FR2579164A1 - Multi-hull boat structure allowing them greater safety on the open sea - Google Patents

Abstract

The subject of the present invention is the creation of a multi-hull ship structure called a catamaran, homogeneous yet composite, rigid yet flexible and capable of being dismantled; furthermore, insubmersible and self-righting in the event of capsizing. The structure consists of composite modules 1-5, 24 articulated together by flexible links which may be fixed or capable of being dismantled. This device allows the rigidity of the boat to be increased while damping the dislocation stresses, the impacts and vibrations due to the wind and to the sea. The wind resistance of the superstructures is reduced, and thus the risk of capsizing. Moreover, since the two floats are transformed into "water ballast", the structure allows, if necessary, by virtue of a self-inflating device placed at the head of an articulated, two-legged spar 24 and, with the aid of the latter, rapidly uprighting the boat in the event of overturning while remaining dry and under shelter.

Description

The structures usually encountered with catamarans in the prior art are of two kinds:
A) - Catamarans with Bras de Liaisons (CBL)
Figure 1 illustrates a CBL in a cross section with its connecting arm connecting the two shells.

 Figure 2 shows the same boat seen in profile.

 Figure 3 the same seen from above.

 The benefits of this formula are clear. Regardless of the lightness, therefore the speed -This structure offers little wind resistance (it is not dunnage but the action of the wind tending to rush under the superstructures exposed by the action of the waves to make sancier (figure 7) or capsize (figure 8r the boat.

-This structure can theoretically be composite and modular allowing transport.

Disadvantages: -These boats are only suitable for racing indeed (see Figures 1 -2 -3) only the hulls are habitable offering noticeable discomfort.

 The relatively thin link arms introduce a significant phase difference between the vibrations of one shell compared to the other, this regime of vibrations not damped in the current state of the art, to which the inherent effects of dislocation are added. hulls, held only laterally, will eventually tire connections which can break, causing the loss of the boat.

-In fact, except for skiffs / the composite structuring of large catamarans for the reasons we have just expressed is a myth. These boats will always be built in one piece for reasons of homogeneity of structure and material and therefore never dismantled. Road transport except for small units is therefore impossible.

-These boats, if they are easily made unsinkable, once capsized on the high seas, are lost because they are not self-righting.

B) - Central Platform Catamarans (CPC)
The CBL being uninhabitable, it was necessary by extending the external and internal plating of each hull horizontally to create a central platform (fig. 4,5,6)
The advantages are also obvious: - The habitability is exceptional, the whole platform can be converted, the two hulls serve as a corridor in general.

-The structure is perfectly rigid because it is homogeneous and thick which can be compared to that of a monohull ship (compare fig. 1 and fig. 4) -there is no suffering from the connections because no relative movements of a shell relative to the other, nor vibration.

 The Disadvantages: -The boats obtained are heavier therefore slower.

-The central platform offers a wind resistance equivalent to a good size sail when under the effect of waves the boat exposes this superstructure to the wind it is easily capsized. (see fig. 7 and 8) - Capsized boats are rarely unsinkable so as not to obstruct the interior space. In addition to interesting and vague theoretical proposals to make them self-righting / in practice none of the C.P.C. who sail are not because none were built to be and if they came to ltêtrezil would lose their primordial quality: the habitability I - These boats are of course unassemblable and non-transportable except those of small size.

 We have found and this is what is the subject of the present invention, an original structural device having the advantages of C.P.C. and C.B.L and eliminating the respective drawbacks.

-The said structure can also be removable -The diteastructure according to the invention can also be unsinkable without obstructing the interior space.

-The so-called structure making this ship possibly self-righting to radically alleviate the tragic consequences of capsizing on the high seas.

The crew will straighten the boat dry and safe.

 The structural device according to the invention is composed of seven modules involved in a preferred embodiment.

List of modules
Module NO 1 = Hull or port float (1)
Module NO 2 = Hull or starboard float (2)
Module NO 3 = Front link triangle (3)
Module NO 4 = Platform (4)
Module NO 5 = Rear link triangle (5)
Module NO 6 = Rear link arm (10)
Module N0 7 = Bipod spar (24)
The hulls in a preferred embodiment are called "floats" because they are uninhabitable and of purely technical use.

General description of a preferred implementation:
The invention of two floats or hulls: modules 1 (1) and 2 (2), of an unprecedented form1 made it possible to pass on the respective forces generated by the sea (floats) and the wind (rigging) by triangulation of the forces using modules 3 (3) and 5 (5) at the level of a torsion damper, the nacelle or module 4 (4). This module 4 (4) being connected in a particular way (22) (23) (25) (26) to the floats which allows the structure to react in a completely homogeneous way to the elements.

 It is planned as part of a preferred embodiment to use in (13) (14) (15) (16) (17) (18) (6) (7) (20) (21) (22) (23 ) (25) (26) flexible and dismountable connections, which makes it possible to produce composite modules, that is to say in different materials according to the service required for each module: thus the hulls can be made of aluminum, the laminated nacelle .

 Technical characteristics of modules 1 (1) and 2 (2).

 These modules are hulls or floats which can benefit from all the architectural techniques existing in terms of dead or living works.

 However, and this is the object of the present invention, the very shape of the floats or hulls is modified in an original manner by extending the rear or the transom of the said hulls upwards, according to a variable angle of incidence more or less close to the vertical, over a distance which can for example range from the fifteenth to a third of the length of the said shells to constitute an aerial appendage (11) (12) of variable dimension in width and thickness, monobloc, composite, perforated or even tubular serving as a strut or flying buttress.

 FIG. 9 illustrates the starboard strut (11) of module 2 (2) according to the invention.

Role of the struts (11) (12)
These legs have the role of raising the structure rearward on the longitudinal plane giving on a side view a thick profile comparable to that of the CPCs of FIG. 5 and even more effective.

 These struts will be able to admit either of flexible or rigid connections or directly by bonding welding stratification of the connection arms in any material (shown in dotted lines in FIG. 9).

These link arms (27) can, as indicated in FIG. 10 which constitutes a variant, come directly from the front end of the opposite float by following a diagonal trajectory crossing towards their middle in X with the contralateral link arm.

Figure 10 illustrates the path of the arms on this variant with the front transverse arm (8) the upper rear transverse arm (9) joining the tops of the two struts (11) (12).

The lower rear transverse arm (10) is common with the embodiment below.

According to a preferred embodiment modules 1 (1) and 2 (2) are maintained respectively in (13) (14) by module 3 (3) in (15) and (16) by module 5 (5), in ( 76) and (18) by the module 6 (10) and also maintained doubly on each rib in (22) (23) and (25) (26) by the nacelle or module 4 (4).

FIG. 11 illustrates the overall structure device seen from above.

FIG. 12 illustrates the overall structural device seen from the side with the module 1 (1) in the foreground.

it is advisable for the continuation of the technical explanations to refer unceasingly to these two figures.

Characteristics of modules 3 (3) and 5 (5)
These link arms according to the preferred project form two distinct modules which can be easily separated by disassembly, of roughly triangular isosceles shape, symmetrical with respect to one another, fixed to the nacelle (4) by their possibly truncated vertices respectively (6 ) and (7) the bases (8) and (9) connecting respectively by the connections (13) and (14) the fronts of the floats (1) and (2) and by the connections (15) and (17) the vertices rear struts (11) and (12).

 These link arms will be built possibly waterproof and will serve as a buoyancy reserve to make the unsinkable boat floating flush with the water, only a small part of the nacelle, also possibly waterproof, will be in contact with water, the crew being dry in the said nacelle (4).

They also have a function of distributing the efforts of the hulls and the rigging to transmit them to the nacelle (4).

 Characteristics of module 4 (4) or nacelle.

 it is technically a shock absorber or torsion box of roughly parallelepiped shape in the preferential project or any other form. it is possible to install facilities for the cruise.

This Module (4) is integral by any linking process (6) (7) in this example of modules 3 (3) and 5 (5) and by (22) (23) and (25) (26) of module 1 (1) and module 2 (2).

In the preferred embodiment we see a tubular structure forward (6) aft (7) strongly shouldered inside the nacelle and continuing for (6) by extensions respectively port (21) and starboard (20) which will support the articulated base of the bipod or module 7 spar (24) held by the front stay and the backstays.

 Function of the nacelle - Damping the forces of the hulls and the rigging and distributing them homogeneously throughout the structure = role of shock absorber - torsion boot.

-Flexibly resist its volume and its elasticity to the compression forces of the bipod spar under the effect of the airfoil.

-By its particular shape on the front it will help to straighten the boat with modules 1 (1) and 2 (2) being filled with water.

 -Keep the crew safe and dry whatever the damage and even in the event of capsize thanks to the buoyancy of modules 3 (3) and 5 (5) and 7 (24). it is easy to see in figure 13 that the nacelle rests out of the water in any position of the boat, place, upside down, vertical.

-The gondola is also the living space on board, it houses very comfortable facilities.

Technical characteristics of module 6 (10)
The module 6 (in) is a simple waterproof and unsinkable rear link arm connecting transversely by the links (16) (18) to the rear of the two floats at the level of the installation of the struts on the floats.

 Function: stiffen the structure.

Technical characteristics of module 7 (24)
This module can be in a variant replaced by a simple mat.

it is a bipod spar (24) solidly structured, this spar rests by its bipod base on the tubular structure (6) of the nacelle (4) in (20) and (21), it can be in one embodiment preferential articulated in (20) (21) to pivot easily forward.

 Function: -This spar supports the props where your sails are rigged -This spar has a waterproof and unsinkable structure, it therefore has a positive lift which contributes greatly to the safety of the boat in the event of overturning see figure 13.

-It can carry a self-inflating balloon at the head which can further increase this lift on demand to straighten the boat after the floats (1) and (2) have been filled with water.

 -it is tiltable forward thanks to its base articulated in (20) and (21) to the tubular structure (6) of the antero-superior part of the nacelle (4) (this in the context of a preferred embodiment ) -it can also be fixed and placed elsewhere or otherwise.

If it is mobile after capsizing go, the backstays being deposited as well as the shrouds if necessary, the forestay before returning to the nacelle (4) by a pulley located in the middle of the arm (8) and winched on a capstan, l 'espar will take a strong quest on the front lean on the water thanks to its inflated balloon, (the floats (1) and (2) previously filled with water the catamaran being vertical as shown on Figure 14). The ever-increasing spar will act as a lever to complete the recovery of the catamaran (Figure 15).

it will not remain any more as it is shown on figure 16 that to empty the floats (1) and (2) of their water, to raise the mat by winching the backstay on a capstan with 'a matereau.

 Technical characteristics of the links.

 it is planned to use in (6) (7) (20) (21) (15) (16) (17) (18) (14) (13) (22) (23) (25) (26) flexible connections with clearance control and which can be dismantled as part of a preferential device (joints + vibration damper axes) because these connections absorb vibrations and do not transmit them to the structure. A variant can be designed using any other type of link.

Description of the method for straightening a catamaran
of the type described in the preferential project after capsizing.

 The catamaran rests upside down as shown in Figure 13, the hulls are extended backwards and upwards the modules (3) (4) (5) are in contact with water, a small part of the nacelle (4) between the modules (3) and (5) is submerged, this part can be constructed waterproof.

The crew let the hulls fill with water, for this purpose we see a protuberance on the front of the hull where there is an intake valve comprising a inertia valve (not illustrated) there is a valve for the air exhaust.

As the floats (1) and (2) fill with water, the catamaran stands upright aft towards the sky (see figure 14).

At this stage it is quite possible that the oblique shape of the front of the nacelle with the help of the liquid hull appearing in the said floats, aided also by the strong lift of the bipod spar (24) is enough to straighten the boat.

If this were insufficient, the inflation of the mast head balloon would be activated from the nacelle to further increase this lift (Figure 15).

If that were still insufficient we would remove the backstays and we would maneuver as it says the bipod spar (24) by giving it a quest on the front, the boat upright, we would empty the floats by means of a pump located in the nacelle, the strainer of which appears at the bottom of the floats, the spar regressed, the boat is ready to set sail again (figure 16) it is remarkable that thanks to this structure device the crew does not leave the nacelle at any time to carry out these maneuvers, it therefore remains constantly safe or even dry.

The abandonment of the boat is no longer necessary even in the event of damage to the spar (24) the crew could advantageously remain on board while waiting for help rather than entrusting their life to some weak and risky skiff.

Claims (9)

 1) Structure for multihull ship (catamaran) characterized in that the port or starboard hulls or floats (1) and (2) have their rear or their transom extended upwards at a variable angle of incidence (for example that of backstays) to form an aerial appendage (11) (12) of variable size in width and thickness, monobloc, composite, perforated or tubular, natural extension of the hull upwards or added, serving as a strut whose role is , using link arms attached to its top to give better longitudinal rigidity to the boat and to keep the nacelle (4) out of the water after capsizing.  2) structure according to claim 1, characterized in that the shells (1) (2) are interconnected by connecting arms (8) (9) (10) transverse and two diagonally crossing arms (27).  3) Structure according to claim 1, characterized in that the shells (1) (2) are connected by two modules (3), (5) of roughly triangular shape whose bases (8) (9) respectively bring together the two fronts and the top of the two rear struts (1I) (12) the backs of (1) and (2) being joined by a simple transverse link arm (10).  4) Structure according to claims 1 and 3 characterized in that a nacelle or module (4) is interposed between (3) and (5) and connected to (1) and (2)  5) Structure according to claims 1,2,3, and 4 characterized in that a possibly bipod spar (24) comes to rest or articulate on (3) or (4) to support the rigging and / or help the righting the boat.  6) Structure according to claims 1,3 and 4 characterized in that the nacelle (4) has its front part inclined rearward and downward to give by this single form an attitude already practically normal to the boat with the floats of water to straighten it after capsizing.  7) Structure according to claims 1,3,4 and 5 characterized in that the hulls (1) (2) are floats which can be completely filled with water in the event of the boat capsizing so that this liquid ballast allows the crew to straighten said boat, this water then being discharged. The triangular modules (3) and (5) are then waterproof, unsinkable and their volumes calculated so that added to the lift of the nacelle (4) out of the water.  8) Structure according to claims 1,3,4,5 and 6 characterized in that a self-inflating balloon placed at the head of the bipod spar (24) authorizes the recovery of the capsized boat thanks to the quest on the front given to this spar whose bases are articulated.  9) Structure according to one of claims 1 to 8 characterized in that the composite modules are connected together by removable joints mounted on elastic seals, constituting vibration dampers ensuring both rigidity, homogeneity and flexibility of the structure, due to the particular shape of the rear of the shells as described above.