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GB2034250A - An inking and Moistening Mechanism for a Rotary Offset Printing Press - Google Patents

An inking and Moistening Mechanism for a Rotary Offset Printing Press Download PDF

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Publication number
GB2034250A
GB2034250A GB7937093A GB7937093A GB2034250A GB 2034250 A GB2034250 A GB 2034250A GB 7937093 A GB7937093 A GB 7937093A GB 7937093 A GB7937093 A GB 7937093A GB 2034250 A GB2034250 A GB 2034250A
Authority
GB
United Kingdom
Prior art keywords
roller
ink
inking
moistening
rubbing
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.)
Granted
Application number
GB7937093A
Other versions
GB2034250B (en
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.)
Rotaprint GmbH
Original Assignee
Rotaprint GmbH
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 Rotaprint GmbH filed Critical Rotaprint GmbH
Publication of GB2034250A publication Critical patent/GB2034250A/en
Application granted granted Critical
Publication of GB2034250B publication Critical patent/GB2034250B/en
Expired legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41FPRINTING MACHINES OR PRESSES
    • B41F7/00Rotary lithographic machines
    • B41F7/20Details
    • B41F7/24Damping devices
    • B41F7/36Inking-rollers serving also to apply ink repellants
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41FPRINTING MACHINES OR PRESSES
    • B41F31/00Inking arrangements or devices
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41LAPPARATUS OR DEVICES FOR MANIFOLDING, DUPLICATING OR PRINTING FOR OFFICE OR OTHER COMMERCIAL PURPOSES; ADDRESSING MACHINES OR LIKE SERIES-PRINTING MACHINES
    • B41L25/00Devices for damping printing surfaces, e.g. moistening printing surfaces in connection with lithographic printing
    • B41L25/02Devices for damping printing surfaces, e.g. moistening printing surfaces in connection with lithographic printing using friction rollers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41LAPPARATUS OR DEVICES FOR MANIFOLDING, DUPLICATING OR PRINTING FOR OFFICE OR OTHER COMMERCIAL PURPOSES; ADDRESSING MACHINES OR LIKE SERIES-PRINTING MACHINES
    • B41L27/00Inking arrangements or devices
    • B41L27/04Ducts, containers, or supply devices or ink-level control devices
    • B41L27/12Feed or duct rollers

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Inking, Control Or Cleaning Of Printing Machines (AREA)
  • Rotary Presses (AREA)

Abstract

An inking and moistening mechanism for a small rotary offset printing press has an inking mechanism acting on a stereo cylinder 6 and consisting of an ink-duct roller 1, an ink-lifting roller 2, an intermediate roller 3 and a rubbing roller 4 operating on the ink-applying roller 5 of the stereo cylinder 6, an ink- profile smoothing system in the form of one or more pairs of rider rollers 11, 11' and, optionally, a plurality of polishing rollers 16, this system being arranged downstream of the rubbing roller 4 in the direction of rotation of the ink-applying roller 5 and operates on this roller, and with a moistening mechanism, which likewise acts on the stereo cylinder 6 and comprises a moisture duct roller 12, a metering roller 13 rolling thereon, a moisture- applying roller 14 and a moistening- means rubbing roller 15 acting on the moisture-applying roller 14. The moisture-applying roller of the stereo cylinder is arranged to roll between the moisture-duct roller and the rubbing roller of the moistening means, and this latter roller is arranged in the vicinity of the, or the most downstream, pair of rider rollers of the inking mechanism. When cleaning the system, the inking and moistening mechanisms may be interconnected by moving rider roller 11' to the position shown in dotted lines. <IMAGE>

Description

SPECIFICATION An Inking and Moistening Mechanism for a Rotary Offset Printing Press The present invention relates to an inking and moistening mechanism for a rotary offset printing press.
In connection with the quality of inking mechanisms hitherto used, the standard literature has is that a higher quality of printing can be achieved by increasing the number of application rollers. Consequently, printing presses for meeting high quality requirements have hitherto always incorporated a fairly large number of application rollers on the stereo cylinder. In the normal inking mechanisms, the application rollers have to perform the function of smoothing the ink profile on the printing plate, since as a rule each application roller moves many times over the plate during each printing run, and an inking profile is formed on each application roller during each revolution thereof, which profile is not fully smoothed out until the following rotation and the next stage of contact between the application rollers and the plate.Thus, during the following contact phase, the plate may not have a smoothed film of ink.
It follows from this that the majority of application rollers make good the defects during inking of the plate by means of other application rollers, i.e. they carry out ink-profile smoothing operations on the plate.
In this connection it is to be noted that what are called front-load inking mechanisms are superior to rear-load inking mechanisms. In a front-load inking mechanism, the main flow of ink is passed to the first ink-applying rollers that are the first to touch the plate in the direction of rotation of the stereo cylinder, and the following ink-applying rollers carry out ink-profile smoothing operations on the plate, i.e. they deliver ink to the plate at those zones where the layer of ink is too thin, or they remove ink when the layer of ink is too thick, so that a layer of ink of uniform thickness is created.In a rear-load inking mechanism, the last ink-applying rollers are not able to perform the ink-profile smoothing operations in the best possible manner, since they guide the main flow of ink, and the following position provides the contact between the ink applying roller and the stereo cylinder.
It follows from the foregoing that high quality printing can generally be obtained only when a plurality of application rollers are used. However, this arrangement suffers from the disadvantage that the cost of the printing press is increased since each additional roller is accompanied by increased design and operating costs.
Furthermore the printing press is rendered more difficult of access with each additional roller, i.e.
maintenance costs become higher in the case of such printing presses.
Our Patent Application No. 25526/78 particularly describes two constructions of moistening and inking mechanisms in the first of which the inking and moistening units each act on the ink-applying roller by way of an associated rubbing roller, and, between the said rubbing rollers, an ink-profile smoothing system acts on the ink-applying roller, this system being constituted by a plurality of (three to six) pairs of rider rollers. In the second construction, the moistening unit does not act on the said rubbing rollers on the ink-applying roller, but directly on the stereo cylinder. In other words, an inksupplying moisture-applying roller is located forwardly of the single ink-applying roller of the inking mechanism (alcohol mostening unit) in the direction of rotation of the stereo cylinder.In this case, at least one pair of rider rollers are located on the ink-supplying and moisture-applying roller.
In the first construction of the inking and moistening mechanism of the earlier Application, the ink-applying roller is contacted, in the subsequent position, by a rubbing roller which in addition to transmitting ink also transmits a film of moisture on to the film-applying roller. In the second form of construction, on which the present invention is based, only the moistening unit separated from the inking unit and comprising the ink-applying roller transmits the ink to the image zones of the plate. The last roller of the moisture-applying mechanism acts directly on the stereo cylinder as a moisture-applying roller and in addition as the ink-profile smoothing roller disposed forwardly of the ink-applying roller.
The first form of construction in accordance with the earlier Application is of simpler design than that of the second form of construction, the latter being more advantageous when a high press capacity is required, since the greater number of parts permits an extended tolerance in the ink/water balance at high printing speeds.
Furthermore, a separate moistening operation is inherently better, since this leads to a reduced proportion of emulsified ink.
The present invention is concerned with improvements in the said second construction.
According to the present invention there is provided a inking and moistening mechanism for a small rotary offset printing press incorporating an inking mechanism which acts on a stereo cylinder and which includes an ink-duct roller an ink-lifting roller, an intermediate roller and a rubbing roller operating on an ink-applying roller for the stereo cylinder, an ink-profile smoothing system having at least one pair of rider rollers which system is arranged downstream of the rubbing roller in the direction of rotation of the ink-applying roller and operates on the inkapplying rolier, and a moistening mechanism, which acts on the stereo cylinder and comprises a moisture duct roller, a metering roller rolling thereon, a moisture-applying roller and a moistening-means rubbing roller acting on the moisture-applying roller, said moisture-applying roller being arranged between and in rolling contact with, a moisture-duct roller and the rubbing roller of the moistening-means, and this latter roller being arranged adjacent said one pair of rider rollers or as the case may be the most downstream pair of rider rollers in the direction of rotation of the ink-applying roller.
The invention will now be described in more detail with reference, by way of example, to the accompanying drawings in which Figures 1 and 2 are respectively diagrammatic side views of two constructions according to the invention.
In the construction illustrated in Figure 1 of the drawings, the rubber-cloth cylinder and the counter-pressure cylinder of the offset printing machine are omitted from this Figure, since only the stereo cylinder, carrying the reference numeral 6, is of interest in the present context.
The construction shown in Figure 1 comprises an ink-duct roller 1, from which the ink-lifting roller 2 intermittently removes a strip of ink by virtue of its being arranged to carry out a swinging movement, so as to transfer the strip to an intermediate roller 3. The strip of ink is transferred from this intermediate roller 3 to a rubbing roller 4 of the inking unit, which latter roller swings axially to and fro while it is rotating.
The rubbing roller 4, as seen in the direction of rotation of the ink-applying roller 5, is fitted immediately downstream of the stereo cylinder.
Downstream of the roller 4, in the direction of rotation of the application roller 5, a number of pairs of rider rollers, 7, 7' to 11, 11' are mounted on the application roller. These pairs of rider rollers are located in a common saddle which imparts a uniform rubbing movement to all the pairs of rider rollers.
At the side of the application roller 5 opposite the rider roller 4 but spaced from roller 5, a rubbing roller 1 5 of a moistening unit is provided near the pair of rider rollers 11, 1 1'. The moistening unit is in fact generally likewise covered with ink as far as the moisture-duct roller 12, but its main function is to apply the moistening agent. With the aid of the moistureduct roller 12, the moistening unit picks up the moistening agent from a container and transfers it to the moisture-applying roller 14, the quantity of the moistening agent being determined by a metering roller 13 which rolls against the moisture-duct roller 12.
In the direction of rotation of the stereo cylinder 6, the moisture-applying roller 14 is located directly forwardly of the ink-applying roller 5 and rolls on the stereo cylinder 6, the rubbing roller 1 5 acting only on the moistureapplying roller 14 during the normal printing operation.As explained above, the rubbing roller 1 5 is also permanently spaced from the inkapplying roller 5, but at the same time it is so close to the pair of rider rollers 11, 11' that, for the cleaning and inking-in operations, and at the beginning and end of the printing work, the inking unit and the moistening unit can be interconnected by swinging the pair of rider rollers 11, 11' about the shaft of the roller 11 towards the rubbing roller 15, so that the rider roller 11' establishes connection with the rubbing roller 1 5. When printing begins, the moistening unit is inked up by way of this connection and when printing ends, the entire printing mechanism is thereby cleaned again.
Figure 2 illustrates an alternative form of construction, wherein only the last pair of rider rollers 11, 11' in the arrangement of Figure 1 is retained, the other rider rollers being replaced by simple polishing rollers 16, and wherein further polishing rollers 20 are provided on the moisture applying roller 20. In this printing press the watermetering setting is no longer very critical for the various printing requirements, i.e. despite different operating conditions, it is possible to use a single "universal" water-metering setting, using an excess of water. Thus to a large extent, continual adjustment of the water-metering means to suit each specific printing operation is no longer required.
The retention of the rider rollers 11, 11' permits the cleaning and inking-in connection with the moistening unit, as described in relation to Figure 1.
The polishing rollers 20 are provided on the moisture-applying roller 14 at the side thereof remote from the stereo cylinder 6. These polishing rollers are able to smooth out slight waviness in the ink possibly caused by the "universal" water-metering system.
In the two illustrated embodiments, the ink and moisture applying rollers 5 and 14 are both made of the same material; they are of known construction and are accommodated in like bearings, so that the rollers and the bearings are interchangeable. The same applies as regards the ink and moisture rubbing rollers 4 and 1 5 respectively, rotating in the opposite direction, which have exactly the same dimensions, drives and bearings. This is of considerable importance to the user of the printing press as regards the acquisition and storing of replacements.
In the first embodiment, the five pairs of rider rollers used in the inking system are mounted in a common saddle and in bearings of similar construction. The entire roller saddle executes a rubbing movement which is thus common to all the pairs of rider rollers, and this rubbing movement is counter to that of the rubbing roller 4. The rubbing movement of the rider-roller saddle on the other hand is in the same direction as that of the rubbing roller 1 5, and this is necessary for the time during which the cleaning and inking-in connection is established. As regards the rubbing movement, one of the roller saddles is driven by the moisture-rubbing roller 1 5 so as to spread the ink film over the inkapplying roller in the axial direction. However, this drive only concerns the rubbing movement, since the rotary drive derives from the friction set up by the application roller. The same mode of operation applies as regards the polishing rollers 16 with the pair of rider rollers 11, 11' in the second construction.
The container roller, the ink and moisture rubbing rollers as well as the five rider rollers are covered with hard rubber or a hard plastics material having the same characteristics.
The ink-applying roller is driven directly by the stereo cylinder through a gear connection and the oscillations are damped by means of an additional friction drive, provided by the ink-rubbing roller.
The ink- and moisture-applying rollers and the stereo cylinder are driven by shape-locking means toothed wheels) or are connected to one another.

Claims (6)

Claims
1. An inking and moistening mechanism for a small rotary offset printing press incorporating an inking mechanism which acts on a stereo cylinder and which includes an ink-duct roller, an ink lifting roller, an intermediate roller and a rubber roller operating on an ink-applying roller for the stereo cylinder, an ink-profile smoothing system having at least one pair of rider rollers which system is arranged dowstream of the rubbing roller in the direction of rotation of the inkapplying roller and operates on the ink-applying roller, and a moistening mechanism which acts on the stereo cylinder and comprises a moisture duct roller, a metering roller rolling thereon, a moisture-applying roller and a moistening-means rubbing roller acting on the moisture-applying roller, said moisture-applying roller being arranged between and in rolling contact with, a moisture-duct roller and the rubbing roller of the moistening-means, and this latter roller being arranged adjacent said one pair of rider rollers or as the case may be the most downstream pair of the rider rollers in the direction of rotation of the ink-applying roller.
2. An inking and moistening mechanism according to Claim 1, wherein a plurality of polishing rollers roll on the moisture-applying roller at its side remote from the stereo cylinder.
3. An inking and moistening mechanism according to Claim 1 or Claim 2, wherein, for the purposes of cleaning and inking-up, the outer roller of the pair of rider rollers, or as the case may be the outer roller of the most downstream pair of rider rollers in the direction of rotation of the inkapplying roller, can be swung about the shaft of the associated inner rider roller rolling on the inkapplying roller into abutment with the rubbing roller of the moistening means.
4. An inking and moistening mechanism according to any one of the preceding claims, wherein the ink-applying roller and the moistureapplying roller are of identical construction in respect of their dimensions and are accommodated in bearings of the same size and properties.
5. An inking and moistening mechanism according to any one of the preceding claims, wherein the ink-rubbing roller and the rubbing roller of the moistening means have identical dimensions, drives and bearings.
6..An inking and moistening mechanism substantially as hereinbefore described with reference to and as illustrated in Figure 1 or Figure 2 of the accompanying drawings.
6. An inking and moistening mechanism as claimed in any one of Claims 1 to 5, wherein a plurality of polishing rollers are in engagement with the ink-applying roller at positions upstream of the rider roller or rollers with respect to the direction of rotation of the ink-appiying roller.
7. An inking and moistening mechanism according to Claim 6 wherein the pair or pairs of rider rollers, and optionally the polishing rollers, are mounted in bearings of similar construction in a common rider roller saddle, which is adapted to execute a rubbing movement in phase with the rubbing roller of the moistening means, and in the opposite phase to the rubbing movement of the ink-rubbing roller.
GB7937093A 1978-10-26 1979-10-25 Inking and moistening mechanism for a rotary offset printing press Expired GB2034250B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19782846701 DE2846701A1 (en) 1978-10-26 1978-10-26 INK AND DAMPING UNIT FOR A SMALL ROTATIONAL OFFSET PRINTING MACHINE

Publications (2)

Publication Number Publication Date
GB2034250A true GB2034250A (en) 1980-06-04
GB2034250B GB2034250B (en) 1982-09-08

Family

ID=6053223

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7937093A Expired GB2034250B (en) 1978-10-26 1979-10-25 Inking and moistening mechanism for a rotary offset printing press

Country Status (4)

Country Link
JP (2) JPS5557469A (en)
DE (1) DE2846701A1 (en)
GB (1) GB2034250B (en)
IT (1) IT1125545B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0282754A3 (en) * 1987-03-14 1990-01-31 Heidelberger Druckmaschinen Aktiengesellschaft Inking and damping device for offset-printing presses
EP0387497A3 (en) * 1989-03-13 1991-04-10 M.A.N.-ROLAND Druckmaschinen Aktiengesellschaft Device for delivering fluids to the plate cylinder of an offset press

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3030076C1 (en) * 1980-08-08 1982-06-16 Rotaprint Gmbh, 1000 Berlin Offset printing machine with an inking and dampening unit

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2689522A (en) * 1949-10-11 1954-09-21 Addressograph Multigraph Inking and moistening means for rotary planographic printing machines
FR1037278A (en) * 1950-05-22 1953-09-15 Rotaprint Ag Printing machine with dampening system
DE1194873B (en) * 1962-06-22 1965-06-16 Agfa Ag Inking unit for rotary printing machines
ZA727427B (en) * 1971-11-17 1973-07-25 Addressograph Multigraph Ink delivery system with continuously rotating ink fountain roll
DE2222581B1 (en) * 1972-05-09 1973-11-15 Heidelberger Druckmasch Ag INKING UNIT FOR OFFSET ROTARY MACHINES
DE2438169C3 (en) * 1974-08-08 1978-04-20 Maschinenfabrik Augsburg-Nuernberg Ag, 8900 Augsburg Rotary offset printing unit in which a transfer roller of the inking unit is provided with a profiled outer surface
GB1585510A (en) * 1976-05-03 1981-03-04 Am Int Lithographic moisture system and method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0282754A3 (en) * 1987-03-14 1990-01-31 Heidelberger Druckmaschinen Aktiengesellschaft Inking and damping device for offset-printing presses
EP0387497A3 (en) * 1989-03-13 1991-04-10 M.A.N.-ROLAND Druckmaschinen Aktiengesellschaft Device for delivering fluids to the plate cylinder of an offset press

Also Published As

Publication number Publication date
JPS5557469A (en) 1980-04-28
JPH01280559A (en) 1989-11-10
IT7926687A0 (en) 1979-10-22
DE2846701C2 (en) 1987-07-02
DE2846701A1 (en) 1980-04-30
JPH0217356B2 (en) 1990-04-20
IT1125545B (en) 1986-05-14
GB2034250B (en) 1982-09-08

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Legal Events

Date Code Title Description
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee