EP0893251A2 - Printing machine comprising a dampening device - Google Patents

Abstract

The dipping roller (105) is in roller-contact with the slip roller (106). Both rollers rotate at a first surface speed. A printer roller (107) rotates at a second surface speed higher than the first surface speed. An intermediate roller (108) is n contact with the slip and printer rollers, and rotates at a third surface speed higher than the first, and less than the second surface speed. The first intermediate roller is rotated by a gear mechanism connected to the damper (102).

Description

The present invention relates to a printing press with a dampening system several slits having nips according to the preamble of Claim 1.

In the printing machines of the prior art, the rollers of the dampening system operated at a speed lower than the speed of the rollers of the printing unit. This difference in speed causes a slip in the Gap of the transition area between the dampening unit and the printing unit, which is subsequently referred to as Slip gap is called. A slip gap, i. H. a gap in which the Contact surfaces of the adjacent rollers are subject to slip in high-speed offset printing machines to apply a dampening solution to the To achieve printing unit rollers in the correct dosage.

Such as B. is shown in Fig. 1, comprises a printing system or a printing press 1st as is known, a dampening unit 2 and printing unit 3. The dampening unit 2 has one Dipping roller 5, which receives dampening solution from a dampening solution reservoir 4. A a slip roller 6, which is referred to below as a slip roller, is in contact with the dip roller 5, and both rollers, namely the dip roller 5 and the slip roller 6 are driven so that they are the same Rotate surface speed (i.e. the surface speed the rollers are identical). By the rotation and the contact of the dip roller 5 and the slip roller 6 together becomes the dampening solution guided by the dip roller 5 transferred to the slip roller 6.

The printing unit 3 comprises a printing unit roller 7, the z. Legs Dampening roller or a bridge roller, which dampening solution on the Plate cylinder or on inking rollers of the printing unit can be transferred. The Printing unit roller 7 is no closer via slip-free nips with subordinate shown rollers of the printing unit 3 brought into contact. Furthermore contacted the Printing unit roller 7, the slip roller 6 and thereby takes over from the slip roller 6 led dampening solution. Then the printing unit roller 7 transfers the dampening solution other elements of the printing unit 3. The printing unit roller 7 is in the way driven to move at a higher surface speed than the slip roller 6 turns. This creates a slip gap 8 in the transition area between the Dampening unit 2 and the printing unit 3 created, via which the printing unit 3 Fountain solution is supplied.

It has been observed that the transfer of fluid occurs through a slip gap deteriorates when the speed ratio between the two in with each other Contacting rollers (e.g. the surface speed of the fast roller in the Ratio to the surface speed of the slow roller) is large. Both previous systems, the speed of the dampening system was increased to the Reduce the speed ratio in the slip gap without reducing the speed the press. However, this speed increase resulted in the Dampening system to further difficulties. For example, at high Too much dampening solution fed to the printing unit at the speeds of the dampening unit become. Furthermore, at high dampening unit speeds, dampening solution can be used Dampening rollers are thrown off, causing an inconsistent supply of Fountain solution results.

The object is achieved by the invention, a printing press with a To create dampening system, which is a good even at high production speeds metered and even supply of dampening solution enables. This task will solved according to the invention by the features of claim 1.

Further features of the invention are contained in the subclaims.

According to the present invention, a printing press has a dampening unit which comprises an immersion roller and a slip roller, both of which are in rolling contact with one another and rotate at a first surface speed V ₁ . A printing unit roller of the printing unit of the printing press rotates at a second surface speed V ₂ , which is greater than the first surface speed V ₁ . Arranged between the dampening unit and the printing unit is a first intermediate roller which is in slip contact with the slip roller and the printing unit roller and rotates at a third surface speed V ₃ which is higher than the first surface speed V ₁ and lower than the second surface speed V ₂ is. The printing unit roller is preferably a dampening solution application roller, which transfers dampening solution to the plate cylinder of the printing unit. However, it can also be a bridge roller known from the prior art, which transfers dampening solution from the dampening unit to one of the inking rollers of the printing unit.

The intermediate roller can either by a dampening system or by a Printing mechanism associated drive mechanism are driven, the necessary regulation of the peripheral speed of the intermediate roller by known geared drive method can take place. The intermediate roller can z. B. are driven independently of the dampening unit and printing unit. It can too several, for example individually driven by appropriate motors Intermediate rolls are used.

The invention is described in the following description of preferred exemplary embodiments Connection in connection with the accompanying drawings explained below.

Fig. 1

eine Druckmaschine des Standes der Technik mit einem Feuchtwerk;

Fig. 2

eine erste Ausführung einer Druckmaschine gemäß vorliegender Erfindung;

Fig. 3

eine zweite Ausführung einer Druckmaschine gemäß vorliegender Erfindung;

Fig. 4a

ein erstes Antriebssystem einer Druckmaschine gemäß vorliegender Erfindung;

Fig. 4b

ein zweites Antriebssystem einer Druckmaschine gemäß vorliegender Erfindung;

Fig 4c

ein drittes Antriebssystem der erfindungsgemäßen Druckmaschine.

Show it:

Fig. 1

a printing machine of the prior art with a dampening unit;

Fig. 2

a first embodiment of a printing press according to the present invention;

Fig. 3

a second embodiment of a printing press according to the present invention;

Fig. 4a

a first drive system of a printing press according to the present invention;

Fig. 4b

a second drive system of a printing press according to the present invention;

Fig. 4c

a third drive system of the printing press according to the invention.

2 shows a first embodiment of a printing press according to the present invention. The printing press 101 comprises a dampening unit 102 and a printing unit 103. The dampening unit 102 comprises at least one dampening unit roller, e.g. B. a plunger roller 105 which receives dampening solution from a dampening solution reservoir 104 by z. B. partially immersed in the dampening solution reservoir 104. The plunger roller 105 is driven by a conventional drive device (not shown) and rotates at a surface _speed V _damp which corresponds to the surface _{speed of} the dampening unit. The dampening unit 102 further comprises a slip roller 106 which contacts the immersion roller 105 in the gap 111. The slip roller 106 is also driven at the surface _speed V _{damp of} the dampening unit 102, e.g. B. by the same drive device that drives the plunger roller 105, or by a separate drive device.

The printing unit 103 further comprises a printing unit roller 107, which further (not shown) elements of the printing unit 103, z. B. contacted a blanket cylinder, an inking roller, etc. of the printing unit in order to supply the dampening solution received from the dampening unit 102 to the printing unit 103. The printing unit roller 107 is driven at a surface speed V _press which corresponds to the surface speed of the printing unit, but which is higher than the surface _speed V _{damp of} the dampening unit 102.

An intermediate roller 108 is between the slip roller 106 and the Printing unit roller 107 arranged. The intermediate roller 108 contacts the slip roller 106 and the printing unit roller 107 and thus forms a first slip gap 109 at the contact point of slip roller 106 and intermediate roller 108, and a second Slip nip 110 at the contact point of intermediate roller 108 and Printing unit roller 107. The dampening solution is removed from the via the first slip gap 109 Slip roller 106 onto intermediate roller 108 and then across the second slip nip 110 transferred from the intermediate roller 108 to the printing unit roller 107.

The intermediate _roller 108 is driven with an intermediate surface speed V _intermed , which is higher than the surface _speed V _{damp of} the dampening unit and lower than the surface _speed V _{press of} the printing unit. For example, as shown in Fig. 4a, the intermediate roller 108 can be driven by selecting a reduction ratio of a gear mechanism 402 coupled to the intermediate roller 108 and the drive device 401 of the dampening unit 102 in such a way that the selected ratio of surface speed (V _damp ) of the slip roller 106 to the surface _speed (V _intermed ) of the intermediate roller (108) is reached. As shown in Fig. 4b as an alternative, the intermediate roller 108 can be connected via the gear mechanism 402 to the drive device 403 of the printing unit 103, the reduction ratio preferably being selected such that the surface speed of the intermediate roller 108 (V _intermed ) is a predetermined fraction of the surface speed V _{press of} the printing unit is. The intermediate roller 108 can, according to the example shown in Fig. 4c also by an independent drive device 404, z. B. driven by an independent motor with an independently controlled surface speed (V _intermed ) in such a way that the desired speed is achieved relative to V _damp and V _press .

Since both slip gaps, namely the first slip gap 109 and the second slip gap 110 are used, the speed ratio in each slip gap of the printing press 101 is reduced without increasing the speed of the dampening unit 102. This can also be expressed as follows: Since V damp <V intermed <V press is follows V intermed / V damp <V press : / V damp , and V press / V intermed <V press / V damp .

Thus, the speed ratio in the first slip gap (V _intermed / V _damp ) and the speed ratio in the second slip gap (V _press / V _intermed ) will always be lower than the speed ratio which can be achieved in a printing press with only a single slip gap ( V _press / V _damp ) exists.

3 shows a further exemplary embodiment of a printing press according to the present invention. As in the first exemplary embodiment, the printing press 201 comprises a dampening unit 102 and a printing unit 103. However, in contrast to the first exemplary embodiment, the intermediate roller 108 (FIG. B. by intermediate rollers 208A and 208B replaced. The intermediate rolls 208A and 208B can be driven in such a way that they only rotate in the first slip gap 109 and in the second slip gap 110 at the same surface speeds as is the case in the first exemplary embodiment. The intermediate rolls 208A and 208B can, however, also be driven in a third slip nip 211 with different surface speeds. This allows an additional reduction in the speed ratio for each slip nip in the printing press to be achieved without _increasing V _damp according to the principles mentioned above.

Here, the same gear mechanisms and / or drive systems as described above can be used in any combination to ensure that the desired surface speeds of the intermediate rolls 208A and 208B are achieved. A third slip gap 211 can therefore be formed, in which the first intermediate roller 208A rotates at a first intermediate speed V _intermed1 and the second intermediate roller 208B at a second intermediate speed V _intermed2 . The following relationship exists between the surface speeds: V damp <V intermed1 ≤ V intermed2 <V press

There is also the possibility that any number of additional slip column can be formed to further increase the speed difference in each slip gap decrease while the difference between the speed of the dampening system and that of the printing unit is maintained or increased. This enables the Increase the speed of the printing unit without the speed of the Need to increase dampening accordingly.

LIST OF REFERENCES

1

Printing machine (Fig. 1)

2nd

Dampening system (Fig. 1)

3rd

Printing unit (Fig. 1)

4th

Fountain solution reservoir (Fig. 1)

5

Dip roller (Fig. 1)

6

Slip roller (Fig. 1)

7

Printing unit roller (Fig. 1)

8th

Slip gap (Fig. 1)

101

Printing unit (Fig. 2)

102

Dampening system (Fig. 2)

103

Printing unit (Fig. 2)

104

Fountain solution reservoir (Fig. 2)

105

Dip roller / dampening roller (Fig. 2)

106

Slip roller (Fig. 2)

107

Printing unit roller (Fig. 2)

108

Intermediate roller (Fig. 2)

109

first slip gap (Fig. 2)

110

second slip gap (Fig. 2)

111

Slip gap (Fig. 2)

201

Printing machine (Fig. 3)

208A

Intermediate roller (Fig. 3)

208B

Intermediate roller (Fig. 3)

211

third slip gap (Fig. 3)

401

Drive device

402

Drive mechanism

403

Drive device

404

independent drive device

Claims (5)

Printing machine with a dampening unit (102), which has an immersion roller (105) and a slip roller (106), the immersion roller (105) being in rolling contact with the slip roller (106) and both at a first surface speed V ₁ , and with a printing unit roller (107), which rotates at a second surface speed V ₂ , which is higher than the first surface speed V ₁ ,
characterized by
an intermediate roller (108; 208A) which is in slip contact with the slip roller (106) and the printing unit roller (107), the intermediate roller (108; 208A) rotating at a third surface speed V ₃ which is higher than that first surface speed V ₁ and less than the second surface speed V ₂ . Printing machine according to claim 1,
characterized,
that the first intermediate roller (108; 208A) is rotated by a gear mechanism (401, 402) coupled to the dampening unit (102). Printing machine according to claim 1,
characterized,
that the first intermediate roller (108; 208A) is rotated by a gear mechanism (403, 403) coupled to the printing unit. Printing machine according to claim 1,
characterized,
that the first intermediate roller (108; 208A) is rotated by an independent drive mechanism (404). Printing machine according to claim 1,
characterized,
in that a further intermediate roller (208B) is provided which contacts the intermediate roller (208A) and is in slip contact with the printing unit roller (107).

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