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TECHNICAL FIELD  
         [0001]    This invention relates to a curvilinear spa, and more particularly to curvilinear spa frame design to support a curvilinear spa shell.  
         BACKGROUND  
         [0002]    Typical spas are designed around dimensional lumber and are usually very linear in shape. Some deviations do occur in certain models but only on one or two sides. Spas with very linear shell shapes require very linear frames that are easily constructed with dimensional lumber, like 2×4&#39;s or 2×2 lumber.  
           [0003]    Typical linear spas are very plain looking, especially when the cover is on and they are not in use. Linear spas are not architecturally pleasing and cannot in and of themselves become a focal point for the customers&#39; landscape architecture. Accordingly, many spa owners hide their spas with landscaping or put them inside structures such as gazebos.  
           [0004]    It is therefore advantageous to provide the customer with a spa shell that is curvilinear in shape so that the spa is not just a box of hot water. A spa shell that has curvilinear sides necessarily requires a frame that among other things will remain square with handling and water pressure and that will fully support the bar top. Current linear spa frame designs are inadequate for a curvilinear spa shell design. A metal frame that follows the entire profile of the curvilinear spa is complex in shape and difficult to manufacture. Additionally, such a frame would be heavy. As a result, the cost associated with such a frame would be excessive.  
         SUMMARY  
         [0005]    The present curvilinear spa frame invention addresses the need to provide a rigid frame to support a curvilinear spa shell design. The present invention includes a frame comprised of a bottom plate of shaped plywood or similar support material, to which can support a multiplicity of box sections aligned to be within the confines of the spa shell curves and provide stiffness for the completed frame in all directions. Atop these box sections would be affixed a multiplicity of curved pieces that form the top rail of the frame and support the spa bar top. The box sections can be given greater rigidity by the use of truss plates and associated assembly, by the use of sheet material as a stiffener or by any other fasteners.  
           [0006]    In another embodiment of the present invention, sheet material can be used in conjunction with corresponding notches in the curved components to align the top and bottom of the frame.  
           [0007]    The present invention provides a frame that will remain square regardless of handling and water pressure while fully supporting the bar top of the spa. It is another advantage of the present invention to fully support a curvilinear spa shell design without complicated frame components that can mimic the curvilinear shape of the bar top. It is yet another advantage of the present invention to have a frame support a curvilinear spa shell design by use of structural box elements that are not as complex in shape as the outline of the curvilinear spa shell. Another advantage of the present invention includes structural box frames that need not follow the entire circumference of the curvilinear spa outline. It is yet another advantage of the present invention that the frame components are easier to manufacture. It is another advantage of the present invention that interlocking sheet material and groove techniques or other known techniques can be utilized to make alignment of the curvilinear spa frame components easier resulting in rapid and reliable assembly and a stronger, more rigid frame. It is yet another advantage of the present invention that the bar top be supported adequately by the curvilinear top rail without necessarily requiring the use of non-standard lumber. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
       
    
    
     DESCRIPTION OF DRAWINGS  
       [0008]    [0008]FIG. 1 is an isometric view of a curvilinear spa.  
         [0009]    [0009]FIG. 2 is an isometric view of a curvilinear spa frame.  
         [0010]    [0010]FIG. 3 is a top view of the top rail of the spa frame.  
         [0011]    [0011]FIG. 4A is an isometric view of another embodiment of the curvilinear spa  
         [0012]    [0012]FIG. 4B is an isometric view of a box section with panel and interlocking groove.  
         [0013]    [0013]FIG. 5 is a box section with truss. 
     
    
       [0014]    Like reference symbols in the various drawings indicate like elements.  
       DETAILED DESCRIPTION  
       [0015]    [0015]FIG. 1 depicts an embodiment of a curvilinear spa  2 . Curvilinear spa  2  has an inner shell  4  that can hold water and includes support for spa users while experiencing the benefits of hydrotherapy. Bar top  6  substantially follows the contour of the curvilinear spa outline formed in part by the decorative siding  22 .  
         [0016]    [0016]FIG. 2 depicts a curvilinear spa frame  8  that supports the curvilinear spa shell  4 . As depicted in FIG. 2, the curvilinear spa frame  8  includes a top rail  10  and a bottom rail  12 . The top rail  10  and bottom rail  12  substantially mimics the contour of the curvilinear spa  2 . The top rail  10  and bottom rail  12  can be made of any material suitable for supporting the weight associated with the use of the shell  4 , for example, wood, metal, composite materials like fiberglass, etc. The top rail  10  can be substantially the same shape as the bar top  6  and can support the weight associated with the bar top  6 . During assembly, the top rail  10  can be aligned with and become an anchor for the bar top  6 .  
         [0017]    As depicted in FIG. 2, the bottom rail  12  can be supported by a bottom pedestal  14  or similar support structure. The bottom pedestal  14  is used to give additional stability to the frame and like the top and bottom rail, can be made of any material capable of supporting the weight of the spa, like wood, metal, composite materials like fiberglass, etc. For additional rigidity, bottom beam  16  can be secured to the opposing sides of the bottom pedestal  14 . Other similar fastening techniques can be utilized as well to secure the bottom rail  12 , top rail  10  and bottom pedestal  14  in a predetermined manner in order to facilitate assembly and rigidity.  
         [0018]    As shown in FIG. 2, between top rail  10  and bottom rail  12  is a plurality of box sections  18 . Box sections  18  provide rigidity to the frame structure in addition to providing support to the top rail  10 . Box sections  18  are substantially linear and can be spaced intermittently substantially within the confines of the outer diameter of the curvilinear frame  8  thereby alleviating the need for more complex shaped support structures that follow the complex contours of the curvilinear spa frame  8 . Box sections  18  can be prefabricated and made of any material capable of supporting the weight associated with the spa  2 , like metal, wood, composite materials like fiberglass, etc.  
         [0019]    [0019]FIG. 3 depicts a top view of the top rail  10 . Top rail  10  can be formed as one piece, or alternately, can be formed from a multiplicity of pieces, e.g., fabricated using a CNC machine. When the pieces are fastened, the top rail  10  is formed and becomes a structurally sound support member for the bar top  6  (not shown). If a multiplicity of overlapping pieces are utilized to fabricate top rail  10 , glue, staples, or other known fasteners can be used to create an integrated top rail  10  member.  
         [0020]    [0020]FIGS. 4A and B depicts another embodiment of the curvilinear spa frame  8  that is easy to assemble and sufficiently rigid. As seen in FIG. 4A, the box sections  18  include a sheet  24  fastened in any known fashion to a rectangular structural member  26 . As depicted in FIG. 4B, use of the sheet  24  not only improves rigidity, but also assists with alignment of curvilinear spa frame components, e.g., the top rail  10  and bottom rail  12 . As depicted in FIG. 4B, the sheet  24  interlocks into notches in the top rail  10  and bottom rail  12 . As a result, box section  18  can be readily inserted into the appropriate position between top rail  10  and bottom rail  12  thereby facilitating alignment of the top rail  10  and bottom rail  12 . The notches can be located in various combinations of the top rail  10  and bottom rail  12 , as long as the box section  18  assists alignment of the spa frame curvilinear components, e.g., the top rail  10  to the curvilinear bottom rail  12 . Other fastening techniques can be utilized, e.g., predetermined placement of holes in the top and bottom rails with associated pegs on the top and bottom of the box section  12  (not shown). Additionally, strategic use of any modern fasteners, e.g., predetermined placement of pieces of sheet metal also may be used to ensure that corresponding box sections  18  are secured at corresponding predetermined locations in the curvilinear spa frame during assembly, thereby facilitating alignment of the curvilinear spa frame components. Those of skill in the art will appreciate the fact that many different types of interlocking construction can be utilized, e.g., pegs and holes, interlocking sheet material and notches, etc. The interlocking construction can be located on any and/or all curvilinear frame components to improve rigidity and increase ease of assembly. As depicted in FIG. 4A, additional supports  28 , in this case 2×2s, can be included in the curvilinear spa frame  8  as needed to increase rigidity.  
         [0021]    To further increase structural rigidity, FIG. 5 depicts the use of truss plates  20  on box section  18 . If more rigidity is desired, additional truss plates  20  can be added. Typically, truss plates are made of sheets of galvanized steel and are secured into the box sections using pressure during fabrication.  
         [0022]    Moreover, increasing the strength of the box sections  18  may advantageously reduce the number of box sections  18  required to maintain the rigidity associated with the spa  2 . To further reduce the number of box sections  18  required, additional supports  28  as depicted in FIG. 4A can be added.  
         [0023]    A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, additional structural members may be added to the curvilinear spa frame  8  to increase rigidity. Moreover, various fastener and bracing technologies can be incorporated into the curvilinear spa frame design, e.g., hangers and plates, angle braces and gussets to brace the fame along various axis, framing connectors, spacers, etc. Such components can be located, for example, between the box sections and the top rail  10 , or alternately between the box sections  18  and bottom rail  12  without departing from the spirit of the invention. Additionally, those of skill in the art will appreciate that depending on the size, shape and strength of each box section, more or less box sections  18  can be included into the curvilinear spa frame than discussed or depicted. Furthermore, box sections can be many shapes and sizes and can have a variety of interlocking mechanisms located on various sections of the spa frame, not just the top rail  10  and/or bottom rail  12 . Accordingly, other embodiments are within the scope of the following claims.

Summary:
A curvilinear spa frame apparatus and method that provides support to a curvilinear spa shell design, including a frame comprising a top curvilinear rail, a bottom curvilinear rail, and one or more box sections aligned to be within the confines of the curvilinear spa shell providing stiffness for the completed frame. The box sections can include sheets that align with corresponding notches in the curvilinear spa frame increasing rigidity and facilitating alignment of the spa frame components during assembly.