EP1894723B1 - Arrangement of blankets on printing cylinders of a printing machine. - Google Patents

Abstract

The press has an impression cylinder (1), where printing blankets are arranged axially in parallel to the cylinder. A gap (10a), which runs in a circumferential direction is formed between the blankets. Printing blankets, which are arranged axially in parallel to an impression cylinder (2), roll on the blankets of the cylinder (1). A gap (10b) is formed between the blankets of the cylinder (2). The gaps are displaced axially to each other, in such a manner that the gap (10a) rolls up on the blankets of the cylinder (2) and the gap (10b) rolls up on the blankets of the cylinder (1).

Description

The invention relates to the arrangement of printing blankets on printing cylinders of the rotary printing press in a rotary printing press. The rotary printing machine is preferably a web-fed printing machine. The machine preferably works in offset printing, either in dry offset or advantageously in wet offset. The machine may in particular be a newspaper printing press, preferably for the printing of large newspaper editions.

In printing units in which pressure cylinders occupied by Drucktüchem form a pressure nip for a traversing between the printing cylinders web, in the transition region of axially adjacent blankets in web material waves and wrinkles can result. The wave formation can lead to passer problems, for example to a distorted image or illegible texts. The problems are caused by either too strong or too weakly stretched blankets. Over the circumference of a printing cylinder to excessively tensioned blankets tend to "constrict", so that a gap arises between axially adjacent blankets. One too small. Blanket tension leads to an overlap of the axially adjacent blankets. Both states lead in the nip of two impression cylinders over the web width to locally different effective diameters of the two successive rolling pressure cylinder including their blankets and thus to uncontrolled web transport behavior.

From the DE 10 2004 055 704 A1 Arrangements of printing cylinders on axially juxtaposed Drucktüchem are known in which the course of the adjacent side edges of the blankets deviates from the unwinding direction of the blankets. In other blankets, the side edges are serrated or meandering.

From the WO 2006/133938 A2 For example, a transfer cylinder for printing at least five pages wide is known, having first and second mounting channels for the blankets. The fastening channels are arranged in different axial sections of the cylinder and offset in the circumferential direction of the cylinder by 180 ° to each other. In the mounting channels printing blankets can be arranged side by side, which may have a width of one, two, three or four printing page.

It is an object of the invention to eliminate problems such as may arise from constricting or overlapping printing blankets and thereby improving print quality.

The invention is based on a rotary printing machine which comprises a first printing cylinder and a second printing cylinder, which together form a printing gap for a continuous web, preferably a paper web, and which are each covered with at least two blankets arranged axially next to one another. The blankets serve to transfer color to the web. The printing blankets preferably span the respective associated printing cylinder over its entire circumference, more precisely over almost the entire circumference. In such a blanket, the leading end and the trailing end are secured in the same nip of the associated printing cylinder. In principle, however, it is also possible that a plurality of printing blankets are arranged one behind the other over the circumference of one or both printing cylinders, for example two printing blankets. If a plurality of printing blankets are arranged one behind the other over the circumference of a blanket cylinder, it is further preferred if this applies to all blankets of the respective printing cylinder arranged next to one another axially. Deviating from this, however, it would in principle be possible for a blanket in an axial section of the relevant printing cylinder to encompass its entire circumference, while in another axial section of the same printing cylinder a plurality of blankets are arranged one behind the other in the circumference. The printing blankets, each adjacent to one another axially adjacent to one of the printing cylinders, form a gap between them in an axial transition region. The axially adjacent printing blankets are preferably in abutment with one another, ie they are in contact with one another in the circumferential direction along their two mutually facing side edges, so that the gap is linear.

According to the invention, a circumferentially extending gap between blankets of the first printing cylinder on an axial offset to a gap between two blankets of the second printing cylinder. In this way, it is ensured that the two columns can not roll on each other, but always only on the respective opposite blanket of the respective printing cylinder. In printing operation, when passing through a train to be printed between the two printing cylinders, the gaps roll directly on the web and across the web on the opposite blanket. The invention is thus based on the recognition that mutually rolling blanket gaps are a major cause of the initially described wave and wrinkling of the web and thus of passer problems. An axial offset of, for example, one millimeter or a few millimeters already suffices, so that the axial distance between the set levels of two axially adjacent print sides is completely sufficient to allow the axially offset gaps to roll between the adjacent typesetting mirrors. Since each of the column rolls on an opposite smooth blanket, a wrinkling of the web is no longer to be feared. A further advantage is that the invention also requires none of the unwinding of the blankets deviating course of the side edges of the blankets, although the use of blankets with such side edges should not be excluded. In preferred embodiments, however, the blankets have side edges which are straight over their entire length and preferably extend in the circumferential direction of the respective printing cylinder. In such embodiments, the blankets each have a constant width over their entire length measured in the circumferential direction, which is measured between the parallel side edges in the axial direction of the associated printing cylinder. The leading edge and the trailing edge are preferably straight. In such embodiments, the blankets in the settlement are rectangular.

The blankets consist at least to a greater extent of an elastically yielding material. Preferred examples are the blankets known from offset printing. The compliant material of the blankets may be secured in the clamping channel or channels of the associated printing cylinder. Preferably, however, the compliant material is on one at the periphery of the Pressure cylinder applied to the thin carrier plate applied, for example, on a metal plate, and there are the leading and the trailing end of the plate in the clamping channel or in each fixed in a different of several clamping channels.

The invention is used with advantage in four-page-wide and six-page-wide printing cylinders, but is not limited to these width formats. Four-page-width printing cylinders are preferably covered with two blankets arranged axially next to one another, which, as already mentioned, preferably extend over almost the entire circumference of the printing cylinder. In principle, however, more than two printing blankets can also be arranged axially next to one another on such printing cylinders. Six-page-wide impression cylinder are occupied in preferred embodiments with three axially juxtaposed blankets, which preferably each extend over almost the entire circumference of the respective printing cylinder. In principle, six-page-wide printing cylinders but also more than three blankets can be arranged axially next to each other. Furthermore, alternatively, only two blankets can be arranged axially next to one another on a six-page-wide printing cylinder, wherein the two blankets occupy the entire printing width in the axial direction of the cylinder. If one of the two blankets has, for example, a width of two-thirds of the entire printing width of the printing cylinder and the other of the blankets accordingly a width of one third of the entire printing width of the printing cylinder, it is sufficient for the inventive offset of the blanket column, if on the other printing cylinder, the impression gap co-forming counter-pressure cylinder, axially juxtaposed two just such blankets are arranged, wherein the arrangement is chosen so that the 1/3-wide blanket of a printing cylinder rolls on the 2/3-wide blanket of the other printing cylinder. This means that in a plan view of the two printing cylinders in the one of the printing cylinder, the 1/3-wide blanket is located to the left of the axial center of a printing cylinder and the 1/3 wide blanket of this printing cylinder to the right of its axial center.

The printing cylinders have axially adjacent printing sections for printing at least one printed page, for example a newspaper page. Preferably have the printing sections each the width of two printed pages. On at least one of the impression cylinders, which together form a printing nip, at least two printing blankets arranged axially next to each other, each of which occupy an associated printing section of the plurality of printing sections of the printing cylinder, are arranged axially asymmetrically with respect to the respective associated printing section. The axial centers of the printing blankets are offset axially relative to an axial center of the respective associated printing section. Such an arrangement of the blankets is advantageous, in particular, when the respective blankets, as preferred, each have at least substantially only the width of a single printing section. This means that one or more of the printing blankets have either the exact width of the respectively assigned printing section or a certain oversize or undersize for the respectively assigned printing section. Per printing cylinder all blankets or only a portion of the blankets, possibly even one of the axially juxtaposed blankets, have an excess. Optionally, one or more of the juxtaposed blankets may also have an undersize in comparison to the width of the associated printing section, ie be narrower than the associated printing section, if the undersize is offset by an oversize in at least one other of the juxtaposed blankets. Overall, the axially juxtaposed blankets occupy the entire axial, usable for printing web width of the respective printing cylinder. The respective oversize or possibly undersize and the respective axial offset are in coordination with each other so small that none of the blanket gaps gets into one of the type area to be printed. The oversize or undersize is advantageously at least 1 mm and advantageously at most 20 mm, more preferably at most 15 mm.

In preferred first embodiments, the blankets of at least one of the printing cylinders are all the same width. The blankets of the other printing cylinder can have different widths among each other. In such a constellation, the uniform printing blankets may, for example, have the width of the respectively assigned printing section and the nip or the nip of the printing blankets arranged axially next to one another run exactly along a dividing line at which the respective associated printing sections adjoin one another. Because the blankets or at least one Part of the blankets of the other printing cylinder to the width of the respective associated printing section of the other printing cylinder have an oversize or undersize, results in an inventive axial offset at the same subdivision of the printing cylinder in print sections automatically. In order to reduce the manufacturing costs and to simplify the blanket logistics, the blankets of the other blanket cylinder can each also have the same width each other. More preferably, the blankets of both printing cylinders are the same width. In such a constellation, the blankets are arranged on at least one of the two pressure cylinders together forming pressure cylinder axially asymmetric on the respective printing cylinder by the axial centers of these blankets are axially offset to the axial center of each associated printing section of the respective printing cylinder. If the rotary printing machine as preferred has a plurality of pairs of printing cylinders which form a printing gap in pairs and are each covered with blankets as described above, advantageously the blankets of all printing cylinders or not yet mounted blankets for all printing cylinders have the same width.

In preferred second embodiments, at least one of the printing gap forming printing cylinder is covered with blankets of different widths. Such a blanket coverage is especially for wide printing cylinder in question, for example, six-page wide or eight-page wide or optionally also five- or seven-page wide printing cylinder, but in principle for narrower printing cylinder, for example, four-page wide printing cylinder. The other impression cylinder can be covered with mutually uniform printing blankets, as already explained in the preceding paragraph. Advantageously, however, the other printing cylinder can be covered with blankets of different widths. In the second embodiments, in a further development on at least one of the printing cylinders, which together form a printing nip, printing blankets are arranged in exactly two different widths axially next to one another, preferably in an axially alternating sequence, followed by a narrower of the blankets on a wider of the blankets , For such embodiments, it is further preferred if the other cylinder, ie the impression cylinder, is covered with blankets in two different widths, wherein the blankets of different width in the axial direction are preferably also arranged alternately. Further, it is preferred that in such embodiments for both printing cylinder blankets are used only in two different widths. With regard to the alternating sequence, it is advantageous if a printing blanket with the greater width is opposite a printing blanket with the smaller width, ie if the alternating sequence of blankets on one of the two printing cylinders is accompanied by an inversely alternating sequence on the other of the two printing cylinders. Such an arrangement of the blankets ensures a particularly low-vibration and therefore quiet running of the printing cylinder, while the manufacturing costs and to be operated for the storage and handling of the blankets logistical effort, on the other hand, are still limited. As in the case of the first embodiments, it is also preferred in the case of the second embodiments if all printing cylinders of the printing press, which in each case form a printing gap in pairs with one another, are covered with printing blankets in the same way.

Also, a combination of blankets is described, namely a set of blankets as such, which are intended for mounting on one or more printing cylinders of the same rotary printing press. The blanket set is used to equip a rotary printing machine or, if desired, only a printing cylinder of a rotary printing press according to the preferred second embodiments. The blanket set accordingly comprises a first blanket of a first nominal width and at least one second blanket of a second nominal width which is greater than the first nominal width. The nominal width is the width of the blanket before mounting on the associated impression cylinder. The width is accordingly measured in the unloaded state between the side edges of the resilient material of the blanket in question, as in the case of the claimed assemblies of blankets. The side edges extend over the entire, measured between the leading end and the trailing end of the blanket length straight and parallel to each other, in the assembled state, the two side edges within the manufacturing tolerances run exactly in the circumferential direction of the associated printing cylinder. The blankets of Drucktuchsets are accordingly rectangular. The blanket set preferably comprises a plurality of blankets of the first nominal width and a plurality of blankets of the second nominal width. Conveniently, it comprises at least as many blankets of the two different widths that with the blankets of the set a pair of printing cylinders, namely a printing cylinder and the impression cylinder, over each of the entire width of the cylinder usable for printing and over each almost the entire circumference with the blankets of the set can be occupied. For example, for a six-page press, the set advantageously comprises at least three blankets of the first width and three blankets of the second width to support at least one pair of printing cylinders, each with three blankets axially adjacent to each other and extending almost over the entire circumference of the cylinder.

Advantageous features are also described in the subclaims and their combinations.

Figur 1

zwei vierseitenbreite Druckzylinder mit einer Anordnung von Drucktüchern nach dem Stand der Technik,

Figur 2

die vierseitenbreiten Druckzylinder der Figur 1 mit einer erfindungsgemäßen Anordnung von Drucktüchern,

Figur 3

zwei sechsseitenbreite Druckzylinder mit einer Anordnung von Drucktüchern nach dem Stand der Technik,

Figur 4

die Druckzylinder der Figur 3 mit einer erfindungsgemäßen ersten Anordnung von Drucktüchern und

Figur 5

die Druckzylinder der Figur 3 mit einer erfindungsgemäßen zweiten Anordnung von Drucktüchern.

In the following, exemplary embodiments of the invention will be explained with reference to figures. The features disclosed in the exemplary embodiments form each individually and in each combination of features the subject-matter of the claims and also the embodiments described above. Show it:

FIG. 1

two four-page wide printing cylinders with an arrangement of printing blankets according to the prior art,

FIG. 2

the four-page-wide printing cylinder the FIG. 1 with an inventive arrangement of printing blankets,

FIG. 3

two six-page wide printing cylinders with an arrangement of printing blankets according to the prior art,

FIG. 4

the impression cylinder the FIG. 3 with a first arrangement of blankets according to the invention and

FIG. 5

the impression cylinder the FIG. 3 with a second arrangement of blankets according to the invention.

FIG. 1 shows a first pressure cylinder 1 and a second pressure cylinder 2, which together a pressure gap 3 for a between the pressure cylinders 1 and 2 form continuous paper web, the impression cylinder 1 and 2 in FIG. 1 are offset from each other and the pressure nip 3 is therefore open. The printing cylinders 1 and 2 are blanket cylinders of an offset, preferably wet offset, working web-fed rotary printing press preferably for newspaper printing. The paper web is printed on both sides in the printing nip 3.

The printing cylinders 1 and 2 are in a conventional manner with blankets 4, for example, blankets, occupied. The impression cylinders 1 and 2 are each four pages wide, i. The usable for printing bale is each so wide that the printing cylinder 1 and 2 axially next to each other four printed pages, preferably in the newspaper format, can print on the web. The printing cylinders 1 and 2 are each divided into two axially juxtaposed, immediately adjacent printing sections each having a width P, i. P corresponds to the width of two printed pages. The printing sections adjoin one another in the circumferential direction along an imaginary dividing line T. The width P of each of the printing sections is twice a printed page, i. it corresponds to a double page.

On each of the printing cylinders 1 and 2, two blankets 4 are arranged. The printing blankets 4 each have an axial width A which corresponds to the axial width P plus, depending on an oversize a. The excess a may be, for example, 3 mm. The printing blankets 4 abut one another along the dividing line T and each form a gap 10 around the respectively associated printing cylinder 1 or 2 radially over the dividing line T. The gap 10 of the printing cylinder 1 is arranged axially at the same height as the gap 10 of the printing cylinder 2 , so that the two columns 10 roll upon each other in a rotary drive of the printing cylinder 1 and 2 and thus in the printing operation on the passing therebetween web. The blankets 4 as such and their arrangement relative to each other corresponds to the prior art.

FIG. 2 shows the pair of impression cylinders 1 and 2 of FIG. 1 , but with inventively arranged blankets 5, in the embodiment blankets. The width P of the printing sections of the printing cylinders 1 and 2 and the axial position of the printing sections have compared to the arrangement of FIG. 1 not changed. The Division line T runs at each of the impression cylinders 1 and 2 in the axial center about the axis of rotation. The blankets 5 each have the same width B. The width B corresponds to the printing section width P plus an excess of a few millimeters, for example 5 mm. On each of the printing cylinders 1 and 2, two such printing blankets 5 are arranged axially next to one another and each encompassing almost the entire circumference of the associated printing cylinder 1 or 2. However, the two blankets 5 of the printing cylinder 1 are not exactly axially at the same height as the respective opposite, rolling in the printing blanket 5 of the printing cylinder 2 is arranged. Each of the blankets 5 of the printing cylinder 1 has a small axial offset to the cooperating blanket 5 of the printing cylinder 2.

The blankets 5 of the printing cylinder 1 are offset from the dividing line T of the printing cylinder 1 to the one end face of the printing cylinder 1, while the blankets 5 of the printing cylinder 2 are offset from the dividing line T to the opposite end side. The offset of the blankets 5 to the respective division line T is in FIG. 2 denoted by "c". Accordingly, the blankets 5 of the printing cylinder 1 abut one another along a first gap 10a offset by c to the dividing line T and the blankets 5 of the printing cylinder 2 along a second gap 10b also offset by c toward the other end side. The axial offset of the two columns 10a and 10b relative to each other is thus 2c. With "e" and "d" are in FIG. 2 the axially outer projections of the blankets 5 to the respective associated printing section of the printing cylinder 1 or 2 denotes. If the offset c of the column 10a and 10b calculated on the respective division line T, for example, 2 mm, the offset of the gaps 10a and 10b relative to each other is 4 mm, the supernatant d is in the example mentioned oversize of 5 mm 7 mm and the Overhang e on the other side is 3 mm. The offset c to the respective division line T or the offset 2c of the column 10a and 10b to each other is so small that the gaps 10a and 10b outside the sentence mirror, ie the print image to be transferred, the columns 10a and 10b are axially adjacent next printed pages ,

The transitions between the axially juxtaposed Drucktüchem 5 may be sealed with a suitable mass as in the other embodiments.

FIG. 3 shows two six-page-wide impression cylinder 11 and 12, which together form a pressure nip 3 for a passing between the printing cylinders 11 and 12, the paper web. The printing nip 3 is open, ie the printing cylinders 1 and 2 each occupy a parked position from the web. The printing cylinders 11 and 12 each have an axial bale width which corresponds to the width of six print pages which can be printed axially next to one another on the web, for example newspaper pages. The printing cylinders 11 and 12 are divided into three axially juxtaposed printing sections per width P. The dividing line between each two adjacent pressure sections is again denoted by T. On each of the printing cylinders 11 and 12, three printing blankets 6 of the width C are arranged axially next to one another. The arrangement of the blankets 6 is symmetrical in the axial direction, so that the column 10 formed between each two Drucktüchem 6 of the printing cylinder 11 roll on corresponding columns 10 of the printing cylinder 12 when the printing cylinder 11 and 12 are rotated. When using the term "rolling" is again neglected that in the printing operation, the web passes through the printing nip 3, so that the printing cylinders 11 and 12 do not roll on each other directly, but on the web to each other.

FIG. 4 shows the same pressure cylinder 11 and 12, but with inventively arranged blankets 7, preferably blankets. The blankets 7 of the two printing cylinders 11 and 12 each have the same width D and span the respective printing cylinder 11 or 12 almost over its entire circumference. The blankets 7 may be arranged on the respective printing cylinder 11 or 12 with respect to their leading and trailing ends in an axial alignment, for example in a single continuous clamping channel, or, more preferably, be offset in the circumferential direction to each other. Thus, for example, the leading and trailing ends of the two outer blankets 7 may be arranged in an axial alignment, while the two ends of the central blanket 7 in contrast offset in the circumferential direction by 180 ° are. Also preferred alternative arrangements with respect to the circumferential direction are shown in FIG PCT / EP2006 / 005754 described.

The width D of the blankets 7 corresponds to the width P of the respective associated printing section plus an excess h of a few millimeters, for example 4 mm. The blankets 7 of the printing cylinder 11 are compared to the axially symmetrical arrangement of FIG. 3 each offset axially to the same end face of the printing cylinder 11. The axial offset corresponds to half the excess h. The blankets 7 of the printing cylinder 12 are offset to the opposite end side also by h / 2 compared to the axially symmetrical arrangement. In this way, an axial offset h corresponding to the excess is obtained between the gaps 10a of the printing cylinder 11 and the respectively next adjacent gap 10b of the printing cylinder 12.

FIG. 5 shows for the six-page printing cylinder 11 and 12 of the FIGS. 3 and 4 A second embodiment of the arrangement of blankets. Printing blankets 8 and 9 are used in two different widths E and F. The width E of the printing blankets 8 corresponds to the width P of the respective associated printing section. Compared to the uniform printing blankets 7 in the embodiment of FIG. 4 the narrow blankets 8 thus have an undersize. This undersize is compensated by a correspondingly greater width F of the blankets 9. The width F corresponds to the width P of the respective associated printing section plus a correspondingly larger oversize of, for example, 8 mm, that is to say an oversize 2h. The blankets 8 and 9 are arranged on the printing cylinders 11 and 12 in the axial direction in each case in an alternating sequence. On the printing cylinder 11, a narrower blanket 8 is disposed between two wider blankets 9, while on the printing cylinder 12, a wider blanket 9 is disposed between two narrower blankets 8. The blankets 8 and 9 span the respective impression cylinder 11 and 12 as in the other embodiments over almost the entire circumference. With regard to the arrangement of the leading and trailing ends of the blankets 8 and 9 applies to the embodiment of the FIG. 4 Said in the same way.

The respective middle blanket 8 or 9 is arranged axially centrally on the respective printing cylinder 11 or 12. Accordingly, the two outer blankets 8 or 9 are arranged axially asymmetrically. In the printing cylinder 11, the gaps 10a formed between each two axially juxtaposed printing blankets 8 and 9 therefore extend on the respective division line T. The gaps 10b of the printing cylinder 12 each have an axial offset h relative to the gaps 10a and the dividing lines T. half excess of the wider blankets 9 corresponds. As already in the embodiment of FIG. 4 the axial offset h between the next adjacent columns 10a and 10b is the same. He is also in the embodiment of FIG. 5 4 mm by way of example.

Each of the printing cylinders 1 and 2 and the printing cylinders 11 and 12 transmits a printed image obtained from a respectively subsequent forme cylinder to the web. Each of the forme cylinders has an inking unit and, if the press works in wet offset, a dampening unit downstream. The two printing units of the printing cylinder 1 and 2 on the one hand and the printing cylinder 11 and 12 on the other hand together form a printing unit having in a side view, for example, the shape of a "V" or an inverted "V". Preferably, the printing machine comprises a plurality of such printing units, which are arranged one above the other in a printing tower, so that the web can be guided at least substantially vertically through the printing nips 3 of the printing tower and printed on both sides in multi-color printing columns 3. In such a printing tower, at least four such printing units are preferably arranged one above the other, so that the web can be printed on both sides in four colors in the printing tower. The printing press expediently comprises a plurality of such printing towers, in each of which a web can be printed on both sides in multiple colors.

Reference numerals:

1

pressure cylinder

2

pressure cylinder

3

nip

4

blanket

5

blanket

6

blanket

7

blanket

8th

blanket

9

blanket

10

Blanket gap

10a

Blanket gap

10b

Blanket gap

11

pressure cylinder

12

pressure cylinder

A, ..., F

Nominal width of the printing blanket

P

Width of the printing section

T

dividing line

Claims (15)

1. A rotary printing machine, comprising:

   a) a first printing cylinder (1; 11);

   b) printing blankets (5; 7; 8, 9) which are arranged axially next to each other on the first printing cylinder (1; 11) and between which a first gap (10a) is formed which extends in the circumferential direction;

   c) a second printing cylinder (2; 12) which together with the first printing cylinder (1; 11) forms a printing gap for a web;

   d) and printing blankets (5; 7; 8, 9) which are arranged axially next to each other on the second printing cylinder (2; 12) and roll off on the printing blankets (5; 7; 8, 9) of the first printing cylinder (1; 11) and between which a second gap (10b) is formed which extends in the circumferential direction,
   characterised in that

   e) the gaps (10a, 10b) are axially offset with respect to each other, such that the first gap (10a) rolls off on one of the printing blankets (5; 7; 8, 9) of the second printing cylinder (2; 12), and the second gap (10b) rolls off on one of the printing blankets (5; 7; 8, 9) of the first printing cylinder (1; 11).
2. The rotary printing machine according to the preceding claim, characterised in that the printing blankets (5; 7; 8, 9) are rectangular.
3. The rotary printing machine according to any one of the preceding claims, characterised in that the printing cylinders (1, 2; 11, 12) comprise printing sections (P), axially next to each other, for printing at least one printing side - preferably, exactly two printing sides - each, and in that at least two of the printing blankets (5; 7; 8, 9) of at least one of the printing cylinders (1, 2; 11, 12) each exhibit an axial centre which is axially offset with respect to an axial centre of the respectively assigned printing section (P).
4. The rotary printing machine according to any one of the preceding claims, characterised in that the printing cylinders (1, 2; 11, 12) each exhibit an axial width of a number of printing sides, and the printing blankets (5; 7; 8, 9) of at least one of the printing cylinders (1, 2; 11, 12) each have a width (B, D, E, F) which at least substantially corresponds to a multiple of the width - preferably, twice the width - of one of the printing sides.
5. The rotary printing machine according to any one of the preceding claims, characterised in that the printing blankets (5; 7; 8, 9) of at least one of the printing cylinders (1, 2; 11, 12) each extend over at least substantially the entire circumference of said printing cylinder.
6. The rotary printing machine according to any one of the preceding claims, characterised in that the first gap (10a) is offset by at least 1 mm and at most 20 mm with respect to the second gap (10b) or the nearest of a number of second gaps (10b).
7. The rotary printing machine according to any one of the preceding claims, characterised in that the printing blankets (8, 9) comprise a first printing blanket (8) with a first width (E) and a second printing blanket (9) with a second width (F) which differs from the first width (E).
8. The rotary printing machine according to the preceding claim, characterised in that the printing blankets (8, 9) with the mutually differing widths (E, F) are arranged on the same printing cylinder (11, 12).
9. The rotary printing machine according to any one of the preceding two claims, characterised in that the first printing blanket (8) is arranged on the first printing cylinder (11) and the second printing blanket (9) is arranged on the second printing cylinder (12), and the printing blanket (8) with the smaller width overlaps the second printing blanket (9) over at least the majority of its width (E).
10. The rotary printing machine according to any one of the preceding three claims, characterised in that at least two first printing blankets (8) and one second printing blanket (9) are arranged on at least one of the printing cylinders (11, 12).
11. The rotary printing machine according to any one of the preceding four claims, characterised in that the printing blankets (8, 9) with the mutually differing widths (E, F) are arranged on the first printing cylinder (11) in an axially alternating order.
12. The rotary printing machine according to the preceding claim, characterised in that the printing blankets (8, 9) with the mutually differing widths (E, F) are arranged on the second printing cylinder (12), axially alternating in reverse order, such that a first printing blanket (8) arranged on the first printing cylinder (11) axially overlaps a second printing blanket (9) arranged on the second printing cylinder (12) over a predominant part of its width (E).
13. The rotary printing machine according to any one of the preceding six claims, characterised in that printing blankets (8, 9) with mutually differing widths (E, F) are arranged on each of the two printing cylinders (11, 12).
14. The rotary printing machine according to any one of claims 1 to 11, characterised in that the printing blankets (5; 7) of at least one of the printing cylinders (1, 2; 11, 12) each exhibit the same width (B; D).
15. The rotary printing machine according to any one of claims 1 to 6 or according to claim 14, characterised in that the printing blankets (5; 7) each have the same width (B; D), and the printing blankets (5; 7) of the first printing cylinder (1; 11) are axially offset with respect to the printing blankets (5; 7) of the second printing cylinder (2; 12).

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