Abstract:
A multi-hull design for a large apparatus and a propulsion system for same. The apparatus is a triangular boat hull apparatus having a bow and stem wave penetrating feature. The hull is composed of one triangle overlapping two additional triangles on the port and starboard sides of the apparatus. This invention includes a drive pod for a multi-hull apparatus composed of at least one hydropneumatic cylinder, a propulsion device and a propeller. A propulsion system for a multi-hull apparatus composed of a plurality of drive pods which are attached to the hull of the apparatus and provide adjustability for varying ocean conditions is also an object of the present invention.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to the field of boat hull designs.  
         BACKGROUND OF THE INVENTION  
         [0002]    It is well known in the industry that watercraft with a multi-hull design provide better seakeeping in moderate-to-high wave conditions than monohull vessels. Multi-hull ships can be designed to experience only one-half to one-fifth of the heave, pitch, and roll motions of a monohull vessel of equal displacement in seas driven by wind speeds above 20 knots.  
           [0003]    An additional benefit of multi-hull designs is they can travel at faster speeds than a monohull design. The wave penetrating features of a multi-hull design allow the watercraft to also maintain course and speed during sea conditions that would otherwise defeat a monohull&#39;s ability to maintain the same course and speed.  
           [0004]    However, an inherent problem with multi-hull designs is, in the event of a rollover, they do not return upright once capsized. A multi-hull vessel is equally stable capsized as it is upright. Monohull vessels do not have this problem.  
           [0005]    Through innovative designs and concepts, various hull designs have been introduced. In an article titled “Variable Draft Broadens SWATH Horizons” in the April 1994 issue of Proceedings, improvements are made to the design known as Small Waterplane Area Twin-Hull (SWATH) ships. The SWATH design for this particular boat utilizes struts that are aligned on the centerline of the lower hull. The lower hull&#39;s rectangular cross sections enhance seakeeping at deeper drafts and give best propulsion at transit depths. The center bow provides a cushion against slamming and affords convenient overboard access for handling equipment. Rectangular hull forms supportive of the SWATH design are less expensive to fabricate and outfit than conventional hull designs.  
           [0006]    The U.S. Navy test vessel, Sea Shadow, was built to test several aspects of maintaining stealthiness at sea, including low radar visibility, quietness to sonar sensors and minimizing wake. An article titled “The Secret Ship” in the October 1993 issue of Popular Science discussed the unclassified parameters of this vessel. Above the waterline, the Sea Shadow&#39;s resemblance is similar to that of the U.S. Air Force F-117A stealth fighter. From the waterline down, the exact details are classified, but the ship&#39;s underwater shape is essentially a SWATH design. A pair of submerged pontoons gives the Sea Shadow its buoyancy. Running beneath the water&#39;s choppy surface layer, these pontoons cause far less of the seasickness-inspiring vertical motion inherent in traditional monohull designs.  
           [0007]    Another unique design is the trimaran hydrofoil designed and built by Greg Ketterman, as discussed in an article titled, “World&#39;s Fastest Sailboat,” in the January 1991 issue of Popular Science. The hydrofoil is a two-mast, triple-hull design that utilizes sensors forward of the outer hulls that hug the water&#39;s undulating surface, constantly adjusting the pitch of the hulls and main foils to maintain stability and minimize drag. Foot pedals control the rudder. This design is primarily for sail boats that want to maximize speed through the waters. However, this design is not suitable for large boats, and lacks a propulsion system often desired in larger boats.  
           [0008]    Another design is disclosed in U.S. Pat. No. 5,549,066 issued on Aug. 27, 1996 entitled “Triangular Boat Hull Apparatus.” This patent discloses a multi-hull design constructed from flat pieces of material instead of curved sections normally used for boat hull construction. The patent also presents a bilateral fore and aft symmetrical boat hull. Although this design is suited for rowboat sized boats and pleasure boats, the design is also inherently suited for larger boats such as destroyers.  
           [0009]    Ocean Waves, even in relatively calm seas, have amplitudes and lateral modulations. In stormy seas, those amplitudes and modulations often tear multi-hull ships apart. The current propulsion systems for large multi-hull ships lack a mechanism to cope with the up and down movement of the waves, and also lack structure to protect the multi-hull ship from being ripped apart.  
           [0010]    Therefore, a multi-hull design and propulsion system for a large boat that both protects the ship from being ripped apart by the changing amplitudes and modulations of the ocean, and provides a means for optimizing the ship&#39;s speed through varying sea conditions ship is desired in the art.  
         SUMMARY OF THE INVENTION  
         [0011]    The present invention relates to a triangular boat hull apparatus having a bow and stem wave penetrating feature. The hull is composed of one triangle overlapping two additional triangles on the port and starboard sides of the apparatus. The triangle features of the hull design run both athwartships, and from stem to stem. The invention also features a drive pod for a multi-hull apparatus including at least one hydropneumatic cylinder, a propulsion device and a propeller. The present invention also provides a propulsion system for a multi-hull apparatus having a plurality of drive pods which are attached to the hull of the apparatus and facilitate adjustability for varying ocean conditions. The multiple drive pods under the hull provide a type of centipede looking drive system.  
           [0012]    Therefore, it is an aspect of the present invention to provide a triangular boat hull apparatus that is economical to build.  
           [0013]    It is another aspect of the invention to provide a triangular boat hull that is suitable for a variety of very large sea vessels.  
           [0014]    It is another aspect of the invention to provide a triangular boat hull apparatus suitable for large sea vessels that has dual ended fore and aft wave penetrating features in order to provide added strength compared to other types of wave penetrating hull designs.  
           [0015]    It is another object of the invention to provide a triangular boat hull apparatus that is both air and water tight, so that in the event of a roll-over, no water would enter.  
           [0016]    It is another object of the invention to provide a triangular boat hull apparatus where the inherent design of the hulls prevents the multi-hull boat from being torn apart in inclement weather.  
           [0017]    It is another object of the invention to provide a triangular boat hull apparatus that has dual ended fore and aft wave-penetrating features in order to provide greater stability, particularly when the wave motion is severe.  
           [0018]    It is another object of the invention to provide a drive pod that is capable of incorporating diesel, electric, or waterjet propulsion engines.  
           [0019]    It is another object of the invention to provide a drive pod that incorporates either a single or dual propeller.  
           [0020]    It is another object of the invention to provide a drive pod with a hydropneumatic cylinder that can be adjusted to meet operating conditions on the ocean.  
           [0021]    It is another object of the invention to provide a propulsion system for a multi-hull apparatus where multiple drive pods are attached under the hull of the apparatus.  
           [0022]    It is a further object of the invention to provide a propulsion system for a multi-hull apparatus that can be easily modified to be suitable to any sized multi-hull apparatus.  
           [0023]    It is a further object of the invention to provide a propulsion system for a multi-hull apparatus that provides the strength needed to resist the lateral modulations of ocean waves.  
           [0024]    It is a final object of the invention to provide a propulsion system that can be adjusted to meet a variety of operating conditions.  
           [0025]    These aspects of the invention are not meant to be exclusive and other features, aspects, and advantages of the present invention will be readily apparent to those of ordinary skill in the art when read in conjunction with the following description, appended claims and accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]    [0026]FIG. 1 is an end (athwartships) view of the multi-hull apparatus.  
         [0027]    [0027]FIG. 2 is an end (athwartships) view of the cut-away port hull of the multi-hull apparatus  
         [0028]    [0028]FIG. 3 is an end (athwartships) view of the multi-hull apparatus for a propulsion system.  
         [0029]    [0029]FIG. 4 is an end (athwartships) view of the drive pod.  
         [0030]    [0030]FIG. 5 is a top view of the drive pod.  
         [0031]    [0031]FIG. 6 is a fore and aft view of the drive pod.  
         [0032]    [0032]FIG. 7 is an end (athwartships) view of the propulsion system retracted in the multi-hull apparatus.  
         [0033]    [0033]FIG. 8 is an end (athwartships) view of the propulsions system extended from the multi-hull apparatus.  
         [0034]    [0034]FIG. 9 is a fore and aft view of the propulsion system retracted in the multi-hull apparatus.  
         [0035]    [0035]FIG. 10 is a fore and aft view of the propulsion system extended in the multi-hull apparatus. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0036]    Referring first to FIG. 1, the preferred embodiment of the multi-hull apparatus  10 , the apparatus  10  is made up of a port hull  20 , a starboard hull  22  and a center hull  24 . As depicted in FIG. 1, the port hull  20  and starboard hull  22  are of equal dimensions and are each connected to the center hull  24 . The top  26  of the multi-hull apparatus  10  is depicted for illustration purposes only. The top  26  is not necessarily flat, but rather the top portion of any ship design commonly known to those skilled in the art can be dimensioned and placed in the top  26  position on the multi-hull apparatus  10 .  
         [0037]    Still referring to FIG. 1, the multi-hull apparatus  10  is constructed entirely from flat pieces of material instead of curved sections normally used for hull construction. Apparatus  10  can be sized for a variety of watercraft. The apparatus  10  design will inherently displace a large amount of water thus can be used for larger ships carrying larger loads. Examples of these types of watercraft are destroyers or cargo ships. Building watercraft of various sizes will require scaling the dimensions accordingly using techniques well known in the art. The preferable material selected for construction is molded fiberglass. Steel and other types of material typically used in the boat construction industry, including exotic materials, could also be used.  
         [0038]    The multi-hull apparatus  10  is depicted in FIG. 1 as having three hulls. However, this is for illustrative purposes only. The invention is intended for any number of hull multi-hull watercraft. Thus, depending on the size of the watercraft in which the multi-hull apparatus  10  is intended, the number of hulls will increase accordingly. The minimum three hull multi-hull apparatus is illustrated. However, increasing the number of hulls can easily be designed by a person of ordinary skill in the art by simply continuing the pattern evenly on both sides of the multi-hull apparatus  10 .  
         [0039]    The wave penetrating section of the hull will be discussed first. The center hull  24  overlaps the port hull  20  and starboard hull  22 . FIG. 1 shows the hidden lines for illustration purposes. The port hull  20  and starboard hull  22  are of equal dimensions and are also mirror images of one another. Referring now to FIG. 2, a cut-away athwartships end view of the port hull  20 , which is a mirror image of the starboard hull  22  is shown.  
         [0040]    Referring again to FIG. 1 the center hull  24  and the port hull  20  and stern hull  22  are preferably isosceles triangles with equal dimensions of 40 feet for edge  28 ,  30 ,  32 , 28.7 feet for edges  34 ,  36 ,  38 , 40 ,  42 ,  44 . The angle formed by edged  34  and  28 ,  36  and  28 ,  42  and  32 ,  44  and  32 , and  40  and  30  and  38  and  30  are each 60 degrees. 60° angles are formed at the intersection of  40  and  38 ,  34  and  36 , and  42  and  44 . The vertexes  46 ,  48 ,  50  will be under water when the watercraft is at sea.  
         [0041]    The fore and aft triangular shapes used to provide the wave penetrating section improve the strength of multi-hull apparatus  10  in both compression and tension so that heavy sea conditions will not buckle and pull apart multi-hull apparatus  10 . The dimensions and angles provided for the athwartships hull sections  20 ,  22 , and  24  can vary to correspond with other dimensions selected for the desired size of triangular boat hull apparatus  10  to be built.  
         [0042]    Referring next to FIG. 3, another embodiment of the multi-hull apparatus  10  is shown. In this embodiment, the multi-hull apparatus  60  is designed to hold a propulsion system. The apparatus  60  varies from apparatus  10  slightly, but has the same dimensions as multi-hull apparatus  10 . The center hull  62 , port hull  64 , and starboard hull  66  are substantially triangular, but in place of a vertex, the bottom of the hull  68 ,  70 ,  72  is flattened. As shown in FIG. 1, the imaginary line  52  represents the cut-off region that produces the main difference between apparatus  10  and apparatus  60 . Referring back to FIG. 3, to compensate structurally for the lack of triangles in these regions, the multi-hull apparatus  60  incorporates many triangles throughout its design. FIG. 3 exemplifies these triangles formed in the hull. Ocean waves, even in relatively calm seas have amplitudes and lateral modulations. In stormy seas those amplitudes and modulations often tear multi-hull ships apart. In the multi-hull apparatus  60 , the strength of triangles provides the structural strength to keep the multi-hull apparatus  60  from being damaged.  
         [0043]    The multi-hull apparatus  60  has compartments  74 ,  76 ,  78  which are designed to hold a propulsion system. In other embodiments of the multi-hull apparatus, there are more than three hulls, and in these embodiments, additional hulls will have compartments also. Thus, for example, in a 40 hull destroyer, there would be 40 compartments for 40 parts of the propulsion system.  
         [0044]    Referring next to FIG. 4, the drive pod  80  is shown. In the preferred embodiment, the drive pod  80  consists of a hollow component  82 , a propeller  84 , a propulsion device  86  inside the hollow component  82 , two cylinders  88 , 90  and two poles  92 , 94 . The hollow component  84  contains the propulsion device  86 . In its preferred embodiment, the hollow component is rectangular and has a width dimension  96  of 8 feet, and a height of 12 feet. In other embodiments, the hollow component  82  substantially triangular. The hollow component  82  is preferably made of fiberglass, however, as noted above, other materials used in ship construction can also be used. The hollow component  82  is watertight and is designed to fit into the compartments  74 , 76 , 78  shown in the multi-hull apparatus  60  in FIG. 3.  
         [0045]    The propeller  84  is shown in its preferred embodiment to be a four bladed propeller. The propeller  84  is made of steel. However, the propeller could be made of aluminum or any other non-corroding material. In other embodiments, the propeller  84  is a three bladed propeller, or, in place of a single propeller, there are multiple propellers, or waterjets, etc.  
         [0046]    The propulsion device  86  is located inside the hollow compartment  82 . It is connected to the propeller  84 , and drives the propeller  84 . In its preferred embodiment, the propulsion device  86  is a 2,000 Horse Power Diesel engine and is approximately 5 feet wide and 15 feet long. In other embodiments, the propulsion device  86  is a 2,000 Horse Power electric motor, or a water jet drive.  
         [0047]    The cylinders  88  and  90  are hydropneumatic cylinders and have a pole  92 ,  94  located inside each cylinder  88 ,  90 . The poles  92 , 94  are connected inside the hollow compartment  82  to the travel stop  98 . The hydropneumatic cylinders  88 , 90  have an internal variable pressure. This pressure is adjustable. Depending on the pressure inside the hydropneumatic cylinders, the pressure causes the pole  92 , 94  to either retract into the cylinder  88 , 90  or extend out of the cylinder  88 ,  90 . Consequently, this retraction or extension of the poles  92 , 94  causes the distance between the cylinder and the hollow compartment to change.  
         [0048]    The cylinders  88 ,  90  are preferably made of steel, and the poles  92 , 94  are also steel. In other embodiments, the cylinders  88 , 90  and poles  92 , 94  are made from aluminum or any other non-corrosive material.  
         [0049]    [0049]FIG. 6 is a side view of the drive pod  80  exemplifying that the drive pod  80  is designed to be incorporated inside the compartments  74 ,  76 ,  78  of the multi-hull apparatus  60 . The top portion  106  of the drive pod  80  remains in the hull, while the bottom portion  104  extends below the hull. In its preferred embodiment, the top portion  106  of the drive pod  80  has a height  102  of 12 feet, a width  108  of 30 feet, while the bottom portion  104  has a height  96  of 8 feet and a width  108  of 30 feet. The dimensions will vary according to the size of the multi-hull apparatus  60  and the compartment  74 ,  76 ,  78 . The provided dimensions are for illustrative purposes only and are not intended to be the only dimensions possible, rather, the proportions are the preferred embodiment.  
         [0050]    The propulsion system for a multi-hull apparatus  110  is shown in FIG. 7. Since the multi-hull apparatus  60  is symmetrical, only one section (the center hull  62  with the starboard hull  66 ) of the propulsion system for a multi-hull apparatus  110  need be detailed. One of ordinary skill in the art can apply the given dimensions to the other side of the propulsion system for a multi-hull apparatus  110 . The center hull  62  has a width  120  of 40 feet and a height  122  of 28 feet. The distance  124  represents the pitch distance and is 20 feet.  
         [0051]    In FIG. 7, the compartments  74 ,  76 ,  78  of the multi-hull apparatus  60  are filled with drive pods  80  and are shown retracted into the hull  112  of the multi-hull apparatus  60 . The bottom portion  104  of the drive pod  80  is located in the bottom hull  114  of the multi-hull apparatus  60  and consists of the hollow compartment  82 , the propulsion device  84  and the propeller  86 . The top portion  106  of the drive pod  80  is located in the top hull  116  of the multi-hull apparatus  60  and consists of the cylinders  88 , 90  and the poles  92 , 94 . The height  96  of the drive pods  80  provides amplitude to cope with the up and down movement of the waves. In total, there is approximately 18 feet of hull in the supporting triangles before the hull would bottom out on a wave top.  
         [0052]    The drive pods  80  have side skirts  118  having a height of 12 feet. These side skirts  118  on the drive pods  80  bear against the triangles of the multi-hull apparatus  60 , and together the side skirts  118  and the triangles provide the strength needed to resist the lateral modulations always present in ocean waves.  
         [0053]    Referring next to FIG. 8 showing the propulsion system for a multi-hull apparatus  110  where the drive pods  80  are extended. Even when fully extended, there is at least 4 feet of bearing surface  126  between each drive pod  80  and the triangular extension  128  of the hull. Therefore there is 240 ft 2  or a 66% bearing surface on both sides of the drive pod.  
         [0054]    [0054]FIG. 9 is a side view of the bottom hull  114  of the propulsion system for a multi-hull apparatus  110  retracted. FIG. 10 is a side view of the bottom hull  114  of the propulsion system for a multi-hull apparatus  110  extended. The pressure inside the hydropneumatic cylinders  88 , 90  can be adjusted to meet operating conditions during the time of transit to provide optimum operation of the drive pods as conditions change. For illustration purposes, FIG. 9 and FIG. 10 show the versatility of the multi-hull apparatus  60  design, where the size of design can be easily adapted to a vessel of any size.  
         [0055]    Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions would be readily apparent to those of ordinary skill in the art. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.