This application claims the priority of German Patent Document No. 10 2004 043 503.0, filed Sep. 9, 2004, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a printing unit for a press.
Printing units of web-fed rotary presses, in particular of newspaper presses, have a plurality of press units, each press unit comprising a transfer cylinder, a form cylinder and an inking unit and damping unit. Furthermore, such printing units can have impression cylinders, it being possible for an impression cylinder to interact with one or more transfer cylinders of different press units. In addition to printing units which have such impression cylinders, printing units which have no impression cylinder are also known, the transfer cylinders of two press units rolling on each other in such printing units without impression cylinders. The transfer cylinders are also designated blanket cylinders, and the form cylinders are also designated plate cylinders. The form cylinders or plate cylinders bear printing forms.
When printing with a printing form, a distinction is in principle drawn between methods which, on the one hand, operate with a printing form which can be written once and, on the other hand, operate with a rewritable printing form. Printing methods which use rewritable printing forms are also summarized under the keyword “computer to press/direct imaging”. The present invention relates to a printing unit for a press which operates with rewritable and erasable printing forms. The applicant markets digital presses which operate with rewritable and erasable printing forms, under the product description “DICOweb”.
The principles of the DICOweb technology are described in “Handbuch der Printmedien [Handbook of print media], Helmut Kipphan, pages 674 to 680, year 2000, Springer-Verlag”. Printing units which operate with such rewritable and erasable printing forms have, in addition to the subassemblies described above, at least one imaging device for imaging and/or de-imaging the rewritable and erasable printing forms positioned on the form cylinders.
Press units of web-fed rotary presses are increasingly being designed more compactly, that is to say with smaller dimensions. As a result, the overall room available on the printing units of a press is reduced, that is to say the space available for positioning and arranging the inking units, damping units and imaging devices. Furthermore, in the case of printing units having compact designs, access to the cylinders, specifically to the form cylinders and transfer cylinders, is made more difficult. In the case of printing units having small dimensions, the integration of inking units, damping units and imaging devices into the press while simultaneously ensuring simple access to the form cylinders and transfer cylinders of the printing units is already presenting considerable difficulties.
On this basis, the present invention is based on the problem of providing a novel type of printing unit for a press.
According to an embodiment of the invention, the inking unit, if appropriate together with the damping unit, can be pivoted with respect to a preferably fixed form cylinder from a printing position into a rest position, it being possible for the imaging device to be pivoted with respect to the preferably fixed form cylinder from an imaging position into a rest position, the imaging device being pivoted into a rest position when the inking unit and, if appropriate, damping unit is pivoted into the printing position and, when the imaging device is pivoted into the imaging position, the inking unit and, if appropriate, the damping unit being pivoted into a rest position. It is also possible for the inking unit and, if appropriate, the damping unit and also the imaging device to be pivoted into the respective rest position, simple access to the cylinders of the printing unit then being ensured.
In an alternative embodiment of a press unit according to the invention, by means of a translational relative movement between the form cylinder of each print unit and the corresponding imaging device, which movement runs in the direction of the longitudinal axis of the form cylinders, the respective press unit can be transferred from printing operation to imaging operation.
Both embodiments of the invention ensure simple integration of inking units, damping units and imaging devices in printing units of presses having compact designs. By means of translational or pivoting movements between the form cylinders and inking unit, damping unit and the imaging devices, the overall space available may be utilized optimally and, furthermore, simple access to the cylinders of the printing unit is ensured. In the sense of the present invention, either the, or each, imaging device can be moved toward the respective form cylinders of the printing unit or, on the other hand, the form cylinders can also be moved towards the, or each, imaging device. In this case, as mentioned, either translational or pivoting movements are utilized.
Preferred developments of the invention emerge from the following description. Exemplary embodiments of the invention will be explained in detail, without being restricted thereto, by using the drawings, as described below.
In the following text, the present invention will be described in greater detail with reference to FIGS. 1 to 6.
FIGS. 1 to 3 show a first exemplary embodiment of the present invention using the example of a printing unit 10 of a web-fed rotary press with a vertical web run. The web run of the printing material through the printing unit 10 in
In the exemplary embodiment of FIGS. 1 to 3, the printing unit 10 has a total of eight press units 12, each of the press units 12 having a form cylinder 13 and a transfer cylinder 14. Rewritable and erasable printing forms are positioned on the form cylinders 13; the printing unit 10 is accordingly designed as what is known as a “computer to press/direct imaging” printing unit. The form cylinders 13 are also designated plate cylinders. As a rule, rubber blankets are positioned on the transfer cylinders 14, for which reason the transfer cylinders 14 are also designated rubber-covered cylinders. It can be gathered from
In addition to the form cylinders 13 and transfer cylinders 14, each printing unit 12 in the exemplary embodiment of FIGS. 1 to 3 is assigned an inking unit, a damping unit and an imaging device. The inking unit and damping unit are used to apply printing ink and damping solution to a printing form positioned on the form cylinder 13 of a press unit 12. The imaging devices are used for de-imaging or erasing and imaging the printing forms positioned on the form cylinders.
In order to integrate inking units 15, damping units 16 and imaging devices 17 into the printing units 10 despite the small amount of space available in such printing units 10 and, furthermore, to ensure simple access to the cylinders 13 and 14 of the printing units 10 for maintenance work in particular, in the sense of a first aspect of the present invention it is proposed to construct the inking unit 15 and the damping unit 16, on the one hand, and the imaging device 17, on the other hand, of each press unit 12 such that it can be pivoted.
Thus,
In the exemplary embodiment of FIGS. 1 to 3, for each press unit 12 individually or separately, the corresponding inking unit 15 and the corresponding damping unit 16 and the corresponding imaging device 17 can be pivoted relative to the fixed form cylinder 13 of the press unit 12. The pivotable inking unit 15 and damping unit 16 are in this case constructed as individually driven units.
In the exemplary embodiment of
The common factor in the two exemplary embodiments according to FIGS. 1 to 4 is that the easy integration of the inking unit 15, damping unit 16 and imaging device 17 into one printing unit of compact design, and also the easy accessibility of the cylinders 13 and 14 of the printing units 10 is implemented by means of pivoting movements of the inking unit 15 and damping unit 16, one the one hand, and of the imaging device 17, on the other hand. In the following text, with reference to
As distinct from the exemplary embodiment of
With reference to FIGS. 1 to 6, the present invention has been described by using the example of web-fed rotary presses with vertical web guidance. It should be pointed out that the invention can of course also be used in web-fed rotary presses with horizontal web guidance. Likewise, the invention can be used in printing units whose transfer cylinders roll on what are known as impression cylinders.
List of reference symbols:
The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.
Number | Date | Country | Kind |
---|---|---|---|
10 2004 043 503.0 | Sep 2004 | DE | national |