Patent Publication Number: US-2021164234-A1

Title: Clip for cast stone wall system

Description:
FIELD OF THE INVENTION 
     The present invention relates to cast stone decorative wall systems and to specialized tenon clips for fastening the cast stone elements to a load supporting wall or structure. 
     BACKGROUND 
     Thin stone wall cladding products are available in the marketplace. When installed, an attractive natural stone appearance is presented. However, commercialization of this decorative wall facing option is slow in acceptance in part because of an inability to easily and inexpensively attach the facing stone elements to a vertical wall structure. 
     Typically in the art, thin stone wall systems are installed by the so-called “lick and stick” method, which involves the use of epoxy adhesive to secure the thin stone or thin brick to plywood or OSB wall cladding, which involves the use of metal lath with a scratch coat of Portland mortar. Such an adhered thin stone system is inherently less secure since improper application of the adhesive can lead to stones separating from the wall, which is both a nuisance and a safety problem. Such adhered thin stone systems are typically only used in lower floor applications of residential and commercial buildings as there is a bias against their use on multi-floor buildings. Further, the adhered thin stone system is not used in conjunction with other wall elements such as drainage board and weather-resistant wrap. Accordingly, thin stone products have in the main been used primarily in commercial building applications. 
     Various bracket or clip systems have been developed to affix decorative veneer panels made to look like stone to a vertical structural wall. Although useful in particular cases, such systems lack versatility and simplicity, requiring brackets or clips with complicated structures and/or several separate components. Such brackets or clips are difficult to secure to structural walls and require time-consuming alignment of panels. 
     There remains a need in the art for a more versatile, secure, and mechanically stronger thin stone wall system that is less costly, easier and faster to install and requires less skilled labor. 
     SUMMARY OF THE INVENTION 
     A tenon clip for affixing cast stone elements to a supporting wall surface, according to the present invention, has a U-shaped fastening portion with a first fastening side and opposing sidewalls generally perpendicular to the first fastening side. An anchoring flange extends from each of the sidewalls. The first fastening side has a fastening aperture therethrough for fastening the tenon clip to the supporting wall surface. Each anchoring flange has one or more anchors to secure the tenon clip within the cast stone element. 
     In another embodiment, the one or more anchors comprises one or more apertures through the anchoring flanges. 
     In another embodiment, the one or more anchors comprises a tab extending generally perpendicularly from the anchoring flanges. 
     In another embodiment, the tenon clip has a length and the cast stone element has a height separating opposing top and bottom edges. The length of the tenon clip is greater than the height of the cast stone element. 
     In another embodiment, the fastening aperture is located adjacent one end of the first fastening side. A second fastening aperture is located adjacent the opposite end of the first fastening side. 
     In another embodiment, the length of the anchoring flanges is substantially equal to the height of the cast stone element and the tabs are positioned at the top and bottom edges of the cast stone element. 
     A cast stone wall system, according to the present invention, has a supporting wall surface, a cast stone element having a decorative face, a rear face opposite the decorative face, a top edge, and a bottom edge, and a tenon clip having a U-shaped fastening portion with a first fastening side and opposing sidewalls generally perpendicular to the first fastening side. An anchoring flange extends from each of the sidewalls and is at least partially embedded in the rear face of the cast stone element. The first fastening side has a fastening aperture therethrough for fastening the tenon clip to the supporting wall surface. Each anchoring flange has one or more anchors to secure the tenon clip within the cast stone element. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the invention may be more clearly understood, embodiments thereof will now be described in detail by way of example, with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective rear view of a cast stone element with embedded tenon clips, according to the present invention. 
         FIG. 2  is a top view of the cast stone element of  FIG. 1 . 
         FIG. 3  is a rear view of the cast stone element of  FIG. 1 . 
         FIG. 4  is a rear view of a number of cast stone elements with embedded tenon clips of a cast stone wall system, according to the present invention. 
         FIG. 5  is a cross-sectional view of the cast stone wall system of  FIG. 4 , along the lines A-A in  FIG. 4 . 
         FIG. 6  is a cross-sectional view of the cast stone element of  FIG. 1 , along the lines C-C in  FIG. 3 . 
         FIG. 7  is a perspective view of a tenon clip, according to the present invention. 
         FIG. 8  is a front view of the tenon clip of  FIG. 7 . 
         FIG. 9  is a side view of the tenon clip of  FIG. 7 . 
         FIG. 10  is a top view of the tenon clip of  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The tenon clip and cast stone wall system, according to the present invention provide an aesthetically pleasing stone wall appearance with ease of installation. The cast stone elements may be affixed to a supporting wall surface by means of the tenon clip, which provides a convenient means of attachment and spacing between the cast stone elements and the supporting wall to allow for drainage. The tenon clips are inserted into the cast stone, during the casting process while the material is wet, thereby embedding the tenon clip within the cast stone element. A single tenon clip may be used, which spans the height of the cast stone element and extends past the top and bottom edges, or two tenon clips may be used, which are positioned opposite one another at the top and bottom edges of the cast stone element. 
     As shown in  FIGS. 1-3 , a cast stone element  1  has a front decorative face  2 , rear face  3 , top edge  4 , and bottom edge  5 . The cast stone element is formed by pouring wet casting material, such as concrete, into a mold. In some embodiments, the front decorative face  2  is made up of a layer of natural stone, which is set in the mold prior to pouring wet casting material into the mold. In one exemplary embodiment, the cast stone element  1  has a height of 215 mm, a length of 620 mm, and a thickness of 40 mm, with two tenon clips  10  positioned along the length of the cast stone element  1  about 123 mm from either end  6 . The ends  6  of the cast stone element  1  may be shaped to overlap with adjacent cast stone elements  1 . As shown in  FIG. 3 , each end  6  has a cut-out  7  at the top or bottom edge  4  or  5 , shaped complementary to a tab  8  at the other end  6 . Alternatively, the ends  6  may be flat or have another convenient shape to facilitate engaging adjacent cast stone elements  1  to cover a supporting wall surface. 
     A tenon clip  10 , as shown in  FIGS. 7-10 , is used for attaching the cast stone elements  1  to plywood, drainage board, or other supporting wall structure. By inserting the tenon clip  10  into the cast stone element  1  during casting, the tenon clip  10  is securely retained therein. The tenon clip  10  has a generally U-shaped fastening portion  11  with a first fastening side  12  and two opposing sidewalls  13 . The sidewalls  13  are connected to the first fastening side  12  at the corners of the U-shape and generally perpendicular to the first fastening side  12 . An anchoring flange  14  extends from each of the sidewalls  13  and is at least partially embedded in the rear face  3  of the cast stone element  1 , as shown in  FIG. 6 . Preferably, the anchoring flanges  14  are entirely or substantially embedded within the cast stone element  1 , while the fastening portion  11  of the tenon clip  10  extends outwardly from the rear face  3  of the cast stone element  1  to provide spacing between the rear face  3  of the cast stone element  1  and the supporting wall surface. Preferably, the anchoring flanges  14  are embedded in the cast stone element  1  when the concrete or other material of the cast stone element  1  is in a wet state, prior to curing. Alternatively, the anchoring flanges  14  may be inserted into angle grooves or kerfs cut into the rear face  3  of the cast stone element  1 . The first fastening side  12  has a fastening aperture  15  therethrough for fastening the tenon clip  10  to the supporting wall surface, thereby securing the cast stone element  1  to the supporting wall surface. 
     The anchoring flanges  14  have one or more anchors to improve the pull-out strength and help secure the tenon clip  10  within the cast stone element  1 . As shown in  FIGS. 6-9 , the anchors may be apertures  16  through the anchoring flanges  14  that permit the material of the cast stone element  1  to flow through the anchoring flanges  14  to secure the tenon clip  10  and prevent it from moving or slipping relative to the cast stone element  1 . Additionally, tabs  17  may be provided extending perpendicularly from the anchoring flanges  14 , parallel to the top and bottom edges  4  and  5  of the cast stone element  1 . Preferably, as shown in  FIGS. 3 and 6 , the tabs  17  are positioned at or just beneath the top or bottom edges  4  or  5  of the cast stone element  1 , but other configurations of tabs may be used in addition to or in place of apertures  16  or other types of anchors to secure the anchoring flanges  14  within the cast stone element  1 . Preferably, the tenon clip  10  is configured such that it can be made by bending and cutting a single piece of metal. 
     As shown in  FIG. 3 , the length of the tenon clip  10  is slightly longer than the height of the cast stone element  1 , such that the fastening apertures  15  near the ends of the tenon clip  10  are positioned above or below the top or bottom edges  4  or  5  of the cast stone element  1 . This permits a fastener to be driven through the fastening aperture  15  into the supporting wall surface with the cast stone element  1  in position against the supporting wall surface and any adjacent cast stone elements  1 . As shown in  FIGS. 4 and 5 , each successive row of cast stone elements  1  in a cast stone wall system, using the cast stone elements  1  and tenon clips  10  of the present invention, may be positioned resting directly on top of the row below with substantially no space therebetween. The fastening portion  11  of the tenon clip  10  which extends above and below the top and bottom edges  4  and  5  of the cast stone element  1  slides into the space between the rear face  3  of the cast stone element  1  below and the supporting wall surface. 
     Alternatively, the tenon clip  10  may be shorter than the height of the cast stone element  1 . A tenon clip  10  may be positioned at the top edge  4  and another at the bottom edge  5  of the cast stone element  1 . The shorter tenon clips  10  may be configured the same as the longer tenon clips  10 , which span the entire height of the cast stone element  1 , except that they, preferably, do not have tabs  17  at both ends and the fastening portion  11  does not extend beyond the anchoring flanges  14  at both ends. In this embodiment, tabs  17  are positioned substantially at the top or bottom edge  4  or  5  of the cast stone element  1 , the fastening portion  11  of the tenon clip  10  extends beyond the same top or bottom edge  4  or  5 , and the tenon clip  10  extends towards the other top or bottom edge  4  or  5  by a distance less than the height of the cast stone element  1 . 
     A starter strip may be used to support the bottom row of cast stone elements  1  from below, from above, or from one side. The starter strip has a support flange and a base flange extending from the support flange, preferably, at a right angle. The support flange has one or more apertures for receiving fasteners to attach the starter strip to the supporting wall surface. The base flange may have one or more drainage apertures for permitting moisture to escape from between the cast stone elements  1  and the supporting wall surface. The starter strip has a length long enough to span two or more cast stone elements  1  and, preferably, between about 3′ to 12′, more preferably, between 4′ and 8′. 
     The starter strip may be straight or curved and may have an L-shaped or J-shaped cross section. Where the tenon clip  10  extends beyond both the top and bottom edges  4  and  5  of the cast stone element  1 , a J-shaped starter strip may be used to accommodate the tenon clip  10  extending below the bottom edge  5  of the cast stone element  1 . Curved starter strips may be used to span archways, windows, and the like. 
     Optionally, the tenon clip  10  may be shimmed with reference to the supporting wall surface to leave space between the supporting wall surface and the first fastening side  12  of the tenon clip  10 . In this way the spacing between the cast stone element  1  and the supporting wall surface may be selectively adjusted, as required, for example, to accommodate any uneven areas on the supporting wall surface. A shim feature may be provided at the rear of the tenon clip  10 , such as a raised flexible indent portion or biasing tab. An installer may incrementally depress the tab to provide the desired spacing. 
     The vertices of the tenon clip  10 , such as the corners of the U-shaped fastening portion  11  and the point at which the anchoring flanges  14  extend from the sidewalls  13 , may be structurally reinforced to prevent relative bending between the parts of the tenon clip  10 . Preferably the vertices are structurally reinforced by way of crimps, welds, or channels formed on the vertices of the tenon clip  10 . 
     A cast stone element  1 , according to the present invention, may be prepared by placing a tenon clip  10  in a mold with the anchoring flanges  14  facing downwardly and at least partially immersed in the wet casting material in the mold. The tenon clip  10  is positioned with the U-shaped fastening portion  11  above the casting material and resting on the top edges of the mold. Several tenon clips  10  may be positioned across the top of the mold, as required. Preferably, two tenon clips  10  are used, located to each side of the mold, as shown in  FIGS. 1-3 . Optionally, the tabs  17  may be used to locate and guide the tenon clip  10  into position in the mold. As the casting material hardens, the tenon clips  10  become securely attached to the cast stone element  1  by means of the anchoring flanges  14  embedded within the rear face  3 . A cast stone element  1  is thereby produced, which may be attached to a supporting wall surface by driving a fastener through the fastening aperture  15  of the tenon clip  10 . 
     A cast stone wall system, according to the present invention, permits the convenient and secure installation of cast stone elements  1 , with embedded tenon clips  10 , as described herein, on a supporting wall surface to provide a decorative stone finish to the wall, without using adhesives to affix the cast stone elements  1  to the wall. 
     The present invention has been described and illustrated with reference to an exemplary embodiment, however, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention as set out in the following claims. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed herein.