Abstract:
Concrete forming panels according to the present invention are formed using a series of interlocking panel sections mechanically connected at a forward face of the panel. The mechanical connection uses a hook portion of one section received in a slot portion of an adjacent section with a pivot and stop relation defining the planar forming face. A series of brace members extend across the panel sections on a rear surface and maintain engagement of the panel sections and reinforce the panel sections against deformation of the forming face during use of the panel. The arrangement is economical to manufacture in many different sizes as may be required by a customer. Some welding is used, however the mechanical connection greatly reduces the amount of welding required. Replacement sections can easily be used to repair damaged panels.

Description:
FIELD OF THE INVENTION 
     The present invention relates to concrete forming panels, and in particular, relates to concrete forming panels having a series of interlocking panel sections mechanically secured to adjacent panel sections. 
     BACKGROUND OF THE INVENTION 
     Concrete forming panels are commonly used in the construction industry to quickly assemble a concrete form. Forming panels have been used for many years, and often have a plywood concrete engaging face with a reinforcing structure secured on a rear side thereof to support the concrete load. 
     It is also known to use a concrete forming panel fabricated from aluminum extrusions where these extrusions are mechanically connected to define the forming panel. One such example of this structure is illustrated in Canadian Patent 2,141,463 that is owned by the present applicant. In this reference, the concrete forming panel is broken into a number of panel sections where each section is an aluminum extrusion. The aluminum extrusions are connected to an adjacent extrusion by a hook and slot arrangement, and by a curved flange provided adjacent a rear edge beneath the hook and slot arrangement. This curved flange is connected to a structural member of the adjacent panel section to mechanically secure the two sections together and to maintain a predetermined angle of the forward face of each of these panels. With this arrangement, a reinforced box-like structure is provided beneath the mechanical securement (hook and slot) of the two panels at the forward face. 
     With the structure as disclosed in Canadian Patent 2,141,463 the connected panel sections required additional support and the panel sections were prone to deflection at intermediary positions, even if the rear face of the panel was supported. 
     It would be desirable to provide a concrete forming panel having the desirable characteristic of being assembled from a series of extrusions while providing a panel that is easy to assemble and is relatively stiff. 
     SUMMARY OF THE INVENTION 
     A concrete forming panel according to the present invention comprises at least first and second interlocking panel sections having a mechanical hinge connection joining the sections at an intermediate position extending in the length of the forming panel. The mechanical connection comprises a hook portion on the first panel received in a slot portion of a second panel and the mechanical connection includes a stop abutment of the hinge connection that is engaged when the panel sections are joined and aligned to form the forming face of the panel. The panel includes a series of brace members extending across the panel section on a rear surface thereof. Each brace member maintains engagement of any stop abutments and provides a rear support of the mechanical connection opposing deflection of the forming face towards the brace member. 
     In an aspect of the invention, the second panel below the slot includes a downwardly extending web member having a distal end thereof in engagement with the series of brace members to provide the rear support of the mechanical connection. 
     In a further aspect of the invention, the downwardly extending web member includes a flange or bead portion at the distal end in engagement with the series of braces. 
     In a further aspect of the invention, the panel includes on either side of the length thereof, downwardly extending side rails and each of the series of brace members extend between and are secured to the side rails. 
     In a further aspect of the invention, the side rails include an inwardly extending flange portion, and the inwardly extending flange portion supports the brace members at opposite ends thereof. 
     In a further aspect of the invention, the brace members have an interference fit between said side rails and any of the flange or bead portions maintaining the panel in an assembled configuration. 
     In a preferred aspect of the invention, the forming panel includes at least a third panel section connected as an intermediary between the first and second panel sections. 
     In yet a further aspect of the invention, a pair of end rails close opposed ends of the concrete forming panel and are secured to the at least two panel sections. 
     In yet a further aspect of the invention, the brace members are tubular extrusion members fixedly secured to the side rails. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments of the invention are shown in the drawings, wherein: 
         FIG. 1  is a rear perspective view of the concrete forming panel; 
         FIG. 2  is an exploded perspective view of the concrete forming panel shown in  FIG. 1 ; 
         FIG. 3  is a partial exploded assembly view of a concrete forming panel having two panel sections; 
         FIG. 4  is a view similar to  FIG. 3  with the concrete forming panel in the assembled condition; 
         FIGS. 5 ,  6  and  7  show details of the particular mechanical hinge and the stop abutment that allows the panel to form a planar front face as shown in  FIG. 7 ; 
         FIG. 8  is a view of a concrete forming panel having first and second outer panel sections and an intermediary panel section; and 
         FIG. 9  is the panel of  FIG. 8 , but in an assembled form. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The concrete forming panel  2  shown in  FIGS. 1 and 2  includes three panel sections; namely side panel section  4 , intermediary panel section  8  and side panel section  6 . In the embodiment shown, the intermediary panel  8  includes a slot  46  adjacent one edge thereof for receiving the hook  40  of the side panel section  6 . The opposite edge of intermediary panel section  8  includes a hook  40  that is received within the slot  46  of the side panel section  4 . Details of the hook and slot and their mechanical connection are shown in  FIGS. 3 and 4 . 
     The concrete forming panel  2 , when the various panel sections are interconnected, has a series of brace members  16 ,  18  and  20  that engage a rear face of the panel sections and also extend between the side panel sections  4  and  6 . These brace members have a slight interference fit with the connected panel sections and the braces maintain the mechanical connections at the front face of the panel in locked engagement and maintain alignment of the panel section to define the planar front face of the forming panel. 
     The side panel sections  4  and  6  as shown in  FIGS. 1 and 2  include integral side edges  4   a  and  6   a  that define the sides of the panel and extend in the length of the panel. The ends of the panel are closed by the end rails  10  and  12 . The concrete forming panel  2  includes a plurality of connecting ports  30  provided in the sides of the panel to allow connection to adjacent panels. Preferably these connecting ports include a reinforcing insert to reduce wear of the ports due to fasteners. 
     As shown in  FIG. 3 , the hook  42  is received in the slot  46  and this generally requires it to be moved to the angular position as shown in  FIG. 5 . In this position, the hook is easily received within the slot  46  and will generally be supported by the upper lip  48 , being in other words a stop abutment, at one edge of the side panel  4 . The side panel  6  is rotated in a clockwise direction to the planar configuration of the panel as shown in  FIG. 7 . The side panel section  6  and the side panel section  4  have now aligned and form the planar front face of the concrete forming panel  2 . 
     Beneath the slot  46 , the extrusion includes a downwardly extending web member  52  that terminates in a bottom flange or bead portion  54 . This web and bottom flange support the slot  46  and, when engaged with the bracing member  18 , oppose downward deflection of the top surface of the panel  4  form a stiff load transmitting structure having a top flange, a connecting web and a bottom flange. This can be appreciated from a review of  FIG. 4 . 
     This particular support of the side panel section  4  supports the free end of this panel section and also supports the hook  40  of the side panel section  6 . In the embodiment of  FIGS. 3 through 7 , the concrete forming panel has only the two side panel sections  4  and  6  and the one intermediary support provided by the web  52  and the bottom flange or bead  54  is sufficient. 
     In the embodiment shown in  FIGS. 8 and 9 , an additional intermediary panel  8  has been provided having a similar slot  46  adjacent one edge thereof and a hook  42  provided at the opposite longitudinal edge. In this case, the intermediary panel section  8  also includes a central support generally shown as  60  which includes the downwardly extending web  62  and the lower flange or bead portion  64 . At the edge of the intermediary panel section  8  is the similar web  52  and lower flange  54  for supporting of the slot  46 . 
     From a review of the assembled panel of  FIG. 9 , it can be seen that each hook and slot arrangement is directly supported by a downwardly extending web  52  and a flange  54 . These members, in combination with the structure for forming of the slot  46 , form an I-beam type structure that provides excellent support for the mechanical connection. The intermediary panel section  8  includes the additional support  60  which also engages the bracing member  18 . The mechanical connection of intermediary panel section  8  and side panel section  4   a  is also positively supported by a web  52  and a lower flange  54 . The modified side panel section  4   a  also includes a downwardly extending web  62  and a bottom flange  64 , that provides intermediary support between the side portion  76  and the location of the slot  46  at one edge of the modified panel section  4   a . With this arrangement, a series of downwardly extending webs and associated flanges engage the various bracing members  16 ,  18  and  20  as shown in  FIGS. 1 and 2 , and thus provide a stiff load-transmitting structure to oppose any downward deflection of the front face of the concrete forming panel  2 . 
     Additional braces can be added as required. The side panel sections  4 ,  4   a  and  6  as shown in the drawings have relatively stiff sides at the edges of the concrete forming panel, and the side members  76  and  80  shown in  FIG. 9  serve to retain and secure the bracing member  18 . The side member  76  includes an inwardly extending flange  78  that engages and provides support for the base of the bracing member  18 . Member  80  includes inwardly extending flange  82  that supports the opposite end of the bracing member  18 . Bracing member  18  can be forced into the gap at the rear of the panel and preferably has a slight interference fit with the remaining components to maintain the assembled concrete forming panel in a desired assembly for final securement. The bracing members  16 ,  18  and  20  are typically welded to the side rails of the panel, namely  76  and  78 , as shown in  FIG. 9 . This arrangement positively maintains the trapezoidal bracing members in the interior of the concrete forming panel at the open rear surface thereof. The end rails  10  and  12  are also preferably welded to the panel sections by a series of tack welds. 
     Other arrangements for securing of the panel sections to each other can be used, however the use of tack welding simplifies the manufacturing steps and also reduces the cost to manufacture the panel. As can be appreciated, the particular design of the concrete forming panel allows convenient assembly of the various components and these components can generally be maintained in their assembled condition in preparation for welding. The insertion of the bracing members maintains the panel sections in preparation for final securement. Typically the end rails are merely located at the ends of the extrusions and are tack welded in place. 
     The particular hook and slot arrangement does provide a positive stop face that limits angular movement of adjacent panels, and this stop face assists in defining the planar front face of the concrete forming panel. A very small seam may be visible at this stop face, however this seam is under compression and as such any joining line is quite thin. This improves the finished surface of the concrete. The use of aluminum extrusions also results in the concrete forming panel being easily separated from the concrete and a clean finished surface being defined. 
     When these concrete forming panels are in place and under load, they are connected to adjacent panels using the various ports  30 . Suitable collars can be inserted in the ports, and the panels can be assembled using steel-type connecting pins and wedges. The assembled panels can then be supported by further structural members provided behind the panels. When the panels are loaded due to the concrete load, this load tends to further tighten the mechanical joint and to tighten the securement of the panel sections. The braces positively support the rear surface of the forming face. With this arrangement, the seam at the junction of the hook and slot is under compression and the seam is quite small. 
     The particular arrangement shown and described allows a series of intermediary panels to be connected between the side panels, and thus panels of different widths are easily produced. The mechanical connection is basically the same, and the number of intermediary supports may be increased. Furthermore, it can be appreciated as shown with respect to the side panel section  4   a , these side panel sections can also be of different widths and therefore the actual width of the concrete forming panel can easily be modified to meet a particular need of a contractor or a client. With wider concrete forming panels, it may be appropriate to also provide some tack welding of the bracing members to the various support members where they engage or pass over the bracing members. 
     The panel sections as described extend in the length of the panel; however it is also possible to use shorter panel sections extending in the width. This arrangement is less desirable as the number of seams increase and the bracing would then extend in the length. 
     It has been found that this concrete forming panel, using the mechanical connection of a plurality of sections, provides a structure which is cost effective to produce and provides excellent characteristics with respect to finish and durability. The design allows easy modification for building of concrete forming panels in different widths and lengths as may be required. 
     It is possible to modify the individual panel sections, the bracing members and end rails to provide appropriate support. For example, where loads are higher, the bracing members may be slightly wider or more bracing members provided to provide proper support. The desired trapezoidal shape of the brace members is also convenient for a worker to grasp and is of assistance in assembly and dismantling. 
     Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.