Bunk silo unloader

A silo unloader for comminuting and collecting silage from a silage stack, said silo unloader being detachably connectable to and operable through a driven vehicle having an operator's cab, said silo unloader comprising:

• a) first and second, vertically oriented screw jacks including means selectively and simultaneously rotating both of said first and second screw jacks in synchronous and alternate clockwise and counter-clockwise directions;
• b) a cylindrical drum having a plurality of spiked teeth extending therefrom including means selectively rotating said drum about its longitudinal axis, said drum being rotatably carried and extending perpendicularly between said first and second screw jacks;
• c) first and second nut elements threadedly engaged to said first and second screw jacks, respectively, with either end of said drum being connected to said first and second nut elements, respectively, whereby rotation of said first and second screw jacks in said clockwise and counter-clockwise directions causes said first and second nut elements to travel thereon in traversing, upward and downward directions, respectively, with said drum thereby also traveling in upward and downward directions with said first and second nut elements and between said first and second screw jacks;
• d) first and second cutting wheels each having a plurality of spiked teeth extending from first surfaces of each, said first and second cutting wheels being rotatably connected to and movable with said first and second nut elements adjacent either end of said drum, respectively, and rotatable about parallel axes which lie transversely to said drum longitudinal axis;
• and
• e) means automatically rotating said first and second cutting wheels about said parallel axes in response to said rotation of said drum about said longitudinal axis.