GB2094718A

GB2094718A - Collect-printing unit for security printing for use in a rotary printing press

Info

Publication number: GB2094718A
Application number: GB8207457A
Authority: GB
Original assignee: Koenig and Bauer AG
Current assignee: Koenig and Bauer AG
Priority date: 1981-03-14
Filing date: 1982-03-15
Publication date: 1982-09-22
Also published as: GB2094718B; JPH0241414B2; CH655053A5; FR2501586B1; FI820621L; FI78644B; FI78644C; JPS57163571A; FR2501586A1; DE3109977C2; DE3109977A1

Abstract

A collect-printing unit for security printing in offset printing for use in a rotary printing press, provided with a blanket cylinder 8 and a forme cylinder 23 on whose periphery one or a plurality of offset printing formes are fixed, a plurality of so-called cut-out rollers 28, 29, 30, 31 being disposed for each forme cylinder, and one inking unit and one damping unit each being coordinated to each cut-out roller. This collect- printing unit for security printing for use in a rotary printing press is capable of being utilized in sheet fed rotary printing presses as well as in web-fed rotary printing presses. <IMAGE>

Description

SPECIFICATION Collect-printing unit for security printing for use in a rotary printing press Field of the invention The present invention is directed to a collectprinting unit for security printing in offset printing for use in a rotary sheet fed or web fed printing press.

Background art Collect-printing rotary printing presses for dry offset printing are generally well-known in the art. In such machines, however, a plurality of forme cyiinders carrying letterpress printing plates are disposed around one blanket cylinder. One inking unit each is coordinated to each of these forme cylinders. The blanket cylinder receives a multi-color ink coating from the forme cylinders. That is to say, a multi-color ink film is produced on the blanket cylinder, which is transferred onto said blanket cylinder by the letterpress printing plates.

So-called elastic cut-out rollers have become known in the art from US Patent No. 3390631.

Disclosure ofthe invention It is an object of the present invention to provide a printing unit for collect-printing in offset printing, which is suitable for multi-color printing of one line or a plurality of lines forming a safety background on security papers, and which permits printing such lines with continuous color change and free from register displacement.

It is a particular advantage of the present invention that lines or areas can be printed in continuous color change without any register displacement in offset collect-printing. It is a further particular advantage that there is no necessity of providing an ink collecting cylinder, collecting the inks of different colours before transferring them onto the printing plate. Afurther advantage is on the other hand, that there is no necessity of providing a plurality of forme cylinders for printing a background of security lines.

Thus, laboured adjustment and precise registering of the individual printing plates to each other are superfluous. It is possible to utilize offset printing plates to obtain an excellent printed image. The width of the lines on the printing forme is maintained when the lines are transferred onto the support to be printed. The external contours of the lines and color areas are sharply marked-off and present a uniform ink coverage. There are no "squeezed margins", which cannot be avoided in direct letterpress printing from a hard forme onto a support to be printed, nor inexact ink coverage on the lines or resp. the areas.

It is a further advantage that a forme cylinder can be coordinated to the blanket cylinder operating as a counter-pressure cylinder, this forme cylinder carrying for example a plurality of printing plates being inked by so-called cut-out rollers, so that recto and verso printing can simultaneously be executed.

Brief description of the drawings While the novel features of the collect-printing unit for security printing in offset printing for use in a rotary printing press in accordance with the present invention are set forth with paticularity in the appended claims, a full and complete understanding of the invention may be had by referring to the description of a preferred embodiment as set forth hereinafter and as may be seen in the accompanying drawing, which is: a schematic side view of a sheet-fed collectprinting rotary printing press with a printing unit in accordance with the present invention in cooperation with another offset printing unit.

Modes for carrying out the invention Sheets 2 to be printed arrive in a manner known in the art conveyed by means of conveyor tapes (not shown in the drawing) over a stop drum 3, a transfer drum 4, in well-known grippers (not shown in the drawing) of a blanket cylinder 8 (this being the case only if the supports to be printed are sheets).

One or more blankets 19, 21, 22 are fixed to the periphery of the blanket cylinder 8 and each has approximately the length of one printing plate.

Similarly, one or more blankets 9, 11, 12 are fixed to the periphery of a counter-pressure blanket cylinder 13 and each has approximately the length of the one printing plate. Regardless of whether the blanket cylinder 13 has one blanket or a plurality of blankets, it can be inked by offset printing plates 38, 39, 41, 42 fixed on offsetforme cylinders 14, 16, 17, 18.

Aforme cylinder 23 cooperates with the blanket cylinder 8, on whose periphery one single blanket can be fixed, or plurality of blankets 19,21,22 as well, each of them having approximately the length of one printing plate. The forme cylinder 23 carries around its periphery one or a plurality of offset printing plates 24, 26, 27. The offset printing plates 24, 26, 27 are inked by means of sectorially cut-out elastic cut-out rolls 28, 29, 30,31 which have already become known in the art.Offset inking units 33,34, 36,37 are provided for inking the cut-out rollers 28, 29,30,31, one offset inking unit 33,34,36,37 with one damping unit, 5,6,7, 10 each being coordinated to one cut-out roller 28, 29,30,31. The peripheries of the blanket cylinder 8 and the forme cylinder 23 are of the same length and are integral multiple of the periphery of the cut-out rollrs 28, 29,30,31. The peripheries of the cut-out rollers 28, 29, 30,31 are all of equal length.

All the cylinders 8, 13,23, 14, 16, 17, 18, and rolls 28,29,30,31, inking units 33,34,36,37 and drums 3, 4 are driven through a common drive gear train known in the art from a main motor 32. The damping units 5, 6,7, 10 are driven by a separate electric motor.

The support to be printed, for example sheet 2, can for example simultaneously be printed in recto and verso printing interposed under pressure between the blanket cylinder 8 and the blanket cylinder 13.

Each offset printing plate 38,39,41,42 is inked by one inking unit 43,44,46,47 coordnated to it. The peripheries of the blanket cylinders 8 and 13 are of equal length, and the peripheries of the offset forme cylinders 14,16,17, 18 are of equal length. The periphery of the blanket cylinders 8, 13 is an integral multiple of the periphery of the offset forme cylinders14,16,17,18.

It would, however, be possible as well to provided in mirror image disposition to the cylinders 8 and 23 with the cut-out rollers 28, 29, 30,31 and the inking units 33, 34,36,37 - another cylinder 8 and another cylinder 23 (however without grippers) with cut-out rollers 28,29,30,31 and inking units 33,34,36,37. If such a disposition is utilized, the support to be printed, for example a sheet 2, would simultaneously be printed in recto and verso printing, interposed between both blanket cylinders 8, 8.

The printed sheets 2 are for example conveyed by chain delivery means to a sheet delivery. If a paper web is utilized as a support to be printed, the printing paper web is guided in a manner known in the art for example into a sheeter by which the web is cut into sheets which are then delivered by a sheet delivery device.

Claims

1. Acollect-printing unitforsecurityprinting in offset printing for use in a rotary printing press, characterized by a forme cylinder (23), on whose periphery one or more offset printing plates (38, 39, 41,42) are fixed a plurality of sectorially cut-out, driven cut-out rollers (28,29,30,31) for inking the offset printing plates (38,39,41,42) disposed around the forme cylinder (23), one inking unit being coordinated to each of cut-out rollers (28,29, 30,31), and a blanket cylinder (8) coordinated to sectorially linked forme cylinder (23) for transferring the multicolor printing images gathered on its blanket or on its plurality of blankets (19,21,22) onto a support to be printed (2).

2. A collect-printing unit for use in a rotary printing press in accordance with claim 1, characterized by a counter-pressure cylinder (13) cooperating with the blanket cylinder (8) is provided.

3. A collect-printing unit for use in a rotary printing press in accordance with claim 2, characterized in that the counter-pressure cylinder (13) comprises counter-pressure blanket cylinder (13); and this blanket cylinder (13) is provided either with one blanket extending over approximately the whole periphery of the blanket cylinder (13) orwith a plurality of blankets (9; 11; 12) which each extend over a part of the blanket cylinder periphery.

4. A collect-printing unit for use in a rotary printing press in accordance with claim 3, characterized by a plurality of offset forme cylinders (14,16, 17, 18) carrying offset printing plates (38,39,41,42), with their respective inking units (43,44,46,47), are coordinated to the counter-pressure blanket cylinder (13).

5. Acollect-printing unit for use in a rotary printing press in accordance with claim 1, characterized in that a second blanket cylinder (8) is coordinated to the blanket cylinder (8); a second sectorially inked forme cylinder (23), on whose periphery offset printing plates (24, 26,27) are fixed, cooperates with the second blanket cylinder (8); said offset printing plates (24,26, 27) are inked by sectorially cut-out elastical cut-out rollers (28, 29,30, 31), and that one inking unit (33,34,36, 37) and one damping unit (5, 6,7, 10) are coordinated to each of the cut-out rollers (28,29,30,31).

6. Acollect-printinq unitforsecurity printing in offset printing for use in a rotary printing press, substantially as hereinbefore described with reference to the accompanying drawing.