JPH0364309B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a sammel printing mechanism for a rotary printing press for securities, which includes a printing cylinder on which a printing plate is stretched, an impression cylinder,
The present invention also relates to a type having a plurality of color separation rollers each having a partially convex plate surface, and an inking device is assigned to each color separation roller.

Prior Art In a known Sammel printing mechanism for a rotary printing press for indirect letterpress printing, a plurality of plate cylinders equipped with letterpress printing plates are arranged around a rubber cylinder, and the rubber cylinder prints a multicolor image using printing plates. A multicolored ink film is formed on the rubber cylinder. In this case, it is difficult to adjust (register) the plurality of plate cylinders with respect to each other;
The printed line will be interrupted or dislocated where the color has changed.

An elastic color separation roller with a partially convex printing surface is also known from US Pat. No. 3,390,631. However, in the case of an elastic color separation plate roller, the formation of a partially convex plate surface cannot be performed accurately.

OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide a sammel printing mechanism for a rotary printing press suitable for printing one or more lines as a multicolored anti-counterfeit background pattern on securities. It is possible to print without interruption or shift at the point where the color of the line to be changed is changed, there is no need for the color separation plate roller to have a soft surface, and the ink film formed on the printing plate is is divided into two multiple times.

Configuration of the Invention In order to achieve the above object, the configuration of the present invention includes the following:
A drivable blanket cylinder covered with a rubber blanket is provided between each color separation plate roller and the plate cylinder, each covered with a hard color separation plate, and the color separation plate transfers the ink to the rubber blanket. The ink received by the rubber blanket is transferred to the plate of the plate cylinder, and a portion of the ink transferred by the rubber blanket to the plate of the plate cylinder is transferred in the direction of rotation of the plate cylinder. It is then put back on to another rubber blanket.

Advantages of the Invention With the configuration according to the invention, lines or areas can be directly printed by letterpress Sammel printing without interruption or shift at the location where the color is changed.
Furthermore, it is no longer necessary to arrange a sammel cylinder which first collects the ink and then transfers it to the hard letterpress. There is also no need for a large number of printing plates with letterpress printing plates for printing multicolored line patterns. This avoids costly adjustment and registration of the individual reliefs with respect to each other. It is possible to produce an impression qualitatively equivalent to that of dry offset. Furthermore, the line width of the printing plate is approximately maintained during transfer to the printing carrier. Lines and contours of the printed surface are kept clear and a uniform printed image is obtained. During printing, non-uniform printed images that are unavoidable with rigid printing plates are avoided. A further advantage is that for precisely registered partial inking, hard color separation plates made of synthetic resin and having a long service life are used via color separation rollers. The production of color separation plates that guarantee accurate registration is significantly simpler than soft color separation plates. The production of rubber color separation plates, such as those that have hitherto had to be used in Sammel printing, is very expensive and, nevertheless, does not give a high degree of registration accuracy. By the use of hard color separation plates it is also possible to ink the smallest isolated areas of different colors. This is because, compared to rubber color separation plates, an isolated, smallest ink surface can be formed which is not displaced on contact with a rigid plate cylinder as is the case with rubber color separation plates.

Furthermore, each rubber cylinder receives all the ink by 2
Helpful for dividing. 2 like this for each ink
Splitting means that each ink deposited on the printing plate from the preceding blanket cylinder is sequentially divided into 1/2 ink film thickness between the printing plate and all the following blanket cylinders (later in the direction of rotation). The same amount of ink is transferred from the printing plate back to all the following blanket cylinders, and by dividing the ink into two parts, the ink applied to the printing plate becomes more uniform. be done.

EXAMPLES The invention will be explained in more detail on the basis of a sheet-fed rotary printing press, but the invention can of course also be used in web-fed rotary printing presses.

The sheets 2 to be printed, fed from a sheet feeding device 1 which feeds sheets in a scaly manner, are transferred in a known manner to a stop drum 3 by means of a conveyor belt (not shown).
It reaches the impression cylinder 6 via. The stop drum 3 and the impression cylinder 6 are equipped with controlled sheet gripping devices of the type known in sheet-fed rotary printing presses.
Since the impression cylinder 6 holds a rubber blanket 7 on its outer periphery, it has an elastic action.

A plate cylinder 9 cooperates with the impression cylinder 6 under pressure. Between the impression cylinder 6 and the forme cylinder 9, the printing medium to be printed, for example the sheet 2, is printed. The printing form cylinder 9 carries on its outer periphery one or more printing plates, for example hard relief plates 10, which are designed in accordance with the printing principle. The letterpress 10 of the printing cylinder 9 is a small rubber cylinder 5; 11; 12;
13 partially fleshed rubber blankets 1
5; 20; 25; 30 are partially inked in multiple colors. Each rubber blanket 15; 20; 2
5;30 is the associated rubber cylinder 5;1
1; 12; color separation rollers 14 assigned to 13;
Receive ink from 16; 17; 18. Each color separation roller 14; 16; 17; 18 has a color separation plate 19;
21; 22; 23 are stretched. Color separation version 1
9; 21; 22; 23 are made of a hard material, such as Nyloprint or metal, and are machined with partially convex plate surfaces in the same way as known soft color separation plates, so that each convex Each printing plate has one inking device 24; 26; 27;
28, the rubber blanket 15 of the rubber cylinder 5; 11; 12;
Handed over at 20;25;30.

The color separation rollers 14; 16; 17; 18 have the same diameter or outer circumference as the following blanket cylinders 5; 11; 12; 13. The plate cylinder 9 and impression cylinder 6 have diameters several times larger than those of the color separation plate roller and blanket cylinder. In the exemplary embodiment shown, the forme and impression cylinders have a diameter three times that of the color separation rollers 14; 16; 17; 18.

Rubber blanket 15; 20 according to the invention;
Rubber cylinder 5; 11; 12; 13 with 25; 30;
Due to this arrangement, ink is transferred from the printing cylinder 9 to the letterpress printing plate 10 in two parts a plurality of times. This means that the letterpress 10 of printing cylinder 9 is all rubber cylinders 5; 11; 1.
This is because they are sequentially rolled by 2;13.

All cylinders, separation rollers and inking units are driven synchronously by one main motor via a common gear transmission in a known manner.

The printed sheets are conveyed by known gripping devices to a delivery device where they are stacked in piles. If the printing mechanism according to the invention is used in a paper web rotary printing press, the printed paper web is fed, for example, to a cross-cutting device, where it is cut into sheets and then fed to a pile-forming device.

[Brief explanation of drawings]

The drawing shows a schematic side view of a sheet-fed rotary printing press for Sammel printing with a printing mechanism according to the invention. 1...Paper feeding device, 2...Sheet paper, 3...Stop drum, 5...Rubber cylinder, 6...Impression cylinder, 7...Rubber blanket, 9...Print cylinder, 10...Letterpress, 11,
12 and 13... Rubber cylinder, 14... Color separation plate roller, 15... Rubber blanket, 16, 17 and 18... Color separation plate roller, 19... Color separation plate, 20...
... rubber blanket, 21, 22 and 23 ... color separation plate, 24 ... inking device, 25 ... rubber blanket, 26, 27 and 28 ... inking device,
30...Rubber blanket.

Claims (1)

[Scope of Claims] 1. A sammel printing mechanism for a rotary printing machine for securities, which includes a printing cylinder on which a printing plate is stretched, an impression cylinder, and a plurality of color separation plates each having a partially convex printing surface. In the type having a roller and an inking device assigned to each color separation plate roller, each color separation plate roller 14; 16 has a hard color separation plate 19; 21; 22; 17; 18 and the plate cylinder 9, a drivable blanket cylinder 5; 11; 12; 1 with a rubber blanket 15; 20; 25; 30 stretched;
3 are provided respectively, and the color separation plate 19;
1; 22; 23 put ink on rubber blanket 1
5; 20; 25; 30, the ink received by the rubber blanket 15; 20; 25;
Rubber blanket 15; 20; 25; 3 on the printing plate
A portion of the ink delivered by plate cylinder 9
another rubber blanket 15 downstream in the direction of rotation;
20; 25; 30; a Sammel printing mechanism for a rotary printing press for securities; 2. A sammel printing mechanism for a rotary printing press according to claim 1, wherein a hard letterpress plate 10 is stretched over the plate cylinder 9.