Abstract:
An inner mold body includes a first pair of side walls opposite one another, each of the first pair of side walls having a pair of engagement members attached thereto, a second pair of side walls opposite one another; wherein each of the second pair of side walls is adjacent to each of the first pair of side walls, and a separation mechanism in contact with each of the second pair of side walls.

Description:
BACKGROUND INFORMATION 
       [0001]    Much of the world&#39;s population lacks access to potable water. Filtration devices can be made from a variety of materials. One useful material for making water filters is concrete. A rectangular concrete water filter, filled with sand and gravel, can be used to create an anaerobic environment that both filters particles from contaminated water, as well as kills pathogens. 
         [0002]    However, concrete is heavy and therefore difficult and expensive, if not impractical, to transport. Further, molds that would allow concrete to be poured in remote locations for making water filters are also difficult to transport and/or are generally complicated to assemble and use. Such molds are generally made from heavy and expensive materials such as steel, limiting the ability to provide water filters, or the materials to make water filters, to economically disadvantaged regions, remote locations, and other areas lacking potable water. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]      FIG. 1  provides an exemplary perspective view of a mold. 
           [0004]      FIG. 2  provides an exemplary cross-sectional view of the mold of  FIG. 1 . 
           [0005]      FIGS. 3A and 3B  provide perspective views of inner body walls of the mold of  FIG. 1 . 
           [0006]      FIGS. 4A and 4B  provide side views of sidewalls of an inner body of the mold of  FIG. 1 . 
           [0007]      FIG. 5A  provides an exemplary perspective view of an upper portion of the inner body of the mold of  FIG. 1  with the side walls of the inner body secured in place. 
           [0008]      FIG. 5B  provides an exemplary perspective view of an upper portion of the inner body of the mold of  FIG. 1  with a dagger board removed and side walls collapsed. 
           [0009]      FIGS. 6A and 6B  provide a side views of an exemplary dagger board for the mold of  FIG. 1 . 
           [0010]      FIG. 7  provides a bottom view of an exemplary cap for the inner body of the mold of  FIG. 1 . 
           [0011]      FIG. 8  illustrates an alternative implementation of the mold of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0012]      FIG. 1  illustrates a perspective view, and  FIG. 2  illustrates a cross-sectional view, of an exemplary mold  10 , including an outer body  12 , an inner body  14 . As seen in  FIG. 1 , a cap  22  is generally provided to be fitted over the inner body  14 . When the outer body  12  is placed around the inner body  14 , and the cap  22  is in place, the mold  10  may be used, e.g., for pouring and curing concrete or the like. 
         [0013]    The outer body  12  is generally formed by four generally rectangular walls  13  connected together so that a cross-section of the outer body  12  is rectangular, preferably square or approximately square. In one example, the walls  13  are each approximately thirty-six inches long by approximately sixteen inches wide. Further, the walls  13  in this example are approximately ¾ inch thick, and in general walls  13  are preferably in a range of ⅜ to 1 inch thick. The walls  13  generally have sides cut at angles  36  of about forty-five degrees) (45°) to allow the walls  13  to be joined together to form a rectangular cross-section. Mechanisms used for fastening the walls  13  to one another may include various screws, or other fastening mechanisms. Walls  16  are generally made from laminated particle board, e.g., such as may be purchased from many retail lumberyards or the like. Laminated plywood may also be used, and use of marine grade plywood generally will result in improved production life of the mold  10  at only a marginally higher construction cost. In general, the mold  10  is preferably made from materials that are relatively lightweight and easy to transport. 
         [0014]    The inner body  14  includes sidewalls  16  and  18 , held in place by one or more straps  15  during assembly, afterwards held in place by friction, and rests on a base  20 . A dagger board  24  is disposed within the interior of the inner body  14 . The inner body  14  may be attached to the base  20  using screws, adhesives, and/or other fastening mechanisms. The dimensions of the base  20  are generally slightly larger than the dimensions of a cross-sectional shape, e.g., square, formed by the outer body  12  so as to allow the outer body  12  to rest on the base  20  when the outer body  12  is placed around the inner body  14 , e.g., when concrete is being poured. 
         [0015]      FIGS. 3A and 3B  provide perspective views of the inner body  14  walls  16  and  18 .  FIGS. 4A and 4B  provide side views of an inner body  14  side wall  16 , and  FIGS. 4C and 4D  provide a side views of an inner body  14  side wall  18 . 
         [0016]    Wall  16  includes two engagement members  26  attached, e.g., using hinges or the like, to a main member  27 . As seen in  FIG. 3A , the engagement members  26 , at an open position, extend perpendicularly or approximately perpendicularly from the main member  27 .  FIG. 4A  shows the engagement members  26  in an open position, sometimes referred to as an engaged position.  FIG. 4B  shows the engagement members  26  in a closed, or relaxed, position. As discussed further below, the engagement members  26  may be in an engaged position when concrete is poured into, and is curing and, the mold  10 . Further, the engagement members  26  may be relaxed so that the inner body  14  may be removed from a concrete structure once the concrete structure has cured in the mold  10 . Hinging the engagement members  26  generally allows improved production life of the mold  10  and reduces the possibility of the inner body  14  being difficult to release after concrete poured into the mold  10  has cured. However, that implementations that omit a hinge and any hinge-like elements are possible. In such implementations, the engagement members could be glued, screwed, or otherwise attached, to the main member  27  as shown in  FIG. 3A , and would remain in the open position shown, e.g., in  FIGS. 3A ,  4 A, and  5 A, and would not moved toward a relaxed position as shown in  FIGS. 4B and 5B . 
         [0017]    The walls  16  and  18  are generally of a thickness the same as or similar to the thickness of walls  13 , discussed above. Further, dimensions of the members  26  and  27  may vary, e.g., to continue the example discussed above, the members  26  and  27  may each be approximately 32-34 inches long, e.g., thirty-three and five-eights inches long. Further, the member  27  may be 8-10 inches wide, e.g., eight and five-eighths inches. The members  26  may each be 1.125-2.0 inches wide, e.g., 1.25 inches. 
         [0018]    As seen in various figures, members  27  may have beveled edges meeting the sides of engagement members  26 . Bevels in the edges of the members  27  are optional, but provide the benefit of allowing the side walls  16  to release more cleanly, quickly, and/or easily from a cured concrete structure formed in the mold  10 . 
         [0019]    As shown in  FIGS. 3B ,  4 C, and  4 D, wall  18  includes an inner member  28  and an outer member  30 . The wall  18  also may include guides  32  for positioning the dagger board  24 , as discussed further below. The members  28  and  30  may be mounted onto one another with their respective centerlines aligned or substantially aligned, and the guides  32  may be mounted on the member  28 , via screws, adhesives, or some other suitable fastening mechanism. 
         [0020]    The outer member  30  is generally of a length that is similar to the lengths of members  26  and  27 . The inner member  28  is generally shorter than the outer member  30  by a certain amount, e.g., four inches. As can be seen in  FIGS. 1 ,  2 , and  5 , a top edge of the inner member  28  is generally mounted substantially flush with a top edge of the outer member  30  such that the sum of the width of two members  26  and one member  30  is approximately the same as the overall width of one member  27 , resulting in an approximately square shape of the inner body  14 . Further; member  28  is constructed in such a way that its width is less than the sum of the two members  26  and member  30  so that any compression from external forces (e.g. concrete curing/or pouring) is transmitted to engagement members  26  and outer member  30  externally, rather than  28  inner member  28  transmitting force to outer member  30 , which could allow uncured concrete to leak into the interior of the inner body  14 , which could make disassembly of the inner body  14  more difficult. 
         [0021]    The width of the outer member  30  is determined by the widths of the members  26  with which the outer member  30  is fitted. For example, if the members  26  are each about 1.125 inches wide, then the outer member  30  should be about 5.5 inches wide. 
         [0022]    The inner member  28  is generally wider than the outer member  30 , the outer member  30  generally being mounted in the center, or a long a dividing line, of the inner member  28 . For example, if the outer member  30  is 5.5 inches wide, then the inner member  28  may be 7.875 inches wide. 
         [0023]    As best seen in  FIG. 2 , outer member  30  of side wall  18  and members  26  of side wall  18  are angled in a complementary manner so that the members  30  and  26  may about each other at a seam  40 , whereby the members  26  in a closed position secure the side wall  18 . In one embodiment, the sides of the members  26  and  30  are angled at or about ten degrees (10°). Thus, when viewed in cross-section as in  FIG. 2 , outer member  30  is a trapezoid, with the longer face of the trapezoid being the face that abuts inner member  28 . 
         [0024]      FIG. 5A  provides an exemplary perspective view of an upper portion of the inner body  14  with the side walls  16  and  18  secured in place, where the members  26  of walls  16  respectively abutting outer members  30  of walls  18  at seams  40 , as discussed above, and also abutting, on inner faces of the respective walls  26 , respective outer faces of inner members  28  of walls  18 . Dagger board  24 , held in place by guides  32 , prevents members  26  from moving toward a closed position, and the side walls  18  from moving toward one another. Alternatively, guides  32  could be omitted, and the dagger board  24  could be held in place by friction. In any case, the dagger board  24  is generally situated between the members  26 . Further other separation mechanisms could be used in place of the dagger board  24  to separate the members  26 , preferably a mechanism such as a four-bar rocker or the like that would allow the members  26  to be relaxed to a closed position once concrete poured into the mold  10  had cured. 
         [0025]    Side walls  18 , by abutting members  26 , in turn prevent side walls  16  from collapsing toward one another. Inner body  14 , once arranged as shown, e.g., in  FIGS. 1 , and  5 A, may be secured by various mechanisms, e.g., one or more straps  15 , e.g., cloth or metal bands, etc., may be placed around the outer surfaces of the inner body  14  during assembly to support the inner core. The straps  15 , if used, are generally removed before concrete is poured into the mold  10 . 
         [0026]      FIG. 5B  provides an exemplary perspective view of an upper portion of the inner body  14  with the dagger board  24  removed. As is shown, in the absence of the dagger board  24  bracing apart side walls  18 , side walls  18  can be collapsed toward one another, whereby members  26  of side walls  16  collapse to a closed or disengaged position. Further, as side walls  18  are collapsed toward one another, or removed from the interior of a concrete structure, side walls  16  may likewise be collapsed toward one another for removal from the concrete structure. 
         [0027]      FIG. 6A  illustrates a side view of sections  34  an exemplary dagger board  24 , although it is to be understood that dagger board  24  could be a single substantially rectangular piece, instead of two substantially triangular sections  34  that are mated to form dagger board  24 . For example, a single-piece dagger board  24  could be used in cases where guides  32  are omitted. Further, as mentioned above, other mechanisms, such as a four-bar rocker, could be used in place of the dagger board  24 . The split (two piece) dagger board  24  allows a rapid release of compressive stresses on the center core while the concrete cures and reduces the possibility of dagger board being trapped if members  18  or  16  become misaligned while concrete poured into the mold  10  is curing. Dagger board  24  sections  34  generally have a length about the same as the length of members  28  of side wall  18 . Two holding members are affixed to respective sides of dagger board  24  pieces  34 , e.g., via screws or the like. Only one holding member  35  is visible as mounted on each section  34  as seen in  FIG. 6  because the other holding member  35  for each section  34  is obscured by the visible holding member  35 . The holding members  35  slightly engage and hold in place, by friction, the sections  34 , that when placed together as shown in  FIG. 6B , form a single dagger board  24 . 
         [0028]      FIG. 7  illustrates an example of a bottom face of the cap  22 , including four guides  38  arranged so that the cap  22  may be placed on the inner body  14 , the guides  38  serving to properly locate and hold in place the cap  22  with respect to the side walls  16  and  18  of the inner body  14 . Accordingly, dimensions of the cap  22 , and the placement of guides  38 , are determined according to dimensions and the arrangements of side walls  16  and  18 . 
         [0029]      FIG. 8  illustrates an alternate implementation of the mold  10  of  FIG. 1 . As seen in  FIG. 8 , a sleeve  17  may rest on the base  20 , and may be affixed thereto, e.g., using screws or the like. The inner body  14 , once assembled, may be placed in the sleeve  17 . The purpose of the sleeve  17  is to allow for creation of a ledge or step in the interior walls of a concrete structure created using the mold  10 . This ledge may be used to retain and/or support a screen, sieve, or other structure on which gravel, metal chunks, nails, etc. may be placed. Such a ledge may thereby provide for a diffuser or some other pre-treatment mechanism to be used in a concrete biosand filter made using the mold  10 . Generally, the sleeve  17  should be constructed in such a fashion that it will fit snugly around the inner body  14 , i.e., friction should hold the nearby  14  in place in the sleeve  17 , but it should be possible to lift the inner body  14  from the sleeve  17 , or to lift the base  20  with the attached sleeve  17  from the inner body  14  after turning the inner body  14  upside-down. The height of the sleeve  17  may be varied for various applications, but in many implementations the sleeve  17  extends approximately  6  inches from the base  20 . 
         [0030]    The mold  10 , in addition to being generally made of light-weight, relatively easily transported materials, is also generally relatively easy to assemble and use. A process by which the mold  10  may be used is as follows. The mold  10  may be assembled generally as shown in  FIG. 1 , with the cap  22  placed on the inner body  14  as described above. Then, the outer body  12  may be placed on the base  20  such that the outer body  12  is around the inner body  14 .  FIG. 2  provides a cross-sectional view of the resulting arrangement, except that the cap  22  is not shown. Next, concrete may be poured into the mold  10 , and allowed to cure. Once the concrete is cured, the cap  22 , and then the dagger board  24 , may be removed from the inner body  14 , whereupon the inner body  14  may be collapsed, e.g., as shown in, and described above with respect to,  FIG. 5B . Side walls  16  and  18  of the inner body  14  may then be removed from the interior of the concrete structure formed by the mold  10 . Further, the outer body  12  may be removed, leaving a concrete structure that may be used for a desired purpose, e.g., as a water filter. Concrete contracts during curing, further facilitating the removal of the outer body  12  and the inner body  14  from the concrete structure. 
         [0031]    It is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments and applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the invention should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future embodiments. In sum, it should be understood that the invention is capable of modification and variation and is limited only by the following claims. 
         [0032]    All terms used in the claims are intended to be given their broadest reasonable constructions and their ordinary meanings as understood by those skilled in the art unless an explicit indication to the contrary in made herein. In particular, use of the singular articles such as “a,” “the,” “said,” etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary.