Patent Publication Number: US-2011052329-A1

Title: System for Forming a Movable Slab Foundation

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of and priority to U.S. Provisional Patent Application No. 61/238,291, filed on Aug. 31, 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 and at least one support pier. At least one housing is positioned within the at least one support pier. The at least one housing has a closed upper end and an open lower end. A seal plate is positioned within and surrounded by the at least one housing. The outer peripheries of the seal plate sealingly engage the inner surfaces of the at least one housing. The at least one housing is upwardly moveable within the support pier relative to the seal plate. A cavity is defined by the space between the upper surface of the seal plate and the upper end of the at least one housing. A port is located in and extends through the closed upper end of the at least one housing and into the cavity. At least one support sleeve is encased within the slab foundation. The bottom surface of the at least one support sleeve abuttingly contacts the upper end of the at least one housing. 
     An embodiment of the system for forming a movable slab foundation as comprised by the present invention has a slab foundation and at least one support pier. At least one housing is positioned within the at least one support pier. The at least one housing has a closed upper end and an open lower end. A seal plate is positioned within and surrounded by the at least one housing. The outer peripheries of the seal plate sealingly engage the inner surfaces of the at least one housing. The at least one housing is upwardly moveable within the support pier relative to the seal plate. A cavity is defined by the space between the upper surface of the seal plate and the upper end of the at least one housing. A port is located in and extends through the closed upper end of the at least one housing and into the cavity. At least one support sleeve is encased within the slab foundation. The bottom surface of the at least one support sleeve abuttingly contacts the closed upper end of the at least one housing. A pumping device is connected to the port for pumping a support media into the cavity to thereby expand the cavity and move the housing, the support sleeve, and the slab foundation upwards relative to the seal plate. 
     An embodiment of the present invention is directed to a method for forming a movable slab foundation. The method comprises providing a housing with a closed upper end and an open lower end. A seal plate is positioned within and surrounded by the housing. The outer peripheries of the seal plate are sealingly engaged with the inner surfaces of the housing. A cavity is defined by the space between the upper end of the housing and the upper surface of the seal plate. A port located in and extends through the closed upper end of the housing and into the cavity. A support pier is placed below an intended slab foundation area. The inner and outer surfaces of the housing are treated with a form releaser. The housing and the seal plate are positioned within the support pier. A support sleeve is placed in abutting contact with the closed upper end of the housing. A slab foundation is formed such that it encases the support sleeve. A support media is pumped through the port and into the cavity, thereby expanding the cavity and simultaneously lifting the housing and the support sleeve to move the slab foundation upward relative to the seal plate to a desired height. 
    
    
     
       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, housing, seal plate, and concrete slab. 
         FIG. 2  is a sectional view of the single slab support with the housing and the slab raised to a desired 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. In this embodiment, the slab  11  is of concrete and initially rests on a ground surface  12  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 lifting assembly  15  embedded therein. The lifting assembly  15  consists of a liner  17  (optional), a housing  19 , and a seal plate  21 . In this embodiment, the housing  19  is a capped cylinder and the seal plate  21  is circular in shape. The seal plate  21  rides within the interior of the cylinder  19  and is sealingly engaged with an inner surface  23  of the cylinder  19  by an O-ring  25 , which rides in a slot around the outer surface of the seal plate  21 . A plurality of vent tubes  27  are located in and extend through the seal plate  21  before extending upward a select distance. A void  29  is initially present between the upper surface of the seal plate  21  and the closed end of the cylinder  19 . A plurality of apertures  31  are located in and extend through the closed end of the cylinder  19 . The apertures  31  are aligned with the vent tubes  27  and are adapted to accept the vent tubes  27  therein. An injection tube  33  is connected to a port  35  that is located in and extends through the closed end of the cylinder  19 . The injection tube  33  may be built as an integral part of the cylinder  19  or may be threaded thereon. In this embodiment, the injection tube  33  is formed as an integral part of the cylinder  19 . 
     The hole for the pier  13  is dug with a diameter such that the lifting assembly  15  is fully encased within the concrete. Once the hole is dug, the pier  13  is formed by pouring concrete into the hole. The lifting assembly  15  is then inserted into the concrete and pushed downward until the top surface of the cylinder  19  is substantially flush with the ground surface  12 . As previously discussed, the liner  17  surrounding the cylinder  19  may be simultaneously inserted into the pier  13 . Alternatively, the outer surface of cylinder  19  may be coated with a lubricant or form releaser. The inner surface  23  of the cylinder  19  is coated with a lubricant or form releaser to prevent the concrete of the pier  13  from bonding to the cylinder  19 . As the lifting assembly  15  is lowered into the concrete pier  13 , the air trapped within the cylinder  19  escapes through the vent tubes  27  and the apertures  31 . Once the concrete pier  13  has solidified, the seal plate  21  will be securely encased within the pier  13 . 
     In this embodiment, a hollow pipe or support sleeve  39  has a diameter that is less than the diameter of the cylinder  19 . In an alternate embodiment, various reinforcing members may be connected to and extend outwardly from the outer peripheries of the support sleeve  39  in various shapes and configurations. 
     The support sleeve  39  is placed on top of the closed end of cylinder  19  such that it surrounds the port  35  and the injection tube  33  (if attached). The diameter of the support sleeve  39  is such that the apertures  31  in the seal plate  21  are positioned radially outward from the port  35  a greater distance than the walls of the support sleeve  39 . The concrete may be kept from bonding to the concrete pier  13  and the liner  17  by a bond breaker layer (not shown) which is optional. 
     Referring to  FIG. 2 , after the slab  11  and the pier  13  have hardened, the injection tube  33 , if not already connected to the port  35 , is connected to the cylinder  19 . After the injection tube  33  is connected to the port  35 , a pumping device  41  is then connected to the injection tube  33  by a connecting link  43 . In this embodiment, the pumping device  41  is a concrete pump. Concrete or grout is then pumped by the concrete pump  41  into the link  43 , through the injection tube  33 , the port  35 , and into the void  29  ( FIG. 1 ) between the closed end of cylinder  19  and the seal plate  21 . As grout or concrete fills the space between the cylinder  19  and the seal plate  21 , the cylinder  19  acts as a piston as the concrete forces the cylinder  19  upwards relative to the ground surface  12 . The O-ring  25  maintains sealing contact between the seal plate  21  and the inner surface  23  of the cylinder  19 . The bottom surface of the concrete slab  11  abuts against the apertures  31 , thereby preventing the concrete or grout from exiting the cylinder  19  through the aperture  31 . The concrete or grout is pumped into the cylinder  19  until the foundation slab  11  is lifted above the ground to the desired height. Once the slab  11  has reached its desired height, the injection tube  33  may be crimped or sealed and the grout or concrete within the cylinder  19  is permitted to harden and set up. The connecting link  43  and the concrete pump  41  may be disconnected and removed. Once the concrete or grout has set up, the new positions of the cylinder  19  and the slab  11  are securely fixed at the desired heights. 
     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