Catamaran hull of hybrid structure and craft using such a hull

Abstract

A catamaran hull of hybrid structure includes a first lateral float, a second lateral float and a central float connecting the first lateral float to the second lateral float; the hull further including a first beam having a first bulkhead and a second beam having a second bulkhead, each bulkhead lying in a plane substantially perpendicular to the bow-stern line and including: a central part including a lower element intended to collaborate with a lower part of the central float; a first lateral part including a lower element intended to collaborate with a lower part of the first lateral float; a second lateral part including a lower element intended to collaborate with a lower part of the second lateral float; the hull part arranged between the first bulkhead and the second bulkhead defining a monobloc hull portion.

Claims

1. A catamaran hull of hybrid structure comprising: a first lateral float and a second lateral float; a central float joining the first lateral float to the second lateral float; a first beam consisting of a first bulkhead and a second beam consisting of a second bulkhead, each of the first and second bulkheads lying in a plane substantially perpendicular to a bow-stern axis and including: a central portion comprising a lower element configured to extend into and engage with a lower portion of the central float; a first lateral portion comprising a lower element configured to extend into and engage with a lower portion of the first lateral float; a second lateral portion comprising a lower element configured to extend into and engage with a lower portion of the second lateral float; the hull portion arranged between the first bulkhead and the second bulkhead defining a one-piece hull portion.

2. The catamaran hull according to claim 1, wherein the first bulkhead and/or the second bulkhead have an opening.

3. The catamaran hull according to claim 1, wherein the first bulkhead and/or the second bulkhead have a plurality of openings.

4. The catamaran hull according to claim 1, wherein the one-piece hull portion comprises a lower portion defining a hull bottom of the one-piece hull portion; said hull bottom being totally immersed when the catamaran hull is provided on a body of water.

5. The catamaran hull according to claim 1, wherein the one-piece hull portion comprises a lower portion defining a hull bottom of the one-piece hull portion; said hull bottom being partially immersed when the catamaran hull is provided on a body of water.

6. The catamaran hull according to claim 1, comprising a plurality of central floats, a plurality of first beams each first beam being constituted of a first bulkhead, a plurality of second beams each second beam being constituted of a second bulkhead, the central portion of each bulkhead comprising a lower element configured to extend into and engage with a lower portion of the central float of the plurality of central floats; each hull portion arranged between a first bulkhead and a second bulkhead defining a one-piece hull portion so as to form a plurality of one-piece hull portions.

7. The catamaran hull according to claim 1 further comprising a fourth beam arranged horizontally at the level of the rear portion of the hull so as to be positioned between the first lateral float and the second lateral float, said fourth beam including a first end joining the fourth beam to the first lateral float and a second end joining the fourth beam to the second lateral float.

8. A craft comprising a hull according to claim 1.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The figures are presented for indicative purposes and in no way limit the invention. They illustrate:

(2) FIG. 1A, a top sectional view of a hull according to a first embodiment;

(3) FIG. 1B, the structure of a beam according to one embodiment;

(4) FIG. 2, the structure of a beam having an opening according to one embodiment;

(5) FIG. 3, a top sectional view a hull according to a second embodiment;

(6) FIG. 4, a three dimensional representation of a hull according to a third embodiment;

(7) FIG. 5, a top sectional view of a hull according to a fourth embodiment.

DETAILED DESCRIPTION OF AT LEAST ONE EMBODIMENT OF THE INVENTION

(8) Unless stated otherwise, a same element appearing in the different figures has a single reference.

(9) According to a first embodiment illustrated in FIGS. 1A and 1B, the invention relates to a catamaran hull 5 of hybrid structure comprising a first lateral float D, a second lateral float G and a central float C joining the first lateral float D to the second lateral float G; the hull 5 further including a first beam consisting of a first bulkhead 1 and a second beam consisting of a second bulkhead 2 each bulkhead lying in a plane substantially perpendicular to the bow-stern axis PP and including: a central portion PC comprising a lower element PCI intended to cooperate with a lower portion of the central float C; a first lateral portion PD comprising a lower element PDI intended to cooperate with a lower portion of the first lateral float D; a second lateral portion PG comprising a lower element PGI intended to cooperate with a lower portion of the second lateral float G;
the hull portion arranged between the first bulkhead 1 and the second bulkhead 2 defining a one-piece hull portion 7.

(10) Thus, the first bulkhead 1 and the second bulkhead 2 make it possible to obtain a one-piece portion 7 of hull 5 which has a profile similar to a monohull. The hull 5 may be described as hybrid since the one-piece hull portion 7 of the hull 5 has a monohull profile whereas the hull portion or portions not comprised in the one-piece portion 7 have a catamaran profile.

(11) As illustrated in FIG. 1B, each bulkhead 1, 2 has a height H and a width L. The dimensions of the first bulkhead may be different from the dimensions of the second bulkhead. Alternatively, these dimensions may be identical. The first lateral portion has a width L.sub.G and a height H.sub.G, the central portion has a width L.sub.C and a height H.sub.C whereas the second lateral portion has a width L.sub.D and a height H.sub.D. The height of the bulkhead H is defined as equal to H=max(H.sub.C, H.sub.D, H.sub.G).

(12) In one embodiment, the first bulkhead 1 and the second bulkhead 2 are substantially rectangular. In other words, the surface of each bulkhead of width L and of height H is equal, to more or less 20%, to the surface of a rectangle of width L and of height H. The volume obtained between the first bulkhead 1 and the second bulkhead 2 then has a substantially parallelepiped shape which makes it possible to facilitate the internal layout of said volume.

(13) In one embodiment illustrated in FIG. 2, the first bulkhead 1 has an opening 4. This opening 4 enables external light to penetrate into at least one portion of the volume defined between the first bulkhead 1 and the second bulkhead 2. It also enables natural ventilation of this same volume.

(14) The stresses exerted on the bulkhead being mainly situated at the level of the upper and lower portions of the bulkhead, the layout of an opening 4 in the first bulkhead 1 only slightly reduces the mechanical strength of this first bulkhead 1. It is also possible to arrange a plurality of openings 4 on a same bulkhead. In the drawings, only the first bulkhead 1 has an opening 4. But it is possible to arrange an opening 4 or a plurality of openings 4 in the second bulkhead 2 or instead a first opening or a first plurality of openings in the first bulkhead 1 as well as a second opening or a second plurality of second openings in the second bulkhead 2.

(15) In one embodiment, the first bulkhead 1 and the second bulkhead 2 are positioned such that the one-piece hull portion 7 is situated at the front of the hull 5. In this embodiment, the hybrid catamaran hull 5 has a monohull profile at the front of the hull 5 and a catamaran profile at the rear of the hull 5.

(16) Alternatively, the first bulkhead 1 and the second bulkhead 2 are positioned such that the one-piece hull portion 7 is situated at the rear of the hull 5. In this embodiment, the hybrid catamaran hull 5 has a monohull profile at the rear of the hull 5 and a catamaran profile at the front of the hull 5.

(17) In one embodiment illustrated in FIG. 3, a third beam 3 mechanically strengthens the rear portion of the hull 5. Indeed, when it is wished to arrange the one-piece portion 7 of the hull 5 so as to obtain a large volume at the front of the hull 5, the first bulkhead 1 and the second bulkhead 2 are then both found arranged at the front of the hull 5. This can lead to a weakness at the level of the rear of the hull 5 in which no beam is present. The addition of a third beam 3 makes it possible to strengthen the rear of the hull 5 while conserving a hybrid structure, the hull portion 5 situated between the second bulkhead 2 and the third beam 3 having the profile of a catamaran hull. The third beam 3 thus has a similar shape to a beam employed in catamaran hulls according to the prior art.

(18) In one embodiment, a fourth beam 8 is arranged horizontally at the level of the rear portion of the hull 5 so as to be positioned between the first lateral float D and the second lateral float G, said fourth beam including a first end joining the fourth beam to the first lateral float D and a second end joining the fourth beam to the second lateral float G.

(19) In one embodiment, the fourth beam 8 is in the form of a central parallelepiped portion, a first end portion and a second end portion, said end portions forming an angle with the central piece, the central portion being situated in a plane parallel to the water plane. The central portion, the first end portion and the second end portion constituting a single mechanical piece. In this embodiment, the first end joining the first lateral float D is one end of the first end portion and the second end joining the second lateral float G is one end of the second end portion.

(20) In one embodiment, the distance separating the fourth beam 8 from the stern is less than or equal to 1 m. Preferably, the width of the beam 8 is comprised between 0.5 m and 2.5 m. In one embodiment, the distance separating the fourth beam from the water plane is comprised between 10 cm and 70 cm.

(21) In an alternative embodiment, a plurality of third beams 3 is provided. This plurality of third beams 3 strengthens the catamaran portion of the catamaran hull 5 of hybrid structure. This embodiment is particularly advantageous when the catamaran portion of the catamaran hull 5 of hybrid structure is too long for a single third beam 3 to suffice to make said catamaran portion rigid.

(22) In one embodiment, a third beam of the plurality of third beams 3 is arranged at the rear of the hull 5 so as to form the rear end of said hull 5, said third beam comprising a flattened upper portion forming a link between the first lateral float D and the second lateral float G. In other words, said third beam constitutes the stern plate of the first lateral float D and the second lateral float G so as to form a quarter deck over the whole width of the hull 5, at the level of said third beam. Such a quarter deck notably facilitates access to the sea or to land.

(23) In one embodiment illustrated in FIG. 4, in a similar manner to the embodiment of FIG. 3, a third beam 3 mechanically strengthens the rear portion of the hull 5. Moreover, the first bulkhead comprises an opening. In this embodiment, the first bulkhead is positioned at 90% of the length of the hull; the second bulkhead is positioned at 75% of the length of the hull. The third beam is positioned at 40% of the length of the hull so as to strengthen the rear portion of the hull.

(24) First bulkhead positioned at 90% of the length of the hull is taken to mean that a distance equal to 90% of the total length of the hull separates the rear of the hull from the position of the first bulkhead. Similarly, second bulkhead positioned at 75% of the length of the hull is taken to mean that a distance equal to 75% of the total length of the hull separates the rear of the hull from the position of the second bulkhead. Similarly, third beam positioned at 40% of the length of the hull is taken to mean that a distance equal to 40% of the total length of the hull separates the rear of the hull from the position of the third beam.

(25) As mentioned previously, the hull 5 may comprise a plurality of central floats, a plurality of first beams each first beam being constituted of a first bulkhead, a plurality of second beams each second beam being constituted of a second bulkhead, the central portion of each bulkhead comprising a lower element intended to cooperate with a lower portion of the central float of the plurality of central floats; each hull portion arranged between a first bulkhead and a second bulkhead defining a one-piece hull portion so as to form a plurality of one-piece hull portions. In this configuration, it is thus possible to provide a plurality of volumes of monohull type within the hull 5.

(26) In one embodiment illustrated in FIG. 5, two one-piece hull portions 7, 7 are provided. To do so, in this embodiment, the hull comprises a first central float C, a second central float C, a first bulkhead 1, a second bulkhead 2, a third bulkhead 1 and a fourth bulkhead 2; each one-piece hull portion 7, 7 being arranged between a first bulkhead 1, 1 and a second bulkhead 2, 2. The first lateral float D and the second lateral float G are thus joined by means of a first central float C and a second central float C.

(27) More specifically, the lower element of the central portion PC of the first bulkhead 1 and the second bulkhead 2 cooperates with a lower portion of the first central float 7. The lower element of the first lateral portion of the first bulkhead 1 and the second bulkhead 2 cooperates with a lower portion of the first lateral float D. The lower element of the second lateral portion PG of the first bulkhead 1 and the second bulkhead 2 cooperates with a lower portion of the second lateral float G. Similarly, the lower element of the central portion PC of the third bulkhead 1 and the fourth bulkhead 2 cooperates with a lower portion of the second central float 7. The lower element of the first lateral portion of the third bulkhead 1 and the fourth bulkhead 2 cooperates with a lower portion of the first lateral float D. The lower element of the second lateral portion PG of the third bulkhead 1 and the fourth bulkhead 2 cooperates with a lower portion of the second lateral float G.

(28) Thus, the hull portion arranged between the first bulkhead 1 and the second bulkhead 2 defines a first one-piece hull portion 7 whereas the hull portion arranged between the third bulkhead 1 and the fourth bulkhead 2 defines a second one-piece hull portion 7.