Heidelberger Druckmaschinen Ag

Raimund Schröder

Karl-Heinz Helmstädter

Christian Hieb

Markus Gerstenberger

Christian Görbing

Thorsten Eckart

A machine processing printing-material sheets contains a first sheet transport drum and a second sheet transport drum disposed immediately after the first sheet transport drum in a sheet transport direction. The first sheet transport drum has gripper systems which describe a gripper flight circle during its rotation and a drum profile deviating substantially from a circular shape with outer contour regions running between the gripper systems and set back from the gripper flight circle. The second sheet transport drum has a sheet support surface with pneumatic grooves formed therein. The sheet support surface is composed of a first and second comb segments each with segment prongs. The pneumatic grooves are introduced into the segment prongs of at least one of the comb segments. The pneumatic grooves are preferably introduced both into the segment prongs of the first comb segment and into the segment prongs of the second comb segment.

Sheet transport drum for a machine processing printing-material sheets

A reversing or turning assembly of a sheet-processing machine includes an impression cylinder having a circumferential surface for transporting sheets thereon for printing the sheets in a printing nip associated with the impression cylinder. Gripper devices are provided for gripping the printed sheets at a respective trailing edge thereof and for lifting the gripped sheets off the impression cylinder for reversing the gripped sheets. The circumferential surface of the impression cylinder is formed with recesses in a region thereof occupied by the trailing edge of the sheets, for permitting the gripper devices to penetrate or dip into the recesses to grip the sheet trailing edge. The recesses have a position being variable in circumferential direction of the circumferential surface of the impression cylinder for adapting to different sheet formats.

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Hockenheim, Germany

Raimund Schröder