Web-fed rotary printing machine

#1. Field of the Invention

#The invention relates to a web-fed rotary printing machine with at least one printing unit having at least one printing assembly which contains, arranged one above the other, a forme cylinder and an impression cylinder.

#2. Description of the Related Art

#FIG. 1 shows an intaglio printing unit in a side view,

#FIG. 2 shows the section II—II according to FIG. 1,

#FIG. 3 shows a flexographic design variant to FIG. 1,

#FIG. 1 shows a printing unit of a web-fed rotary printing machine with two forme cylinders 1, 2 and two impression cylinders 3, 4 which are mounted altogether, on each of the two sides, in a side wall 5, 6. Each side wall 5, 6 has an aperture 7 which is delimited by opposite panels 8, 9. The aperture 7 may also be designed, for example, as an open slot. Straight guide elements 10, 11 are arranged on the panels 8, 9.

#Each forme cylinder 1, 2 is mounted on each of the two sides, by means of its journal, in a slide 12 to 15. The impression cylinders 3, 4 are likewise mounted on each of their two sides in a slide 16 to 19. The slides 12 to 19 are mounted movably on the guide elements 10, 11 (FIG. 2). In order to provide a form-fitting slide guide, the guide elements 10, 11 have a T-shaped cross section, the crosshead of which engages into a correspondingly designed undercut channel 20 on each slide 12 to 19. For the purpose of movability, each slide 12 to 19 possesses a threaded nut which co-operates with a drivable threaded spindle mounted in the respective side wall 5, 6. These elements are not illustrated in the present application. They are described in DE 100 08 225.4, which corresponds to U.S. Pat. No. 6,397,743, which is incorporated herein by reference.

#The forme cylinder 1 constitutes, with the impression cylinder 3, a printing assembly 21, and the forme cylinder 2, with the impression cylinder 4, a printing assembly 22 for direct printing. Each forme cylinder 1, 2 is driven by its own drive motor 23, 24, advantageously by a variable-position electric motor. Drive motors 32, 33 are also advantageously provided on the impression cylinders 3, 4, but are not connected up in the configuration shown. They may also be separated in drive terms from the impression cylinders 3, 4 by means of couplings. The impression cylinders 3, 4 are therefore driven by friction. On the other hand, it is also possible for them to be driven by means of the drive motors 32, 33.