Abstract:
The present disclosure relates to a boat including a hull having an interior region. The boat also includes an insert mounted within the hull. The insert includes a bottom piece having a bottom side that complements and nests within the interior region of the hull. The insert also includes a top piece secured to the bottom piece. The top and bottom pieces cooperate to define an inner foam chamber. The insert further includes a volume of foam positioned within the foam chamber.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to boats. More particularly, the present invention relates to boats having fiberglass hulls and to methods for manufacturing such boats. 
     BACKGROUND OF THE INVENTION 
     Boat hulls have historically been made of many different types of material such as aluminum, steel or wood. Another common material used in the manufacture of boat hulls is a laminate material made of fiberglass-reinforced resin. 
     Open face molds are frequently used to manufacture fiberglass hulls. To make a hull with an open face mold, a layer of gel coat is frequently first applied to the mold. Next, a barrier layer is often applied to the gel coat. Finally a layer of fiberglass-reinforced resin is applied to the barrier layer. When the hull is removed from the mold, the gel coat provides a smooth, aesthetically pleasing outer surface of the hull. The barrier layer prevents the fiberglass from printing or pressing through the gel coat. The fiberglass provides the hull with structural rigidity. 
     With fiberglass boats, it is often desirable to inject foam into foam compartments formed within the boats. The injection of foam presents several problems. For example, when foam is injected into a boat, pressure generated by the foam injection process can cause portions of the boat to bow or buckle outward thereby negatively affecting the appearance and structural integrity of the boat. This can be particularly problematic with respect to unsupported parts manufactured by injection molding or resin transfer molding operations. Also, to access foam chambers within a boat, it is often necessary to drill holes through portions of the boat. This is problematic because the drilling of holes can cause the aesthetically pleasing outer gel coat surface to be damaged. The repair of such damage can be time consuming. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention relates to a boat including a hull having an interior region. The boat also includes an insert mounted within the hull. The insert includes a bottom piece having a bottom side that complements and nests within the interior region of the hull. The insert also includes a top piece secured to the bottom piece. The top and bottom pieces cooperate to define an inner foam chamber. The insert further includes a volume of foam positioned within the foam chamber. 
     Another aspect of the present invention relates to a method for manufacturing a boat. The method includes providing a hull. The method also includes providing an insert having a top piece and a bottom piece that cooperate to define a foam chamber. The method further includes injecting foam into the foam chamber of the insert, and securing the insert within the hull. 
     A further aspect of the present invention relates to a method for making a boat including providing a boat structure including a hull and a deck, supporting the boat structure between at least two mold pieces, and injecting foam into a foam chamber defined within the boat structure. The foam is injected in the foam chamber while the boat structure is concurrently supported by the at least two mold pieces. 
     A variety of advantages of the invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practicing the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several aspects of the invention and together with the description, serve to explain the principles of the invention. A brief description of the drawings is as follows: 
     FIG. 1 is a perspective view of a boat constructed in accordance with the principles of the present invention; 
     FIG. 2 is an exploded, perspective view of the boat of FIG. 1; 
     FIG. 3 is a cross-sectional view taken along section line  3 — 3  of FIG. 1; 
     FIG. 4 is a cross-sectional view of an insert used in the boat of FIG. 1, the insert is shown supported between top and bottom molds; 
     FIG. 5 is a plan view illustrating an adhesive pattern used in the hull of the boat of FIG.  1 ;and 
     FIG. 6 is a cross-sectional view of an alternative boat in the process of having foam injected within a foam chamber of the boat. 
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to exemplary aspects of the present invention that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     FIG. 1 is a perspective view of a boat  20  constructed in accordance with the principles of the present invention. The boat  20  includes a hull  22  (shown in phantom line) including a bow  24  positioned opposite from a stern  26 . A keel  28  extends between the bow  24  and the stern  26 . Chines  30  and strakes  27  (best shown in FIG. 3) are located on port and starboard sides of the hull  22 . The boat  20  also includes a pan or insert  32  mounted within the hull  22 . The insert  32  provides structural rigidity or reinforcement to the hull  22 . As shown in FIG. 2, the insert  32  is formed by a top piece  36  and a bottom piece  38 . 
     The top piece  36  of the insert  32  includes a generally planar, horizontal top surface that forms an upper deck or platform  34  of the boat  22 . The top piece  36  also includes first and second supports  41  and  42 . The supports  41  and  42  extend widthwise across the top piece  36  and are configured for providing structural reinforcement to the hull  22 . The top piece  36  further includes an upper lip or flange  50 . The flange  50  projects transversely outward from the top edge of the top piece  36 , and extends generally about a perimeter of the top piece  36 . 
     Still referring to FIG. 2, the top piece  36  also defines a plurality of internal compartments. For example, the top piece  36  defines a front storage compartment  44  positioned in front of the second support  42 , a middle fuel-tank compartment  46  positioned between the first and second supports  41  and  42 , and a rear engine compartment  48  positioned behind the first support  41 . The front and middle compartments  44  and  46  preferably can be covered with removable panels (not shown). 
     Referring again to FIG. 2, the bottom piece  38  of the insert  32  includes an interior region  52  sized for receiving the top piece  36 . The interior region  52  is configured to generally complement a bottom profile of the top piece  36  such that the top piece  36  can nest within the interior region  52 . FIG. 3 shows the top piece  36  nested within the bottom piece  38 . As so nested, keel regions  53  of the top and bottom pieces  36  and  38  engage one another in a parallel relationship. Additionally, chine regions  55  of the top and bottom pieces  36  and  38  engage one another in a parallel relationship. In the keel and chine  53  and  55  regions, no substantial gap exists between the top and bottom pieces  36  and  38 . By contrast, between the keel and chine regions  53  and  55 , the top and bottom pieces  36  and  38  separate from one another so as to define foam chambers  54  having generally triangular cross-sections. As shown in FIG. 3, each foam chamber  54  is defined by an upright wall  56  of the top piece  36 , a horizontal wall  58  of the top piece  36 , and an inclined wall  60  of the bottom piece  38 . Each foam chamber  54  is filled with a volume of foam  73 . 
     A bottom side or bottom profile of the bottom piece  38  is configured to complement and nest within an interior region  62  (best shown in FIG. 2) of the hull  22 . When nested within the hull  22  as shown in FIG. 3, substantially the entire bottom surface of the bottom piece  38  makes generally parallel contact with the interior region  62  of the hull  22 . Also, a top flange  64  that extends about the perimeter of the bottom piece  38  seats upon a shoulder  66  defined by the interior region  62  of the hull  22 . Further, a plurality of strake projections  68  formed on the bottom of the bottom piece  38  fit within complementary strake recesses  70  formed along the interior region  62  of the hull  22 . 
     It is preferred for the top piece  36  to be manufactured by an open face molding process. To practice such a process, a layer of gel coat (e.g., about 0.020-0.024 inches thick) is first applied to an open face mold. Next, a layer of reinforcing chop material and resin (e.g., about 0.090-0.100 inches thick) is applied over the gel coat. For example, fiberglass can be applied by blowing a mixture of resin and fiberglass chop strand onto the gel coat layer to form a wet laminate layer. The wet laminate layer is then rolled out, and reinforcements can be laid within the wet laminate material. Exemplary types of reinforcements include aluminum plates/members for mounting seats, coremat for preventing the seat mounts from printing through the fiberglass laminate, and wood reinforcements for providing a motor mount and for providing a tank cover and storage lid hold-down function. Upon curing, the laminate preferably has a thickness of about 0.100 inches and forms a generally rigid shell containing the reinforcements. 
     While it is preferred to use an open face molding process, it will be appreciated that the top piece  36  can be manufactured by any number of known techniques. For example, the top piece  36  can be manufactured by a resin transfer molding process, an injection molding process, or any other known technique. U.S. application Ser. No. 08/715,533 filed on Sep. 18, 1996 and entitled Apparatus For Molding Composite Articles, which is hereby incorporated by reference, discloses an exemplary resin transfer molding process. It will also be appreciated that the hull  22  and the bottom piece  38  can be manufactured by techniques similar to those described with respect to the top piece  36 . For example, in one particular embodiment, the bottom piece  38  can be manufactured by an open face molding process in which a fiberglass laminate is applied to an open face mold. In such an embodiment, no gel coat layer, barrier layer or reinforcements are used, and the bottom piece  38  can have a laminate thickness of about 0.06 inches. 
     In one particular non-limiting embodiment of the hull  22 , the hull has an outer gel coat layer of about 0.024 inches, and intermediate barrier layer of about 0.035 inches, and an inner fiberglass layer of about 0.25-0.375 inches. The barrier layer prevents the fiberglass from pressing through the gel coat. 
     To assemble the insert  32 , a layer of adhesive (e.g., a polyester putty) is preferably spread either along the bottom surface of the flange  50 , or along the top surface of the flange  64 . At the time the adhesive is applied, the top piece  36  is preferably supported by a first open face mold  72  (shown in FIG. 4) and the bottom piece  38  is supported by a second open face mold  74  (shown in FIG.  4 ). While supported by their corresponding open faced molds  72  and  74 , the top piece  36  is placed or nested within the interior region  52  of the bottom piece  38 . As so positioned, the first and second open faced molds  72  and  74  are clamped together thereby compressing the adhesive between the flanges  50  and  64 . 
     With the two open face molds  72  and  74  clamped together, foam  73  (e.g., a polyurethane loam that becomes generally rigid upon curing) is preferably injected into the foam chambers  54 . Preferably, the foam  73  is injected through  10  to  12  holes that have been pre-drilled through either the bottom piece  38  or the top piece  36 . During the injection process, the open face molds  72  and  74  prevent the top and bottom pieces  36  and  38  from bowing or buckling away from one another. Consequently, the molds  72  and  74  assist in improving the aesthetic appearance and design tolerance of the insert  32 . 
     Referring to FIG. 4, the pre-drilled holes have been located in two different locations. For example, a first set of pre-drilled holes  76  have been drilled through the inclined walls  60  of the bottom piece  38 . The first set of holes  76  are in fluid communication with the foam chambers  54 . Nozzles or conduits  78  that extend through the second open face mold  74  are used to inject the foam into the foam chambers  54  through the first set of openings  76 . 
     A second set of openings  80  have been pre-drilled through the upright walls  56  of the top piece  36 . Similar to the openings  76 , the openings  80  are in fluid communication with the foam chambers  54 . Nozzles or conduits  82  that extend through the first open face mold  72  are used to inject foam into the foam chambers  54  through the second set of openings  80 . 
     The locations of the first and second sets  76  and  80  of openings are advantageous because such openings are located at inconspicuous positions. Consequently, it is not necessary to refinish these regions after the injection molding process. By contrast, the horizontal, top wall  58  of the top piece  36  forms the platform  34  of the boat  22 . Holes through this region would be highly visible and would damage the outer gel coat finish. Consequently, holes through the horizontal, top wall  58  would most likely necessitate refinishing of the top surface  40  of the top piece  36 . 
     After the foam  73  has cured within the foam chambers  54 , the insert  32  is removed from the open face molds  72  and  74 , and is inserted into the interior region  62  of the hull  22 . An adhesive material (e.g., an adhesive sold by Applied Products, Inc. under the name Plexus) is preferably used to secure the insert  32  within the hull  22 . A solvent can be used to prepare or clean the surface of the hull prior to applying the adhesive. 
     As shown in FIG. 5, a plurality of beads  84  of adhesive are applied to the interior region  62  of the hull  22  prior to inserting the insert  32  therein. When the insert  32  is inserted within the hull  22 , an adhesive bond is formed between the hull  22  and the bottom surface of the bottom piece  38 . 
     The beads  84  of adhesive are preferably arranged in a pattern for allowing water to drain between the hull  22  and the bottom piece  38 . Each bead  84  is generally U-shaped and includes two legs  86  that are generally perpendicular with respect to the keel  28 . Rounded ends  88  of the beads  84  are located adjacent the port and starboard sides of the hull  22 . Open ends  90  of the beads  84  are located adjacent to the keel  28  of the hull  22 . The legs  86  of the beads are aligned generally parallel to one another. Flow passageways  92  are defined between each of the beads  84 . The flow passageways  92  allow water to drain along the interior region  62  of the hull  22  from the chines  30  toward the keel  22 . A drainage opening (not shown) is preferably located at the keel  28  adjacent to the stern  26  for allowing water to drain from the hull  22 . The particular configuration of the adhesive beads  84  is advantageous because it prevents water from being captured or otherwise retained between the insert  32  and the hull  22 . Retained water is problematic because at cold temperatures the water can freeze and cause cracking of the hull  22 . 
     In addition to the U-shaped beads  84  of adhesive, a layer of adhesive can also be applied about the shoulder  66  of the hull  22 . This adhesive extends about the perimeter of the bottom piece  38  of the insert  32 , and forms a sealed bond between the bottom side of the flange  64  and the top side of the shoulder  66 . 
     FIG. 6 is a cross sectional view of an alternative boat  20 ′ constructed in accordance with the principles of the present invention. The boat  20 ′ is in the process of being injected with foam. Parts similar to those previously described with respect to the embodiment of FIGS. 1-5 will be assigned like numbers with the addition of apostrophes to distinguish the embodiments. 
     The boat  20 ′ has a similar configuration as the boat  20 , except the bottom piece  38  of the insert  32  has been eliminated. Instead, a one-piece insert  36 ′ is mounted within a hull  22 ′ of the boat  20 ′. Foam chambers  54 ′ are defined between the insert  36 ′ and the hull  22 ′. 
     As shown in FIG. 6, the insert  36 ′ is supported within a first open mold  72 ′ and the hull  22 ′ is supported in a second open mold  74 ′. The open molds  72 ′ and  74 ′ are clamped together such that the boat  20 ′ is contained between the molds  72 ′ and  74 ′. 
     A set of openings  80 ′ have been pre-drilled through upright walls  56 ′ of the insert piece  36 ′. The openings  80 ′ are in fluid communication with the foam chambers  54 ′. Nozzles or conduits  82 ′ that extend through the first open face mold  72 ′ are used to inject foam into the foam chambers  54 ′ through the second set of openings  80 ′. 
     With regard to the foregoing description, it is to be understood that changes may be made in detail, especially in matters of the construction materials employed and the shape, size and arrangement of the parts without departing from the scope of the present invention. It is intended that the specification and depicted aspects be considered exemplary only, with a true scope and spirit of the invention being indicated by the broad meaning of the following claims.