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 supports sleeve surrounds the at least one support member and is encased within the slab foundation and is capable of movement axially along the length 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. 61/224,785, filed on Jul. 10, 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 length 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. 
     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 substantially cylindrical 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. A support plate is connected to the second end of the at least one substantially vertical support member. The support plate has an aperture located in and extending therethrough and a plurality of tabs extending radially outward from the outer peripheries of the support plate at select intervals. 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. 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 plurality of tabs of the at least one support sleeve are initially offset from the plurality of tabs of the support plate. 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 length of the at least one support member. The at least one support member and the support plate are capable of rotation relative to the at least one support sleeve to align the plurality of tabs of the support plate with the plurality of tabs of 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 extends through the aperture in the support plate and 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. A plurality of support members 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 length 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 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 lifting rod inserted and a lifting assembly connected. 
         FIG. 4  is a sectional view of the support sleeve, support pipe, and support plate taken along the line  4 - 4  of  FIG. 3 . 
         FIG. 5  is a sectional view of the single slab support with the slab raised. 
         FIG. 6  is a sectional view of the support sleeve, support pipe, and support plate taken along the line  6 - 6  of  FIG. 5 . 
         FIG. 7  is a sectional view of a single slab support with the slab raised to a final height. 
     
    
    
     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 pate  15  is circular in shape, but in alternate embodiments may comprise different shapes, for example, a rectangle. In an alternate embodiment, the base plate  15  may have anchor bolts or other support members connected to it that extend a selected distance into the pier  13 . 
     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 an alternate embodiment, anchor bolts or other support members may be connected to the base plate  15  and may extend into the concrete of the pier  13  a desired distance below the base plate  15 . 
     In this embodiment, a cylindrical exterior pipe or support sleeve  19  has an outer diameter that is less than the diameter of the base plate  15 . The support sleeve  19  and the base plate  15  are sized such that 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 tab  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 ninety degree 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 particular embodiment, two lift holes  33  are positioned opposite from one another and are offset from the support tabs  23 . The lift holes  33  are adapted 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  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 slab  11  has hardened, a support member or support pipe  35  with a smaller diameter than the sleeve  19  is inserted into the sleeve  19  and lowered until a lower first end portion makes contact with the base plate  15 . The support pipe  35  is positioned such that the first end portion of the support pipe  35  rests on the base plate  15 . A support flange or support plate  37  is connected to an upper second end portion of the support pipe  35 . The support pipe  35  extends upwardly a select distance from the base plate  15 . The length of the supporting pipe  35 , and subsequently, the height of the support plate  37  can be varied to accommodate various desired slab  11  heights. 
     As illustrated in  FIG. 4 , the support plate  37  has a hole or aperture  39  located in and extending axially therethrough that is adapted to receive a lifting member. The outer peripheries of the support plate  37  are designed with a plurality of tabs  41  that have a greater diameter than the rest of plate  37 . In this embodiment, the tabs  41  are positioned opposite one another and extend around the plate  37  at intervals of less than ninety degrees. The desired final height of the slab  11  is determined by the height of the plate  37  and the plate tabs  41  relative to the base plate  15 . In an alternate embodiment, the plate  37  may be threaded to the second end of the support pipe  35 , thereby allowing the vertical position and height of the plate  37 , the tabs  41 , and the corresponding final height of the slab  11  to be adjusted. 
     Referring back to  FIG. 3 , a lifting member or solid lifting rod  43  with a smaller diameter than the aperture  39  in the support plate  37  is inserted into the aperture  39  and the support pipe  35  and lowered until it makes contact with the base plate  15 . The length of the lifting rod  43  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  43  may be removed from the support pipe  35  once the slab  11  has reached its desired height. After the lifting rod  43  is in place, a lifting device  45  is mounted on the top of the support rod  43 . In this embodiment, the lifting device  45  is a hydraulic jack mounted on the top of the support rod  43 . 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. The hydraulic jack  45  is connected to the attachment rods  47 . In order to lift the sleeve  19  and the slab foundation  11 , the support pipe  35  is rotated such that tabs  41  on the support plate  37  and the support tabs  23  on the inner surface  21  of the support sleeve  19  are offset from one another, thereby allowing the sleeve  19  and the tabs  23  to pass by the plate  37  and the tabs  41  without interference ( FIG. 4 ). 
     Referring to  FIG. 5 , hydraulic fluid pressure is applied to the jack  45 , causing the foundation slab  11  to be lifted above the ground to the desired height. Once the slab  11  has reached its desired height, the tabs  23  on the inner surface  21  of the sleeve  19  will be positioned above the plate  37  and the tabs  41 . In order to secure the slab  11  at the desired height, the support pipe  35  and the plate  37  are rotated such that plate tabs  41  and the support tabs  23  are aligned with one another ( FIG. 6 ). Once the support tabs  23  are positioned above the plate tabs  41 , the sleeve  19  and the slab foundation  11  are lowered such that tabs  23  of the sleeve  19  rest upon the tabs  41  on the plate  37 . Once the tabs  23  of the support sleeve  19  are securely resting upon the tabs  41  of the plate  37 , the attachment rods  47 , the hydraulic jack  45 , and the lifting rod  43  are removed. 
     Referring to  FIG. 7 , the lifting rod  43  ( FIG. 5 ) may be removed if its length is greater than the final height of the slab  11 . Whether the lifting rod  43  is removed or remains within the support pipe  35 , once the slab  11  has reach its desire height, a cap  49  can be inserted into the sleeve  19 . In the event that the height of the slab  11  needs to be adjusted, the cap  49  may be removed, the lifting rod  43  reinserted if not already in place, and the hydraulic jack  45  and the attachment rods  47  reconnected. Once the weight of the slab  11  is lifted from the support pipe  19 , if the plate  37  is threaded to the support pipe  35 , the height could be adjusted by rotating the plate  37  to a desired height. If the plate  37  is not threaded to the support pipe  35 , the slab  11  is lowered to its original position, and the support pipe  35  and the plate  37  may be replaced with a supporting pipe and a plate with a length to accommodate the new desired height. Once the desired height is reached, as previously illustrated, the slab  11  may be secured in place by rotating the new support pipe and plate and lowering the weight of the slab  11  and the sleeve  19  onto the new support pipe and plate. As previously discussed, the hydraulic jack  45 , the attachment rods  47 , and the lifting rod  43  may 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.