Abstract:
A lightweight concrete reinforcing panel with face sheet reinforcement is provided having a face sheet and a frame with reinforcing members. The reinforcing members preferably extend between opposed rails of the frame and have openings therethrough with braces extending transversely to the axis ofthe reinforcing members. The braces may be provided by cutting and bending the reinforcing member to form flanges and the openings, and may alternate on either side of the reinforcing member, or alternatively may be separate, discrete bracing elements which pass through the openings. Thus positioned, the bracing elements may pivot on the reinforcing member to flex with the face sheet. The bracing elements may be linear, such as bars, loops, or other shapes to spread the load applied to the front side of the face sheet.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention concerns a concrete forming panel used as a temporary forming material for the application of fluid cementations material thereagainst to provide for its form after hardening. More particularly, it is concerned with a concrete forming panel which includes a reinforcement for the face sheet which reduces the overall weight of the panel by the configuration and placement of the reinforcement.  
           [0003]    2. Description of the Prior Art  
           [0004]    Concrete is typically poured into forms which permit the concrete to set in a desired shape or configuration. The forms are then removed, leaving the solidified concrete to form a structural member, such as a wall or the like. In small construction jobs, plywood may be used as the form and supported by wood studs until the concrete hardens into the desired shape. Such forming practices are well known but not particularly economical when a builder must repeatedly form similar walls during a series of construction projects.  
           [0005]    For this reason, reusable concrete forming panels of metal have been developed which may be positioned and held together to provide a concrete forming wall with a central cavity. Such known forming panels include those shown in, for example, U.S. Pat. Nos. 4,708,315, 4,958,800, 5,058,855, 5,184,439, and 5,965,053, the disclosures of which are incorporated herein by reference. Aluminum forming panel systems provide faster construction set up than standard steel and plywood systems, are lighter in weight, and typically leave a smooth wall surface which is better looking than other construction form systems.  
           [0006]    Such aluminum forming panels must be relatively rigid and of sufficient strength to resist deformation due to the weight of the concrete bearing against the face sheet. Existing aluminum forming panels employ a frame and a face sheet which utilize a number of channels in the form of generally unshaped “hats” and stiffeners to minimize the bending or other deformation of the face sheet. However, such channels and stiffners have heretofore added significant weight to the forms, and moreover have provided reinforcement along only substantially linear stretches across and along the back of the face sheet. While effective, the necessary material adds expense and weight to the forming panel, making handling more difficult.  
           [0007]    There has thus developed a need for a forming panel useful in many environments which includes is lighter in weight but remains relatively stiff while more efficiently using material in the face sheet stiffening members than past forming panels.  
         SUMMARY OF THE INVENTION  
         [0008]    These objects have largely been achieved by the lightweight concrete forming panels with face sheet reinforcement in accordance with the present invention. That is to say, the present invention permits the use of reusable metal forming panels with a more efficient use of the face sheet stiffening members than those of the prior art, and which more effectively distributes the loads placed on the face sheet. By providing reinforcing members which distribute the load transversely to the longitudinal axis of the reinforcement members, more efficient use of material and more effective face sheet reinforcement may be achieved.  
           [0009]    In greater detail, the forming panels of the present invention include a frame and a face sheet, both preferably primarily of aluminum. As used herein, “aluminum” is intended to refer to both elemental aluminum and alloys wherein the primary constituent is aluminum. The face sheet is a relatively thin sheet of aluminum, and the frame includes at least one rail and at least one reinforcing member extending across the back side of the face sheet. The reinforcing member is elongated having a longitudinal axis and is advantageously provided with braces extending transversely therefrom. The braces are either formed from the reinforcing member by cutting and bending the reinforcing member, or alternatively by separate braces of metal, preferably aluminum, extending transversely from the longitudinal axis. Such separate braces include both linear members such as bars, or alternatively arcuate or polygonal shaped braces which are positioned to bear against the reinforcing members. The reinforcing members have openings to permit such separate braces to pass therethrough, the reinforcing members acting as a fulcrum to permit limited pivoting movement of the braces. Such movement is helpful to allow limited flexing of the face sheet as poured concrete rises against the opposite side of the face sheet 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is a fragmentary, rear perspective view of a forming panel of the present invention showing the face sheet and the frame with reinforcing members having a plurality of openings therealong and alternating flanges formed from the material bent to provide the openings;  
         [0011]    [0011]FIG. 2 is an enlarged, fragmentary vertical cross-sectional view taken along line  2 - 2  of FIG. 1 showing a T-shaped reinforcing member with alternating flanges welded to the back side of the face sheet;  
         [0012]    [0012]FIG. 3 is an enlarged, fragmentary horizontal cross-sectional view taken along line  3 - 3  of FIG. 2 showing the configuration of the openings formed by bending the flanges;  
         [0013]    [0013]FIG. 4 is a fragmentary, rear perspective view of an alternate embodiment of the forming panel of the present invention, showing reinforcing members having bracing elements with flanges extending both vertically and horizontally across the back side of the face sheet;  
         [0014]    [0014]FIG. 5 is an enlarged, fragmentary vertical cross-sectional view taken along line  5 - 5  of FIG. 4 showing the arrangement of the bracing elements on the intersecting reinforcing members;  
         [0015]    [0015]FIG. 6 is an enlarged, fragmentary horizontal cross-sectional view taken along line  6 - 6  of FIG. 4 showing the arrangement of the bracing elements on the intersecting reinforcing member;  
         [0016]    [0016]FIG. 7 is an fragmentary, rear perspective view of a second alternate embodiment of a forming panel in accordance with the present invention, wherein the bracing elements are provided as loops passing through openings of the reinforcing members;  
         [0017]    [0017]FIG. 8 is an enlarged, fragmentary horizontal cross-sectional view taken along line  8 - 8  of FIG. 7 showing the attachment of the bracing elements to the reinforcing members extending across the back side of the face sheet;  
         [0018]    [0018]FIG. 9 is an enlarged, fragmentary rear elevational view showing the bracing elements of FIG. 7 attached by welding beads to the back side of the face sheet and the reinforcing members;  
         [0019]    [0019]FIG. 10 is a rear perspective view of a third embodiment of the forming panel of the present invention including bracing elements provided as elongated bars extending transversely to and passing through openings of the reinforcing members, the bars being held by the end rails. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0020]    Referring now to the drawing, a lightweight concrete forming panel  10  in accordance with the present invention broadly includes a face sheet  12  and a frame  14 . The face sheet is relatively thin, usually between about 0.090 and 0.125 inches in thickness, and includes a front side  16  against which concrete is poured for forming and hardening and a back side  18 . The frame  14  includes at least one rail, as where the frame is circular, oval or otherwise of a continuous arcuate shape, but more typically includes a pair of elongated, parallel, spaced-apart side rails  20  and  22 , and a pair of elongated, parallel, spaced-apart end rails  24  and  26  (as best seen in FIG. 10) which are joined together at their respective ends by welding or mechanical fasteners to form the shape of a polygonal, typically rectangular, frame  14  as shown in the drawings. The face sheet  12  is of a shape complemental to and attached with the back side  18  of the face sheet  12  welded or otherwise secured to the front edges of the rails. The frame  14 , and both the face sheet and the frame are preferably provided of metal. One example of the primary material used in the metal forming panel  10  hereof is aluminum and its alloys, such as ASTM 6061 T-6 aluminum. The frame  14  further includes reinforcing members  28  which extend across the back side  18  of the face sheet to provide a degree of rigidity and prevent deformation of the face sheet  12 .  
         [0021]    In greater detail, the side rails  20  and  22  and the end rails  24  and  26  are cast or extruded into elongated members which have relatively little material included therein, such as extruded members with hollow channels or solid members of about the same thickness as the face sheet, they may be provided with a front edge  30  and a bend  32  proximate the rear edge  34 . The bend  32  helps to resist deformation due to impact and loads placed on the face sheet and the rails. The bend  32 , or similarly openings in a hollow rail, also enable the rails to help retain the reinforcing members  28  in position.  
         [0022]    The reinforcing members  28  are preferably elongated to span the distance between spaced-apart rails and have a first leg  34  which extends generally perpendicular to the face sheet  12  and a second leg  36  angularly oriented relative to the first leg. A plurality of reinforcing members  28  may be provided, preferably in spaced relationship as shown in FIGS. 1, 4,  7  and  10 . The reinforcing members may be generally positioned to extend between the side rails  20  and  22 , but may also be oriented in intersecting relationship as shown in FIG. 4 so that they may extend alternatively, or only, in a generally perpendicular orientation to the end rails  24  and  26 . The second leg  36  is preferably substantially parallel to the face sheet  12  whereby the reinforcing member  28  is generally T-shaped or L-shaped in cross-section. The first leg  34  has a front edge  38  which engages or lies immediately proximate the back side  18  of the face sheet  12 , and may be welded thereto or alternatively not fastened to the back side  18 . The first leg  26  includes a plurality of openings  40  spaced across its length, as shown in FIGS. 1, 3,  4 ,  5 ,  6 ,  7 ,  8 ,  9  and  10 . The openings  40  are positioned at the front edge  38  of the first leg  36 .  
         [0023]    A plurality of braces  42  extend transversely to the longitudinal axis of the first leg  34  of the reinforcing members  28  and are positioned adjacent the openings  40 . The braces  42  may include flanges  44  and  46  which are formed by cutting the first leg  34  to provide the openings  40 . The flanges  44  are oriented to extend opposite the flanges  46  and alternate therewith, so that good load distribution is provided against the reinforcing members  28  on both sides of the first leg  34 . Thus, the flanges provide for improved load distribution relative to the substantially linear force concentrations along the front edge  38  of the first leg  34 . The flanges  44  and  46  extend only a portion of the distance between adjacent spaced-apart reinforcing members to provide force distribution without weakening the reinforcing members along the front edge  38  and maintaining the desired goal of lightness in weight.  
         [0024]    As shown in FIGS. 4 through 6, transverse reinforcing members  48  may be provided especially adjacent the end rails  24  and  26  to provide additional reinforcement and strengthening. The transverse reinforcing members are configured similarly to the reinforcing members  28  and include a first leg  34   a  and a second leg  36   a  and present openings  40   a  therealong. This configuration is especially beneficial with forms having longer end rails as the load—essentially the hydraulic head caused by the weight of the fluid concrete—may be greater at the lower end of an upright forming panel  12  or when two or more forming panels  10  are stacked. In this configuration, the flanges  44  and  46  of the reinforcing members  28  extend toward the end rails, and the flanges  44   a  and  46   a  of the transverse reinforcing members  48  extend toward the side rails.  
         [0025]    [0025]FIGS. 7 through 9 illustrate an additional embodiment of the forming panel  10  wherein the braces  42  include loops  50  passing through the openings  40  and positioned by the flanges  44  and  46  of the reinforcing members  28 . The loops may be welded to the back side  18  of the face sheet  12  by beads  52  or welded to the flanges  44  and  46 , or both. The loops  50  further extend the area of force distribution transferred from the face sheet  12  to the reinforcing member  28 . Beneficially, the passage of the loops  50  through the openings  40  cause the first leg  34  to act as a fulcrum about which the loops  50  may have limited pivoting. This pivoting action may help to allow the face sheet  12  to flex as concrete is poured against the front side of the face sheet  12  and thereby avoid stress concentrations as the concrete rises.  
         [0026]    [0026]FIG. 10 illustrates a further embodiment of the forming panel  10  of the present invention, wherein the braces  42  include elongated bars  54  which are substantially perpendicular to the longitudinal axis ofthe reinforcing members and pass through the openings  40  in the reinforcing members. The bars  54  may be welded to the reinforcing members  28 , the face sheet  12 , or both. Alternatively, the bars  54  may simply be received by the openings  40 , lie adjacent the back side  18  of the face sheet  12 , and held in place by the end rails  24  and  26 . The bends  32  of the rails are beneficial in that they cover the ends of the bars.  
         [0027]    In use, the forming panels  10  are coupled together in side by side relationship or at angles to one another to form corners, stacked atop on another to increase the possible height of the wall to be formed, and joined by tie bars to opposing forms so that concrete, to include all types of flowable cementatious material, may be poured therebetween. As the concrete rises during pouring, its weight increasingly bears against the front side  16  of the face sheet  18 . This weight might otherwise substantially bend and deform the relatively thin face sheet  12 , except for the reinforcing members which span the back side  18 . The reinforcing members  28  avoid stress concentrations along the front edge thereof which would create lines across the face sheet  12  and in the hardened concrete by the use of the braces  42 . The braces, which occupy only a limited area on the back side  18  of the face sheet  12 , help to maintain a more even force distribution and avoid deformation of the face sheet  12  without adding substantial weight to the forming panel  10 . Lightness in weight of the forming panel  10  arising from limiting the amount of material included therein not only makes it more economical to produce, but makes the forming panels  10  easier to handle and less expensive to ship. Thus, much of the strength of existing forming panels is achieved in forming panel that is lighter, less expensive and easier to handle.  
         [0028]    Although preferred forms of the invention have been described above, it is to be recognized that such disclosure is by way of illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments, as hereinabove set forth, could be readily made by those skilled in the art without departing from the spirit of the present invention.  
         [0029]    The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of their invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set out in the following claims.