Abstract:
A system is disclosed for securing a layer of insulation in place between two spaced apart wall forms while concrete is poured on both sides of the insulation layer.

Description:
RELATED APPLICATION 
     This Application is a Continuation-In-Part of application Ser. No. 09/065,285 filed Apr. 23, 1998 now U.S. Pat. No. 6,079,176 which is based upon Provisional Application Ser. No. 06/060,364 filed Sep. 29, 1997, the priority dates of both Applications being hereby claimed and being hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to poured concrete walls and, more particularly, to poured concrete walls including a layer of thermal insulation for reducing heat transfer in which the insulation layer is secured to the concrete wall at the time of pouring the concrete. 
     BACKGROUND 
     Concrete walls are commonly formed by pouring concrete between inner and outer forms and, after hardening, insulation materials for reducing the thermal R valve may be added to the concrete walls. In order to do so, frame members may be applied to the concrete wall, such as by using pneumatic guns and concrete nails, and then the insulating material may be secured to the frame members. Alternatively, the insulation may be secured to the concrete wall by concrete nails. Such multi-step assembly procedures are both time consuming and costly. Thus, there has long been a need for a system and a method whereby poured concrete walls may be formed and insulated at the same time in one step. 
     SUMMARY 
     The present invention provides an apparatus and method for securing an insulation layer in place while the concrete is poured between conventional forms, and for continuing to secure the insulation layer to the poured concrete wall after the forms have been removed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional view of a poured concrete wall with a thermal insulation layer secured thereto; 
     FIG. 2 is a cross-sectional view taken along line  2 — 2  of FIG. 1; 
     FIG. 3 is an enlarged side-elevational view of one tie strip; 
     FIG. 4 is a top plan view of a wedge which is inserted into the tie strip; 
     FIG. 5 is an enlarged, side elevational view of one form of support element for securing the insulation layer to the concrete wall prior to, during, and after the concrete is poured; 
     FIG. 6 is a front plan view of the support element taken along line  6 — 6  of FIG. 5; 
     FIG. 7 is a top plan view of the support element taken along line  7 — 7  of FIG. 5; 
     FIG. 8 is an elevational view of a plurality of insulation panels secured to the concrete wall by a plurality of support elements; 
     FIG. 9 is a vertical cross-sectional view of a portion of the concrete wall showing an alternative position of the insulation layer; and 
     FIG. 10 is a horizontal cross-sectional view of the concrete wall taken along view line  10 — 10  of FIG.  9 . 
    
    
     DETAILED DESCRIPTION 
     Referring first to FIG. 1, numeral  10  designates a concrete wall which has been poured between first and second conventional forms  12  and  14 . Forms  12 ,  14  are held together by metal strips or ties  16  as in conventional practice. However, as shown most clearly in FIG. 3, each of ties  16  includes a non-conventional slot  17  for a purpose hereinafter described. Numeral  18  represents a conventional footing for supporting the wall, and numeral  20  represents a plurality of conventional reinforcing bars (“rebar”) which extend horizontally through the poured concrete to add strength to the wall. 
     The structure described thus far is typical of the manner of forming poured concrete walls. After the concrete hardens, forms  12  and  14  are removed and the concrete wall is complete. If insulation is to be added, frame members (not shown) must be secured to the wall, or sheets or rolls of insulation must be secured by pneumatic nailing guns. As previously stated, this double-step procedure is both time consuming and costly. 
     In the present invention, layers or panels of insulation  22  are secured in place before the concrete is poured between forms  12 ,  14 . The means for securing the insulation in place during the pouring of the concrete comprise clips or wedges  23  and anchors or connectors  24 . Clips or wedges  23 , hereinafter wedges, are shown in detail in FIGS. 2 and 4. Each wedge comprises a molded piece of plastic, such as polypropylene, which is in the form of a double-ended V-shape with an open hole  26  in the central region. As such, the wedges are flexible and resilient so that they may be squeezed together in the center portion and inserted into slots  17  of ties  16 . Upon insertion, the center portions of the wedges expand such that grooves  28  lock in ties  16  and the wedges extend horizontally. As shown most clearly in FIG. 2, approximately one-half of each wedge becomes embedded in the insulation panel, and the other half becomes embedded in the poured concrete. As a result, the insulation panels become locked to fixed ties  16  so that the lightweight panels cannot “float” upwardly when the concrete is poured. 
     In addition to ties  16  and wedges  23 , the present invention provides anchors or connectors  24  as shown in FIGS.  1  and  5 - 7 . Preferably, connector elements  24  are in the form of a web portion  32  having openings  34  so that the poured concrete passes through and fills the openings as shown in FIG.  1 . Thus, as the concrete hardens, connectors  24  become bound and locked in the concrete. 
     As further shown most clearly in FIGS.  1  and  5 - 7 , each connector  24  includes an enlarged head portion  36  which extends laterally and vertically at a right angle relative to the web portion. Thus, when the web portion of each connector passes through a slot  38  in the insulation panel as shown in FIGS. 1 and 8, the panel is retained by head portion  36  while the web portion is retained in and by the concrete. In the preferred embodiment, it will be understood that the area of the insulation surrounding slot  38  may be recessed or counter-sunk such that the exposed surface of the connector head is flush with the surface of the insulation. However, the thickness of the head portion is only in the order of ¼ inch or less such that counter-sinking is not necessary. 
     Also in the preferred embodiment, stiffening side bars or ribs  37  may be added as most clearly shown in FIGS. 5 and 7, and the stiffening ribs may be provided with barbs  39  for engaging in insulation layer  22 . Also, the upper and lower portions of connectors  24  may be provided with barbs  41  which further engage and hold the insulation panel in place. In addition, in order to accommodate walls of either 6 or 8 inches in thickness, the horizontal length of connectors  24  may be manufactured of a uniform 8 inch length, and with grooves  42  as shown in FIG. 5 near the tip of the connector such that the tip may be easily broken off for 6 inch walls. 
     In the foregoing description, connectors  24  may be held in place during the concrete pouring by virtue of a tight frictional fit between the web portion  32  and slot  38  of the insulation panel and the frictional engagement of barbs  39  and  41 . However, a substantially greater securing of the connectors may be effected by providing one or more notches, grooves or hook portions  40  as shown in FIGS. 1 and 5. These hook portions may be engaged by rebar  20  so as to positively lock connectors  24  in place before, during and after the concrete is poured 
     Connectors  24  may be composed of any rigid material, but they are preferably composed of molded plastic such as for example, polypropylene or polyethylene. Such materials may be easily molded, are of low thermal conductivity and are low cost. Most importantly, they provide an excellent medium for receiving nails, screws, staples or other means through heads  36  for securing the later installation of additive wall materials such as plaster board, paneling or other finishing layers. 
     Insulation layer  22  may be composed of any commercially available material of low thermal conductivity, but is preferably composed of rigid panels of expanded or extruded polystyrene. In addition to the thermal insulation value of such panels, their inherent properties provide a vapor barrier and their thermal properties are not deteriorated by moisture. 
     From the foregoing description of one preferred embodiment it will be apparent that numerous variations in the details will be readily apparent to those skilled in the art. For example, as shown in FIGS. 9-10, insulation layer  22 ′ may be positioned within the interior of concrete wall  10  during the pouring of the concrete. This is of particular benefit in the pouring of concrete walls for commercial-type buildings where no additional finishing of the interior wall is to be provided for after the pouring. In this situation, ties  16 ′ are provided with two slots  17  and  17 ′ and, as shown in FIG. 10, two wedges  23  and  23 ′ are engaged in these slots such that approximately half of each wedge is embedded in foam insulation  22 ′ and the other half becomes embedded in the poured concrete. In any event, wedges  23  and  23 ′, and ties  16 ′ with double slots  17 ,  17 ′ positively engage the insulation layer  22 ′ and hold it securely, and against floating or otherwise moving upwardly or sideways during the pouring of the concrete. This embodiment produces an insulated wall of the same R value as previously described, but with the insulation layer contained within the concrete wall despite the very substantial buoyant forces which are encountered in the pouring of the concrete. 
     Accordingly, it will be understood that the foregoing description is purely illustrative of the principles of the invention, and that the invention is not intended to be limited other than as expressly set forth in the claims interpreted under the doctrine of equivalents.