Abstract:
A multichambered boat that is constructed upside-down on stationary platforms where flotation chambers are located in the perimeter portion of the multichambered boat. The perimeter chambers have a laterally downward sloping exterior surface that directs fluid downwardly and provides lift to the multichambered boat which creates a smoother ride. A fuel input line that passes through the flotation chamber to the fuel storage tank to provide convenient access for refueling the multichambered boat.

Description:
RELATED APPLICATIONS 
     This application is a Continuation Patent Application of U.S. patent application Ser. No. 10/350,843 filed Jan. 24, 2003, now abandoned which is a Continuation Patent Application of U.S. patent application Ser. No. 09/642,113 filed Aug. 18, 2000 now U.S. Pat. No. 6,520,107; which in turn is based on 60/149,957 filed Aug. 19, 1999. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to chambered water vessels and the location and design of chamber walls, and other design features. Further, the invention relates to a method of manufacture to produce the water vessels. 
     BACKGROUND 
     It is desirable to have watercrafts to remain afloat even when the open hull becomes filled of water. To make this possible discrete floatation chambers have been employed in watercraft for many years. Thus, in the event that the seal of one chamber is compromised and the buoyant effect of that chamber is lost, the other chambers will still have a buoyant effect so that the watercraft will remain afloat. 
     Due to the safety problems of punctured chambers the U.S. Coast Guard has implemented rigorous standards with which the boats under their jurisdiction must comply. One such regulation is the mandatory use of foam in the chambers to reduce the amount of water the chamber would take on in the event the chamber wall is punctured. There are many problems with foam injected chambers. First, it is very costly to inject foam into the chamber; the foam must be distributed evenly and the injection equipment is expensive to purchase and maintain. Secondly, If the foam filled chamber is punctured, repair of the chamber is difficult to impossible. It is somewhat difficult to remove the water that is soaked into the foam. Further, the aluminum wall that defines the chamber must be welded to recreate a sealed chamber and the heat from the welding process will melt the foam, creating noxious gas and leaving a portion of combusted foam no longer of use for floatation. 
     Another aspect of the design and manufacture of floatation boats is the construction of chambers has traditionally been accomplished by rolling sheets of aluminum to form a curved wall to define the chambers. There are numerous problems with the rolling process that results in variations in the shape and dimensions in the chamber walls. This lack of consistency makes the use of efficient manufacturing techniques difficult or in some instances impossible. 
     Another method of creating chamber walls is to extrude the aluminum through a mold to a preferred shape. This process is very expensive and can weaken the metal. 
     Yet another aspect related to the larger boats which generally have an internal combustion engine to power the prop, the fuel tank must reside in a safe place while still having a convenient access to the tank. The inlet port to refuel the tank has traditionally been in the back of the water vessels near the engine. Often times when a boat is in the water, the rear of a boat is lower than the front, because there is generally more load to the rear of the center of buoyancy of the water vessel. This position of the boat causes the gas to shift to the rear of the tank, which increases the hydrostatic pressure for a refueling inlet port located in the rear of the boat. This increase in pressure makes refueling more difficult 
     SUMMARY OF THE INVENTION 
     The invention is a multichambered boat having a central lower portion and a lateral portion where the central portion slopes upwardly from the laterally inwardly portion to the laterally outworked portion where it engages a perimeter contact surface that slopes laterally downwardly. The perimeter contact surface is part of a flotation chamber. The flotation chambers are located in the perimeter portion of the boat and provide buoyant lift. A fuel input line having an intake nozzle located in the upper portion of the flotation chamber and a central line extending through the chamber to an outtake nozzle located in the laterally inwardly portion of the chamber. The outtake nozzle is connected to a flexible close that is in communication to the fuel storage tank. 
     The multichambered boat hull is manufactured by utilizing stationery platforms having placement holders that are adapted to hold multi-creased wall sections that eventually form floatation chambers. Baffles are placed in between two adjacent multi-creased wall sections and are welded thereto to form discrete chambers. 
     One aspect of the invention is a strategic and precise placement of the chambers to minimize cost of construction and maintain a high level of safety in the event several chambers are punctured. The invention removes the need for costly foam injection chambers by placing the chambers at locations to reduce the risks in circumstances where multiple chambers are punctured. 
     Another aspect of the present invention is that each of the chambers are defined by a multi-creased wall that comprises a plurality of longitudinal creases or bends. The construction of the wall is accomplished by taking a flat piece of metal, preferably aluminum, and bend it about a longitudinal straight edge. This process is continued until the wall loops around to create a continuous tube like configuration, where the chamber has in cross sectional configuration the shape of an irregular polygon. This multi-creased wall is configured in a way so that it has an increased moment of inertia about the transverse axis, thus creating a stronger vessel. A majority of the bending moments on a water vessel are about the transverse axis, therefor increasing the moment of inertia about the transverse centroidal axis reduces the stresses experienced on the multi-creased walls and the water vessel as a whole. 
     After the multi-creased sections are formed they are assembled together in a rigid platform assembly to create very consistent dimensions of the final boats produced. 
     A further advantage of the preferred embodiment is a oblique surface in the lower portion of the multi-creased wall which has particular fluid flow advantageous by directing up-skirting water along the v-shaped hull in a downward direction, thus creating lift and a smoother ride for the passengers. This is beneficial in rough waters where the boat is impacting waves. The oblique surface can also assist in cornering as well. This oblique surface has the additional advantages of reducing the spray that is created when the water flows around the V-shaped wall in the lower hull. 
     The result is a light, safe high performance water vessel that is less expensive to manufacture. 
     BACKGROUND ART 
     A search of the patent literature has a number of patents directed toward creating flotation chambers. U.S. Pat. No. 4,667,618 Cigognetti, shows a means to form a water tight space between keel and deck elements in an inflatable boat. The keel section  2 , and the deck section  1 , are joined at the edges to tubes  5 , and  6 . Tubes  5 , and  6 , may be either the floats, or float housings. 
     The following patents show various boat configurations in which there are water tight compartments along at least part of the sides, and which are joined to form a hull. 
     U.S. Pat. No. 5,699,749 Yamada, shows a personal watercraft in which the hull is provided with a sponson  73 , seen best in  FIGS. 1 ,  7 ,  8 , and  9 . The assembly appears to be bolted to the remaining parts of the hull. 
     U.S. Pat. No. 5,546,886 Franceschelli et al, shows a boat built upon hull “T”, and deck “C”. There are compartments  3 , formed in tubular enclosures along each side. 
     U.S. Pat. No. 5,261,345 Fleming, shows a boat in which inflatable air bladders  2 , may be joined to rigid bottom  4  shown in  FIG. 2 . 
     U.S. Pat. No. 5,184,566 Cochran, shows a girder type hull to which flotation element  80  is secured. 
     U.S. Pat. No. 5,078,072 Horiuchi et al, shows a boat formed with a pair of outer sponsons  13 , which appear to form water tight portions and hull elements  12 . 
     U.S. Pat. No. 4,781,136 Van Der Velden, shows a cockpit suspended between a pair of water tight sponsons. 
     U.S. Pat. No. 4,627,372 Douglas, shows a catamaran in which the hull section are formed of sections  11  that are provided on the ends with pointed or streamlined elements  12 . The sections  11  are rectangular and mounted so that an edge is at the lowest point so that it forms a keel like configuration. 
     U.S. Pat. No. 4,348,972 Parsons, shows a three hulled boat in which there is a central hull  12 , and a pair of side hulls  32  and  34  which are joined by a deck which is above the waterline. 
     U.S. Pat. No. 4,192,248 Moyer, shows a hull that is formed from two elements that are joined in the center. 
     U.S. Pat. No. 4,046,092 Tornqvist, shows a cargo ship hull in which the sides and the bottom of the top deck are joined where the upper wingward spaces  9 ′ and  9 ″, are provided that house pipelines, conveyors, or the like. 
     U.S. Pat. No. 3,470,839 Faul et al, shows a boat in which there are hull structures on each side and a central bottom portion that is partially in the water. 
     U.S. Pat. No. 3,140,686 Olivotti, provides a boat with side stabilizing elements “ST”, that extend from the side above the level of the water. 
     U.S. Pat. No. 2,560,153 Blount, shows a boat that is formed of two parallel cylinders that are joined by bulkhead elements  20 . Plates  24  and  25  are secured to the cylinders to form the bottom and the deck of the ship. The ends of the cylinders are shaped to form bow and stern configurations. 
     U.S. Pat. No. 1,303,690 Leparmentier, shows a barge that is formed of two cylindrical floats that are joined by plates a, b, and c. The space between “b”, and “c”, may be used for liquid cargo or ballast, and the section between “a”, and “c”, may be Used for storage or equipment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of a the preferred embodiment of a hull configuration; 
         FIG. 2  is a side view of the hull configuration; 
         FIG. 3  is a cross sectional view of a the hull side section taken at line  3 — 3  in  FIG. 1 ; 
         FIG. 4  is a cross sectional view of a baffle taken at line  4 — 4  in  FIG. 1 ; 
         FIG. 5  is a cross sectional view of a multi-creased chamber wall taken at line  5 — 5  in  FIG. 1 ; 
         FIG. 6  is a cross sectional view of a fuel insert system taken at line  6 — 6  in  FIG. 1 ; 
         FIG. 7  is a vector diagram of the mean fluid velocities of up skirting water. 
         FIG. 8  is a vector diagram of the vertical and horizontal components of the resultant velocity vector derived from  FIG. 7 . 
         FIG. 9  is a perspective view of a method of manufacture of the aluminum chambered boat hull. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Throughout this description reference is made to top and bottom, front and rear. The device of the present invention can, and will in practice, be in numerous positions and orientations. These orientation terms, such as top and bottom, are obviously used for aiding the description and are not meant to limit the invention to any specific orientation. 
     As seen in  FIG. 1 , the chambered boat hull  20  comprises a V-shaped bottom wall  22 , a bow  24 , a stern  26 , a rear plate  27 , a perimeter hull portion  28  and a central hull portion  29 . The chambered boat hull  20  has a longitudinal axis  21  that runs from the bow  24  to the stern  26  and is symmetrically positioned in the center portion of the chambered boat hull  20  as shown in  FIG. 1 . The chambered boat hull  20  further has a vertical axis running from the upper portion to the lower portion of the chambered hull and a transverse axis running from the center of the chambered hull and extending outwardly in a level plane and perpendicular to the longitudinal axis. The central hull portion is contracted so that a cab or other structure can be mounted thereon. 
     The perimeter hull portion  28  comprises a plurality of multi-creased wall sections  30  that are best seen in  FIG. 5 . Each of these wall sections have a plurality of creases  32 . The wall sections  30  are constructed by taking a flat piece of metal and making several sharp bends at designated locations  32 . The end locations  33   a  and  33   b  of the multi-creased wall section  30  over lapped and are welded together to create a seal. The angles of the bends at creases  35  are as follows: 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 35a 
                 33° 
               
               
                   
                 35b 
                 30° 
               
               
                   
                 35c 
                 28° 
               
               
                   
                 35d 
                 20° 
               
               
                   
                 35e 
                 85° 
               
               
                   
                 35f 
                 26° 
               
               
                   
                 35g 
                 61° 
               
               
                   
                 35h 
                 −85°   
               
               
                   
                 35i 
                 86° 
               
               
                   
                 35j 
                 70° 
               
               
                   
                   
               
             
          
         
       
     
     Each angle can vary to some degree, and further, more creases can be added without departing from the spirit of the invention. 
     The angle of surface  52  ( 35   j ) with respect to the vertical axis has a most desirable range between 80° and 87°, and a secondary desirable range between 75° and 90°. The angle of exterior surface  48  of the V-shaped bottom wall  22  has a most desirable range between 15° and 22°, and a secondary desirable range between 10° and 26°. 
     Between each multi-creased wall section  30 , there is a baffle  34 , which is positioned at the locations indicated at  36 ,  38  and  40 . As seen in  FIG. 4 , the baffle  34  is connected to multi-creased walls  30   a  and  30   b . Each pair of proximate baffles  34  in combination with a multi-creased wall sections  30  defines a chamber  42 . The chambers  42  are sealed so no water can penetrate therein. The chambers are also pressurized to a 5–16 p.s.i. The internal pressure helps maintain the shape of the multi-creased walls  30  and help prevent the walls from buckling inwardly when the chambers  42  are submerged. 
     Now referring back to  FIGS. 1 and 2 , in the preferred embodiment the perimeter hull portion  28  comprises 7 discrete chambers. Each chamber is sealed and can provide a buoyant force of hundreds of pounds when they are submerged in water. 
     Along the outer edge is a multi-creased wall sections  30   a  is a perimeter rim  44  which has an outer contact surface  46  that is adapted to come in contact with obstacles such as docks and other boats before coming in contact with the multi-creased walls  30 . 
     The V-shaped bottom wall  22  is located in the lower central hull portion of the chamber hull  20 . The V-shaped bottom wall  22  has an exterior surface  48  that is in contact with the water. The V-shaped bottom wall  22  is welded to the multi-creased wall  30  at point  50 . Surface  52  is positioned between point  50  and crease  32   a . As water flows along exterior surface  48  in an upward direction, the water will come in contact with surface  52  which directs the water in a downward direction. The momentum change of the flowing water creates a lift upon the chambered boat hull  20  that results in a smoother ride. The angle between the contact surface  52  and V-shaped bottom wall  22  is approximately 152°. Assuming the water flowing parallel to the V-shaped bottom wall, the water is redirected 38°. The V-shaped bottom wall is approximately 18° from the horizontal plane and the surface  52  is approximately 20° from the horizontal plane. The lift resulting from the flowing water is governed by the momentum equation: F=m* Δv/Δt; where F=Force, m=mass and Δv/Δt=change of velocity with respects to time. In a fluid flow problem such as this the force exerted from changing the direction of a fluid flow is a function of the density of water ρ, times the Volumetric flow rate of the water V, times the velocity change of the water Δv; which is F r =ρ∘V∘Δν. To graphically represent the forces acting upon the chambered hull  20 , the vector  76  represents the velocity vector of the mean flow of water traveling up the V-shaped lower wall  22 . Likewise the vector  78  represents the mean flow of water off of the surface  50 . The vector  78  may be slightly shorter than vector  78  because there are slight losses in the change of direction of the water flow.  FIG. 7  shows a resultant vector  80 , which is derived from subtracting vector  76  from vector  78 . As seen in  FIG. 8 , this resultant vector  80  comprises a vertical component  80   b  and a horizontal component  80   a . The vertical component  80   b  is the net change in velocity of the water flow that can be used to calculate the vertical force exerted upon the chambered hull  20 ; this resultant force being F r =ρ∘V∘(value of vertical component  80   b ). Other angles could be used for the surface  52  and V-shaped wall  22 ; however, the angles in the preferred embodiment are particularly advantageous for a desirable fluid flow that has an average resultant force F r  that provides a substantially smoother ride. 
     A fuel intake system  54  is shown in  FIG. 6 . The internal passage  56  comprises an intake  58 , a central portion  60  and an outlet  62 . The intake  58  is housed around the upper sheath  64 . The central portion  60  passes through the chamber  42 . The outlet  62  is surrounded by lower sheath  66 . The upper sheath  64  is welded to the multi-creased chamber wall  30  and the intake  58  is in tight communication to the upper sheath  64 . The lower sheath  66  is welded to the multi-creased wall  30  and the outlet  62  is sealed to the lower sheath  66  which seals the chamber  42  so it can withstand a pressure differential between the inside and outside of the chamber  42 . 
     A flexible hose  68  is connected to the outlet  62  and extends to fuel inlet  70  which is connected to fuel tank  72  which is supported above the V-shaped bottom wall  22  by tank supports  74 . The location of the fuel tank  72  can be anywhere in the central portion of the hull. Using the flexible hose  68  allows the tank to be positioned in the rear of the boat because generally the fuel tank is in the stern location of the boat. 
     It is desirable to place the fuel intake system  54  in the central to front portion of the chambered boat hull  20 . This provides convenient refueling especially when the boat is loaded in the aft portion of the chambered boat haul  20  and the fuel in the fuel tank  72  builds hydrostatic pressure in the aft portion of the fuel tank because it is positioned lower than the forward portion of the tank allowing fuel to occupy the upper aft portion of the tank  72 . 
       FIG. 9  shows a method of manufacturing the chambered boat hull  20 . The assembly  82  comprises a plurality of stationary platforms  84 . Located on each platform are placement holders  86 . In a manufacturing operation the multi-creased wall sections  30  are placed on the stationary platforms  84  at a location in-between the placement holders  86 . A baffle  34  is placed between each multi-creased wall sections  30 . The baffle and two adjacent multi-creased wall sections  30  are welded together. This operation creates very consistent dimensions of the boats. 
     Thereafter the V-shaped bottom wall  22  is welded to the perimeter chamber assembly  37  (see  FIG. 1 ) and the rest of the construction of the boat can take place thereafter. 
     While the invention is susceptible of various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and described in detail. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed, but, on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention. Specific embodiments have been shown by way of example in the drawings are described in detail. Its should be understood, however, that it is not intended to limit the invention to the particular forms disclosed, but, on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as expressed in the appended claims.