A roller assembly for conveying stacked sheet material along a feed path. The roller assembly includes a first roller adapted for rotation within a housing, a second roller pivotally mounting about an axis to the housing and opposing the first roller to define a roller nip, a spring biasing mechanism operative to bias the second roller about the pivot axis toward the first roller to effect optimum frictional engagement of the roller nip with the face surfaces of the stacked sheet material and a transmission assembly operative to (i) transfer rotational motion of the first roller to the second roller, (ii) drive the first and second rollers in opposing directions to convey the stacked sheet material along the feed path, and (iii) facilitate pivot motion of the second roller about the pivot axis to vary the spacing of the roller nip and accommodate stacks of sheet material which vary in thickness.