Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F35/00—Cleaning arrangements or devices
  • B41F35/02—Cleaning arrangements or devices for forme cylinders
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41P—INDEXING SCHEME RELATING TO PRINTING, LINING MACHINES, TYPEWRITERS, AND TO STAMPS
  • B41P2235/00—Cleaning
  • B41P2235/40—Cleaning restricted areas on cylinders

Definitions

• the invention relates to an inking unit of a printing press with a plate cylinder, on the circumference of which a scraper which is adjustable in the axial direction of the plate cylinder can be brought into abutment in order to remove dirt particles adhering there.
• a Dirt particles adhering to a printing unit's inking unit are problematic because they result in corresponding imperfections in the printed image.
• the dirt particles, also called parasites must therefore be removed from the plate cylinder as soon as the printer detects the occurrence of such parasites in the printed image.
• the scraper generally also motorized, is placed against the circumference of the plate cylinder so that it can remove the dirt particles in question.
• a relatively large amount of time is required for the rough positioning of the scraper, it having to be taken into account that print images of inferior quality are produced in the unnecessarily elapsed time, precisely with such parasites, or the print is even waste.
• the invention is therefore based on the object of proposing an inking unit with the features mentioned at the outset, which is distinguished by a noticeably shorter time which elapses between the discovery of such a parasite and its removal by the scraper.
• the invention is characterized in that a controller is provided which controls a motorized presetting of the scraper in the axial direction of the plate cylinder using at least one of the following criteria: a) if a color scanner is present, it sends out output signals via which the scraper is preset at the point at which the greatest color density of the print image in question prevails, b) the scraper moves to a position in the central region of the print image. c) a learning algorithm is provided, by means of which the scraper is preset to the position which the scraper had a: most often in the past.
• Feature a will be used if the print image in question has areas of different color density for the color in question, viewed side by side in the running direction of the machine. It is known from experience that in the case of such printed images in the areas of greater color density there is a greater probability of the occurrence of the parasites and this information known to the color scanner is therefore used for the method according to the invention for presetting the scraper.
• the method according to feature b) will be selected if there is essentially the same color distribution over the sheet width in the inking unit in question, so that the occurrence of the parasites over the sheet width (in the axial direction of the plate cylinder) is approximately equally likely at any point .
• the setting provided here in the central area of the plate cylinder and thus the print image also noticeably minimizes the distances compared to the prior art, where this "parking position" was provided on the edge of the print image.
• the feature c) takes advantage of the knowledge that - provided the same print image is present - the parasites generally occur in the same axial position in many cases and the learning algorithm is used to inform the controller of this position, in which the parasites occur in large numbers and the scraper is preset to this position.
• the presetting according to feature c) via the learning algorithm thus makes use of presets from the past that were either started manually or via the feature a) and / or the feature b).
• Fig. 1 schematically an end view of the essential components of an inking unit according to the invention
• FIG. 1 schematically shows a section of an inking unit of a printing press.
• a rubber cylinder 1 abuts a plate cylinder 2.
• the cylinders rotate in the direction of arrows 3.
• Rollers 4 of a dampening unit and inking rollers lie on the plate cylinder.
• a scraper 5 lies on the circumference of the plate cylinder 2.
• the scraper can via a servomotor 6 in the direction of Arrow 7 are moved along the plate cylinder.
• the scraper sits on a rod or spindle 8 which is held on frame parts 9.
• the axial position of the scraper 5 in the direction of the double arrow 7 is preset according to the inventive method, as explained at the beginning. If the printer now detects the presence of a dirt particle or parasite on the printed image, he only needs to adjust the scraper finely to the position in question and he can then bring the scraper with its tip into contact with the plate cylinder 2 so that the dirt is then removed there. The scraper then moves back again and into its starting position given to it by the control according to the invention.

Landscapes

• Inking, Control Or Cleaning Of Printing Machines (AREA)
• Printing Plates And Materials Therefor (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6391110

Family Applications (1)

Country Status (5)

Families Citing this family (2)

Citations (4)

• 1989
  • 1989-10-09 DE DE3933677A patent/DE3933677A1/de active Granted
  • 1989-10-09 DE DE3943578A patent/DE3943578C2/de not_active Expired - Fee Related
• 1990
  • 1990-10-09 JP JP2515129A patent/JPH07119113B2/ja not_active Expired - Fee Related
  • 1990-10-09 DE DE59009413T patent/DE59009413D1/de not_active Expired - Fee Related
  • 1990-10-09 WO PCT/EP1990/001687 patent/WO1991004860A1/de unknown
  • 1990-10-09 AT AT90119358T patent/ATE125204T1/de not_active IP Right Cessation
  • 1990-10-09 EP EP90119358A patent/EP0422593B1/de not_active Expired - Lifetime

Patent Citations (4)

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