EP0290775A2 - Sheet-conveying device - Google Patents

Sheet-conveying device Download PDF

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Publication number
EP0290775A2
EP0290775A2 EP88105259A EP88105259A EP0290775A2 EP 0290775 A2 EP0290775 A2 EP 0290775A2 EP 88105259 A EP88105259 A EP 88105259A EP 88105259 A EP88105259 A EP 88105259A EP 0290775 A2 EP0290775 A2 EP 0290775A2
Authority
EP
European Patent Office
Prior art keywords
zone
printing
sheet
cylinder
rubber blanket
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP88105259A
Other languages
German (de)
French (fr)
Other versions
EP0290775A3 (en
Inventor
Claus Dipl.-Ing. Simeth
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Manroland AG
Original Assignee
MAN Roland Druckmaschinen AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by MAN Roland Druckmaschinen AG filed Critical MAN Roland Druckmaschinen AG
Publication of EP0290775A2 publication Critical patent/EP0290775A2/en
Publication of EP0290775A3 publication Critical patent/EP0290775A3/en
Withdrawn legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41F—PRINTING MACHINES OR PRESSES
    • B41F21/00—Devices for conveying sheets through printing apparatus or machines
    • B41F21/10—Combinations of transfer drums and grippers

Definitions

  • the various gripper devices in printing presses serve to pass the sheet to be printed through the printing press in register and either to place it on the delivery stack or to transfer it to a subsequent printing press with register.
  • a prerequisite for a perfect conveying of the sheet through the entire system is an immovable holding of the sheet by the grippers, i. H. even in the worst case, the gripping force of the grippers must be greater than the external forces acting on the sheet during conveying, which in individual cases show considerable differences.
  • the tensile forces on the sheet reach considerable values, in particular when processing strict colors and at high printing speeds. There is a risk that the sheets will stick to the printing form or the rubber blanket and be pulled out of the gripper systems.
  • the tensile force on the sheet is strongest when the leading edge of the sheet just leaves the printing zone and it becomes less the further away the leading edge of the sheet is from the printing zone.
  • the object of the invention is to support the action of the gripper systems in an apparatus of the type mentioned, even in the pressure application zone.
  • a gripper shaft 9 is mounted in the end wall of a printing cylinder 1 of a sheet-fed printing press and carries the gripper systems 2 interacting with gripper supports 3.
  • a blanket cylinder 6 is assigned to the impression cylinder 1, on which a blanket 7 is fastened by means of a blanket tensioning device 8.
  • a zone of increased static friction 4 is seen continuously across its width starting shortly before the printing operation in the surface of the printing cylinder 1 arranges.
  • This zone can also be designed as a bar.
  • the zone or bar 4 is approximately 5 to 20 mm wide and is selected from the material or from its surface quality so that there is a significant difference between the coefficient of friction of the surface of the printing cylinder 1 and this material. In this way, a stretch-limited increase in static friction between the printing cylinder 1 and the sheet 5 during printing can be achieved with the aim of not only transmitting the tensile load acting suddenly on the sheet 5 to the gripper systems 2 of the printing cylinder 1.
  • a lubricious non-stick coating is also provided on the blanket 7, which is made of a plastic with a low coefficient of friction, e.g. consists of polytetrafluoroethylene.
  • the zone of increased static friction or the corresponding bar 4 on the pressure cylinder 1 are shown schematically as a detail in FIG. 2, while the course of the tensile force on the gripper systems 2 is shown over time in FIG. 3.
  • the dashed curve illustrates the reduction in the peak load of the tensile force on the grippers of the gripper systems 2 in the pressure application zone by means of the measures according to the invention.
  • the advantages of the invention are in particular that only low costs arise in order to support the gripper systems 2 in their effect from the beginning, ie even before the static friction comes into effect due to the wrap angle of the sheet 5 on the impression cylinder 1.
  • the sheet 5 from the rubber blanket 7 with reduced peak load when the front edge of the sheet 5 passes through Subtract peak load when the leading edge of the sheet 5 passes through the printing zone, thereby reducing the risk of duplication.
  • the registration accuracy is increased. With the use of pressure, the grippers of the gripper systems 2 are relieved and there is no tensioning of the sheet.

Abstract

In order to support the gripper systems in their action even in the print action zone and in the small contact angle of the sheet at the printing cylinder, a zone of increased static friction (4) is arranged in the surface of the printing cylinder (1) beginning just before the print action area and continuous across its width. In addition, a slip-inducing anti-adhesion coating made of a plastic having a low coefficient of friction is provided in at least the print action zone on the rubber blanket (7) of the rubber blanket cylinder (6). <IMAGE>

Description

Die verschiedenen Greifervorrichtungen bei Druckmaschinen dienen bekanntlich dazu, den zu bedruckenden Bogen passer­haltig durch die Druckmaschine zu führen und ihn entweder auf dem Auslagestapel abzulegen oder einer nachfolgenden Druckmaschine passerhaltig zu übergeben.As is known, the various gripper devices in printing presses serve to pass the sheet to be printed through the printing press in register and either to place it on the delivery stack or to transfer it to a subsequent printing press with register.

Voraussetzung für ein einwandfreies Fördern des Bogens durch die gesamte Anlage ist ein unverschiebliches Festhalten der Bogen durch die Greifer, d. h. die Haltkraft der Greifer muß auch im ungünstigsten Fall größer sein als die auf den Bogen während des Förderns einwirkenden äußeren Kräfte, die im einzelnen beträchtliche Unterschiede aufweisen. Nach dem Durchgang der Bogenvorderkante durch die Druckzone, wenn der Bogen von der Druckform bzw. bei Offsetdruckmaschinen vom Gummituch abgezogen werden muß, erreichen die Zugkräfte auf den Bogen beträchtliche Werte, insbesondere bei Verarbeitung strenger Farben und bei hohen Druckgeschwindigkeiten. Es besteht dabei die Gefahr, daß die Bogen an der Druckform bzw. dem Gummituch haften bleiben und aus den Greifersys­temen herausgezogen werden. Die Zugkraft auf den Bogen ist am stärksten, wenn die Bogenvorderkante die Druckzone gerade verläßt und sie wird umso geringer, je weiter sich die Bogenvorderkante von der Druckzone wieder entfernt.A prerequisite for a perfect conveying of the sheet through the entire system is an immovable holding of the sheet by the grippers, i. H. even in the worst case, the gripping force of the grippers must be greater than the external forces acting on the sheet during conveying, which in individual cases show considerable differences. After the leading edge of the sheet has passed through the printing zone, when the sheet has to be removed from the printing form or, in the case of offset printing machines, from the blanket, the tensile forces on the sheet reach considerable values, in particular when processing strict colors and at high printing speeds. There is a risk that the sheets will stick to the printing form or the rubber blanket and be pulled out of the gripper systems. The tensile force on the sheet is strongest when the leading edge of the sheet just leaves the printing zone and it becomes less the further away the leading edge of the sheet is from the printing zone.

Erst mit größer werdendem Umschlingungswinkel kann sich die Reibung des Bogens auf dem Druckzylinder erhöhen um damit die Greifer in ihrer Wirkung zu unterstützen.Only with increasing wrap angle can the friction of the sheet on the pressure cylinder increase in order to support the grippers in their effect.

Es ist von Nachteil, daß diese unterstützende Wirkung nicht bereits bei geringem Umschlingungswinkel auftritt.It is disadvantageous that this supportive effect does not already occur with a small wrap angle.

Aufgabe der Erfindung ist es, bei einer Vorrichtung ge­nannter Gattung, die Greifersysteme in ihrer Wirkung bereits in der Druckeinsatzzone zu unterstützen.The object of the invention is to support the action of the gripper systems in an apparatus of the type mentioned, even in the pressure application zone.

Gelöst wird diese Aufgabe durch die Merkmale des Kenn­zeichens des ersten Patentanspruches. Weiterbildungen der Erfindung ergeben sich aus den Unteransprüchen.This object is achieved by the features of the characterizing part of the first claim. Further developments of the invention result from the subclaims.

Die Erfindung wird nachfolgend anhand einer Zeichnung in einem Ausführungsbeispiel erläutert.The invention is explained below with reference to a drawing in one embodiment.

Es zeigt:

  • Fig. 1 eine Stirnansicht, teilweise im Schnitt,
  • Fig. 2 den Druckzylinder nach Fig. 1 als Einzelheit, teilweise schematisch,
  • Fig. 3 den prinzipiellen Verlauf der Zugkraft an den Greifern in Abhängigkeit von der Zeit.
It shows:
  • 1 is an end view, partly in section,
  • 2 shows the printing cylinder of FIG. 1 as a detail, partially schematically,
  • Fig. 3 shows the basic course of the tensile force on the grippers as a function of time.

Entsprechend Fig. 1 ist in der Stirnwand eines Druckzylin­ders 1 einer Bogendruckmaschine eine Greiferwelle 9 gela­gert, welche die mit Greiferauflagen 3 zusammenwirkenden Greifersysteme 2 trägt. Dem Druckzylinder 1 ist ein Gummi­tuchzylinder 6 zugeordnet, auf dem mittels einer Gummi­tuchspannvorrichtung 8 ein Gummituch 7 befestigt ist.1, a gripper shaft 9 is mounted in the end wall of a printing cylinder 1 of a sheet-fed printing press and carries the gripper systems 2 interacting with gripper supports 3. A blanket cylinder 6 is assigned to the impression cylinder 1, on which a blanket 7 is fastened by means of a blanket tensioning device 8.

Gemäß der Erfindung ist beginnend kurz vor dem Druckeinsatz in der Oberfläche des Druckzylinders 1 eine Zone erhöhter Haftreibung 4 durchgehend über dessen Breite gesehen ange­ ordnet. Diese Zone kann auch als Leiste ausgebildet sein. Die Zone bzw. Leiste 4 ist ca. 5 bis 20mm breit und ist vom Werkstoff bzw. von ihrer Oberflächenbeschaffenheit so ge­wählt, daß ein signifikanter Unterschied zwischen dem Reibungskoeffizienten der Oberfläche des Druckzylinders 1 und diesem Werkstoff besteht. Auf diese Weise läßt sich eine streckenbegrenzte Erhöhung der Haftreibung zwischen dem Druckzylinder 1 und dem Bogen 5 während des Druckeinsatzes mit dem Ziel erreichen, die hier schlagartig auf den Bogen 5 wirkende Zugbelastung nicht nur ausschließlich auf die Grei­fersysteme 2 des Druckzylinders 1 zu übertragen.According to the invention, a zone of increased static friction 4 is seen continuously across its width starting shortly before the printing operation in the surface of the printing cylinder 1 arranges. This zone can also be designed as a bar. The zone or bar 4 is approximately 5 to 20 mm wide and is selected from the material or from its surface quality so that there is a significant difference between the coefficient of friction of the surface of the printing cylinder 1 and this material. In this way, a stretch-limited increase in static friction between the printing cylinder 1 and the sheet 5 during printing can be achieved with the aim of not only transmitting the tensile load acting suddenly on the sheet 5 to the gripper systems 2 of the printing cylinder 1.

Um die Haftreibung zwischen dem Gummituch 7 und dem Bogen 5 in der Druckeinsatzzone zu vermindern, ist außerdem eine gleitfähige Antihaft-Beschichtung auf dem Gummituch 7 vorge­sehen, die aus einem Kunststoff mit geringem Reibungskoeffi­zienten, z.B. aus Polytetrafluoräthylen besteht.In order to reduce the static friction between the blanket 7 and the sheet 5 in the printing zone, a lubricious non-stick coating is also provided on the blanket 7, which is made of a plastic with a low coefficient of friction, e.g. consists of polytetrafluoroethylene.

Die Zone erhöhter Haftreibung bzw. die entsprechende Leiste 4 am Druckzylinder 1 sind als Einzelheit schematisch in der Fig. 2 dargestellt, während der Verlauf der Zugkraft an den Greifersystemen 2, über die Zeit in Fig. 3 dargestellt ist. Die gestrichelte Kurve verdeutlicht dabei den Abbau der Spitzenlast der Zugkraft an den Greifern der Greifersysteme 2 in der Druckeinsatzzone mittels der erfindungsgemäßen Maß­nahmen.The zone of increased static friction or the corresponding bar 4 on the pressure cylinder 1 are shown schematically as a detail in FIG. 2, while the course of the tensile force on the gripper systems 2 is shown over time in FIG. 3. The dashed curve illustrates the reduction in the peak load of the tensile force on the grippers of the gripper systems 2 in the pressure application zone by means of the measures according to the invention.

Die Vorteile der Erfindung bestehen insbesondere darin, daß nur geringe Kosten entstehen, um die Greifersysteme 2 von Anfang an in ihrer Wirkung zu unterstützen, d. h. bereits bevor die Haftreibung durch den Umschlingungswinkels des Bogens 5 am Druckzylinder 1 zur Wirkung kommt. Auf diese Weise wird der Bogen 5 vom Gummituch 7 mit abgebauter Spitzenlast bei Durchgang der Vorderkante des Bogens 5 durch Spitzenlast bei Durchgang der Vorderkante des Bogens 5 durch die Druckzone abgezogen, wodurch die Gefahr eines Doublie­rens verringert wird. Außerdem wird die Passergenauigkeit erhöht. Mit Druckeinsatz werden die Greifer der Greifer­systeme 2 entlastet und es tritt keine Verspannung des Bogens auf.The advantages of the invention are in particular that only low costs arise in order to support the gripper systems 2 in their effect from the beginning, ie even before the static friction comes into effect due to the wrap angle of the sheet 5 on the impression cylinder 1. In this way, the sheet 5 from the rubber blanket 7 with reduced peak load when the front edge of the sheet 5 passes through Subtract peak load when the leading edge of the sheet 5 passes through the printing zone, thereby reducing the risk of duplication. In addition, the registration accuracy is increased. With the use of pressure, the grippers of the gripper systems 2 are relieved and there is no tensioning of the sheet.

BezugszeichenlisteReference symbol list

  • 1 Druckzylinder1 impression cylinder
  • 2 Greifersysteme2 gripper systems
  • 3 Greiferauflage3 gripper pad
  • 4 Zone erhöhter Haftreibung bzw. entsprechende Leiste4 zone of increased static friction or corresponding bar
  • 5 Bogen5 sheets
  • 6 Gummituchzylinder6 blanket cylinders
  • 7 Gummituch7 rubber blanket
  • 8 Gummituchspannvorrichtung8 blanket tensioning device
  • 9 Greiferwelle9 gripper shaft

Claims (3)

1.) Vorrichtung zum Fördern von Bogen durch die Druckzone von Zylindern, insbesondere Gummituch- und Druckzylin­der, einer Bogendruckmaschine mittels Greifersystemen, dadurch gekennzeichnet, daß beginnend kurz vor dem Druckeinsatz eine Zone er­höhter Haftreibung (4) in der Oberfläche des Druckzy­linders (1) über dessen Breite gesehen durchgehend angeordnet ist.1.) Device for conveying sheets through the printing zone of cylinders, in particular blanket and impression cylinders, a sheet printing machine by means of gripper systems, characterized in that starting shortly before printing, a zone of increased static friction (4) in the surface of the printing cylinder (1) seen the width is arranged continuously. 2.) Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß als Zone erhöhter Haftreibung (4) eine Leiste im Druckzylinder (1) vorgesehen ist.2.) Device according to claim 1, characterized in that a strip in the pressure cylinder (1) is provided as a zone of increased static friction (4). 3.) Vorrichtung nach Anspruch 1 und 2, dadurch gekennzeichnet, daß auf dem Gummituch (7) des Gummituchzylinders (6) mindestens in der Druckeinsatzzone eine gleitfähige Antihaft-Beschichtung aus einem Kunststoff mit geringem Reibungskoeffizienten vorgesehen ist.3.) Device according to claim 1 and 2, characterized in that on the rubber blanket (7) of the rubber blanket cylinder (6) at least in the printing zone a lubricious non-stick coating made of a plastic with a low coefficient of friction is provided.
EP88105259A 1987-05-14 1988-03-31 Sheet-conveying device Withdrawn EP0290775A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3716160 1987-05-14
DE3716160 1987-05-14

Publications (2)

Publication Number Publication Date
EP0290775A2 true EP0290775A2 (en) 1988-11-17
EP0290775A3 EP0290775A3 (en) 1990-02-14

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Application Number Title Priority Date Filing Date
EP88105259A Withdrawn EP0290775A3 (en) 1987-05-14 1988-03-31 Sheet-conveying device

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007010481A1 (en) * 2007-03-03 2008-09-04 Koenig & Bauer Aktiengesellschaft Sheet-fed rotary printing machine comprises a pressing rising curve with a starting line lying in the region of the printing cylinder with grippers lying on the cylinder
DE102010028698A1 (en) * 2010-05-06 2011-11-10 Manroland Ag Sheet guide device e.g. storage drum, for use as e.g. feeder, in e.g. sheet fed press, has guide surface for guiding electrical charged printed sheets, where guide surface is provided with smooth and rough portions with different roughness

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH387076A (en) * 1959-04-23 1965-01-31 Miehle Goss Dexter Inc Sheet gripping device for printing and similar machines
CH491744A (en) * 1968-09-25 1970-06-15 Maschf Augsburg Nuernberg Ag Grippers for printing machines
DE3041056A1 (en) * 1980-02-29 1981-09-10 VEB Kombinat Polygraph "Werner Lamberz" Leipzig, DDR 7050 Leipzig Paper sheet feed installation - has sheet grip holding surface and sheet grip stop working together and fitted with patterned sheet grip holding surface
EP0151386A2 (en) * 1984-02-04 1985-08-14 M.A.N.-ROLAND Druckmaschinen Aktiengesellschaft Impression cylinder for a sheet-fed offset-type rotary

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH387076A (en) * 1959-04-23 1965-01-31 Miehle Goss Dexter Inc Sheet gripping device for printing and similar machines
CH491744A (en) * 1968-09-25 1970-06-15 Maschf Augsburg Nuernberg Ag Grippers for printing machines
DE3041056A1 (en) * 1980-02-29 1981-09-10 VEB Kombinat Polygraph "Werner Lamberz" Leipzig, DDR 7050 Leipzig Paper sheet feed installation - has sheet grip holding surface and sheet grip stop working together and fitted with patterned sheet grip holding surface
EP0151386A2 (en) * 1984-02-04 1985-08-14 M.A.N.-ROLAND Druckmaschinen Aktiengesellschaft Impression cylinder for a sheet-fed offset-type rotary

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007010481A1 (en) * 2007-03-03 2008-09-04 Koenig & Bauer Aktiengesellschaft Sheet-fed rotary printing machine comprises a pressing rising curve with a starting line lying in the region of the printing cylinder with grippers lying on the cylinder
DE102007010481B4 (en) * 2007-03-03 2018-12-20 Koenig & Bauer Ag Sheet-
DE102010028698A1 (en) * 2010-05-06 2011-11-10 Manroland Ag Sheet guide device e.g. storage drum, for use as e.g. feeder, in e.g. sheet fed press, has guide surface for guiding electrical charged printed sheets, where guide surface is provided with smooth and rough portions with different roughness

Also Published As

Publication number Publication date
EP0290775A3 (en) 1990-02-14

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