Dual mode tamper/offsetter

In a sheet stacking and job separating system for the printed sheet output of print jobs of a reproduction apparatus, in which, repeatedly, plural said printed sheets are compiled as a print job set by being tamped into a squared stack in a compiler with a tamper system, and said compiled print job set stack is ejected from said compiler onto an output stacking tray holding plural said print job set stacks in a common stack, and wherein respective said print job set stacks are stacked offset from one another in said output stacking tray:

• the improvement comprising a dual mode print job set stack tamper and job sets offsetting system, wherein in a first mode, said tamper system tamps said print job set into a squared stack in said compiler while retaining said print job set in a defined stacking position;
• and wherein in a second mode said tamper system shifts a selected said print job set out of said defined stacking position into an offset position to provide said offset position of said print job set in said output stacking tray;
• wherein said tamper system includes a spaced pair of upstanding sheet tampers between which said printed sheets are compiled, and a dual mode tamper drive system, and wherein in said first mode at least one of said tampers is driven towards the other said tamper to tamp said print job set into a squared stack in said defined stacking position by said dual mode tamper drive system, and wherein in said second mode said dual mode tamper drive system causes said tampers to move cooperatively to shift said print job set out of said defined stacking position into said print job set offset position;
• wherein in said second mode said dual mode tamper drive system is connected to both said tampers to move both said tampers in the same direction by a selected print job set offsetting distance;
• wherein said dual mode tamper drive system has a single drive motor which is differently connected to said tampers in said first mode than said second mode;
• wherein said dual mode tamper drive system comprises a clutching system and a belt drive system directly driven by said single drive motor and connecting with both said tampers by said clutching system, which belt drive system in said first mode is connected by said clutching system to both said tampers at portions of said belt drive system which are moving in opposing directions, and which belt drive system said second mode is connected by said clutching system to both said tampers at respective portions of said belt drive system which are moving in the same direction.