JP2519002B2 - Rotary printing machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention comprises a plate cylinder for different printing widths and an impression cylinder cooperating with the plate cylinder for printing different widths of the printing web. The invention relates to a rotary printing press adapted to exert individually adjustable pressing forces on different width printing webs.

[0002]

2. Description of the Related Art A rotary printing press of this kind is known from EP-A-4.
No. 39 822, the rotary printing press also allows printing webs of different widths to be printed qualitatively reliably by means of its own impression cylinder. For this purpose, the impression cylinder has a large number of at least partially individually adjustable support elements arranged axially side by side, which support elements are arranged on the impression cylinder upholstery. In addition, different pressing forces can be applied according to the print width. In the end region of the impression cylinder, a support element is additionally provided which acts in the opposite direction to the pressing direction in order to pull the impression cylinder away from the plate cylinder.

In a so-called proofing machine, in which a new plate is inspected and a proof is taken out, the same proofing machine is used.
One after another, it is required to be able to mount various plates having different printing widths. For this reason, it is common to proof print plate cylinders for continuous printing machines having different working widths on the same proofing machine.
In addition to the variable plate cylinder bearing, a printing ink pan with adjustable width is provided.

Similarly, in impression cylinder systems, corresponding measures must be taken to switch to other working widths. If, within the cylinder body, a wider, more modest impression cylinder is used than the plate cylinder, essentially two problems arise. -The doctor system does not clean the plate cylinder cleanly in the edge region; this results in the transfer of printing ink to the impression cylinder: -the edges of the plate cylinder are Tendency to local overload on the tension; this results in contact scars in the torso: and so on.

Therefore, as is usual, in a certain way, a large number of impression cylinders with correspondingly tuned working widths are loaded into the swivel system. The associated impression cylinder, which has a corresponding pressing width, is then swiveled into the working position by the swivel system for proofing a plate with a defined working width. However, this requires a relatively complex construction and, according to the working width to be expected, requires the storage of a large number of impression cylinders. Moreover, the conversion to other working widths is very time consuming.

The rotary printing press known from EP-A-439 822 also uses plate cylinders of different working widths without problems, despite the individually adjustable pressing force over the width. Used for proofs. In the impression cylinder, in order to avoid the formation of printing ink at the edges of the plate, the upholstery is separated from the plate cylinder in this region by the counteracting support elements, which results in the printing of the plate cylinder. A small gap must be created between the area contaminated with ink and the impression cylinder tension. It is therefore possible to separate the ends of the cylinder upholstery, but over time, via the contact point of the printing ink, on the impression cylinder, an area of the printing ink forms
Finally, until the gap between the impression cylinder and the plate cylinder is filled,
Can be formed. The transfer of the printing ink is not a direct impediment in itself, however, over time, it swells in the edge region of the upholstery of the impression cylinder, causing a local increase in diameter, which Sufficient to negatively affect edge / center color fusion. Moreover, the upholstery of the impression cylinder is impaired and damaged by the printing ink-melting material.

To a certain extent, an increase in the retraction pressure of the impression cylinder tension improves the separation from the plate cylinder, however,
Then, in the edge region, the pressing force is reduced so that the proof in this region is inadequate.
On the other hand, if the receding pressure is reduced to the extent that the proof is sufficient, then again printing ink can be transferred.

Similar problems generally occur in decorative printing where the proof is printed with the maximum plate cylinder width. In that case, the plate cylinder is engraved over the entire width, but then usually only a partial upholstery is effected by the material to be printed. The change of the width of the material can then be carried out in steps of a few mm, which means that the proofing system has a very delicate staging and usually a correspondingly large number of different impression cylinders. I need. Here too, without staging of the impression cylinder, the contents of the printing ink in the small depressions lying on the outside of the web material are transferred onto the impression cylinder. In this case, too, a simple bending of the impression cylinder in the region outside the web material only results in an improvement for a short time at most.

[0009] Research has already been carried out on the use of adhesive bands to cover areas of the impression cylinder at risk of contamination. However, the production of adhesive bands is relatively complicated and is far from suitable for continuous operation. The removal and replacement of the adhesive band is, in addition, cumbersome and, in fact, can only be achieved with difficulty.

[0010]

SUMMARY OF THE INVENTION The present invention eliminates the above-mentioned disadvantages of the prior art, in particular a rotary printing press of the type mentioned at the beginning with different plate widths by the same impression cylinder. It is intended to be formed so that it can be used on a plate cylinder without impairing print quality.

[0011]

According to the present invention, in order to solve this problem, the pressing force on the impression cylinder is set above the width of the impression cylinder.
It is controlled so that a reduction of the pressing force between the impression cylinder and the plate cylinder takes place as follows, i.e. on both sides of the outside of the printing web, and the reduced pressing force between the impression cylinder and the plate cylinder is Rotary printing presses, each provided with one axially guided, ring-shaped protective sleeve loosely rotating with the impression cylinder, which encloses the impression cylinder in a small space in the region of pressure It is characterized by.

The reduction in force prevents the formation of an incoming corner of the printing ink in the area of the end of the ring-shaped protective sleeve.

[0013] The ring-shaped protective sleeve, thinner, is formed as a highly deflectable metal ring, one edge of the metal ring is sandwiched between the impression cylinder and the plate cylinder, and the other edge Is connected to the guide bearing, which
It is advantageous for the surface of the impression cylinder to be protected and coated against jets of printing ink. Installation of the guide bearings can be done by the device manually or automatically,
It is formed at each charging location so that it can be pushed forward.

In addition, it is advantageous to provide a device, for example a doctor knife, for removing the residue of the applied printing ink from the link-shaped protective sleeve in the direction of rotation of the ring-shaped protective sleeve. . This is because otherwise undesired continuous formation of dried printing ink can occur.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings showing the embodiments thereof. In the proof machine shown in FIG. 1, a plate cylinder 1 having a plate on its upper surface is replaced by an impression cylinder 2
Together with act on the print web 3 to be printed. The plate cylinder 1 fits another plate cylinder 1'having another printing width with the bearings 4 or 4'of the plate cylinder 1 or 1 ',
It can be selectively replaced.

On the other hand, in the calibrator shown in the drawings, in the case of various different working widths and plate cylinder widths, unlike the known calibrators having exchangeable impression cylinders, there is always a constant value. It is operated by the impression cylinder 2 having the same width. In order to adapt to different working widths, the impression cylinder 2 is formed as follows, that is to say that this impression cylinder 2 can exert an individually adjustable pressing force on its width. Has been done. In particular, in the region of the working width of the printing web 3 or of the plate cylinder 1, a pressing force P in the printing direction acts on the plate cylinder 1, while at the free end 2 ′ of the impression cylinder 2 it recedes. The force R acts against the printing direction, but this receding force R pulls the end 2 ′ of the impression cylinder 2 from the printing surface and the plate cylinder 1.

In addition, the impression cylinder 2 is, for example, as described in EP-A 139 822, in order to achieve the possibility of individual adaptation of the pressing force over the width and the generation of a receding force at the ends. A non-rotatable carrier 5 and a body covering 6 rotatable around it can be formed on this.
Are supported against the carrier 5 by a pressing force that can be adjusted individually or in groups by means of a series of supporting elements 7 arranged side by side in the axial direction. In that case, in the end region, in order to apply the backward force R, additionally,
Supporting elements are provided on the opposite side of the upholstery 6.

The support elements 7 are formed as hydrostatically following elements, which support elements 7 advantageously enable a wide range of friction-free bearings of the upholstery 6 independent of the pressing force. is there. However, instead of a series of support elements 7, the impression cylinder 2 is also conventionally formed, for example, as a so-called bending impression cylinder, in which case a pressing force can be generated in the operating position. However, in the edge region it can also be formed in such a way that oppositely directed retracting forces can be generated.

As can be seen from FIG. 2, the plate cylinder 1
On its outer edge, a small chamfered, or have a chamfered 8. In each case, the impression cylinder 2 is lightly retracted in a region 2 ′ outside the working width of the printing web 3 or the plate cylinder 1, whereby the linear force in this region is significantly reduced. To do so. Edge 8 of plate cylinder 1
A small wedge-shaped clearance K is formed between the plate cylinder 1 and the cylinder tensioner 6 of the impression cylinder 2, and the plate cylinder 1 and the impression cylinder 2 are mutually connected in the end region through the clearance K. It is advantageous to be separated.

The upholstery 6 of the impression cylinder 2 is usually made of a highly elastic material having sufficient flexibility in order to achieve good print quality, in which case in addition other requirements As long as it has to be processed, for example by electrostatic pressing means, the requirements regarding the electrical resistance value should be fulfilled. However, commonly used materials are sensitive to printing ink traces that may reach from the plate cylinder 1 onto the edges of the cylinder tensioning 6. The printing ink or the solvent contained therein, such as toluol, attack and partially swell conventional impression cylinder materials, which can be a problem in fast depletion and in the supply of printing webs. is there.

The impression cylinders 2 do not have to be replaced and adapted together either when changing the plate or when changing its width, and work further with the same impression cylinder. In the end region of the plate cylinder 1, one ring-shaped protective sleeve 9 is provided on each side so that the ring-shaped protective sleeve 9 can be attached to the cover 6 of the impression cylinder 2. The surface is coated in the edge areas to protect the transfer of printing ink. This ring-shaped protective sleeve 9 is, for example, an endless ring-shaped protective sleeve 9 having a wall thickness of about 0.1 mm and a number c.
It consists of a spring steel band having a width of m.
In particular, spring steel bands must be used without abutting points. For example, a thin-walled nickel ring produced by "electroforming" must be used. Templated synthetic resin rings are also contemplated. The diameter of the ring-shaped protection sleeve 9 is larger than the outer diameter of the impression cylinder 2.
Slightly larger. The diameter difference is ring-shaped protective sleeve 9
Is advantageously selected such that it can loosely rotate with the impression cylinder 2. Normally, in the case of an ordinary impression cylinder diameter in the range of 25 cm, the maximum outside diameter of the cylinder is 0.
The inner diameter of the ring-shaped protective sleeve 9 is larger than 5-5 cm, preferably 3-4 cm.

The ring-shaped protective sleeve 9, between the outer edge of the trunk tension 6 and the plate cylinder 1 of the impression cylinder 2, it <br/> outside edge of the printing web 3, for example, from the edge of the paper, Placed to have a distance of about 5 mm or slightly less. For positioning of the ring-shaped protective sleeve 9, the outer edge is secured on the guide ring 10 is rotatable by a bearing 11 around the non-rotatable outer ring 12. Therefore, during operation of the calibrator, the ring-shaped protective sleeve 9 is carried along with the guide ring 10 on the impression cylinder 2 and rotates with it, however, it corresponds to different diameters. And rotate at a slightly different speed. The bearing 11 is
An inner flange 10 ′ provided on the protective ring 10 protects against jetting of printing ink.

The non-rotatable ring 12 is fixed to the frame 13 of the calibrator so as to be adjustable in the axial direction and movable in the radial direction. This anchorage is preferably formed vertically movable by a kind of spring member, so that the outer ring 12 can follow the stroke movement of the impression cylinder 2 and the spring always points towards the impression cylinder. To be pulled. It is thus possible in a simple manner to adapt the ring-shaped protective sleeve 9 to a modified working width or a modified plate cylinder diameter. Therefore, the impression cylinder 2 is provided with a simple adaptation of the position of the protective sleeve 9 without any risk of obstruction or damage to the end 2'overlying the impression cylinder 2 and any plate cylinder 1 and working width 3 To be adapted without problems.

In order to remove the rest of the printing ink which reaches on the ring-shaped protective sleeve 9, for example on both sides,
In order to scrape off the printing ink which has reached the one ring-shaped protective sleeve 9 respectively, the doctor knife 1
It is advantageous to provide 4. This doctor knife 14
Can be mounted on the non-rotatable ring 12 behind the print gap in the direction of rotation

In the case of decorative printing, the solution according to the invention is also used to advantage. Figure 3 for decorative printing
As can be seen from the figure, it is operated with a maximum plate cylinder width, in which case the plate cylinder 1 has a decorative pattern over the entire width, for example engraved. However, in most cases, the paper 3 is merely on the partial upholstery on the working width B which is present in each case. Instead of working with an impression cylinder tuned to this working width B, the impression cylinder 2 with the largest width is used. In this case too, the impression cylinder 2 is subjected to a printing pressure P in the working width B, while the end 2 ′ of the impression cylinder is separated from the plate cylinder 1 by a corresponding reaction force R. In this case, too, the edges of the paper web 3 are
In contact with each other, one ring-shaped protective sleeve 9 is provided, the diameter of which is slightly larger than the outer diameter of the impression cylinder 2, and this ring-shaped protective sleeve 9 together with the impression cylinder 2 is provided. Rotate loosely. The ring-shaped protective sleeve 9 is in this case clamped in its entire width in the gap between the plate cylinder 1 and the impression cylinder 2, so that a guide of another ring-shaped protective sleeve 9 must be selected. Instead, a protective sleeve, for example in the form of a ring, can be guided laterally via the guide element, which is then scraped off in the lower region, which means that the unit is above the body width. To be able to move without problems. The guide member can be made of, for example, a suitable synthetic resin, such as Teflon PA6, or the like, and can at the same time serve as a holder for the doctor knife.

The guide member includes a ring-shaped protective sleeve,
It is also conceivable to provide guidance only partially, for example at three locations. This guide point can also be formed as a roller.

[0027]

Since the present invention has the above-described structure and operation, it eliminates the above-mentioned drawbacks of the prior art, and in particular, a rotary printing machine of the type described at the outset,
It is intended to provide a proofing machine configured so that different plate widths can be used on the plate cylinder by the same impression cylinder without impairing print quality.

[Brief description of drawings]

FIG. 1 is a side view of a calibrator according to the present invention.

FIG. 2 is a detailed cross-sectional view of the calibration machine of FIG.

FIG. 3 is a side view of a decorative printing machine according to the present invention.

[Explanation of symbols]

 1 plate cylinder 2 impression cylinder 3 printing web 4 bearing 5 carrier 6 cylinder tension 7 support element 8 chamfer 9 ring protective sleeve 10 guide ring 11 bearing 12 non-rotatable ring 13 frame

Claims (10)

(57) [Claims] 1. A printing cylinder (1) for different printing widths,
An impression cylinder (2) cooperating with the plate cylinder for printing on printing webs of different widths, the impression cylinder (2) having a pressing force (P).
In a rotary printing press provided with means for individually adjusting , the pressing force (P) on the impression cylinder (2) is
Over the width, as it follows, namely, in the printing both sides of the web (3), between the impression cylinder (2) and the plate cylinder (1)
Of the impression cylinder (2) is controlled so that a decrease in the impression pressure of the impression cylinder occurs, and the impression cylinder (2) is small within the area of reduced depression force between the impression cylinder (2) and the plate cylinder (1). Enclose at intervals and follow the impression cylinder (2).
A rotary printing press, characterized in that each is provided with one ring-shaped protective sleeve (9) which extends axially and rotates loosely together with the impression cylinder (2). 2. The rotary printing press as claimed in claim 1, wherein the ring-shaped protective sleeve (9) which rotates loosely together has a diameter which is slightly larger than the outer diameter of the impression cylinder (2). 3. The inner diameter of the ring-shaped protective sleeve (9) which rotates together loosely is 0.5 than the outer diameter of the impression cylinder (2).
A rotary printing press according to claim 2, wherein the rotary printing press is larger than -5 cm, preferably larger than 3-4 cm. 4. A ring-shaped protective sleeve (9) which rotates loosely together is journaled in a frame (13) of a rotary printing press by guide bearings (10, 11, 12). Or 3 rotary press. 5. The guide bearing (10, 11, 12) of the ring-shaped protective sleeve (9) rotating together is adjustable in the axial direction of the impression cylinder (2).
Rotary printing machine. 6. A guide bearing (10, 10 ) on the frame (13) .
6. The rotary printing press according to claim 5, wherein (11, 12) are preferably arranged by a kind of elastic member so as to be movable in the radial direction in the pressing direction. 7. inner edge of the ring-shaped protective sleeve (9), with the plate cylinder (1) and impression cylinder (2), then the outer edges of the printed web (3), the number at most mm The rotary printing press according to any one of claims 1 to 6, wherein the rotary printing presses are arranged so as to have a small interval of the order of. 8. Carrier (5) in which the impression cylinder (2) is stationary
And a upholstery (6) rotatable around the carrier (5), the upholstery (6) being provided by a set of supporting elements (7) arranged axially side by side. It is supported against a carrier (5), in which case the support element (7) can exert an adjustable pressing force (P) in the printing direction in the area of the printing web (3), while At the end of the printing web (3) there is a retracting element (7 '), which retracting element (7') is capable of exerting a retracting force (R) opposite to the printing direction. The rotary printing press according to any one of claims 1 to 7, wherein: 9. plate cylinder (1) is an end portion of the plate cylinder (1), so that a gap (K) is formed between the impression cylinder (2), inclined or chamfered on its outer edge Claim 1 having (8)
[8] The rotary printing press according to any one of [8] to [8]. 10. The rotary printing press as claimed in claim 1, wherein a doctor knife (14) is provided for scraping off the remainder of the printing ink from the ring-shaped protective sleeve (9).