Abstract:
A concrete block comprising a front face having a height H 1  and a width L 1.  A lip disposed underneath the front have having a height H 2.  A rear face having a height H 3  and a width L 2,  wherein the rear face is shorter than the sum of H 1  plus H 2  by an amount H 4,  and wherein the sum of H 1  plus H 2  equals the sum of H 3  plus H 4.  An upper surface forming a channel.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention pertains to the field of construction materials, and more specifically to a retaining wall block. 
       BACKGROUND OF THE INVENTION 
       [0002]    Retaining wall blocks and methods of manufacturing retaining wall blocks are known in the art. Prior art retaining wall blocks are generally heavy, because of their intended application, and are therefore expensive to manufacture. 
       SUMMARY OF THE INVENTION 
       [0003]    In accordance with the present invention, a retaining wall block and method of manufacture are provided that result in a retaining wall block that is both lighter and less expensive. 
         [0004]    In accordance with an exemplary embodiment of the present invention, a concrete block is provided. The concrete block includes a front face having a height H 1  and a width L 1 . A lip is disposed underneath the front, and the lip has a height H 3 . A rear face of the concrete block has a height H 2  and a width L 2 , wherein the rear face is shorter than the sum of H 1  plus H 3  by an amount H 4 , and wherein the sum of H 1  plus H 3  equals the sum of H 2  plus H 4 . An upper surface of the concrete block forms a channel, such as a U-shaped channel. 
         [0005]    Those skilled in the art will further appreciate the advantages and superior features of the invention together with other important aspects thereof on reading the detailed description that follows in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a diagram of a retaining wall block in accordance with an exemplary embodiment of the present disclosure; 
           [0007]      FIG. 2  is a rear view of a retaining wall block in accordance with an exemplary embodiment of the present disclosure; 
           [0008]      FIG. 3  is a bottom view of a retaining wall block in accordance with an exemplary embodiment of the present disclosure; 
           [0009]      FIG. 4  is a side view of a retaining wall block in accordance with an exemplary embodiment of the present disclosure; 
           [0010]      FIG. 5  is a rear view of a retaining wall formed from a plurality of retaining wall blocks in accordance with an exemplary embodiment of the present disclosure; 
           [0011]      FIG. 6  is a front view of a straight retaining wall formed from a plurality of retaining wall blocks in accordance with an exemplary embodiment of the present disclosure; 
           [0012]      FIG. 7  is a front view of a curved retaining wall formed from a plurality of retaining wall blocks in accordance with an exemplary embodiment of the present disclosure; 
           [0013]      FIG. 8  is a diagram of a mold for forming a plurality of retaining wall blocks in accordance with an exemplary embodiment of the present disclosure; 
           [0014]      FIGS. 9A through 9D  are diagrams of exemplary cross sectional views of retaining wall blocks in retaining walls in accordance with an exemplary embodiment of the present disclosure; 
           [0015]      FIG. 10  is a diagram showing cross-sectional views of retaining wall blocks in accordance with an exemplary embodiment of the present invention; 
           [0016]      FIG. 11  is a diagram showing retaining wall blocks nested for shipment; 
           [0017]      FIG. 12  is a diagram showing a side view of retaining wall blocks nested for shipment; and 
           [0018]      FIG. 13  is a diagram showing an overhead view of retaining wall blocks nested for shipment. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0019]    In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals. The drawing figures might not be to scale and certain components can be shown in generalized or schematic form and identified by commercial designations in the interest of clarity and conciseness. 
         [0020]      FIG. 1  is a diagram of a retaining wall block  100  in accordance with an exemplary embodiment of the present disclosure. Retaining wall block  100  is a lightweight and low cost retaining wall block, and can be fabricated from concrete or other suitable masonry materials. 
         [0021]    Retaining wall block  100  includes front face  102 , bottom face  104  and rear face  106 . The upper surface  108  of retaining wall block  100  forms a channel that extends through one or more sidewalls and does not form a face, which allows fill material, such as rocks, gravel, or excavated dirt or soil, to be placed within the channel. The channel runs approximately parallel to the front and rear faces, and forms a cross section of the block from the front face to the back face that is approximately constant, as a function of normal manufacturing variations. In this manner, retaining wall block  100  is substantially prismatic along an axis extending approximately parallel to the channel. In this manner, the fill material provides additional mass to a retaining wall formed using plurality of retaining wall blocks  100 , which adds stability to the retaining wall that would otherwise be provided by the additional mass of the retaining wall blocks. In addition, the use of fill material to increase the mass of retaining wall block  100  allows retaining wall block  100  to be manufactured at a lower cost from less raw materials while providing the same amount of mass when installed for use in retaining soil, dirt, rocks or other landscaping materials. Each retaining wall block  100  also costs less to ship on a per-unit basis than other retaining wall blocks, because it weighs less than other solid retaining wall blocks. Retaining wall block  100  also provides benefits over hollow retaining wall blocks, which provide the benefit of having a lower per-unit cost to manufacture and a lower shipping weight, but which are not capable of being filled with material during installation and which therefore do not provide a retaining wall with equivalent mass. 
         [0022]    Retaining wall block  100  also includes lip  110  and shelf  112 , which are configured to interlock with front top surface  116 . The dimensions of lip  110  and shelf  112  can be varied as suitable, but in general, the depth of shelf  112  will usually be less than the thickness of the front section of retaining wall block  100 , to prevent a retaining wall constructed from a plurality of blocks  100  from leaning forward when it is installed. 
         [0023]    Front top surface  116  is shaped so as to fit with the contour of lip  110  of a mating retaining wall block  100 , but can have other suitable forms that are easy to manufacture. Lip  110  may include a plurality of angled portions, so as to allow a mating retaining wall block to be placed in a number of different orientations, based on the design of a retaining wall. Likewise, lip  110  can be made straight and without the angled portions where desired. Retaining wall block  100  also includes rear top surface  118 , rear bottom corner  114  and sidewalls  120  and  122 . 
         [0024]    Front face  102  of retaining wall block  100  can also or alternatively be textured. Texture can be applied by using a liner in the section of the mold corresponding to front face  102 , where the liner can be attached using multiple links or hinges that allow the liner to rest securely against the sidewall of the mold during molding but to swing downward when the mold is raised, so as to disengage from the side of the retaining wall block. 
         [0025]    In use, retaining wall block  100  can be used to build retaining walls that follow existing natural contours. Retaining wall block  100  can be filled with fill material, such as rock, gravel, material from the terrain where the retaining wall is being installed, or other suitable materials that allow retaining wall block  100  to be constructed at a lower cost from less material without a corresponding loss of mass, which is generally required to allow the retaining wall to withstand back pressure from the retained landscaping materials or soil without movement. In addition, the use of local terrain to fill retaining wall block  100  reduces the cost associated with installation, as there will be less displaced earth to be removed. Retaining wall block  100  can also be used with anchors, as further described herein, such as for applications where the back pressure from the retained landscaping materials or material may be high enough to cause the retaining wall to be unstable. 
         [0026]      FIG. 2  is a rear view  200  of retaining wall block  100  in accordance with an exemplary embodiment of the present disclosure. Rear view  200  shows the rear face  106 , bottom face  104 , rear bottom corner  114 , shelf  112 , part of upper surface  108  and sidewall  120  of retaining wall block  100 . The locations of front face  102 , rear top surface  118 , front top surface  116  and sidewall  122  are also indicated, but they are not shown. 
         [0027]      FIG. 3  is a bottom view  300  of retaining wall block  100  in accordance with an exemplary embodiment of the present disclosure. Bottom view  300  shows a width of length L 1  of front face  102  and a width of length L 2  of rear face  106 . Sidewall  120  can be perpendicular to front face  102  and rear face  106 , or can be disposed at a suitable angle. Likewise, sidewall  122  can be disposed at an angle to front face  102  and rear face  106 , or can be perpendicular when coordinated with an angular disposition for sidewall  120 . 
         [0028]    When an angular disposition is provided for one or both of sidewalls  120  and  122  such that L 2  is less than L 1 , retaining wall block  100  can be installed so as to follow a curved landscape feature. In addition, anchors can be used in conjunction with retaining wall block  100  when L 2  is less than L 1 , such as by disposing the anchors between the gaps in adjacent blocks. Because retaining wall block  100  is formed on its side, the width of the front and rear faces will need to be controlled using a stripper shoe that is disposed at an angle during the molding process, as described herein. 
         [0029]      FIG. 4  is a side view  400  of retaining wall block  100  in accordance with an exemplary embodiment of the present disclosure. Side view  400  shows height H 1  of front face  102  and height H 2  of rear face  106 , as well as heights H 3  and H 4 , which represent the differences between the bottom of front face  102  and the bottom surface  104  of retaining wall block  100 , and the top of rear face  106  and the top of front face  102 , respectively. While each height of height pairs (H 1 , H 2 ) and (H 3 , H 4 ) can be equal or different, the sum of H 1 +H 3  should equal the sum of H 2 +H 4 , in order to allow a retaining wall to be formed by stacking a plurality of courses of retaining wall blocks  100 . 
         [0030]    In addition, side view  400  also shows the channel formed by upper surface  108 , which can be filled with rock, gravel, excavated materials or other suitable materials to provide additional mass for a retaining wall, and which also allows the amount of excavated material that must be disposed of to be reduced. Anchor structures such as cross-connected rebar or other suitable materials can be disposed in the channel, or geogrid or fabric materials can be lined along upper surface  108  and trailed behind rear face  106 , prior to filling the channel with fill material. 
         [0031]      FIG. 5  is a rear view  500  of a retaining wall formed from a plurality of retaining wall blocks  100  in accordance with an exemplary embodiment of the present disclosure. While the front faces  102  of the retaining wall blocks  100  form a continuous surface, the rear faces  106  form a plurality of gaps  502 , which allow anchors to be placed within the cavities formed by upper surfaces  108  and to extend through gaps  502  into the soil behind the retaining wall. Fill material can then be placed within the channel and over the anchor. In this manner, no special assembly procedures are required to use anchors with the retaining wall blocks  100 , such as the use of special blocks, block caps or equipment. 
         [0032]      FIG. 6  is a front view  600  of a straight retaining wall formed from a plurality of retaining wall blocks  100  in accordance with an exemplary embodiment of the present disclosure. view  600  shows how the front faces  102  of the retaining wall blocks  100  form a continuous surface. In addition, several of the gaps  502  formed by the rear faces  106  can be seen. The row of cavities formed by a course of blocks can easily be filled by concrete, rebar or other suitable materials to form a bond beam. 
         [0033]    Front view  600  also includes an anchor support  506 , which is connected to anchors  504  by welding, bolts or in other suitable manners. Anchor support  506  is placed within the cavities formed by upper surfaces  108  of retaining wall blocks  100 , and anchors  504  extend through gaps  502  between the retaining wall blocks  100 . In one exemplary embodiment, anchor support  506  can be placed within the cavities of a first course of retaining wall blocks  100 , and anchors  504  can then be placed in gaps  502  between the retaining wall blocks  100  and attached to anchor support  506  by welding, bolts or in other suitable manners. Fill dirt can then be placed within the cavities, and anchors  504  can be covered with a layer of excavated earth. Anchors  504  and also or alternatively be driven into the earth behind the course of retaining wall blocks  100 . After a first course of retaining wall blocks is constructed, a second course can then be constructed on top of the first course. Successive courses can then be installed in the same manner to form a retaining wall. 
         [0034]      FIG. 7  is a front view  700  of a curved retaining wall formed from a plurality of retaining wall blocks  100  in accordance with an exemplary embodiment of the present disclosure. Front view  700  shows how the front faces  102  of the retaining wall blocks  100  form a continuous surface. In addition, the rear faces  106  also form a continuous surface, in that there are no gaps  502 . Front view  700  thus demonstrates one of the advantages of retaining wall block  100 , in that the existing landscape contours can be followed using a single block design, which eliminates the need for different block designs. 
         [0035]      FIG. 8  is a diagram of a mold  800  for forming a plurality of retaining wall blocks  100  in accordance with an exemplary embodiment of the present disclosure. Mold  800  includes a plurality of pairs of mold cavities  804  and  806  that are set in a mold body  802 . Each of mold cavities  804  and  806  yields a retaining wall block  100  when used as a mold, and includes a negative corresponding surface for each of front face  102 , bottom face  104 , rear face  106 , upper surface  108 , lip  110 , shelf  112 , rear bottom corner  114 , front top surface  116  and rear top surface  118 . Sidewalls  120  and  122  are formed by placing mold  800  against a bottom planar surface and by the use of an angled stripper shoe at the top of the mold, respectively. 
         [0036]    Mold  800  is configured for use in a dry cast molding process. Dry cast material is placed within mold cavities  804  and  806 . The dry cast material is pressed, under vibration, into place by a stripper shoe compression head (not explicitly shown), which is inserted into mold cavities  804  and  806 . The stripper shoe compression head can be angled to provide a difference between L 1  and L 2  as shown in  FIG. 3 , if such a difference is desired. Mold  800  is then removed while the stripper shoe compression head is held in place, and the individual nested retaining wall blocks  100  are allowed to harden. A plate can be used to seal the open bottom of the mold during this process. 
         [0037]    In operation, mold  800  increases the efficiency of the manufacturing process for retaining wall blocks by increasing the number of blocks that can be made in a unit space. Unlike prior art blocks that are not capable of being nested, retaining wall blocks  100  can be nested in mold  800 , which results in greater efficiency during the molding process. 
         [0038]      FIGS. 9A through 9D  are diagrams  902 ,  904 ,  906  and  908  of exemplary cross sectional views of retaining wall blocks in retaining walls in accordance with an exemplary embodiment of the present disclosure. Cross sectional view  902  is a stylized version of retaining wall block  100 . Cross sectional view  904  has a front face and a rear face that are of equal height, and includes a lip  910  that abuts the inner surface opposite the front face. Cross sectional views  906  and  908  are essentially the same as cross sectional views  902  and  904 , except they are rotated 180 degrees. 
         [0039]      FIG. 10  is a diagram  1000  showing cross-sectional views of retaining wall blocks in accordance with an exemplary embodiment of the present invention. Retaining wall blocks  1002  and  1004  are shown stacked as they might normally be used, and include rear face  1006 , top beveled edge  1008 , top rear surface  1010 , inside rear surface  1012 , inside bottom surface  1014 , inside front surface  1016 , inside front corner  1018 , inside rear corner  1020 , bottom beveled edge  1022 , notch  1024 , front face  1026 , front top surface  1028  and base  1030 . As shown in diagram  1000 , notch  1024  mates with front top surface  1028 , and base  1030  rests on top rear surface  1010 . Top beveled edge  1008  is provided to allow retaining wall block  1002  to be nested with retaining wall block  1004 , as discussed below. In this regard, top beveled edge  1008  is configured not to impact with inside front corner  1018 . In addition, to allow retaining wall block  1004  to be stacked on top of retaining wall block  1002 , dimension D 1  (which represents the distance between inside rear surface  1012  and inside front surface  1016 ) should be less than dimension D 2  (which represents the depth of base  1030 . The exact dimensions and configuration of top beveled edge  1008 , top rear surface  1010 , inside front corner  1018 , inside rear corner  1020 , bottom beveled edge  1022 , notch  1024  and base  1030  can be varied to accommodate manufacturing tolerances. 
         [0040]    Wall thickness T of retaining wall blocks  1002  and  1004  does not need to be uniform as long as other critical dimensions are maintained, but is generally determined based on the material characteristics of the concrete or other masonry materials that is being used to manufacture the retaining wall blocks. Because retaining wall blocks  1002  and  1004  are used to minimize the amount of concrete or other masonry material that is needed to manufacture the retaining wall blocks, in order to reduce the per-block cost of each retaining wall block and associated shipping weight, the wall thickness will typically be uniform. 
         [0041]    Because retaining wall blocks  1002  and  1004  have an opening in the top and inner channel, a cap can also be used to provide an aesthetically-pleasing top surface to a completed retaining wall. In order to provide a “capless” retaining wall block, such that an additional cap block does not need to be manufactured or kept in stock, the rear face can be broken off at break point X to allow fill material to be uniformly provided up to the rear surface of the front wall. In addition, a notch or other feature can be provided at break point X to make it easier to break off the rear face, although such features might also result in greater inadvertent breakage. Based on the material strength of concrete and other masonry materials, another block or other common construction equipment such as a hammer should be sufficient to allow the rear face to be easily broken off by construction personnel without the need for a break point notch. 
         [0042]    A mold liner can be utilized to provide an embossed front face  1026 , where suitable. Such mold liners are typically attached to one side of the mold by hinges or links, and swing away from the molded block when the mold is lifted off the block. 
         [0043]      FIG. 11  is a diagram  1100  showing retaining wall blocks  1002  and  1004  nested for shipment. As shown in diagram  1100 , the rear faces of each of retaining wall blocks  1002  and  1004  are placed with the inner channel of the other block, such that the angled side faces  1102   1104  of retaining wall blocks  1002  and  1004 , respectively, are disposed on one side and the perpendicular side faces of retaining wall blocks  1002  and  1004  are disposed on the opposite side. 
         [0044]      FIG. 12  is a diagram  1200  showing a side view of retaining wall blocks  1002  and  1004  nested for shipment. As shown in diagram  1200 , the rear face of retaining wall block  1002  can abut the inside front surface of retaining wall block  1004 , and the base of retaining wall block  1002  covers the channel of retaining wall block  1004 . The angled side faces  1102  and  1104  of retaining wall blocks  1002  and  1004 , respectively, are disposed on one side and the perpendicular side faces  1202  and  1204  of retaining wall blocks  1002  and  1004 , respectively, are disposed on the opposite side. 
         [0045]      FIG. 13  is a diagram  1300  showing an overhead view of retaining wall blocks  1002  and  1004  nested for shipment. As shown in diagram  1300 , the rear face  1006  of each retaining wall block abuts the inside front surface  1016  of the other retaining wall block, and top beveled edge  1008  of each retaining wall block does not interfere with the inside rear corner  1020  of the other retaining wall block. In this manner, the retaining wall blocks can be securely nested for shipment to reduce the amount of pallet space required. 
         [0046]    Although exemplary embodiments of a system and method of the present invention have been described in detail herein, those skilled in the art will also recognize that various substitutions and modifications can be made to the systems and methods without departing from the scope and spirit of the appended claims.