JPH0453178B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a brush dampening roll device for an offset printing press. Such a brush dampening roll device includes a dip roller immersed in a dampening medium container, a brush roller that absorbs the dampening medium from the roller, and a brush roller that receives the dampening medium from the brush roller and receives the dampening medium from the brush roller. and a vibrator distribution roll which transfers the dampening medium to a dampening form roller, by means of which the dampening medium is then transferred from the dampening form roller to the plate cylinder.

PRIOR ART AND THE PROBLEM TO BE SOLVED BY THE INVENTION All dampening roll systems for offset printing presses, ie also brush dampening rolls, require metering of the amount of water. For example, attempts have been made to use adjustment strips to somewhat deflect the brush roll brushes and thus achieve increased or decreased water transfer. It is also known to influence the water flow by a comb-shaped slide between the ductor roller and the brush roller (fountain and brush roll). However, the application of all these devices did not reach the desired accuracy. Therefore, brush dampening rolls of this type cannot yet be used in so-called commercial printing presses.

These, as well as web offset newsprint presses, also allow certain jobs to not use the full working width of the press, but only a portion of it, thus leaving the wet media in an unused area of the press. The problem is that it shouldn't.

For this reason, a covering slide is used to limit the width of the dampening roll's working area.
have already been used, whereby the dampening medium supplied by the brush roller is returned back into the dampening medium supply container from these width areas where no dampening medium is needed. Similarly, attempts are made to adapt the dampening roll apparatus to the different dampening roll liquid requirements of the individual width areas of sheet-fed or web printing, namely by means of adjustable covering hoods or sheets. Sheet-fed or web printing is already taking place, with different dampening medium requirements for different inks/colors in the individual width areas, use of spot inks in the individual width areas, etc. arises from This is particularly relevant to offset newspaper rotary presses, but also to commercial printing presses. However, this solution is not only expensive to construct, but also quite inaccurate for many applications.

It is therefore an object of the invention to provide a brush dampening roll for an offset printing press, in which the supply of dampening medium to the individual width areas of the printed product is adapted to the respective requirements. Since they can be adjusted with simple means and with great precision, brush dampening rollers can be used with the best advantage for newspaper or commercial offset printing presses.

Means for Solving the Problem This problem is solved in the present invention by dividing the dip roller into two or more parts, which dip rollers have different speeds/revolutions, including zero rotation speed. They can be driven in number by completely separate drives, independently of each other.
This makes it possible to supply different width regions with correspondingly correct amounts of dampening medium by respectively selecting the speed of the associated diplorer parts.

Supply of dampening medium in non-printing areas when the width of the printing paper is less than the overall width of the printing press by stopping the individual diplorer sections, i.e. by reducing the speed to zero. It is possible to stop it completely.

This solution can be realized in practice especially in designs where the drive of the various diproller parts takes place from both ends of the diproller. This suffices if the diproller is divided into only two parts. However, this is insufficient in most practical cases and the dip roller is also divided into four or more parts. Accordingly, in a further development of the present invention, two diproller parts are driven by a central shaft and the remaining diplower parts are driven by a hollow shaft surrounding these central shafts.

Embodiments of the present invention will be described with reference to the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Figures 1 and 2 schematically illustrate a first portion of a brush dampening roll apparatus to which the present invention relates. The brush dampening roll device typically includes a dampening medium container 1, a dip roller 2 immersed therein, a brush roller 3, a vibrator 4, and a dampening form roller 5. from which the dampening medium is then transferred to the plate cylinder 6.

FIG. 1 already shows that the diplorer (in the actual embodiment shown) is divided into four individual parts, which are divided into three parts:
As will be explained in more detail with reference to the figures, they can be driven independently of each other at different rotational speeds (including zero rotational speed) by completely separate and independent drives.

Figure 1 shows the day roller part (2) on the right side.
c, 2d) is driven by the central axis 7
and the gear motor 8, and the drive of the other dip roller part on the right half is
It has already been shown that this takes place via a hollow shaft 9 surrounding the central shaft 7 and another gear motor.
Exactly the same drive arrangement/device is also present on the left side of FIG. 1, but is not shown. The driving of the individual diproller parts therefore takes place from the two ends of the diproller.

Further details of the driving of the individual diplorer parts can be understood from FIG. 3, in which each part has the same reference numerals as in FIGS. 1 and 2. The central shaft 7 located on the right side is a gear motor 8
and the dip roller portion 2c
to drive. The dip roller part 2d is driven by a hollow shaft 9 surrounding the central shaft 7, and the shaft 9 is driven by a gear motor 10. Similarly, the dip roller part 2b of the left part of the dip roller is driven via a central shaft 11 from a gear motor 12, and the drive of the dip roller part 2a is via a hollow shaft 13 surrounding the central shaft 11 and from a gear motor 14. It will be done.

The central axes 7 and 11 together with the dip roller parts 2b and 2c form two continuous axes which are supported in bearings 16 in the frame 15 of the dampening roll and in bearings 19 on the central support 20. and are rotatable concentrically with respect to each other. The dip roller parts 2a and 2d are themselves rotatably supported by bearings 17 and 18 on shafts 7 and 11. All required seals are specified in 21.

[Brief explanation of the drawing]

FIG. 1 shows in perspective a portion of the brush dampening roll relevant to the present invention. FIG. 2 dampens a partial side cross-section of the portion of the dampening roll shown in FIG. FIG. 3 shows a longitudinal section of the drive element for the dip roller and its individual parts. By way of example only, the figure shows four individual sections, which are drawn shorter than their actual length for drafting reasons. 1... dampening medium container, 2... day roller, 3
...Brush roller, 4...Vibrator, 5...
Dampening liquid application roller, 7, 11...center shaft, 9, 1
3...Hollow shaft, 14...Gear motor.

Claims (1)

Claims: 1. A dip roller immersed in a dampening medium container and a brush roller taking over a dampening medium application roll, whereby the dampening medium is applied to the dampening medium. Brush dampening roll device for offset printing presses, in particular web offset newsprint presses or commercial printing presses, which is transferred onto the printing plate cylinder by a roll, the dip roller being divided into two or more parts. in which the parts have a separate drive, whereby all parts 2a
2b can be driven independently of each other at different rotational speeds (including zero rotational speed) by completely separate and independent drives. 2. The brush dampening roll device according to claim 1, wherein the portions 2a to 2d of the dip roller are driven from both ends of the dip roller. 3 Patent in which the two dip roller parts 2b, 2c are driven by central shafts 11, 7 and the remaining dip roller parts 2a, 2d are driven by hollow shafts 13, 9 surrounding these central axes. A brush dampening roll device according to claim 1 or 2.