CATAMARAN CRAFT

The present invention relates to a catamaran craft of the type specified in the preamble of the first claim.

In the last few years, the use of catamaran craft has become more and more widespread, in other words, means made up of two hulls and a structure connecting the two hulls, for transporting people and/or objects.

Level with the stern of each hull, usually, the catamaran crafts are fitted with an engine and a propeller for the thrust and a corresponding rudder for the manoeuvre.

The known art, stated above, presents a number of important disadvantages. One first important disadvantage is represented by the fact that the flow of water impacting the propellers of the engines is not optimum, as it is disturbed by the careening of the hulls. This results in a reduced performance of the propellers themselves and, consequently, a reduced thrust.

Another disadvantage related to the nature of the particular type of bottom is the limited manoeuvrability that characterises these types of catamaran crafts. Said disadvantage is particularly evident if we consider the reduced dimensions of canals or other waterways where catamaran crafts might be used.

In this situation, the technical task at the basis of the present invention is to design a catamaran craft that is substantially capable of overcoming the stated disadvantages.

Within the context of said technical task, an important object of the invention is to have a catamaran craft characterised by elevated simplicity in terms of manoeuvrability. Another object of the invention is to design a catamaran craft that guarantees greater propeller performance, with the same power installed, thanks to its improved positioning.

The technical task and the stated objectives are achieved with a catamaran craft for inland waters, as claimed in the accompanying Claim 1 .

Preferred embodiments are highlighted in the dependent claims.

The characteristics and advantages of the invention are clarified below by a detailed description of preferred embodiments of the invention, with reference to the accompanying figures, wherein:

Figure 1 shows a catamaran craft according to the invention;

Figure 2 illustrates a second view of the catamaran craft in Figure 1 ;

Figure 3 presents another catamaran craft according to the invention;

Figure 4 is a second view of the catamaran craft in Figure 3; and

Figure 5 shows another catamaran craft according to the invention.

In this document, when measurements, values, shapes and geometrical references (such as perpendicularity and parallelism) are associated with words, such as "approximately" or other similar terms, such as "practically" or "substantially", they shall be understood as without errors of measurement or inaccuracies resulting from production and/or manufacturing errors, and above all, without a slight divergence from the value, measurement, shape or geometrical reference which it is associated with. For example, if such terms are associated with a value, they preferably indicate a divergence of no more than 10% of the same value.

Furthermore, when terms such as "first", "second", "greater", "lower", "principal" and "secondary" are used, they do not necessarily identify an order, a relationship priority or relative position, but they may simply be used to distinguish different components more clearly.

With reference to the stated Figures, the catamaran craft according to the claim is globally indicated with number 1 .

It defines a bow 1 a, a stern 1 b and a main barycentric extension axis 1c.

It comprises two hulls 2, which are spaced out and opportunely placed symmetrically in relation to the axis 1 c. Said hulls can be substantially identical. Each hull 2 presents both ends with a shape of a known type and, in particular, tapered so as to assist the movements of the craft 1 in at least one direction, and in particular, in both directions. Alternatively, the hulls 2 have one end, preferably the bow 1 a, tapered and the other end, preferably the stern 1 b, not tapered, and for precision, ending with a flat side that is opportunely practically perpendicular to the barycentric axis 1 c.

The hulls 2 can have a minimum wave resistance, in other words they can have such geometries as to have a minimum wave resistance.

It is highlighted how the craft 1 and, in particular, the hulls 2 are without connectors or other similar means suitable for constraining the hulls 2 and, consequently the catamaran craft 1 , to additional catamaran crafts, in an opportunely stable manner.

The catamaran craft 1 comprises a deck 3 connecting the hulls 2 and, preferably, a superstructure 4 defining a collection area, together with the deck, for transporting objects and/or people, which is opportunely made up of side walls and a cover.

The deck 3 is joined between the hulls 2 and therefore, integrally constrains the hulls to each other 2. It defines a support surface 3a for the transport of objects and/or people. In particular, the deck 3 is flat and defines a flat support surface 3a.

The deck 3 and, in particular, the support surface 3a are substantially parallel to the main barycentric extension axis 1 c.

The catamaran craft 1 comprises at least one azimuth thruster 5, which is suitable for moving the catamaran craft 1 ; at least one rudder 6, opportunely a blade, suitable for directing the craft 1 ; and, opportunely, a sailing station 7 connected to the thruster 5 and/or to the rudder 6 so as to control the direction and travel speed of the craft 1 .

The catamaran craft 1 can comprise only one azimuth thruster 5 (Figures 1 -4). Alternatively, the catamaran craft 1 can comprise several azimuth thrusters 5 and preferably two azimuth thrusters 5.

An azimuth thruster 5 is constrained to said deck 3 and comprises at least one propeller 51 defining a thrust axis 5a for the catamaran craft 1 ; a pod 52 supporting the propeller 51 and housing opportunely the engine of said propeller 51 (alternatively, the engine can be on the deck and fitted with a kinematic system to transmit motion to the propeller 51 )t; a rotation group suitable for rotating around a rotation axis 5b, at least the pod 52 and the propeller 51 in relation to the deck 3; and at least one connecting element 53 constraining the pod 52 to the rotation group.

The pod 52 and the propeller 51 are suitable for being submerged, at least partially, in water when the catamaran craft 1 is sailing.

The connecting element 53 can comprise a section bar, usually called a nozzle, with an opportunely circular section and preferably hollow. Alternatively, it comprises a plate, with an opportunely ogival section, or, in another preferred alternative, it comprises a section bar and a blade. A further alternative consists of a double blade or a double profile.

The rotation group is integral with the deck 3.

It is suitable for rotating at least the pod 52 and the propeller 51 varying the tilt of the thrust axis 5a in relation to the main barycentric extension axis 1 c.

Additionally, it is suitable for rotating the connecting element 53.

The rotation group defines a rotation axis 5b that is substantially perpendicular to the barycentric axis 1 c so as to rotate the pod 52 varying the tilt angle between the thrust axis 5a and the barycentric axis 1 c, keeping the tilt between the thrust axis 5a and the support surface 3° constant.

In some cases, the thruster 5 can comprise a regulator, for example in accordance with a command given from the sailing station 7, for the tilt of the thrust axis 5a, which is suitable for varying the tilt between the rotation axis 5b and the support surface 3a.

Such regulator is suitable for rotating the pod 52 and the propeller 51 in relation to a regulation axis that is practically perpendicular to the rotation 5b and thrust axis 5a. Opportunely, the regulation axis is practically parallel to the support surface 3a.

Optionally, the azimuth thruster 5 and, in particular, the connecting element 53 are suitable for varying, for example in accordance with a command given from the sailing station 7, the distance of the thrust axis 5a from the support surface 3a thus adjusting the submersion depth of the pod 52 and the propeller 51 . In these cases, the connecting element 53 can be telescopic to vary said distance modifying its own extension along an extension axis that is substantially perpendicular to the support surface 3a and in particular substantially parallel to the rotation axis 5b.

Alternatively, leaving the element 53 fixed and unchanged, the craft 1 allows the whole thruster 5 to be moved vertically by the kinetic system fixed in the hull constraint area.

The catamaran craft 1 can comprise a log or some other device, such as a gps, for example, which is suitable for measuring the speed of the catamaran craft 1 . Said log is opportunely connected to the azimuth thruster 5 to allow the submersion depth of the pod 52 and the propeller 51 to be adjusted according to the speed of the catamaran craft 1 . In particular, the log is suitable for controlling a variation of said depth that is directly proportionate to the speed variation of the catamaran craft 1 .

The catamaran craft 1 can comprise a regulating device for the position of the azimuth thruster 5 in relation to the deck 3, which is suitable, in particular, for varying the distance between the thruster 5 and the rudder 6 along the barycentric axis 1 c.

The regulating device can be controlled according to a command given from the sailing station 7.

The regulating device is suitable for moving the azimuth thruster 5 and\or the rudder 6 in relation to the deck 3 along a regulating axis that is substantially parallel to the main barycentric extension axis 1 c.

The regulating device can comprise at least one guide, for example dovetail shaped, that is integral with the deck 3 and defines the regulating axis; and at least one slider, which is integral with the azimuth thruster 5 or the rudder 6 (preferably the thruster 5) that is suitable for sliding along said guide.

In particular, in the event of moving the azimuth thruster 5, the regulating device comprises two guides placed on opposite sides in relation to the rotation group; and, for each guide, two sliders constrained integrally with the rotation group.

It should be noted that in the event of moving the thruster 5 and the rudder 6, the regulating device can comprise, in addition to the at least one guide, at least a first slider integral with the azimuth thruster 5 and at least a second slider integral with the rudder 6; wherein said at least first slider and said at least second slider are suitable for sliding, preferably independently, along said guide.

The azimuth thruster 5, as described above, and the rudder 6, as described below, are placed along the main barycentric extension axis 1 c and are, therefore, equally spaced out from the hulls 2.

The catamaran craft 1 can comprise only one rudder 6 (Figures 1 -4).

Alternatively, the catamaran craft 1 can comprise a number of rudders 6, and preferably two rudders 6 (Figure 5).

One rudder 6 is constrained to the deck 3 or to a hull 2 and is suitable for being at least partially submerged in water so that, if opportunely controlled by the operator from the sailing station 7, it directs the catamaran craft 1 together with the azimuth thruster 5.

It defines a lying plane that is substantially perpendicular to the support surface

3a.

The rudder 6 can be constrained loosely to the deck 3 or to the hull 2 so as to rotate in relation to it, varying the tilt of the lying plane of the rudder 6 in relation to the main barycentric extension axis 1 c.

Thus, it can comprise a control member suitable for controlling the rotation of the rudder 6 around an additional rotation axis 6a defining a plurality of positions wherein the lying plane of the rudder 6 is transversal or parallel to the main barycentric extension axis 1 c.

The additional rotation axis 6a is practically normal to the main barycentric extension axis 1 c and, therefore parallel to the rotation axis 5b.

Innovatively, the azimuth thruster 5 and the rudder 6 are placed at opposite ends in relation to a barycentric transversal plane 1d, which can be identified as a plane that is perpendicular to the main barycentric extension axis 1 c, passing through the barycentre of the catamaran craft 1 .

In particular, the thruster 5 is accessible near the bow 1 a and the rudder 6 near the stern 1 b (Figures 1 and 2). Alternatively, the thruster 5 is accessible near the stern 1 b and the rudder 6 near the bow 1 a (Figures 3 and 4).

It should be noted how, in the case of two azimuth thrusters 5, they can be accessible on opposite sides in relation to the barycentric extension axis 1 c and opportunely equally spaced out from the main barycentric extension axis 1 c itself. In particular, if they are near the bow 1 a, the two azimuth thrusters 5 can be placed in front of the hulls 2, whereas, if they are near the stern 1 b, the two azimuth thrusters 5 can be placed behind the hulls 2.

In the case of two rudders 6, they can be accessible on opposite sides in relation to the barycentric axis 1 c and equally spaced out from the main barycentric extension axis 1 c itself. In particular, if they are near the bow 1 a, the two rudders 6 can be placed in front of the hulls 2, whereas, if they are near the stern 1 b, the two rudders 6 can be placed behind the hulls 2.

It should also be noted that the catamaran craft 1 can comprise only one rudder 6 and only one azimuth thruster 5 (Figures 1 -4). Alternatively, the catamaran craft 1 can comprise only one rudder 6 and two azimuth thrusters 5. In another alternative, the craft 1 can comprise two rudders 6 and only one azimuth thruster 5 (Figure 5). In a further alternative, the catamaran craft 1 can comprise two rudders 6 and two azimuth thrusters 5.

Preferably, the axes 5b and 6a are substantially perpendicular to the support surface 3a. In particular, in the case of only one axis 5b and only one axis 6a, the axes 1 c, 5b and 6a lie on one same plane, perpendicular to the support surface 3a.

The azimuth thruster 5 and the rudder 6 and, for precision, the additional rotation axis 6a and the rotation axis 5b have different distances from the barycentric transversal plane 1 d. Alternatively, the azimuth thruster 5 and the rudder 5e, preferably, the additional rotation axis 6a and the rotation axis 5b have substantially the same distance from the transversal barycentric plane 1 d. The sailing station 7 is suitable for controlling the azimuth thruster 5, the rudder 6 and, in some cases, the regulator.

It is preferably suitable for controlling the rotation of the azimuth thruster 5 around the rotation axis 5b and the rotation of the rudder 6 around the additional rotation axis.

In particular, it is suitable for controlling a rotation of the rudder 6 in relation to the additional rotation axis 6a and a rotation of the azimuth thruster 5 in relation to the rotation axis 5b, which are simultaneous and have speeds of the same breath and opposite direction, so that the rudder 6 and the thrust axis 5a adopt angles of the same breath and opposite direction in relation to the barycentric axis 1 c.

Alternatively, the sailing station 7 is suitable for controlling a rotation of the rudder 6 in relation to the additional rotation axis 6a and a rotation of the azimuth thruster 5 in relation to the rotation axis 5b, which are different and, in particular, not simultaneous and/or have different speeds, so that the rudder 6 and the thrust axis 5a define different angles in relation to the barycentric axis 1 c.

The operation of the catamaran craft, described above, in terms of movement dynamics, is as follows.

When the operator has to make a turn or some other change in the travelling direction of the catamaran craft 1 , he imparts a rotation of the azimuth thruster 5 and, preferably, of the rudder 6 from the sailing station 7.

In particular, to optimise the tacking angle in relation to the bend, the operator can control a rotation of the azimuth thruster 5 around the rotation axis 5b and of the rudder 6 around the additional rotation axis 6a.

Such double rotation makes it possible to vary both the tilt of the thrust axis 5a and the tilt of the lying plane of the rudder 6 in relation to the barycentric axis 1 c, to exploit both the action of the thruster 5 and that of the rudder to control said rotation\turn.

Such double rotation can have equal, opposite and/or different breaths.

Note how, as an alternative to said double rotation, the operator can control a rotation solely of the azimuth thruster 5 around the rotation axis 5b or of the rudder 6 around the additional rotation axis 6a.

The invention presents important advantages.

One first, important advantage is represented by the fact that, as the azimuth thruster 5 and the rudder 6 are placed far from the hulls 2 and, in detail, on opposite sides to the transversal barycentric plane 1 d, they are hit by an optimum flow of water and thus offer greater efficiency, consequently making maximum use of the thrust action of the azimuth thruster 5 and the guiding action of the rudder 6.

Furthermore, said arrangement means that the flow coming out from the rudder 6 and/or the azimuth thruster 5 doesn't alter the flow going into the thruster 5 and/or rudder 6.

Additionally, as the azimuth thruster 5 and the rudder 6 are placed along the longitudinal axis 1 c, they are incidentally hit by a flow of water that is not disturbed, or only slightly, by the hulls 2.

Another advantage is given by the regulating device. By enabling the position of the azimuth thruster 5 to be adjusted along the barycentric axis 1 c, it allows it to be adapted to that of the load of the catamaran craft 1 .

A further advantage is given by the possibility of varying the submersion depth of the propeller 51 , making it possible to optimise the efficiency of the propeller 51 itself according to, for example, the conditions of the sea.

Optimisation is also given by the fact that adjusting the position of the propeller in depth allows the propeller to be positioned correctly in relation to the central wave, which is created between the hulls during the travelling phase and can be varied depending on the speed.

In particular, control of the depth according to the speed of the craft 1 means it is always possible to have the right submersion depth, also when said speed is varied.

Another advantage is given by the presence of several rudders 6 and, in particular, two rudders 6. In fact, this technical solution guarantees greater manoeuvring efficiency for the catamaran craft 1 thanks to the increased torque transmitted by the two rudders 6. Furthermore, having two rudders 6 means their size can be reduced as a result of their increased overall efficiency.

The invention is subject to variations that lie within the sphere of the inventive concept described in the independent claims and relative technical equivalents. In this context, all of the details can be replaced by equivalent components and any materials, shapes and sizes may be used.