Abstract:
An assembly of precast concrete units matingly assembled on top of one another to form a whole deck footing, capable of supporting a deck, shed, porch, addition or other structure. The individual units are of manageable weight and can be moved by one person, not unlike a bag of unmixed cement. The units interlock to prevent shifting, separating, frost damage by water infiltration and heaving when placed under ground.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/213,975, filed Aug. 4, 2009, which priority application is herein incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to an assembly of precast concrete units, mateingly assembled on top of one another to form a whole deck footing for supporting structures. 
       BACKGROUND OF THE INVENTION 
       [0003]    Currently several techniques for creating deck footings exist. One type is to excavate the ground, place a round cardboard tube in the hole, level the tube and back fill around the tube. The tube is then filled with concrete and let it cure for an amount of time. The cardboard tubes that are currently in use are susceptible to rain and can warp when dirt is backfilled around the tube. Another type of footing currently in use is a solid precast pier. It can weigh 450 pounds or more and requires the use of heavy equipment to move. 
       SUMMARY OF THE INVENTION 
       [0004]    Wherefore, it is an object of the present invention to overcome the above mentioned shortcomings and drawbacks associated with the prior art. 
         [0005]    Another object of the present invention is to eliminates the need for placement of cardboard tubes or other means of forming deck footings or pilings for structure support. This invention is a simpler and more earth friendly approach. It eliminates the need for mixing quantities of concrete to fill said forms and eliminates the need to wait for the concrete to set up. Because the individual precast units in this invention are of manageable weight no equipment is necessary to place the footings, the cost is reduced and almost anyone is capable of placing these footings. This invention will be easier to level than the current technology because the footing unit can be placed and leveled before the upper stacking units are added, as opposed to the current technology that requires placing and leveling an entire 450 pound unit. This invention is also superior to a cardboard tube, as, unlike cardboard tubes, this invention is not susceptible to damage caused by rain and will also remain level when back filled. The quality of the invention is precast footings will be more manageable, and thus ensure a better end product than a pour in place cardboard tube. This invention also solves the problem of storage for retailers. This invention can be exposed to the elements without damage, where as damage results when cardboard tubes or bags of concrete mix are left in the elements. 
         [0006]    The present invention also relates to an assembly for supporting structural weight comprising, at least two stacking units substantially identical in shape, wherein an upper portion of an at least one first stacking unit fits securely into a recess defined in the lower portion of an at least one second stacking unit and securing means for securing the at least one first stacking unit to the at least one second stacking unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is an exploded depiction of the assembled unit. 
           [0008]      FIG. 2  is a drawing of a stacking unit. 
           [0009]      FIG. 3  is a bottom view of a stacking unit. 
           [0010]      FIG. 4  is a drawing of a stacking unit. 
           [0011]      FIG. 5  is a drawing of a stacking unit. 
           [0012]      FIG. 6  is a drawing of an anchor. 
           [0013]      FIG. 7  is a drawing of an anchor. 
           [0014]      FIG. 8  is a drawing of the stacking and footing units with precast threaded inserts. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    With reference now to  FIGS. 1-8 , a detailed description concerning the assembly  2  of the present invention will now be provided. As can be seen in  FIG. 1 , for example, the assembly  2  is generally comprised of a plurality of stacking units  4 , a footing unit  6 , and an anchor  8 . 
         [0016]    The stacking units  4  are substantially identical in size and shape and each stacking unit  4  has an upper portion  10  that matingly fits into a recess  12  in the lower portion of another stacking unit  4 . This mating fit speeds assembly by automatically aligning one stacking unit  4  to another, and adds structural integrity to the assembled assembly  2  by providing resistance to lateral movement of the stacking units. Generally, the top of the upper portion  10  of the stacking unit  4  is flat to accommodate a support beam for a structure, but this is not necessary. The sides of upper portion  10  may be either vertical or diagonal or, as shown in  FIGS. 1 and 2 , both vertical and diagonal. 
         [0017]    The outer perimeter of the stacking units  4  can be a variety of shapes and still function in the inventive capacity. Contemplated shapes of the stacking units  4  are circular, square, elliptical, rectangular, triangular, or hexagonal, and other bilaterally symmetric shapes. It is to be noted that the stacking units  4  need not be of a bilaterally symmetric shape to still function in the inventive capacity. Additionally, the units could interlock in a variety of ways, including a tapered top sleeving into a receiving bottom. 
         [0018]    The footing unit  6  has a flat base  16  that is wider than the base of the staking units  4  and has an upper portion  14  that is sized to also fit matingly into the recess  12  in the lower portion of a stacking unit  4 . The base  16  of the footing unit  6  may have a similar or different shape as the stacking unit  4 . The sides of the footing unit  6  slope to allow water to run off the footing unit  6 , as it is wider than the stacking units  4  and is a potential trap for water. While it is generally preferred to use the footing unit  6  in the assembly  2 , the assembly  2  may be assembled with only a plurality of stacking units  4  and an interlocking means and still possess the inventive aspect of the present invention. The diameter of the stacking units  4  and the footing unit  6  may vary to accommodate the residential or construction use. 
         [0019]    Turning to  FIGS. 6 and 7 , the anchor  8  is comprised of a rod  30 , with a first end  32  and a second end  34 . The first end  30  has a first threaded section  36 , and depending on the embodiment, the second end  34  may have a second threaded section  38 . The rod  30  is sized to fit within an axial through channel  22  that runs through the stacking units  4  and base unit  6 . The rod  30  is of a sufficient length such that when the assembly  2  is assembled, the rod  30  reaches from base  16  of the footing unit  6  to above the upper portion  10  of the top most stacking unit  4 . An alternate embodiment, not show, has the rod  30  threaded completely from the first end  32  to the second end  34 . 
         [0020]    The function of the anchor  8  is to vertically fix and provide compression force on the assembled units and to provide added lateral support to prevent the units from shifting. This is achieved by first passing the rod  30  through the axial through channel  22  of the assembled units, then securing the first end  32  of the rod  30  above the top of upper portion  10  of the top most stacking unit  4 , and then securing the second end  34  of the rod  30  below the base  16  of the footing unit  6 . The first end  32  of the rod  30  is generally secured by screwing an appropriately sized washer and nut  20  onto the first threaded section  36  of the first end  32  of the rod  30  which protrudes above the upper portion  10  of the top most stacking unit  4 . It is to be noted that the various methods to secure the second end  34  of the rod  30 , listed below, may also be used to secure the first end. 
         [0021]    The second end  34  of the rod  30  may be secured by a variety of methods, some described below. In one embodiment, the second end  34  of the rod  30  is pre-welded to a flat metal plate  40 . In another group of embodiments, the second end  34  of the rod  30  has a second threaded section  38 . This second threaded section  38  may be secured by screwing an appropriately sized washer and nut  20  onto the second threaded section  36  that extends out of the lower opening of the axial through channel  22  of the lower most unit. In another embodiment, the nut  20  could be precast into the axial through channel  22  of the footing unit  6 , and then the rod  8  would be screwed into the footing unit  6 . 
         [0022]    Additionally, a flat metal plate  40  with a through hole  42  may be used in conjunction with an appropriately sized washer and nut  20 , mounting the metal plate  40  onto second end  34  of the rod  30 , and then screwing the nut  20  onto the second threaded end  36  of the rod  30 . This metal plate may be in any shape, though, because of ease of production, circular and square/rectangular shapes are preferred. In a variation of this embodiment, the nut  20  is pre-welded onto the metal plate  40 , aligned with and underneath the through hole  42  in the metal plate  40 . In another embodiment, the flat metal plate  40  has a threaded hole  43 , appropriately sized to fit the second threaded section of the second end of the rod, and the flat metal plate  40  would screw directly onto the rod  30 . In a variation of this embodiment, the nut  20  is pre-welded onto the metal plate  40 , aligned with and underneath the threaded hole  43  in the metal plate  40 . 
         [0023]    With the embodiments that utilize a flat metal plate, a central portion of the base  16  of the footing unit  6  generally will have a recess  18  sized so that that the flat metal plate  40  fits securely within the recess  18 . This allows the anchor  8  to more securely attach to the units. Additionally with the embodiments that utilize a flat metal plate  40 , the recess  12  in the lower portion of the stacking unit  4  will be sized so that that the flat metal plate  40  fits securely within the recess  12 . This preserves the option of using a flat metal plated  40  anchor  8  in an assembly  2 , without also requiring the use of a footing member  6 . 
         [0024]    As an alternative to using an anchor for securing the units together, in other embodiments the units are designed to fixedly screw one to another. One embodiment of this design is shown in  FIG. 8 , where a male threaded insert  44  is cast into the bottom of the stacking unit  4 . Additionally, a female threaded insert  46  is cast into the upper portion  10  of the stacking unit and a female threaded insert  48  is cast into the upper portion  14  the footing unit  6 . The male threaded insert  44  and the female threaded inserts  46 , 48  are sized to fit matingly together, such that when a stacking unit is placed on top of a footing unit or another stacking unit and rotated, one unit will screw into another until the two units are securely attached. The threaded inserts  44 ,  46 ,  48  can be threaded cups constructed of metal and/or plastic. 
         [0025]    The stacking units  4  and footing units  6  are generally formed of precast concrete, but may be built of other materials that provide sufficient structural strength, such as wood composites, plastics, metals, and flyash. The stacking units  4  and footing units  6  are sized to be maneuverable by an adult man of average strength, with each stacking unit  4  being generally between 20 and 90 pounds, and preferably between 50 and 80 pounds in weight, and each footing unit  6  being generally between 30 and 140 pounds, and preferably between 70 and 120 pounds in weight. As shown in  FIG. 4 , and the preferred embodiment of  FIG. 5 , to increase maneuverability the stacking units  4  and footing units  6  may include a variety of precast handles  50 . Generally units formed from concrete will contain structural support in the form of wire mesh, galvanized pipe or rebar cage precast into the units. 
         [0026]    Though the tight fitting arrangement of the assembly  2  acts to prevent water from coming between the units, the stacking units  4  and footing units  6  may further include a water barrier  28  between the units. The water barrier  28  may be in the form of a water proofing membrane fixedly attached to some or all of the outer surface of the units, which will act to stop water infiltration between each of the units. The membrane can act as a seal when the units are placed together and compression force is applied. It is contemplated that one possible use for the assembly  2  will require it to be at least partially below ground, and the water barrier  28  will help prevent ground water from seeping between the below ground units. 
         [0027]    To use the assembly  2 , the necessary size of the assembly  2  must be determined, including any height and diameter requirements or restrictions. Generally, for each column or deck footing required, a contractor will procure the appropriate size and number of stacking units  4  and footing units  6  so that once assembled, the assembly  2  will be of correct height for the deck footing or other structural requirement. Next, the contractor will procure one threaded flat metal plate  40 , one nut  20 , one washer, and one rod  30  for each assembly to be assembled, the rod  30  sized to be a few inches longer that the height of the assembled assembly  2 . The contractor will dig an appropriately sized hole, and place and level the footing unit  6  in the hole, with the rod  30  and the attached flat metal plate  40 , and sleeved through the axial through channel  22  of the footing unit  6 . Next, the contractor will add additional stacking units  4  until the desired height is reached. Finally, the contractor will place the washer and nut  20  onto the first threaded section  36  of the first end  32  of the rod  30 , and screw the nut  20  down until the sufficient compression force is applied.