DE4431646A1 - Dosing roller on a dampening unit of an offset rotary printing press - Google Patents

Description

The invention relates to a metering roller for a Film dampening system of an offset rotary printing press according to the preamble of the claim.

The DT 20 54 678 is a dampening unit for one lithographic printing machine with at least one Fountain solution application roller known, by means of which the Fountain solution can be applied to a plate cylinder and one upstream of the dampening solution application roller Roll or dampening solution become known. It is the metering roller opposite the dampening solution applicator roller or the dampening solution for the purpose of dampening tiltable, the diameter at the ends of the Metering roller is larger than in its central area.

A disadvantage of this dampening system, however, is that the once set values of the dampening solution metering for a same print job later reproducible only with great effort, being a lot Waste is generated to the optimum Find out dampening solution dosage.

The invention has for its object a Dosing roller to create a dampening system, the  Dampening solution metering repeatable depending on the print order is.

According to the invention, this object is achieved by the features of the characterizing part of the claim.

The invention in particular the following Advantages achieved: due to the storage of the data of the Dampening solution metering of each metering roller of the dampening unit each print job can be combined into one any time with the same print quality and without repeated loss of time or waste will.

The invention is based on one Embodiment explained in more detail. The associated Drawing shows a schematic side view of a Dampening system with presentation of process-necessary Adjustment and control devices.

A dampening unit comprises a co-operating with a plate cylinder 1 dampening form roller 2, a 3 and a Feuchtmittelduktor placed against the metering roller 3 Feuchtmittelduktor. 4 While the dampening solution 3 is mounted fixed to the side frame via its axle journals 6 , the metering roller 4 is mounted in levers 7 which can be pivoted about the axis journals 6 of the dampening solution 3 and can be rotated by eccentric bushings 8 in their spacing a between the axle journals 6 of the dampening solution 3 and the axle journals 9 the metering roller 4 can be adjusted. For this purpose, the sleeve 8 is positively connected to a first end of a lever 11 , while a second end of the lever 11 is connected in an articulated manner to a motor-gear unit 12 with an integrated position indicator or potentiometer 13 . The motor-gear unit 12 is articulated between an end of the lever 7 remote from the dampening medium and said lever 11 . The dampening solution duct 3 is immersed in a dampening solution container 15 . By actuating a motor-gear unit 16 with an integrated position indicator or potentiometer 17 , which is articulated between the end 7 of the lever 7 carrying the metering roller 4 and a side frame 14, with an integrated position indicator or potentiometer 17 , each lever 7 can be pivoted and thus the metering roller 4 can be tilted with respect to the dampening unit 3 . The diameter of both ends of the metering roller 4 can be larger than the diameter of the central region of the metering roller 4 .

Each of the parts 6 to 9 , 11 to 14 and 16 , 17 , 19 and 21 is provided twice, ie separately for each end face of the dampening solution 3 or the metering roller 4 , but only shown once in the drawing and labeled only once. Each potentiometer 13 ; 17 of the motor gear units 12 ; 16 is for the purpose of position feedback with a z. B. in the machine control room computer 18 connected, while the computer 18 with each motor-gear unit 12 ; 16 via an amplifier 19 ; 21 communicates. A strip-shaped, the surface of Feuchtmittelduktors 3 in the axially parallel direction scanning dampening thickness control device 22 is connected to the computer 18 and its memory 23 and passes information about the data transferred from the metering roller 4 to the dampening form roller 2 by means of Feuchtmittelduktors 3 moisturizing agent quantity. The computer 18 is also connected to a higher-level controller or keyboard 24 for the purpose of entering control commands and to a monitor 26 . Expediently, however, a plurality of dampening agent thickness control devices 22 spaced apart from one another in the axis-parallel direction of the dampening solution duct 3 are provided.

Acquisition of the measured values when setting a metering roller takes place as follows: the distance a and thus the contact pressure of the metering roller 4 on the dampening solution 3 is preset according to the printing requirements by means of the keyboard 24 . Likewise, a different amount of dampening solution over the length of the dampening solution duct 3 can be preset by means of the motor drive unit 16 due to the separate inclination of the levers 7 . The dampening solution thickness control devices 22 , which are arranged in the axis-parallel direction to the dampening solution duct 3 , transmit the measurement results to the computer 18 , the actual values being compared with the target values on the monitor 26 and, if necessary, a correction being able to be initiated using the keyboard 18 . Once the setpoint values for the amount of dampening solution have been reached, they are saved and the amount of dampening solution is regulated. The stored dampening solution values per print job can be called up at any time from the memory 23 of the computer 18 for repeat jobs and used for metering the amount of dampening solution.

Reference list

1 plate cylinder
2 dampening roller
3 dampening solution
4 metering roller
5 -
6 axle journals ( 3 )
7 levers ( 3 , 4 )
8 rifle, eccentric ( 9 )
9 journal ( 4 )
10 -
11 levers
12 Motor gear unit
13 potentiometers ( 12 )
14 side frame
15 dampening solution tank
16 Motor gear unit
17 potentiometers ( 16 )
18 computers
19 amplifiers ( 12 )
20 -
21 amplifiers ( 16 )
22 Dampening solution thickness control device
23 stores ( 18 )
24 keyboard ( 18 )
25 -
26 monitor ( 18 )
a distance ( 6 , 9 )

Claims (1)

Dosing roller ( 4 ) for a dampening unit ( 2 ; 3 ; 4 ; 14 ) of an offset rotary printing machine, according to which the dosing roller ( 4 ) can be pressed against a dampening solution ductor ( 3 ) and tilted, characterized in that the pressing and inclination of the dosing roller ( 4 ) Corresponding to the dampening solution thickness detected by dampening solution thickness control devices ( 22 ), it is checked that the respective position of the metering roller ( 4 ) set by a motor-gear unit ( 12 ; 16 ) is detected by a position indicator ( 13 ; 17 ) and is ready to be called up in a memory ( 23 ) of a computer ( 18 ) is recorded.