Abstract:
A lightweight polymer-based load bearing platform preferably including artificial turf for use as a synthetic turf block for easy installation, easy maintenance, and long term durability.

Description:
STATEMENT REGARDING NOTICE OF COPYRIGHT 
     A portion of the disclosure of this patent document contains material which is subject to (copyright or mask work) protection. The (copyright or mask work) owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all (copyright or mask work) rights whatsoever. 
     FIELD 
     This disclosure relates to the field of paving and ground cover. More particularly, this disclosure relates to turf blocks for use as a form of pavement or groundcover. 
     BACKGROUND 
     Turf blocks or grass blocks are an environmentally preferable alternative to asphalt, full concrete pavement, or dirt for driveways, roadways, sidewalks and the like because these structures allow precipitation moisture to flow directly to the sub terrain and not create storm water runoff. Turf blocks are traditionally thought of as a repeating network of concrete squares (or diamonds) wherein the central section of the squares are hollow and filled with dirt and grass for a quasi-natural terrain wherein the natural portions are supported a kept from being compacted because of the support of surrounding concrete structure. 
     More recently, alternatives to concrete have been used to create turf block pavement. Nonetheless, although the grass sections are not overly compacted, the grass itself often dies or otherwise changes color due to seasonal stresses or death of the grass itself. Another drawback with many turf block applications is unevenness that develops over time due to the weight of vehicle or foot traffic on such materials. 
     What is needed, therefore, is an environmentally-friendly, lightweight, and cost-effective structure that accomplishes the functional purposes of traditional turf blocks while maintaining the aesthetic purposes of such turf blocks. 
     SUMMARY 
     The above and other needs are met by a lightweight load-bearing platform including a unitary polymeric base structure including at least a first sidewall, a second sidewall, a third sidewall, a fourth sidewall, a top plate, and a plurality of interior wall structures providing support under the top plate; a plurality of indentations along the top plate, an upper surface of each indentation defining an engagement surface, the engagement surface defining an area of A cm2; a plurality of apertures wherein at least one respective aperture is located through each one respective indentation; a first male attachment device located along an outer surface of the first sidewall; a second male attachment device located along an outer surface of the second sidewall; a first female attachment device located along an outer surface of the third sidewall; and a second female attachment device located along an outer surface of the fourth sidewall. The load-bearing platform may further include at least five full engagement surfaces, each full engagement surface defining the area of approximately A cm 2 ; and at least four half engagement surfaces, each half engagement surface defining an area of approximately (0.5)·A cm 2 . In some cases, the at least five full engagement surfaces comprise approximately identical shapes. In some cases, five separate sections of artificial turf are attached to each of the at least five full engagement surfaces, wherein the sections of artificial turf do not extend beyond the edge or edges of the respective full engagement surfaces. In some cases, the at least five full engagement surfaces include square shapes and the outer edges of the engagement surfaces are oriented substantially parallel to each other, thereby defining a crisscross pattern of bar shaped sections along the top plate. 
     In cases in which five separate sections of artificial turf are attached to each of the at least five full engagement surfaces, in certain situations, artificial turf does not extend beyond the edge or edges of the respective full engagement surfaces. 
     Load-bearing platforms as described above may further include at least four quarter engagement surfaces, each quarter engagement surface defining an area of approximately (0.25)·A cm 2 , and wherein the edges of the top plate define a substantially square shape. 
     In some cases, the plurality of interior wall structures further include a plurality of channels defined by channel wall structures oriented orthogonally from a lower surface of the top plate, wherein each channel wall structure extends from a respective area along the lower surface of the top plate within which one of the respective apertures is located, thereby providing a path for fluid to migrate from the upper surfaces of the indentations to locations below the load-bearing platform. In certain cases, the channels are formed in a cylindrical shape. In some cases, the first sidewall, the second sidewall, the third sidewall, and the fourth sidewall each further include six substantially planar sub-wall portions, and each adjacent pair of sub-wall portions are oriented at an interior angle ranging from about 135 degrees to about 270 degrees. In these situations, the plurality of interior wall structures can further include at least four branch walls extending at approximately 0 degrees, 90 degrees, 180 degrees, and 270 degrees from each of the channel wall structures and extending to adjacent channel wall structures. Also, the plurality of interior wall structures can further include at least eight branch walls extending at approximately 0 degrees, 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees and 315 degrees from at least one of the channel wall structures and, in such cases, the branch wall structures extending at approximately 45 degrees, 135 degrees, 225 degrees, and 315 degrees from the channel wall structures all can extend all the way to adjacent channel wall structures. 
     In some situations, a support pad including a base and a groove defined between a pair of pad sections is included, wherein the pad is removably attached along one of the interior wall structures. The groove is preferably defined orthogonal to the base whereby the pad can be removably engaged along the bottom of a load bearing platform by pressing a first side of the pad that includes the groove against an interior wall structure of the load-bearing platform such that the interior wall is jammed between the pair of pad sections. 
     In certain cases, the first female attachment device described above further includes an elongate slot extending from a bottom edge of the third sidewall to from about 20% to about 80% the height of the third sidewall. 
     In certain situations, the first female attachment device described above further includes a vertically oriented narrow appendage including a cap extending orthogonal from a distal end of the appendage, wherein the appendage extends outward from a bottom edge of the first sidewall to from about 20% to about 80% the height of the first sidewall. 
     In certain situations, the upper surfaces of the bar shaped sections described above have the appearance of a surface including, for example, concrete, brick, rock, or sand. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features, aspects, and advantages of the present disclosure will become better understood by reference to the following detailed description, appended claims, and accompanying figures, wherein elements are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein: 
         FIG. 1  shows a top perspective view of a load-bearing platform; 
         FIG. 2  shows a first side view of the load-bearing platform of  FIG. 1 ; 
         FIG. 3  shows a second side view of the load-bearing platform of  FIG. 1 ; 
         FIG. 4  shows a third side view of the load-bearing platform of  FIG. 1 ; 
         FIG. 5  shows a fourth side view of the load-bearing platform of  FIG. 1 ; 
         FIG. 6  shows a top plan view of the load-bearing platform of  FIG. 1 ; 
         FIG. 7  shows a top perspective view of a plurality of load-bearing platforms of  FIG. 1  removably attached together; 
         FIG. 8  shows a bottom perspective view of the load-bearing platform of  FIG. 1 ; 
         FIG. 9  shows a bottom plan view of the load-bearing platform of  FIG. 1 ; 
         FIG. 10  shows a bottom plan view of a plurality of load-bearing platforms of  FIG. 1  removably attached together including a plurality of pads attached along the bottoms of some of the load bearing platforms; and 
         FIG. 11  shows an example of a pad as shown in  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION 
     Various terms used herein are intended to have particular meanings. Some of these terms are defined below for the purpose of clarity. The definitions given below are meant to cover all forms of the words being defined (e.g., singular, plural, present tense, past tense). If the definition of any term below diverges from the commonly understood and/or dictionary definition of such term, the definitions below control. 
     About: indicates a range of variation of a given value of up to 5% of the given value. 
     Approximately: indicates a range of variation of a given value of up to 5% of the given value. 
     Substantially: indicates a range of variation of a given value of up to 2% of the given value. 
       FIG. 1  shows a perspective view of an example of a lightweight load-bearing platform  10  as described herein. The load-bearing platform  10  includes a top plate  12  which includes a plurality of indentations  14 A- 14 M. Each of the indentations  14  defines an engagement surface  16 A- 16 M. Each indentation  14  includes at least one aperture  18  located therethrough.  FIG. 2  shows a first side view of the load-bearing platform  10  showing a first sidewall  20  including a first male fastener  22 .  FIG. 3  shows a second side view of the load-bearing platform  10  showing a second sidewall  24  including a second male fastener  26 .  FIG. 4  shows a third side view of the load-bearing platform  10  showing a third sidewall  28  including a first female fastener  30 . Similarly,  FIG. 5  shows a fourth side view of the load-bearing platform  10  showing a fourth sidewall  32  including a second female fastener  34 . 
       FIG. 6  shows a top plan view of the load-bearing platform  10 , giving a clearer view of an example of a preferred geometric pattern of indentations  14  along the top plate  12 . The top plate  12  shown in  FIG. 6  includes five full engagement surfaces  16 A- 16 E, each defining an area of from about 80 cm 2  to about 100 cm 2 , and more preferably from about 85 cm 2  to about 95 cm 2 . Preferably, the engagement surfaces have substantially the same shape and such shapes are preferably substantially aligned with one another in a regular repeating pattern to give the appearance of traditional square or diamond turf blocks, although other shapes and configurations are contemplated herein. Sections of artificial turf are preferably attached to the engagement surfaces  16  wherein such sections of artificial turf are preferably sized and shaped to fit adjacent to each engagement surface  16  without overlapping the edges of each engagement surface  16 . The example shown in  FIG. 1  shows a crisscross pattern of bar-shaped sections  36  along the top plate between the indentations  14 . The bar-shaped sections  36  resemble the traditional concrete used in traditional turf block applications. 
     The top plate  12  shown in  FIG. 6  also includes four half engagement surfaces  38 A- 38 D and four quarter engagement surfaces  40 A- 40 D. When multiple load-bearing platforms  10  are to attached together as shown in  FIG. 7 , the half engagement surfaces  38  and the quarter engagement surfaces  40  come together to form full engagement surfaces  42 . In this way, the pattern provided on the top plate  12  can be repeated as many times as necessary depending on the size of the area to be covered by the load-bearing platforms  10 . The load-bearing platforms engage with one another via the first male fastener  22 , the second male fastener  26 , the first female fastener  30 , and the second female fastener  34  wherein a male fastener slides into or otherwise attaches to an adjacent female fastener as shown in  FIG. 7 ,  FIG. 8 , and  FIG. 9 . In the example shown in  FIGS. 1-9 , the first male fastener  22  includes two hitches  44 A and  44 B, the second male fastener  26  includes two hitches  46 A and  46 B, the first female fastener  30  includes two notches  48 A and  48 B, and the second female fastener  34  includes two notches  50 A and  50 B. 
       FIG. 8  and  FIG. 9  show a bottom view of the load-bearing platform  10  including a plurality of interior wall structures  52 . The interior wall structures  52  include a plurality of channels  54  defined by channel wall structures  56  oriented orthogonally from a lower surface  58  of the top plate  12 , wherein each channel wall structure  56  extends from a respective area along the lower surface  58  of the top plate  12  within which one of the respective apertures  18  is located. The channels  54  allow for fluid that temporarily accumulates along the indentations  14  to escape through the apertures  18  and down through the channels  54  to a space beneath the load-bearing platform  10 , thereby providing similar functionality as that of a traditional concrete turf block including grass and soil. 
     The first sidewall  20 , the second sidewall  24 , the third sidewall  28 , and the fourth sidewall  32  each further include six substantially planar sub-wall portions including sub-wall portions  20 A- 20 F, sub-wall portions  24 A- 24 F, sub-wall portions  28 A- 28 F, and sub-wall portions  32 A- 32 F wherein sub-wall portions  20 A and  32 F are one in the same, sub-wall portions  20 F and  24 A are one in the same, sub-wall portions  24 F and  28 A are one in the same, and sub-wall portions  28 F and  32 A are one in the same. In the embodiment shown in  FIG. 8 , each adjacent pair of sub-wall portions are oriented at an interior angle ranging from about 135 degrees to about 270 degrees as shown, for example, by angle θ  60  and angle λ  62 . The interior wall structures  52  also include branch walls  64  extending at approximately 0 degrees ( 64 A), 45 degrees ( 64 B), 90 degrees ( 64 C), 135 degrees ( 64 D), 180 degrees ( 64 E), 225 degrees ( 64 F), 270 degrees ( 64 G) and 315 degrees ( 64 H) from each of the channel wall structures  56 . Branch wall  64 A, branch wall  64 C, branch wall  64 E, and branch wall  64 G all extend directly to adjacent channel wall structures  56 . 
       FIG. 10  shows a bottom view of a plurality of load bearing platforms  10 A- 10 E fastened to one another. A plurality of pads  66  are shown attached to interior wall structures  52 . Each pad  66 , as shown in  FIG. 11 , preferably includes a groove  68  defined orthogonal to a base  70  (preferably a planar-shaped member) so that the pads can be removably engaged along the bottom of a load bearing platform by pressing the groove  68  side of a pad  66  against an interior wall structure  52  such that an interior wall  52  is jammed between a pair of pad sections  72  oriented substantially orthogonal to the base  70 , defining the groove  68 . The pads  66  help distribute force exerted against the load bearing platform  10  down to the planar members  70 . The pads  66  also help hold groups of joined load bearing platforms to remain stationary relative to any surface on which such load bearing platforms are laid. The pads  66  are preferably made by molding techniques such as blow molding, and are preferably made of a composition primarily including polymers, co-polymers, or polymer blends including, for example, polyvinyl chloride, polyethylene, polypropylene or combinations thereof. 
     The sidewalls ( 20 ,  24 ,  28 ,  32 ) and interior wall structures  52  provide support for the top plate  12 , preferably providing a compressive strength ranging from about 10 megapascals (MPa) to about 80 MPa or greater for the load-bearing platform. This level of compressive strength allows for a set of attached load-bearing platforms  10  to support automobiles and similarly weighted materials without substantial deformation. The load-bearing platforms  10  can also be used in other pavement type applications such as, for example, walkways, gardens, outdoor play areas, and any area that is prone to soil compression and the accumulation of fluid from runoff and/or direct precipitation. 
     The load-bearing platforms  10  are preferably manufactured by blow-molding or other molding techniques, and are made of a composition primarily including polymers, co-polymers, or polymer blends including, for example, high density polyethylene, polypropylene, or combinations thereof. 
     Finished artificial turf sections can be attached to the engagement surfaces  16  during to manufacturing using, for example, an adhesive. Additional artificial turf sections can then be provided for a contractor, retail customer, or other end user to attach to the engagement surfaces  42  after a plurality of load-bearing platforms  10  have been attached together and laid in place. Alternatively, a contractor, retail customer, or other end user can select from a variety of colors and styles of artificial turf sections to attach to a load-bearing platform  10 . Additionally, the bar-shaped sections  36  can include a surface texture and/or coloration resembling concrete, brick, rock, sand, or other similar materials based on using different manufacturing molds and altering dyes used to formulate the underlying polymeric composition. 
     The previously described embodiments of the present disclosure have many advantages, including maintaining the aesthetic features and functionality (minimize pavement compression, maximize fluid flow to subsurface levels) of traditional forms of turf blocks while providing a significantly lighter, easily recyclable product that is much easier to maintain, alter, manipulate and/or remove if needed. For example, instead of carefully placing five concrete blocks in place, filling them with soil and grass, and then maintaining the grass, a person can simply lay a single load-bearing platform  10  as shown in  FIG. 1  and accomplish the same work. Moreover, the load-bearing platforms  10  are readily attachable to and detachable from one another. 
     The foregoing description of preferred embodiments of the present disclosure has been presented for purposes of illustration and description. The described preferred embodiments are not intended to be exhaustive or to limit the scope of the disclosure to the precise form(s) disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments are chosen and described in an effort to provide the best illustrations of the principles of the disclosure and its practical application, and to thereby enable one of ordinary skill in the art to utilize the concepts revealed in the disclosure in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the disclosure as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.