Patent ID: 7328899
Filing Date: 2008-02-12
Classification: B41F

Abstract:
1. A sheet-fed printing machine comprising at least one electrically conductive cylinder for transferring sheets in the printing machine, an apparatus for fixing a sheet on a surface of said cylinder, during transfer in the machine, said apparatus including an electrode bar having an exposed unencumbered face extending in closely spaced apart parallel relation to an outer perimeter of said cylinder that extends along the width of the cylinder for imparting an electrical charge which adheres the sheet to the cylinder as the sheet is transported between the cylinder and the electrode, and an air directing device including a first portion disposed at a location adjacent an upstreamside of said electrode bar, as viewed in the sheet transport direction, upstream of where the sheet is exposed to the electrical charge of said electrode bar for directing air currents on to the sheet to preliminarily position the sheet onto the cylinder prior to the sheet being exposed to the electrical charge of said electrode, and said air directing device including a second portion disposed at a location adjacent a downstream side of said electrode bar, as viewed in the sheet transport direction, for directing air currents onto the sheet and further stabilizing the sheet on the cylinder subsequent to being exposed to the electrical charge of said electrode, said air directing device first portion including an air blasting box in the form of a hollow profile adapted for directing air streams against a sheet upstream of the electrode and an air blasting tube having a plurality of outlet openings from which air currents are directed onto the sheet, and said hollow profile having a groove-shaped region for receiving said electrode bar and air blasting tube.