Abstract:
A method of forming a wall unit having a veneer face is disclosed. Initially, a pair of side wall panels and a pair of end panels are mounted substantially upright. Stones or other suitable material are set sequentially in a horizontally disposed course using at least one of the panels. Additional courses of stones or other material may then be stacked upon the initial layer until the desired height is attained. The interior volume of the apparatus is left substantially empty, and is then filled with a binding material. The binding material binds the courses&#39; components together and integrates the individual courses into a single cohesive unit. The wall and end panels are removed and the unit is removed for subsequent installation.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     This invention relates generally to a method and apparatus for molding wall units, and in particular to constructing a wall unit having layered discrete veneer components, such as stones, on the outer surface. 
     2. Background Art 
     Various methods of forming a stone veneer on a single side of a wall unit have heretofore been performed. In one of the related art techniques, a plurality of stones are arranged face-down, forming a single horizontal layer, upon a base surface as discussed in U.S. Pat. No. 1,856,906. 
     The inherent disadvantage of this method is that, since it entails laying the veneer stones horizontally across the bottom of the form, it is limited to producing a stone veneer on only a single surface of the wall unit. Therefore, if a construction design calls for a wall unit having a stone veneer on more than one side, two wall units would have to be constructed separately and positioned back-to-back to produce the desired fixture. Similarly, if a design specified an end unit with a veneer on two or more sides, this would require two or more separate pours, with the attendant increase in manufacturing, shipping, and construction costs. 
     A second related art method is to pre-cast the core with a plurality of discrete attachment anchors (e.g. slots, ties, etc.) and then create the veneer on the previously finished core using a story pole, sandwiching, or other known technique. See, for example, U.S. Pat. No. 5,761,876 to Keady. This process requires at least two separate casting steps or “pours.” 
     Thus, there exists a need for a method which can be used to produce a stone veneer on multiple sides of a wall unit in an efficient and cost effective manner, for instance, in a single pour of concrete. There also exists a related need for a method which can produce stone veneers on multiple curved, sloped, or angled wall unit surfaces. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method for forming a wall unit using a molding technique, comprising: operationally attaching a plurality of panels in an upright manner; arranging two or more layers of discrete veneer components adjacent one of said plurality of panels; filling said volume with a binding material; and subsequent to curing of the binding material, removing said panels. 
     A wall unit form comprising a first surface; a second surface operatively attached to said first surface; end surfaces operatively attached to said first and second surfaces thereby forming an upright form and opposing sides; and optionally, a pocket structure operatively attached to at least one of said surfaces. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, according to common practice and for the sake of clarity, the various features of the drawings are not drawn to scale. On the contrary, the dimensions of the various features may have been arbitrarily expanded or reduced. Included in the drawings are the following figures: 
     FIG. 1 is an end view of a wall unit form showing mounting of a pair of hinged or removable side panels and an end panel according to a preferred embodiment of the present invention; 
     FIG. 2 is a plan view of the wall unit form of FIG. 1 according to a preferred embodiment of the present invention; 
     FIGS. 3A,  3 B, and  3 C depict front, side and top views, respectively, of a wall unit produced according to a preferred embodiment of the present invention; 
     FIG. 4 depicts a perspective view of a double stone-face wall unit produced according to a preferred embodiment of the present invention; 
     FIG. 5 depicts a detail plan view of the seamless joint between two wall units according to FIG. 4; 
     FIG. 6 depicts a plan view of a double corner end unit according to one possible embodiment of the present invention; 
     FIG. 7 depicts a plan view of a left or right corner end unit with an integral pocket formed therein according to one possible embodiment of the present invention; 
     FIG. 8 depicts a plan view of a left or right end unit according to one possible embodiment of the present invention; 
     FIG. 9 depicts a plan view of a double corner end unit with nonlinear and tapered surfaces according to one possible embodiment of the present invention; and 
     FIG. 10 depicts a perspective view of a wall unit form with extensions in place to form a base or footing according to one possible embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention generally provides a method for forming wall units, and in particular to a method for constructing a wall unit having layered discrete veneer components on the outer surface of at least one side. 
     The present invention further discloses the wall unit form which is utilized in the novel production method disclosed herein. 
     The term “stone” veneer is used throughout the description of the invention solely for ease of communication. There is no intent to limit the veneer material to stone. Rather, any discrete building component may be employed in the method described herein. 
     While this invention is susceptible to embodiment in many different forms, there is shown in the drawings, and will be described in detail, a preferred embodiment of the invention. It should be understood, however, that the present disclosure is to be considered as an exemplification of the principles of this invention and is not intended to limit the invention to the embodiment illustrated. 
     1. The Wall Unit Form 
     Referring to FIG. 1, this figure shows an end view of a wall unit form  10  with first and second side panels  12 ,  14  and a first end panel  16 . All of these panels, and second end panel  18  (FIG.  2 ), are mounted to each other upon the ground or upon a base panel  20 , according to the present invention. The side panels  12 ,  14 , as well as the first and second end panels  16 ,  18  can be hinged (as shown) or removably attached. An advantage of the movable panels  12 ,  14 ,  16 ,  18  is that they facilitate entry into the wall unit form  10  during various production operations as will be discussed in the Method section below. The wall unit form  10  may also include a cavity to accommodate material that will form a base or footing if the footing is to be molded as an integral piece of the wall unit  50 . The base or footing cavity can be formed by extensions  84  that are attached, as necessary, to movable panels  12 ,  14 ,  16 ,  18  (FIG.  10 ). The extensions  84  may be of any required contour, and these are capable of producing a base having either squared or radiused corners and ends. 
     The wall unit form  10  is also adaptable to receive a form liner. The form liner is operationally attached to the interior of panels  12 ,  14 ,  16 ,  18  and facilitates the desired alignment of irregularly-shaped veneer components, in a random horizontal and vertical orientation, against the form liner. The form-liner is a smooth sheet of material such as, inter alia, wood, metal, plastic, or the like, which covers and protects the interior surface of panels  12 ,  14 ,  16 , or  18 , and which can be used to reduce the overall size of a finished wall unit. Thus, a single wall unit form  10 , can be combined with a variety of different size form liners, to produce different size wall units. A form liner, as herein described, is thus distinguished from the “guide form” known in the related art (See, for example, U.S. Pat. No. 1,809,504 to Carvel, FIG. 18, element 24; and FIG. 26, element 32). The guide forms of the related art are affixed to the insides of the form panels to provide regular intervals between discrete components. 
     The base panel  20  is further adapted to receive a pocket forming structure such as a footing loop pocket structure  24 . Use of the footing loop pocket structure  24  enables formation of a shear key or footing loop pocket  48  (FIGS. 3A,  3 B) in the bottom surface of the wall unit  50 . 
     The connecting loop pocket structure  22  (FIG.  2 ), the footing loop pocket structure  24  (FIG.  1 ), and the lifting loop pocket structure  56  (FIG. 1) are structures that are temporarily and removably placed upon the panels  12 ,  14 ,  16 ,  18  forming the wall unit form  10  to create longitudinal voids in the finished wall unit  50 . These voids are useful for accommodating means for interlocking adjacent wall units  50  as will be discussed herein below. The loop pocket structures (connecting, footing, and lifting,  22 ,  24 ,  56 , respectively) may be formed on any surface of the wall unit, but are typically formed on the ends, top, or bottom of the wall unit  50 . The loop pocket structures  22 ,  24 ,  56  are typically vee-shaped, but they may have any another cross-sectional shape which may be more suited to a particular application. Finally, the loop pocket structures  22 ,  24  may be fabricated of metal, wood, plastic, or any other material having the structural properties required by this process. 
     As shown in FIG. 2, the wall unit form  10  can receive a connecting loop pocket structure  22  at either or both ends. The connecting loop pocket structure  22  is attached to either or both end panels  16 ,  18 . Use of the connecting loop pocket structure  22  allows a connecting loop pocket  46  (FIG. 3A) to be formed on the ends  52 ,  54  of the wall unit  50 . 
     Referring now to FIG. 3, there are shown several views of a wall unit  50 . FIG. 3A presents a front view of a wall unit  50 , showing a connecting loop pocket  46  at each end of the wall unit  50 . Connecting loop rods  30  extend into the connecting loop pockets  46  from the interior of the wall unit  50 . Similarly, lifting loop rods  28  extend into the lifting loop pocket  58 , and provide a means for lifting the wall unit  50  when so required. The connecting loop rods  30  and the lifting loop rods  28  are typically formed from reinforcing rods, commonly known as rebar, of sufficient size and quantity as dictated by the application. 
     A footing loop pocket  48  is shown formed along the bottom of the wall unit  50 . Footing loop rods  70  may be formed that extend into the footing loop pocket  48 , in mirror image fashion compared to the lifting loop rods  28  and the lifting loop pocket  58 . The footing loop rods  70  may be used to anchor the wall unit to a concrete footing  36  or other base, typically by attachment to a footing-to-unit loop rod  64  (FIG.  4 ). 
     Also shown is a chaseway  32  which can accommodate pipes, culverts, wiring, drainage, unit lifting means, windows, doorways, or the like. The chaseway  32  may be placed at other locations within the wall unit  50 . While only a single chaseway  32  is shown, a plurality of chaseways  32  may be employed as necessary. 
     FIG. 3B shows a side view of a wall unit  50  presenting a second view of many of the features described above. Also shown here are a plurality of the stone veneer pieces  26 . The veneer pieces  26  comprise the sides of the wall unit  50 , while the inner space between the veneers is occupied by a binding or cementation material  34 . The binding or cementation material  34  may be cement, concrete, mortar, or other suitably binding material such as certain foams and plastic compounds. 
     FIG. 3C depicts a plan view of the wall unit  50 , which further presents the features discussed above. 
     The wall units  50  are not limited to having a stone veneer  26  on one or two sides. They may have a stone veneer  26  on any number of sides. For instance, FIG. 6 shows a double corner end unit  72  which has a rectangular shape, and a stone veneer covering four sides. A left or right end unit  76  may also be formed (FIG.  8 ). Further, the connecting loop pocket  46  need not be placed at an end of the wall unit  50 . It may be placed on a side to yield the left or right corner end unit  74  shown in FIG.  7 . Finally, the wall unit form  10  is not limited to a rectangular shape. The sides may be angled or curved to meet any design criteria. FIG. 9 depicts a composite wall unit  78  which includes both of these features. 
     2. Method of Making the Wall Unit 
     The wall unit  50  is produced using the wall unit form  10  illustrated in FIGS. 1 and 2. 
     As a first step, hinged or removable first and second surfaces or side panels  12 ,  14  are removably attached to first and second end surfaces or panels  16 ,  18 . The panels  12 ,  14 ,  16 , and  18  may also be affixed to an optional surface base or panel  20  at this time. However, depending on the size and configuration of the wall unit  50  that is to be constructed, either end panel  16 ,  18  may be left off to facilitate access to the interior of the wall unit form  10 . The wall unit form  10  may commonly have a rectangular shape, but could have any desired shape, including angled sides, curved sides, or sloped sides (FIG.  9 ). 
     Once the desired panels are in place, removable structures may be affixed to the panels. These structures function as connecting loop pocket structures  22 , footing loop pocket structures  24 , or lifting loop pocket structures  56 , depending on their placement within the form. 
     Next, individual stones are placed along the bottom of at least one side panel. Successive layers of stones are stacked upon the initial layer, thereby forming a stone veneer  26 . Smaller pieces of stone or non-stone material may be used as shims  82  (FIG. 3B) to ensure a specified gap or joint size between the stones. Alternatively, the stones may be stacked with no spaces between them. The stone veneer can also be built to accommodate chaseways, drainage pipes, culverts, windows, doorways, lighting fixtures, etc., as required. A stone veneer may be built against a single wall, or preferably, on more than one wall at the same time. For those units requiring that there be no visible seams between wall units  50 , removable indentation blocks  80  (FIG. 4) are placed in appropriate locations in the stone veneer  26 . 
     Once installation of the stone veneers  26  is completed, reinforcing rods are added as necessary to provide structural integrity, and to provide lifting loop rods  28 , connecting loop rods  30 , and footing loop rods  70 . 
     Now that the discrete components of the wall unit  50  are in place, any panels  12 ,  14 ,  16 , and  18  which were not installed earlier are attached to complete the form. The wall unit form  10  is then filled with a binding or cementation material  34 . This binding material  34  is poured into the wall unit form  10  through the exposed upper area. 
     The binding material  34  may be textured or colored, and may be a mortar, cement, concrete or similar mixture, or a plastic or foam compound. The binding material  34  is then allowed to cure. 
     In some architectural applications it will be desirable for adjacent wall units  50  to appear as if there is no joint between them. In such cases, a temporary, removable indentation block  80  is placed at any suitable location in the stone veneer  26  array prior to addition of the binding material  34 . The indentation block  80  is removed after curing, thus leaving a void in the stone veneer  26 . A seamless joint can then be accomplished using a stone crossing joint  38  (FIG. 5) which is placed across the vertical joint between the units  50  utilizing the space vacated by the removable indentation block  80  (FIG.  4 ). Similarly, horizontal joints can be disguised between stacked wall units  50 . 
     The wall unit  50  may also be formed with a footing or base  36 , wherein the footing  36  which is poured as an integral portion of the wall unit  50  at the same time that the remainder of the wall unit  50  is poured. 
     The foregoing specification is intended as illustrative and is not intended to be taken as limiting. Still other variations within the spirit and scope of this invention are possible and will readily present themselves to those skilled in the art.