Patent ID: 6988724

Claim:
A sheet-fed printing apparatus comprising: a) a delivery section capable of receiving a stack of printed sheets; b) a transport element for transporting a printed sheet to a release position to drop said printed sheet in said release position; c) shielding element for shielding said delivery section and said transport element from an external environment of said sheet-fed printing apparatus, said shielding element being constituted to shield at least a side of said sheet-fed printing apparatus perpendicular to a transport direction of said printed sheet, and having an opening permitting said printed sheet dropped at said release position to pass through to an outside of said sheet-fed printing apparatus; d) a first sheet-trapping element being constituted at said opening and movable between a closed position for closing said opening and an open position for opening said opening; and e) a second sheet-trapping clement capable of stopping the leading edge of said printed sheet to be discharged through said opening to hold said printed sheet, wherein said printed sheet is discharged to said delivery section to be stacked when said first sheet-trapping element is in said closed position, and is discharged out of said sheet-fed printing apparatus when said first sheet-trapping element is in said open position, said first sheet-trapping element and said second sheet-trapping element are in interlocking and meshing engagement with each other, and are individually pivotable; and said second sheet-trapping element is in an inoperative position when said first sheet-trapping element is in said closed position, and is in an operative position when said first sheet-trapping element is in said open position.