The invention relates to wind-propelled watercrafts in which at least one sheet element is held with at least one stay rope on a body of the watercraft, in particular a hull. The invention can be employed more particularly with sail ships and other watercrafts as well solely or in combination with additional conventional drives.
Heretofore, it is usual for the propulsion of watercrafts and other vehicles as well to take advantage of wind power to use one or a plurality of sails made of textile materials which are stabilized at least on one mast, and also in addition with so-called booms or yards. Such sails will be aligned in accordance with the wind direction or the desired direction of motion, and utilize at least one component of the wind power which as a rule merely provides one portion of the total wind power for generating propulsion.
With this form, however, turning moments are also acting in the longitudinal axis in which the mast(s) is (are) arranged as well which more or less cause an oblique position about the longitudinal axis of a hull and body of the watercraft, respectively. To actively oppose this effect leeboards and cost effective keel constructions, respectively are employed with sail ships and sailing boats, respectively according to the size of the used sail areas. Since limits are set for this, however, the direction of motion and wind direction can be utilized in an optimized manner to each other only to some extent, and the ship can be adequately steered such that frequently crossing is required with unfavourable wind directions which of course results in an extension of the duration of travel toward a particular destination.
With high wind velocities in particular the mast and masts, respectively is (are) providing a weakest point, and in the case that the mast and masts, respectively is (are) breaking sailing boats and sail ships are nearly incapable of manoeuvring and exposed to the rigours of weather and water without any resistance because of the failed propulsion such that a high potential of danger is given to the ship's crew.
For avoiding said dangers with high wind velocities it can be required to reduce at least one portion of the sail area by reefing sail in order to decrease the forces and turning moments acting on the masts of the ship. Thereby, of course the driving speed of such a boat and ship, respectively is reducing.
Therefore, it is an object of the invention to provide wind-propelled watercrafts by means of which the wind forces can be better used for the propulsion, and the turning moments acting about the longitudinal axis on the body of the watercraft and hull, respectively can be decreased.
In accordance with the invention this object is solved with the features of claim 1. Advantageous embodiments and improvements of the invention can be implemented with the features mentioned in the subordinate claims.
The watercraft according to the invention uses at least a sheet element which is formed similar to a conventional sail or a sufficiently well-known kite as well to increase the propulsion due to the action of wind force, and to largely reduce the tilting moments already mentioned. Such a sheet element which should have a small mass, if possible, is held with at least one stay rope in close proximity to the body of the watercraft wherein the stay rope is attached to the sheet element on at least three points spaced apart from each other to allow the sheet element to be deflected and aligned in the vertical and horizontal directions in order to enable an optimum alignment of the sheet element according to the desired direction of motion under consideration of the respective wind direction.
This can be taking things so far that by means of a stay rope, control the sheet element will be aligned and brought into the wind such that it is allowed to be moved in the vertical direction upwardly and downwardly, respectively within wind layers having higher wind velocities.
Such an element and a plurality of elements as well, wherein a plurality of sheet elements are preferably connected to each other, can be made of a lightweight sheet material. Favourably, flexible materials may also be employed for such sheet elements which deform themselves due to the wind force then, and equivalently increase the drag factor (EW) such that the component of force usable for the propulsion is also increased.
Compressed gas containing chambers can be arranged, formed and also secured, respectively on the one sheet element and a plurality of sheet elements, respectively for increasing the stability as well and lift, as the case may be, for such a sheet element. Such a compressed gas containing chamber which is formed and arranged, respectively in close proximity to the sheet element, and in which compressed gas is contained results in an increase of the stability of such a sheet element. Such compressed gas containing chambers can also achieve a supporting function similar to rigid frame constructions with a smaller mass for sheet elements. By means of one or a plurality of compressed gas containing chamber the form and shape of the sheet element can be defined.
On the compressed gas containing chambers fittings with valves can be provided which allow charging and discharging the compressed gas containing chambers, respectively.
It is more especially advantageous to charge the compressed gas containing chambers with gas having a lower density than air such that a lifting force component can be obtained for the sheet elements. Appropriate charging gases for example are helium, but hydrogen as well. With a sufficiently great volume and sufficient charging with such a gas having a relatively lower density it can be achieved that the lifting force is at least greater than or equal to the weight of the sheet element. However, it should also be greater than or equal to the proportional weight of the stay rope(s), if possible. In this case, the sheet element is freely floating in the atmospheric air, and it is allowed to be significantly easier manoeuvred and aligned relative to the prevailing wind direction. In addition, thus it is prevented from dropping on the ground and water surface, respectively and then an expense action is required to bring the sheet element into the wind again.
However, similar to a conventional captive balloon, the compressed gas containing chamber(s) can also be charged with a gas of lower density, and such a sheet element is allowed to be suspended thereon. In case that a two-dimensional element made of a flexible material has been used it is favourable to use at least two of such compressed gas containing chambers in the form of a captive balloon.
However, the compressed gas containing chambers can also be provided with apertures by means of which they can be charged with air due to a dynamic pressure when the sheet element is directed into the wind.
For enabling the first already mentioned alignment of such sheet elements both in the vertical direction and horizontal direction it is favourable to vary the length of the stay ropes each used between the sheet element and body of the watercraft and hull, respectively. On that occasion, each stay rope can be lengthened and also shortened, respectively one by one individually. It is also possible, however, for such two stay ropes each which are arranged on the sheet element in horizontal and vertical planes, respectively, to be lengthened and shortened, respectively with the same length in the opposite direction.
By simultaneously uniform lengthening or shortening all stay ropes the sheet element can be brought into the wind or can be hauled in.
The elements used to vary the length of the stay ropes are allowed to be pulleys, for example, which the respective stay rope can be wound up on and unwound therefrom, respectively. Such pulleys can be constructed such as the elements which in the sailor's language are designated as “winches”.
The propulsion can be manually carried out in a controlled manner by means of electric motors and backgeared motors, respectively in which the control of the sheet element, thus shortening and also lengthening the stay ropes can occur under consideration of the measured wind direction, the desired direction of motion and/or else as the case may be under consideration of the tensile forces measured on the individual stay ropes by means of an electronic control.
In particular, for each avoiding and reducing the turning moments (tilting moments) acting about the longitudinal axis it is advantageous to vary the point of application of force of the stay ropes on the body of the watercraft and hull, respectively under consideration of the respective wind direction and direction of motion. This applies independently to whether with respect to a plurality of stay ropes these are secured to the body of the watercraft in close proximity to each other or whether a common virtual point of application of force results from the force vectors of these stay ropes.
With this, various solutions are possible.
Thus, on the one hand it is possible to adequately adapt the point of application of force of the stay ropes on the body of the watercraft by means of a guide. In the most simple case such a guide can be a hoop being orthogonally aligned with the longitudinal axis of the body of the watercraft which the stay rope(s) is (are) lead about such that according to the alignment of the sheet element with respect to the longitudinal axis of the point of application of force will be automatically displaced. It is more especially advantageous for this transversal hoop to be curvedly formed such that the convex contour of such a hoop is facing upwardly and in the direction of the front of the body of the watercraft (direction of hoop) respectively and obliquely forwardly.
Such a solution can be additionally improved when such a transversal guide is received within two guides aligned in parallel with the longitudinal axis of the body of the watercraft, and is allowed to be displaced by means of such guides along the longitudinal axis of the body of the watercraft.
Another alternative to vary the point of application of force of the stay ropes is to provide it excentrically on a rotary table which is rotatable with its centre about a vertically aligned rotational axis such that the point of application of force with respect to the longitudinal axis of the body of the watercraft is allowed to be automatically varied in its position due to the excentric arrangement and the turning moments correspondingly acting. However, such a variation of position can also be implemented in a controlled manner with an equivalent rotary drive for the rotary table.
A third alternative of varying the point of application of force for the stay rope(s) is in the use of a lever shaped jib boom which on one side comprises a link by means of which the lever shaped jib boom is attached, e.g., to the longitudinal axis of the body of the watercraft. Then, the stay rope(s) are secured in a distance preferred at the end of this jib boom such that during pivoting the jib boom about the link it can be achieved a variation of the position of the force application point of the stay rope(s) with respect to the longitudinal axis of the body of the watercraft. Ball and socket joints and universal joints, for example, are suitable as a link which can also be secured inside a guide which is aligned at right angles to the longitudinal axis.
The point of application of force can also be varied with respect to the so-called lateral centre of pressure, and selectively adjusted such as still to be described in the following. With the lateral centre of pressure it deals with the area related centre of inertia of the projected area on the longitudinal axis of the watercraft. It is allowed to coincide with the mean transversal axis, and the transversal axis can be located close to the lateral centre of pressure, respectively such that this as well can be used as reference for the point of application of force in a simplified manner.
By means of selectively influencing the position of the point of application of force with respect to the lateral centre of pressure it is also allowed for the direction of motion (course) of the watercraft to be influenced. Thus, with a position of the point of application of force in front of the lateral centre of pressure the watercraft can be turned into the direction of the side sheltered from the wind (lee side) and into the direction to the side facing towards the wind (weather side) during positioning the point of application of force in the opposite direction, thus behind the lateral centre of pressure (always viewed in the direction of motion).
By influencing the position of the point of application of force of the sheet element orthogonally to the longitudinal axis and direction of motion, respectively the heeling can be selectively influenced in a completely compensated manner. Thus, in certain cases even a negative heeling can be met if the point of application of force has been displaced quite far in the direction of the side sheltered from the wind, for example.
In addition to the already mentioned elements for varying the effective lengths of the stay rope(s) additional deflection pulleys can be disposed between the point of application of force and the sheet elements. The stay ropes can be deflected through these deflection pulleys which is favourably effecting during the variation of position of the point of application of force, on the one hand. These deflection pulleys can also be displaced, on the other hand, whereby a unique and additional variation of length of a plurality of stay ropes can be achieved in a relatively simple manner and without any required actuating forces.
For a sail-shaped and kite-shaped sheet element, respectively which has been stretched in a two-dimensional manner using the already mentioned compressed gas containing chambers if possible, the most different geometric forms can be employed wherein optimizing the shapes of the sheet elements for the respective application can also be carried out under consideration of the design of the body of the watercraft used.
For a sufficient manoeuvrability of the sheet element it is advantageous to use at least three stay ropes being variable in its effective length independently from each other, which are attached to the body of the watercraft and to the sheet element then. Mounting on the sheet element is achieved such that the three mounting points of the stay ropes are spanning a triangle, and thus with lengthening and shortening, respectively the effective lengths of the three stay ropes the sheet element can be moved both in horizontal and vertical directions as well by means of the attacking wind force, and in addition the angle of attack is variable with respect to the prevailing wind direction.
It is more favourably to use four stay ropes which provide the connection between the sheet element and the body of the watercraft. On that occasion, the four stay ropes are attached to the sheet element such that the mounting points are spanning a square, if possible, wherein each two mounting points are in a common horizontal plane, and the other two mounting points are in a vertical plane. For manoeuvring the sheet element at least lengthening and shortening, respectively of a stay rope is required. However, the stay ropes which mounting points are on the sheet element in a plane can also be lengthened and shortened with the same length if possible in opposite direction each. If this modification will be selected, the actuation power each required can be correspondingly reduced such that manual actuating is readily possible.
With the invention the keel constructions being common for watercrafts heretofore, first are allowed to be smaller dimensioned and even more substituted by more cost effectively leeboards since the turning moments acting about the longitudinal axis will be significantly reduced.
Application in average situations is also possible, e.g., if with a conventional sail ship or sailing boat a mast has been broken and a wind propulsion according to the invention which is onboard can be rapidly and simply employed and provide the propulsion and manoeuvrability.
In additions it is advantageous to provide at least one hydrodynamically effective element, which can also be designated with the term “hydrofoil”, on the body of the watercraft. On that occasion, such an element is located beneath the floating line on the body of the watercraft and allows stabilizing the watercraft during the progressive movement.
It is more especially advantageous that such a hydrodynamically effective element can be pivoted about an axis such that a lift force or a depression force can be adjusted for the watercraft.
However, these hydrodynamically effective elements should be arranged such that symmetrical force relations occur with respect to the longitudinal axis of the watercraft. Thus, for example, two such elements can be arranged in the same level on the two outer sides of the body of the watercraft.
Favourably, the pivoting angle of the hydrodynamically effective elements can also be adjusted depending on the vehicle speed and/or tensile force of the sheet element. In particular, during immediately occurring gusts of wind, thus it can be ensured that the body of the watercraft will be carried in the water also during extreme situations. With this, the pivoting angle of the hydrodynamically effective elements can be adjusted by a mechanical coupling by means of the tensile force acting on the stay ropes or point of application of force.
These elements are allowed to be formed similar to wings and either aligned horizontally or in an angle slightly inclined toward the horizontal.
The aerodynamic properties of the sheet element can be influenced by effecting the three-dimensional form which can be achieved by means of the stay ropes, and if the case may of additional stay ropes. In addition, supplementary aerodynamically effective elements can be attached to the sheet element. These aerodynamically effective elements are allowed to be pivotally secured on the sheet element and formed in a flap shape, for example, such that being more or less put upright they cause lift or side forces on the sheet element effected by the correspondingly increased flow resistance against the attacking wind according to the adjusted angle and the corresponding arrangement, and thus allowing for the position of the sheet element to be manipulated with respect to the body of the watercraft and the wind direction. The adjustment of the pivoting angle of these aerodynamically effective elements can be achieved by means of equivalent ropes as well, for example, which are guided toward the body of the watercraft.
It can also be of advantage if airflow breakaway elements (winglets) are provided on the outer edges of the sheet element which are allowed to cause an improvement of the aerodynamics as well.
To avoid situations of danger additional elements protecting from overload can be used. These elements ensure that with exceeding a predeterminable maximum tensile force on the one or a plurality of stay ropes this force cannot attack on the body of the watercraft in full size. A possibility to oppose these overload conditions is in that to provide the stay ropes with a spring, a damper or a spring damping system wherein the spring and damper characteristics should be adjusted such that the equivalent spring or damping forces become effective until exceeding the threshold already mentioned, and for example a tension spring having a degressive spring characteristic should be selected such that the correlative tensile forces of such an element protecting from overload can be reduced again.
Another alternative for an element protecting from overload is in the use of sliding clutches which are provided at winches, for example, to influence the length of the stay ropes as the case may be.
Another advantageous aspect of the watercraft according to the invention can be equipped with a manipulable leeboard. Such a leeboard is allowed to be reciprocated in the vertical direction such that the effective area can be adjusted as the occurring heeling on the vehicle according to the invention can be completely, however, at least largely compensated.
However, such a leeboard can also be deflected with respect to the longitudinal axis of the body of the watercraft such that it is allowed to completely take over or support the function of a conventional rudder. In addition, with such a leeboard it is allowed to go higher by the wind (more height running).
To increase the safety at least one sensor string can be attached to the sheet element which is guided therefrom to the body of the watercraft. By means of these sensor strings with touching them the propulsion of the watercraft can be influenced, and such propulsion can be drastically reduced by the correlative influence of the aerodynamically effective surfaces and shape of the sheet element in a very short time. Preferably, two sensor strings can be attached to the outer edges of the sheet element.
Controlling a watercraft according to the invention can be facilitated by different ways and completely automated with adequate expense as well.
Thus, measured values detected with various sensors can be processed in control electronics, and at least the position of the sheet element can be influenced with respect to the desired direction of motion and wind direction with this control electronics.
However, controlling a vehicle according to the invention, can also be influenced purely mechanically in a relatively simple manner with sling elements for stay ropes which are provided on the body of the watercraft.
With these sling elements for stay ropes which are arranged on the body of the watercraft between the respective mounting point of the corresponding stay rope and the sheet element, influencing the position of the sheet element can be achieved. In the most simple case a sling element for stay ropes is allowed to be a vertically aligned rod attached to the body of the watercraft which the laterally drifting stay rope abuts against during equivalent movement of the sheet body which results in a relatively shortening of the stay rope which prevents a further movement of the sheet element into the direction which is not desired.
However, a sling element for stay ropes can also be designed in the form of a hoop which is attached to the body of the watercraft. The respective stay rope is guided through this hoop such that an abutting limit is provided on both sides in the horizontal direction and upwardly in the vertical direction.
The sheet element for a watercraft according to the invention is allowed to comprise at least one compressed gas containing chamber. The compressed gas containing chamber can be a part of the sheet element or be connected with the sheet element. Such a compressed gas containing chamber should be able to be charged from a gas accumulator tank in which compressed gas being preferably helium is contained via a first conduit which is connected and can be connected to the compressed gas containing chamber, respectively. On that occasion, a defined gas volume is to be filled in into the compressed gas containing chamber which is sufficient to effect a lifting force for the complete sheet element which should be greater than or equal to the component of the gravitational force of the sheet element.
The connection between the compressed gas accumulator which can be a conventional gas bottle, and the compressed gas containing chamber on the sheet element can be achieved by a valve and can be disconnected therefrom again. Then, the valve can be arranged in close proximity on the outlet of the compressed gas accumulator but also in the first conduit, and can be manually opened and closed in a most simple manner.
However, a valve which automatically closes depending on the internal pressure in the compressed gas containing chamber can also be employed with reaching a predeterminable internal pressure.
For recirculating gas from the compressed gas containing-chamber at least a second conduit should be present which in an alternative is passing in parallel to the first conduit already mentioned, and which can also be connected to the at least one compressed gas containing chamber wherein this second conduit is allowed to lead into a second compressed gas accumulator or into a second port of that one compressed gas accumulator connected to the compressed gas containing chamber as well.
However, the second conduit has not to be absolutely connected in close proximity with a compressed gas containing chamber, but it is also allowed to be connected to the first conduit wherein the port to the first conduit can be achieved through a so-called T-piece.
The second conduit can also represent a by-pass around the valve already mentioned to the first conduit, however, wherein in this case the gas recirculated from the compressed gas containing chamber is to be carried into the one compressed gas accumulator.
As a rule, at least in such cases in which the recirculated gas is to be carried into the gas accumulator which has also been used for charging the compressed gas containing chamber, in the second conduit a compressor can be disposed the induction side of which is connected to the portion of the second conduit towards the compressed gas containing chamber, and the delivery side of which is connected to the portion of the second conduit which communicates with the gas accumulator.
Compressors in the most different well-known forms are possible, however, wherein on the delivery side a gas pressure should be available by means of which it is ensured that the compressed gas accumulator can be charged again with the recirculated gas.
In the most simple cases manually actuated compressors such as hand pumps or piston compressors can be employed.
If two gas accumulators are used, then the second gas accumulator into which the gas from the compressed gas containing chamber is again recirculated can be differently dimensioned such that inside thereof a relatively low internal pressure occurs with the recirculated gas wherein the already mentioned compressor can be abandoned as the case may be.
The recirculated gas temporarily stored in the second compressed gas accumulator is thus allowed to be recirculated from this second compressed gas accumulator into a first compressed gas accumulator and to be compressed higher at any times by means of an equivalent compressor.
The first conduit already mentioned can be temporally connected to the compressed gas containing chamber for charging and recirculating the gas wherein in this case a lockable connecting branch should be provided on such a compressed gas containing chamber.
As the required internal pressures in the compressed gas containing chamber are relatively low, however, it is also possible to stationarily connect a relatively weak dimensioned first conduit having a low mass to the compressed gas containing chamber such that the first conduit with a sufficient length has not to be separated from the sheet element during the progressive movement of the watercraft.
The first conduit should be made of flexible material not only in this case such that handling is facilitated.
However, the first conduit connecting the compressed gas containing chamber and a compressed gas accumulator can also be guided as a by-pass around a compressor wherein the gas stream can be guided through this first conduit or the compressor by means of at least one two-way valve. The second conduit can be formed in this case by the compressor with its two ports. The first conduit can be guided through the compressor housing.
The compressed gas accumulator utilized at least for charging the one and also a plurality of compressed gas containing chambers, respectively should have an internal pressure of gas before and during charging which is greater than or equal to the required internal pressure in the pressure chamber and in the pressure chambers, respectively.
All the components required for charging and recirculating the gas are allowed to be carried with the wind-propelled watercraft such that replenishing the compressed gas containing chamber is also possible during the further movement. At least one of the compressed gas accumulators should be able for this to be attached to the vehicle wherein the attachment should be formed such that the equivalent compressed gas accumulator can be carried separately of the vehicle to a tank installation for replenishing with gas.
In the following, the invention shall be explained in more detail according to embodiments in which
FIG. 1 shows an embodiment of a sheet element which can be employed on a watercraft according to the invention;
FIG. 2 shows another embodiment of a sheet element having a kite shape;
FIG. 3 illustrates a top view upon a body of the watercraft with an embodiment for a wind propulsion according to the invention;
FIG. 3a illustrates an enlarged section X from FIG. 3;
FIG. 3b shows a jib boom which can be employed with the embodiment according to FIG. 3;
FIG. 4 illustrates a top view of another embodiment with a body of the watercraft;
FIG. 4a shows the enlarged section Y from FIG. 4;
FIG. 4b shows an embodiment of an element suitable for varying the length of stay ropes;
FIG. 5 shows a top view of another embodiment for carrying out guides on a body of the watercraft;
FIG. 5a shows a sectional view along A-A from FIG. 5;
FIG. 5b illustrates the section Z as an enlargement from FIG. 5a;
FIG. 6 shows another embodiment of wind propulsion in a top view;
FIG. 7 shows a top view upon a body of the watercraft having a jib boom for varying the point of application of force;
FIG. 7a shows a front view upon an embodiment according to FIG. 7;
FIG. 7b shows the enlargement of the sections W and W′ from FIG. 7a;
FIG. 8 shows a top view upon-another embodiment of a wind propulsion; FIG. 8a shows a side view of FIG. 8;
FIG. 9 shows a diagrammatic view of an embodiment of a wind propulsion on a sailing boat;
FIG. 10 shows a top view upon a diagrammatically illustrated body of the watercraft;
FIG. 11 shows three embodiments of modification for sheet elements and the possible alignment thereof toward the wind;
FIG. 12 shows three embodiments for adjusted forms of a sheet element under consideration of the wind force;
FIG. 13 shows a diagrammatic view of a sheet element having aerodynamically effective elements;
FIG. 14 shows a diagrammatic view of a sling element for stay ropes disposed on a body of the watercraft in three views;
FIG. 15 shows diagrammatically a body of the watercraft which is connected to a sheet element by means of a stay rope;
FIG. 16 shows an embodiment of a sheet element comprising a compressed gas containing chamber and a connecting branch;
FIG. 17 shows the structure of an embodiment of a gas supply and recirculation according to the invention in a diagrammatic form;
FIG. 18 shows a second embodiment of a gas supply and recirculation according to the invention;
FIG. 19 shows a third embodiment of a gas supply and recirculation to be used according to the invention;
FIG. 20 shows an embodiment of a gas supply and recirculation to be used according to the invention with two gas accumulators.