Abstract:
A stretch hull design comprises of a stern float and a bow float joined longitudinally to each other at some distance apart by a beam making an otherwise short floats a long correspondingly stable hull. Having a little mass toward the middle in the form of a beam, the hull is relatively cheaper to build per lineal unit of length and less subjected to the effect of the waves contributing to a better ride quality and reduces structural stress. It provides a large potential space limited only by the displacement of the floats and the length of the beam. The beam also acts as ballast, keel or centerboard preventing the craft from capsizing and facilitates the mounting of parts in enhancing the performance of the craft.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a watercraft&#39;s hull design, particularly to the improvement of the hull stability, performance and cost effectiveness.  
         BACKGROUND  
         [0002]    The stability, performance and cost of the hull of the watercrafts are basically a function of the length of the hull of the craft.  
           [0003]    As the crafts sail through particularly on rough water the bottom of the hull makes an angle with the horizontal plane that changes back and forth from either positive to negative angles. Like the chord of a circle, the magnitude of this angle is greater on a short hull than on a long hull. In effect the magnitude of this angle determined the quality of the ride on a crafts and as the angle gets stiffer correspondingly the quality of the rides becomes more uncomfortable and even dangerous. It could lead the craft to fly or dive uncontrollably, which usually happens on speedboats. On the contrary the craft having a long hull the said angle is relatively small contributing to a better ride and stability.  
           [0004]    While a craft having a long hull is relatively stable, the effect of the waves is a big concerned structurally. For example, a craft having its middle body on the crest of the wave while the stem and the bow overhanging on the ascending and receding sides is subjected to an excessive structural stress. The pressure exerted by the weight of the stern and the bow overhanging stretches the top and compresses the bottom of the hull. The same is true with the trough of the wave underneath the middle of the hull only in a reverse fashion and as the crafts moves from wave to wave the hull is repeatedly under a reciprocating stress that a poorly build craft somehow ruptured. A structurally sound hull on the other hand of sufficient length are typically wide and bulky and therefore too expensive to build.  
           [0005]    Other factors that relate to the present invention are watercrafts having an inflatable hull. Inflatable crafts are relatively short and having a collapsible lightweight hull makes the craft easy to maintain, transport and store. Inflatable crafts are very popular in the market and they are used in a variety of ways, outfitted with a motor or in most cases just being paddled. Rarely inflatable are powered by sail and the much smaller units are so unstable that it is being categorized as toys in the market place.  
         SUMMARY  
         [0006]    The present invention features a watercraft&#39;s hull design that is cost effective per lineal unit of length and less subjected to the effect of the waves at sea.  
           [0007]    The hull according to the present invention comprises basically of a stern float and a bow float joined longitudinally to each other preferably at some distance apart by at least one elongated laterally narrow but rigid structure preferably in the form of a beam or beam assembly making an otherwise unstable short floats a long correspondingly stable hull.  
           [0008]    Having a very small mass toward the middle in the form of a beam makes the hull relatively cheaper to build per lineal unit of length than the prior art. This makes a watercraft of sufficient length affordable to the mass market. Also having a small and correspondingly lightweight structure toward the middle makes the crafts less subjected to the effect of the waves contributing to a better ride quality and less structural stress.  
           [0009]    The hull of the present invention relatively having a small floats usually in the form of an enclosed capsule, in contrary provides a very large potential space limited only by the displacement of the floats and the length of the beam. The beam in addition is usually designed acting as ballast, keel or centerboard that helps prevent the craft from capsizing and facilitates the mounting of parts in enhancing the performance of the craft. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    In the accompanying drawings, which illustrate various exemplary embodiment of the present invention:  
         [0011]    [0011]FIG. 1 is a side elevation of a hull of a powerboat;  
         [0012]    [0012]FIG. 2 is a plan view of FIG. 1;  
         [0013]    [0013]FIG. 3 is an enlarged partial elevation of FIG. 1;  
         [0014]    [0014]FIGS. 4A and B is a cross-sections along line  4 - 4  of FIG. 1;  
         [0015]    [0015]FIG. 5 is a view like FIG. 1, showing an alternative embodiment of the invention, particularly a sailboat;  
         [0016]    [0016]FIG. 6 is a plan view of FIG. 5;  
         [0017]    [0017]FIG. 7 is a front elevation of FIG. 5;  
         [0018]    [0018]FIG. 8 is a cross-section along line  8 - 8  of FIG. 5;  
         [0019]    [0019]FIG. 9 is a cross-section along line  9 - 9  of FIG. 5;  
         [0020]    [0020]FIG. 10 is a view like FIG. 1, showing another alternative embodiment of the invention, particularly a sport sailboat;  
         [0021]    [0021]FIG. 11 is a plan view of FIG. 10;  
         [0022]    [0022]FIG. 12 is an enlarged partial cross-section along line  12 - 12  of FIG. 10;  
         [0023]    [0023]FIG. 13 is an enlarged partial elevation of FIG. 10;  
         [0024]    [0024]FIG. 14 is a view like FIG. 1, showing still another alternative embodiment of the invention, an inflatable hull sport sailboat; and  
         [0025]    [0025]FIG. 15 is a plan view of FIG. 14. 
     
    
     DETAILED DESCRIPTION  
       [0026]    Referring generally to the accompanying drawings, particularly to FIGS. 1, 5,  10  and  14 , there are illustrated different types of watercrafts but basically having the same hull design, hull  20 A,  20 B,  20 C and  20 D each having provided with a stem float  21  and bow float  22  joined longitudinally to each other at some distance apart by a beam or beam assembly  23 . The float  21  and  22  varies in shape and form from one type of crafts to the other as intended. The beam  23  varies likewise but preferably, in the form of a tube as shown in FIG. 4A or I-beam as shown on FIG. 4B, each having a stern portion  23   s  and a bow portion  23   b  connected by a means to float  21  and  22  respectively, and a middle portion  23   m.  The middle portion  23   m  of the beam  23  predetermined the additional length possibly needed in the process of making an otherwise short floats  21  and  22  a much longer hull  20 A,  20 B,  20 C and  20 D respectively.  
         [0027]    Specifically as illustrated in FIGS. 1, 2,  3  and  4 , there is a powerboat hull design  20 A of the present invention. In addition to the basic features of the present invention, hull  20 A is provided with an optional platform  24 , preferably in the form of a heavy duty net with tubular framework, secured at a predetermined height from the surface by a means to the sides of the hull  21 ,  22 . The platform  24  is further supported by column  25  attached to the beam  23  in cases the hull is extremely long. Accordingly the platform  24  provide a very long open space indeed yet without compromising the stability of the hull of the present invention while the float  21  and  22  in contrast are intended to be sufficient but relatively small enclosed spaces, bringing the cost down.  
         [0028]    Hull  20 A is a hydrofoil version of the present invention, float  21 ,  22  are provided with respective pair of fins  26  and  27  designed to lift the hull  20 A as it moves through the surface  28  powered by a pair of out-board motors  29 , and/or motors  30 . The fins  26 ,  27  makes the float  21 ,  22  off the waves contributing to a smooth ride while its long torpedo shaped beam  23  maintained a relatively straight travel path just below the surface. The fins  26  and  27  are connected by a means from both sides of the said floats extended downwardly to a point and laterally turned secured centrally to the beam  23 .  
         [0029]    As illustrated in FIGS. 5, 6,  7 ,  8 , and  9 , there is a sailboat hull design  20 B similar to hull  20 A with a modified float  21 ,  22 . The stem float  21  (and likewise the bow float  22 ) is provided having the middle area  21   n  (FIG. 9) dropped more downwardly lifting in effect the wider portion  21   w  off the surface  31 . This feature provides a sufficient vertical space on the axles  32  of the said floats and having a wedge shaped portion  21   n  of the floats on the surface  31 . The hull  20 B having plenty of lineal space, is outfitted with two short masts  32  and  33  instead of one twice as high as being done in prior art, making the sail and rigging of the present invention cheaper and easier to operate and maintain. A ladder subassembly  34  is provided with its lower end sets securely pivotal on the beam  23 . Again, hull  20 B is like hull  20 A having a sufficient enclosed space on both float  21 ,  22  and a very large deck space on the contrary making the sailboat of the present invention a pleasure crafts for sailing.  
         [0030]    A sport sailboat of the present invention is illustrated in FIGS. 10, 11,  12  and  13 , the hull design  20 C having provided with a composite catamaran type stem float  21  made from plurality of modular pontoons  21   a,    21   b,    21   c  connected by a tubular spar  35  and  36  running through a predetermined lateral holes  37  and  38  on each pontoon and the bow float  22  consists of an inline formation of pontoon  22   a  and  22   b,  joined longitudinally to each other at some distance apart by beam assembly  23 , through a predetermined longitudinal hole  39  of the respective pontoon. An L-shaped end cap  40  is provided having its horizontal leg securely plugged to the end of a rectangular tubular beam  23  and its vertical leg held closed to the respective composite float  21 ,  22 . A decorative rope  41  runs through holes  37 ,  38  or around the tube  35 ,  36  bundles securely the respective pontoons and cap  40  to the respective rigidly fixed cleats  42 ,  43  of the beam  23 . A pivotal ladder  44  is likewise provided held in place by an end cap  40  with the upper end attached to and operated by an arm like handle  45 .  
         [0031]    The beam  23  of hull  20 C in the form of rectangular tube is designed for ease of transport and assembly. Accordingly the beam  23  is cut into two length sections, each section having one end detachably connected by a coupling means  46 , also made of a matching rectangular tube. The coupling  46  is provided with an elongated upright channel  47  with the legs of the channel faces toward the stern and having one end rigidly fixed to the upper side of coupling  46 . A support means  48  made of rod laterally fixed in between said legs of the channel  47  supporting the mast  60 . An optional telescoping rail  49  is provided for convenient held by a mounting tube subassembly  50  fixed to the channel  47  as well.  
         [0032]    The underneath face of the coupling  46  is provided with a pair of elongated plate  51  each having one end rigidly fixed to the coupling  46  and the other end extended downward provided with support means  52  in the form of a nut and bolt arrangement runs through a predetermined holes made on the plate  51  supporting a vertically retractable ballast subassembly.  
         [0033]    The ballast subassembly has an elongated upright plate  53  with two ends and toward the middle a hole is provided aligned to a matching pivotal means  52  in the form of a cylinder rigidly fixed to the plate  53 . Toward the lower end of the plate  53  a means  54  is provided also in the form of a nut and bolt arrangement with the head of the bolt rigidly fixed to the plate  53 . The bolt of means  54  supports the pivotal weight  55  through a predetermined lateral hole provided and secured by the nut of means  54 . A lever  56  made of an elongated bar formed into an L-shape is provided having one end rigidly fixed to the upper end of the plate  53 . The opposite end of lever  56  is provided with a pivotal means  57 . An L-shaped lock-handle subassembly having both legs in the form of spindles  58  and  59  and with a matching means is pivotally connected to means  57 . Accordingly the ballast subassembly is retracted upward by shifting the lever  56  passed beyond and locked to the upright  47  by turning the handle  58  upward. With the ballast retracted upward makes it possible as intended for a sailboat to sail through sallow water.  
         [0034]    The hull  20 C is provided with a detachable folding mast  60  having the lower end sets hooked to a means  48  while standing and held further by plurality of stays  61 . The mast  60  is provided with a tubular yard  62 ,  63  each having one end detachably connected to the matching horizontal cylinder of an offset cross joint  64 . The cross joint  64  having its vertical cylinder pivotal about the mast  60  is secured on top and bottom by ring  65  and  66 . The ring  65 ,  66  are fixed by a means to the mast  60  at a predetermined height from the surface. The opposite end of each yard  62 ,  63  is provided with control means that adjust the angle of the yard or sail in particular in relation to direction of the wind while sailing.  
         [0035]    Another sport sailboat of the present invention is illustrated in FIG. 14 and  15 , the hull design  20 D is similar to hull  20 C only uses an inflatable stem float  21  and an inflatable bow float  22 . A relatively short body inflatable turned into a stable sailboat indeed. Hull  20 D is designed with ease to transport and assemble as well. Each inflatable of the hull  20 D is provided with rigid board bottom  67  with a predetermined hole aligned detachably screwed to the beam  23  by a means  68 . A special clamp means  69  is generally provided securing the forward end of each inflatable to the beam  23 . Another modification made on the hull  20 C is the configuration of the beam  23 . Accordingly the stem length section of the beam  23  is bended at point  70  a certain angle downward while the bow length section is bended at point  71  oppositely a certain angle upward. In effect raises the forward portion of inflatable  21 ,  22  off the surface  72  and aim at reducing the drag while sailing.  
         [0036]    It is to be understood that the scope of the invention is to be ascertained solely by reference to the appended claims.