GB2077660A - Lithographic printing presses - Google Patents
Lithographic printing presses Download PDFInfo
- Publication number
- GB2077660A GB2077660A GB8019377A GB8019377A GB2077660A GB 2077660 A GB2077660 A GB 2077660A GB 8019377 A GB8019377 A GB 8019377A GB 8019377 A GB8019377 A GB 8019377A GB 2077660 A GB2077660 A GB 2077660A
- Authority
- GB
- United Kingdom
- Prior art keywords
- roller
- plate
- damping
- printing
- contacts
- 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- Withdrawn
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41F—PRINTING MACHINES OR PRESSES
- B41F35/00—Cleaning arrangements or devices
- B41F35/04—Cleaning arrangements or devices for inking rollers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41F—PRINTING MACHINES OR PRESSES
- B41F35/00—Cleaning arrangements or devices
- B41F35/002—Cleaning arrangements or devices for dampening rollers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41F—PRINTING MACHINES OR PRESSES
- B41F7/00—Rotary lithographic machines
- B41F7/20—Details
- B41F7/24—Damping devices
- B41F7/26—Damping devices using transfer rollers
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Rotary Presses (AREA)
- Inking, Control Or Cleaning Of Printing Machines (AREA)
Abstract
A lithographic printing press which permits the damper roller 3 to be cleaned via the inking system rollers includes (i) a train of inking rollers terminating in a plate inker roller 8 for a plate cylinder 1, (ii) a source of damping solution 2, (iii) a train of damping rollers including a plate damper roller 3 for the plate cylinder 1, a distributor roller 6 and a metering roller 5 and (iv) an additional roller 9. The press is capable of adopting each of the following: (a) a printing configuration wherein both rollers 8 and 3 are in contact with cylinder 1, roller 5 contacts roller 6 and roller 6 contacts roller 3, and roller 9 contacts neither roller 3 nor roller 8; (b) a tripped configuration wherein both rollers 8 and 3 are spaced from cylinder 1, roller 5 contacts roller 6 and roller 6 contacts roller 3, and roller 9 contacts neither roller 3 nor roller 8; and (c) a wash-up configuration as shown wherein both rollers 8 and 3 are spaced from the plate, roller 6 is spaced from roller 3 and roller 5 is spaced from roller 6, and roller 9 contacts both roller 8 and roller 3. Roller 9 may, in normal running, also be allowed to contact either roller 8 or roller 3 to enhance inking or damping. <IMAGE>
Description
SPECIFICATION
Improvements in or relating to lithographic printing presses
This invention relates to a lithographic printing press.
Lithographic printing makes use of a lithographic printing plate which includes image areas which are water-repellent and ink-receptive and non-image areas which are waterreceptive and ink-repellent. In use, an aqueous damping solution is first applied to the lithographic printing plate so as to wet the non-image areas. Greasy ink is then applied.
This is repelled by the wet non-image areas and is retained only in the image areas from whence it is transferred by means of an offset blanket onto the paper or the like to be printed. Ordinarily, the damping solution is applied to the printing plate from a suitable source by means of a damping system comprising a train of damping rollers terminating in a plate damper roller in contact with the printing plate during printing. Similarly, the ink is applied to the printing plate by means of an inking system comprising a train of inking rollers terminating in a plate inker roller in contact with the printing plate during printing.
A built-in roller cleaning device is usually incorporated in the inking system of lithographic printing presses and the incorporation of a built-in roller cleaner for the damping system can show a beneficial reduction in the time taken to clean up the press and thus increase the amount of time available for productive work.
It is one object of the present invention to provide a lithographic printing press with a means whereby damping system rollers can be cleaned via inking system rollers.
The uniformity of ink coverage on the image of a lithographic printing plate in certain difficult circumstances can be improved by including an additional inking roller, preferably arranged to be reciprocable axially over a short stroke. In other circumstances, however, this additional roller may not be needed.
It is another object of the present invention to provide a lithographic printing press with an additional roller which can be used as an inking roller when desired.
In certain circumstances, it is of advantage to include in a lithographic printing press an additional damping roller preferably provided with a means whereby it may be reciprocated axially. However, such an additional damping roller is not always required.
It is a further object of the present invention to provide a lithographic printing press with an additional roller which can be used as an auxiliary damping roller when desired.
According to the present invention, there is provided a lithographic printing press including:
(1) an inking system comprising a train of inking rollers terminating in a plate inker roller for applying ink to the printing plate of the printing press,
(2) a source of damping solution,
(3) a damping system for transferring damping solution from the source to the printing plate and comprising a train of damping rollers terminating in a plate damper roller for applying damping solution to the printing plate, said train of rollers including a distributor roller to apply damping solution to the damper roller and a metering roller to receive damping solution from the source and apply it to the distributor roller, and
(4) an additional roller, the arrangement being such that the rollers can adopt each of the following configurations::
(a) a normal printing configuration wherein (i) both the plate inker roller and the plate damper roller are in contact with the printing plate, (ii) the metering roller contacts the distributor roller and the distributer roller contacts the damper roller, and (iii) the additional roller contacts neither the plate damper roller nor the plate inker roller,
(b) a tripped configuration wherein (i) both the plate inker roller and the plate damper roller are spaced from the printing plate, (ii) the metering roller contacts the distributor roller and the distributor roller contacts the damping roller, and (iii) the additional roller contacts neither the plate damper roller nor the plate inker roller, and
(c) a wash-up configuration wherein (i) both the plate inker roller and the plate damper roller are spaced from the printing plate, (ii) the distributor roller is spaced from the damper roller and the metering roller is spaced from the distributor roller, and (iii) the additional roller contacts both the plate inker roller and the plate damper roller.
When it is desired to wash-up the printing press at the end of a printing run or at the end of a working day, the rollers are placed into the wash-up configuration and washing fluid is applied to the inking rollers. This washing fluid is carried over to damping rollers via the additional roller and these are then cleaned at the same time as are the inking rollers. The dirty fluid is collected by the washing equipment fitted to the inking system from whence it may be removed by, for example, a squeegee blade and be deposited in a trough for removal. There is a substantial advantage in washing up in this way rather than applying washing fluid to the damping system via the printing plate with the inking and damping rollers in their printing position as has been done hitherto.This is particularly so in the case where the ink used is of the type which is curable by polymerisation on exposure to ultra violet radiation. in this case, it is necessary to use specially formulated
cleaning fluids to clean up the rollers and these can attack the image of the printing
plate and cause extensive damage necessitat
ing the making of new plates with consequent
delay and expense. The use of an additional
roller in accordance with the present invention
enables the damping rollers to be cleaned
readily without exposing the plate to attack from the cleaning fluid. In addition, it has
been found that the use of an additional roller
in accordance with the present invention results in more efficient washing.
The press of the present invention will be
placed into the aforementioned tripped confi
guration during short term stoppages during a
printing run when washing up is not required.
In a preferred embodiment, the press may be caused to adopt another configuration, an auxiliary inking configuration, wherein during
printing the additional roller contacts the plate
inker roller only to assist the distribution of the ink. In this configuration, the additional roller remains in contact with the plate inker roller when the latter is tripped away from the printing plate. Similarly, it is advantageous for the press to be able to adopt yet another configuration, an auxiliary damping configuration, wherein during printing the additional roller contacts the plate damper roller only in order to assist in the distribution of the damping liquid and also to scavenge ink from the surface of the plate damper roller and hold it so as to improve the efficiency of the plate damper roller in carrying a film of damping solution.In this configuration the additional roller remains in contact with the damper roller when the latter is tripped from its printing position away from the printing plate.
It is particularly preferred for the additional roller to be provided with a means whereby it may be reciprocated axially. This is particularly useful in the case where severe local build up of ink has occurred on the damping rollers since the resultant local change in the water carrying properties of the surface of the damping rollers can cause tracks to appear in the printed work. The reciprocation of the additional roller whilst the press is in the auxiliary damping configuration minimises this effect and renders any residual track less obvious by smoothing over the feed of water at the edges of the contaminated section of the damping system. In the case where the additional roller is axially reciprocated, it is preferred that a positive geared drive be provided to rotate the additional roller.Otherwise, this additional roller may be friction driven by the rollers with which it is in contact.
The surface of the additional roller is preferably made of an oleophilic material such as copper,. linear polyamide (nylon) or a rubber compound. When functioning in the auxiliary inking configuration, in contact with the plate inker roller, it then carries ink in the presence of water from the damping system some of which is carried into the inking system. When working in the auxiliary damping configuration, the additional roller attracts ink which might otherwise build up on the samper roller surface to the detriment of its water carrying properties and thus minimise ink contamination in the damping system.
In an alternative embodiment, the surface of the additional roller may be made from alternating oleophilic and hydrophilic materials preferably forming a helical pattern. When used in the auxiliary inking configuration, any excessive moisture tends to gather on the hydrophilic areas of the additional roller which constitutes an additional surface area from which this moisture can evaporate and thereby reduce its deleterious effect on the inking. When used in the auxiliary damping configuration, the hydrophilic surface of the additional roller serves to assist the uniform distribution of damping solution across and around the printing plate.
For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which,
Figure 1 is a diagrammatic side view of a lithographic printing press of the present invention in its wash-up configuration,
Figure 2 is a view similar to that of Fig. 1 but with the press in its normal printing configuration,
Figure 3 is a view similar to that of Fig. 1 but with the press in its normal trip position,
Figure 4 is a view similar to that of Fig. 1 but with the press in its auxiliary inking configuration, and
Figure 5 is a view similar to that of Fig. 1 with the press in its auxiliary damper configuration.
Referring to the drawings, the printing press includes a plate cylinder 1 carrying a lithographic printing plate. The press includes a damping system for transferring aqueous damping solution from a reservoir 2 to the printing plate on the plate cylinder 1. This damping system is in the form of a train of damping rollers terminating in a plate damper roller 3 capable of being moved between a position in which it contacts the printing plate during normal printing and a retracted posi- - tion in which it is spaced from the printing plate. The train of damping rollers includes a fountain roller 4 partially immersed in damp ing solution in the reservoir 2, a metering roller 5 arranged to run in contact with the fountain roller 4, and a distributor roller 6 arranged to run in contact with metering roller 5 and the plate damper roller 3 during normal printing (see Fig. 2). The surface of the distributor roller 6 is driven at the same speed as the plate cylinder surface by gears from the plate cylinder 1. The plate damper roller 3 can be tripped further to a position in which it is spaced from the distributor roller 6 as well as being spaced from the printing plate.
Futher, the metering roller 5 can be tripped around fountain roller 4 to a position in which it is spaced from the distributor roller 6. The rollers 4 and 5 are -geared together and driven by means of a variable speed motor (not shown) so that by varying the speed of rotation of these rollers the amount of damp transferred from the reservoir 2 to the plate damper roller 3 can be regulated.
Ink is applied to the printing plate on the plate cylinder 1 by means of an- inking system comprising a train of inking rollers terminating in plate inker rollers (the first of which is denoted by reference numeral 8) moveable between a position in which they are in contact with the printing plate and a position in which they are spaced from the printing plate.
An additional roller 9 is provided and this is arranged to be moveable between a retracted position and a position in which it can contact both the plate inker roller 8 and the plate damper roller 3 when the latter are in their tripped positions spaced from the printing plate and when the plate damper roller 3 is tripped away from the distributor roller 6 and the metering roller 5 is tripped away from the distributor roller 6. The additional roller 9 is positively driven by gears and is axially reciprocable. Also, it can be moved to other positions depending upon its desired use as will be described hereinafter.
During printing, the press is placed into the configuration shown in Fig. 2 so that aqueous damping solution is transferred from the reservoir 2 to the printing plate 1 to wet the nonimage areas thereof and ink is applied to the image areas via the inker roller 8. Ink is then transferred from the image onto the material to be printed by means of an offset blanket on a blanket cylinder (not shown) using an impression cylinder (not shown) in conventional manner.
When it is desired to have a short break during printing, all of the plate inker rollers are tipped away from the plate and the plate damper roller 3 is tripped away from the plate as shown in Fig. 3. In this configuration, the additional roller 9 is still clear of the inking and damping systems.
When it is desired to wash up the press after a printing run, the plate inker and damper rollers are tripped away from the plate as shown in Fig. 3 and additionally the plate damper roller 3 is tripped away from the distributor roller 6 and the metering roller 5 is tripped away from the distributor roller 6.
Also, the additional roller 9 is moved into a position where it contacts the tripped plate inker roller 8 and the tripped plate damper roller 3 as shown in Fig. 1. Roller cleaning fluid is applied to the inking system and is carried over onto the plate damper roller 3 by
means of the additional roller 9 and thus plate
damper roller 3 is also cleaned up at the same
time.
When, during printing, it is desired to rein
force the inking, the additional roller 9 is
tripped from the position shown in Fig. 2 to
another position in which it is in contact with
the plate inker roller 8 (Fig. 4). When it is
desired to reinforce the damping, the addi
tional roller 9 is tripped from the position
shown in Fig. 2 to yet another position in
which it contacts the plate damper roller 3 as
shown in Fig. 5.
Claims (11)
1. A lithographic printing press including
an arrangement comprising:
(1) an inking system comprising a source
of ink and a train of inking rollers terminating
in a plate inker roller for applying ink to the
printing plate of the printing press,
(2) a source of damping solution,
(3) a damping system for transferring
damping solution from the source to the print ing plate and comprising a train of damping
rollers terminating in a plate damper roller for
applying damping solution to the printing
plate, said train of damping roller including a
distributor roller to apply damping solution to
the plate damper roller and a metering roller
to receive damping solution from the source
and apply it to the distributor roller, and
(4) an additional roller, the arrangement
being such that the rollers can adopt each of
the following configuration::
(a) a normal printing configuration wherein
(i) both the plate inker roller and the plate
damper roller are in contact with the printing
plate, (ii) the metering roller contacts the
distributor roller and the distributor roller con
tacts the plate damper roller, and (iii) the
additional roller contacts neither the plate
damper roller nor the plate inker roller;
(b) a tripped configuration wherein (i) both
the plate inker roller and the plate damper
roller are spaced from the printing plate, (ii)
the metering roller contacts the distributor
roller and the distributor roller contacts the
plate damper roller, and (iii) the additional
roller contacts neither the plate damper roller
nor the plate inker roller; and
(c) a wash-up configuration wherein (i)
both the plate inker roller and the plate dam
per roller are spaced from the printing plate,
(ii) the distributor roller is spaced from the
plate damper roller and the metering roller is
spaced from the distributor roller, and (iii) the
additional roller contacts both the plate inker
roller and the plate damper roller.
2. A press according to claim 1 which is
capable of adopting an auxiliary inking confi
guration (d) wherein during printing the addi
tional roller contacts the plate inker roller
only, so as to assist the distribution of the ink,
said contact being maintained when the plate inker roller is tripped away from the printing plate.
3. A press according to claim 1 or 2 which is capable of adopting an auxiliary damping configuration (e) wherein during printing the additional roller contacts the plate damper roller only, so as to assist the distribution of the damping fluid, said contact being maintained when the plate damper roller is tripped away from the printing plate.
4. A press according to claim 1, 2 or 3 wherein the additional roller is provided with means whereby it may be axially reciprocated.
5. A press according to claim 4 wherein the additional roller is provided with means whereby it may be positively driven.
6. A press according to any one of the preceding claims wherein the additional roller has a surface comprising an oleophilic material.
7. A press according to claim 6 wherein the oleophilic material is copper, a linear polyamide or a rubber compound.
8. A press according to any one of claims 1 to 5 wherein the additional roller has a surface comprising a hydrophilic material.
9. A press according to any one of claims 1 to 5 wherein the additional roller has a surface comprising alternating oleophilic and hydrophilic materials forming a helical pattern.
10. A press according to claim 1 substantially as described with reference to any figure of the accompanying drawings.
11. A press according to claim 1 substantially as hereindescribed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8019377A GB2077660A (en) | 1980-06-13 | 1980-06-13 | Lithographic printing presses |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8019377A GB2077660A (en) | 1980-06-13 | 1980-06-13 | Lithographic printing presses |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2077660A true GB2077660A (en) | 1981-12-23 |
Family
ID=10514032
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8019377A Withdrawn GB2077660A (en) | 1980-06-13 | 1980-06-13 | Lithographic printing presses |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2077660A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2212106A (en) * | 1987-12-22 | 1989-07-19 | Heidelberger Druckmasch Ag | Offset printing machine dampening/inking unit |
| EP0450155A1 (en) * | 1990-04-05 | 1991-10-09 | MAN Roland Druckmaschinen AG | Humidification and inking method for a printing plate positioned on a plate cylinder |
| US5060568A (en) * | 1981-02-26 | 1991-10-29 | Veb Kombinat Polygraph "Werner Lamberz" Leipzig | Distributing roller unit and printing mechanism provided therewith |
| EP0455008A2 (en) * | 1990-04-28 | 1991-11-06 | Heidelberger Druckmaschinen Aktiengesellschaft | Offset printing machine with an intermediate roller connecting the inking and the dampening unit |
| EP0478493A1 (en) * | 1990-09-11 | 1992-04-01 | Sun Graphic Technologies, Inc. | Press dampening system |
| FR2680479A1 (en) * | 1991-08-22 | 1993-02-26 | Heidelberger Druckmasch Ag | WETTING MECHANISM FOR OFFSET PRINTING MACHINES. |
| US5447102A (en) * | 1993-04-14 | 1995-09-05 | Heidelberger Druckmaschinen Aktiengesellschaft | Process for operating a printing press |
| EP0774353A1 (en) * | 1995-11-07 | 1997-05-21 | Heidelberger Druckmaschinen Aktiengesellschaft | Offset printing machine |
-
1980
- 1980-06-13 GB GB8019377A patent/GB2077660A/en not_active Withdrawn
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5060568A (en) * | 1981-02-26 | 1991-10-29 | Veb Kombinat Polygraph "Werner Lamberz" Leipzig | Distributing roller unit and printing mechanism provided therewith |
| GB2212106A (en) * | 1987-12-22 | 1989-07-19 | Heidelberger Druckmasch Ag | Offset printing machine dampening/inking unit |
| GB2212106B (en) * | 1987-12-22 | 1992-02-26 | Heidelberger Druckmasch Ag | Offset printing machine dampening/inking unit |
| EP0450155A1 (en) * | 1990-04-05 | 1991-10-09 | MAN Roland Druckmaschinen AG | Humidification and inking method for a printing plate positioned on a plate cylinder |
| EP0455008A2 (en) * | 1990-04-28 | 1991-11-06 | Heidelberger Druckmaschinen Aktiengesellschaft | Offset printing machine with an intermediate roller connecting the inking and the dampening unit |
| EP0455008A3 (en) * | 1990-04-28 | 1992-02-12 | Heidelberger Druckmaschinen Aktiengesellschaft | Offset printing machine with an intermediate roller connecting the inking and the dampening unit |
| EP0478493A1 (en) * | 1990-09-11 | 1992-04-01 | Sun Graphic Technologies, Inc. | Press dampening system |
| FR2680479A1 (en) * | 1991-08-22 | 1993-02-26 | Heidelberger Druckmasch Ag | WETTING MECHANISM FOR OFFSET PRINTING MACHINES. |
| GB2259056A (en) * | 1991-08-22 | 1993-03-03 | Heidelberger Druckmasch Ag | Dampening unit for an offset printing machine |
| GB2259056B (en) * | 1991-08-22 | 1994-12-07 | Heidelberger Druckmasch Ag | Dampening unit for an offset printing machine |
| US5375522A (en) * | 1991-08-22 | 1994-12-27 | Heidelberger Druckmaschinen Ag | Method and apparatus for washing a printing press in conjunction with a damping unit |
| US5447102A (en) * | 1993-04-14 | 1995-09-05 | Heidelberger Druckmaschinen Aktiengesellschaft | Process for operating a printing press |
| EP0774353A1 (en) * | 1995-11-07 | 1997-05-21 | Heidelberger Druckmaschinen Aktiengesellschaft | Offset printing machine |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |