ROTOGRAVURE UNIT INCLUDING A PULL ROLLER AND NARROW-WEB ROTARY PRINTING MACHINE

Abstract

A rotogravure unit of a printing machine for printing on a web-shaped printing material includes a forme cylinder, an ink application device, an impression cylinder and guide rollers for guiding the printing material. A driven pull roller and a further roller form a roller pair for transporting the printing material. The rotogravure unit advantageously permits only a few waste products to be created when the machine is started up or restarted and in-register printing is made quickly possible.

Claims

1. A rotogravure unit of a printing machine for printing on web-shaped printing material, the rotogravure unit comprising: a forme cylinder; an ink application device associated with said forme cylinder; an impression cylinder associated with said forme cylinder; guide rollers for guiding the printing material; and a driven pull roller and a further roller, said pull roller and said further roller forming a roller pair for transporting the printing material.

2. The rotogravure unit according to claim 1, wherein said pull roller is disposed upstream of said forme cylinder.

3. The rotogravure unit according to claim 1, wherein said pull roller is engaged with said impression cylinder.

4. The rotogravure unit according to claim 1, wherein said further roller is a counterpart roller, and said pull roller is disposed upstream of said impression cylinder and forms said roller pair with said counterpart roller.

5. The rotogravure unit according to claim 1, which further comprises a servomotor associated with said pull roller, and a machine control unit for actuating said servomotor.

6. A narrow-web rotary printing machine, comprising: a plurality of printing units, at least one of said printing units being a rotogravure unit according to claim 1.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0023] FIG. 1 is a fragmentary, diagrammatic, front-elevational view of a first embodiment of a rotogravure unit of the invention;

[0024] FIG. 2 is a fragmentary, front-elevational view of a second embodiment of a rotogravure unit of the invention; and

[0025] FIG. 3 is a fragmentary, front-elevational view of a prior art rotogravure unit.

DETAILED DESCRIPTION OF THE INVENTION

[0026] Referring now in detail to the figures of the drawings, which are not to scale and in which elements and components that correspond to one another have the same reference symbol, and first, particularly, to FIG. 3 thereof, there is seen a rotogravure unit 10 constructed in accordance with the prior art for printing on a web of printing material 100. A supporting structure of the printing unit 10 is formed by a printing unit frame 1. As is indicated by an arrow b, the web of printing material 10 passes through the rotogravure unit 10 as follows: coming from a non-illustrated upstream printing unit or a non-illustrated upstream processing unit, the web of printing material 100 travels into the rotogravure unit 10 through a web tension compensation device 4, where it is guided between a gravure cylinder 3 and an impression cylinder 2 by a first guide roller 5 to receive a print. Then the web of printing material 100 is guided by a second guide roller 5 before it leaves the gravure unit 10 to move on to a non-illustrated downstream further printing unit or a non-illustrated downstream processing unit. The forme cylinder 3 is driven by a servomotor 7 which is hidden behind the plane of the drawing. Thus, only a drive axle of the servomotor 7 is indicated in the figures. An ink application device 6 including an ink fountain and a doctor blade applies ink to the forme cylinder 3, which transfers the ink to the web of printing material 100.

[0027] FIG. 1 illustrates a rotogravure unit 10 in accordance with the invention. The rotogravure unit 10 includes a printing unit frame 1 for receiving elements and components of the rotogravure unit 10. An ink application device 6 including an ink fountain and a doctor blade applies ink to a forme cylinder 3, which transfers the ink to the web of printing material 100. The web of printing material 100 is transported through the rotogravure unit 10 in a direction of web travel b and a direction of transport T. The forme cylinder 3 and the impression cylinder 2 form a printing nip through which the web of printing material 100 is transported to receive the print. In order to transfer a print, the forme cylinder 3, which is driven by a servomotor 7, is equipped with otherwise non-illustrated printing formes.

[0028] In the embodiment shown in FIG. 1, a pull roller 8 is disposed immediately upstream of the impression cylinder 2 and is engaged with the latter. Thus, the impression cylinder 2 and the pull roller 8 form a roller pair to create a nip or clamping location in which the web of printing material 100 is guided and transported in a defined way. The pull roller has a servomotor 8.1, which is not shown in any detail in FIG. 1. Non-driven co-rotating guide rollers 5 are provided to further guide the web of printing material 100.

[0029] The ink application device 6 may alternatively be constructed as a chambered doctor blade system.

[0030] In the embodiment shown in FIG. 2, the rotogravure unit 10 likewise has a pull roller 8 driven by a servomotor 8.1. The pull roller 8 interacts with a counterpart roller 12 to form a pull roller pair and a clamping location for the web of printing material 100. The pull roller 8 and the counterpart roller 12 are disposed upstream of the impression cylinder 2 in such a way as to be spaced apart from the latter but still within the rotogravure unit 10.

[0031] The ink application device 6 may alternatively be constructed as a chambered doctor blade system.

[0032] The drives 7, 8.1 of the rotogravure unit 10 may be actuated by a control unit 9 (see FIG. 3).

[0033] The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention:

LIST OF REFERENCE SYMBOLS

[0034] 1 printing unit frame [0035] 2 impression cylinder [0036] 3 forme cylinder [0037] 4 web tension compensation device [0038] 5 guide roller [0039] 6 ink application device [0040] 7 forme cylinder servomotor [0041] 8 pull roller [0042] 8.1 pull roller servomotor [0043] 9 control unit [0044] 10 rotogravure unit [0045] 12 counterpart roller [0046] 100 web of printing material [0047] b direction of web travel