Abstract:
A decorative column comprising a rigid center post, a plurality of pre-cast pieces with each piece having a hole extending therethrough so the pre-cast piece slides onto the center post and remains in place on the center post. Each pre-cast piece being stacked upon another pre-cast piece, the pre-cast pieces being of a predefined shape, and a compressible center core liner filling a portion of the hole of the pre-cast piece. The compressible center core including a cutout shape consistent with the cross sectional shape of the rigid center post thereby allowing passage of the center post through the compressible center core.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of the filing date of a provisional application with Ser. No. 61/305,289 which was filed on Feb. 17, 2010, the disclosure of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The disclosed subject matter is directed to the production of pre-cast blocks for constructing modular columns. 
     BACKGROUND 
     Decorative stone columns are widely used by homeowners and businesses for a variety of purposes such as the monuments at the entrance of a driveway, as supports between fence sections, as a base for a statue, and as pillars at the entrance to a building to name just a few uses. The construction of decorative stone columns normally requires the services of a skilled mason and the utilization of specialized masonry tools. The average individual does not typically have the necessary tools or requisite skill for constructing appropriate concrete forms or for completing decorative stone column construction. As a result, most decorative stone columns are usually constructed by a skilled mason and at a high cost. Producing a high quality, durable and aesthetically pleasing column at a reasonable cost can be accomplished with the assistance of modular column construction as is outlined below. 
     SUMMARY 
     The present invention pertains to the construction of a decorative column and the method of producing the modular blocks that comprise the decorative column. The column comprises a rigid center post surrounded by a plurality of modular blocks. Each modular block has a hole extending through it so the block can fit onto the rigid center post and remain fixed in place on the post. Each modular block is stackable upon another block of similar construction. The present invention pertains to a method for not only producing the modular blocks with compressible inserts but also the erecting of a decorative column that is capable of accommodating ground heaving due to freezing temperatures and thermal expansion which is particularly important, for example, when the column is utilized to support fence sections. 
     The method comprises the steps of producing a flexible mold for forming the modular blocks, positioning a compressible insert into the mold, filling the open area created by the walls of the mold and the exterior surfaces of the compressible insert with a lightweight cementitious material, waiting for the cementitious material to cure and then removing the modular block from the flexible mold. 
     Once the modular blocks with the compressible inserts are removed from the mold they are positioned onto the rigid center post so that the compressible insert center opening is aligned with the rigid post and can slide down the post to either the ground or atop another modular block. The process of placing the modular blocks on the center post can be repeated as necessary to produce a decorative column of the desired height. 
     The compressible inserts are instrumental in reducing the weight of the modular blocks as the inserts are preferably comprised of materials such as EPS foam or cellular PVC to name but a few available options. In addition, the compressible inserts facilitate placement of the modular blocks on the rigid center post particularly for posts of a substantial height as the compressible and flexible material will not bind against the post as the blocks are lowered into position on the post. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a three rail fence constructed with modular columns; 
         FIG. 2  is a perspective view of a panel fence constructed with modular columns; 
         FIG. 3  is a perspective view of a center post of a modular column being constructed with pre-cast ornamental blocks; 
         FIG. 4  is a plan view of an embodiment of a pre-cast block without side slots utilized in a modular column; 
         FIG. 5  is a plan view of an embodiment of a pre-cast block with single dimension side slots utilized in a modular column; 
         FIG. 6  is a plan view of an embodiment of a block with dual dimension side slots utilized in a modular column; 
         FIG. 7  is a plan view of an embodiment of a block with single dimension side slots utilized in a modular column; 
         FIG. 8  is a cross sectional view of  FIG. 2  revealing the interior features of a modular column; 
         FIG. 9  is a perspective view of an empty mold with a center post for forming a block for use in a modular column; 
         FIG. 10  is a perspective view of a mold showing a compressible insert surrounding the center post used for forming a block for use in a modular column; 
         FIG. 11  is a perspective view of a mold showing the addition of a cementitious material to the open area of the mold for forming a block for use in a modular column; and 
         FIG. 12  is a perspective view of a mold showing the cementitious material leveled at the top of the mold for purposes of forming a block for use in a decorative modular column. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings wherein like reference numerals refer to similar of identical parts throughout the several views.  FIG. 1  reveals a fence section comprised of two modular columns  10  connected by fence rails  54 .  FIG. 3  details the process by which a modular block  58  is lowered being lowered into position over a post  12  onto several pre-cast blocks  14 ,  16 ,  18  already in position. Pre-cast blocks can be used to efficiently and with high aesthetic appeal produce columns  10  for various embodiments of a rail fence such as seen in  FIG. 1  as well as for various embodiments of a panel fence such as seen in  FIG. 2 . Numerous other embodiments and uses of columns utilizing this modular pre-cast block technology are also contemplated and are only limited by the imagination. 
     The production of a pre-cast block  58  begins with the use of a flexible mold  20  such as one produced from silicone and as depicted in  FIG. 9 . The mold  20  includes four sides  22 A, B, C and D a center post  24  as well as textured interior walls  26 . The textured interior walls  26  are intended to replicate on the finished modular block a stone face including a desirable and contrasting coloration. Prior to the addition of any cementitious material into the mold  20  the textured interior walls are coated with a coloration mixture of mineral iron oxides, cement, water and an acrylic modifier. The coating is applied consistent with the stone facing molded into the interior walls  26  so as to give the impression that the stone faces are of varying color as might be created by a mason using natural stone. Varying the mineral iron oxides content allows different colors to be formulated to satisfy customer preferences. This coloration mixture may be hand applied to specified portions of the interior wall. Alternatively, automated techniques may also be employed such as the use of robotic systems to apply the coloration mixture. 
     Once the subset of the textured interior walls  26  are coated with the above referenced mixture a compressible insert  28  is positioned over the center post  24  as shown in  FIG. 10 . The compressible insert  28  is lightweight, and preferably comprised of materials such as EPS foam or cellular PVC. The insert  28  includes an upper surface  32 , and creates an interior space  33  that will prevent the intrusion of cementitious material and also includes a plurality of exterior walls  34 . The insert upper surface  32  is preferably at the same elevation and not above the upper surface  36  of the textured interior walls  26 . 
     Once the compressible insert  28  is secured in position over the center post  24 , the open space  38  between the mold walls  26  and the exterior walls  34  of the compressible insert  28  is filled with a cementitious material  40  as seen in  FIG. 11 . The cementitious material  40  is preferably a light weight wet cement that readily flows to fill the open space  38 . An exemplary mixture of cementitious material would comprise an expanded slate lightweight concrete, such as Stalite™, a dry pigment, aggregates and water combined to form a flowable, lightweight mixture. 
     Once the open space  38  is completely filled the mold  20  is vibrated to remove voids from the cementitious material  40 , allow for settling and to facilitate the movement of the coloration mixture painted onto the mold interior walls  26  into the cementitious material  40  instead of remaining at the surface thereby giving a three dimensional penetration of the coloration mixture into the block and improving the weatherability of the block&#39;s surface coloration. In addition, as best seen in  FIG. 12 , the cementitious material  40  is leveled at the upper surface  36  to create a smooth even surface that facilitates the stackability of the blocks when the cement is cured. 
     In about twelve hours the cementitious material is fully cured and the block, along with the compressible insert, can be removed from the mold  20 . Manipulation of the flexible mold  20 , either manually by overturning the mold and popping out the block as is well known in the art, or by injection of air into an orifice in the mold bottom effectively inverting the silicone mold, will facilitate release of the block from the mold  20 . Because the cementitious material  40  permeates the pores of the exterior walls  34  of the compressible insert  28 , the insert is securely bound to the cementitious material and will not separate during use. 
     As seen in  FIGS. 4 through 7 , alternative embodiments of the block may be cast in the mold  20  with or without slots.  FIG. 4  reveals a standard block  42  without slots that would properly be employed, for example, as shown at the lowermost block  18  in the column in  FIG. 3 . This lowermost slotless block  18  would typically be employed in a column utilizing between one and four fence rails, such as exemplified in  FIG. 1 . 
     An alternative block embodiment as depicted in  FIG. 5  reveals a block  50  with slots  52  on opposed sides of the compressible insert  28 . These opposing slots  52  serve to hold rails  54  in position as is best seen in  FIG. 1 .  FIG. 3  also serves to highlight how the slot  52  of block  58  integrates with the slot and block  14  positioned immediately below it in the column to create an opening for securing the rail  54  in position. It will be readily apparent to one versed in the construction of columns that the placement of the slots  52  in a modular block  10  may be offset by 90 degrees, instead of 180 degrees, should a block be needed for a corner column with fence rails extending outwardly at 90 degrees instead of 180 degrees. In addition, a block may have only a single slot  52  should a column be needed that is adjacent a building or other structure and the rails need only extend in a single direction. 
       FIG. 6  depicts a third embodiment of a block  60  that is utilized in the construction of a panel fence such as that shown in  FIG. 2 . The narrower and shorter slot  62  serves to secure in place the edge of the entire height of the fence panel  67 . The configuration of this slot  62  can also be viewed in cross section in  FIG. 8  which shows four separate blocks  61 A,  61 B,  61 C and  61 D positioned at the top of the column. Block  61 A serves as a capping block and includes no slots since the fence panel does not extend upwardly to that height. Block  61 B includes an upper exterior surface  65  with no slot and a lower portion with a slot  64 . The slot  64  on block  61 B, in conjunction with slot  64  in block  61 C serves to secure one end of the upper rail  66 , as best seen in  FIG. 2 , in position within the column. Block  61 C also includes a small slot  62  that is intended to facilitate securing the top portion of the panel  67  in position. Finally, block  61 D includes only a small slot  62  but no larger slot  64 , such as that depicted in  FIG. 7 . The configuration of block  61 D is repeated on blocks lower in the column until reaching the lower rail  68  where a similar configuration of blocks is utilized to support the rail  68  and the panel  67  as seen at the top of the column with blocks  61 B and  61 C. The dimensions of the slots  62 ,  64  may be tailored to any preferred dimension during production to suit the specific dimensions of the fence rails  66 ,  68  and panels  67  that are being utilized. To produce slots of the desired dimension one or more inserts are positioned within the mold prior to introduction of the cementitious material  40  or the molds may have the inserts already included. Whether specifically designed into the mold for purpose of occluding the presence of the cementitious material or removable inserts are positioned within the mold  20 , once the cementitious material  40  has been cured the slots are formed into the finished block and they are ready for column construction. 
     The various embodiments of the present invention may be utilized to create a structurally sound and aesthetically pleasing column that can stand alone or be incorporated into a fence of a wide range of configurations including rail fences or panel fences. The use of pre-cast blocks  58  with their aesthetically pleasing exterior surfaces, preconfigured slots and lightweight but structurally rigid material greatly facilitates the construction of the columns. Turning again to  FIG. 3 , a rigid center post  12  is placed into the ground or secured by some other means so that it stands in a substantially vertical orientation. The center post  12  is preferably a vinyl composition post because of its resistance to weathering and insects, but may be of any sturdy material such as wood, metal or concrete. Additionally, the center post  12  can be of a wide range of dimensions such as 5 inches square or 3 inches square. Alternatively a rectangular of circular configuration for the rigid center post  12  also may be employed. The center post  12  must, however, be of only slightly lesser dimensions than the hole dimension of the compressible insert  28  so that proper alignment of the pre-cast blocks on the modular column  10  can be accomplished. 
     As seen in  FIG. 3 , once the center post  12  is secured in a substantially vertical orientation, the central opening  33  of the pre-cast block&#39;s  58  compressible insert  28  is aligned over the center post  12 . The first pre-cast block  18  to be installed is then moved onto the lowermost support surface which will either typically be a ground surface or a prepared level surface such as concrete. The process of placing additional pre-cast blocks on the column is greatly simplified with the use of a compressible insert  28 . The compressible insert material is soft and pliable and therefore will not bind against the center post  12  because of interference between the insert  28  and the post  12 . Moreover, as noted above, because of the light weight of the compressible insert and the fact that it occupies a significant percentage of the block interior volume that otherwise would be occupied by cementitious material  40  the pre-cast block weighs far less than a pre-cast block constructed without a compressible insert  28 . The nominal weight of a pre-cast block greatly facilitates the construction of a decorative modular column as placement of a pre-cast block with a compressible insert onto a center post  12  requires lesser physical exertion than installation of blocks comprised entirely of cementitious material  40 . 
     As further seen in  FIG. 3 , a multitude of modular blocks  14 ,  16 ,  18 ,  58  may be placed onto the rigid center post  12  to create a decorative column of any desired height depending upon how the columns is to be employed, for example, as a fence post, a support column or a mailbox stand. If building a fence rail column then, as previously discussed, slots  52 ,  62 ,  64  may be configured to satisfy the dimensional requirements of the fence rails and panels. Advantageously, no mortar need be placed between the pre-cast blocks to secure them in position as the blocks simply reside one atop the other creating a seamless textured stone exterior along the entire length of the column. Also advantageously, the compressible insert  28  greatly facilitates the resiliency and longevity of the decorative column  12  in areas where there is heaving of the ground due to the freeze-thaw cycle. Because of these compressible inserts  28 , the pre-cast blocks can float on the center post  12  thereby avoiding the accumulation of tensile and compressive forces that can readily fracture hand crafted stone columns or even those with pre-cast blocks that are mortared and locked into fixed positions. For stone columns, such as those shown in  FIG. 1 , that are employed as fence columns, the thermal expansion of the fencing segments can produce significant lateral loads on the stone columns that can be absorbed by the compressible inserts  28  thereby avoiding damage to the stone columns through cracking of the column materials. 
     Those skilled in the art appreciate that variations from the specified embodiments disclosed above are contemplated herein and that the described embodiments are not limiting. The description should not be restricted to the above embodiments, but should be measured by the following claims.