Patent Application
20080236061
1. Field of the Invention
The present invention relates to correcting settlement of building slabs and more particularly, to structural devices for such procedures.
2. Description of the Prior Art
Basement walls and slabs have long been jacked up through hydraulic or screw jacks when settlement has occurred. The jacks connect to the walls through various bracket means, often a bolted plate, and the jack left in place. When used for jacking floor, driveway or other such flat slabs, a hole must be bored through the concrete and a spreader support of some type placed below slab level, then the jack extended to lift the slab. The spreader support has been the subject of development and outwardly expanding toggle bolts, crossbars, and the like used and all subject to expense.
The present invention consists of a sleeve which fits into a hole bored in the concrete slab and which has allowance for brackets to extend outwardly of the sleeve and engage with the bottom surface of the concrete slab. The brackets are L shaped and inserted when the sleeve is in position. Next a threaded rod that has a bottom stop nut and a threaded positioning member is inserted through the sleeve and rotated so that the positioning member engages with the L shaped brackets to maintain them in an outwardly extended position. The rod is screwed snug so that the brackets engage and lift the slab. Thereafter, the top of the rod can be cut off and the sleeve cemented in place.
The principle objects and advantages of the present invention are:
To provide an economical yet sturdy slab support system;
To provide such a slab support system which is easy to use; and
To provide such a slab support system which is well adapted to the intended purposes.
Other objects and advantages will become apparent from the following description including an exemplary embodiment.
The reference numeral 1,
A pipe pier 5 is driven downwardly through the bored hole until the pier bottoms out against hard resistance. Typically the pier is 16-18 feet long, emplaced by a hydraulic ram and pushed down until 10,000 psi resistance. The top of the pipe pier 5 ends inches below the lower surface of the floor slab.
A sleeve 10 is inserted, as by hand, into the bore 2 and temporarily retained therein by a L shaped brackets 16 and 18 are extended by hand through the sidewall slots 12 and 14 of the sleeve 10 so that the bottom leg of the L bracket rests against the underside of the slab 3.
To hold the L shaped brackets 16 and 18 in position and lift the sleeve 10 in support of the slab, a threaded rod 22 is fitted with a stop, such as a stop nut 24 welded or otherwise affixed adjacent the rod lower end, but leaving enough rod length to extend down into the open top of the pipe pier 5. A threaded positioning member 28,
To engage the sleeve and position the L shaped brackets 16 and 18, the threaded rod 22 is extended downwardly through the sleeve 10 with the positioning member 28 rotated 90 degrees to avoid interference with the brackets 16 and 18. Once the rod is fully inserted and the stop nut 24 bears against the top of the pipe pier 5, the rod is rotated 90 degrees so that the positioning member contacts and supports the corners of each L shaped bracket 16 and 18, and tightening commenced. Once the rod 22 is tightened to installers recommended torque, the top exposed end of the rod 22 can be cut off and the sleeve 10 cemented or otherwise covered in place.
The brackets 16 and 18 hold the slab supported by the pipe pier. The brackets are far superior, stronger and less expensive than toggle bolts, bars, or other such load spreader mechanism.
It is to be understood that while certain forms of the invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown.
