Patent Application
20070157864
The technical scope of the present invention is that of boats, and more particularly boats comprising drag reduction and/or stabilising devices.
In the nautical domain, hydrodynamic drag is sought to be reduced so as to make boats quicker thereby reducing their fuel consumption.
This reduction in drag may be obtained by reducing the support surface on the water. To reduce this surface, vessels with submerged float are known or boats which use the principle of foils, such boats namely being known as hydrofoils.
Thus, U.S. Pat. No. 4,993,348 describes a boat comprising a submerged float. Its submerged stabilising device however suffers the drawback of having its range limited by hydrodynamic drag, thereby reducing its effectiveness.
U.S. Pat. No. 6,578,507 describes a boat comprising arms fitted at their ends with foils enabling the boat, when navigating at high speed, to be borne only by its foils. Such a device suffers the drawback, however, of having no stability regarding pitch and roll and does not enable the trim to be kept stable when navigating into waves.
The purpose of the invention is to overcome the drawbacks of currently known devices by proposing a boat that simultaneously offers low hydrodynamic drag and stabilisation of the boat with respect to the waves when navigating at high speed. This stabilisation concerns all the five parasitic components of roll, pitch, yaw, as well as the alternative movements of the centre of gravity of the boat due to the passage of waves, constituted by the vertical movement of the centre of gravity (alternatively up and down) and the lateral movement of the centre of gravity (alternatively offsetting from port to starboard). The invention also aims to regulate the torque to which the sails are subjected when the boat is wind propelled.
The invention thus relates to a hydrodynamic stabiliser for a boat, comprising a submersible strut in the water supporting at its end a first substantially horizontal submerged aileron, mounted able to rotate with respect to the submersible strut according to a horizontal pivot, wherein the first aileron comprises a trailing edge flap jointed to rotate around an axis near to the trailing edge of said aileron and wherein said flap is controlled by a rotational drive mechanism with respect to said aileron so as to orient said aileron.
According to one characteristic of the invention, the stabiliser comprises a second substantially vertical submerged aileron that rotates around the submersible strut and which comprises motor means so as to be oriented.
According to another characteristic of the invention, the stabiliser comprises a second substantially vertical aileron able to rotate freely around the submersible strut and comprising a trailing edge flap jointed to rotate around an axis near to the trailing edge of said second aileron, said flap being controlled by a rotational drive mechanism with respect to the second aileron so as to orient said second aileron.
According to yet another characteristic of the invention, the submersible strut comprises a streamlined fairing able to rotate freely around said submersible strut so as to freely orient itself in the local flow direction of the water.
According to another characteristic of the invention, return means, of the elastic or motor type, are positioned between the submersible strut and the rotating streamlined fairing so as to impose a restoring torque on said fairing when this fairing is angularly offset.
According to another characteristic of the invention, the rotating streamlined fairing comprises a hydrodynamic lift element on its downstream side that is fixed with respect to said fairing or is able to be oriented in vertical rotation with respect to the fairing.
The invention also relates to a stabilisation device for a boat implementing at least one stabiliser, wherein said at least one stabiliser is carried by a substantially horizontal arm integral with the boat, said arm being located above the water.
According to yet another characteristic of the invention, certain arms are made-integral with the boat by a pivot type link with several lockable positions so as to make them foldable.
According to another characteristic of the invention, certain arms are constituted by several sections connected together by a pivot type link with several lockable positions so as to make them foldable.
According to another characteristic of the invention, certain submersible struts are integral with an arm by means of a pivot link with a substantially horizontal axis able to be locked in several positions, a lowered position for said submersible struts when the orientable hydrodynamic ailerons are in use and a raised position for said submersible strut-s when said ailerons are not in use, the boat being immobile or moving at low speed.
According to another characteristic of the invention, the retention of certain submersible struts in the lowered position is ensured by resistance locking calibrated for a force tending to push back said submersible struts, wherein said locking leaves said submersible struts able to rotate backwards and upwards when said limit resistance has been attained.
According to another characteristic of the invention, the stabilisation device comprises a calculator cooperating with static and/or dynamic sensors and piloting the orientation means of the aileron or ailerons so as to vary their orientation according to the movements of said boat.
The invention also relates to a load compensation device to orient the sails of a boat or sailing craft, wherein it firstly comprises, a global elastic device pressing on a fixed part of the boat and comprising an output part able to move on a certain course, or a certain displacement, said mobile output part transmitting an elastic load whose intensity increases according to the amplitude of its displacement, said global elastic device being constituted by one or several elastic organs positioned between said fixed part of the boat and said mobile output part, the addition of the individual elastic loads of said elastic organs supplying the global elastic load to said mobile output part of said global elastic device, and secondly, a device to transmit the movement of said mobile output part of said global elastic device to said sails, said movement transmission device changing its transmission ratio according to the angle of orientation of said sails such that the elastic restoring torque which it exerts on said sails, tending to bring the mean plane of the latter parallel to the plane of symmetry of the boat, or sail craft, is of constant intensity, or else of slightly and gradually increasing intensity, when said sails pivot from the orientation corresponding to the “close-hauled” point of sailing to that corresponding to the “following wind” point of sailing.
According to another characteristic of the invention, the sail orientation organ is a sheet connected at one end to the sails and winding at the other around a drum integral with or linked in rotation to a drum winch with variable winding radius acting as the movement transmission device.
According to another characteristic of the invention, the global elastic device comprises means to adjust the mean elastic load enabling it to be adapted to the prediction, for a given lapse of time, of the mean orientation load of the sails.
According to another characteristic of the invention, the compensation device comprises means to adjust the sail orientation angle, and said orientation angle adjustment means comprise a manual handling organ.
According to another characteristic of the invention, the compensation device comprises means to adjust the orientation of the sails and said means comprise an actuator controlled by a signal from a calculator or from control means piloted by a member of the crew.
According to another characteristic of the invention, the compensation device comprises bidirectional limitation means for the load, force or torque, communicated by the actuator to the sails.
According to another characteristic of the invention, the global elastic device comprises one or several pneumatic or hydraulic jacks linked by one or more lines to one or more tanks containing compressed gas.
According to another characteristic of the invention, at least one tank is connected by means of a valve to a source of pressure, depression or free air, so as to be able to modify the pressure present in said tank.
According to another characteristic of the invention, certain elastic organs of the global elastic device may be suspended from use when navigating, either by the temporary uncoupling of their own elastic movement output organ with respect to the device to transmit movement to the sails, or by the temporary uncoupling of their base with respect to the boat structure to which said base is usually joined, or by the temporary neutralisation of their elastic properties, then brought back into use when navigating by re-coupling the elastic organs temporarily uncoupled or by re-establishing the elastic properties having been temporarily neutralised.
According to another characteristic of the invention, the movement transmission device comprises at least two drums revolving freely around shafts fixed with respect to the boat structure, coupled in rotation, either directly, or by means of a constant or variable ratio transmission mechanism, drums onto which two opposite winding cables are anchored one of which at least is wound in a groove of variable winding radius, the first cable being linked directly or by means of tackle to the elastic movement output organ of the global elastic device, the second cable being linked directly or by means of tackle to a point of the sails enabling them to be oriented.
According to another characteristic of the invention, the actuator of the compensation device is constituted by, or comprises, a rotating electric stepper motor.
According to another characteristic of the invention, the compensation device comprises a load, force or torque amplifier, comprising at least one streamlined submerged blade with hydrodynamic lift, which may be oriented around a pivot parallel to its longitudinal axis, this pivot being mobile transversally to the current due to the displacement of the boat.
According to another characteristic of the invention, the actuator of the compensation device is controlled by a calculator linked to sensors enabling the orientation of the wind direction and the sails to be measured with respect to the boat.
According to another characteristic of the invention, substantially vertical stanchions integral with the boat, surrounded by freely-turning cylindrical sleeves, are provided to intercept the passage of the sheet or sheets when they reach the fore part of the boat so as to reduce stressing on the global elastic device.
The invention also relates to a boat comprising a platform, at least one main, completely submerged, streamlined float, integral with the platform by one or more supporting pylons which take up the full weight of the platform to keep it out of the water, wherein it comprises arms radiating out from the platform, which are substantially horizontal and which support submersible struts extending into the water, fitted with submerged orientable ailerons with hydrodynamic lift effect, said arms being located above the water, mobile streamlined fairings, freely rotating under the effect of the local current and individually enveloping each supporting pylon, at least three auxiliary closed-hull floats, watertight and streamlined, spaced around the platform to ensure balanced trim when immobile or at low speed, integral with the radiating arms or with the platform.
According to another characteristic of the invention, the boat comprises a stabilisation device, provided by said radiating arms, said submersible struts, and said orientable ailerons.
According to another characteristic of the invention, the boat comprises an adjustable preload device enabling the boat's mass to be increased or decreased by means of ballasts with adjustable water intake.
According to another characteristic of the invention, the submersible struts extending into the water as well as certain auxiliary floats are positioned near to the ends of radiating arms.
According to another characteristic of the invention, at least one auxiliary float is fixed to a radiating arm by a link having several lockable positions thereby enabling this float to be brought closer to the platform when the craft is stopped or by a pivot type link with a substantially vertical hinge pin having several lockable positions.
According to another characteristic of the invention, the boat comprises means to measure the position, inclination, speed and/or acceleration, cooperating with a calculator so as to determine the movements of the boat and to model these movements as roll, pitch, yaw movements and/or alternating movements of the boat's centre of gravity due to the passage of the waves, constituted by the vertical movement of the centre of gravity (alternatively up and down) and the lateral movement of the centre of gravity (alternatively offsetting from port to starboard).
According to another characteristic of the invention, the boat comprises measurement means, such as anemovanes, sail orientation sensors, submerged vanes, pressure sensors, surface reflection sonars, surface probes, video cameras, or any other means cooperating with the calculator so as to determine the wave movement upstream of each main submerged float, to model the movements of the water transversal to the path of the boat along the axis of each of said floats, these movements being broken down, for example, along two non parallel transversal axes, or to determine the aerodynamic forces on those boat elements offering wind resistance.
According to another characteristic of the invention, the calculator cooperates with the orientation means for the orientable ailerons so as to orient them according to the simulation of the boat's movements and/or the wave movements and/or the aerodynamic forces, to thereby provide stabilisation for the boat by controlling its trim and trajectory.
According to another characteristic of the invention, certain orientable ailerons comprise an angular sensor which measures the angle of rotation of the ailerons with respect to the submersible strut and cooperates with the calculator.
According to another characteristic of the invention, the boat comprises a balancing device with mobile masses permanently-adjustable by the lateral and/or longitudinal displacements of mobile counterweights along guides, positioned along such guides by mechanisms comprising actuators, or comprising a mass of water that can be transferred between distanced tanks, said balancing device cooperating with the calculator so as to modify the position of the boat's centre of gravity according to its movements and to the unbalancing effects due, for example, to the distribution of the payload or to the wind.
According to another characteristic of the invention, the balancing device comprises tanks located in the auxiliary floats and partly filled with water, said tanks being connected together by piping and at least one pump cooperating with the calculator so as to distribute the water among the tanks.
According to another characteristic of the invention, each supporting pylon located between a fully submerged main streamlined float and the platform is retractable, with several lockable positions, as well as the rotating fairing surrounding it, in a housing in said platform.
According to another characteristic of the invention, the boat comprises wind propulsion means and the orientation of at least one wind propulsion means is ensured by a load compensation device to orient sails.
A first advantage of the boat according to the invention lies in the fact that as from a certain speed and in waves of a depth less than the height of its rotating fairings it is not affected by the effects of roll, pitch, yaw, transversal sway (either upward/downwards or port/starboard). This advantage comes from the combination of the fully submerged main streamlined float(s) (with constant Archimedes' thrust), from the characteristics of the elements breaking the surface (small section and incidence on the Archimedes' thrust, streamlining and rotating vane minimise the effects of transversal waves), from the long radiating arms (wide lever arm contributing to the lift of the submerged orientable ailerons) and the orientation of the ailerons which oscillate with the waves (incidence and lift remaining proportional to the stabilisation load setting given, despite the wave passage).
Another advantage lies in the fact that the hydrodynamic drag is extremely reduced, thereby enabling the boat to reach high speeds.
Another advantage lies in the facility of access to shallow waters thanks to the reduced draught enabled by lifting the submerged main streamlined float(s) and by lifting the submersible struts, as well as in the facility of berthing in harbours thanks to the reduced horizontal encumbrance enabled by the foldable radiating arms.
Other characteristics, particulars and advantages of the invention will become more apparent from the following description given hereafter by way of illustration and in reference to the drawings, in which:
a to 4d show embodiments of rotating fairings according to the invention,
a and 11b shows the functioning of an embodiment of the adjustable preload device,
a shows an example of a sailing boat equipped with several load regulation devices according to the invention,
b is a functional schematic drawing of a device according to the invention,
The stabiliser functions as follows:
During the displacement of the boat, the aileron 1 spontaneously orients itself under the effect of the opposing torques due to its own hydrodynamic lift force and to the hydrodynamic lift force of its flap 7.
The flap 7 is substantially of the same span as its aileron 1, but has a lesser chord, for example three to four times shorter. The deflection of the flap is ensured by a servo-mechanism of angular orientation (not shown) of the flap 7 with respect to its aileron 1. The deflection angle of the trailing edge flap 7 with respect to the orientable aileron 1 is determined by an onboard electronic calculator (of a known type) which pilots the orientation servo-mechanism. This angle between the aileron 1 and its flap 7 generates a hydrodynamic lift force of the trailing edge flap which forces the orientable aileron 1 to orient itself by taking up an incidence with respect to the current, which in turn generates a hydrodynamic lift force of the aileron. The latter is in a near, but opposite direction and is considerably stronger than the lift force of the flap 7 because of the ratio of lift surfaces of the aileron 1 and the flap 7.
When the boat is confronted with high transversal waves and the fairing 6 is uncovered in the troughs of the waves, the hydrodynamic vane effect of the fairing 6 is no longer fully effective. The inertial effect to which the fairing is subjected drives it in rotation in its momentum resulting in uncontrolled rotational oscillations. And when the following wave covers up the fairing 6 once again, the fairing may well be in a position transversal to the local displacement of the water. This would result in a parasitic transversal lift, the maintenance of forced oscillations of the fairing, and above all an increase in the hydrodynamic drag which would hamper the boat's speed and/or increase its fuel consumption. So as to avoid such effects, return means 9, of the elastic or motor means type, may be provided between the submersible strut 5 and the rotating streamlined fairing 6 so as to impose an angular restoring force on the fairing when this is angularly offset with respect to the axis of symmetry of the boat. Such return-means are widely known. By way of example, a torsion spring or progressive torque servo motor may be mentioned. The aforementioned motor may also be piloted according to the measurement of the angle between the water flow and the fairing 6 so as to align the fairing with the current. Means for such measurement are already widely known. By way of example, a set of submerged pressure sensors arranged on the fairing and cooperating with a calculator or else an angular sensor of a known type measuring the orientation of a submerged vane revolving around a vertical hinge pin integral with the fairing may be cited.
The hydrodynamic stabiliser according to the invention may also be made without trailing edge flaps 7 and 8 but wherein the orientation of the aileron or ailerons 1 and 2 is carried out by motor means (for example an electric motor positioned between the aileron and its hinge pin). Such an arrangement, however, does not enable piloting of the ailerons to be performed as reliably, simply and efficiently as in the embodiment previously described which has flaps.
Indeed, in a first simple variant having no trailing edge flaps, the calculator sends an orientation angle by way of a setting to the orientation means of ailerons 1 and 2, with respect to their mean position, proportional to the lift force required to stabilize the boat; the drawback to this method being that the angle of incidence of the aileron with respect to the current fluctuates according to the transversal speed of the water due to the waves, and thus that the actual hydrodynamic lift force of the aileron also fluctuates around the setting value, hence less efficient stabilisation than previously. In a second variant also without trailing edge flaps, the calculator sends an orientation angle by way of a setting to the orientation means of ailerons 1 and 2, with respect to their mean position, proportional to the angle of orientation required for the angle of incidence of the aileron with respect to the current remains proportional to the lift force required to stabilize the boat (to obtain a constant force, a signal must be sent that fluctuates according to the waves). This second variant without flaps suffers the drawback of requiring means to measure the water's local flow direction to be connected to the calculator. As explained above, such measurement means of the relative orientation angle of a flow with respect to a solid in movement in a fluid are already widely known (for example based on an angular sensor connected to a submerged hydraulic vane with an axis perpendicular to the axis of the boat or based on submerged distributed pressure sensors).
The orientable ailerons 1, 2 may be fitted with means to improve their lift by suction by means of a pump of the boundary layer through small diameter openings scattered across their surface, these openings being periodically cleared by being briefly flushed out in the opposite direction by means of another pump or by compressed air. According to a variant embodiment, the suction is limited to the suction face of the ailerons and the suction face is switched on when the orientation motor torque direction of the aileron is inverted or when the deflection direction of its trailing edge flap is inverted.
a to 4d show embodiment of the rotating fairings 6 according to the invention. With the aim of overcoming the drawbacks linked to the erratic orientation of the rotating fairing in case of high waves, the latter may be equipped with a hydrodynamic lift element 18 acting in addition to or in replacement of the above-mentioned return means 9.
a shows a rotating fairing 6 that comprises a hydrodynamic lift element 18 made in the form of a rigid plane plate, integral with the rotating fairing's trailing edge 6 and positioned in a vertical plane of symmetry of said fairing.
b shows a rotating fairing 6 comprising a hydrodynamic lift element 18 made by an arm 19 integral with the trailing edge of the rotating fairing 6 and which rigidly carries at its downstream end a rigid plane plate 20, arranged in the vertical plane of symmetry of said fairing.
c shows a rotating fairing 6 comprising a hydrodynamic lift element 18 made by two arms 19 and 19′ integral with the trailing edge of the rotating fairing 6 and which carry a streamlined wing 28 rigidly integral or hinged around a vertical axis. In the hinged version, the wing 28 will be oriented with respect to the fairing 6 by means of a servomechanism piloted according to the angle measured between the water flow and the fairing 6, so as to cancel this angle. Means to measure this angle have been described previously with reference to
d shows a rotating fairing 6 comprising a hydrodynamic lift element 18 made by an arm 19 integral with the trailing edge of the rotating fairing 6 and which rigidly carries at its downstream end a streamlined wing 23.
These embodiments are given by way of illustration and are in no way restrictive. Other embodiments of hydrodynamic lift element 18 may be envisaged, for example by providing the trailing edge of the streamlined wing 28 with a flap that can be oriented by motor means positioned between said flap and this wing 28.
FIGS. 5 to 7 show examples of the application of the hydrodynamic stabiliser according to the invention to different types of boats.
The boat's stabilisation device operates as follows:
The electronic calculator 43, to which the motor means for the aforementioned hydrodynamic stabilisers 15 and sensors 25 are linked, forms part, either alone or with one or several other electronic calculators with which it is interconnected, of a navigation system on board the ship.
This system comprises sensors which are all of known types, integral with the structure of the ship, a rotating fairing, or else a hydrodynamic stabiliser, and connected to one or two abovementioned calculators and this system comprises software equipped with a measurement acquisition function from these sensors, such that said sensors and the aforementioned software function cooperate so as to establish numerical values which are periodically updated—for example, 10 to 20 times per second—for the deviation in rotation components of the ship with respect to its nominal trim or heading, which are required to establish the control orders for the orientation actuators of the aforementioned submerged ailerons to the hydrodynamic lift force depending on the movements of the boat and so as to obtain the desired stabilisation effects.
The desired effects, depending on the different embodiments of the device according to the invention, are one or several angular stabilizations (in roll, pitch, yaw or one or several components of these movements).
The calculator 43 determines the necessary stabilising torque for each of the desired angular stabilizations, and then it deduces the required hydrodynamic lift force of each orientable aileron—taking into account its layout with respect to the boat—, and lastly it sends the setting to the orientable aileron's motor means with the aim of obtaining this lift force. It is preferable for this setting to be the deflection angle of the trailing edge flaps 7 and 8 (FIGS. 1 to 3) with respect to their orientable ailerons 1 and 2 (taking the speed of the boat into account), said orientable ailerons thereby spontaneously taking up the appropriate incidence at the desired lift force whilst accompanying the wave movement, without the calculator having to take said wave movement into account.
In another example, not shown, a cruise liner will be provided with six stabilisers 15 according to the invention with a single aileron 1 (as shown in
Such an arrangement advantageously enables the submersible strut 5 to be held in its low position by a resistance locking calibrated for a force tending to push back the submersible strut. This embodiment leaves the submersible strut 5 free to rotate rearwards and thus to be raised when the ultimate stress has been reached.
The hydrodynamic stabiliser according to the invention can also be made without the trailing edge flaps 7 and 8 (FIGS. 1 to 3) whilst ensuring the orientation of the aileron or ailerons 1 and 2 by motor means (for example, an electric motor positioned between the aileron and its axis of rotation). But such an embodiment does not enable piloting of the ailerons that is at the same time as reliable, simple and efficient as the embodiment described with reference to FIGS. 1 to 3.
The preferred embodiment is the one in which the orientable ailerons 1 and 2 are provided with trailing edge flaps, respectively 7 and 8, which procures the double advantage of needing lower power consumption for the orientation and of ensuring better reliability (it is unnecessary for the setting signal to be corrected to avoid a fluctuation of lift due to the waves, which in turn prevents the current direction sensors from being perturbed by algae).
Additionally and preferentially, ailerons of the “compensated” type provided with trailing edge flaps will be used. By “compensated aileron” we mean an aileron whose axis of rotation is located substantially on the profile chord, at around 20% of the length of this chord downstream of the leading edge.
Each supporting pylon 16 and each submersible strut 5 is encompassed by a mobile hydrodynamic fairing 6 freely rotating under the effect of the local current so as to reduce its hydrodynamic drag as described with reference to FIGS. 1 to 3 and 4a to 4d. The mobile hydrodynamic fairing concept is already known and therefore does not require further description. Reference may be made, however, to patent FR-2817531 which describes such a fairing. It will, however, be preferable to use a rotating fairing whose restoring torque is increased in the event of misalignment, for example thanks to elastic return means (such as a torsion spring or progressive torque servo motor) and/or thanks to a tail piece with hydrodynamic lift effect located beyond the trailing edge of the fairing's hydrodynamic profile and constituted by a vertical plate integral with the fairing or by a streamlined wing able to move around a vertical axis integral with the fairing and oriented by motor means in cooperation with means to measure the fairing angle with the direction of the local flow of the water. Fairings 6 rotating around supporting pylons 16 of the same type as those described with reference to
The boat also comprises an electronic calculator 43, of a known type, cooperating with means to measure the position, inclination, speed and/or acceleration so as to determine the boat's movements and to model these movements as roll, pitch, and yaw movements as well as alternating movements of the boat's centre of gravity due to the passage of the waves and constituted by the vertical movement of the centre of gravity (alternatively up and down) and by the lateral movement of the centre of gravity (alternatively offsets to port and to starboard). These measurement means may be, for example, height sensors, air sonars 34 by reflection off the water surface, accelerometers 26, submerged pressure sensors, submerged vanes, gyroscopes, or any other means to measure the position, movement or acceleration, so as to determine the boat's movements and to model them as movements of displacement that are either roll, pitch or yaw movements, and transversal displacement movements of the boat's centre of gravity along two non parallel transversal axes, for example vertical and horizontal.
The calculator 43 also cooperates with means to measure the boat's environment so as to determine the wave movements upstream of each main submerged float 51 (this embodiment only has one of them but a boat may be envisaged according to the invention which has several of them), to model at the float's axis the movements of the water that are transversal to the path of the boat as horizontal movements and vertical movements, subsequently to model the transversal hydrodynamic forces on the main float 51 due to the waves and also to determine the aerodynamic forces on the elements of the boat offering wind resistance. These different means may be, for example, anemovanes, sail orientation sensors, submerged vanes, submerged pressure sensors, air sonars 34 by reflection off the water surface, water surface probes, or else video cameras. When the boat is navigating at a fast rate, with the platform 52 and auxiliary floats 53 entirely out of the water, the calculator 43 cooperates with the orientation means for the submerged orientable ailerons with hydrodynamic lift and with the mobile mass balancing device (described later) so as to maintain the mean level of the water surface substantially at mid-distance from the parts of the boat that must remain out of the water (platform 52 and auxiliary floats 53) and the parts of the boat that must remain submerged (main float 51 and orientable ailerons 1, 2).
The calculator 43 is lastly linked, if need be, to a manual control organ enabling the crew to select the degree of stabilisation of the boat, adjustable by software between the maximum stabilisation (objective 100% stabilisation with respect to short waves and 0% tracking with respect to long waves) and the maximum contouring (0% stabilisation with respect to short waves and objective 100% tracking of the long waves). However, the software keeps full control to ensure as a priority a balance of trim and altitude for the boat that is enough to limit the probability, when the boat is navigating at speed, with the platform 52 and auxiliary floats 53 fully out of the water, of the platform 52 or an auxiliary float 51 hitting the crest of a wave or of the submerged float 51 or an orientable aileron coming right out of the water in a trough between waves.
The auxiliary floats 53 are spaced around the platform 52 so as to ensure balanced trim when the boat is stopped or moving at low speed. Such an arrangement of the floats illustrates an embodiment of the invention. Other embodiments may, however, be envisaged, for example by making certain auxiliary floats 53 directly integral with the platform 52. In this embodiment, the boat comprises four floats, but the invention may also be built with three floats, or more than three floats.
a and 11b shows the functioning of an adjustable preload device 500 enabling the boat's mass to be increased or decreased. In this embodiment, the platform 52 comprises a tank 17 located near to the boat's centre of gravity and preferably in the lowest part of the boat. This tank 17 is connected to a filling and draining device (for example a pump) enabling it to be more or less filled with water. When the boat is stopped or is navigating at low speed, it is preferable for all the auxiliary floats 53 to be in contact with the water so as to guarantee the boat good stability (
So as to optimally regulate the boat's preloading, submerged static pressure sensors 40 can be positioned on the submersible struts or on the submerged streamlined float 51 or else air sonars by reflection off the water surface, carried by the floats 53. Piping can be installed to fill and drain the tank 17 by a slot arranged in the fairing 6 rotating around a supporting pylon. More generally, slots in the rotating fairings 6 of the supporting pylons or of the hydrodynamic stabilisers may be used to pass organs linking an emerged zone and a submerged zone of the boat (such as for example: cables, piping, revolving shafts).
When navigating at high speeds, if a boat were subjected to an angle of inclination α that is too great with respect to the vertical, one or two auxiliary floats 53 on the port side would begin to sink into the water and additionally the two substantially vertical orientable ailerons 2 on the starboard side would begin to emerge from the water and the substantially horizontal ailerons 1 on the starboard side would begin to cavitate and would be on the point of emerging. This would respectively cause a braking effect to port tending to make the boat rotate towards port, then a risk of sudden and total loss of vertical lift of the starboard horizontal orientable ailerons 1 leading to a sudden increase in the list to port and an increased bearing of the port side auxiliary floats 53, thereby accelerating the rotation to port. Similarly, an excessive inclination of the boat either forwards or backwards would cause comparable drawbacks. It is thus essential for a balancing device to be provided enabling the position of the boat's centre of gravity to be modified, laterally and longitudinally, according to the external loads applied to the boat or to a poor distribution of the payload on board the boat.
The balancing device 501 comprises closed and watertight compartments 54 located in the auxiliary floats 53 and partly filled with water, piping 55 connecting these compartments together and at least one pump 11 and possibly a distributing organ carrying out the distribution of the water between the different compartments. This pump 11 and this distributing organ may be linked to the tank 17 so that tanks 54 are completely filled when the boat is immobile or at slow speeds. The constantly adjustable mobile mass balancing device operates as follows:
The calculator 43 (
In the normal navigation configuration of the boat, the arm 14 is fully deployed and the link between the two sections is locked so that they are not able to rotate with respect to one another. The float 53 is fixed near to the end of the arm 14, near to the submersible strut 5. When the crew wishes to reduce the horizontal encumberment of the boat at slow speeds, for example to facilitate access to the harbour, the arms 14 may be folded. To take up this folded position, the crew unlocks the float 53 then brings it closer to the platform 52 up to the end of section 14a integral with the platform 52 and locks the float 53 in this new position (shown in dotted lines in the Figure). The float 53 being locked in this position, the link 12 between the two sections of the arm 14 is unlocked and the second section 14b is folded over the first section 14a as shown in dots and dashes in the Figure. So as to facilitate this manoeuvre, a cable 47 may be positioned between the end of the arm 14 and a pulley located at the top of the mast 68. A variant embodiment consists in fixing the auxiliary floats 53 to the radiating arms 14 by pivot type links with substantially vertical axis with several lockable positions. This variant embodiment is particularly well adapted when the arms 14 are fixed to the platform 52 by a vertical pivot type link with several lockable positions, such as that described with reference to
The following paragraphs related to the boat according to the invention describe additional embodiments that may be made of said boat.
In this embodiment of the boat according to the invention, the hydrodynamic stabilisers 15 are of the type shown in
The example described above is a sailboat, but the boat according to the invention may also be engine-propelled, for example using onboard fuel. In case of propulsion by submerged propeller(s), it will be advantageous to place the propeller(s) at the rear point of the (or of each) submerged float 51.
To facilitate access into harbours, the main submerged float 51 may be able to be raised up against the platform 52 through the retraction of the supporting pylons 16 with their rotating fairing 6 into housings in said platform, and may even be partly embeddable in said platform thanks to vault accommodation arranged in its lower zone (detail not illustrated).
To increase the boat's speed, the main submerged float 51 may be provided with drag reduction means by suction by means of a pump of the boundary layer through small diameter openings scattered across its surface, these openings being periodically cleared by being briefly flushed out in the opposite direction or by means of another pump or by compressed air.
For a boat of large size, an access from the platform to the compartment of the main submerged float 51 may be provided for maintenance visits or for goods or freight to be stored. This could be a permanent access by a passage via a supporting pylon 16, which is tubular in this case, or a temporary access when the boat is immobile by means of a vertical tube sliding by motor means and made watertight in the platform 52 so that this tube forms a temporary communication well between the platform and the submerged float 51, in this case, the lower end of this tube being provided with peripheral sealing means (for example, a seal or a ring-shaped suction cup linked to a suction pump) fits tightly against the top of the submerged float 51, around a watertight door-arranged in the wall of this float; a pump enabling the water to be evacuated from the tube before the door is opened; when navigating, this tube remains retracted in the platform 52 behind a door.
So as to guarantee good stability for the boat according to the invention when it is of the wind propelled type and so as to optimise the use of the wind as a motor element, it is important to be able to constantly adjust the orientation of the boat's sails. The invention thus also relates to a load compensating device to orient a boat's sail. Such a device can be adapted to and used by any type of sail boat, as well as on other sail craft, for example a sand yacht. The purpose of the load compensation device according to the invention is to exert a variable torque (or a load) on the sail orientation organ, so as to enable either an automatic orientation of said sail according to the wind, or assistance at a defined orientation. By “sail” we mean any organ using the wind force as a motor means applied to the boat, this organ may, for example, be a sail, a wing mast or a Turbosail. By “sail orientation organ”, we means the organ integral with the sail and by which the orientation angle with respect to the boat of said sail may be fixed, that is to say, for example, a sheet fixed to one end of the sail or near to the boom integral with the sail, or a connecting rod whose end is integral with the sail or a crank integral in rotation with said sail (for example integral with the base of a rotating wing mast or with the boom of a sail), or else a toothed wheel meshing with an endless screw or a chain or else a synchronous belt, wheel coaxial to the axis of rotation of the sail and integral in rotation with said sail (for example integral with the base of a rotating wing mast or with the boom of a sail).
In the embodiment of the load compensation devices of the example given hereafter, sheets act as the sail orientation organ and each sail is a sail either with or without a boom.
a shows the load compensation devices 502 in the orientation of the sails of a boat according to the invention applied to a pleasure sailboat. In this embodiment, the boat comprises a rear sail constituted by a main sail 57 provided with a boom oriented by the mainsheet 56 and a front sail constituted by a jib sail 59 oriented by the sheet 58 located to the leeward side. A central mast 68 supports the main sail 57, the boom and the head of the jib sail 59. The deck 61 is provided with three sheet attachment points: one for the main sail, located to the rear and two for the jib sail, one of which is to the port side and the other to the starboard side. At each of these attachment points, the usual winch is replaced by a device 60 according to the invention to adjust the sheet orienting its associated sail.
b schematically shows an embodiment of a load compensation device 502 according to the invention, comprising a global elastic device 201 whose mobile output organ 71—shown here by a spreader 103 or a cable 71—drives the orientation of the sail by means of a movement transmission device 200. Said movement transmission device 200 orients the sail by means of the sheet 56 (or 58) which here acts as the sail orientation organ, such as defined previously. In the remainder of the description, “sheet traction device” 60 refers to all the elements constituting the device 502, with the exception of said sheet 56 (or 58).
This sheet traction device 60, in the embodiment envisaged in this example, comprises two joined winches 66 and 69 with opposing winding directions, the second of which 69 comprises a groove 70 having a variable winding radius and by a cable 71 pulling a global elastic device 201, schematised by a spreader 103 attached to tensile springs 37 anchored to the structure 30 of the boat. This global elastic device 201 is shown by way of example. However, a global elastic device 201 is preferred which comprises one or several elastic organs, each made by a jack connected by piping to a gas tank as will be described later with reference to
In the embodiment envisaged (
During the design of the device 60, the elasticity properties of the global elastic device 201 and the transmission ratio evolution law of device 200 linked to the evolution of the winding radius on the drum 69 according to the winding angle are selected so as to enable, for a given setting of said properties of elasticity, the moment of the restoring force exerted by the sheet on the sail to be constant, or gradually and slightly rising, when the sail rotates from the orientation corresponding to the “close-hauled” point of sailing to the “following wind” point of sailing. Thus, the tensioning devices 60 for the sheets guarantee that the capsizing torque due to the sails in the event of sudden gusts is not able to increase dangerously (the sail tending to spontaneously orient itself in the axis of the wind). In
In the embodiment envisaged by this example, each of the sheet tensioning devices 60 comprise a cylindrical drum 66, shown more fully in
The evolution of the ratio of the winding radii of the sheet 56 or 58 on drum 66 and of the antagonistic cable 71 on drum 69 according to the angle of rotation of said drums is provided such that the moment of the traction force on the sheet with respect to the axis of rotation of the sail increases substantially linearly according to the angle to the mean plane of this sail with the plane of symmetry of the boat, with a total variation of approximately 10% when this angle moves from 0° (boat “head to the wind”) to 180° (boat “rear wind”, sail completely to the front). The invention can also be made differently, for example by also giving drum 66 a variable winding radius, or else by separating drums 66 and 69 and linking them by a gear train, or even by cascading several devices 66, 69 with antagonistic winding.
The invention can be made using one or several elastic organs. In the embodiment envisaged for this example, each elastic organ of the global elastic device 201 is made by a pneumatic jack 72 with quasi-zero friction (
To reach the core of the sheet tensioning device 60 mechanism located under the deck 61, the sheet 56 or 58 passes through the deck (
A second winding guidance mechanism analogous to the previous one is provided (but not shown) for cable 71, arranged symmetrically to the first with respect to the plane perpendicular to the plane of the drawing and passing through the axes of drums 66 and 69.
In
The setting of the unwound length of the sheet at a precise value is piloted by the software of the electronic calculator common to the sheet tensioning devices 60. To this end, firstly the angle of rotation of drum 66 is measured by an angular measurement sensor of a known type, and secondly, a stepper motor of a common type with known pull-out torque has its output shaft integral with the drum by means of a reversible geared rotation transmission mechanism. The angular sensor and the motor's electronic control device are linked to the aforementioned electronic calculator. This sheet regulating device enables the friction to be compensated, whilst allowing the sheet to run in case of abnormal load due to a gusting wind, without losing track of the drum angle, such that an optimal setting may thus be automatically re-established afterwards. The slight angular locking due to the remanent torque of the stepper motor makes constant replenishment of power unnecessary; this slight locking may, if required, be reinforced by a rotary plate ring indexed by spring ball-fitted pawls (every 10°, for example), locked onto the drive shaft.
In the embodiment described previously of the global elastic device, the regulation of the mean elastic load is carried out by modifying the mean pressure in the tank by means of valves. In place of or in addition to this (recommended), it is possible to regulate the mean elastic load by providing several elastic organs and by varying the number of elastic organs in commission at a given time. One means to put an elastic organ out of commission is the temporary elimination of the elastic effect (for example, for jacks, by bringing their chambers to atmospheric pressure using valves). Another means consists in temporarily uncoupling the base or frame of the elastic organ with respect to the boat structure (which can be performed by a removable link of the mechanical or hydraulic type with a coupling jack). Yet another means consists in temporarily uncoupling the mobile output organ of the elastic organ with respect to the movement transmission device 200 (
With reference to
The device according to the invention may be used on any type of sailboat or sail craft (for example, sand yacht). It may also be installed on any type of existing sailboat with enough space below deck to hold the different organs of the device, if necessary by slightly adapting the interior accommodation. Moreover, it is particularly well adapted to boats with stabilisation devices such as described previously.
With respect to known means of wind element orientation, the device according to the invention procures the following advantages: it provides improved comfort for the passengers (list being reduced). It improves safety (reduced risk of capsizing) and no longer requires the constant surveillance of the orientation in competitions. Muscular effort is much reduced in the assistance mode and the consumption of energy is lower than if the device comprised an actuator. The fine tuning of the wind-originating capsizing torque in the automatic mode is particularly advantageous for unstable sailboats, such as those carried by foils or submerged floats.
The embodiment of a load compensation device for the orientation of a boat sail implementing a sail sheet has been given by way of illustration. A compensation device according to the invention can also be obtained by other embodiments. Another possible embodiment consists in linking the variable winding radius drum in rotation, directly or by means of gearing, to the mast 68 supporting the sail or to the sail boom. Other embodiments of the elastic element(s) according to the invention are also possible, which, instead of using the elasticity of a gas in a jack, uses the elasticity of a pressurised gas in a pneumatic accumulator containing a hydraulic liquid in the lower part and whose floor comprises the opening of piping opening out into the chamber of a hydraulic jack, or which uses the elastic deformation of the material of a spring, or else the magnetic force of magnetized elements.
The electric motor actuator aforementioned in the regulation of the orientation of the sail can be advantageously replaced by an automatic pilot for sailboats, of a known type, with a submerged pendular blade mounted loose in rotation around its longitudinal axis and with an orientable trailing edge flap. This automatic pilot can be adapted in the following manner: the deflection angle of the trailing edge flap of the pendular blade will be controlled by a servo motor piloted by a calculator and the two output tiller ropes will be wound, tightened and provided with an anti-slip device, onto a drum mounted free to rotate around a fixed axis with respect to the boat. This drum forms a receiving winch for the pendular movement of the blade when it is displaced transversally to the current when the flap is deflected. Said drum drives drums 66 and 70 in rotation by means of a rotation transmission mechanism with multiplying gears, of a known type. Another solution may consist in driving said drum by a rotational movement transmission mechanism of a submerged variable pitch, reversible, screw, whose blades will be oriented by a servomechanism controlled by the aforementioned calculator, rather than by the tiller ropes of the automatic pilot.
The load compensation device according to the invention may also be advantageously applied to a sail having two sheets acting symmetrically by installing in common the global elastic device 201 (
| Number | Date | Country | Kind |
|---|---|---|---|
| 0313714 | Nov 2003 | FR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/FR04/02933 | 11/18/2004 | WO | 5/23/2006 |
