Abstract:
A system for tilt-up concrete panel forming for use on a casting surface comprising an elongated base strip having an elongated groove in an upper surface, having a chamfered edge, and having a bottom surface adapted to be adhesively attached to the casting surface. The base strip has a support edge on the upper surface for receiving and supporting an elongated wooden panel form. A plurality of brackets each have a bottom section for mating with the elongated groove of the base strip at spaced intervals along the base strip, and the brackets further including a support section for supporting a side of the panel forms. Suitable clips can be added to the support sections of the brackets to impart a camber to an end of the concrete panel being formed.

Description:
The present invention relates to the manufacture of tilt-up concrete panels, and more particularly to a system of components for facilitating casting of panels on a casting surface without the need for penetrations, as by nails in drilled holes, of the casting surface as is common in traditional panel forming methods. 
     BACKGROUND 
     It is well known in the process of manufacturing concrete walls or wall sections to form them on a substantially flat, hard surface such as a concrete floor, and subsequently to tilt up the hardened and cured concrete section to form a wall or wall section. It is common practice in the construction industry to pour several walls or wall sections of a building on a previously poured and hardened floor of the building under construction. In doing so, a suitably large area of the floor is formed or fenced off by a plurality of wooden forms which define the edges of the final wall or section. These forms are attached to the floor so as to prevent dislocation or movement, particularly in a lateral direction. The surface of the floor is provided with a suitable bond-beaker material in order to prevent the newly formed section from adhering to the floor. A concrete mix is then poured into the area fenced off by the wooden forms. After curing and hardening of the newly poured concrete, the wooden forms are removed and the concrete wall section is lifted off the floor by a crane or other suitable device to complete a wall section of the building. 
     The usual practice after.the concrete floor or foundation has been poured and cured is that a wooden form is constructed on the floor into which concrete for the wall panels can be poured. The wall form: is a wooden plank, such as a 2×10 plank and which is supported by wooden brackets spaced along the form at, for example, 2 foot intervals, and nailed to the concrete floor. This type of installation involves a substantial amount of manual labor. In addition, after the concrete panel is cast into the form area, the forms and base and whatever brace members are used must be removed and, importantly, the nail holes in the floor need to be patched. This involves additional manual labor. Presently, one may end up with 1,000-10,000 such holes in the concrete floor which must be patched. 
     Also, a chamfer strip is added inside of the resulting form adjacent the floor and forms to suitably chamfer the edge of the concrete wall panel. If this is not done, the edge tends to crumble after the wall: is completed. 
     Example prior art systems can be found in U.S. Pat. No. 4,393,568, U.S. Pat. No. 4,101,111 and U.S. Pat. No. 4,042,205. 
     SUMMARY OF THE INVENTION 
     The present invention eliminates the need for nailing wooden forms to a concrete or other floor or base, and the need for adding a chamfer strip. This is accomplished by providing an elongated base track or strip and brackets attached thereto to support a wooden form between.the base and bracket. Preferably, the bracket and strip are configured so that the bracket can merely snap into a channel or longitudinal slot in the base track. The bottom of the base track has secured thereto one or more strips of two sided adhesive along the whole length of the base track to adhere the base track to the concrete floor onto which the wall section is to be poured. The base track itself has a chamfered edge for providing a chamfer on an edge of the concrete wall. This system eliminates the need for penetrating the floor with nails or other fasteners and thus also eliminates the need to patch the resulting holes. Furthermore, no separate chamfer strip is needed. Also, the components may be reusable. 
     In a presently preferred embodiment, a base strip and bracket are provided along with a batter clip attachable to the upper end of the bracket so as to position the wooden form at a slight angle or cant the form, so as to provide a camber at one end or side of a concrete panel which will become the top or roof line of a wall. The batter clip pushes the form away from the bracket by a small angle to create the camber. The camber created by this technique is an important feature to reduce the problem when dust collects at the top of a panel used as a wall, at the roof line. Because of this, the dust and dirt that collects on the top can work itself down inside the wall rather than down the outside. This is advantageous because if the dust works down the outside of the wall and it rains, the outside of the wall is streaked with the moist dust and dirt. 
     Accordingly, it is an object of the present invention to provide an improved concrete panel forming system. 
     Another feature of the present invention is to provide components and a system for forming tilt-up concrete panels without requiring penetration of the base surface by fasteners such as nails and the like. 
     Another feature of the present invention is to provide a concrete panel forming system comprising an elongated base track and support brackets which snap into a channel in the base track for supporting a wooden form. 
     Another feature of the present invention is a tilt-up concrete panel forming system incorporating an integral chamfer strip. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     These and other objects and features of the present invention will become better understood through a consideration of the following description, taken in conjunction with the drawings in which: 
     FIG. 1 is a perspective view of the present concrete panel forming system showing a base track and bracket thereof. 
     FIG. 2 is an end cross-section of the system of FIG. 1 taken along a line  2 — 2  but further showing the position and support for a wooden form, 
     FIG. 3 is an end view of the bracket of the system of FIGS. 1 and 2, 
     FIG. 4 is a view of a pre-made corner section of base strips, 
     FIG. 5 illustrates another embodiment of a base strip and bracket, 
     FIG. 6 illustrates another and preferred embodiment of a base strip and bracket, 
     FIG. 7 is a detailed view of the upper end of the bracket of FIG. 6, 
     FIG. 8 is a perspective view of a batter clip used with the bracket of FIG. 6 (and also shown in FIG.  6 ), and 
     FIG. 9 a  is a cross-sectional diagrammatic end view of the base strip and bracket of FIG.  6  and also illustrating a wooden form and the manner in which the batter clip cants the wooden form, and FIG. 9 b  illustrates a smaller version of the bracket. 
    
    
     DETAILED DESCRIPTION 
     Turning now to the drawings, the present tilt up concrete panel forming system comprises a base track or strip  10  and a bracket  12 . The base strip  10  typically is 5′ or 10′ in length and is placed on.a concrete floor  14 . The strips  10  are laid end-to-end as necessary depending on the length and width of the final wall. The base strips  10  are secured to the concrete floor  14  by one or more double sided adhesive strips  16  after the floor is cleaned, such as by vacuuming or sweeping and then picking up dust with a damp rag, preferably before any bond breaker is applied to the concrete floor. The strips  16  run the length of the base strip  10 . 
     The base strip  10  includes an angled side  18  which provides the function of a separate chamfer strip as used in the prior art. The strip  10  also includes a longitudinal slot  20  which has angled sides  22  and  23  as seen in FIGS. 1 and 2 into which the bracket  12  is inserted as will be discussed subsequently. Preferably, the base strip  10  is formed of a suitable plastic material which has some resiliency to facilitate the base  30  of the bracket  12  snapping into the slot  20 . A plurality of the brackets  12  are inserted into the base strip, such as at 2 foot intervals to suitably support a wooden form  26  (note FIG.  2 ). 
     Turning now to more details of the bracket  12 , the same includes the base  30  having angled walls  32  and  33  to fit or snap into the slot  20  of the base strip  10  adjacent to and mate with the angled walls  22  and  23  of the strip  10 . The bracket  12  further includes an upstanding support  36  which “backs up” the wooden form  26 . The bracket  12  has an angle brace  38 , the lower end  40  of which rests on the concrete floor  14 . The upper end  42  of the support  36  provides an area through which a suitable screw fastener (not shown) can be inserted as through a groove  44  as seen in the end view of the brace  12  in FIG. 3 to securely affix the bracket  12  to the wooden form  26 . The wooden form typically is a 2×6, 2×8, or the like. Preferably the brackets  12  are made in different sizes for different applications, such as for different thickness wall panels. The brackets can be formed from extruded plastic or aluminum and cut into sections to form the same or they may be injection molded of plastic. 
     FIG. 4 illustrates a premade corner for the base strips  10 . As can be seen, two short lengths (e.g., 1 foot), strips  10  are cut at a 45° angle as seen at  50  and glued together by suitable adhesive, such as PVC glue. This arrangement provides a premade corner to simplify installation of the present forming system. 
     As will be appreciated, the present system provides a relatively simple way of setting up concrete forms by merely laying down the base strips  10  which are secured to the floor  14  (after suitable preparation of the floor, e.g., to remove dust, etc. as noted above), inserting a plurality of the brackets  12  into the longitudinal groove  20  of the base strips  10 , and the wooden forms  26  are placed on the strips and secured at a groove  44  (FIG. 3) to the forms  26 . This system simplifies and facilitates setting up the forms, does not require the numerous nailing and nail holes thereby minimizing the labor for both installation and removal. Additionally, the components, namely the base strips  10  and brackets  12 , may be reusable although new adhesive strips  16  may be needed. 
     The present system provides a complete tilt-up concrete forming system that eliminates the need for penetrations in the casting surface, i.e., the floor or slab  14 , as is common in traditional panel forming methods. This system increases productivity and simplifies panel forming operations, and eliminates the need to patch thousands of holes which in the prior art systems are drilled in the casting surface when using traditional panel forming methods. The base track or strip  10  incorporates the continuous chamfered edge  18  thereby eliminating the need to use a separate chamfer strip and the need to nail on a separate chamfer strip after the panel forms are erected. The base track  10  can be formed from plastic material which eliminates the usual dusting effect from a chamfered edge of wood which contains natural sugars that retard concrete curing. The use of two sided adhesive strips or tape  16  to adhere the base track  10  to the casting surface  14  provides continuous support along the entire length of the panel forms to resist pressure from the concrete during the placing operation. The base tracks and brackets may be reusable, and the brackets easily snap into the base track. The angled surfaces  32  and  33  of the bracket  12  and the angled surfaces  22  and  23  of the longitudinal groove  20  of the base strip  10  prevent uplift of panel forms during the concrete placing operation. The angled rear brace  38  of the brackets  12  extend beyond the base strip  10  at  40  to contact the casting surface  14  directly to keep the form panel plumb. The upper end  42  of the bracket  12  preferably is provided with the groove  44  to facilitate alignment and guiding of a self-tapping screw to attach the bracket  12  to the wooden form  26 . Only one self-tapping screw per form bracket  12  is needed to hold the panel form  26  in place. The use of the groove for this purpose reduces labor costs which would be required if a hole had to be drilled for a nail or screw. The brackets  12  can be placed at any point along the entire length of the base strip  10  as necessary to support the form  26 , usually several feet apart. The brackets  12  can be manufactured in different sizes for varying concrete panel thickness. 
     Turning now to FIG. 5, the same illustrates a second embodiment which may be preferred for some applications. This embodiment is similar to that of FIGS. 1 through 3, but the base strip  110  has a deeper cavity or opening  124  so that the form  26  fits down further into the base strip. The bracket  112  is similar to the bracket  38  with a base section  130  having angled edges  132  and  133  to fit within the groove  120  and angled edges thereof  122  and  123 . The bracket  112  further includes an offset angled section  144  which allows the upstanding support  136  to properly engage and back-up a wooden form  26 . This is needed because of the offset occasioned by section  125  of the base strip  110 . As with the embodiment of FIGS. 1 through 4, this embodiment of a base strip and bracket has like features and benefits. 
     Turning now to the embodiment of FIGS. 6 through 9, and which is believed to be a preferred embodiment, the components are similar to those of the previous two embodiments but with some important differences. This embodiment includes a base strip  210  and bracket  212 . The base strip  210  is simpler in that a slot or groove  220  is in the form of a U-shaped channel (note particularly FIG. 9) for receiving an L-shaped foot  230  of the bracket  212 . The base strip  210  includes a cavity  224  for receiving the lower end of the form  226  (not shown in FIG. 6, but note FIG.  9 ). The base strip also includes an angled side  218  which provides the function of a separate chamfer strip as previously discussed. 
     The bracket  212  includes an upstanding support  236  and an angle brace  238  which has a foot  240 , all very similar to those of the preceding embodiments; however, in this embodiment the bracket  212  is of a T-beam shape as can best be seen in FIG.  6 . The upper end  242  of the bracket  212  has an aperture  244  (note also the detail of FIG.  7 ). Adjacent the opening  244  at the upper end  242  of the bracket  212  is a U-shaped boss  250  which is configured to receive and couple with U-shaped fingers  252  and  254  of a batter clip  256 . The batter clip  256  slides onto the upper end  242  of the bracket  212  around the boss  250  and engages fingers  260  and  262  of the end  242  of the bracket  212  to firmly support the batter clip  256  on the upper end  242  of the bracket  212 . The clip  256  also has a through aperture  258  (FIG. 8) as a continuation of the aperture  244  in the upper end  242  of the bracket  212  to allow the upper end  242  of the bracket  212  to be firmly attached to the wooden form (note FIG. 9) by a nail or screw. 
     The main purpose of the batter clip  256  is to hold the form  226  outwardly at an angle as seen in FIG. 9 to cause a camber to be provided to the edge of the concrete panel when this edge is to be the top of a concrete panel at a roof line for the purposes as previously described. That is, the camber or slight angle is provided on the edge  264  of the concrete panel  265  by the form  226  so that when dust collects on the cambered top ( 260 ) of the panel the dust can fall to the inside of the building rather than the outside of the building to minimize dirt streaking the outside wall. An exemplary angle imparted to the form by the clip  256  is approximately 7 degrees, although different angles can be provided as desired. 
     FIG. 9 a  shows the bracket  212 , clip  256  and strip  210  of FIGS. FIG. 9 b  shows a smaller version of a bracket  212   a , clip  256   a  and the strip  210 . An example width at the base of the bracket  212  is 5.44 inches (and 3.345 inches on bracket  212   a ) and height of 8.76 inches (and 5.263 inches for  212   a ). 
     Each of the components in the embodiment of FIGS. 6 through 9 can be injection molded of a suitable material such as polypropylene, although the components can be either plastic or metal as may be desired. 
     While embodiments of the present invention as been shown and described, various modifications may be made without departing from the scope of the present invention, and all such modifications and equivalents are intended to be covered.