Printing – Cleaning attachments
Reexamination Certificate
2000-09-28
2001-11-06
Eickholt, Eugene (Department: 2854)
Printing
Cleaning attachments
C101S350500, C101S401100
Reexamination Certificate
active
06311619
ABSTRACT:
FIELD OF THE INVENTION
A sheet-fed rotary printing machine of this type is known from EP 0620115 B1. At least two varnishing units are provided for the in-line coating of printing materials. In this case, the varnishing unit, which precedes in the sheet running direction, is designed as a flexographic printing unit with a forme cylinder which carries a letterpress printing form and which is in contact with the sheet-guiding impression cylinder, with a screened applicator roller for inking (coating), which is in contact with the forme cylinder, and with a throw-on chamber doctor which is connected to a feed pump for the supply of coating fluid and to a suction pump for the return of coating fluid.
One disadvantage of this is that, for renewed coating orders, the printing form on the forme cylinder has to be exchanged and, if appropriate, the original screen roller must be exchanged for a screen roller having a different scoop volume. The change of the printing form is complicated to carry out either manually or in an automated manner and, furthermore, stoppage times occur on the printing machine as a result of the resetting work.
DE 195 03 951 A1 disclosed a method and an apparatus for intaglio printing. According to this, the depressions (wells) of a rough intaglio printing form can be uniformly filled, as a basic screen, by an applicator device by means of a liquefiable substance, subsequently the substance material can be stripped away from the depressions in conformity with the image by means of an image-dot transfer device, and intaglio printing form, screened in this way in conformity with the image, can be inked by means of an inking system, so that intaglio printing can thereafter be carried out. After the printing operation, the intaglio printing form can be regenerated to the rough intaglio printing form and the depressions can subsequently be filled again.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, in view of the foregoing, an object of the present invention is to provide a sheet fed rotary printing machine having a printing unit for multi-colour printing and a coating unit which avoids the above-mentioned problems with such printing machines, can be used more universally with its printing units and coating unit and which substantially reduces set-up times.
The solution according to the invention makes it possible, in addition to producing a multi-colour print, to apply at least one in-line coating to a printing material. In this case, in addition to the known inking of the printing material by the metering of the quantity of coating fluid, the in-line coating can be carried out as image-conforming (subject-related) preferably in-line imaging with in-line coating.
For this purpose, the sheet-fed rotary printing machine, preferably controlled by means of a control desk, has, in addition to the printing units, at least one coating unit which is formed, at least, from a sheet-guide cylinder, a forme cylinder and a metering system, with a screened applicator roller as a rough intaglio printing form or with the forme cylinder itself as a rough intaglio printing form.
Furthermore, the solution according to the invention allows in-line coating in the coating unit and makes it possible to produce the intaglio printing form on the applicator roller or the forme cylinder outside the sheet-fed rotary printing machine in a separate device. In this case, a separate device of this type may also be arranged separately at or on a printing unit and/or a coating unit. The exchange of the applicator roller or forme cylinder between the coating unit and the separate device for producing the intaglio printing form can be carried out manually or preferably by means of a handling system. Alternatively, this principle may be transferred to a printing unit for multi-colour printing, if this printing unit has a forme cylinder as an intaglio printing form (direct intaglio printing) or an applicator roller as an intaglio printing form (indirect intaglio printing). The separate device for producing the intaglio printing form can thus also be arranged at or on at least one printing unit for multi-colour printing.
For example, the separate device for producing the intaglio printing form may be arranged above the coating unit on the latter. The separate device is assigned, adjacent to it, as a handling system, for example an industrial robot which extracts the applicator roller or the forme cylinder from the mountings of the coating unit and which supplies the said applicator roller or forme cylinder to the separate device for producing the intaglio printing form and returns it from the separate device into the respective mounting.
In a further design, the separate device for producing the intaglio printing form, furthermore, is assigned a magazine as a roller/cylinder store. In this case, the handling system again extracts the applicator roller or forme cylinder from the mountings and supplies the applicator roller or forme cylinder to the magazine and returns it from the magazine to the respective mounting. In this case, the production of the intaglio printing form on the applicator roller or the forme cylinder can be achieved in the magazine by means of the separate device.
The magazine may also be used, in the simplest form, as roller/cylinder mounting for the temporary safekeeping of the applicator roller and/or forme cylinder. Furthermore, the magazine may also be designed for receiving a plurality of applicator rollers and/or forme cylinders. The occupancy of the storage locations (for rollers/cylinders) in the magazine and/or the activation of the handling system and of the separate device for producing the intaglio printing form can preferably be controlled from a coupled control desk. In this case, the magazine also ensures a roller/cylinder sequence, such as is required at the separate device for producing the intaglio printing form and at the safekeeping position. The handling system, magazine and separate device are not restricted to being assigned to a coating unit, but an arrangement of these subassemblies may also be implemented at or on, in particular above at least one printing unit.
Several designs are suitable for a metering system. Thus, in a first design, a metering roller is assigned to the screened applicator roller (as a two-roller unit) and the coating fluid is supplied into the roller nip thus formed. In a second design, the screened applicator roller is assigned a chamber doctor which is coupled to a circulation system for the coating fluid. Finally, in a third design, at least one scoop roller is assigned to the screened applicator roller. The coating fluid is scooped from a supply tank and conveyed to the roller nip.
The screened applicator roller itself is designed as a rough intaglio printing form with depressions (wells) and webs as a basic screen. With regard to a single-sized forme cylinder of the coating unit, this screened applicator roller is designed at least with the same diameter or larger. Preferably for partially recurring printing orders, the diameter of the applicator roller is designed to correspond to an even-numbered fraction of a single-sized forme cylinder.
The forme cylinder has a covering, which receives the coating fluid, and, preferably, a cylinder pit. In a circular segment of the part circumference, the screened applicator roller has an evenly curved surface in the roller casing essentially congruently to the cylinder pit of the forme cylinder, this part circumference being capable of being executed in two designs.
In a first design, the part circumference, which is level with the top edge of the webs, is a smooth surface (without a basic screen), and, in a second design, the basic screen already described is provided, which is filled completely with a material in order to achieve an even surface.
In one design, the screened applicator roller is assigned a dispensing device for filling the depressions of the basic screen with a liquefiable substance, a stripping device for the image-conforming (subject-related) removal of the substance
Jung Ulrich
Richter Franz-Peter
Stahl Dietmar
Stamme Rainer
Eickholt Eugene
Leydig , Voit & Mayer, Ltd.
MAN Roland Druckmaschinen AG
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