Abstract:
This invention is related to a lightweight composite panel and a method of making the same. The lightweight composite panel is used in the construction of cabinets and furnishings where weight must be kept to a minimum. The lightweight composite panel includes a top skin panel, at least one core frame, a bottom skin panel, and a lightweight material. The core frame is assembled from flat members that form the perimeter of the lightweight composite panel, while the top and bottom skin panel form the planar sides of the panel. The lightweight material is shaped to fill the cavity created by the top and bottom skin panels and the core frame. The components of the lightweight composite panel are pressed between corresponding mold halves, thereby taking the shape of the mold halves and forming a contoured lightweight composite panel that has the appearance of a traditional solid panel.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not applicable. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    This invention relates to a lightweight composite panel for use in furnishings and cabinets (collectively referred to as “furnishings”) in applications where the weight of the furnishings is a chief design concern. These applications are as varied as recreational vehicles, boats and aircraft. Common to all of the applications is a requirement that the weight of furnishings be kept to a minimum, without sacrificing the aesthetic appearance of the furnishings. As the panels that form the furnishings account for the majority of the weight of the furnishings, the greatest weight savings are realized by reducing the weight of the panels. 
         [0004]    Various designs for lightweight furnishings are known. Some known designs are composed of panels made of aluminum or synthetic materials such as various plastics. While these designs are lightweight in nature, they lack a visually appealing aesthetic appearance. Solid wood panels provide the desired aesthetically pleasing visual appearance, but the panels have a substantial weight, thus failing to meet the requirements for a lightweight furnishing. 
         [0005]    Consequently, what is needed is a lightweight composite panel that has an aesthetically pleasing visual appearance, but is lightweight in nature so as to be suitable for applications where weight is to be kept to a minimum, and is easily manufactured with efficient use of materials and labor. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    A brief overview of the lightweight composite panel and its method of manufacture follows immediately below. A more detailed description is provided in the Detailed Description of the Invention section. 
         [0007]    The present invention provides a lightweight composite panel and a method of manufacturing the same. 
         [0008]    The lightweight composite panel broadly includes, a top skin panel, a bottom skin panel, a core frame layer, and a lightweight material. The core frame layer is composed of a plurality of flat members that when assembled form a bounded, two-dimensionally enclosed area. A core of lightweight material of equal thickness to the core frame, and of substantially similar length and width of the bounded two dimensional area is situated within the enclosed area. An adhesive is applied to the surfaces of each layer and core. The assembly is then placed into a press that has two die halves. The assembly is pressed between the two die halves, forming the desired contour of the panel. The top and bottom skin panels, core frame layer, and core of lightweight material are therefore bonded together in a single molding and shaping process. 
         [0009]    The lightweight composite panel has the appearance of a conventional solid wood panel, but weighs substantially less than a solid wood panel of similar dimensions. In addition, the lightweight material core provides structural rigidity and sound dampening to what would otherwise be a hollow cavity. The lightweight composite panel described herein provides a significant improvement over prior designs for lightweight panels by providing a look and feel that is nearly identical to a solid wood panel. The method of manufacturing the lightweight composite panel described is a simple and efficient process that forms the panel in a single molding process, thereby reducing labor costs and manufacturing time. 
         [0010]    As will be seen from the detailed description that follows, the invention provides a lightweight composite panel and method of manufacturing the same. Additional advantages, and novel features of the invention will be set forth in part in a description which follows and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0011]    In the accompanying drawings, which form a part of the specification, and which are to be read in conjunction therewith, and in which like reference numerals are used to indicate like parts in the various views, where thicknesses and dimensions of some components may be exaggerated for clarity: 
           [0012]      FIG. 1  is an exploded view of the components of a lightweight composite panel, according to an embodiment of the present invention; 
           [0013]      FIG. 2  is a perspective view of the assembled components of a lightweight composite panel prior to being formed in a press, in accordance with an embodiment of the present invention; 
           [0014]      FIG. 3  is a section view of  FIG. 2 , in accordance with an embodiment of the present invention; 
           [0015]      FIG. 4  is an exploded cross section view of the components of a lightweight composite panel positioned in a press, prior to forming, in accordance with an embodiment of the present invention; 
           [0016]      FIG. 5  is a perspective view of the lightweight composite panel, after the forming operation has been performed in the press, in accordance with embodiments of the present invention; and 
           [0017]      FIG. 6  is a section view of  FIG. 5 , according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    Referring to the drawings in greater detail and initially to  FIG. 1 , the embodiments of the present invention are directed toward a lightweight composite panel, which is shown and designated generally by reference numeral  100 . The components of a lightweight composite panel  100  include a top skin panel  102 , a bottom skin panel  104 , a lightweight material  106 , a first core frame  109 , and a second core frame  117 . Alternative embodiments of the invention may include only one core frame or more than two core frames. 
         [0019]    The components mentioned above will now be discussed with more detail, with reference to  FIG. 1 . In one embodiment, the first core frame  109  is composed of a first flat member  108 , a second flat member  110 , a third flat member  112 , and a fourth flat member  114 . In one embodiment, the flat members  108 ,  110 ,  112 ,  114  are of substantially similar thickness and constructed of substantially similar materials. The first flat member  108  and the third flat member  112  are of substantially similar length and width. The second flat member  110  and the fourth flat member  114  are also of substantially similar length and width. 
         [0020]    The second core frame  117  is composed of a first flat member  116 , a second flat member  118 , a third flat member  120 , and a fourth flat member  122 . In one embodiment, the flat members  116 ,  118 ,  120 ,  122  are of substantially similar thickness and constructed of substantially similar materials. The first flat member  116  and the third flat member  120  are of substantially similar length and width. The second flat member  118  and the fourth flat member  122  are also of substantially similar length and width. Although not depicted in the figures, in alternative embodiments the core frame may be constructed from a single flat member, with the interior portion removed, resulting in a core frame of substantially similar dimensions as one assembled from a plurality of flat members 
         [0021]    The materials used to construct the first core frame  109  and the second core frame  117  are selected from traditional sawn lumber, plywood, oriented strand board, synthetic materials such as plastics, or any other material possessing a similar rigidity as the previously mentioned materials, yet still flexible enough to be pressed into a contoured shape. 
         [0022]    As depicted in  FIG. 1 , the flat members  108 ,  110 ,  112 ,  114  comprising the first core frame  109  are fastened together at each of their joints with a fastening means  124 . The flat members  116 ,  118 ,  120 ,  122  comprising the second core frame  117  are also fastened together at each of their joints with a fastening means  124 . The fastening means  124  may comprise a staple, a nail, a threaded fastener, an adhesive, or any other fastening means known to one skilled in the art. Although depicted in  FIG. 1  as being rectangular in overall shape, the first core frame  109  and the second core frame  117  may take other overall shapes in alternative embodiments of the invention. In alternative embodiments of the invention, the first core frame  109  and the second core frame  117  may be circular, trapezoidal, octagonal, or triangular in overall shape. These shapes are provided as examples, and are not meant to be limiting in nature. Additionally, although not depicted in  FIG. 1 , cross members similar in dimension to the flat members  112 ,  108  may be added to the first core frame  109  and second core frame  117  to increase structural rigidity and provide additional support for larger core frames. In embodiments of the invention that utilize cross members, the multiple pieces of the lightweight material  106  will be formed in the shape of the respective enclosed areas created by the cross members and the other flat members of the first core frame  109  and second core frame  117 . 
         [0023]    In the embodiment depicted in  FIG. 1 , the first core frame  109  and the second core frame  117  are utilized in the lightweight composite panel  100 . The first core frame  109  and the second core frame  117  are of substantially similar length and width, although they may differ in overall thickness. Although not depicted in  FIG. 1 , in an alternative embodiment additional core frames similar in construction to the first core frame  109  and second core frame  117  may be used in the construction of the lightweight composite panel  100 . In another alternative embodiment, only one core frame, such as the first core frame  109 , may be utilized in the construction of the lightweight composite panel  100 . 
         [0024]    As depicted in  FIG. 1 , the top skin panel  102  and bottom skin panel  104  are of substantially similar length, width and thickness. In an alternative embodiment, the thickness of the top skin panel  102  and the bottom skin panel  104  may be dissimilar The top skin panel  102  and the bottom skin panel  104  may be constructed of traditional sawn lumber, a wood veneer, or layers of wood veneer bonded together to form a single top skin panel  102  or bottom skin panel  104 . In another embodiment of the invention, the top skin panel  102  and bottom skin panel  104  may be constructed of synthetic or man-made materials. Additionally, as the bottom skin panel  104  is the surface most likely to be seen on a regular basis by an end user once the bottom skin panel  104  is incorporated into a furnishing, a higher grade or quality material may be used for the bottom skin panel  104 , while a lower grade or quality material may be used for the top skin panel  102 . The use of a lower grade or quality material for the top skin panel  102  would reduce the overall cost of the lightweight composite panel  100 , without any reduction in perceived quality or functionality by the end user. Although not depicted in  FIG. 1 , in other embodiments of the invention an additional panel, similar in length and width to that of the top skin panel  102  or bottom skin panel  104 , may be inserted in between the top skin panel and first core frame  109  or the bottom skin panel  104  and second core frame  117 . In embodiments of the invention that utilize this additional panel, the top skin panel  102  may not be as thick as the additional panel placed between the top skin panel  102  and the first core frame  109 . Accordingly, in embodiments of the invention that utilize an additional panel between the bottom skin panel  104  and the second core frame  117 , the bottom skin panel  104  may not be as thick as the additional panel. In an additional embodiments of the invention, additional panels may be utilized under both the top skin panel  102  and bottom skin panel  104 . 
         [0025]    The lightweight material  106  depicted in  FIG. 1  is of substantially similar length and width of the enclosed area created by the first core frame  109  and the second core frame  117 . The lightweight material  106  is of substantially similar thickness as the combined thickness of the first core frame  109  and the second core frame  117 . In another embodiment, the lightweight material would be equal in thickness to a plurality of first core frames  109 , or the thickness of a single first core frame  109 . The lightweight material  106  is therefore shaped so as to occupy the cavity that would otherwise be created when the top skin panel  102 , first core frame  109 , second core frame  117 , and bottom skin panel  104  are assembled. The lightweight material  106  may be formed from a polystyrene foam or any other material that is similar in density and rigidity to polystyrene and similarly rigid in nature. In one embodiment, the lightweight material  106  may be expanded polystyrene foam. 
         [0026]    Turning to  FIG. 2 , a depiction is presented of a perspective view of the assembled components of the lightweight composite panel  100  prior to being formed in a press  126 , in accordance with an embodiment of the present invention. The top skin panel  102  and the bottom skin panel  104  are positioned on the exterior of the lightweight composite panel  100 . In one embodiment, the components of the lightweight composite panel  100  are arranged such that the second core frame  117  is positioned atop the bottom skin panel  104 , the first core frame  109  is positioned atop the second core frame  117 , the lightweight material  106  is placed in the area enclosed by the bottom skin panel  104  and the first and second core frames  109   117 , and the top skin panel  102  is placed atop the first core frame  109  and lightweight material  106 . 
         [0027]      FIG. 3  depicts a cross-sectional view of the assembled components of the lightweight composite panel  100  prior to being formed in the press  126 . As the view depicted is a cross-sectional view, the second flat member  110  and fourth flat member  114  of the first core frame  109  are shown, and the second flat member  118  and fourth flat member  122  of the second core frame  117  are shown. The top skin panel  102  and the bottom skin panel  104  are also visible in  FIG. 3 . 
         [0028]      FIG. 4  is a cross-sectional exploded view of the components of a lightweight composite panel  100  positioned in a press, prior to forming, in accordance with an embodiment of the present invention. The press  126  comprises a mold base  130  and an upper mold half  128 .  FIG. 4  will be described in greater detail when the method of manufacturing the lightweight composite panel  100  is described in detail below. 
         [0029]      FIG. 5  is a perspective view of the lightweight composite panel  100 , after the forming operation has been performed in the press  126 , in accordance with an embodiment of the present invention. As can be seen in  FIG. 5 , the lightweight composite panel  100  takes the contour of the mold base  130  and upper mold half  128  after the forming operation in the press  126 . 
         [0030]      FIG. 6  is a section view of  FIG. 5 , according to an embodiment of the present invention. The contour of the lightweight composite panel  100  is readily apparent. As the view depicted is a cross-sectional view, the second flat member  110  and fourth flat member  114  of the first core frame  109  are shown, and the second flat member  118  and fourth flat member  122  of the second core frame  117  are shown. The top skin panel  102  and the bottom skin panel  104  are also visible in  FIG. 6 . 
         [0031]    The method of manufacturing the lightweight composite panel  100  will now be described, as performed in one embodiment of the invention. The method commences with the assembling of the first core frame  109  from the first flat member  108 , the second flat member  110 , the third flat member  112 , and the fourth flat member  114 . The flat members  108   110   112   114  comprising the first core frame  109  are fastened together by way of a fastening means  124 . The fastening means  124  may comprise a staple, an adhesive, a nail, a threaded fastener, or any other fastening means that is known to one skilled in the art to be suitable for the purpose. As described above, the first core frame  109  forms an enclosed area once assembled. 
         [0032]    In one embodiment of the invention, a second core frame  117  is assembled in the same fashion as the first core frame  109 . In other embodiments of the invention, there may be yet additional core frames assembled in a similar fashion as the first core frame  109 . In all embodiments of the invention that employ multiple core frames, the overall length and width of the respective core frames is substantially similar. 
         [0033]    In one embodiment of the invention that employs a single core frame, the method now progresses to the next step. However, in other embodiments of the invention that employ multiple core frames another step is performed. In such an embodiment, the multiple core frames are assembled atop each other and fastened together with a fastening means, thereby forming a single core frame. The fastening means may comprise staples, nail, threaded fasteners, adhesives, or any other fastening means that is known to one skilled in the art to be suitable for the purpose. 
         [0034]    A top skin panel  102  is formed in a length and width substantially similar to that of the first core frame  109 . The top skin panel  102  has an inner and outer surface, the inner surface being obscured from view once the lightweight composite panel  100  is assembled and the outer surface being viewable by the end user. A bottom skin panel  104  is formed in a length and width substantially similar to that of the first core frame  109 . The bottom skin panel  104  has an inner and outer surface, the inner surface being obscured from view once the lightweight composite panel  100  is assembled and the outer surface being viewable by the end user. The materials from which the top skin panel  102  and bottom skin panel  104  may be formed are discussed above. 
         [0035]    A lightweight material  106  is then formed in a shape of approximate equal length and width of the enclosed area created by the first core frame  109 . In an embodiment that employs only a first core frame  109 , the lightweight material is of approximate equal thickness of the first core frame  109 . In embodiments of the invention that employ the first core frame  109  and second core frame  117 , or additional core frames, the thickness of the lightweight material  106  is equal to the combined thickness of the multiple core frames. In an embodiment that employs only a first core frame  109 , the lightweight material  106  is then placed within the enclosed area of the first core frame  109 . In alternative embodiments of the invention that employ the first core frame  109  and second core frame  117 , or additional core frames, the lightweight material  106  is placed within the enclosed area of the multiple core frames. The lightweight material positioned within the enclosed area of the core frames then forms what will be referred to as a core frame and lightweight material assembly. The lightweight material assembly has a top and bottom side. 
         [0036]    An adhesive is applied to the top and bottom side of the core frame and lightweight material assembly. An adhesive is applied to the inner surface of the top skin panel  102  and the inner surface of the bottom skin panel  104 . In one embodiment of the invention, the adhesive applied may be of the type that is cured through the application of heat. In an alternative embodiment of the invention, the adhesive applied may be of the type that is cured through the application of electromagnetic energy. In embodiments of the invention that utilize an additional panel placed between the first core frame  109  and the top skin panel  102  or between the bottom skin panel  104  and second core frame  117 , adhesive may be applied on either side of the additional panel. In embodiments of the invention that makes use of an additional panel placed between the top skin panel  102  and the first core frame  109 , adhesive may not be applied to the top skin panel  102 . In other embodiments of the invention that utilize an additional panel placed between the bottom skin panel  104  and the second core frame  117 , adhesive may not be applied to the bottom skin panel  104 . In an alternative embodiment, a fastener means is used to fasten the top skin panel  102  and bottom skin panel  104  to the core frame and lightweight material assembly. The fastener means may comprise any suitable fastening means that is known to one skilled in the art to be suitable for the purpose. 
         [0037]    The core frame and lightweight material assembly is then positioned on top of the inner surface of the bottom skin panel  104 . The inner surface of the top skin panel  102  is then positioned on top of the core frame and lightweight material assembly. 
         [0038]    The bottom skin panel  104 , core frame and lightweight material assembly, and top skin panel  102  are then positioned in a press  126 . In one embodiment of the invention, the press  126  broadly includes a mold base  130  and an upper mold half  128 , along with a mechanical or hydraulic structure that presses the mold base  130  and upper mold half  128  together. The mold base  130  and upper mold half  128  have a curved contour about their longitudinal axis, with a substantially similar radius. The curved contour of the mold base  130  and upper mold half  128  is readily apparent in the embodiment of the invention depicted in  FIG. 4 . Although not depicted in  FIG. 4 , alternative embodiments of the invention may use a mold base  130  and upper mold half  128  that are shaped in a manner as to form the lightweight composite panel  100  in a compound curved shape. Additionally, the lightweight composite panel  100  could be formed in a substantially flat shape with the appropriately shaped mold base  130  and upper mold half  128 . The upper mold half  128  of the press  126  is then pressed down, towards the mold base  130  through the application of force in the same direction. This pressing operation presses the bottom skin panel  104 , core frame and lightweight material assembly, and top skin panel  102  into the mold base  130 , and forces them to be formed into a contoured shape substantially similar to that of the mold base  130  and upper mold half  128 . In alternative embodiments, the mold base  130  and upper mold half  128  may not have a curved contour, and instead may be substantially flat. As would be understood by those of skill in the art, other shapes and contours could also be formed with an appropriate mold. 
         [0039]    In embodiments that employ an adhesive cured through the application of heat, the pressing process may include the additional step of heating the components of the lightweight composite panel  100  in order to cure the adhesive. This may be accomplished through the heating of the press  126 , mold base  130 , or upper mold half  128  by various methods well known in the art. In embodiments that employ an adhesive cured through the application of electro magnetic energy the pressing process may include the additional steps of applying electro magnetic energy to the components of the lightweight composite panel  100  in order to cure the adhesive. This may be accomplished through various methods well known in the art. 
         [0040]    The present invention has been described in relation to particular embodiments, which are intended in all respects to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its scope. 
         [0041]    It will be seen from the foregoing that this invention is one well adapted to attain the ends and objects set forth above, and to attain other advantages, which are obvious and inherent in the device. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and within the scope of the claims. It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not limiting.