Patent Publication Number: US-6659099-B2

Title: Method for manufacturing non-seamed stone corners for veneer stone surfaces

Description:
This application claim the benefit of provisional application No. 60/306,060 filed Jul. 17, 2001. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to stone masonry, and in particular to the construction of stone surfaces and corners using veneer stone. 
     2. Background Description 
     Formerly stone is laid as a structural component or as an aesthetic cladding or veneer on houses, buildings, walls, chimneys and as paving or flooring. 
     Stone comes in different types: thin stone one-half inch to three inches thick that is either a field stone or is quarried and split to the appropriate size; and building stone, which is a three inch to nine inch thick stone that is either a field stone or is quarried and split to the appropriate size. Thin stone and building stone are generally the same stone except for their different thicknesses. 
     There are many other types of stone: flag stone, granite, marble, dimensional stone that typically comes in thin panels flat or polished. Also there are boulders and edging, none of which are of concern to the present invention. Only thin stone and building stone are of concern to the present invention. 
     The advantages and disadvantages of thin stone are as follows. Thin stone is inexpensive to buy, easy and inexpensive to lay, and easy and inexpensive to transport. However, thin stone leaves an unsightly joint on the outside corners of the wall, house, building or whatever is being laid. At the outside corners, the thickness of the stone can be readily ascertained because the thin edge of the stone is visible, which shatters the illusion of a thick (4 inch to 9 inch) stone cladding most preferred by customers. It should be noted that inside corners are not a problem, because the thin edges do not show and there is no difference in the appearance between building stone and thin stone. The difficulty is with the external corner. 
     There are two inadequate solutions in the prior art. First, building stone is laid instead of thin stone, which solves the problem of unsightly corners of thin stone. The down side of building stone is it&#39;s expensive to buy, hard and expensive to lay, and heavy and expensive to transport. 
     Second, culture or imitation stone may be used to provide an illusion of thick stone at the corners. Culture stone is made of poured and cast concrete to which is applied a thin cladding layer of simulated rock on the front and edges. Culture stone comes in a two part system. Flat stones (½ inch to 3 inch thick) laid on the wall surface and corner pieces shaped like a 90 degree “L” (½ inch to 3 inches thick) laid on the corners of the wall. Laid together, these surface and corner pieces give the illusion of thick stone, but it is light in weight compared to thick stone and it has the easy laying character of thin stone. 
     The drawbacks to this solution are as follows: culture stone costs as much per square foot of surface area as thick building stone. Culture stone can&#39;t be cleaned with commercial acid based masonry cleaners to remove mortar stains, as this would corrode the “stone” appearance and void the warranty. Culture stone can&#39;t be used in constant contact with water (ponds, swimming pools and the like), unlike real stone. Furthermore, culture stone doesn&#39;t lend itself to fit and finish as well as thin stone. Typically, thin stone is trimmed a bit with a hammer and/or flipped over to fit in various spots in a wall. FIG. 2A shows a thin stone  200  with edges  210 . Trimming the thin stone  200  reveals a new edge  220 , which has the same texture and attributes as the stone itself. Culture stone trimmed up exposes the unsightly inside of the piece since the stone look of the piece is provided by a thin coating. Culture stone can&#39;t be flipped over to fit a space since the coating is only on the front. FIG. 2B shows a culture stone  250  with edges  260 . Trimming the culture stone  250  reveals a new edge  270 , which does not have the cladding of edges  260 . Instead, the edge  270  shows a cladding layer  275  (not shown to scale) formed over concrete  280 . 
     It is to be noted that another potential solution is not workable. Culture stone corners cannot be used with thin stone walls because the texture of the culture stone cladding is noticeably different from thin stone, and makes the corners unsightly on that account. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a way of constructing outside corner stones for veneer stone surfaces which hide the seams which appear when thin stone veneer is used at the corners. 
     Another object of the invention is to provide for efficient use of building stone by making two outside corner stones from a single building stone. 
     The invention is implemented as follows. On a typical wall utilize thin stone to lay the field of the wall. Then cut 90 degree corners out of building stone squares and rectangles so as to leave a corner piece ½ inch to 3 inch thick to match the thickness of the thin stone on the field of the wall. Lay these on the corners of the wall. This will give the illusion of a thick building stone wall with nearly the low cost and easy laying of thin stone; the wall with these corner pieces costs much less than a wall laid with culture stone, and is nearly as light. 
     In one embodiment, the method of the invention constructs non-seamed stone corners for first and second thin stone walls of thickness T 1  and T 2 , respectively, joined at right angles at an external edge, by selecting a building stone having a height H, a depth D and a width W, the building stone having top and bottom surfaces H 1  and H 2 , respectively, front and back surfaces D 1  and D 2 , respectively, and left and right surfaces W 1  and W 2 , respectively. Then a first cut is made in the selected building stone, the plane of the first cut being parallel to the plane of surface W 1  and extending to a uniform depth from surface H 1 , such that the distance between the plane of the first cut and the plane of surface W 1  is T 1 , and such that the uniform depth is equal to (H−T 2 ). Then a second cut is made in the building stone, the plane of the second cut being parallel to the plane of surface H 1  and extending to a second uniform depth from surface W 2 , such that the distance between the plane of the second cut and the plane of surface H 2  is T 2 , and such that the second uniform depth is equal to (W−T 1 ). 
     These two cuts separate from the building stone a residual piece, leaving a corner stone. In a further embodiment of the invention, the residual piece is large enough for use in making a second corner stone. The residual piece is re-oriented as a workpiece so that neither the left surface nor the bottom surface is formed by either the first cut or the second cut, since the left and bottom surfaces (as viewed in preparation for the initial cut) will show on the corner and should be a natural stone surface rather than a saw cut surface. Three such re-orientations are possible. After such re-orientation, the residual piece will have a height H′, a width W′ and a depth D′. The residual piece will also have top and bottom surfaces H′ 1  and H′ 2 , respectively, left and right surfaces W′ 1  and W′ 2  respectively, and front and back surfaces D′ 1  and D′ 2 , respectively. Essentially the same method used to create the first corner stone is then used upon the re-oriented residual piece to create a second corner stone. A third cut is made in the residual piece, the plane of the third cut being parallel to the plane of surface W′ 1  and extending to a third uniform depth from surface H′ 1 , such that the distance between the plane of the third cut and the plane of surface W′ 1  is T 1 , and such that the third uniform depth is equal to (H′−T 2 ). A fourth cut is made in the residual piece, the plane of the fourth cut being parallel to the plane of surface H′ 1  and extending to a fourth uniform depth from surface W′ 2 , such that the distance between the plane of the fourth cut and the plane of surface H′ 2  is T 2 , and such that the fourth uniform depth is equal to (W′−T 1 ). 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects, aspects and advantages will be better understood from the following detailed description of a preferred embodiment of the invention with reference to the drawings, in which: 
     FIGS. 1A through 1G are a sequence of drawings showing how thick building stone is cut in accordance with the invention. FIG. 1A shows a stationary saw assembly. FIG. 1B shows a thick stone working piece in the saw assembly. FIG. 1C shows the working piece in the saw assembly after a first cut. FIG. 1D shows the working piece rotated in preparation for a second cut. FIG. 1E shows the rotated working piece in the saw assembly. FIG. 1F shows the working piece in the saw assembly after a second cut. FIG. 1G is a perspective diagram of a working piece showing both cuts and labeling the faces and dimensions of the working piece. 
     FIG. 2A shows a trimmed edge of thin stone. FIG. 2B shows a trimmed edge of culture stone. 
     FIG. 3 is a series of cutaway drawings showing a top view of wall corners constructed from thin stone (FIG.  3 A), thick stone (FIG.  3 B), thin stone with corners cut in accordance with the invention (FIG.  3 C), and culture stone (FIG.  3 D). 
     FIG. 4 is a series of perspective drawings showing an outside view of wall corners constructed from thin stone (FIG.  4 A), thick stone (FIG.  4 B), thin stone with corners cut in accordance with the invention (FIG.  4 C), and culture stone (FIG.  4 D). 
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION 
     Stone corners in accordance with the invention can be made with two types of common masonry saws. The stationary saw  100  as shown in FIG. 1A can cut either wet or dry. Stone can also be cut with a hand held saw (not shown). Utilizing recent breakthroughs in stone saw blade technology, the stationary saw is the easier, safer and faster saw for implementing the invention. As shown in FIG. 1A, the stationary saw assembly includes a motor  116  connected by a drive arm  114  to saw blade  110 , which is protected by a saw blade safety cover  112 . The saw blade  110  is adjusted to a desired vertical height by rotating platform  126  about axis  127  and tightening adjustable brace  128 . The saw blade  110  remains stationary during the cutting process. A workpiece (shown as item  130  in FIG. 1B) is placed on table  118  abutting front stop  120 . Table  118  has a groove  122  to allow cutting through a workpiece. 
     Now turning to FIG. 1C, using a typical 14 inch saw blade machine (stationary saw assembly  100 ), a reasonably square or rectangular stone (e.g. workpiece  130 ) is selected between 6 inches and 3 inches in height, 6 inches and 3 inches in width, and 10 inches and 3 inches in length. The saw blade  110  is set at a height above the table  118  equal to the thickness of the thin stone being used to lay the field of a wall (for example, 1½ inches above the table). The stone  130  is placed on the table  118 , which is movable front to back (shown by arrow  119 ) along the plane of the saw blade  110 , square to the saw blade with the length of the stone  130  parallel to the blade  110 . The stone  130  is moved side to side along the front stop of the table  118  until the blade  110  would engage the stone the desired distance (for example, 1½ inches) from the left parallel face of the stone  130  when cutting commences. The saw motor  116  is turned on and the table  118  with stone  130  abutting front stop  120  is pushed entirely through the blade  110  and then pulled back to the start point. The motor  116  is then turned off. At this point stone  130  (as shown in the cutaway of FIG. 1C) has a cut  135  which leaves a stone thickness  142  (for example, 1½ inches) to the left of the cut  135  and a stone thickness  140  (for example, 1½ inches) below the cut  135 . The thickness  140  and thickness  142  correspond to the thickness of the thin stone used for the field of the wall being laid. 
     The stone  130  is then rolled to the left as shown in FIG. 1D so the former left facing face of the stone (not shown) is now face down on the table, still against the stop  120  and the length of the stone  130  is still parallel to the saw blade  110 . Horizontal edge  150  is now vertical, vertical edge  152  is now horizontal, and cut  135  is now perpendicular to saw blade  110 . The rotated stone  130  is shown in FIG.  1 E. In preparation for the second cut, the stone  130  is moved side to side along the front stop  120  of the table  118  until the blade would engage the stone the desired distance (for example, 1½ inches) from the right parallel face of the stone when cutting commences. Turning now to FIG. 1F, the saw motor  116  is turned on and the table  118  with stone  130  abutting front stop  120  is pushed entirely through the blade  110  and then pulled back to the start point. The motor  116  is then turned off. The stone  130  now has a second cut  145 , leaving corner  160 . Sandblast the backside of the corner stone  160  (i.e. the surfaces formed by cuts  135  and  145 ) to roughen them so mortar can adhere to the stone. 
     The result of the cutting process is shown in a perspective drawing of the stone  130  in FIG.  1 G. The stone  130  has height H, width W and depth D. Viewed in an orientation in preparation for the first cut  135 , the top and bottom surfaces are labeled as H 1  and H 2 , respectively. Left and right surfaces are labeled W 1  and W 2 , respectively. Front and back surfaces are labeled D 1  and D 2 , respectively. After second cut  145  the stone is separated into two pieces, the corner stone  160  and the residual piece  170 . First cut  135  is at a distance T 1  from left face W 1  to a uniform depth of (H−T 2 ) from top surface H 1  toward bottom surface H 2 . Second cut  145  is at a distance T 2  from bottom surface H 2  to a uniform depth of (W−T 1 ) from right surface W 2  toward left surface W 1 . 
     The stone corner  160  may now be laid in the wall, as may be seen with reference to FIG. 3C, which is a cutaway view from the top of the wall. Thin stones  340  have been laid along the field of the wall, with mortar  302 . The new stone corner  160  is shown laid as item  345 . Although only the top edge  347  and a portion of the back side  348  appears in the FIG. 3C, it is to be noted that the stone goes around the corner  305 . It should also be noted that if the waste piece which is cut away, leaving corner piece  160 , is itself a reasonably large square or rectangular stone (as described above), another corner piece can be constructed, provided the first and second cuts are such that neither of the two outer surfaces of the resulting corner piece (that is, the two surfaces which are visible when the corner is laid) were created by cuts  135  or  145  from the first corner piece. In this event, there is an additional economy from creating two corner pieces from a single building stone. 
     A thin stone wall having corner pieces in accordance with the invention may be contrasted with the prior art alternatives. A cutaway view from the top of the wall for the conventional thin stone veneer is shown in FIG.  3 A. Thin stones  310  have been laid along the field of the wall, with mortar  302 . A corner is made from thin stones  320  and  325 , but it will be seen that there is visible on the corner  305  an edge  327  and a gap  328  which must be filled with mortar. A cutaway view from the top of the wall of a wall made with building stone in shown in FIG.  3 B. Building stones  330  have been laid along the field of the wall, with mortar  302 , and the corner is made from building stone  335 . There is no concern about an illusion of building stone, because the wall is in fact constructed of building stone. 
     FIG. 3D shows a cutaway view from the top of a wall constructed with culture stone. Culture stones  350  have been laid along the field of the wall, with mortar  302 . A Culture stone corner  355  is laid over corner  305 . The back side  357  of the culture stone does not show from the front view of the wall. The cutaway perspective view shows the thin cladding  360  (not shown to scale) on the surface of the culture stones  350  and  355 . The cutaway also shows, on the wall side of the culture stones  350  and  355  the interior concrete  370  over which the cladding  360  is formed. 
     Turning now to FIG. 4C there is shown the external appearance of a wall constructed with corner pieces in accordance with the invention. Thin stones  440  are laid along the field of the wall, with corner pieces  445  set along the vertical corner edge  446 . Note that the corner edge  447  of corner piece  445  is seamless. It should also be noted that a similar seamless corner appearance applies to a wall laid with building stone, as shown in FIG.  4 B. Building stones  430  are laid along the field of the wall, and are also used as corner pieces  435  along vertical corner edge  436 . Note that the corner edge  437  of stone  435  is seamless, being a solid building stone. Similarly, a wall laid with culture stone will have a seamless vertical corner edge, as shown in FIG.  4 D. Culture stones  450  are laid along the field of the wall. Culture corner pieces  455  are laid along vertical corner edge  456 . The corner edge  457  of culture corner piece  455  has a seamless appearance. 
     In contrast, the vertical corner edge of a wall laid with thin stone has a noticeable and undesirable seam, as shown in FIG.  4 A. Thin stones  410  are laid along the field of the wall. At the corner a thin stone  425  is laid on one wall and a thin stone  420  is laid on the other wall. The edge  427  of thin stone  425  is visible on the corner. There is a mortar joint  428  between edge  427  and thin stone  420 . The combination of edge  427  and mortar joint  428  along the vertical corner edge, forming an obvious and unsightly seam. 
     The invention improves upon all the prior art alternatives. It provides a seamless corner edge where two thin stone walls join. By using thin stone for laying the field of the wall, there is an advantage over building stone walls because thin stone is lighter, and therefore is less expensive and easier to transport and lay. And thin stone with cut corner pieces is more versatile than culture stone because it can be used in water, can be trimmed and flipped to fit in various spots in a wall, and can be cleaned with commercial acid based masonry cleaners. 
     While the invention has been described in terms of a single preferred embodiment, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the appended claims.