Abstract:
A method for creating a split face on a block, such as a retaining wall block, that includes curved features. The method includes using at least one curved blade to impart a splitting force on an unfinished block. The curve of the blade is imparted through the block as the block splits. The result is an irregular, broken split face having a curved feature.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The method and device of the present invention relate to the production of retaining wall blocks having decorative front features.  
         [0002]     Over the past several years, the popularity of aggregate blocks for use in building retaining walls has increased dramatically. This increase in popularity has predictably been accompanied by an increase in the number of block types available for purchase by landscapers and homeowners alike.  
         [0003]     Most of the blocks on the market are of similar composition and quality. For the average buyer, selecting one block over another usually becomes a matter of aesthetics. The most popular blocks include a broken front face. Broken front faces are created by molding a double block—a block that, when split, will become two finished blocks. The double blocks lack front faces. The front faces of the two finished blocks are created by splitting the double block down the center. Splitting the block involves placing the blocks between two opposing blades along a split line. The blades are moved slightly toward each other, causing the block to break in half. The result is a broken front face that is very irregular and unique. A wall made up of blocks having broken front faces is attractive because it is more complex and less patterned than walls created from blocks having molded front faces.  
         [0004]     The popularity of the broken front face led to the creation of a block with three broken front faces. These blocks have a center front face that is relatively normal to the depth of the block, and two side front faces that angle rearwardly, and may be created by making two subsequent splits after the double block is split into two blocks. Time saving measures have included using blades having multiple straight portions to create angled cuts in a single step. These angled cuts have heretofore always involved angles that splay away from the centerline. Angling toward the centerline, in order to produce a somewhat scalloped, or concave effect in the front face of a wall block have not been successful due, in part, to the binding effect on the blade of the material being cut away. Curved cuts have also not been attempted.  
         [0005]     The three faced design is easily the most popular block design being sold today, and has resulted in significant litigation among competitors. Inevitably, a design loses distinction as its popularity grows, which eventually results in waning sales. However, broken faces are objectively more attractive than smooth faces due to the rustic look and interesting shadows cast by the irregularities in the broken faces. Unfortunately, the present splitting techniques are limited in their ability to create different effects. Additionally, creativity with the present splitting techniques usually comes at the cost of significant wasted block material.  
         [0006]     There is a need for an alternative splitting technique that allows unique curved patterns to be made in the front face of a retaining wall block.  
         [0007]     There is also a need for an alternative splitting technique that can create unique patterns in the front face of a retaining wall block with a single split.  
         [0008]     There is a further need for an alternative splitting technique and device that allows concave features to be formed in the front face of a retaining wall block.  
       BRIEF SUMMARY OF THE INVENTION  
       [0009]     The present invention relates to a splitting blade and a method that allows a retaining wall block to be split along curved lines. By providing a curved splitting blade, or two opposing curved splitting blades, the curve of the splitting blade is surprisingly transferred through the block as it is split into two finished blocks.  
         [0010]     One aspect of the present invention is a blade for use in splitting blocks comprising a body and at least one curved portion operably attached to the body, the at least one curved portion having a curved cutting edge. The blade may further comprise at least one straight portion operably attached to the body, the at least one straight portion having a straight cutting edge.  
         [0011]     Another aspect of the present invention is a method of creating a split curved feature on a composite block comprising providing a splitting device having at least one blade with at least one curved portion, placing a block in operable proximity to the at least one curved portion of the at least one blade, and exerting a force on the block with the at least one curved portion of the blade sufficient to split the block. The splitting device may have two opposing blades, one or each of which having at least one curved portion. The block may then be placed between the two opposing blades and the blades moved toward each other until the block splits. An interesting “tumbled” effect may be obtained by using opposed blades, each having curved features that do not align with each other.  
         [0012]     Another aspect of the invention provides a blade for use in splitting blocks comprising a means for creating a curved split feature in a face of the block. The means may comprise a blade having at least one curved portion. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is perspective view of an example of a double block that has not yet been split;  
         [0014]      FIG. 2   a  is perspective view of an embodiment of a curved cutting blade of the present invention;  
         [0015]      FIG. 2   b  is a perspective view of a retaining wall block split with the blade of  FIG. 2   a;    
         [0016]      FIG. 3   a  is a perspective view of a second embodiment of a curved cutting blade of the present invention;  
         [0017]      FIG. 3   b  is a perspective view of a retaining wall block split with the blade of  FIG. 3   a;    
         [0018]      FIG. 3   c  is a perspective view of a portion of a wall constructed with blocks similar to the block of  FIG. 3   b;  and,  
         [0019]      FIG. 4  is a plan view of a course of retaining wall blocks having been split using the method of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]     Referring now to the Figures, and first to  FIG. 1 , there is shown an example of a double-block  1  on which the method and device of the present invention may be used. The double-block  1  has been cast into the shape shown and needs only to be split into two blocks to be completed. Notably, the surfaces  2  are all smooth, as a result of the casting process. The block is ready to be split along a split line  3  (illuminated by a dashed line). Typically, a large, somewhat blunt blade is used, often in conjunction with a similar opposing blade, to break the double-block  1  into two finished blocks. The double block  1  is compressed between the two blades along the split line  3  and breaks into two finished blocks each having a relatively straight yet irregular, broken front face. If it is desired to create a block having more facets, further breaks are made. A three-faced front surface is made by breaking the split blocks along lines  4 ,  5 ,  6  and  7 . The shaded areas  8  are wasted material.  
         [0021]     The present invention provides a method of creating curved, yet broken front faces using curved blades.  FIG. 2   a  shows a blade  20  having curved portions  22  on either side of a straight portion  24 . The curved portions  22  each have a curved tapered portions  26  that lead to a curved cutting edge  28 . The cutting edge is dull when compared to conventional cutting blades of other types, such as knives, saw blades, and the like. Because the blade is just starting a crack in the block, rather than cutting through the entire block, and because it is used to cut aggregate rock materials, a dull cutting edge is stronger and lasts much longer than would a sharpened cutting edge.  
         [0022]     Similarly, the straight portion  24  has a tapered portion  30  that leads to a straight cutting edge  32 . The straight portion also has a body  34  that includes two attachment holes  36 , useable to fasten the blade to a splitting device (not shown). The curved portions  22  may be attached to the blade at any desired location to create a desired effect. Further, the curved portions  22  may be attached by any acceptable means that will allow the curved portions to withstand the pressures of a splitting operation. Examples of acceptable attachment means include but are not limited to: welding, bolting, and forming the curved portions integrally with the rest of the blade, such as by casting, forging, or bending.  
         [0023]     The method of the present invention includes splitting a block using a curved blade to create a split face with a curved portion. The first step is to place a block between a blade having a curved portion and an opposing surface. The opposing surface may be a similarly shaped blade, a straight blade, or even an edge. Alternatively the blade may not be aligned with an opposing surface, rather a space or giving surface may oppose the blade with the double-block being supported by firm surfaces outwardly displaced from a position directly opposing the blade. Another alternative would be to support the entire block on a slightly forgiving surface, such as rubber. Yet another alternative is to provide two opposed blades, each having curved portions that do not align with each other in order to create a “tumbled” effect on the front face of the block. The blade or blades are then forced toward the block until the block splits, thereby creating a split face with a curved portion.  
         [0024]      FIG. 2   b  is a finished block  40  that has been split using the blade  20  of  FIG. 2   a.  The block  40  has a split face  42  that includes a flat portion  44  and two curved portions  46 . The split face  42 , with its curved portions  46 , is somewhat complimentary to the shape of the blade  20 . Due to the inherent variances between blocks, no two blocks  40  split using the blade  20  will have identical faces  42 . If a double-block is used, such as that shown in  FIG. 1 , two such blocks  40  will result. One skilled in the art will realize that the rearward portion  48  of the block  40  is provided by way of example and that the method and device of the present invention can be used with any block design that incorporates a split face.  
         [0025]     Similarly, the present invention should be read as applying to all forms of curved blades.  FIG. 3   a  provides another example of a curved blade design useable to accomplish the present invention. The blade  50  includes a body  52  and a curved cutting portion  54  attached to a distal edge  55  of the body  52 . The body  52  has attachment points  56 , shown as holes, for attaching the body  52  to a splitting device (not shown).  
         [0026]     The curved cutting portion  54  has a tapered portion  58  and a dull cutting edge  60 . The curved cutting portion  53  has been formed into a sine wave, and the blade  50  has no straight portion. The result is a block  62  ( FIG. 3   b ) having a completely curved front broken face  64 . A significant advantage to a block design, such as that shown in  FIG. 3 , is that two complementary, or substantially similar, blocks can be produced by splitting a double-block with no wasted material. Additionally, when the blocks  62  are arranged in a wall, the design complements the design of adjacent blocks, forming a wave like appearance such as that shown in the portion of a wall  66  in  FIG. 3   c.    
         [0027]     A similar result could be achieved by providing a blade with a curved portion that is a semicircle or a one half of a sine wave. Referring to  FIG. 4 , it can be seen that splitting a double-block with such a blade would result in two different blocks  68  and  70  having complementary shapes. Each split would result in one block  68  having a concave split face  72  and another block  70  having a convex split face  74 . When arranged in a wall, the faces  72  and  74  combine to form a sine wave having a wavelength equal to the widths of two blocks. Again, no material is wasted with this design.  
         [0028]     The invention has herein been described in its preferred embodiments to provide those skilled in the art with the information needed to apply the novel principles and to construct and use the embodiments of the examples as required. However, it is to be understood that the invention can be carried out by specifically different devices and that various modifications can be accomplished without departing from the scope of the invention itself, which is set out in the following claims: