Abstract:
A mortarless concrete block retaining wall is formed from special blocks arranged in set-back tiers and interlocked by a special post groove arrangement. Each block is trapezoidal in plan view with a pair of laterally spaced posts projecting from the top surface of the block. A groove on the bottom surface of the block fits over adjacent posts in the underlying tiers. The vertically adjacent tiers are laterally offset to interlock the tiers via the post/groove arrangement. The post/groove arrangement allows for blocks that are adjustable to interlock the tiers in a straight configuration or in varying degrees of convex and concave curved configurations.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application is based on and claims the benefit of provisional application Serial No. 60/448,028 filed Feb. 17, 2003. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention relates generally to masonry blocks which may be used in the construction of landscaping elements. More specifically, the invention relates to mortarless retaining wall blocks.  
         BACKGROUND OF THE INVENTION  
         [0003]    Protection of natural and artificial structures, soil retention and increased land use are only a few reasons which motivate the use of landscape structures. When reliance on natural feature is not possible or practical, man often resorts to the use of artificial mechanisms such as retaining walls.  
           [0004]    Many different materials may be used to construct retaining walls depending upon the given application. One common solution is the use of mortarless concrete blocks. Blocks used for these purposes include those disclosed by Hodel U.S. Pat. No. 5,161,918, Woolford U.S. Pat. No. 6,142,713, Risi et al, U.S. Pat. No. 4,490,075 and U.S. Des. Pat. No. 280,024 and Forsberg, U.S. Pat. No. 4,802,320 and U.S. Des. Pat. No. 296,007 among others. These blocks have typically been patterned and weighted so that they may be used to construct a wall which will stabilize the landscape by the shear weight of the blocks.  
           [0005]    Mortarless concrete block retaining walls generally have the advantages that they are inexpensive, easy to construct with unskilled labor, have long life, and will adapt to ground subsidence which could crack a poured concrete or mortared wall. Conventional mortarless retaining walls used to hold earth embankments are typically made of poured concrete blocks, stone, concrete, and railroad ties.  
           [0006]    To provide adequate strength, stability and long life, a retaining wall preferably is tilted somewhat into the embankment. These systems are often designed to “setback” at an angle to counter the pressure of the soil behind the wall. Setback is generally considered the distance which one course of a wall extends beyond the front of the next highest course of the same wall. Given blocks of the same proportion, setback may also be regarded as the distance which the back surface of a higher course of blocks extends backwards in relation to the back surface of the lower wall courses. In vertical structures such as retaining walls, stability is dependent upon the setback between courses and the weight of the blocks. It is an ideal to have a wall that has sufficient setback to allow for adequate pressure on the backfill and structural integrity of the retaining wall, while at the same time minimizing the setback for aesthetic and space considerations.  
           [0007]    Despite the popularity of mortarless systems, many of the mortarless methods are outdated and complex involving the use of separate metal clips, or pins to secure the courses to one another. This is costly and making curved walls with these blocks and clips is difficult and requires considerable skill. For example, to make a wall with an outside curvature (that is, outwardly convex) certain ears that are required for a straight wall must be carefully and precisely knocked off.  
           [0008]    Several attempts have been made to provide a mortarless retaining wall block that maximizes the advantages discussed above while allowing for the construction of curved walls. For example, U.S. Pat. No. 5,294,216 to Sievert discloses a masonry block comprising a block body having an irregular trapezoidal shape and comprising a front surface and a back surface, an upper surface and a lower surface, and first and second sidewalls. The block however, further includes a flange extending downward from the rear surface of the block in order to form a locking surface and further requires the use of an anchoring matrix. The flange limits the amount of curvature allowed in the wall and is prone to cracking and chipping. U.S. Pat. No. 6,142,216 to Woolford et al. discloses a similar retaining wall block to that disclosed in Sievert having a generally planar upper surface, a generally planar lower surface and a flange extending off the lower surface.  
           [0009]    The current designs of pinless, mortarless masonry blocks generally fail to resolve problems such as the ability to construct walls which follow the natural contour of the landscape in a radial or serpentine pattern. Previous blocks also have failed to provide a system to stabilize the stacked course without complex pinning or strapping fixtures. Reliance on such complex fixtures often discourages the use of retaining wall systems by the every day homeowner. Commercial landscapers generally avoid complex retaining wall systems as the time and expense involved in constructing these systems is not supportable given the price at which landscaping services are sold.  
           [0010]    As can be seen, the present state of the art of forming masonry blocks as well as the design and use of these blocks to build structure has definite shortcomings.  
         SUMMARY OF THE INVENTION  
         [0011]    In view of the foregoing, it is a primary object of the invention to provide a mortarless retaining wall which is inexpensive, easy to construct with unskilled labor, having adjacent tiers permanently interlocked in a predetermined set-back relationship, in a straight configuration, or in a wide range of optional convex and concave curved configurations. The present inventive locking function provided by the inventive post and groove combination is highly advantageous to those systems disclosed in the Sievert, Woolford, and other patents.  
           [0012]    In particular, the object of this invention is to provide a special concrete block with integral stubs or posts and grooves for interlocking a plurality of such blocks when arranged side by side in successive set-back tiers to thereby provide an improved, mortarless retaining wall.  
           [0013]    Consistent with the foregoing objects and in accordance with the present invention, there is provided a composite masonry block comprising a block body having a front surface and a substantially parallel back surface, an upper surface and a lower surface, two intermediary walls, and two sidewalls. The intermediary walls extend from the block front surface towards the block back surface at an angle less than ninety degrees in relationship to the block front surface. The sidewall adjoins the intermediary wall and lies between the intermediary wall and the block back surface. The block of the present invention also comprises two posts or stubs projecting upwardly from the upper surface and a groove that extends side-to-side in the bottom surface of the block. The posts are fitted to be inserted inside the groove when the blocks are stacked upon one another in successive courses.  
           [0014]    In accordance with a further aspect of the present invention there are provided landscaping structures such as retaining walls comprising a plurality of courses, each of the courses comprising a plurality of the composite masonry blocks of the present invention.  
           [0015]    These, and other, aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    A clear conception of the advantages and features constituting the present invention, and of the construction and operation of typical mechanisms provided with the present invention, will become more readily apparent by referring to the exemplary, and therefore non-limiting, embodiments illustrated in the drawings accompanying and forming a part of this specification, wherein like reference numerals designate the same elements in the several views, and in which:  
         [0017]    [0017]FIG. 1 is a front perspective view of a preferred embodiment of the retaining wall block in accordance with the present invention;  
         [0018]    [0018]FIG. 2 is a top plan view of the retaining wall block shown in FIG. 1;  
         [0019]    [0019]FIG. 3 is a bottom plan view of the retaining wall block shown in FIG. 1;  
         [0020]    [0020]FIG. 4 is a left side elevational view of the retaining wall block shown in FIG. 1;  
         [0021]    [0021]FIG. 5 is a rear elevational view of the retaining wall block shown in FIG. 1;  
         [0022]    [0022]FIG. 6 is a front elevational view of the retaining wall block shown in FIG. 1;  
         [0023]    [0023]FIG. 7 is a partially cut away perspective view of a retaining wall constructed with the preferred embodiment of the retaining wall block of the present invention;  
         [0024]    [0024]FIG. 8 is a cut away view of the wall shown in FIG. 7;  
         [0025]    [0025]FIG. 9 is a partially cut away perspective view of a retaining wall having a serpentine pattern constructed with the preferred embodiment of the retaining wall block of the present invention;  
         [0026]    [0026]FIG. 10 is a partially cut away perspective view of a retaining wall having a serpentine pattern constructed with the preferred embodiment of the retaining wall block of the present invention;  
         [0027]    [0027]FIG. 11 is a fragmentary top view of the wall shown in FIG. 7;  
         [0028]    [0028]FIG. 12 is a fragmentary top view of the wall shown in FIG. 9; and  
         [0029]    [0029]FIG. 13 is a fragmentary top view of the wall shown in FIG. 10. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0030]    In describing the preferred embodiments of the invention which are illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For example, the word “connected” or terms similar thereto are often used. Such terms are not limited to direct connection but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art. Furthermore, certain dimensions of the block are given to help illustrate the preferred embodiment, however, the inventive concept could be applied to numerous varying dimensions and the inventive concept includes such variations.  
         [0031]    Accordingly, the present invention provides a retaining wall block, and structures resulting from this block. The present invention provides a mortarless interlocking masonry block which may be used to construct any number of structures having a variety of patterns.  
         [0032]    Retaining Wall Block  
         [0033]    Referring to the drawings wherein like numerals represent like parts throughout several views, a retaining wall block  1  is generally shown in FIGS.  1 - 6 . The first aspect of the present invention is a retaining wall block having an irregular hexagonal shaped block body  2 .  
         [0034]    Block  1  is a unitary member preferably of high density concrete. The block body  2  generally comprises a front surface  3  and a back surface  5  which are substantially parallel to each other. In the preferred embodiment, the front surface is about  8  and two thirds inches long and the back surface is about  9  inches long. The front  3  and back  5  surfaces are separated by a distance comprising the depth of the block. In the preferred embodiment, the depth of the block  1  is about eight inches, however the design and inventive concept is applicable to an infinite number of dimensions. The block  1  also has a generally smooth upper  7  and lower surface  9  separated by a distance comprising the height of the block  1 . In the preferred embodiment, the height of the block  1  is about four inches.  
         [0035]    The block  1  further has first  15   a  and second  15   b  intermediary walls adjacent to the side edges of the front surface  3 . In the preferred embodiment, the intermediary walls are about 2.2 inches long. As shown in FIG. 2, the intermediary walls  15   a,    15   b  extend from the block front surface  3  towards the back surface  5  at an angle, alpha, which is less than ninety degrees in relationship to the block front surface  3 . In the preferred embodiment, alpha is about 40 degrees. The block also has first  11   a  and second  11   b  sidewalls separated by a distance comprising the width of the block. In the preferred embodiment, the width of the block measured from the juncture points  27   a,    27   b  is about twelve inches although numerous dimensions are envisioned. The sidewalls  11   a,    11   b  adjoin the block upper  7  and lower  9  surfaces. The sidewalls  11   a,    11   b  further adjoin and lie between the intermediary walls  15   a,    15   b  and the block back surface  5 . Preferably, the sidewalls  11   a,    11   b  converge towards each other as these surfaces move towards the back surface  5  of the block  1 . As illustrated in FIG. 2, the angle, beta, between the sidewall and the back surface preferably ranges in magnitude from about 30 degrees to about 60 degrees in relation to the block back surface. The block has two juncture points  27   a,    27   b  where the side walls  11   a,    11   b  adjoin the intermediary walls  15   a,    15   b.    
         [0036]    Referring now to FIGS. 3 and 4, the lower surface  9  of the block  1  has a groove  19  of given depth “h” and width “w” that extends from the first side wall  11   a  to the second sidewall  11   b  at a location slightly forward of the longitudinal middle of the block  1 . In the preferred embodiment, the center of the groove is about 3.5 inches from the front surface  3  of the block  1 . Furthermore, in the preferred embodiment h is about 0.5 inches and w is about 2.25 inches however the design and inventive concept is applicable to an infinite number of dimensions. The upper surface  7  of the block  1  further comprises two horizontally aligned circular posts or stubs  21   a,    21   b  projecting upwardly from the upper surface  7  in the longitudinal middle of the block. Preferably, the center of the posts  21   a,    21   b  exists about four inches from the front surface  3  and rear surface  5  of the block  1 . In the preferred embodiment, the centers of the posts  21   a,    21   b  are spaced about five inches apart. The posts  21   a,    21   b  have a given height “h” and width “w.” Preferably h′ is about 0.375 inches and w′ is about 2 inches at its widest point. As illustrated by the preferred embodiment, the posts  21   a,    21   b  have rounded edges  77  at the top, but a squared edge is envisioned as well. The rounded edge  77  allows for ease of manipulation of blocks  1  as they are being aligned in their post/groove arrangement.  
         [0037]    It is not compulsory that the posts  21   a,    21   b  be circular or of the given dimensions, even though this is preferred. However, it is compulsory that the posts  21   a,    21   b  have a height “h” equal to or smaller than the depth “h” of the groove  19 . It is also compulsory that the posts  21   a,    21   b  have a width “w” which is substantially equal to or slightly smaller than the width “w” of the groove  19 . As will be described in further detail below, the groove  19  is designed to fit over the posts  21   a,    21   b  when the blocks are stacked in courses. This interlocking feature of the groove  19  and posts  21   a,    21   b  creates greater stability in the finished retaining wall.  
         [0038]    Generally, the block  1  may vary in shape and dimension in accordance with the present invention. Distinctive of the present invention is the ability to use the block  1  seen in FIGS.  1 - 6  to construct either straight or serpentine mortarless retaining walls. Accordingly, the block  1  of the present invention preferably has an irregular hexagonal shape having parallel front  3  and back surfaces  5 . The necessarily irregular nature of the hexagonal block  1  of the present invention comes from the varying lengths of the block&#39;s intermediary walls  15   a,    15   b,  sidewalls  11   a,    11   b,  front  3  and back  5  surfaces.  
         [0039]    Referring again to FIGS.  1 - 5 , the block body  2  generally has eight surfaces. The front surface  3  generally faces outward from the structure and has a roughened appearance to enhance the blocks aesthetic appeal although a smooth surface or other decorative face is envisioned. The back surface  5  of the block  1  generally lies parallel to the front surface  3  and is generally smooth in appearance. The upper surface  7  generally lies parallel to the bottom surface  9 . Both the upper  7  and lower  9  surfaces are also generally smooth in appearance.  
         [0040]    The block intermediary wall  15   a,    15   b  surfaces have a series of ridges or grooves  18 . This generally ridged appearance also enhances the blocks  1  aesthetic appeal. The ridges are comprised of a series of peaks  78  and valleys  79 . In the preferred embodiment the peaks are spaced about 0.250 inches apart. The block  1  sidewall surfaces  11   a,    11   b  lie across the width of the block. As shown in FIGS. 7, 9, and  10 , the interaction between the sidewalls  11   a,    11   b  and intermediary walls  15   a,    15   b  of the block body  2  of the present invention allow for the construction of straight structures (FIG. 7) or serpentine structures including outside radius turns (FIGS. 9,10).  
         [0041]    The inventive block can be used to construct a straight wall  31 . An aligned straight wall can be constructed by aligning the adjacent juncture points  27   a,    27   b  of the same wall course, (see  27   a,    27   b  FIG. 7). Optionally, the same embodiment of the block of the present invention allows the construction of aligned serpentine structures as seen in FIGS. 9, 10,  12  and  13 . In the serpentine wall, the block sidewalls  11   a,    11   b  align with adjoining sidewalls in the same course, (see  11   a,    11   b  FIG. 10).  
         [0042]    As can be seen in FIG. 8, the blocks of each successive course will setback from blocks from the course below. This is a result of the offset between the posts  21   a,    21   b  and groove  19 . As noted above, the center of the posts  21   a,    21   b  are located about 4 inches from the front surface of the block. Alternatively, the center of the groove  19 , is located 3.5 inches from the front surface of the block. Therefore, each successive course will have a setback of about 0.5 inches. Generally, each successive course of blocks should setback far enough to maintain the stability of the soil  35  behind the wall. This preferred setback range provides minimal setback, (for aesthetic value) while ensuring stability of the soil behind the wall.  
         [0043]    In its most preferred mode, the block  1  of the present invention is suitable for both commercial and residential use by landscapers as well as homeowners for use in building landscape structures  
         [0044]    Block Structures  
         [0045]    The composite masonry block  1  of the present invention may be used to build any number of landscape structures. Examples of the structures which may be constructed with the block of the present invention are seen in FIGS.  7 - 10 . As can be seen in FIG. 7, the composite masonry block  1  of the present invention may be used to build a retaining wall  31  using individual courses  33  to construct to any desired height. The blocks  1  may be stacked in an even pattern or an offset pattern depending on the intended application.  
         [0046]    Generally, construction of a structure such as a retaining wall  31  may be undertaken by first defining a trench (not shown) area beneath the plane of the ground  35  in which to deposit the first course  37  of blocks  1 . The first course  37  of blocks  1  is then laid into the trench. As can be seen in FIGS.  11 - 13 , successive courses  33  of blocks are then stacked on top of preceding courses while backfilling the wall  31  with soil. As best illustrated in FIGS.  11 - 13 , successive courses of blocks  1  are stacked in a manner such that the groove  19  fits over the posts  21   a,    21   b  of the underlying blocks  1 . This arrangement is repeated throughout the courses until a desired height is reached. As stability is dependent upon weight and minimal setback, the minimal setback provided by the blocks  1  of the present invention assists in further stabilizing even lighter weight blocks. This minimal setback adds to the stability of smaller size blocks by slowing the horizontal movement backward of the wall through the addition of successive courses. In the preferred embodiment, the blocks weigh about twenty-five pounds. Due to this weight, the block structures are most stable at a height of up to about thirty six inches. However, by increasing the weight of the blocks stable walls can be constructed over thirty-six inches, and such blocks and structures are envisioned as part of the present invention. Clearly, the inventive concept could be applied to numerous varying weights and dimensions and the inventive concept includes such variations.  
         [0047]    Still referring to FIGS.  11 - 13 , fragmentary top views of two courses of a wall are shown. FIG. 11 illustrates the post/groove arrangement of two courses in a straight wall. As illustrated, the stacked courses are typically laterally offset such that the groove of one block  1  in an upper course fits over one post  21   a  of one block in a lower course, and another post of an adjacent block  21   b  in the lower course. FIGS. 12 and 13 illustrate the post/groove arrangement of two courses in a curved and serpentine wall. These illustrations demonstrate a key advantage of the post/groove arrangement of the present invention. Because the groove  19  is continuous with the width of the block, several different angles between adjacent blocks and courses can be accommodated while maintaining the post/groove interlocking arrangement of successive courses. Furthermore this can be accomplished without the use of pins or straps.  
         [0048]    Another benefit of the blocks  1  of the present invention is the combination intermediary wall  15   a,    15   b  and sidewall  11   a,    11   b.  While the intermediary walls  11   a,    11   b  have an angle of less than 90 degrees in relationship to the front surface of the block  3 , the block sidewalls  11   a,    11   b  converge or angle towards each other as the sidewall moves towards the back surface  5  of the block. The converging block sidewalls  11   a,    11   b  allow the blocks  1  to be set in a range of angles relative to adjacent blocks of the same course, FIG. 9.  
         [0049]    When a straight wall is desired, FIG. 7, the blocks  1  of the present invention allow for the placement of the blocks flush against each others juncture points  27   a,    27   b.  As can be seen in FIG. 7, block juncture points  27   a  and  27   b  of two adjacent blocks are flush against one another while the adjacent sidewalls  11   a,    11   b  are spaced apart. In contrast, if a more highly angled serpentine wall is desired, the blocks  1  of the present invention allow for the placement of the blocks with the sidewalls  11   a,    11   b  flush against each other. (FIG. 10). In both instances, there is the desired tight block placement.  
         [0050]    The above discussion, examples, and embodiments illustrate the current understanding of the invention. Certain dimensions of the block were given to help illustrate the preferred embodiment, however, the inventive concept could be applied to numerous varying dimensions and the inventive concept includes such variations. Since many variations of the invention can be made without departing from the spirit and scope of the invention, the invention resides wholly in the claims hereafter appended.