Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A device for transferring a sheet via a peripheral region of a cylinder includes an airflow-generating device for applying at least one air flow to the peripheral region of the cylinder, with which the sheet is associated, the airflow being directed in a direction of rotation of the cylinder; and a method of operating the device for transferring a sheet via a peripheral region of a cylinder.

Abstract: A device for transferring a sheet via a peripheral region of a cylinder includes an airflow-generating device for applying at least one air flow to the peripheral region of the cylinder, with which the sheet is associated, the airflow being directed in a direction of rotation of the cylinder; and a method of operating the device for transferring a sheet via a peripheral region of a cylinder.

Abstract: A transport drum in a rotary printing press, having a covering for preventing a fresh printed product from being smeared when the printed product is being transported through the press, the covering being secured to the jacket surface of the transport drum and being formed of a carrier material, includes resiliently embodied filamentary support elements secured in the carrier material of the covering, and an ink-repellent material applied to outer ends, respectively, of the support elements.

Abstract: A suction-air control device for controlling suction air applied to suction openings of a printing-press cylinder, having controllable valves by which the suction openings are connectable to a suction-air source, and a first pneumatic control device for timed or cyclically feeding the suction air, includes a second pneumatic control device for controlling the suction air in a manner dependent upon the format of the printing substrate, the valves being pneumatically controllable and being disposed on the cylinder.

Abstract: A device for controlling vacuum applied to suction openings formed in a cylinder, the suction openings being connectable to a vacuum source via valves arranged in rows and assigned to the suction openings, includes a rotatable adjusting shaft carrying adjusting elements assigned to the valves, the adjusting elements serving to actuate the valves in a defined sequence when the adjusting shaft is rotated, the valves having adjusting bodies therein movable by the adjusting elements out of a first switching position of the adjusting bodies into a second switching position thereof, the vacuum applied to the suction openings being of different magnitudes in the first and the second switching positions; and a method for incrementally actuating the vacuum-controlling device.