UNLOADER FOR STORAGE BINS

The unloader uses a combination of a plurality of auger and casing units arranged end to end and separably coupled together in a circular bin which has a floor provided with a center outlet sump leading to any means to carry loose granular material from the sump. A power unit connected to the first auger, is mounted in the sump so it can be rotated on a vertical axis that is on the central axis of the bin. The power unit also includes a hydraulic pump. The casings have openings in one side with manually removable doors for them so that grain may be received by or blocked out of the augers. The first casing carries a tank for hydraulic fluid near the pump. Near the end of the casing remote from the sump, a drive and support unit carries the casing and is hydraulically driven. The second auger and casing unit is separably coupled to the first auger and casing unit and extends axially beyond it. It also has near its outer end a drive support unit essentially like the one on the first auger. The hydraulis drive coupling to the pump is such that when the first auger and casing unit is separated from the second auger and casing unit, this will limit the supply of fluid to the hydraulic motor of the first drive and support unit so it can be used to cause the first casing unit to travel around the sump and remove the material from the center of the bin while the second unit remains buried in the pile of material in the outer portion of the bin. Unloading a bin by this method keeps the outward pressure on the entire circumference of the bin wall until center annular areas of the bin floor have been cleared and the outward pressure is lowered to a safe level.