Abstract: A system for leveling a slab by raising and filling in voids under the slab. A mixture of compressed air and well dried sand is pumped through hose to a gun nozzle. The slab to be leveled is supplied with at least one hole for receiving the gun nozzle in a fluid tight connection. The compressed air is used to lift the slab while the sand is used to fill the void and keep the slab in a level position. The operator may supply successive burst of pressure to lift the slab as needed, while adjusting the air and sand flow. Finally, the gun nozzle is removed from the hole which is then patched thus, completing the repair of the damaged slab.

Abstract: A method of raising a slab is described here that uses inflatable hoses to raise slabs needing to be raised, for example, to raise sunken slabs of a roadway to align to their adjacent slabs without closing the roadway and breaking ongoing traffic. The described method of raising a slab makes it more efficient to repair slabs needing to be raised while conventional repairing methods, for example, re-pouring, or mud jacking, which need to close the roadway and interrupt ongoing traffic, are more expensive, time consuming and less effective.

Abstract: A concrete slab leveling apparatus is provided that is built upon a vehicle such as a flatbed truck or trailer which makes it highly transportable enabling the invention to move from site to site quickly and easily. The flatbed platform of the vehicle is equipped with a material bin which is a relatively large opened topped box which holds the material that is to be pumped under a settled concrete slab. The material bin is also fitted with an auger that extends the length of the lower surface and is a screw-like device which is rotationally driven to move the material contained within the bin towards the front of the auger channel during operations so that it can be moved efficiently into the pump assembly. The present invention is also equipped with a hydraulic pump assembly which drives the fill material from the material bin and through a hose to the proper location under a concrete slab.

Abstract: A method of repairing concrete slabs that have become uneven and dangerous is provided that employs lime sludge that is injected under pressure into the space between the lower surface of the damaged concrete slab and the underlying ground to raise that slab back into a level orientation. Once this has been accomplished, any remaining space below the slab is filled in with well dried sand blown in under pressure.

Abstract: The present application discloses a sidewalk lifting device made of steel framed tower that has a flat plate extending inward from the lowest end of the tower. This plate holds the lower surface of a sidewalk slab and also provides the lifting surface to elevate a damaged sidewalk. Additionally, attached to the inside surface of the tower in a position above the plate, is an adjustable slab brace frame which serves to hold the upper surface of a given sidewalk slab while it is being lifted.The lifting tower also has on its upper end outward extending frame members. When lifting a damaged sidewalk, multiple lifting devices may be used and supplied with hydraulic bottle jacks which fit on the outside edge of the lifting towers.A method of leveling sidewalks is also disclosed this method includes lifting a sidewalk slab to be leveled then injecting mason's sand into the cavity created between the lower surface of the sidewalk and the settled earth below it.

Abstract: The present application discloses a sidewalk lifting device made of steel framed tower that has a flat plate extending inward from the lowest end of the tower. This plate holds the lower surface of a sidewalk slab and also provides the lifting surface to elevate a damaged sidewalk. Additionally, attached to the inside surface of the tower in a position above the plate, is an adjustable slab brace frame which serves to hold the upper surface of a given sidewalk slab while it is being lifted.The lifting tower also has on its upper end outward extending frame members. When lifting a damaged sidewalk, multiple lifting devices may be used and supplied with hydraulic bottle jacks which fit on the outside edge of the lifting towers.A method of leveling sidewalks is also disclosed this method includes lifting a sidewalk slab to be leveled then injecting mason's sand into the cavity created between the lower surface of the sidewalk and the settled earth below it.