Abstract: This invention relates to a discharge apparatus for storage bins and tanks having a central bottom outlet opening to allow a discharge conveyor to remove bulk material and a sweep conveyor within the storage bin, the improvement is that the outlet opening is adapted so that the sweep conveyor can be driven by its own motor or through gearing means driven by the discharge conveyor motor. A bearing support is provided for mounting the sweep conveyor with its own motor, and a structure is provided to mount a gear box connectably drivable by the discharge conveyor. The gear box arrangement comprises an upper and lower conventional gear box, together with a clutch to engage or disengage the sweep conveyor as required. Another improvement resides in having the sweep auger of the single drive system detachable. A further improvement lies in supplying a broom auger, in parallel with the sweep auger.