Rotary printing press

Abstract

In a rotary printing press with a printing cylinder and a counter roller, such as an impression cylinder, for example, and a print web guided between them, faultless print quality across the entire width is attained, even with an extremely wide print web and a correspondingly slim printing cylinder. The printing cylinder is provided with a fixed support and a jacket, which is rotatable around it, and is supported by a row of support elements with a printing pressure which is controlled individually or in groups. With this arrangement, a uniform printing pressure profile across the print web width and, simultaneously, a print gap which is generally uniform are attained. Deformations and displacements of the printing cylinder jacket cross-wise to the printing plane are avoided in that additional cross-bracing elements for exerting a restoring force on the printing cylinder jacket cross-wise to the printing plane are provided. The restoring force of the cross-bracing elements is controlled by position sensors or bearing pressure sensors in such a way that the position of the printing cylinder jacket is maintained even with particularly lengthy and slim printing cylinders. Oscillations of the printing cylinder are prevented by hydrostatic support elements which have a damping effect.