Large or flimsy sheets stacking system for disk type inverter-stacker

In a disk-type inverter-stacker system with plural rotatable fingers extending radially from an axis of rotation for sequentially inverting and stacking onto a stacking tray normal or larger size printed sheets outputted by a reproduction apparatus by temporarily retaining at least the leading edge portion of the sheet in sheet transporting slots of a defined length defined by inside surfaces of said rotatable fingers, the improvement comprising:

• at least one sheet corrugating member spaced from but interdigitated with at least two of said plural rotatable fingers, said sheet corrugating member extending radially from said axis of rotation slightly radially beyond said inside surfaces of said rotatable fingers to slightly corrugate said leading edge portion of said sheet while said sheet is in said slots defined by said rotatable fingers to provide improved said inverting and stacking onto said stacking tray of larger size sheets exceeding said defined length of said slots;
• wherein said sheet corrugating member is stationary and does not rotate with said rotatable fingers;
• and
• wherein said sheet corrugating member causes said larger size sheets exceeding the length of said slots to form an extended loop in said larger size sheets extending above said stacking tray.