to the invention are fixed to the hull 2, clearly below the water level when the boat 1 is sailing, and articulated by means of a fixing and articulation device fixed to a structural element of the hull 2. This applies to the front fins 10 visible in Figures 1 as for the rear fins 50 visible in Figures 2 and 3.

Preferably, the fins 10 are attached to the hull 2 between the bilge and the keel 5, as shown in the . It is specified that by keel is meant, in the context of the present, the lowest axial part of the boat 1. The keel 5 can present, as on the , a ballast which extends it axially downwards, so as to lower the center of gravity of the sailboat.

In particular, the

fins

10, 50 are fixed to the hull 2, on either side of the longitudinal axis D of the boat 1, which passes through the keel 5, the fixing and articulation device of each fin 10 being located in the housing 19 arranged in the hull 2, above the keel 5 and close to the latter. For example, the

fins

10, 50 are fixed substantially halfway between the keel 5 and the side chine of the hull 2 of the boat 1, on each side.

The housing 19 of each fixing and articulation device is designed so as not to occupy any useful volume and is preferably located under the interior floor of the sailboat, as on the . Each housing 19 is further insulated by a waterproof reinforcement casing 191; only the working portion 100 of each front fin 10 thus preferably protrudes relative to the hull 2 when it is in the deployed position. As a variant, it is possible to provide, for the housings 19, a shape of a well profiled half-bulb, in particular protruding from the shell 2, to house therein part of the fixing and articulation device.

The

fins

10, 50 work, as already indicated, always entirely below the surface of the water when they are in the deployed position.

In addition, thanks to the remoteness of the

fins

10, 50 vis-à-vis the surface of the water, in depth, any cavitation generating a loss of lift is avoided, and no spray is generated. Thus, by tending to maintain the anti-listing portion 102 parallel to the surface of the water, the underwater lift produced mainly by the anti-listing portions 102 of the fins 10 is maximized, since they are not disturbed by the effects waves or swell.

In addition, the anti-drift portions 101 of the

fins

10, 50, corresponding to the substantially vertical part of the fins 10 in the deployed position, form a substantial anti-drift surface and thus provide an anti-drift function. Thus the anti-drift portion 101 of each fin 10 contributes to stabilizing the course of the boat 1.

According to one embodiment, provision may be made for the anti-drift portion 101 of each front fin 10 to form an angle pinched forward equivalent to the natural drift of the hull 2, so that the boat tends to move forward strictly according to the longitudinal axis D of its hull 2, which notably improves its upwind performance. In other words, the pivot axes X of the front fins 10 then form an angle concurrent with the front of the boat 1.

The device for fixing and articulating the

fins

10, 50 comprises maneuvering means 31, 32, 33, 34, 35 of the

fins

10, 50. The maneuvering means comprise pivoting means for pivoting the

fins

10, 50 about a pivot axis X substantially parallel to the longitudinal axis D of the boat 1. Each fin 10 can in particular move, by this pivoting, between an extended position and a folded position, and vice versa.

In the folded position, the

fin

10, 50 comes against the lateral side 21 of the shell 2, the shape of which it matches. On the other hand, in the deployed position, the fin 10 extends in a mainly transverse direction with respect to the longitudinal axis D of the boat 1. The working portion 100 is completely submerged and the anti-listing portion 102, whose surface of lift, is substantially horizontal, in other words parallel to the surface of the water, while the anti-drift portion 101 is substantially vertical, in other words orthogonal to the surface of the water.

The pivot axis X, substantially parallel to the longitudinal axis D of the boat 1, can be moved slightly downwards or upwards, as shown in the examples of Figures 5 and 6, to allow the angles and directions to be adjusted. respective according to which the anti-drift portion 101 and the anti-heel portion 102 extend into the water.

In particular, it is thus possible, by varying the location of the pivot means and the direction of the pivot axis X, to adjust the incidence of the anti-heel portion 102 relative to the horizontal or relative to the orthogonal to the side of the boat 1. To this end, for each fin, the maneuvering means comprise means for moving the pivot axis X of the fin 10. These means for moving the pivot axis X may for example consist into bearings 36 articulated via means 33 for axial displacement of the bearing, which may comprise a motor coupled to an endless screw or cylinders, as shown in the and the .

According to one embodiment, when the fin system comprises front fins 10 and rear fins 50, the incidence of the front fins 10 can preferably be adjusted as being load-bearing. The incidence of the rear fins 50 is then adjusted correspondingly, depending on the direction of the wind and therefore the extended or folded position of the port and starboard front fins. Thus, when the wind comes from the starboard side, the port front fin 10 is in the deployed position and the starboard front fin 10 is in the folded position. The forward fin 10 on the port side, which is to leeward and in the deployed position, has an angle of incidence making it load-bearing. Therefore, the starboard rear fin 50, which is upwind, is deployed and has a plunging incidence, while the port rear fin 50 is in the folded position or in the deployed position with a bearing incidence. The starboard aft fin 50, which is upwind and in a deployed position, with a plunging incidence, thus contributes to favoring the pitching up of boat 1 by pressing the boat on the water and also participates in the anti-listing function.

Of course, the configuration is reversed when the wind comes from the port side.

It is further noted that the front 10 and rear 50 fins can be, in the event of a tailwind, all deployed and with an incidence set to be buoyant or, alternatively, with regard to only the rear fins 50, with an incidence set to be dips, so as to "press" the boat on the water and thus facilitate planing.

According to one embodiment, sensors are provided for measuring the stresses exerted on the structure of the boat 1, for example sensors measuring the intensity of a force exerted on the shrouds. Therefore, automatic or manual-triggered safeguard means may be provided for moving one or

more fins

10, 50 which were in the deployed position to the folded position, in the event of an effort exceeding a predefined intensity threshold or in the event of heel exceeding a predefined limit heel threshold. In addition, the safeguard means can allow a modification of the incidence of the

fins

10, 50 in the deployed position in order to make them more or less buoyant or more or less plunging.

With reference to the , provision is made, according to one embodiment, for a possible recess 23 and/or a rabbet 22 arranged in the lateral side 21 of the hull 2, corresponding to a recess provided in the side of the hull 2 of the boat 1 , on each side, so as to hide in the profile of the hull 2, whose shape it exactly matches, at least a portion of the thickness of each

fin

10, 50 in the folded position, to facilitate its passage through the water and not to cause disruptive spray during navigation.

As shown in the , it is further provided in particular that the length of the fins 10 is limited so that, in the folded position, they preferably do not protrude from the deck 3, or at least not from the railing 4 or the lifelines.

Still with reference to the , it should be noted that the

fins

10, 50 in the deployed position allow the boat 1 to be accelerated and stabilized. incidence of the fins 10 which can in particular be adjusted, as described below, makes it possible to raise the bow of the sailboat, in particular 1% to 3% of the waterline length of the boat 1, which reduces the wetted hull surface 2 and the resistant torque of the sailboat, thus improving its passage in the swell and the waves, by limiting the effects of pitching, and makes it possible to trigger its planing more quickly, if necessary, by pressing it on the back of its hull 2, which is preferably quite flat.

The

fins

10, 50 also reduce the list and contribute to increasing the sailing force, therefore the speed of the boat 1, through the anti-listing function ensured by the anti-listing portion 102 of each fin.

Similarly, the auxiliary fins 50, in other words the rear fins 50 visible in Figures 2 and 3, optional, located at the rear of the hull 2, and preferably smaller than the pair of front fins 10, in other words main , already described in detail with regard to the , can also contribute on the one hand to stabilizing the course, by making the sailboat neither soft nor hot, on the other hand to counterbalance the list, and also to trigger the planing of the boat more quickly, if necessary. For example, by adjusting their angle of attack so that it is negative, in other words plunging, by means of means for moving their pivot axis X, it is possible for the auxiliary fins 50 to contribute to leaning the sailboat more aft of its hull 2, thus facilitating its possible lift-off.

The core 11 already briefly described above is in particular metallic, for example titanium. Core 11 forms the "core" of each fin. The core 11 is thus the

fin element

10, 50 which is pivotally mounted. The core 11 thus has a pivot axis X substantially parallel to the longitudinal axis D of the boat 1. In the case where the structure of the

fin

10, 50 does not include a core, the fin 10 being directly articulated by means of a fixing and articulation device, the fin 10 comprises the pivot axis X.

The pivot axis X, already introduced previously, is achieved for example by means of two pivots respectively at the front and at the rear of the core 11, as shown in . With reference to the and at the , the core 11 comprises an elongated main body outwardly relative to the shell 2, substantially orthogonal to the pivot axis X. According to one embodiment, the core 11 also comprises an inner protrusion 110 extending inside the shell 2, in the housing 19 housing the fixing and articulation device. This inner protrusion 110 can receive a jack, or a motor 32, or an operating screw, or gear teeth, for example.

According to one embodiment, the

fin system

10, 50 comprises locking means 35 for locking each

fin

10, 50 in the deployed position or in the folded position, respectively. These locking means 35 make it possible to relieve the pivoting means and can have several locking positions between the two extreme positions which are the deployed position and the folded position of the

fins

10, 50. According to one embodiment, for each locking position , the locking means 35 form a flexible stop, in other words damped, that is to say for example an elastomeric stop or a stop connected to a nitrogen ball connected to a hydraulic circuit of the maneuvering means. This limits the forces on the hull and improves the comfort and flexibility of the fin system.

The core 11 can thus be immobilized by locking means 35 in several positions, including at least the folded position and the deployed position while sailing.

According to one embodiment, control means are also provided, for example gyroscopes, to maintain horizontal, that is to say parallel to the surface of the water when the boat is sailing, the anti-listing portions 102

fins

10, 50, so that they remain well submerged, parallel to the surface of the water, whatever the heel of the sailboat.

According to one embodiment, to adjust the incidence of the fin, in particular of the anti-heel portion 102, an articulated bearing 36 may be provided on which each pivot, front and rear, is mounted. Each articulated bearing 36 then makes it possible to translate the pivot axis X in a slot, in particular vertical, and substantially perpendicular to the portion of the shell 2 where this articulation is located, for example by means of a jack or a screw. , as shown in Figures 5 and 6. The angle of incidence of the

fin

10, 50 can thus be adjusted between different positions in which the incidence is respectively positive, in other words bearing, neutral, or negative, in other words plunging . In this way, the pivot axis X of the

fins

10, 50 can be moved.

As can be seen on the , there and the , each

fin

10, 50 has a rounded shape, curved backwards. In other words, the horizontal profile of each

fin

10, 50 has a shape, for example an arc of a circle, in the substantially horizontal plane in which the anti-heel portion 102 extends, the arc of a circle being oriented towards the rear of the boat 1. In the preferred embodiment, at least the front edge of the anti-listing portion 102 has this curvature. Preferably, the rear edge of the anti-heel portion 102 has a curvature substantially parallel to or greater than that provided on the front edge.

The curved shape towards the rear of the front edge of the fin, in particular of its anti-heel portion 102, makes it possible not to let any drifting object cling while sailing, such as plastic bags, branches, seaweed, ropes, nets, buoys etc.

According to one embodiment, the anti-heel portion 102 also has a streamlined shape, like an airplane wing, so as to improve its lift.

The working portion 100 of the

fin

10, 50 is preferably made of very resistant synthetic material, for example carbon, in particular lighter than the metal core 11 so as not to unnecessarily weigh down the sailboat. In particular, at least the anti-heel portion 102 is made of very resistant synthetic material, for example carbon.

The working portion 100 partially, or even completely, envelopes the core 11, in particular metal, to which it is fixed by the pins 12 visible on the , there and the notably. The pins are configured to improve the security of the attachment of the working portion 100 to the core 11. As described above, in the event of a violent impact with a drifting object, the pins 12 can assume a fuse function and allow the separation of the working portion 100 vis-à-vis the web 11.

In practice, to move a

fin

10, 50 from the folded position to the deployed position, it is possible in particular, first of all, to unlock it by actuating the locking means 35 in this direction, then to give it a zero or slightly negative impact to facilitate its descent, by means of a displacement of the pivot axis X. Then, the fin is pivoted, by means of the pivoting means, to the deployed position. The

fin

10, 50 is then locked in the desired deployed position, via the locking means 35, so as to inhibit the pivoting, then it is given a desired impact, positive neutral or negative.

Conversely, to move a

fin

10, 50 from the deployed position to the folded position, it can be given zero impact, then unlock it, then possibly give it a slight positive impact in order to facilitate its ascent. Finally, it can be pivoted to its folded position before locking it in this position. To facilitate folding, a return spring 320 may be provided which rests for example on the inner protrusion 110 of the core 11, as shown in the .

Another advantageous use of the fin system according to the invention resides in a situation where the boat is anchored.

In the deployed position, one or

more fins

10, 50 ensure the boat's stability when anchored. By breaking any natural frequency of oscillation of the boat 1, the system of fins makes it possible to dampen, or even stop, the roll due to the backwash.

According to this embodiment, there is also provided at least one nitrogen ball connected to the hydraulic means for maneuvering the

fins

10, 50 of the fin system and configured to dampen any movement of the

fins

10, 50, in particular when they are used at anchor, or, when sailing, to absorb the shock of the waves. In this case, the pivoting means of the attachment and articulation device connecting each

fin

10, 50 to the hull 2 have a degree of freedom configured so that the

fin

10, 50 can pivot under the effect of the backwash, then that it is in the deployed position, the pivoting being damped by said nitrogen ball.

According to another implementation of the fin system according to the invention, the fins 10 are used, so that they rest on the bottom in the event of total or partial grounding. Thanks to the fins 10, in such a grounding situation, the boat is kept substantially in a horizontal position.

According to an embodiment not illustrated, the fins 10 are fixed to the keel, in particular on either side of the ballast of the keel 5. In this case, the keel 5 is considered to be part of the hull of the boat 1. In this embodiment, the fins 10 are deployed on either side of the keel 5 (which then forms part of the hull 2 of the boat 1) and provide the anti-heel and anti-drift stabilizer function described above. In addition, the fins 10 then perform the stabilizing function at anchor to counter the roll due to the backwash in a more advantageous way because they are less cumbersome than when the fins are fixed to the hull 2 at a distance from the keel 5.

On the other hand, all or part of the means for maneuvering the

fins

10, 50, which combine the means for moving the pivot axis X and the means for pivoting each

fin

10, 50, can be manual, or hydraulic, comprising hydraulic cylinders 32 and/or rotary motors, or electric, comprising screw-nut assemblies, which can be coupled to a return spring 320, and/or a worm screw 310 mounted on teeth of gear or a rotary motor 31, or tires, for example. Preferably, the maneuvering means are controllable, or at least activatable, preferably remotely by means of electric buttons that can be controlled from a cockpit of the boat. According to one embodiment, the various successive means for maneuvering the

fins

10, 50 are controlled automatically, by means of a computer or a programmable automaton for example.

Alternatively or in addition or as a degraded mode, manual auxiliary maneuvering means can be provided, such as a winch handle, a manual hydraulic pump, etc. to ensure the displacement of the pivot axis X and/or the pivoting of the

fins

10, 50.

According to one embodiment of the invention, there is also provided an energy recovery device suitable for producing electrical energy from the kinetic mechanical energy produced by the forces applied by the water on the fins. 10, 50 fin system submerged.

In particular, at anchor, the

fins

10, 50 can be in the deployed position, as already described, to ensure the stability of the boat. In this configuration, the swell generates a pendulum movement of the

fins

10, 50 around their pivot axis X of the pivoting means of the fixing and articulation device which connects said

fins

10, 50 to the hull 2 of the boat 1. The energy recovery device is connected to the pivoting means and transforms the kinetic mechanical energy corresponding to the pendulum movement into electrical energy. For example, the kinetic mechanical movement is taken up by a cylinder and transferred to an alternator which generates electrical energy.

The electrical energy thus produced can be routed, for example, to an electrical system of the boat 1 comprising, for example, a voltage converter and a battery, the electrical energy being used to recharge the battery.

Thus, according to one embodiment, the means for maneuvering the

fins

10, 50 comprise a hydraulic maneuvering jack. A three-way valve is then provided to switch between an operating position and a position for producing electrical energy in which each side of the hydraulic operating cylinder is connected to an element such as a piston, to generate electricity. For example, on each side of the hydraulic maneuvering cylinder, there can be provided a respective electric motor or a respective hydraulic motor which drives an alternator adapted to generate electrical energy when the hydraulic maneuvering cylinder is moved, at anchor, due to of the surf.

Claims

Articulated fin system for a boat (1) having a hull (2), the fin system comprising at least two fins (10, 50) having a respective end fixed to a member of the hull (2) of the boat (1) , the two fins (10, 50) being located on either side of a longitudinal axis (D) of the boat (1), each fin (10, 50) being intended to be completely submerged in a deployed position of the fin, each fin (10, 50) also having a folded position in which the fin (10, 50) is intended to come against the hull (2) of the boat (1), and each fin (10, 50) having operating means (31, 32, 33, 34, 35) configured to move the fin (10, 50) between the folded position and the deployed position and vice versa,
each fin (10, 50) comprising a core (11), in particular made of titanium, and a working portion (100) fixed to the core (11) by means of fixing means, and the core (11) being fixed integrally to the maneuvering means.
Fin system according to Claim 1, in which each fin (10, 50) has a front edge, in other words oriented towards the bow of the boat (1), curved backwards, for example so as to give the fin (10, 50) a shape of a shark's or dolphin's pectoral fin,
A fin system according to claim 1 or 2, wherein the securing means is fusible.
Fin system according to one of the preceding claims, in which each fin (10, 50) has a shape adapted to match a predefined shape of the hull (2) of the boat (1), in the folded position, in which the fin ( 10, 50) is pivoted to come against a lateral side (21) of the hull (2) of the boat (1).
Fin system according to one of the preceding claims, in which each fin comprises an anti-heel portion (102) having an airfoil and an anti-drift portion (101), the anti-heel portion (102) being substantially horizontal and the anti-drift portion (101) being substantially vertical in the deployed position of the fin.
Fin system according to one of the preceding claims, in which, for each fin, the maneuvering means comprise pivoting means comprising at least one pivot, adapted to pivot the fin (10, 50) around a pivot axis (X), between the folded position and the deployed position and vice versa.
Fin system according to the preceding claim, in which the pivoting means are configured to be fixed to a lower part of the hull (2), between the keel (5) and the side chine of the boat (1).
Fin system according to Claim 6 or 7, in which, for each fin, the maneuvering means comprise means for displacing (33) the pivot axis (X) of the fin (10, 50), configured to modify fin incidence (10, 50).
Fin system according to one of the preceding claims combined with claim 5, comprising control means configured to maintain the anti-heel portions (102) of the fins (10, 50) horizontal.
Fin system according to one of the preceding claims, in which, for each fin, the fixing means are fusible and are configured to allow separation of the working portion (100) from the core (11 ), automatically or under command.
Fin system according to one of the preceding claims, in which each fin (10, 50) comprises a cable (13) connecting the working portion (100) to the core (11) and configured so that, when the portion work (100) is separated from the core (11), the cable (13) tows the working portion (100) on the side and / or at the rear of the boat (1) in navigation.
Fin system according to one of the preceding claims, in which each fin (10, 50) comprises locking means (35) for locking an angular position of the fin (10, 50) between a plurality of positions of which at least the stowed position and deployed position.
Boat (1), in particular an offshore sailboat, comprising a hull (2) having a flat rear portion, and a system of fins according to one of the preceding claims, the system of fins being fixed to the hull (2) of the boat (1 ).
Boat (1) according to claim 13, comprising means for producing electrical energy connected to the articulation and pivoting device, and configured to produce electrical energy when the boat (1) is at anchor.
Boat (1) according to one of claims 13 to 14, the fin system (10, 50) comprising a pair of front fins (10) and a pair of rear fins (50), in which the front fins (10) have a bearing effect and the rear fins (50) are configured in such a way that when the port front fin (10) is in the extended position and the starboard front fin (10) is in the folded position, the wind is coming from the starboard side, then the starboard rear fin (50) is in the deployed position and its incidence is adjusted so as to be plunging, the port rear fin (50) being in the folded position or in the deployed position with a bearing incidence, and, conversely, when the front fin (10) starboard is in the deployed position and the forward fin (10) on the port side is in the folded position, the wind is coming from the port side, then the rear fin (50) on the port side is in the deployed position and its incidence is adjusted so as to be plunging, the starboard rear fin (50) being in the folded position or in the deployed position with bearing incidence.
Boat (1) according to one of Claims 13 to 15, the boat (1) having a waterline length, in which the respective incidence of the fins (10, 50) is configured to lift the bow of the boat (1) , in particular 1% to 3% of the waterline length of the boat (1).
Boat (1) according to one of Claims 13 to 16, the fin system (10, 50) comprising a pair of front fins (10), in which the pivot axis (X) of the front fins (10) is pinched forward, that is to say that the pivot axes of the front fins (10) on either side of the longitudinal axis (D) of the boat (1) are concurrent forwards.
Boat (1) according to one of Claims 13 to 17, in which the fins are connected to the keel and are configured to rest on the bottom when the boat (1) is grounded.
Boat (1) according to one of claims 13 to 18, in which the fins (10, 50) are configured to be deployed at anchor, the system comprising at least one nitrogen ball connected to the articulation and pivoting device and configured to damp the pivoting movements of the fins (10, 50) due to the surf.
Boat (1) according to one of claims 13 to 19, the fin system (10, 50) comprising a pair of front fins (10), in which the front fins (10) generate a center of thrust participating in a lift bow of the boat (1) located forward of a center of flotation of the boat (1), on each side of the longitudinal axis (D) of the boat (1), in particular located from 5% to 20%, by example from 8% to 10%, of the waterline length of the boat (1), forward in relation to the center of flotation of the boat (1).