Patent Publication Number: US-6701687-B1

Title: Modular wall block with mechanical course connector

Description:
TECHNICAL FIELD AND BACKGROUND OF INVENTION 
     This invention relates to a modular wall block including one or more mechanical course connectors, and a retaining wall constructed of an assembly of such blocks in stacked courses. The invention is particularly applicable for landscaping around residential and commercial structures to retain and preserve the surrounding soil while promoting the aesthetics of the area. As a result of its relatively low cost, ease of manufacture, and handling, concrete masonry block has emerged as one of the most popular and widely accepted material for use in constructing retaining walls. Blocks of this type are molded in a form. 
     Conventional retaining walls formed of concrete blocks are constructed in stacked courses with the ascending courses typically setback to counter the pressure of the soil acting against the wall. Mechanical means, such as geogrid mats or tie-backs, are commonly used to help stabilize the soil and further anchor the blocks in the wall. While such means are generally effective, a need exists in the industry for an improved course connector which mechanically interconnects the stacked block courses without interfering with placement or setback requirements, and which promotes stable, efficient, and precise construction of the retaining wall. 
     SUMMARY OF INVENTION 
     Therefore, it is an object of the invention to provide an improved wall block which uses course connectors to readily and conveniently position, align, and secure the blocks in stacked courses of the retaining wall. 
     It is another object of the invention to provide an improved wall block which uses a mechanical course connector to establish the setback of the block relative to an upper or lower course of blocks. 
     It is another object of the invention to provide an improved wall block which uses a mechanical course connector to achieve uniform and consistent setback throughout curves in the retaining wall. 
     It is another object of the invention to provide an improved wall block which is relatively lightweight and easy to handle. 
     It is another object of the invention to provide an improved wall block which is especially applicable for landscaping around plants and shrubs. 
     It is another object of the invention to provide an improved wall block with a rear portion adapted for being conveniently broken off and sides of reduced dimension, such that only a small portion of the block top is visible after backfilling with soil. 
     It is another object of the invention to provide an improved wall block which maximizes the available space surrounding the block for plantings. 
     It is another object of the invention to provide an improved course connector for use in combination with a wall block to position, secure, and align the block in a stacked course of the retaining wall. 
     It is another object of the invention to provide an improved course connector which extends in three mutually perpendicular directions. 
     It is another object of the invention to provide an improved course connector which is integrally molded of a relatively inexpensive material. 
     It is another object of the invention to provide an improved course connector which is formed in a variety of sizes to conveniently and accurately define the setback of the upper course block relative to the lower course blocks. 
     It is another object of the invention to provide an improved course connector which readily penetrates geogrid matting, and serves to further secure the matting between adjacent courses of the retaining wall. 
     It is another object of the invention to provide a retaining wall constructed of a number of like wall blocks. 
     These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a modular wall block adapted for being assembled together with a number of other blocks in stacked courses to form a retaining wall. The wall block has a front and rear, top and bottom, and opposing sides. At least one of the opposing sides defines a generally L-shaped vertical slot. A course connector is received in the vertical slot, and includes first and second ends joined together by a setback spacer. The first end extends in an x-direction and a y-direction, and defines a generally L-shaped structure received in the L-shaped slot of the wall block. When positioned in the wall block, movement of the course connector is restricted in all directions except upwardly towards the top of the block and downwardly towards the bottom. The second end of the course connector extends outwardly in a z-direction beyond one of the top and bottom of the wall block to engage one of the number of other blocks in an upper or lower course. The setback spacer locates the second end of the course connector a spaced distance from the first end to position the wall block in the retaining wall relative to the other blocks in the upper or lower course. 
     The terms “x, y, and z-directions” are used broadly herein to mean directions along respective axes which run parallel to Cartesian x, y, and z-axes, and which do not all pass through a single common point but which are mutually perpendicular in three dimensions. 
     According to another preferred embodiment, the setback spacer extends in a direction generally parallel to a portion of the first end of the course connector. 
     According to another preferred embodiment, the second end of the course connector forms an elongated vertical spike extending in the z-direction generally perpendicular to the setback spacer. 
     According to another preferred embodiment, the vertical spike and setback spacer of the course connector are integrally formed together at a center portion of the vertical spike, such that course connector is applicable for use on either of the opposing sides of the wall block. 
     According to another preferred embodiment, the vertical spike of the course connector defines opposing pointed ends adapted to facilitate penetration of the vertical spike through earthen backfill located behind the retaining wall. 
     According to another preferred embodiment, the course connector is integrally-formed of a molded material. 
     According to another preferred embodiment, the course connector is formed of a glass-filled nylon. 
     According to another preferred embodiment, the top of the wall block defines a lateral tie-back channel extending from one side of the block to the other. The channel is adapted for receiving an elongated tie-back element cooperating to anchor the block to earthen backfill behind the retaining wall. 
     According to another preferred embodiment, an edge defining the lateral channel is beveled to facilitate placement of the tie-back element in the wall block. 
     According to another preferred embodiment, an edge defining the vertical slot is rounded adjacent the top of the wall block for accommodating an anchor strap positioned in the lateral tie-back channel and extending rearwardly into earthen backfill behind the retaining wall. 
     According to another preferred embodiment, the front, rear, and opposing sides define a hollow core of the wall block. 
     According to another preferred embodiment, the sides of the wall block taper inwardly from the front to the rear. 
     According to another preferred embodiment, the opposing sides of the wall block are reduced relative to the front and rear to allow an increased amount of soil behind the front. 
     In another embodiment, the invention is a retaining wall constructed of a number of modular wall blocks assembled in stacked courses. Each of the wall blocks has a front and rear, top and bottom, and opposing sides. At least one of the opposing sides defines a generally L-shaped vertical slot. A course connector is received in the vertical slot, and includes first and second ends joined together by a setback spacer. The first end extends in an x and y-direction, and defines a generally L-shaped structure received in the L-shaped slot. When positioned in the wall block, movement of the course connector is restricted in all directions except upwardly towards the top of the block and downwardly towards the bottom. The second end of the course connector extends outwardly in a z-direction beyond one of the top and bottom of the wall block to engage one of the number of other blocks in an upper or lower course. The setback spacer locates the second end of the course connector a spaced distance from the first end to position the wall block in the retaining wall relative to the other blocks in the upper or lower course. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Some of the objects of the invention have been set forth above. Other objects and advantages of the invention will appear as the description proceeds when taken in conjunction with the-following drawings, in which: 
     FIG. 1 is a front perspective view of a wall block according to one preferred embodiment of the present invention, and showing a course connector located in the vertical slot of the block; 
     FIG. 2 is a rear perspective view of the wall block showing both course connectors located in respective vertical slots; 
     FIG. 3 is a top plan view of the wall block with the course connectors removed; 
     FIG. 4 is a front perspective view of a partially completed retaining wall formed using wall blocks of the present invention; 
     FIG. 5 is a rear perspective view of the retaining wall; 
     FIG. 6 is an enlarged, first perspective view of the course connector; 
     FIG. 7 is an enlarged, second perspective view of the course connector; 
     FIG. 8 is an enlarged, third perspective view of the course connector; 
     FIG. 9 is a rear perspective view of a partially completed retaining wall with geogrid matting arranged for placement between adjacent courses of the wall; 
     FIG. 10 is a front perspective view of a wall block according to a second preferred embodiment of the present invention; and 
     FIG. 11 is a rear perspective view of the wall block shown in FIG.  10 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT AND BEST MODE 
     Referring now specifically to the drawings, a modular wall block according to the present invention is illustrated in FIGS. 1-3, and shown generally at reference numeral  10 . The wall block  10  is adapted for being assembled, as shown in FIGS. 4 and 5, with a number of like blocks in stacked courses “C” to form a retaining wall “W”. The wall blocks  10  are preferably formed of molded masonry concrete. 
     The wall block  10  has a front  11  and rear  12 , top  14  and bottom  15 , and opposing sides  16  and  17 . In one embodiment, the front  11  includes vertical breaks  18  and  19  defining a center face portion  11 A and opposing side face portions  11 B and  11 C. Preferably, the center face portion  11 A has an aesthetic, unfinished, rough textured surface. The core of the wall block  10  is hollow to reduce the overall weight of the block  10 , and for convenient handling and placement of the block  10  during construction of the retaining wall. 
     The sides  16  and  17  define respective vertical, L-shaped slots  21  and  22  extending through the wall block  10  from the top  14  to the bottom  15 . The vertical slots  21 ,  22  are designed to receive mechanical course connectors  25 , described below, which operate to conveniently position, align, and secure the wall blocks  10  in the retaining wall “W”, as shown in FIGS. 4 and 5. Alternatively, the vertical slots  21 ,  22  may extend only partially through the wall block  10 . 
     A single course connector  25  is illustrated in FIGS. 6,  7 , and  8 . The course connector  25  is preferably molded of a glass-filled nylon, and includes first and second ends  26  and  27  integrally joined together by a setback spacer  28 . The first end  26  extends in both an x-direction and y-direction, as indicated at  31  and  32 , respectively, and defines a generally L-shaped structure which is received in the corresponding vertical slot  21 ,  22  of the wall block  10 . When properly positioned in the vertical slot  21 ,  22 , movement of the course connector  25  is restricted in all directions except upwardly towards the top  14  of the block  10  and downwardly towards the bottom  15 . The elongated setback spacer  28  is integrally formed with the first end  26  of the course connector  25 , and extends in a direction perpendicular to the x-direction  31  of the first end  26  and parallel to the y-direction  32  of the first end  26 . 
     The opposite end of the setback spacer  28  is integrally formed with the second end  27  of the course connector  25 . The second end  27  extends perpendicular to the setback spacer  28  in a z-direction indicated at  33 . The second end  27  comprises a vertical spike  35  with opposing pointed ends  36  and  37 . When the blocks  10  are assembled in the retaining wall “W”, as shown in FIGS. 4 and 5, one of the spike ends  36 ,  37  projects outwardly beyond the bottom  15  of the wall block  10  to engage one of the other stacked blocks  10  in a lower course. Preferably, the setback spacer  28  is joined at a center portion of the vertical spike  35  to form opposing identical spike ends, such that the course connector  25  is applicable for use in either the right or left side slot  21 ,  22  of the wall block  10 . The pointed spike ends  36  and  37  facilitate penetration of the course connector  25  through soil backfill behind the retaining wall “W”, and through tie-back elements such as polyester geogrid matting sandwiched between courses “C”. The setback spacer  28  locates the vertical spike  35  a spaced distance from the first end  26  of the course connector  25  to position the wall block  10  in the retaining wall “W” relative to the other blocks  10  in the upper and lower course “C”. The degree of setback is controlled by the length of the spacer  28 . For example, a relatively short setback spacer  28  will result in greater setback from one stacked course to the next. A longer setback spacer  28  will result in less setback. 
     In alternative embodiments (not shown), the course connector may have a first end which extends in only a single x or y-direction, as previously defined, or which is hooked to hold the course connector in the wall block. The second end of the course connector may include only a single free end which may or may not be pointed. In addition, the first and second ends may extend at respective obtuse or acute angles relative to the setback spacer. 
     Referring to FIGS. 1-3 and  9 , the top  14  of the wall block  10  defines a lateral tie-back channel  41  extending from one side of said block  10  to the other. The channel  41  is designed to receive a tie-back element, such as a flat elongated tie-back bar  42  shown in FIG.  9 . The tie-back bar  42  may span several wall blocks  10 , and resides inside the channel  41  between geogrid matting  44  and blocks  10  in an upper course “C”. The geogrid matting  44  anchors the blocks  10  to soil backfill behind the retaining wall “W”. Preferably, the edges defining the tie-back channel  41  are beveled to accommodate insertion of the tie-back bar  42  and geogrid matting  44 . In an alternative application, the tie-back element may be a elongated flexible tie-back strap (not shown) which extends through the channel  41  and rearwardly into the soil backfill. The back edge of each pair of edges defining respective vertical slots  21 ,  22  in the wall block  10  is preferably rounded to accommodate proper placement and use of the strap. After assembling the blocks  10 , as described above, a course of molded concrete wall caps (not shown) is preferably laid over the top course to finish the retaining wall. 
     A further embodiment of a wall block  50  according to the present invention is shown in FIGS. 10 and 11. The smaller block  50  is especially applicable in commercial and residential landscaping. Like wall block  10 , block  50  has a front  51  and rear  52 , top  53  and bottom  54 , and opposing sides  55  and  56 . The front  51  includes vertical breaks  57  and  58  defining a center face portion  51 A and opposing side face portions  51 B and  51 C. The core of the wall block  50  is hollow and the sides  55  and  56  are reduced relative to the front  51  and rear  52  to substantially reduce the overall weight of the block  50 . The sides  55 ,  56  define respective vertical, L-shaped slots  61  and  62  extending through the wall block  50  from the top  53  to the bottom  54 . The vertical slots  61 ,  62  receive mechanical course connectors, identical to the connector  25  described above, which operate to conveniently position, align, and secure the blocks  50  in a landscape wall. To further reduce weight and promote handling, the rear  52  of the block  50  may be broken off using a hammer or other suitable tool. The reduced sides  55 ,  56  allow increased placement of soil directly behind the front  51  of the block  50  to conceal a substantial portion of the top  53 , and to maximize the available surrounding space for plantings. 
     A wall block is described above. Various details of the invention may be changed without departing from its scope. Furthermore, the foregoing description of the preferred embodiment of the invention and best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation—the invention being defined by the claims.