Patent Publication Number: US-2011067342-A1

Title: Embedded clip attachment for cast architectural element

Description:
RELATED APPLICATION 
     This is a divisional of application Ser. No. 12/113,605, filed May 1, 2008, and Applicants claim priority under 35 USC §120 from the above-identified parent application. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention generally relates to cast architectural elements, and more specifically to such elements used as simulated stone blocks for replacing more expensive and heavy solid ornamental stone on building exteriors and interiors. 
     For reasons of esthetics, lower maintenance and/or fire retardant properties, stone exteriors are preferred. However, due to the relatively high cost of the stone, particularly blocks of granite, marble or even limestone, as well as the technical challenge of handling and securing stone blocks to building substrates, there has been a demand for architectural elements made of simulated or artificial stone. Also, with the current interest in preserving resources, the use of solid stone blocks requires significantly more fuel for transportation due to vehicle weight restrictions. In many cases, cast architectural elements have a facing of relatively expensive pure or composite stone, with backings of less expensive, and typically relatively lighter weight materials. 
     One such product is a foam core architectural element that is coated to resemble stone and is sold under the trademark ELEGANT STONE™ by L&amp;W Supply of Chicago, Illinois (www.lwsupply.com). As is well known in the art, such products include an exterior surface of ornamental stone, such as limestone, marble, quartz, silica or the like in a cement matrix with aggregate in a castable formulation. Using a known foam casting technique, the element is produced so that the exterior shell is fused to an interior core of expanded polystyrene foam (EPS). The interior core is thus significantly lighter and easier to handle and install than conventional solid stone blocks. Also, this type of architectural element costs a fraction of solid stone. 
     Conventional cast architectural elements are secured to building exterior or interior substrates using adhesive and/or clamps which are fastened to the building substrate and grip the cast element in a peripheral groove. However, a drawback of such clips is that the installer needs to assemble them on site, and each clip requires multiple components which must be inventoried on site, and are easily misplaced during construction. 
     BRIEF SUMMARY OF THE INVENTION 
     The above-identified drawbacks of conventional cast architectural elements are met or exceeded by the present embedded clip attachment for a cast architectural element, which features the ability to install such elements on building exterior or interior substrates with fasteners as well as adhesive. With the present attachment, an attachment clip is embedded in the interior of the block, and is virtually impossible to pull out without destroying the block. In addition, the present attachment fully encases the foam core in stone or cement or settable matrix. A single integral clip has a portion for accommodating a fastener for securing the block to the building exterior or interior, and a second portion for engaging the foam core. 
     More specifically, a cast architectural element is provided, including a stone shell having front, end, side and rear walls defining an internal cavity, the rear walls defining a rear opening. A core is disposed in the internal cavity, and at least one attachment clip is provided having a first portion extending from the shell, and a second portion engaged in the core. A layer of mesh is disposed upon the core and the second clip portion, and a settable filler layer is disposed upon the mesh in the rear opening, such that upon setting, the filler retains the clip in position. 
     In another embodiment, a method of forming a cast architectural element is provided and includes the steps of providing a pre-cast element having a front, end, side and rear walls defining an internal cavity, the rear walls defining a rear opening, and forming edges of the rear walls to angle inwardly; providing a foam core disposed in the internal cavity; providing at least one attachment clip having a first portion extending from the shell, and a second portion with at least one tooth configured for insertion into the core, and placing the clips on said element so that the second portion engages the core; placing a layer of mesh upon the core and the second clip portion, so that edges of the mesh are beneath an inner corner of each edge; and applying a settable filler layer upon the mesh in the rear opening, such that upon setting, the filler retains the clip in position. 
     In yet another embodiment, a clip for use in securing a cast architectural element to a substrate is provided, wherein the element has a stone shell having front, end, side and rear walls defining an internal cavity, the rear walls defining a rear opening, a core is disposed in the internal cavity, a layer of mesh is disposed upon the core, and a settable filler layer is disposed upon the mesh in the rear opening, such that upon setting, the filler retains the clip in position. The clip includes a first clip portion with an eyelet, a second clip portion with at least one core engaging tooth, a transition portion between the first and second clip portions which axially displaces the first and second portions, which are parallel to each other. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a fragmentary top perspective view of the present block with embedded clip; 
         FIG. 2  is an exploded perspective view of the block of  FIG. 1 ; 
         FIG. 3  is a partially exploded view of the block of  FIG. 2 ; 
         FIG. 4  is a top perspective view of the present block partially assembled; 
         FIG. 5  is a top perspective view of the final assembly of the present block; 
         FIG. 6  is a top perspective of the block of  FIG. 6  fully assembled; 
         FIG. 7  is a bottom perspective of a clip suitable for use with the present block; and 
         FIG. 8  is a fragmentary elevation of a wall having a plurality of the present blocks attached thereto. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to  FIGS. 1-4 , a cast architectural element is generally designated  10  and is shown as an ornamental facade construction block; however other types of cast architectural elements are contemplated, including but not limited to trim pieces, moldings, baseboard moldings, mantles, wainscoting, window sills, window jams, columns, column bases, column caps, cornices, headboards, and the like. Included on the element  10  is a stone shell  12  having a front wall  14 , a pair of side walls  16 , a pair of end walls  18 , and a pair of rear walls  20  defining an internal cavity  22  (shown hidden). The rear walls  20  each have a corresponding edge  24  spaced from each other to define a rear opening  26 . It will be seen in  FIG. 1  that the edges  24  are angled inwardly so that an inner corner  28  of each edge is closer to an adjacent one of the side walls  16  than an outer corner  30 . 
     A core  32  is disposed in the internal cavity  22 , and as is known in the art, the core is made of expanded polystyrene foam (EPS) which becomes fused to inner surfaces of the stone shell  12  through the casting process. The stone shell  12  is preferably made of a cement matrix with aggregate, as described above, and may be made of marble, quartz, limestone, silica or the like, as well as mixtures of the above. Prior to further assembly, approximately ⅜-⅝ inch (0.9525-1.588 cm) of the core  32  is removed from the rear edge  24 , creating a recess  34  in the core ( FIG. 2 ). 
     Referring now to  FIGS. 2 ,  3  and  7 , at least one and preferably a pair of attachment clips  36  are placed on a rear ledge  38  formed by the end walls  18 . In total, each cast element  10  will preferably have four attachment clips  36 , a pair at the upper edge and a pair at the lower edge. However, the number and placement of the clips  36  may vary to suit the application. 
     Each clip  36  has a first portion  40  resting on the ledge  38 , extending from the shell  12  and defining at least one eyelet  42 . A second portion  44  is engaged in the core  32 . In the preferred embodiment, the engagement takes the form of at least one and even more preferably a plurality of pointed teeth  46 , which are provided in parallel rows  48 , each row having multiple teeth. It will be seen that the teeth  46  are preferably all about the same length and are provided in a length sufficient to securely engage the core  32 . In the preferred embodiment, the teeth  46  are approximately 1 inch (2.5 cm) long and are stamped from the second portion  44  and bent into an approximate perpendicular orientation thereto. However, other dimensions, fabrication techniques are contemplated depending on the application. 
     Between the first and second portions  38 ,  42  a transition portion  50  is provided which axially displaces or offsets the first and second portions, which are also preferably parallel to each other. In the clip  36 , which is preferably an integral unit, the transition portion  50  is integral with the first and second portions  40 ,  44 , being stamped from a single piece of 14 Gauge galvanized or stainless steel or material with similar strength and corrosion-resistant properties. 
     The present cast architectural element  10  further includes a layer or sheet of mesh  52  disposed upon the core and the second clip portions  44  of each of the clips  36 . It will be seen that the mesh  52  is disposed below the inner corner  28  ( FIG. 1 ). It is preferred that the mesh  52  is 2.5 ounce per square foot (0.763 kg/m 2 )galvanized expanded metal lath or the like. The weight and material of the mesh  52  may vary to suit the application. A main function of the mesh  52  is to provide a matrix for supporting a layer of settable filler  54 , which is disposed upon the mesh in the rear opening  26 . 
     Referring now to  FIGS. 1 ,  5  and  6 , the filler  54  is preferably a settable, workable material that can be troweled upon the layer of mesh  52 , and most preferably is cement-based stucco. The filler  54  is applied in a sufficient amount and consistency to become flush with an exterior surface  56  of the rear walls  20 . It is important for achieving the desired properties of the present cast architectural element  10  that the filler  54  be applied so that peripheral edges  58  engage the angled inner edges  24  of the rear walls  20  ( FIG. 1 ). Thus, upon setting, the filler  54  will bond with the shell  12 , will be supported by the mesh  52 , and will encapsulate the clips  36  as well as the core  32 . Also, the set filler  54  will be retained in position in the element  10  by virtue of the angled edges  24 . 
     Referring now to  FIG. 8 , the manner of securing the present cast architectural elements  10  to a building exterior, interior or other substrate  60  is shown. Fasteners (not shown) engage the eyelets  42  and the building substrate  60 . In addition, a layer of chemical adhesive  62  is placed behind the element  10  to enhance the action of the fastener, and also to facilitate leveling the element against the substrate  60 . Next, a sealant  64  is placed between adjacent elements  10  to prevent water entry and to simulate mortar used in conventional ornamental stone applications. 
     Thus, it will be seen that the present cast architectural building element provides a lightweight replacement for conventional ornamental stone blocks. In addition, it is relatively easy to positively attach to a building surface using conventional fasteners as well as chemical adhesive. By employing the present system for embedding the attachment clips, the clip is secured within, and becomes an integral part of the element. 
     While a particular embodiment of the embedded clip attachment for a cast architectural element has been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.