Patent ID: 6957930

Claim:
Apparatus for the formation of a column of granular material in soil comprising a storage hopper in the vicinity of the base of said apparatus to hold said granular material to form at least one said column in said soil, a hollow shaft means to form a cavity in said soil, a rotary drive means to rotate a substantially linear hollow shaft element of said hollow shaft means about its axis, an axial force means that includes at least a part of the weight of said hollow shaft means to axially advance said hollow shaft element into said soil to a desired depth, a displaceable cap means at the soil penetrating end of said hollow shaft element to prevent soil from entering the hollow of said hollow shaft element advanced into said soil, said cap is displaced to expose said hollow to said cavity to form a flow path for passage of said granular material from said hollow into said cavity formed in said soil as said hollow shaft element is removed from said soil by applying axial force of a magnitude to overcome resisting forces including effects of soil strength and weight of said hollow shaft element, a conveyor means with a granular material pickup end at said storage hopper to incrementally convey said granular material to a delivery end at a reasonably fixed highest point of said conveyor to deliver a desired quantity of said granular material to a feed tank system in the vicinity of said delivery end, said feed tank system includes a feed tank with an entry means to accept said granular material and an outlet means for said granular material to pass through said feed tank system by force which includes fluid supplied under pressure into said feed tank system with said entry means closed when necessary to cause said granular material to flow to the outlet end of said feed tank system into and through said hollow shaft system into said cavity formed on withdrawal of said hollow shaft from said soil by said axial force means able to apply force of a magnitude to overcome resisting forces which include strength effects of said soil and weight of said hollow shaft system, means to support and align said feed tank system and said hollow shaft means to permit movement of said granular material from said storage hopper through said hollow shaft means and into said cavity to complete said column of said granular material in a substantially continuous manner.