GB2094717A

GB2094717A - Collect-printing unit for security printing for use in a rotary printing press

Info

Publication number: GB2094717A
Application number: GB8207456A
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: DE3109963C2; JPS57160640A; DE3109963A1; GB2094717B; FR2501583B1; FI77816B; CH655051A5; FI820619L; FI77816C; JPH0241412B2; FR2501583A1

Abstract

Collect-printing unit for security printing in dry 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 letterpress 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 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 dry offset printing for use in a rotary 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 cylinders carrying letterpress printing plates are disposed around one blanket cylinder. Each forme cylinder has an inking unit coordinated to this forme cylinder.

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 cut-out elastic cylinders have become known in the art from US Patent No. 3 390 631.

Disclosure ofthe invention It is an object of the present invention to provide a printng unit for dry-offset collect-printing from letterpress printing formes, which is suitable for printing one line, or a plurality of lines in multi-color printing as 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 dryoffset collect-printing. It is a further particular advantage that there is no necessity of providing an ink collecting cylinder, collecting the inks of different colors before transferring them onto the printing plate. A further advantage is on the other hand, that there is no necessity of providing a plurality of forme cylinders for printing a background of multi-color security lines. Thus, laboured adjustment and precise registering of the individual printing plates to each other are superfluous. It is possible to utilize letterpress printing plates which permit obtaining a printed image of a quality which may be put in the same category with dry-offset printing.The width of the lines on the printing forme is approximately maintained when the lines are transferred onto the support to be printed. The external contours of the lines and print areas are sharply marked-off and present a uniform ink coverage. There are no "squeezed margins", which cannot be avoided in dry-offset printing from a hard forme onto a support to be printed, nor inexact ink coverages of the printed lines and areas.

It is a further advantage that a forme cylinder can be coordinated to the blanket cylinder acting as a counter-pressure cylinder, which carries for example a plurality of printing plates being inked by so-called simultaneously be executed Brief description ofthe drawings While the novel features of the collect-printing unit for security printing for use in a rotary printing press in accordance with the present invention are set forth with particularity in the appended claims, a fuil 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 offset printing means.

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.

Aforme cylinder 23 cooperates with the blanket cylinder 8, on whose periphery one single blanket can be fixed, or a 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 letterpress printing plates 24, 26, 27. The letterpress printing plates 24,26,27 are inked by means of sectorialiy cut-out elastic cut-out rollers 28, 29,30,31 which have already become known in the art. Inking units 3334,36,37 are provided for inking the cut-out rollers 28,29,30,31, one inking unit 33; 34; 36; 37 being coordinated to one cut-out roller each.The peripheries of the blanket cylinder 8 and the forme cylinder 23 are of the same length and are an integral multiple of the periphery of the cut-out rollers 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 rollers 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 support to be printed, for example sheet 2, can simultaneously be printed in recto and verso printing under pressure interposed between the blanket cylinder 8 and a blanket cylinder 13. In this case the blanket cylinder 13 being covered with one blanket or a plurality of blankets 9, 11, 12 can be inked by offset printing plates 38,39,41,42 fixed on the offset plate cylinders 14,16, 17, 18. The offset printing plates 38,39,41,42 are inked by an inking unit 43,44, 46,47 coordinated to each of them. The peripheries of the blanket cylinders 8 and 13 are of equal length, and the peripheries of the offset plate 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 plate cylinders 14,16,17,18.

It would, however, be possible as weil to provide 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 ^,^, ll . t vithnl It n rinnUre} 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.

Claims

1. Acollect-printing unit for security printing in dry-offset printing for use in a rotary printing press, provided with a forme cylinder on whose periphery one or more letter-press printing formes are fixed, with a pluraity of sectorially cut-out, driven cut-out rollers disposed around the forme cylinder, which ink the or each letterpress printing forme, one inking unit being coordinated to each of the cut-out rollers, characterised by the improvement that one blanket cylinder (8) is coordinated to the sectorially inked forme cylinder (23), which transfers the multi-color printing images gathered on its blanket or respectively on its plurality of blankets (1,21, 22), onto a support (2) to be printed (2).

2. A collect-printing unit for use in a rotary printing press in accordance with Claim 1, characterized by the improvement that a counter-pressure cylinder (13) co-operating 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 by the improvement that the counter-pressure cylinder (13) comprises a blanket cylinder (13), that this blanket cylinder (13) is provided either with one blanket extending over approx. the whole periphery of the blanket cylinder (13) or with a plurality of blankets (9; 11; 12) each of them extending over a part of the blanket cylinder periphery.

4. A collect-printing unitfor use in a rotary printing press in accordance with any one of claims 1 to 3, characterized by the improvement that a plurality of offset plate cylinders 16,17,18) carrying offset printing plates (38,39,41,42) with their respective inking units (43,44,46,47) are coordinated to the blanket cylinder (13).

5. Acollect-printing unitforuse in a rotary printing press in accordance with claim 1, characterized by the improvement that a second blanket cylinder (8) is coordinated to the blanket cylinder (8), that a second sectorially inked forme cylinder (23) on whose periphery letter-press printing plates (24,26, 227) are fixed, cooperating with the second blanket cylinder (8), is provided, said letterpress printing plates (24,26,27) being inked by sectorially cut-out elastical cut-out rollers (28,29,30,31), and that one inking unit (33; 34; 36; 37) is coordinated to each of the cut-out rollers (28; 29: 30: 31).

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