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US 4,024,814 AGranted
Transfer drum in sheet-fed rotary printing presses
AssigneeHeidelberger Druckmaschinen AG
InventorWilli Becker
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AssigneeHeidelberger Druckmaschinen AG
InventorWilli Becker
Estimating the term…
A sheet-fed rotary printing press includes a transfer drum assembly includes a rotatable transfer drum having a sheet-supporting peripheral surface, a gripper device carried by the transfer drum for gripping the leading edge portion of a sheet being transferred, and a suction device secured to the transfer drum at the end of the peripheral sheet-supporting surface, as viewed in rotary direction of the transfer drum, for gripping the trailing edge portion of the sheet. The suction device includes a plurality of suckers having suction surfaces disposed in the peripheral surface of the transfer drum and formed with respective suction orifices. The suction surfaces have respective centers and the suction orifices are located eccentrically to the centers, respectively, each of the suction orifices being adjustable so as to apply suction force to a sheet at successively varying locations eccentric to the respective suction surface center for tensioning the sheet in a direction opposite to the rotary direction of the transfer drum.
In a sheet-fed rotary printing press, a transfer drum assembly comprising a rotatable transfer drum formed with a sheet-supporting peripheral surface having at least two ends circumferentially spaced about said transfer drum, a gripper device carried by said transfer drum for gripping the leading edge portion of a sheet being transferred, and a suction device secured to said transfer drum at one of said ends of said peripheral sheet-supporting surface for gripping the trailing edge portion of the sheet, said suction device comprising a plurality of suckers having movable suction surfaces disposed in the peripheral surface of said transfer drum, said suction surfaces being formed with suction orifices located therein, means for simultaneously moving each of said suction orifices in both an axial and circumferential direction relative to said peripheral surface so that a suction force applied through said orifices at the varying positions thereof simultaneously tensions the sheet in an axial and circumferential direction relative to said peripheral surface.
Dependencies are inferred from the claim text.