Patent Publication Number: US-2013232897-A1

Title: Anchor system for securing a concrete wall panel to a supporting concrete foundation

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a connector or anchor for connecting a cast concrete wall panel to a poured concrete foundation, for example, as disclosed in U.S. Pat. No. 5,609,005, the disclosure of which is herein incorporated by reference. In this patent, a connector includes an inverted V-shaped angle member having an inclined surface supporting an inclined tubular member which extends to the outer surface of the wall panel. An anchor rod is inserted through a hole within the angle member and into an inclined hole drilled within the concrete foundation. The anchor rod is secured within the concrete foundation with an epoxy adhesive, and a nut is threaded onto the upper end portion of the anchor rod after the adhesive is cured. Commonly, each concrete wall panel is cast horizontally on a poured concrete floor after the concrete floor cures, and the cured wall panel is tilted upwardly to a vertical position and located where the anchor rods are inserted into the drilled holes within the concrete foundation. After the epoxy cures and the nut is threaded onto the upper end portion of the rod, the tubular member is commonly filled with grout, and earth may be filled in outside the wall panel to cover the grout on each connector 
     It has been found desirable to connect the cast concrete wall panels to the supporting foundation with a connector or anchor system which permits anchoring the vertical wall panel to the foundation from the inside surface of the wall panel and working from the concrete floor which has been poured onto the foundation. Locating the anchor system for access from the inside surface of the wall panel also provides for convenient access to the anchor system from the concrete floor and for faster and safer installation as well as for convenient inspection of the anchor system. Inside installation of the anchor system also avoids exposure of the anchor system to corrosion from exterior weather conditions and eliminates exterior patching of the anchor system with mortar to limit weather exposure. 
     GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is directed to an improved anchor system for securing a cast concrete wall panel to a supporting concrete foundation and which provides all of the desirable features and advantages mentioned above. In general, an anchor system constructed in accordance with the present invention includes a steel base plate which is positioned adjacent the bottom surface of the wall panel before the wall panel is cast, and a plurality of concrete reinforcing rods have lower ends welded to the base plate and project upwardly within the wall panel. A cavity forming member or tapered channel member has a lower end surface welded to the base plate and projects upwardly in flush relation with the inner surface of the wall panel. The channel member projects upwardly substantially above the floor surface and is slightly inclined on an acute angle less than twelve degrees and preferably about six degrees with respect to a vertical plane or the inner surface of the erected wall panel. 
     After the wall panel is lifted or tilted and erected to a vertical position and located outboard of the concrete floor, a hole is drilled into the concrete foundation on the acute angle and in alignment with a hole formed within the base plate at the bottom of the cavity defined by the channel member. A special self-tapping concrete anchor bolt is then extended through the hole in the base plate and threaded into the slightly inclined hole within the concrete foundation. The channel member provides for convenient access and alignment for drilling the inclined hole within the concrete foundation and for inserting the self-tapping concrete anchor bolt with a hand supported power operated impacting bolt driver. The base plate of the anchor system may be tilted by the slightly acute angle or the base plate may be horizontal and have an inclined spot face around the hole within the base plate at the acute angle. 
     Other features and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a wall panel anchor constructed in accordance with the invention; 
         FIG. 2  is a vertical section of the anchor taken generally on the line  2 - 2  of  FIG. 1 ; 
         FIG. 3  is a vertical section of a concrete wall panel, concrete foundation and concrete floor showing the anchor system with the anchor of  FIGS. 1 &amp; 2  installed for connecting the concrete wall panel to the concrete foundation in accordance with the invention; 
         FIG. 4  is another vertical section similar to  FIG. 3  and illustrating the attachment of a removable cap member onto a tapered channel member of the anchor shown in  FIG. 1 ; 
         FIG. 5  is a top end view of the cap member; 
         FIG. 6  is an elevational rear view of the cap member; and 
         FIG. 7  is an enlarged horizontal section of the installed cap member, taken generally on the line  7 - 7  of  FIG. 4 . 
     
    
    
     DESCRIPTION OF THE ILLUSTRATED EMBODIMENT 
       FIG. 1  illustrates a fabricated steel wall panel anchor  20  which is constructed in accordance with the invention and used for securing a cast concrete wall panel  22  ( FIG. 3 ) to a poured concrete footer or foundation  24  which may support a poured concrete floor  26 . The wall anchor  20  includes a flat steel base plate  30  having a length of about 13 inches, a width of about 6 inches and a thickness of ¾ inch. An elongated cavity defining member or tapered channel member  35  has an inner inclined wall  37  integrally connecting generally triangular opposite side walls  38 . The bottom ends of the walls  37  and  38  are welded to the base plate  30  so that the member  35  forms a tapering cavity  40 . The inner wall  37  of the cavity defining member or channel  35  is perpendicular to the base plate  30  which, as shown in  FIGS. 2 and 3  extends at an acute angle A less than twelve degrees and preferably about six degrees. A pair of right angle brackets  43  have vertical flanges  44  welded to the ends of the slightly inclined base plate  30  and include base flanges  46  which also extend at the acute angle A with respect to the bottom surface of the base plate  30 . The base flanges  46  have center holes  47 . 
     A set or pair of steel concrete reinforcing rods or rebars or bars  50  project upwardly from the base plate  30  on opposite sides of the cavity defining member  35  and have lower end portions  52  perpendicular to the base plate  30  and welded to the base plate. The reinforcing bars  50  have a slightly curved portion or bend  54  above the lower end portions  52  so that each bar  50  has an upper portion  56  which extends vertically within the wall panel  22 . The base plate  30  has a circular hole  58  of about 15/16 inch diameter within the bottom of the cavity  40 . 
     In a conventional manner, the wall panel  22  is cast in a horizontal position, for example, as disclosed in above-mentioned U.S. Pat. No. 5,609,005. When the forms for the edges of the wall panel are placed on the floor  26 , the wall anchor members  20  are attached to a form, for example, by nails or fasteners extending through the holes  47  within the brackets  43 . Each anchor  20  is positioned within the forms with the edge surfaces of the side flanges  38  of the channel  35  generally flush with the top surface of the edge forms so that the edges of the side flanges  38  will be generally flush with the inner surface of the wall panel after it has poured. 
     After the concrete in the wall panel  22  cures, the panel is lifted or tilted to a vertical position and positioned at the desired location on the foundation  24 , as shown in  FIG. 3 . An inclined hole  60  is drilled within the concrete foundation  24  with a concrete drill having an axis inclined on the angle A. The wall panel  22  is then secured or anchored to the foundation  24 , preferably, by a self-tapping steel anchor bolt  62  which has a shank portion  64  having a sharp helical thread  66  that penetrates the concrete in the foundation  24 . The shank portion  64  is integrally connected to an enlarged hexagonal head portion  68  having an outwardly projecting integral flange  71  larger than the hole  58  within the base plate  30 . 
     One company that makes a suitable bolt  62  is Simpson Strong-Tie Company, Inc. who produces a ten inch long bolt having a ¾ inch shank diameter and sold under the trademark SIMPSON Strong-Tie. The bolt  62  is threaded into the hole  60  by a power operated impacting socket wrench supported by an operator standing on the floor  26 . After the bolt  62  is tightened, it is capable of withstanding a substantial tension force, for example, 10,000 pounds. It is also apparent from  FIG. 3  that when the wall panel  22  is positioned on the foundation  24 , the cavity  40  is open to the inside surface of the wall panel above the top surface of the floor  26 . 
     To prevent concrete from entering the cavity  40  when the wall panel  22  is being cast horizontally, a removable cap member  75  may be attached or snap-fit onto the channel  35 , as shown in  FIG. 4 . Preferably, the cap member  75  is formed from an extruded plastics material such as polyvinylchloride (PVC) and is similar in construction to the joint cover disclosed in U.S. Design Pat. No. 445,921. The extruded cap member  75  includes an outer wall  78  having slightly angled edge portions  79  and is integrally connected to parallel spaced ribs  82  each having laterally outwardly projecting inclined flexible fins  84 . When the cap member  75  is pressed onto the channel member  35 , the fins  84  frictionally engage the inner surfaces of the side walls  38  of the channel member to retain the cap member  75  where the edge portions  79  of the cap member flex and engage the outer edge surfaces of the channel side walls  38  and also the flush inside surface of the wall panel  22 , as shown in  FIG. 7 . 
     As shown in  FIG. 6 , upper portions of the ribs  82  are cut away from the extrusion to form an upwardly projecting flange  87  of uniform thickness and which engages the inner surface of the wall panel  22 . At the bottom of the extruded cap member  75 , the ribs  82  may be cut away to form a downwardly projecting flange  88  which covers the inner edge surface of the base plate  30 . After the bolt  60  is tightened and the cap member  75  is reattached to the channel member  35 , the outer surface of the cap member wall  78  is substantially flush with the inner surface of the concrete wall  22  and provides a decorative cover for the channel member  35 . 
     From the drawings and the above description, it is apparent that a wall anchor system constructed and installed in accordance with the invention provides desirable features and advantages. More specifically, the anchor system provides for connecting or securing the concrete wall panel  22  to the concrete foundation  24  from inside the wall panel while the installer may be working on the concrete floor  26 . The use of the bolt  62  with the concrete cutting threads  66  also eliminates the use of securing an anchor rod or bolt to the concrete with epoxy and the time required for the epoxy to cure. In addition, the small acute angle A between a vertical plane and the axis of the hole  60  and bolt  62  enables the bolt to withstand a substantially high tension force for securing the wall panel  22  to the foundation  24 . The inclined position of the cavity defining member or channel  35  further helps to provide quick alignment reference for drilling the hole  60 . The removable cap member  75  also prevents concrete from flowing into the cavity  40  during casting of the wall panel and, in addition, provides a decorative cover for the anchor  20  after installation of the self-tapping bolt  62 . The position of the wall anchor  20  being flush with the inner surface of the wall panel  22  also eliminates the exposure of the wall anchor and the bolt  62  to exterior weather conditions in order to avoid corrosion of the anchor  20  and bolt  62 . 
     While the method and form of anchor system herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to the precise method and form anchor system described, and that changes may be made therein without departing from the scope and spirit of the invention as defined in the appended claims.