EP0554763A1 - Arrangement for fixing the lower layer of a double-ply covering for a printing cylinder in rotary printing machine - Google Patents

Abstract

In an arrangement for fixing the lower layer (21) of double-ply coverings (8, 21) for impression cylinders (1), the object consists in fixing the lower layer (21) of variable thickness with little space and minimal expenditure. According to the invention, this is achieved in that the end wall (9) of the cylinder gap (2) has attachments in the form of pins (11, 12) with holding-down devices (16) which are arranged between them and are operatively connected via holes (23) to the beginning of the lower covering (21). No additional components are required for this arrangement, and it can also be used in rotary printing machines without bearing rings.

Description

The invention relates to an arrangement for holding the lower layer of two-layer elevators for printing cylinders of rotary printing presses according to the preamble of claim 1.

It is known to arrange one or more layers of paper under the rubber or printing blankets in order to make the diameter of the cylinders variable for printing reasons.

According to DD-PS 1 28 886 a device for attaching the bottom layer or the bottom layers of multi-layer covers for transfer and offset cylinders is known, the lower blanket layer being clamped by a trapezoidal strip by means of spring force against the side surface of the cylinder tensioning channel.

The disadvantage here is that the bar must be adjusted by hand using a wrench. Furthermore, the upper layer of printing blanket must be fed through a slot in the bar of a tensioning shaft, which, in addition to increased effort and also due to the arrangement of the slot, results in a weakening of the cross section of the bar.

Furthermore, according to EP-PS 0 070 378, a device for holding the lower elevator of a two-part elevator of the outer surface of a printing cylinder in printing machines is known, in which a holding rail located in the channel of the printing cylinder with a circular cross-section is arranged, which receives the lower elevator. The holding rail is inserted into the centering holes of the bearer rings by means of pins.

The disadvantage of this device is that the holding rail is complex to manufacture, tools for actuating the holding bolts for the lower elevator are required and the holding rail requires a relatively large amount of space in the cylinder channel.

Furthermore, at the o. G. Device disadvantageous that the entire holding rail must be operated with all adjustable holding elements if the thickness of the lower elevator must be varied for printing reasons.

In addition, it is disadvantageous that the holding rail is held laterally in bearer rings. This can lead to the automatic release of the support in the centering bores of the bearer rings during operation, for example with a reduced number of printing inks, if the holding rail is held without an elevator but is not properly engaged.

Finally, the use of such retaining strips in bearerless printing machines is only possible with an additional mounting on the front side.

The invention has for its object to provide a space-saving and can be operated with little effort in varying the elevator thickness, safe arrangement for holding the lower layer of two-layer elevators, also for bearerless printing cylinders, for printing presses.

According to the invention, this object is achieved by the characterizing part of patent claim 1.

The advantages of the arrangement according to the invention are, in particular, that little space is required in the cylinder channel as a result of the mounting of the lower elevator without holding bars and that the arrangement is adequately secure, since no additional components are required or, if a inking or printing unit is not used, also an expansion is not required.

Furthermore, the arrangement according to the invention can also be used in rotary printing machines without bearer rings.

Fig. 1

den Querschnitt durch einen Druckzylinder, aus dem die Lage der erfindungsgemäßen Anordnung hervorgeht;

Fig. 2

die Ansicht A auf die erfindungsgemäße Halteanordnung an der Kanalseitenwand in axialer Richtung gemäß Fig. 3, jedoch ohne Gummituch und ohne Unterlagebogen;

Fig. 3

den Schnitt III - III nach Fig. 2 in vergrößerter Darstellung;

Fig. 4

einen Längsschnitt durch den Anfang des unteren Aufzuges.

The invention is explained in more detail below using an exemplary embodiment. The associated drawings show:

Fig. 1

the cross section through a pressure cylinder, from which the position of the arrangement according to the invention emerges;

Fig. 2

view A of the holding arrangement according to the invention on the channel side wall in the axial direction according to FIG. 3, but without a rubber blanket and without a supporting sheet;

Fig. 3

the section III - III of Figure 2 in an enlarged view.

Fig. 4

a longitudinal section through the beginning of the lower elevator.

1 shows a section through a pressure cylinder 1, from which the position of the arrangement according to the invention can be seen. The pressure cylinder 1 has two tension shafts 3 arranged in the cylinder channel 2; 4, in a slot 6; 7 hold the upper elevator held in a bar in the form of a rubber blanket 8. The tension shafts 3; 4 can be rotated and locked by known technical means.

FIG. 3 shows the detail X of FIG. 1 with the section along the line III-III according to FIG. 2.

The rubber blanket 8 clamped in the tensioning shaft 3 is in the tensioning position, which is marked with I. If the tension shaft 3 is moved by the angle of rotation α, the rest position of the tension shaft 3 is reached, which is represented by the broken line II.

On the end wall of the cylinder channel 2 9 fastenings in the form of pins 11 are perpendicular to the surface of the end wall; 12 embedded, for example in holes can be glued. The pins 11; 12 are at their ends protruding from the end wall 9 of the printing cylinder 1 with bevels 13; 14 provided. Between the pins 11; 12 is a hold-down device 16 extending in the axial direction by means of countersunk screws 17; 18 attached, which has a hook-shaped retaining lug 19.

The lower elevator, which can be made of multi-layer paper sheets, is designated by a total of 21. The lower elevator 21 is aligned on one side on a stop pin 22 and has holes 23; into which the pins 11; 12 intervene. Accordingly, the lower elevator 21 is laterally by means of holes 23 on the pins 11; 12 held and held in the middle by the hold-down device 16 with the holding lug 19.

To remove the rubber blanket 21, the tensioning shaft 3 is brought into the rest position I according to FIG. 3. The arrangement of recesses 24; 26 in the end wall 9 makes it easier to remove the lower elevator 21.

The lower elevator is usually constructed in several layers, preferably in such a way that the outermost layers are formed in one piece, ie the beginning 27 of the lower elevator 21 is pocket-shaped. Now, depending on the printing requirements according to FIG. 4, additional layers 28 can be inserted into the beginning 27, which - as shown in broken lines in FIG. 2 - have chamfered corners, so that the holes 23 are omitted and thus the lower elevator 21 is not removed must be to change the number of additional sheets 28.

Parts list

1

Pressure cylinder

2nd

Cylinder channel

3rd

Tension shaft

4th

Tension shaft

5

-

6

slot

7

slot

8th

Rubber blanket

9

End wall (2)

10th

-

11

pen

12

pen

13

bevel

14

bevel

15

-

16

Hold-down

17th

Countersunk screw

18th

Countersunk screw

19th

Holding nose

20th

-

21

Elevator, lower

22

Stop pin

23

hole

24th

Recess

25th

-

26

Recess

27

Early (21)

28

Additional location

I.

Rest position

II

Clamping position

A

view

X

Detail

α

Angle of rotation

Claims (7)

Arrangement for holding the lower layer (21) of two-layer elevators (8; 21) for printing cylinders (1) of rotary printing machines, the lower layer (21) being fastened to the outer surface of the printing cylinder (1) and in the cylinder channel (2) characterized in that the end wall (9) of the cylinder channel (2) has fastenings in the form of pins (11; 12) with hold-down devices (16) arranged between them, which with the beginning (27) of the lower elevator (21) via holes (23) are in operative connection. Arrangement according to claim 1, characterized in that the lower elevator (21) is constructed in multiple layers and that the outer layers (27) of the lower elevator (21) are formed in one piece. Arrangement according to claims 1 and 2, characterized in that the inner layers (28) of the lower elevator (21) at the beginning (27) are trapezoidal. Arrangement according to claims 1 to 3, characterized in that the pins (11; 12) have bevels (13; 14) at their ends. Arrangement according to claims 1 to 4, characterized in that the lower elevator (21) can be aligned laterally by a stop pin (22) arranged in the end wall (9) of the cylinder channel (2). Arrangement according to claims 1 to 5, characterized in that the end wall (9) of the cylinder channel (2) has recesses (24; 26). Arrangement according to claims 1 to 6, characterized in that the hold-down device (16) has a hook-shaped holding lug (19).

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