BOGENLEITEINRICHTUNG IN BOGENAUSLEGERN VON DRUCKMASCHINEN

摘要

Grippers pull the leading ends of sheets along a sheet transport path, and a guidance structure facilitates sheet travel. The guidance structure comprises a plurality of longitudinally extending guide bars provided with suction openings, the ribs spaced apart transverse to the sheet-transport direction. Intermediate the bars are large-surface-area plates having suction openings. When guiding sheets printed on only one side, the intermediate suction plates are at about the same level as the longitudinally extending guide bars, and the entire face of the sheet is engaged, with the help of suction force. When guiding sheets printed on both sides, the imtermediate suction plates all drop down out of contact with the sheet, leaving only the spaced apart and narrow longitudinal guide bars to engage the sheet. The guide bars are furthermore transversely shiftable, so that they can be brought into engagement with parts of the sheets bearing no printing.