Patent Application
20200031429
This invention relates to a hull of a nautical vehicle, such as a boat. In particular, the said vehicle may be any type of vessel, such as a boat, a ship, a sailboat, a motorboat, a sportsboat, a yacht and even a seaplane or similar boat.
There are currently various known types of boat keels.
To describe the boats, in this document, the vertical direction marks the gravitational gradient (direction of gravity) when the boat is stationary on the water, which is in turn stationary or does not move. The longitudinal direction, perpendicular to the vertical direction, marks the direction of the progress of the boat, usually coinciding with the direction of the prevailing extension direction of the boat itself. The transverse direction is perpendicular to the longitudinal and vertical directions. The horizontal plane is the plane perpendicular to the vertical direction in which the transverse and longitudinal directions lie.
A particular type of boat is described for example in the patent documents AU-B-764670, GB-A-1025454, U.S. Pat. No. 4,091,761, EP-A-0298051, U.S. Pat. No. 6,125,781, WO-A-0179056, U.S. Pat. Nos. 3,698,342 and 6,112,687.
This type of boat comprises a bottom which, in the normal section perpendicular to the longitudinal direction, has a central, substantially lowered which is not continuous with respect to the side portions of the same bottom of the boat.
This central lowered portion of the hull provides the boat with a greater stability and a lower hydrodynamic impact, in comparison with other types of keels, for example with respect to keels with a continuous “V” bottom or similar.
The technique described above has some significant drawbacks.
In particular, despite the described improvements of the keels with a lowered central section, the boats continue to have a high hydrodynamic impact which translates into an increase in resistance to progress in the water, greater consumption and reduced comfort.
Furthermore, it would also be necessary to increase the horizontal stability of the hull itself during the movement of the boat.
In this situation, the technical task underlying this invention is to devise a hull for a nautical vehicle capable of substantially resolving the aforementioned drawbacks. As part of this technical task ,an important aim of the invention to achieve a hull of a vehicle that has a reduced hydrodynamic impact during the progress of the boat itself.
Another important purpose of the invention is to achieve a hull of a nautical vehicle that is very stable during its progress.
The technical task and the specified purposes are achieved by a hull of a nautical vehicle in which the vehicle defines a vertical direction coinciding, both in the use of the vehicle and when it is stationary, with the gravitational gradient, a longitudinal direction, coinciding with the direction of the progress (direction of travel) of the vehicle, and perpendicular to the vertical direction, and a transversal direction perpendicular to the longitudinal direction and to the vertical direction and in which the hull comprises, in particular, a central portion of the bottom of the hull arranged in the centre along the transversal direction, extending over a large part of the hull itself along the longitudinal direction, the side portions of the bottom, lateral to the central portion of the bottom in a transversal direction, in which the central portion of the bottom is also lowered substantially and discontinuously with respect to the side portions of the bottom of the hull, and in which the hull also includes central side walls designed to separate the central portion of the bottom from the side portions of the bottom, external side walls, external to the side portions of the bottom, in which the external walls have, in view of the lateral plane parallel to the longitudinal direction and vertical direction, a portion defining a first concave upwards curve mainly in the bow half of the hull, central side walls which, in view of the lateral plane and in intersection with the side portions of the bottom in the bow section, a section defining a second curve with upward concavity, placed further towards the bow with respect to the first curve, and in which the side portions of the bottom join the first curve and the second curve through a portion which is at least partially curved.
The characteristics and the advantages of the invention are clarified below by the detailed description of the preferred executions of the invention, with reference to the attached drawings, in which:
In this document, measurements, values, shapes and geometric references (such as perpendicularity and parallelism), when associated with words such as “roughly/about” or other similar terms such as “almost” or “substantially”, are to be understood, to a lesser extent, as measurement errors or inaccuracies due to production and/or manufacturing errors and, above all, as a slight divergence from the value, measurement, geometric shape or reference with which it is associated. For example, these terms, if associated with a value, ideally indicate a divergence of no more than 10% of the value.
Moreover, when used, terms such as “first”, “second”, “higher/upper”, “lower”, “primary” and “secondary” do not necessarily identify an order, a relationship priority or relative position, but can simply be used to more clearly distinguish between their different components.
With reference to the Figures, the hull of a nautical vehicle according to the invention is globally indicated by the number 1.
It constitutes part of a nautical vehicle 100 of any type, such as, in particular, a boat of any type such as a sailboat, a yacht, or a sportsboat such as a canoe, kayak or similar. Or a seaplane or similar.
In detail,
As previously mentioned, in this document the vertical direction 1c will mark the gravity direction when the vehicle is stationary on the water and when the water is calm or stationary. The longitudinal direction 1a, perpendicular to the vertical direction, marks the progress direction (direction of travel) of the nautical vehicle 100, usually coinciding with the direction of the prevailing extension of the vehicle 100 itself. The transverse direction 1b is perpendicular to the longitudinal direction la and vertical direction 1c. The horizontal plane is the plane perpendicular to the vertical direction on which the transverse and longitudinal directions lie.
It is also known that the hulls 1 have a bow point or bow, which is the most frontal or forward point, of the hull 1, along the longitudinal axis 1a, and a stern point or stern, which is the most rearward or rearmost point along the longitudinal axis la of the hull 1.
In addition, to define the positions along the longitudinal axis 1a, the hull 1 will be divided into sections, such as, for example, the half of the prow, which is the portion of the hull 1 which starts from the middle of the nautical vehicle, e.g., ship, and reaches the bow, the half of the stern, which is the portion of the ship which starts from the middle of the ship and reaches the stern, the first tenth from the bow, the second tenth from the bow, which are the portions which, dividing the nautical vehicle, e.g., ship, into ten portions, are the closest to the bow and including this and the portion immediately following. To facilitate understanding in
The hull 1 comprises a central portion of the bottom 2 of the hull which occupies, in the transverse direction 1b and in section or seen in the plane perpendicular to the longitudinal axis 1a, the central portion of the bottom of the hull 1. The central portion of bottom 2 extends over a large part of the hull 1. Ideally, the central portion of bottom 2 shall extend, in the longitudinal direction 1a from the bow up to and including the ninth tenth of the hull 1. The central portion of bottom 2 may also have an extension in the transversal direction 1b, so that in the frontal view (
The hull 1 further comprises side portions of the bottom 3, which are, in the transversal direction 1b and in section or view in the normal plan to the longitudinal axis 1a, lateral to the central portion of bottom 2. They shall ideally occupy the whole bottom of the hull 1, with the exception of the central portion of bottom 2.
The central section of bottom 2 is also lowered substantially and discontinuously with respect to the side portions of bottom 3. The phrase “substantially and discontinuously” is understood to be mean the difference between the average level or height, in the vertical direction, between the two central portions of the bottom 2 and the side portion of the bottom 3 visible and, for example, equal to at least one-tenth or better one-fifth of the width, in the transverse direction 1b, of the hull 1. Viewed from below, the central portion of bottom 2 has a tapered section at the ends and a maximum section at the centre which is ideally curved and continuous and essentially an ogival arch shape. Conveniently, near the centre in longitudinal direction 1a of the vehicle 100, the width in the transversal direction 1b of the central portion of bottom 2 shall be close to the width of each side portion of bottom 3.
The bottom of the hull 1 also has an essentially constant total width from the middle to the stern and tapers substantially towards the bow.
Also the height, in the vertical direction 1c, of the central portion of bottom 2 is preferably substantially constant and more preferably substantially concave towards the top.
The hull 1 also includes central side walls 4 designed to separate the central portion of bottom 2 from the side portions of bottom 3. These central side walls 4 are ideally parallel or slightly diverging, and preferably inclined, with respect to the vertical direction 1c, less than 30° and more preferably between 5° and 15°. The central side walls comprising opposed inner central side walls defining the central portion there between and opposed outer side walls, the central side walls comprising opposed outer central side walls. The opposed inner central side walls each having longitudinally front and back ends relative to the direction of advancement of the boat, wherein the front ends of the opposed inner central side walls meet, wherein the back ends of the opposed inner central side walls meet. The opposed outer central side walls each having longitudinally front and back ends relative to the direction of advancement of the boat, wherein the front ends of the opposed outer central side walls meet, wherein the back ends of the opposed outer central side walls meet.
The hull 1 also comprises external side walls 5 external to the side portions of bottom 3 and basically consisting of the side walls of the hull 1.
The outer walls 5 have, in view of the lateral plane parallel to the longitudinal direction 1a and vertical direction 1c, a portion defining a first curve 5a with predominantly upwards concavity, upwards and which is preferably essentially total, in the bow half of the hull 1.
Moreover, the central side walls 4 have, always in view of the said lateral plane and in the bow section, a portion defining a second curve 4a with upward concavity, placed more towards the bow than the first curve 5a and ideally with a minor average radius of lesser curvature. The average radius of the curve is evaluated because the two curves 4a and 5a may not be perfect circumference arcs and may therefore have a varying diameter.
Moreover, the side portions of bottom 3 shall join the first curve 5a and the second curve 4a through a portion that is at least partly curved. The said curve has a downward concavity and ideally a greater radius of curvature in proximity to the central portion of bottom 2.
Moreover, said second curve 4a preferably defines a portion of lower height, in the vertical direction 1c, with respect to the rest of the external side walls 5.
The stern portion, ideally at least the last 10th or the last fifth, of the side portions of bottom 3 is instead substantially flat and preferably slightly downwards inclined.
The bow is preferably higher than the other portions, as is usual.
The hull 1 furthermore ideally comprises the interceptors 6.
As is known, the interceptors are spoilers or flat portions extending substantially along the transversal plane and preferably mainly in the transversal direction 1b. They are designed to create depressions capable of reducing hydrodynamic friction.
The hull 1 shall include interceptors 6 arranged on the side portions of the bottom 3 at least in correspondence with the partially-curved portion joining the first curve 5a and the second curve 4a. They ideally occupy the outermost half of the side portions of the bottom 3.
The hull 1 also ideally comprises interceptors 6 arranged at the bow of the hull.
The hull 1 also includes air intakes 7 constituting the open channels, on one side, in line with the side portions of the bottom 3 and, on the other side, of a portion exposed to the air. When the boat is moving, the air that passes through the aforementioned channels arrives at the bottom of the boat due to the localised depression.
In this way, natural air lubrication is achieved by the generation of a dynamic air cushion also known as DYNAC or “Dynamic Natural Air-Cushion”.
These air intakes 7 should preferably have openings at the partially-curved portion joining the first curve 5a and the second curve 4a. Moreover, they are preferably placed closely and behind, preferably immediately behind, the interceptors 6 arranged on the lateral portions of the bottom 3 in line with the partially-curved portion which joins the first and second curves 5a and 4a. In addition, the air vents 7 in the vicinity of interceptors 6 preferably have the same width as interceptors 6, in the transversal direction 1b.
A further air vent 7 can be placed in the bow half of the hull 1 in line with the central portion of bottom 2.
Finally, the hull 1 includes foils 8. As is known, the foils are ailerons that extend mainly along the horizontal plane and are used mainly to increase the lift and stability of the hull 1.
The foils 8 are arranged at least in the central portion of the hull 1 and ideally also near the bow.
Finally, the boat may include spray rails, i.e. flat or wedge shaped portions in the normal section which extend mainly parallel to the longitudinal axis 1a and the vertical axis 1c and downwards and are arranged at the bottom of the side portions of bottom 3 and at the ends of the portions.
The hull 1 can also include side skirts 9, consisting of extensions towards the bottom of the hull sides. as visible in
The hull 1, as per the invention, achieves important advantages.
In fact, the front portion of the boat, including the aforementioned curves 4a and 5a and the side portions of bottom 3, create a depression in the stern half of the hull which considerably reduces the hydrodynamic friction. In addition, the side portions of base 3 create a depression in the bow half of the hull (allowing air blow-in) and greatly reduce the hydrodynamic friction. For example,
It is believed that the particular advantages are conferred by the described curvatures which create a depression in the bow half of the hull 1.
This hydrodynamic advantage is also increased, in particular with regard to the specific shape of the hull 1, by the interceptors 6 and the air vents 7. The interceptors 6 and the air intakes 7 act in synergy in the curved area, increasing the bearing capacity and stability of the boat.
Moreover, said foils 8 improve the stability of the hull 1; in particular they adapt to the described shape which confers stability in the areas of the foils 8.
The air vents 7 act in the depression zone following the curved area and increase the airflow.
These benefits also include a reduction of the bow wave.
In addition, the design of the hull 1 also achieves other important advantages.
For example, if applied to a motorboat, or a sailboat or a seaplane, of any size, the lowered portion allows one to accommodate the engine room of the boat and free up more space in the upper area.
Moreover, if used for military purposes, the aforementioned hull 1, thanks to its hydrodynamic shape, allows the boat to be immersed more deeply in the water and thus achieves a boat which is less visible on the water, while still maintaining a reduced hydrodynamic footprint, as illustrated in
Moreover, the combination of advantages inherent in the design allows for an increase in the habitability by 25% in comparison with the known designs of boats. The graph in
In
The invention is subject to variations falling within the scope of the inventive concept defined by the claims.
In this context all the details can be substituted by equivalent elements and the materials, the shapes and the dimensions can vary.
