WO2015028985A1

WO2015028985A1 - Naval unit able to remain and move submerged and on the surface

Info

Publication number: WO2015028985A1
Application number: PCT/IB2014/064153
Authority: WO
Inventors: Andrea Antonio AGRUSTA
Original assignee: DO', Tiziano
Priority date: 2013-08-30
Filing date: 2014-08-29
Publication date: 2015-03-05
Also published as: ITUD20130110A1

Abstract

A naval unit configured to selectively assume both a surface condition and a submerged condition comprises a spindle-shaped main body (11) which has a bottom (15) that develops between a first zone (11a), comprised between a rear stern end (13) and the center line (I), and a second zone (11b), comprised between the center line (I) and a front bow end (12). At least one portion of the bottom (15) provided in the first zone (11a) is provided with a first rounded concave cross section and having a profile defined by a continuous curve, and at least another portion of the bottom (15) provided in the second zone (11b) is configured planing, having a second cross section with a profile defined by two segments (215) converging toward a common vertex (W).

Description

"NAVAL UNIT ABLE TO REMAIN AND MOVE SUBMERGED AND ON THE SURFACE"

* * * * *

FIELD OF THE INVENTION

5 The present invention concerns a naval unit, a craft or similar boat, able to remain and move submerged and on the surface.

In particular, the present invention concerns perfecting the relative geometries of said naval unit, or craft, intended as shapes and functioning dimensional parameters.

10 BACKGROUND OF THE INVENTION

Among naval units, submersible craft are known, indicated hereafter as "submersibles" only, designed to remain and move both on the surface and submerged.

"Submarines" are also known, that is, naval units, generally with atomic oi^¬ l s electric propulsion, expressly designed for highly autonomous navigation, either submerged or on the surface.

Both submersibles and submarines generally have a hydrodynamic shape that is also configured to support the possible strong pressures typical of underwater depths. These naval units, when on the surface, can remain with at least 50% of 20 their total volume immersed.

It is also known that planing craft are normally used for pleasure boat navigation, which are naval units able to emerge from the water for most of their volume, thus minimizing the resistance of the water during their motion.

These boats are generally light, even in a condition of static floating they are 25 not deeply immersed, they have shapes with angular geometries and they are highly lifting: this makes them even lighter during sailing.

One disadvantage of known submersibles and submarines is that they are incompatible with planing in a surface condition, while one disadvantage of planing boats is that they are incompatible with submersion and therefore not 30 able to proceed in a submerged condition.

The above incompatibilities are essentially linked to the specific conformations, conceptually very different, that a naval unit must have depending on its different uses. Documents US 3,463, 108 A and US D475,964 S I show naval units able to move submerged and on the surface having a bottom with a variable cross section.

On the basis of the above, it is clear that the needs of geometric stability during submersion, on the surface or planing, as well as the needs for forward resistance and hydrodynamism, are so different as to make the shapes mentioned above incompatible and not applicable to a single naval unit.

There is therefore the need to perfect a naval unit able to remain and move submerged and on the surface that can overcome at least one of the disadvantages of the state of the art.

It is in this perspective that the present invention proposes the purpose of making a naval unit, such as a submersible, with functional geometries that guarantee the correct hydrostatic and hydrodynamic functioning thereof both on the surface and submerged, and at the same time enable the naval unit to plane on the surface of the water in the surface condition.

In particular, purposes of the present invention are to make a naval unit able to:

- plane in the surface condition,

- have sufficient static and dynamic stability both submerged and on the surface, - have sufficient reserves of static stability in the surface condition in the event of a transverse movement of the load, as well as any abrupt variation thereof,

- have a correct navigation trim, both in the submerged condition and in the surface condition, and therefore both in the event of displacement, that is, the movement of masses of water during motion, and also in the event of planing, that is, motion almost resting on the surface of the water,

- avoid uncontrolled rotational effects during submersion due to the motion of the propeller or abrupt maneuvers,

- minimize the power necessary to reach the desired speeds, both planing during surface navigation and during submerged navigation,

- have a good sea-keeping when in the surface condition.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages. SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claim, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purposes, a naval unit according to the present invention is configured to selectively assume both a surface condition and a submerged condition, and comprises a spindle-shaped main body which has a bottom that develops between a first zone, comprised between a rear stern end and the center line, and a second zone, comprised between the center line and a front bow end.

According to one aspect of the present invention, at least one portion of the bottom provided in the first zone is provided with a first rounded concave cross section and having a profile defined by a continuous curve. At least another portion of the bottom provided in the second zone is configured planing, and has a second cross section delimited by a profile defined by two segments converging toward a common vertex.

In this way, the naval unit according to the present invention is hydrodynamic both in the surface condition and in the submerged condition, and is able to remain and move in both conditions, as well as to proceed in the surface condition with a planing motion.

In some forms of embodiment, the portion of bottom of the first zone is adjacent to the second zone of the main body.

According to the present invention, the main body comprises a third zone, intermediate between the first zone and the second zone, in which the bottom has a third cross section, with a mixed profile between the first cross section and the second cross section, configured to connect, continuously and progressively, the first cross section and the second cross section.

This gradual passage, continuous and connected, in a mixed connection zone, advantageously confers further hydrodynamism to the naval unit in question, giving geometric continuity in the transition zone between the different types of section.

According to the present invention, along its lateral sides the bottom comprises a shoulder defined by a planar surface facing toward the bottom part of the bottom.

The shoulder allows the naval unit to plane with correct dynamic trim and with the desired stability.

In some forms of embodiment, the bottom of the main body of the naval unit according to the present invention comprises, in proximity to the rear end, a hollow conformed as a step, through in a transverse direction with respect to the longitudinal axis and delimited by a first flat surface and a second flat surface, reciprocally inclined and intersecting in a horizontal segment.

The hollow has the advantage that it truncates the geometries of the bottom of the main body in its rear zone, thus allowing the naval unit according to the present invention to have high dynamic performances when planing.

According to features of the present invention, the naval unit comprises at least two lateral appendixes having a winged profile and protruding laterally from the main body symmetrically with respect to the longitudinal axis.

The lateral appendixes are configured to guarantee static stability to the naval unit in the surface condition, preventing rolling, conferring hydrodynamism during planing, as well as preventing spinning of the naval unit in the submerged condition or in the submersion steps.

According to features of the present invention, the lateral appendixes are disposed attached on the main body.

In accordance with some forms of embodiment, the first cross section can be a U-shaped cross section.

In accordance with some forms of embodiment, the second cross section can be a V-shaped cross section.

These and other aspects, characteristics and advantages of the present disclosure will be better understood with reference to the following description, drawings and attached claims. The drawings, which are integrated and form pail of the present description, show some forms of embodiment of the present invention, and together with the description, are intended to describe the principles of the disclosure.

The various aspects and characteristics described in the present description can be applied individually where possible. These individual aspects, for example aspects and characteristics described in the attached dependent claims, can be the object of divisional applications.

It is understood that any aspect or characteristic that is discovered, during the patenting process, to be already known, shall not be claimed and shall be the object of a disclaimer.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of some forms of embodiment, given as a non- restrictive example with reference to the attached drawings wherein:

- fig. 1 is a three-dimensional view from above and from the bow of a naval unit according to the present invention;

- fig. 2 is a three-dimensional view from below and from the stern of the naval unit in fig. 1 ;

- fig. 3 is a lateral view of the naval unit in fig. 1 ;

- figs. 4a to 4e show the perimeter developments of stern portions of the naval unit in fig. 1 , corresponding to the cross sections from IVa-IVa to IVe-IVe in fig.

- figs. 5a to 5d show the perimeter developments of bow portions of the naval unit in fig. 1 , corresponding to the cross sections from Va-Va to Vd-Vd in fig. 3 ;

- fig. 6 is a lateral view of the naval unit in fig. 1 , in which design quantities are shown;

- fig. 7 is a view from below, partly sectioned, of the naval unit in fig. 1 ;

- fig. 8 is a front view from the bow of the naval unit in fig. 1 .

In the following description, the same reference numbers indicate the same parts of a naval unit according to the present invention, also in different forms of embodiment. It is understood that elements and characteristics of one form of embodiment can conveniently be incorporated into other forms of embodiment without further clarifications.

DETAILED DESCRIPTION OF SOME FORMS OF EMBODIMENT

We shall now refer in detail to the various forms of embodiment of the present invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one form of embodiment can be adopted on, or in association with, other forms of embodiment to produce another form of embodiment. It is understood that the present invention shall include all such modifications and variants.

With reference to the attached drawings, we shall now describe some forms of embodiment of a naval unit according to the present invention, which by way of non-restrictive example is a submersible 10.

The submersible 10 is configured to remain and move both in a surface condition, in which at least the main part of its volume is located outside the surface of the water, and in a submerged condition, in which the entire volume of the submersible 10 is located under the surface of the water.

According to some forms of embodiment, in said submerged condition the submersible 10 is able to reach even a depth of some tens of meters, twenty for example.

In possible solutions, the submersible 10 can be completely made, at least in its structural part, of one or more polymer materials and/or composites with high resistance and low specific weight, such as fiberglass for example.

This solution can allow to reduce the overall weight of the submersible 10 and the times and costs of producing it, since the above materials, specially fiberglass, are easily moldable and can be shaped according to specific needs. The reduction in weight also has the advantage of making both surfacing and planing in the surface condition easier.

Figs. 1 and 2 are used to describe forms of embodiment in which the submersible 10 can include a main body or hull 1 1 , essentially spindle-shaped or drop-shaped, the longitudinal extension of which is delimited by a bow 12 which defines a front end thereof, and a stern 13, opposite the bow 12 and defining a rear end of the hull 1 1.

The connecting line between the bow 12 and the stern 13 defines a longitudinal axis of development X of the submersible 10.

The hull 1 1 can have an upper part 14, that represents the part positioned outside the surface of the water in a surface condition, that is static or dynamic floating, of the submersible 10, and a lower part, or bottom 1 5, that represents the part of the hull 1 1 positioned more or less wholly under the surface of the water in the surface condition. The hull 1 1 can be hollow inside, to define a hollow chamber 16 for housing persons and/or things.

The upper part 14 can be provided with one or more hatches 17 to access the internal chamber 16, which can be closed by small doors 1 8, or other type of hermetically closing devices.

Fig. 2 is used to describe forms of embodiment in which the bottom 15 can be the planing or semi-planing type, that is, it can have a bottom part at least partly edge-shaped and sides that are normally not wet or only partly wet during sailing.

In some forms of embodiment, the bottom 15 can be shaped so as to include, for example, two lateral flanks or bulwarks 19, that define the part of the hull 1 1 located astride the surface of the water in the surface condition during floating.

The bulwarks 19 can be provided with a continuous shoulder 20, also called spray rail, that substantially defines an interruption of the curved profile of the bottom 15 in correspondence to the bulwarks 19, and that more or less affect the whole extension of the bow 12 to the stern 13.

The shoulder 20 can be defined by a planar surface facing downward, that is, toward the bottom part of the bottom 15.

In possible implementations, the transverse amplitude of the shoulder 20 can increase along the extension of the bow 12 to the stern 13.

Other forms of embodiment can provide an essentially constant or decreasing transverse amplitude of the shoulder 20 along the extension of the latter from the bow 12 to the stern 13.

In some forms of embodiment, combinable with all the forms of embodiment described here, in the zone of the stern 13 of the hull 1 1 , the bottom 15 can include a hollow 21 , which can have a step shape, substantially an upside down "L", whose concavity faces toward the outside of the bottom 15.

The hollow 21 has the function of interrupting or truncating the curved geometry of the bottom 1 5, to give, in the zone of the stern 13, a sharp-edged shape suitable to guarantee the correct performance of the submersible 10 when planing.

The hollow 21 can be defined by a first flat interruption surface 21 a and by a second flat interruption surface 21b incident with respect to each other along a horizontal segment 21 c. The hollow 21 can be made through in the bottom 1 5 in a direction transverse with respect to the longitudinal axis X, resulting in an extension of the horizontal segment 21 c from one bulwark 19 to the other.

In some forms of embodiment, the bottom 15 can include a longitudinal furrow 22, or tunnel, having a partial cone shape, open downward and orientated along a straight line parallel to the longitudinal axis X, whose base lies on the second interruption surface 21 b and whose vertex lies in a median zone of the bottom part of the bottom 15,

The longitudinal furrow 22 can increase the yield of the propulsion system, for example a propeller (not shown in the drawings), enclosing a portion in a conical or conoidal surface.

Moreover, the longitudinal furrow 22 can allow to install the propeller higher up, reducing the protrusion thereof below the bottom 15 and above all with a smaller angle of inclination with respect to the longitudinal axis X, increasing its efficiency and reducing the vertical thrust component that is unsuited for an object navigating submerged.

In accordance with some forms of embodiment, combinable with all the forms of embodiment described here, the submersible 10 can also include two lateral appendixes 23, with a winged profile and protruding laterally from the hull 1 1 . The lateral appendixes 23 have a planar and transverse geometry configured to confer static stability on the submersible 10 in the surface condition, and dynamic stability in the submerged condition. In particular, in the surface condition the lateral appendixes 23 prevent rolling and during planing they confer hydrodynamism on the submersible 10.

In the submerged condition, the lateral appendixes 23 have the function of preventing the spinning of the submersible 10, for example because of the effect of the thrust of any propellers or after determinate maneuvers.

In some forms of embodiment, the lateral appendixes 23 are disposed attached, not adjustable, on the main body 1 1.

According to possible solutions, the lateral appendixes 23 can be positioned substantially astride the join zone between the upper part 14 of the hull 1 1 and the bottom 15, in proximity to the bulwarks 19.

Figs. 2 and 3 are used to describe forms of embodiment in which two main zones of the hull 1 1 can be identified, that is, a first zone, or stern zone 1 1 a, comprised between the stern 13 and the center line I of the hull 1 1 , a second zone or bow zone 1 l b, comprised between the center line I of the hull 1 1 and the bow 12. A third transition or connection zone 1 l c astride the center line I of the hull 1 1 can be identified, between the stern zone 1 la and the bow zone 1 l b.

Fig. 3 is also used to show the positioning of a static floating line Gs, which defines the location of the surface of the water in the surface condition of the submersible 10 when it is stationary. The static floating line Gs is located in a zone lower than the center of the vertical bulk of the submersible 10, which therefore emerges from the water for more than 50% of its overall volume.

It should be noted how the bottom 15 is designed so that one end of the shoulder 20 in correspondence to the bow 12 and an entrance end of the hollow 2 1 in correspondence to the stern 13 are aligned along the static floating line Gs.

Figs. 4a to 5d show by way of example, using a plurality of cross sections succeeding each other along the longitudinal axis X, a possible development of the geometry of the bottom 1 5, symmetrical with respect to a plane of symmetry Z, vertical and passing through the longitudinal axis X of the submersible 10.

Figs. 4a to 4e are used to show a possible perimeter profile of cross sections of the stern zone 1 1 a and of the intermediate zone 1 1 c of the hull 1 1 , made on vertical planes orthogonal to the longitudinal axis X and intersecting the latter at regular intervals from the stern 13 to a median zone of the hull 1 1 .

Fig. 4a is used to describe a possible development of a first portion, or quarter, of the stern zone 1 la, in particular that nearest the stern 13, in the case where the hollow 21 is present. In correspondence to the hollow 21 , the bottom 15 has a horizontal cross section, as the first interruption surface 21 a is inclined frontally with respect to the longitudinal axis X and normally lies on a vertical plane passing through the longitudinal axis X.

Figs. 4b and 4c are used to describe a possible development of a second and a third portion of the stern zone 1 1 a in which the bottom 15 includes the longitudinal furrow 22.

In this second and third portion, the bottom 1 5 has a cross section defined by two arched segments 1 15 with concavity facing toward the inside of the hull 1 1. Both the arched segments 1 15 can have one end connected to the shoulder 20 and one end converging toward an arc with concavity facing toward the outside of the hull 1 1 and defining the profile of the longitudinal furrow 22.

Figs. 4d and 4e are used to describe possible forms of embodiment of the geometries of the bottom 15, respectively in a fourth portion of the stern zone 1 l a of the hull 1 1 and a fifth portion, made in correspondence to the center line I and therefore included in the third zone 1 1 c. These geometries can also be used, in possible alternative implementations of the solutions shown in figs. 4b and 4c, in the first and/or second and/or third portion.

In the forms of embodiment described using figs. 4d and 4e, the bottom 15 can have a rounded concave profile defined by a continuous curve, of which the arched segments 1 15 constitute two symmetrical halves with respect to the plane of symmetry Z.

The continuous curve described above can identify an essentially U-shaped concave profile, where this term indicates, in their entirety, both regular curves, such as conical curves, for example parabolas, arcs of a circumference or ellipses, or quadratic curves, and other outlines, completely curvilinear or defined by a mixed line, symmetrical with respect to the plane of symmetry Z and having, in correspondence to the latter, a horizontal tangent.

The U-shaped profile provides that the arched segments 1 1 have an extension, in a transverse direction, at least equal to its extension in a vertical direction.

Figs. 5a to 5d are used to show the perimeter development of cross sections of the bow zone 1 l b of the hull 1 1 made at regular intervals along the longitudinal axis X from the center of the hull 1 1 toward the bow 12.

These drawings allow to appreciate, in particular, the development of the geometry of the bottom 15 which, also in the portions or quarters of the bow zone l i b, has a symmetrical development with respect to the plane of symmetry Z.

This geometry, concave and sharp-edged, can be defined by two converging segments 215 that converge toward a common vertex W.

In the forms of embodiment described using figs. 5a to 5d, the vertex W belongs to the plane of symmetry Z.

This type of hull is also known as a V-shaped hull, and defines the planing zone of the bottom 15. By the terminology V-shaped hull in the present description we intend to refer to a bottom 15 the cross section of which is described by any type of symmetrical curve defined by two segments that converge toward a common point. Indeed, in a V-shaped hull, the two converging segments 215 can have any shape whatsoever, that is, they can be regular curvilinear, to define a profile of the bottom 15 with an acute arc, or pointed, or again they can have flection points, or they can be rectilinear or defined by a broken line or a mixed line.

In possible implementations, the bottom of the bottom 15 can have a rounded edge, or connected, for example by means of a connection segment, rectilinear, curvilinear, or defined by a mixed or broken line, provided that the connection segment has an extension, in a transverse direction, smaller in proportion to the extension, both along this direction and also in a vertical direction, of the two converging segments 215, thus conferring in any case a shape comparable to a V- shape on the profile of the hull.

Moreover, because of the tapered shape of the hull 1 1 , the bottom 15 narrows both from the center toward the bow 12 (figs. 4a-4e) and also from the center toward the stern 13 (figs. 5a-5d).

It is provided that in the stern zone 1 l a at least one segment of the bottom 15 contiguous to the bow zone 1 l b is U-shaped.

Moreover, solutions are possible in which the change of section from a first U- shaped section of the stern zone 1 1 a, to a second V-shaped section of the bow zone l i b is gradual, progressive and connected in the intermediate zone 1 1 c, which constitutes a mixed connection zone. This intermediate zone 1 l c, of mixed connection, with reference to the attached drawings, is essentially located astride the center line I and the section shown in fig. 4e and can have a third section with a mixed development between the first U-shaped section and the second V- shaped section.

The differentiation of the curve of the bottom 15 between the stern zone 1 1 a and the bow zone 1 l b confers on the submersible 10 a suitable lift to plane with a correct dynamic trim during navigation in the surface condition.

Moreover, the fact that the bottom 15 has different profiles, that is, rounded concave and converging in an edge or pointed, makes the submersible 10 hydrodynamic both when on the surface and in the submerged condition, in both cases allowing to reach high navigation speeds.

The U-shaped curve is typical and advantageous in submarine naval units, while the sharp edged shape is usually used in planing naval units.

Figs. 4b to 5d are also used to highlight the positioning of the shoulder 20 and the longitudinal furrow 22. In particular, the shoulder 20 contributes, in dynamic planing conditions, to confer stability on the submersible 10 and maintain the desired trim during navigation.

Fig. 6 is used to describe forms of embodiment of the submersible 10 in which the first interruption surface 21 a is inclined by a first angle a with respect to a horizontal direction, in which the first angle a can have an amplitude greater than 5°.

In other forms of embodiment, combinable with forms of embodiment described here, the second interruption surface 21b can be inclined by a second angle β with respect to a vertical direction, in which the second angle β can have an amplitude smaller than 15°.

In possible implementations, the first angle a can be bigger than the second angle β.

Solutions can also be provided in which the first angle a and the second angle β have the same amplitude.

With reference to fig. 6, the submersible 10 can have a dominant size, along the longitudinal axis X, that defines a reference length L measured between the end of the bow 12 and the end of the stern 13.

The reference length L can be, for example, comprised between about 2,000 mm and about 25,000 mm. However, one must consider that this range is only indicative of possible average forms of embodiment of the submersible 10.

In possible implementations, a maximum length of each lateral appendix 23, measured parallel to the longitudinal axis X, is indicated by F and can be comprised between 1/3 and 2/3 of the reference length L.

The winged profile of the lateral appendixes 23 can be positioned in different positions of the hull 1 1 along a direction parallel to the longitudinal axis X, provided that the front part of each lateral appendix 23 is positioned at an attachment distance S from the bow end 12 of the submersible 10 greater than or equal to 1/16 of the reference length L and smaller than or equal to 1/4 of the latter.

The result is therefore that for the attachment distance S of the more advanced portion of the attachment edge of each lateral appendix 23 from the bow end 12, the formula L/16<=S<=L/4 applies.

Figs. 6 and 7 are used to describe forms of embodiment, combinable with all the forms of embodiment described here, in which the lateral appendixes 23 have longitudinal sections, that is, along vertical planes parallel to the longitudinal axis X, symmetrical with respect to a plane parallel to the static floating plane comprising the static floating line Gs cited above.

In this specific case, by way of example and not restrictive of the present invention, the lateral appendixes 23 are symmetrical with respect to a horizontal plane passing through the connecting line between the bow 12 and the stern 13 along the longitudinal axis X.

In possible implementations, along their whole extension, the lateral appendixes 23 have an ellipsoidal section straight and symmetrical with respect to a horizontal plane, and are defined by ellipses of decreasing size toward the outside.

Fig. 8 is used to describe forms of embodiment in which the hull 1 1 of the submersible 10 has a maximum width B comprised between 1/4 and 1/3 of the reference length L.

Therefore, for the maximum width B of the hull 1 1 , the formula L/4<=B<=L/3 applies.

Moreover, having defined as Y the semi-width of the single lateral appendix, that is, the extension of the lateral appendix 23 externally with respect to the hull 1 1 from its attachment point to its end, fig. 8 can be used to describe forms of embodiment in which this semi-width Y can be comprised between half and the whole value of the maximum width B of the hull 1 1.

Therefore, for the semi-width Y the formula B/2<=Y<=B applies, from which there derives, due to what was said above, a ratio between the semi-width Y and the reference length L which can be expressed by the formula L/8<=Y<=L/3, depending on the case.

In the forms of embodiment described using fig. 8, a maximum wing aperture M of the submersible 10 can be defined, defined as the maximum distance between the ends of the lateral appendixes 23. The maximum wing aperture M is defined by the sum between the maximum width B of the hull 1 1 and the two semi-widths Y of the lateral appendixes 23 (M = B + 2Y).

Implementations can therefore be possible in which the maximum wing aperture M of the submersible 10 is comprised between half the reference length L and the whole value of the latter, that is, forms of embodiment can be provided in which the formula L/2<-M<=L applies.

Fig. 8 is also used to describe forms of embodiment in which the lateral appendixes 23, in cross section along a vertical plane orthogonal with respect to the longitudinal axis X , have the shape of an overturned hyperboloid.

In possible implementations, the lateral appendixes 23 can have cross sections, that is, made along vertical planes orthogonal to the longitudinal axis X, symmetrical with respect to a plane parallel to the static floating plane, comprising the static floating line Gs.

Solutions can also be provided in which the overturned hyperboloid shape of each of the lateral appendixes 23 has a reference angle γ, measured as inclination with respect to the horizontal direction of a straight line passing through the attachment point of the corresponding lateral appendix 23 and intersecting the latter at half its semi-width Y, comprised between 5° and 15°.

The symmetry of the lateral appendixes 23 is configured to guarantee the absence of lift thereof during navigation in the submerged condition, rendering the submersible 10 neutral from the point of view of dynamic forces. This neutrality is also guaranteed by the fact that all the parts of the submersible 10 which are outside the water in the surface condition are geometrically configured to generate, when submerged, a lift equal and contrary to that of the bottom 15.

Moreover, the application point of the lift is calibrated to give zero lift and the correct advance trim angle in the submerged condition.

Thanks to the functional geometries described above it is possible to guarantee an effective static floating on the surface in which the submersible 10 has a position and an inclination at least near to specifications and indicated in the drawings by the static floating line Gs. Moreover, the present invention allows the submersible 10 to navigate planing on the water according to a configuration identified by a dynamic floating at least near to specifications as indicated in fig. 6 with a dynamic floating line Gd.

It should also be noted that the present description has been supplied mainly parametrically, which derives from the fact that the present functional geometries are valid and functioning on any scale or affinity, on condition that the constraints determined heretofore are respected where required.

It is clear that modifications and/or additions of parts may be made to the submersible 10 as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of submersible, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

Claims

1. Naval unit configured to selectively assume both a surface condition and a submerged condition, comprising a spindle-shaped main body (11) which has a bottom (15) that develops between a first zone (11a), comprised between a rear stern end (13) and the center line (I), and a second zone (lib), comprised between the center line (I) and a front bow end (12), characterized in that at least one portion of said bottom (15) provided in the first zone (11a) is provided with a first rounded concave cross section and having a profile defined by a continuous curve, and at least another portion of the bottom (15) provided in the second zone (lib) is configured planing, having a second cross section with a profile defined by two segments (215) converging toward a common vertex (W), said naval unit comprising at least two lateral appendixes (23) having a winged profile and protruding laterally from said main body (11) symmetrically with respect to said longitudinal axis (X), which lateral appendixes (23) are disposed attached on said main body (11).

2. Naval unit as in claim 1, characterized in that said portion of bottom (15) in said first zone (11a) is adjacent to the second zone (lib).

3. Naval unit as in claim 1 or 2, characterized in that it comprises a third zone (1 lc), intermediate between said first zone ( 1 la) and said second zone (1 lb), in which the bottom (15) has a third cross section, with a mixed profile between the first cross section and the second cross section, and configured to connect, continuously and progressively, said first cross section to said second cross section.

4. Naval unit as in any claim from 1 to 3, characterized in that, along its lateral flanks (19), said bottom (15) comprises a shoulder (20) defined by a planar surface facing toward the bottom part of said bottom (15).

5. Naval unit as in claim 4, characterized in that said shoulder (20) is continuous along the lateral flanks (19) of the bottom (15) and has a transverse amplitude decreasing along its extension from said bow (12) to said stern (13).

6. Naval unit as in any claim from 1 to 5, characterized in that, in proximity to said stern (13), said bottom (15) comprises a hollow (21) conformed as a step, through in a transverse direction with respect to said longitudinal axis (X) and delimited by a first flat surface (21a) and a second flat surface (21b), reciprocally inclined and intersecting in a horizontal segment (21 c).

7. Naval unit as in claim 6, characterized in that said first flat surface (21 a) is inclined, with respect to a horizontal direction, essentially parallel to said longitudinal axis (X), by a first angle (a) having an amplitude greater than or equal to 5°.

8. Naval unit as in claim 6 or 7, characterized in that said second flat surface (21 b) is inclined, with respect to a vertical direction, essentially perpendicular to said longitudinal axis (X), by a second angle (β) having an amplitude less than or equal to 15°.

9. Naval unit as in claims 4 and 6, characterized in that, in said surface condition and in static conditions, one end of said shoulder (20) located in correspondence with the bow ( 12) of the main body ( 1 1 ), and an entrance end of said hollow (21 ) located in correspondence with the stern ( 13) of said main body ( 1 1 ) are aligned along a line of static floating (Gs) essentially parallel to said longitudinal axis (X).

10. Naval unit as in any of the claims from 1 to 9, wherein said main body ( 1 1 ) extends along said longitudinal axis (X) for a reference length (L), characterized in that, in a direction orthogonal to said longitudinal axis (X), said main body ( 1 1 ) has a maximum width (B) comprised, in a closed range of values, between 1/4 and 1/3 of said reference length (L).

1 1 . Naval unit as in any of the claims from 1 to 10, characterized in that said at least two lateral appendixes (23), with respect to vertical planes parallel to the longitudinal axis (X), have a geometry defined by longitudinal sections ellipsoidal and symmetrical with respect to a single horizontal plane parallel to said longitudinal axis (X).

12. Naval unit as in any claim from 1 to 1 1 , characterized in that said at least two lateral appendixes (23), with respect to vertical planes orthogonal to the longitudinal axis (X), have a geometry defined by an overturned hyperboloid.

13. Naval unit as in claim 12, characterized in that each of said at least two lateral appendixes (23) protrudes from said main body ( 1 1 ) for a half-width (Y) comprised, in a closed range of values, between half and the whole value of said maximum width (B) of the main body ( 1 1 ).

14. Naval unit as in claims 12 and 13, characterized in that the overturned hyperboloid shape of each of said lateral appendixes (23) comprises a reference angle (γ), measured as the inclination, with respect to the horizontal direction, of a straight line passing through an attachment point of the corresponding lateral appendix (23) and intersecting said lateral appendix (23) at half the semi-width (Y), said reference angle (γ) being comprised between 5° and 15°.

15. Naval unit as in claim 13 or 14, characterized in that it is provided with a maximum winged aperture (M), defined by the distance between the ends of said lateral appendixes (23), obtainable as the sum of said maximum width (B) and two times said half-width (Y), and having values comprised, in a closed range, between half and the whole value of said reference length (L).

16. Naval unit as in any claim from 1 to 15, characterized in that the front part of each of said lateral appendixes (23) is positioned at an attachment distance (S) from the bow ( 12) of the main body ( 1 1 ) comprised, in a closed range of values, between 1/16 and 1/4 of the value of the reference length (L).

17. Naval unit as in any claim from 1 to 16, characterized in that each of said lateral appendixes (23 ) has a maximum length (F), measured parallel to the longitudinal axis (X), comprised, in a closed range of values, between 1/3 and 2/3 of the value of the reference length (L).

18. Naval unit as in any claim from 1 to 17, characterized in that said lateral appendixes (23) are attached and not adjustable.

19. Naval unit as in any claim from 1 to 18, characterized in that said first cross section is a U-shaped cross section.

20. Naval unit as in any claim from 1 to 19, characterized in that said second cross section is a V-shaped cross section.