Patent ID: 8322720

Claim:
A printing device comprising: a sheet buffer including a paper path having a plurality of nip pairs for selectively receiving and releasing a plurality of printer sheets; said plurality of nip pairs including a fixed load nip pair, a fixed center nip pair, and a fixed unload nip pair; said plurality of nip pairs further including at least a first and a second releasable nip pair, said first nip pair between said load nip pair and said center nip pair and said second nip pair between said unload nip pair and said center nip pair; a controller for controlling the device such that each subsequent sheet of said plurality of sheets is shingled over a previous sheet wherein said first and second nip pairs selectively releasable for loading and unloading a first size printer sheet in a first in first out order in said sheet buffer; said plurality of nips further including at least a third and a fourth releasable nip pair, said third nip pair between said load nip pair and said first nip pair and said fourth nip pair between said unload nip pair and said second nip pair wherein each subsequent sheet of said plurality of sheets is shingled over a previous sheet wherein said third and fourth nip pairs selectively releasable for loading and unloading a second size printer sheet in a first in first out order within a buffering zone; and, said first nip pair, said second nip pair, said third nip pair, and said fourth nip pair selectively releasable for loading and unloading a third size printer sheet in a first in first out order within said buffering zone.