A stationary container with straight, vertical walls and an open top has a bottom frame with an array of holes through which closely packed support cells can slide so that the base of the container roughly contours to the surface on which it is set while maintaining a level top surface. This arrangement allows the load of a contained fluid material to be applied normal to the top of each support cell, distributing the vertical load over multiple points between the bottom of the container and the load-bearing surface on which the container is set. The support cells may be solid, hollow, or have openings to allow fluid to pass between the interior and exterior of the container. The container walls are vertical and attach to adjustable corner posts. The container may have a second frame, with or without holes, positioned above the support cells in order to provide additional support for the container walls, distributed support for additional loads applied to the top of the filled container, downward stabilizing support for the load, or a conduit for a second fluid.

RELATED APPLICATIONS  
       [0001]    This Application claims the benefit of U.S. Provisional Patent Application No. 60/389,472, filed Jun. 18, 2002. 
     
    
     
       TECHNICAL FIELD  
         [0002]    The present invention relates generally to containers and platforms, and more specifically to applications where the container or platform base load is to be distributed evenly over an unlevel surface.  
         BACKGROUND  
         [0003]    A common container or platform that is constructed with a rigid floor or base transfers the gross weight of the container or platform to a solid surface at three primary points, maximizing the pressure at these particular points. Adjustable support posts at multiple points might be added to such a container or platform to help distribute the load over a greater area, however, as the number of support posts increases, the cost of construction and installation also increases. For applications in which the load-bearing surface is arbitrarily unlevel and has limiting load pressure requirements such as rooftops or unstable ground, a large number of pressure points for a given container or platform is desired in order to minimize the pressure at any single point.  
           [0004]    The present invention addresses this problem by integrating multiple floating elements or cells into the base of a container, thus reducing the maximum load pressure, total weight, and cost of a container that is to be installed on a surface with limited load capabilities.  
         SUMMARY OF THE INVENTION  
         [0005]    In one embodiment of the present invention, a stationary container with straight, vertical walls and an open top has a bottom frame with an array of holes through which closely packed support cells can slide so that the base of the container roughly contours to the surface on which it is set. The container walls are held vertical, level and of even height by adjustable corner support posts. This arrangement allows the load of a contained fluid material to be applied normal to the top of each support cell, distributing the vertical load over multiple points between the bottom of the container and the solid load-bearing surface with which it comes in contact. The container may have a second frame, with or without holes, positioned above the support cells in order to provide additional support for the container walls, distributed support for additional loads applied to the top of the filled container, downward stabilizing support for the load, or a method of transporting a second fluid to various points within the container.  
           [0006]    In another embodiment of the invention, a container assembly comprises a horizontal base frame with holes through which support cells can move vertically. A closely packed array of support cells that transfer the weight of material being contained to a surface on which the container is set over at least as many contact points as there are support cells positioned in the base frame. The support cells can be hollow or solid. The container assembly further comprises vertical walls that fully bound and support only the base frame, and vertical corner posts that support the walls and establish the height and level of the container.  
           [0007]    The walls of the container assembly can provide attachment points for the base frame and an auxiliary frame on either long vertical side. The corner posts can provide attachment points for walls on all vertical sides.  
           [0008]    The container assembly can also comprise a solid, rigid horizontal auxiliary frame positioned above the support cells. Additionally, passages within the auxiliary frame can be provided to allow flow within and through it.  
           [0009]    The support cells can include support sleeves that remove the load from specific support cells and transfer it directly from those load-bearing locations to the base frame. Both the support cells and the support sleeves can be provided with holes or openings in the respective bottom walls. The support cells can also be provided with a spherically or cylindrically contoured bottom wall and a correspondingly shaped foot closely fit to the contour of the bottom wall such that the rotating-foot has typically three primary points of contact with a load-bearing surface of any slope less than 45 degrees.  
           [0010]    The container assembly can also comprise openings to allow flow between an exterior top and an interior of the container.  
           [0011]    In yet another embodiment of the invention, a system for containing material comprises a first container assembly. The first container assembly includes a base frame having a plurality of guide holes and a plurality of support cells. Each support cell is disposed within one of the plurality of guide holes. Preferably the base frame is configured to so that the plurality of support cells form a closely packed array. The container assembly also comprises a plurality of container walls extending from the base frame.  
           [0012]    The first container system can also comprise a first corner post extending upward from proximate the base frame. The first corner post can be connected to a first container wall of the plurality of container walls and to a second container wall of the plurality of walls. A second corner post can extend upward from proximate the base frame, the second corner post connected to the second container wall of the plurality of walls and to a third container wall of the plurality of walls. Additional corner posts can be added to connect all of the container walls as needed. A leveling foot can be connected to and support one or more of the corner posts in a system.  
           [0013]    A variety of means can be used to connect the base frame to the container walls. For example, the walls can be connected by a fastener, a clamp, or a tongue and groove connection.  
           [0014]    The plurality of support cells can be configured to comprise a first upper segment and a second lower segment. The second lower segment can have a generally uniform cross-sectional area less than a generally uniform cross-sectional area of the first upper segment. The cross-sectional shape of the upper segment can match the shape of the base frame.  
           [0015]    In one form of the invention, the support cells can comprise a hollow interior and a open top. This form can also comprise a plurality of openings in a bottom wall or side wall. Alternatively, the support cell can be generally solid, and can include a plurality of holes running through the support cell. Moreover, the plurality of support cells can be constructed of a porous material.  
           [0016]    A modified support cell can be also be utilized. For example, one or more of the support cells can comprises a rotating foot connected to a bottom portion of the second lower segment of the support cell. Alternatively, one or more of the support cells can comprise a support sleeve positioned around the support cell. The support sleeve may include one or more holes or openings in a bottom wall of the support sleeve.  
           [0017]    The base frame can be configured in any number of shapes (as generally shown in a top plan view of the base). For example, the base frame can have a generally square shape, a generally rectangular shape, a generally triangular shape, a generally octagonal shape, a generally hexagonal shape, or a generally circular shape.  
           [0018]    The first container system can also comprise an auxiliary frame positioned above the plurality of support cells. The auxiliary frame can be connected to at least one or more of the plurality of container walls. The auxiliary frame can be in a variety of configurations. For example, the auxiliary frame can be in the form of a solid plate, a perforated plate, a grid, or a network of channels.  
           [0019]    The system can also comprise a second container assembly connected to the first container assembly. The second container assembly can be similar to the first container assembly and include a base frame having a plurality of guide holes, a plurality of support cells disposed in the guide holes, and a plurality of container walls wherein at least one of the plurality of container walls of the second container assembly is one of the plurality of container walls of the first container assembly. Additional container assemblies can be also be connected to the first container assembly, or to subsequently added container assemblies as desired.  
           [0020]    The base frame and other components of the system can be formed from a high density thermoplastic material, thermoset composite, metal, wood or a combination thereof.  
           [0021]    In yet another embodiment of the invention, a system for containing a material on a non-level surface comprises a first container assembly. The first container assembly includes a first base frame having a first array of guide holes, and a first plurality of support cells wherein each support cell is disposed in one of the first array of guide holes. The first container assembly also includes a first substantially vertical wall connected to a first side of the first base frame, a second substantially vertical wall connected to a second side of the first base frame and, a third substantially vertical wall connected to a third side of the first base frame. A fourth substantially vertical wall, or more, can be connected to additional sides of the base frame as necessary and as dictated by the shape of the base frame.  
           [0022]    The first container assembly can also include a first corner post connected to the first substantially vertical wall and the second substantially vertical wall, and a second corner post connected to the second substantially vertical wall and the third substantially vertical wall. Additional corner posts can be added as necessary to connect all of the walls in an assembly. One or more of the corner posts can include a leveling foot connected to and supporting the corner post.  
           [0023]    The first container assembly can include an auxiliary frame positioned above the array of support cells and connected to the first substantially vertical wall.  
           [0024]    The system can further include a second container assembly connected to the first container assembly. The second container assembly can include a second base frame having a second array of guide holes, a second plurality of support cells wherein each of the second plurality of support cells is disposed in one of the second array of guide holes, the first substantially vertical wall connected to a first side of the second base frame, a fourth substantially vertical wall connected to a second side of the second base frame and, a fifth substantially vertical wall connected to a third side of the second base frame. In this configuration, the first substantially vertical wall is common to both the first container assembly and the second container assembly. The first container wall can be configured to include means for connecting the wall to a base frame on both sides of the wall. The other walls can be similarly configured to expand the system as desired.  
           [0025]    In yet a further embodiment of the invention, a support cell for use with a container system for holding a fluid material comprises a first upper segment having a first cross-sectional area, a second lower segment having a second cross-sectional area, the second cross-sectional area being less than the first cross-sectional area. Preferably, the second cross-sectional area is slightly less than the cross-sectional area of a hole in a base frame. The support cell can be formed from a high density thermoplastic, thermoset composite, or a porous material.  
           [0026]    The support cell can be a substantially solid piece. Additionally, it may include one or more small openings that run through the support cell.  
           [0027]    Alternatively, the support cell can have a hollow interior and an open top. In this form, the support cell can also include one or more openings in a bottom wall or side wall of the lower segment.  
           [0028]    The support cell can also comprise a rotating foot connected to a bottom portion of the lower segment of the support cell. The rotating foot can have a generally spherical portion connected to a support surface.  
           [0029]    The support cell can also comprise a support sleeve positioned about an outer portion of the support cell. The sleeve can include one or more openings in a bottom wall or side wall of the support sleeve.  
           [0030]    Other systems, methods, features, and advantages of the present invention will be, or will become, apparent to one having ordinary skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0031]    The invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.  
         [0032]    [0032]FIG. 1 is a cross-sectional side diagrammatic view along one row of support cells of the present invention located on an unlevel surface;  
         [0033]    [0033]FIG. 2 is a partial perspective view of a support cell frame and several inserted support cells of the present invention;  
         [0034]    [0034]FIG. 3 is a top plan view of a square form of the present invention;  
         [0035]    [0035]FIG. 4 is a top plan view of a hexagonal form of the present invention;  
         [0036]    [0036]FIG. 5A is a cross-sectional view of an open form of a single support cell of the present invention;  
         [0037]    [0037]FIG. 5B is a cross-sectional view of an another open form of a single support cell of the present invention;  
         [0038]    [0038]FIG. 6 is a cross-sectional side diagrammatic view of a single support cell of the present invention in which the form of the support cell is hollow and has a rotating foot; and,  
         [0039]    [0039]FIG. 7 is a cross-sectional side diagrammatic view along a portion of a row of support cells of the present invention in a form which includes a support sleeve positioned around a single cell. 
     
    
     DETAILED DESCRIPTION  
       [0040]    While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspects of the invention to the embodiments illustrated.  
         [0041]    The present invention is a stationary container system in which the material being contained is fluid. The fluid may be, for example, soil, dirt, gravel or other materials for growing and irrigating vegetation.  
         [0042]    Referring to FIG. 1, a cross-sectional side diagrammatic view of the container  1  on an unlevel load-bearing surface  2  according to the present invention is shown. The base of the container  1  is formed by an array of closely-packed columnar support cells  3  that are able to move freely vertically through guide holes  4  in a horizontal base frame  5 . Each support cell  3  has a lower segment  6  of uniform cross-sectional area slightly less than the area of the guide hole and an upper segment  7  with a uniform cross-sectional area greater than that of the guide hole. The guide holes are spaced sufficiently apart so that the upper segment of one cell does not interfere with the upper segment of an adjacent cell.  
         [0043]    The base frame  5  is attached to a plurality of container walls  8  through the use of fasteners, clamps, or by means of a tapered tab captured in a groove with stops and possibly filled with spacers  9 . Each container wall  8  has vertical sides and is attached to and supported by a vertical corner post  10  (shown in FIG. 3) through the use of fasteners, clamps, or by means of a tapered tab captured in a groove with stops. Each corner post  10  is positioned vertically by means of a container leveling foot  11  that supports the corner post  10  as an unattached block of selected height or as a column partly contained within and attached to the corner post  10  through the use of set screws or a clamp.  
         [0044]    The container  1  might also have an auxiliary frame  12  positioned above the support cells  3  and attached to each wall  8  in a fashion similar to that of the base frame  5 . If the auxiliary frame  12  is attached to one of the walls  8  through a dovetail groove, it may be held in position by auxiliary frame stops  13  that are attached to each wall by fasteners, set screws or spacers  9  stacked between the frames. The auxiliary frame  12  can be, for example, a solid or perforated plate, a grid, a network of channels  14 , or a combination of any of these design characteristics.  
         [0045]    Referring to FIG. 2, a partial perspective view of the base frame  5  in another aspect of the present invention in which the container  1  is suspended so that no force is applied to the bottom of the support cells  3  is shown. Specifically, the base frame  5  is shown with five inserted support cells  3  and four additional guide holes  4  without support cells present. The five support cells  3  are shown to be supported by the bottom of the wider upper segment  7 .  
         [0046]    Referring to FIG. 3, a top plan view of a form of the present invention in which the basic shape is square  15  and an auxiliary frame  12  is not present is shown. All of the support cells  3  are shown to be closely packed within the confines of the container walls  8 . The base frame is attached to each container wall  8  by tapered tabs  16  captured in dovetail grooves  17  within each container wall  8  and each wall similarly captured within each container corner post  10 . A container wall  8  can be provided with dovetail grooves  18  on both of the long sides so that base frames can be attached to either side of it and thus perform as a common container wall  8  for two containers  1 . Likewise, a container corner post  10  might have attachment points  19  on all four vertical sides in order to perform as a common container corner post  10  for four containers.  
         [0047]    Referring to FIG. 4, a top plan view of another form of the present invention in which the basic shape is hexagonal  20  and an auxiliary frame is not present is shown. All of the hexagonal support cells  21  are shown to be closely packed within the confines of the container walls  22 . In the form of the invention shown in FIG. 4, the base frame is attached to each container wall  22  by tabs  50  captured within grooves  23  located at different angles along the container wall  22 . Each wall  22  is attached to each container corner post  52  by tapered tabs  54  captured in dovetail grooves within each container corner post  52 . A container wall  22  might have grooves  24  on both of the long sides so that base frames can be attached to either side of it and thus perform as a common container wall for two containers. Likewise, a container corner post might have attachment points  25  on all six vertical sides in order to perform as a common container corner post for six containers. While the square and hexagonal top-view shapes represent the best mode geometries, other top-view shapes for the present invention may also include but are not limited to rectangular, triangular, octagonal, and circular shapes.  
         [0048]    Referring to FIGS. 5A and 5B, yet another form of the present invention in which a cross-sectional isometric view of an open support cell  26  is shown. The open support cell  26  maintains the same outside geometry as the support cell  3  shown in FIGS. 1 through 3. The open support cell  26  lacks an enclosing top so that the top surface is defined by the edges of the support cell walls  27 . The open support cell  26  might also have small openings  28  through the bottom wall. The open support cell might also have small openings through one or more of the side walls. Another form of the open support cell (not shown) is a solid cell with holes running through the cell. Yet another form of the open support cell is similar to the support cell  3  shown in FIGS.  1 - 3  but constructed of a porous medium. The dimensions of the open support cell  26  are dictated by the structural and fluid control requirements of the application of the present invention.  
         [0049]    Referring to FIG. 6, yet another form of the present invention in which a cross-sectioned side diagrammatic view of an open support cell  29  with a rotating foot  31  is shown. The support cell  29  shown in FIG. 6 is similar to the open support cell with the exception of the support cell bottom wall having a spherical concave contour  30  in order to fit closely over the spherical upper portion of the support cell foot  31 . The contour of the bottom wall of the support cell  30  might have spherical dimensions such that the spherical upper portion of the support cell foot  31  is captured within the socket. The support cell foot  31  has a circular bottom surface that is in contact with the unlevel load-bearing surface  2  and has a diameter slightly smaller than the width of the support cell. Below the spherical section, the support cell foot  31  has conical or beveled sides that provide sufficient clearance below the support cell to allow a specified rotation angle ∝ around any horizontal axis. Typically, the rotation angle ∝ is less than 45 degrees. Another form of the rotating-foot support cell might be solid rather than of an open form. Yet, another form of the rotating-foot support cell might have a bottom wall with a convex spherical contour that fits closely into a concave socket at the top of the support cell foot. Yet another form of the rotating-foot support cell might have a foot that rotates about or within a cylinder rather than a sphere, limiting the freedom of rotation to a single horizontal axis. A foot with a cylindrical upper section might have a rectangular-shaped bottom surface.  
         [0050]    Referring to FIG. 7, yet another form of the present invention is shown in which a cross-sectional side diagrammatic view along a portion of a row of support cells of the present invention includes a support sleeve  32  positioned around a single support cell  26 . The support sleeve  32  fits closely around a support cell and is in contact with the base frame  5  while having no contact with the bottom of the support cell. As shown in FIG. 7, the support sleeve  32  might also have openings  33  near or at the bottom to allow flow between the inside and the outside of the support sleeve  32 .  
         [0051]    The overall dimensions of the container  1  in all its forms are generally unlimited, however, those practiced in the art will appreciate that specific dimensions are dictated by a particular application. Likewise, the maximum number of support cells  3  is generally unlimited but specifically limited by a particular application. The minimum number of support cells  3  is generally equal to the number of container walls  8  but, again, specifically limited by a particular application. The maximum total height of a support cell  3  is less than the container wall  8  height. The minimum height of the lower cell segment  6  is greater than the thickness of the base frame  5  while the minimum height of the upper cell segment  7  is sufficiently great enough to prevent the possibility of a vertical gap existing between two adjacent support cells  3  as dictated by a particular application, e.g. a surface with large protrusions. The dimensions of the base frame  5  are limited by the container  1  interior cross-section horizontally and the height of the container walls  8  vertically. The width of a corner post is generally equal to the thickness of a container wall in order to accommodate the creation of multiple containers with a common corner post. The dimensions of the auxiliary frame  12  are generally limited to the interior dimensions of the container  1  but are specifically dictated by the particular application.  
         [0052]    Each of the components of the present invention can be constructed of a wide range of solid materials including but not limited to high density thermoplastics, thermoset composites, various metals, rigid porous media, or wood. Those practiced in the art will appreciate that each of the components described can be formed through a variety of techniques including but not limited to injection molding, casting, or milling as dictated by the specific application.  
         [0053]    Applicability  
         [0054]    Since the material within the container  1  is typically a static fluid, the loads applied to the interior surfaces of the container  1  are force vectors normal to the interior surfaces of the container walls  8  and support cells  3 . Each force vector has a vertical component and a horizontal component but only the vertical component is equally opposed by the solid load-bearing surface  2 . Referring to FIG. 1, a force vector  34  applied to the vertical interior surface of a container wall  8  has a vertical force component equal to zero, thus the entire weight, or vertical force due to gravity  35 , of the fluid is applied to the support cells  3 . The advantages of the present invention are maximized when each of the support cells  3  in the container  1  has equal and opposite net vertical forces applied to it by the fluid and the solid load-bearing surface  2  exclusively. In this state, the weight of the fluid is transferred through the bottom of the container  1  at as many points as there are support cells  3 . It should be appreciated that applications might exist in which extreme unevenness of the load-bearing surface  2  prohibits one or more support cells  3  from being in contact with the load surface  2 , therefore, the system is considered optimized when the distances between the base frame  5  and the load-bearing surface  2  is such that a minimum number of support cells  3  have contact with the top horizontal surface of the base frame  5  and the base frame  5  has minimal or no contact with the load-bearing surface  2 . The distances between the base frame  5  and the load bearing surface  2  are established by the vertical adjustment of the container leveling feet. Typically, the container is applied to load-bearing surfaces with a slope of less than 45 degrees.  
         [0055]    Depending on the form that it takes and the manner in which it is applied, the auxiliary frame serves many functions. For example, one form of the auxiliary frame is a dense grid-like network of conduits  14  that provides horizontal support to the container walls  8  in addition to the base frame  5 , controls the displacement of material in the container  1  by limiting the flow or movement of material vertically at the surface, provides a solid surface for any additional loads applied to the top of the container  1 , and serves as a means to flow water or other liquids or gases into or out of the container  1 . Another possible form of the auxiliary frame is a solid, rigid load-bearing plate that is allowed to float on the contained fluid and is of sufficient thickness at the tapered frame tab  16  to be held horizontal by the container walls  8 .  
         [0056]    Referring to FIGS. 3 and 4, a container wall might have grooves on both of the long sides so that base frames can be attached to either side of it and thus perform as a common container wall for two containers. Likewise, a container corner post might have attachment points on all vertical sides in order to perform as a common container corner post for multiple containers. In this way, multiple containers might be assembled adjacently so that a large surface could be covered by an array of interconnected containers with less weight and cost than an array of individually constructed and installed containers.  
         [0057]    Referring to FIGS. 5A and 5B, the open support cell  26  lacks an enclosing top so that the top surface is defined by the edges of the support cell walls  27 , thus providing greater volume for the container  1  than the form of the present invention using a fully enclosed or solid support cell  3 . The open support cell  26  might also have small openings  28  in the bottom (or sides) to allow for drainage or other flow between the inside and outside of the container  1 . Another form of the open support cell is a solid cell with holes running through the cell to allow flow between the inside and outside of the container  1 .  
         [0058]    Referring to FIG. 6, the rotating-foot support cell  29  typically allows three primary contact points between a single support cell and the load-bearing surface  2 . A support cell without a foot typically has only one or two primary contact points with the load-bearing surface  2 .  
         [0059]    Referring to FIG. 7, all of the load-bearing force  36  applied to the bottom of the support sleeve transfers directly to the base frame  5 . Typically, the support cells in the vicinity of a support sleeve will rest on the base frame  5  so that the container load forces due to gravity in the vicinity of the sleeve-supported cell will translate to the load-bearing surface through the support sleeve  32 . Support sleeves might be positioned over various support cells in order to allow the container load to be concentrated at specified points on the load-bearing surface for special applications such as when a container must be positioned over an especially large depression or a particularly weak area of a roof or balcony.  
         [0060]    While the present invention could be used as a container on any surface, the advantages of the invention are realized where the surface is uneven, sloped, or has limited load pressure capabilities. Such surfaces on which the present invention might be beneficially applied include, but are not limited to building rooftops, balconies, terraces, sloped floors, unstable ground, or extremely uneven ground or rock. Specific examples of applications of the present invention include vegetation containers located on building rooftops or balconies, storage containers for fluid material located on rooftops or sloped floors, containers filled with very low density granular fluid material and covered with a solid auxiliary frames to serve as platforms or walkways on rooftops or unstable ground, or containers for loose construction foundation material located on extremely uneven or unstable ground.  
         [0061]    It should be emphasized that the above-described embodiments of the present invention, particularly, any “preferred” embodiments, are merely possible examples of implementations, merely setting forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiment(s) of the invention without substantially departing from the spirit and principles of the invention. All such modifications are intended to be included herein within the scope of this disclosure and the present invention and protected by the following claims.