Patent ID: 6079906
Filing Date: 2000-06-27
Classification: E02D

Abstract:
A method for making foundation piles in soil with a drilling device comprising an auger, means for rotating said auger and means for controlling the longitudinal travel thereof; said auger including two concentric tubes, an outer tube occupying an upper part of the auger and an inner tube projecting partially as a prolongation of the upper part and occupying a lower part of the auger, the inner tube having a first screw and the outer tube having one of a second screw and a plurality of blades, both of said tubes being displaceable with respect to each other, and said means for rotating and said means for controlling longitudinal travel being independent for each one of the tubes, said, method comprising the steps:rotating the inner tube in a first direction;simultaneously rotating the outer tube in an opposite direction of the first tube and advancing the auger through said soil whereby the soil is compacted against a wall of a formed hole by the combined action of the first screw and the one of the second screw and plurality of blades of the inner and outer tubes.