Abstract:
An embodiment of the system for forming a movable slab foundation as comprised by the present invention has a slab foundation, at least one substantially vertical support member, at least one support surface, and at least one support sleeve. The at least one support sleeve surrounds the at least one support member and is encased within the slab foundation and is capable of movement axially along the axis of the at least one support member. The at least one vertical support member is capable of rotation relative to the at least one support sleeve to restrict the movement of the at least one support sleeve downward relative to the at least one vertical support member, thereby maintaining the height of the at least one support sleeve and the slab foundation relative to the at least one support surface.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of and priority to U.S. Provisional Patent Application No. 61/229,154, filed on Jul. 28, 2009, and herein incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention relates in general to forming an adjustable foundation, and in particular, to a concrete slab foundation capable of being raised above the ground. 
     BACKGROUND OF THE INVENTION 
     Many structures have been built on foundations or slabs made of concrete poured on top of soil. Constant changes in the weather and moisture levels in the soil frequently cause damage to such a foundation. In many instances, the foundation may buckle or even crack. This phenomenon occurs for a variety of reasons, including uneven changes in the water content of supporting soils, uneven compacting of soils, and uneven loads being placed on soils. Over time, uneven movement in the soils under a foundation can cause a foundation to bend or crack. 
     Therefore, it would be desirable to provide a method and apparatus that would allow a foundation to be poured on top of soil and subsequently raised to a desired height to eliminate potential problems caused by soil movement and/or problematic soils. 
     SUMMARY OF THE INVENTION 
     An embodiment of the system for forming a movable slab foundation as comprised by the present invention has a slab foundation. At least one substantially vertical support member has a hollow body with first and second ends. The first end of the substantially vertical support member is in abutting contact with at least one support surface. At least one support sleeve surrounds the at least one support member. The at least one support sleeve is encased within the slab foundation and is capable of movement axially along the axis of the at least one support member. The at least one support sleeve has an opening through which the at least one support member extends. The opening is substantially geometrically complimentary to the at least one support member. The at least one vertical support member is capable of rotation relative to the at least one support sleeve to restrict the movement of the at least one support sleeve downward relative to the at least one vertical support member, thereby maintaining the height of the at least one support sleeve and the slab foundation relative to the at least one support surface. 
     An embodiment of the system for forming a movable slab foundation as comprised by the present invention has a slab foundation. At least one substantially vertical support member has a generally elliptical shaped hollow body with first and second ends. The first end of the at least one support member is in abutting contacting with at least one support surface. At least one support sleeve has a hollow body with inner and outer surfaces. The at least one support sleeve surrounds the at least one support member. The inner surface of the at least one support sleeve has a plurality of tabs extending along and radially inward from the inner surface at select intervals to thereby define a generally elliptical shaped opening. The opening is substantially geometrically complimentary to the at least one support member. The inner surface of the at least one support sleeve also has a plurality of apertures located in and extending therethrough. The outer surface of the at least one support sleeve has at least one reinforcing bar connected to and extending outwardly therefrom. The at least one support member initially extends through the substantially geometrically complimentary opening in the at least one support sleeve. The outer surface of the sleeve body and the at least one reinforcing bar are encased within the slab foundation. The at least one support sleeve and the slab foundation are capable of movement axially along the axis of the at least one support member. The at least one support member is capable of rotation relative to the at least one support sleeve to offset the at least one support member from the opening in the at least one support sleeve to thereby restrict the movement of the at least one support sleeve downward relative to the at least one support member. At least one lifting member is surrounded by the at least one support member. The at least one lifting member has a body with first and second ends, the first end being in abutting contact with the at least one support surface. 
     An embodiment of the present invention is directed to a method for forming a movable slab foundation. The method comprises placing a plurality of support surfaces below an intended slab foundation area. A plurality of support sleeves are placed in abutting contact with the plurality of support surfaces. The plurality of support sleeves have a geometrically shaped opening extending axially therethrough. A plurality of support members being geometrically complimentary to the openings are inserted into the openings and are placed within the plurality of support sleeves. The plurality of support members are slid down within the plurality of support sleeves and into abutting contact with the plurality of support surfaces. A slab foundation is formed such that it encases the plurality of support sleeves. The plurality of support sleeves are simultaneously lifted to move the slab foundation along the axes of the plurality of support members to a desired height. The plurality of support members are rotated relative to the plurality of support sleeves, thereby restricting the movement of the plurality of support sleeves downward relative to the plurality of support members and maintaining the desired height of the slab foundation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the features and benefits of the invention, as well as others which will become apparent, may be understood in more detail, a more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof which are illustrated in the appended drawings, which form a part of this specification. It is also to be noted, however, that the drawings illustrate only various embodiments of the invention and are therefore not to be considered limiting of the invention&#39;s scope as it may include other effective embodiments as well. 
         FIG. 1  is a sectional view of a single slab support, illustrating a concrete pier and a support sleeve. 
         FIG. 2  is a sectional view of the support sleeve taken along the line  2 - 2  of  FIG. 1 . 
         FIG. 3  is a sectional view of the single slab support with a support pipe and a lifting rod inserted and a lifting assembly connected. 
         FIG. 4  is a sectional view of the support sleeve and the support pipe taken along the line  4 - 4  of  FIG. 3 . 
         FIG. 5  is a sectional view of the single slab support with the slab raised a distance above a ground surface. 
         FIG. 6  is a sectional view of the single slab support with the slab raised to a final height. 
         FIG. 7  is a sectional view of the support sleeve and support pipe taken along the line  7 - 7  of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention now will be described more fully hereinafter with reference to the accompanying drawings in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein; rather, this embodiment is provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. 
     Referring to  FIG. 1 , a foundation slab  11  may be used to support a house or other building or structure. In this embodiment, the slab  11  is of concrete and initially rests on a ground surface  17  and a support surface or pier  13 . The foundation or slab  11  is typically supported by a plurality of support surfaces or piers  13 , but for simplification purposes, the single pier  13  will be discussed. In this embodiment, the pier  13  is of concrete and has a base plate  15  embedded therein, such that at least the top or upper surface of the base plate  15  is exposed. In this embodiment, the base plate  15  is circular in shape, but in alternate embodiments may comprise different shapes, for example, a rectangle. In this embodiment, the base plate  15  has an anchor bolt  16  connected to it that extends a select distance into the concrete pier  13 . In alternate embodiments, other support members may be connected to the base plate  15 . 
     In this embodiment, the hole for the pier  13  is dug with a diameter such that the base plate  15  is fully encased within the concrete. Once the hole is dug as desired, the pier  13  is formed by pouring concrete into the hole. The base plate  15  is then embedded in the concrete of the pier  13  such that the top or upper surface of the base plate  15  is substantially parallel with the ground surface  17 . As previously discussed, in this embodiment, the anchor bolt  16  is connected to the base plate  15  and extends into the concrete of the pier  13  a distance below base the plate  15 . 
     In this embodiment, a cylindrical exterior pipe or support sleeve  19  has an outer diameter less than the diameter of the base plate  15 . The support sleeve  19  and the base plate  15  are sized such that the bottom surface of the support sleeve  19  is in supporting contact with the base plate  15 . The length of the support sleeve  19  may be less than or equal to the desired thickness of the concrete slab  11 . In this embodiment, the length of the support sleeve  19  is equal to the thickness of the concrete slab  11 . An inner surface  21  of the sleeve  19  has a plurality of support tabs  23  connected therein that extend along the inner diameter and radially inward a select distance. The support tabs  23  may be connected to the support sleeve  19  through various means, including, but not limited to welding and fasteners. As seen in  FIG. 2 , in this embodiment, two support tabs  23  are positioned opposite from one another and extend around the inner surface  21  of the support sleeve  19  at select intervals. 
     Referring back to  FIG. 1 , reinforcing bars (rebar)  25  are connected to the outer surface of the sleeve  19 . In this embodiment, a first leg  27  of the rebar  25  is connected to and extends outwardly and downwardly at an angle from the sleeve  19 . A second leg  29  of the rebar  25  is substantially perpendicular to the support sleeve  19  and extends between the first leg  27  and the sleeve  19 . The rebar  25  may be welded around the outer peripheries of the sleeve  19  at desired intervals. In an alternate embodiment, various reinforcing members may be connected to and extend outwardly from the outer peripheries of the sleeve  19  in various shapes and configurations. 
     A plurality of lift holes or apertures  33  are located in and extend radially outward through the inner surface  21  of the support sleeve  19 . In this embodiment, two lift holes  33  are positioned opposite from one another. The lift holes  33  are designed to accept a lifting device or lifting link. 
     The sleeve assembly  19  is positioned atop the base plate  15 . In an alternate embodiment, the lower end of the support sleeve  19  may be lightly tack welded to the base plate  15 . The concrete slab  11  is then poured, thereby embedding the rebar  25  and the sleeve assembly  19  within the slab  11 . The concrete may be kept from bonding to the concrete pier  13  and the base plate  15  by an optional bond breaker layer (not shown). 
     Referring to  FIG. 3 , after the cement slab  11  has hardened, a support member or support pipe  35  having an elliptical shape ( FIG. 4 ) is inserted into the sleeve  19  and lowered until a lower first end portion makes contact with the base plate  15 . The elliptical shape of the support pipe  35  requires that it be properly oriented with respect to the support sleeve  19  to allow the support pipe  35  to pass by the tabs  23  on the inner surface  21  of the sleeve  19  without interference ( FIG. 4 ). The support pipe  35  is positioned such that the lower first end portion of the support pipe  35  rests on the base plate  15 . The support pipe  35  extends upwardly a selected distance from the base plate  15 . The length of supporting pipe  35  can be varied to accommodate various desired slab  11  heights. As shown in  FIG. 4 , the support pipe  35  is elliptical in shape and is adapted to receive a lift bar  37 . The desired final height of the slab  11  is determined by the length of the support pipe  35 . 
     Referring back to  FIG. 3 , a lifting member or solid lifting rod  37 , with a smaller diameter than the support pipe  35  is inserted into the support pipe  35  and lowered until it makes contact with the base plate  15 . The length of the lifting rod  37  can be calculated such that it may remain within the support pipe  35  once the slab  11  has reached its final desired height. Alternatively, the lifting rod  37  may be removed from the support pipe  35  once the slab  11  has reached its final desired height. After the lifting rod  37  is in place, a lift support plate  38  is positioned on the top of the support rod  43 . The support plate  38  has a plurality of apertures  39  located in and extending therethrough. A lifting device  41  is then mounted on the top of the support plate  38 . In this embodiment, the lifting device  41  is a hydraulic jack mounted on the top of the support plate  38 . A lift plate  43  is then positioned on top of the hydraulic jack  41 . The lift plate  43  has a plurality of apertures  45  located in and extending therethrough. The lift plate  43  is positioned such that the apertures  45  are in alignment with the apertures  39  in the support plate  38 . 
     Attachment members or attachment rods  47  are connected to the lift holes  33  in the sleeve  19  in order to lift the slab  11  to its desired height. In this embodiment, the attachment rods  47  contain threads in at least an upper portion thereof. The attachment rods  47  pass through the apertures  39  in the support plate  38  and the apertures  45  in the lift plate  43 . Nuts  48  are threaded onto upper portions of the attachment rods  47  located between the support plate  38  and the lift plate  43 . The nuts  48  may be adjusted once the slab  11  has been lifted to permit removal of the hydraulic jack  41 . Nuts  49  are threaded onto upper portions of the attachment rods  47 , above the lift plate  43 . The nuts  49  prevent the lift plate  43  from moving upward independently from the attachment rods  47  when the hydraulic jack  41  is activated. 
     Referring to  FIG. 5 , hydraulic fluid pressure is applied to the jack  41 , causing the jack  41  to push the lift plate  43  and the attachment rods  47  upwards relative to the base plate  15 . The jack  41  moves the lift plate  43  and the attachment rods  47  upwards until the foundation slab  11  has been lifted above the ground  17  to the desired height. In the event that the hydraulic jack  41  needs to be removed during the lifting process, the nuts  48  can be tightened against the support plate  38 , thereby allowing the lifting device  41  and the lift plate  43  to be removed if necessary, while maintaining the height of the slab  11 . 
     Referring to  FIG. 6 , once the slab  11  has reached its desired final height, the tabs  23  on the inner surface  21  of the sleeve  19  will be positioned above the support pipe  35 . In order to secure the slab  11  at the desired height, the support pipe  35  is then rotated such that the support tabs  23  are no longer offset from the elliptical shape of the support pipe  35  ( FIG. 7 ). Once the support tabs  23  are positioned above the support pipe  35 , and the support pipe  35  has been rotated to the proper position, the sleeve  19 , the slab foundation  11 , and the tabs  23  are lowered such that tabs  23  rest upon the support pipe  35 . Once the tabs  23  are securely resting upon the support pipe  35 , the attachment rods  47 , the support plate  38 , the hydraulic jack  41 , the lift plate  43 , and the lifting rod  37  ( FIG. 5 ) are removed. 
     Referring to  FIG. 6 , the lifting rod  37  ( FIG. 5 ) may be removed if its length is greater than the final height of the slab  11 . Whether the lifting rod  37  is removed or remains within the support pipe  35 , once the slab  11  has reach its desired height, a cap  49  can be inserted into the sleeve  19 . In the event that the height of slab  11  needs to be adjusted, the cap  49  may be removed, the lifting rod  37  reinserted if not already in place, and the support plate  38 , the hydraulic jack  41 , the lift plate  43 , and the attachment rods  47  reconnected. Once the weight of the slab  11  is lifted from the support pipe  35 , the support pipe  35  is rotated such that the tabs  23  on the inner surface  21  of the sleeve  19  will not interfere with the support pipe  35 . The slab  11  is lowered to its original position. The support pipe  35  may be replaced with a supporting pipe with a length to accommodate the new desired height. Once the desired height has been reached, as previously illustrated, the slab  11  may be secured in place by rotating the new support pipe and lowering the weight of the slab  11  and the sleeve  19  onto the new support pipe. As previously discussed, the hydraulic jack  41 , the support plate  38 , the lift plate  43 , the attachment rods  47 , and the lifting rod  37  may then be removed and the cap  49  reinstalled in the sleeve  19 . 
     The invention has significant advantages. The invention provides a method and apparatus that allows a foundation to be poured on top of soil and subsequently raised to a desired height to eliminate potential problems caused by soil movement and/or problematic soils. 
     In the drawings and specification, there have been disclosed a typical preferred embodiment of the invention, and although specific terms are employed, the terms are used in a descriptive sense only and not for purposes of limitation. The invention has been described in considerable detail with specific reference to these illustrated embodiments. It will be apparent, however, that various modifications and changes can be made within the spirit and scope of the invention as described in the foregoing specification and as set forth in the following claims.