Abstract:
An improved hollow beam suitable for construction of screened enclosures and the like, the beam being composed of a mated pair of generally C-shaped extruded members, preferably of identical configuration. Each extruded member comprises a side wall, a male flange member forming one of the short arms of the C-shape, and a female flange member forming the other of the short arms of the C-shape. The combination of the male and female flanges define a coupling assembly presenting a generally planar mated exterior surface on the end walls.

Description:
[0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/801,684, filed May 19, 2006. 
     
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates generally to the field of beams, typically composed of aluminum, used in the construction of screened enclosures or the like. More particularly, the invention relates to such beams that are rectangular in cross-section, often referred to as a box beam, and even more particularly, to such beams that formed by the joining or mating of two separately extruded members. 
         [0003]    In the construction of screened enclosures and similar structures, it is desirable to provide structural support elements, and especially horizontally disposed support elements such as beams, that are relatively lightweight but meet minimum rigidity and strength requirements when used to span relatively long distances. Such beams are often composed of extruded aluminum, since this metal is lightweight, strong, and inexpensive in relation to other suitable materials in terms of manufacture and transport. The beams are generally rectangular in cross-section and are formed primarily hollow to conserve weight. The beams are typically manufactured using metal extrusion processes, and it is known to construct the beams by joining two generally C-shaped in cross-section members, where the short legs or flanges of each member are provided with coupling structures which are received by or mate with the corresponding coupling structure when the two members are brought together to form the rectangular beam. 
         [0004]    It is an object of this invention to provide an improved structure for a beam composed of a pair of mated members. 
       SUMMARY OF THE INVENTION 
       [0005]    The invention is an improved hollow beam suitable for construction of screened enclosures and the like, the beam being composed of a mated pair of generally C-shaped extruded members, preferably of identical configuration. Each extruded member comprises a side wall, a male flange member forming one of the short arms of the C-shape, and a female flange member forming the other of the short arms of the C-shape. The combination of the male and female flanges define a coupling assembly and form the end walls of the beam, such that the two extruded members when aligned to create the generally rectangular beam are disposed in a mated condition whereby the end walls are comprised of the overlapping male and female flanges. Mechanical fasteners are provided to secure the male and female flange members to each other, thereby creating a box beam of high strength. 
         [0006]    The beam presents end walls having a planar exterior matting surface formed by the abutting outer surfaces of the male and female flange members. The exterior mating surface comprises the majority of the exterior of the end walls, the remainder portion comprising a pair of spline receiving channels that are used to secure screen panels to the beams in known manner. In an alternative embodiment, the female flange comprises a clip member having a resilient internal flange and a guide lip, such that proper alignment of the two extruded members is easily accomplished. Retention means comprising for example a series of ridges and channels are provided to mechanically interlock the two extruded members in the mated condition prior to insertion of eh mechanical fasteners. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is an end view of one embodiment of the beam. 
           [0008]      FIG. 2  is an end view of a C-shaped extruded member of the embodiment shown in  FIG. 1 . 
           [0009]      FIG. 3  is a partial end view of the tongue member of the male flange member of the embodiment shown in  FIG. 1 . 
           [0010]      FIG. 4  is a partial end view of the clip member of the female flange member of the embodiment shown in  FIG. 1 . 
           [0011]      FIG. 5  is an end view of another embodiment of the beam. 
           [0012]      FIG. 6  is an end view of the male flange member of the embodiment shown in  FIG. 5 . 
           [0013]      FIG. 7  is an end view of the female flange member of the embodiment shown in  FIG. 5 . 
           [0014]      FIG. 8  is a cross-sectional view of the upper portion of an alternative embodiment of the beam. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    With reference to the drawings, the invention will now be defined with regard for the best mode and the preferred embodiment. In general, the invention is a hollow, generally rectangular structural beam formed by the mating of two generally C-shaped extruded members. The extruded members forming the box beam are identical and are designed such that one extruded member will mate with another extruded member in a structurally supportive and generally secure manner by inverting one of the two extruded members and mating them together. The majority of the uppermost surface of the box beam is planar. 
         [0016]    One embodiment of the invention is shown best in  FIGS. 1 and 2 , wherein the beam  10  comprises a pair of generally C-shaped extruded members  20 , each extruded member  20  being longitudinally extended. The extruded members  20  each comprise a generally planar side wall  21  and a pair of flange members extending perpendicularly from the side wall  21  to define the short arms of the C-shaped configuration, one being a male flange member  22  and the other being a female flange member  23 . The flange members  22  and  23  extend the length of the beam  10 . The combination of the extruded members  20 , wherein one extruded member  20  is inverted or reversed and pressed against the other extruded member  20 , defines a hollow interior  12  and an end wall  13  with a mated exterior surface  11 , the mated exterior surface  11  being generally planar and extending across the majority of the end wall  13 . A coupling assembly  30  defined by combined structure in the male flange member  22  and the female flange member  23  retains the two extruded members  20  in the mated position. Mechanical fastening elements  37 , such as sheet metal screws, are utilized to further secure the two extruded members  20  in the mated position. Preferably, the extruded members  20  are configured identically, but it is possible that the may differ in certain respects without deviating from the invention as defined and claimed herein. 
         [0017]    As best shown in  FIG. 4 , the female flange member  23  of this embodiment comprises a clip member  31  that receives the tongue member  41  of the male flange member  22 . The clip member  31  comprises an external flange  11  that is relatively rigid in comparison to a resilient internal flange  33 . Internal flange  33  is preferably provided with a longitudinally extensive flex ridge or spring member  35  such that the internal flange  33  can be easily biased outwardly when the tongue member  41  is inserted into the clip member  31 , but which imparts a compressive force against the tongue member  41  after it is properly positioned and aligned within the clip member  31 . Most preferably a longitudinally extensive guide lip  34  is disposed on the free end of the internal flange  3 , such that initial alignment of the two extruded members  20  is more easily accomplished. The female flange member  23  is also provided with a longitudinally extensive recessed shoulder  36 , which corresponds to a longitudinally extensive lip  43  and channel  44  disposed on the male flange member  23 , such that when the two extruded members  20  are mated, a generally planar mated exterior surface  11  is presented. 
         [0018]    The male flange member  22  of this embodiment comprises a longitudinally extensive tongue member  41  of relatively thin cross-section, the tongue member  41  being sized and configured to be received by the clip member  31  in a snug and secure fashion. A longitudinal spur member  42  is disposed on the exterior of male flange member  22  at the base of the tongue member  41 , the spur member  42  comprising a lip  43  and a channel  44  configured to mate with the recessed shoulder  36  of the female flange member  23 . 
         [0019]    While the biasing force of the internal flange  33  of the clip member  31  pressing the tongue member  41  against the external flange  32  serves to retain the two extruded members  20  in the mated condition, it is preferable to provide additional retention means  50  in support of this. For example as shown, the retention means  50  to impede separation may comprise a series of ridges  51  and channels  52  disposed on the contiguous surfaces of the tongue member  41  and external flange  32 . 
         [0020]    The extruded members  20  preferably further comprise spline receiving channels  25  and internal reinforcing members  24 . An external fastener alignment channel  26  may also be provided on the exterior of the external flange  32  to assist in the placement of mechanical fasteners  37 . With this construction, the beam  10  presents end walls  13  having a planar, mated exterior surface  11  formed by the combination of the exterior surfaces of the male flange member  22  and the female flange member  23  that extends across and along the majority of the end wall  13 . The mated exterior surface  11  extends farther outward than the edges  27  of the side walls  21 , such that the distance between opposing mated exterior surfaces  11  is greater than the distance between opposing edges  27  on each side wall  21 . This feature provides for a better aesthetic presentation and securer footing for installers during the assembly process, since a planar surface is present and any screen material attached to the beam  10  sits flush with the mated exterior surface  11  due to the reduced height of the edges  27 . 
         [0021]    An alternative embodiment for the beam  10  is illustrated in  FIGS. 5 through 7 . In this embodiment the coupling assembly  30  comprises a male flange member  22 , shown in  FIG. 6 , and a female flange member  23 , shown in  FIG. 7  having a less complex configuration. The male flange member  22  comprises a projection member  61  offset from the planar outer surface  63  in a manner defining an outer shoulder member  62 . Male flange member  22  further comprises a recessed, generally planar inner surface  64  bounded by an inner shoulder  65 . The female flange member  23  comprises backing support member  71  having a generally planar abutting surface  72  that corresponds in configuration to the planar inner surface  64  of the male flange member  22 , the abutting surface being bounded by a longitudinally extending mating channel  73  defined by a longitudinally extending lip member  74 . The abutting surface  72  is offset from the generally planar outer surface  75 . As shown in  FIG. 5 , with one C-shaped extruded member  20  reversed, the corresponding male flange members  22  and female flange members  23  mate to define the generally rectangular box beam  10 . The projection member  61  of the male flange member  22  is received by the mating channel  73  of the female flange member  23  such that the planar abutting surface  72  of the female flange member abuts and supports the planar inner surface  64  of the male flange member  22 . The planar outer surface  63  of the male flange member  22  and the planar outer surface  75  of the female flange member  23  together define a planar mated exterior surface  11  across and between the side walls  21  and longitudinally along the majority of the outside of end wall  13 . The edges  27  of each side wall  21  are spaced at a distance less than the distance between the opposing mated exterior surfaces  11 , such that the outer surface of attached screen material will be flush with the mated exterior surface  11 . In other words, the mated exterior surfaces  11  are the outermost components of each of the end walls  13  excluding the mechanical fasteners. 
         [0022]    Still another alternative embodiment is illustrated in  FIG. 8 . In this embodiment, the male flange member  22  and the female flange member  23  are thicker. This embodiment provides extra rigidity against buckling for beams  10  with taller side walls  21 . 
         [0023]    It is understood and contemplated that equivalents and substitutions for some elements set forth above may be obvious to those skilled in the art, and with the intent of not being limited to the embodiments presented above as examples, the true scope and definition of the invention is to be as set forth in the following claims.