DE2052806A1 - Inking unit for printing machines - Google Patents

Description

Inking unit for printing machines The invention relates to an inking unit for Printing machines consisting of ductor roller, transfer roller and inking roller.

When the color is applied to the forme cylinder, it remains on the application rollers a color relief, which may be noticeable in the print image in a disturbing way.

Since then, attempts have been made to avoid this disruption in that the forme cylinder many, relatively small in diameter applicator rollers are assigned with a Number of distribution cylinders work together so that the color relief is supplied with the necessary The amount of paint is largely leveled. A sufficient distribution of the color can, however can only be achieved with a large number of rollers involved.

All previously known inking units are constructed in such a way that only the amount of ink is supplied, which is passed on from the forme cylinder to the printing material. When transferring the color can be, for example, half the film thickness in the color transfer areas the application roller remain. In this case, the color relief must pass through the distribution rollers leveled and the paint film by feeding of color to the one you want Thickness to be added.

The German patent specification 1 207 940 shows a type of construction in which there is only one application roller, which takes its color requirements directly from the Ink reservoir refers. As the only way to control the thickness of the color film on the application roller, the gap between it and the ink reservoir is used. It is doubtful whether this is sufficient for color control in any case. Also build Considerable hydrodynamic pressures arise at high circumferential speeds.

A similar inking unit is described in German patent specification 1,266,315 shown. Here, too, it is proposed that the color film be dimensioned in a single gap. It is questionable whether this device will prove itself in practice because it is subject to high wear the inking roller is to be expected because of the counter-rotating movement of the inking roller 3 is.

In the German patent 1 176 674 is an inking unit with a Treated single application roller, which is colored by a feed roller and associated with a number of ink spreading rollers. The coming back The color relief remaining on the applicator roller is leveled by distribution rollers and doctored off a number of these distribution rollers. The measure, a relatively thin one Influencing the color film like the returning color relief does not seem appropriate, because experience has shown that this is the case does not lead to success. When working with poor color guidance, the returning film is so thin that it is not can be further split at will.

The invention assumes that rather thick films split at will and can be equalized.

The object of the invention is based on the object of an inking unit to create that offers the forme cylinder a uniform color film that with a smaller number of application and distribution rollers and still one has little wear and tear, which is spatially very small, even for a very high print quality is suitable in which few gaps occur, and in which even with a small amount of paint required, the paint only lingers for a short time.

The object is achieved in that the form cylinder on the inking roller Color relief left behind largely due to a multiple of the amount of color required covered or erased and the excess color thickness by a number of axially moving, squeegee-doctored distribution rollers are split off, the Differences in thickness are also compensated for by lateral rubbing by friction rollers will.

The principle on which the invention is based therefore consists in that To "drown" color relief in color and the resulting too thick Reduce the color film by repeated splitting and reduce the differences in thickness equalize simultaneous rubbing.

For example, a color relief is graded like loo to 50. This is done by the paint box Color of three times the thickness fed to the applicator cylinder so that the thicknesses behave like 400 to 350.

Subsequent splitting in a first stage makes the difference 200: 175, which is reduced to 190: 180 by simultaneous rubbing. In the second Step 50:50 is also assumed, so that thicknesses of 95 9o arise, which are brought to almost the same height by simultaneous rubbing.

An embodiment is shown in the drawing and will explained in more detail below.

The drawing shows a schematic front view of an inking unit.

A part of a forme cylinder is shown which has the reference symbol 1 has. With this is an inking roller 2 in rolling contact, which consists of a Ink fountain 3 via a ductor roller 4 and through transfer rollers 5 and 6 with ink is supplied. The color is supplied to such an extent that a color film is created on the applicator roller 2 by multiples of the required thickness arises. On the circumference of the inking roller 2 are in the direction of rotation after the transfer roller 6 distribution rollers 7 and 8 arranged. At the points of contact of these rollers with the Inking roller 2 occurs color splitting and distribution. The ones from the distribution rollers 7 and 8 picked up paint is doctored 9 and 10 and one is not shown collecting container supplied.

/ Claim

Claims (1)

Claim inking unit for printing machines consisting of ductor roller, Transfer rollers and inking roller, characterized in that the forme cylinder (1) Paint relief left on the inking roller (2) by a multiple the required amount of paint largely covered or erased and the excess Ink thickness through a number of axially moved, doctored blades (9, 10) Distribution rollers (7, 8) are split off, the differences in thickness also being due to the side Rubbing can be compensated for by friction rollers (7, 8).