GB2307448A

GB2307448A - Adjustment device for printing unit cylinders

Info

Publication number: GB2307448A
Application number: GB9624021A
Authority: GB
Inventors: Georg Hartung; Ulrich Jung; Manfred Herold
Original assignee: MAN Roland Druckmaschinen AG
Current assignee: Manroland AG
Priority date: 1995-11-22
Filing date: 1996-11-19
Publication date: 1997-05-28
Anticipated expiration: 2016-11-19
Also published as: JP2994283B2; JPH09174805A; GB2307448B; DE19543494C1; GB9624021D0; FR2741294B1; FR2741294A1

Description

2307448 ADJUSTMENT DEVICE FOR PRINTING UNIT CYLINDERS This invention

relates to an adjustment device for printing unit cylinders, e.g. blanket or printing forme cylinders in printing or varnishing units in sheet offset printing presses.

Blanket cylinders in the printing units of sheet offset printing presses are conventionally mounted via eccentric bearings in the side frames of the press. By swivelling these, the position of the blanket cylinder is adjustable with respect to the impression and plate cylinders cooperating therewith. By such swivelling of the eccentric bearing, it is possible both to throw on and off the blanket cylinder with respect to the sheet guiding impression cylinder and also relative to the plate cylinder cooperating with the blanket cylinder. In such cases, there cooperates with the eccentric bearing a so- called two-stage print switching actuation device, so that in a first switching stage, the blanket cylinder is set off from the impression cylinder and remains set against the plate cylinder just as before, and in a second stage the blanket cylinder is set off from both cylinders.

2 Furthermore, it is known to instal after the print switching device an adjusting device as a further operational device for adjusting to the thickness of the material to be printed or to put them in series, so that by the adjustment device the eccentric bearings are swivelled in each case through the same angular amount, which effects a parallel adjustment of the axis of the blanket cylinder with respect to the axis of the impression cylinder carrying the sheet. Also it is known to arrange with respect to each eccentric bearing an adjusting device which is supported fixed with respect to the frame so that the cylinder, on simultaneous adjustment of the adjusting devices, is adjustable both parallel and also obliquely with reference to the cylinder cooperating with it. Such adjusting devices find use particularly in the case of plate cylinders of offset printing presses. The plate cylinder can accordingly be set against the blanket cylinder in such a fashion that even line pressure is present across the format width.

The last-noted arrangement of an adjusting device in each case with respect to an eccentric bearing of an adjustable cylinder, however, has the disadvantage that for a parallel adjustment of the cylinder with respect to the cylinder cooperating with it (for example plate cylinder with respect to blanket cylinder or a print forme cylinder in a varnishing unit with respect to the impression cylinder), both adjusting devices must be adjusted either simultaneously or successively in each case to the same value. As advantageous in this connection, there is to be seen that the cylinder can be adjusted on one side (skewed) over a very broad range with respect to the cylinder cooperating with it.

3 Precisely in the case of varnishing units installed downstream of printing units in sheet offset printing presses in which the one print forme in the form of a blanket or a cylinder carrying a relief printing plate cooperates with an impression cylinder, on account of tolerances of the thickness of the material to be printed across the format width, even stronger tolerances of the relief printing plate serving as a print forme as well as a compressibility dependent upon the subject, corresponding adjustments are necessary in order across the format width to achieve an even print or varnishing result. If, however, a cylinder which is carried adjustably via in each case an adjustment device arranged relative to an eccentric bearing in accordance with the previously indicated type is adjusted past a predetermined amount obliquely with respect to the axis of the cylinder cooperating therewith, then immediately at high running operation, bearing damage can arise. The reason for this is founded in that the eccentric bearing carrying the cylinder via its trunnions only enables a given tilting of the trunnion with respect to the corresponding bearing. This means that with an adjusting device arranged in each case at one end of the cylinder, by means of which the cylinder should be adjustable additionally over a large range parallel to another cylinder, additional measures need to be taken so that too strong differences in the respective adjustments are avoided.

From DE 91 94 151, a device for adjusting the axial distance between the blanket cylinder and impression cylinder of an offset sheet printing press is known in which a central pressure adjustment acts via a rod shiftable along the press on the individual eccentric 4 - bearing pairs of the respective blanket cylinders. For common swivelling of the eccentric bearings in each case of a blanket cylinder, the eccentric bearings are linked with one another in each case via a retraction shaft. The linkage of the push rods to the respective eccentric bearings takes place in this connection via intermediately placed adjusting devices so that the eccentric bearings are adjustable relative to the longitudinally shiftable push rod. Arranged with respect to each blanket cylinder in this connection there is furthermore a print switching unit which is constructed in the fashion of a knee lever drive and which makes possible the two-stage setting on and off of the blanket cylinder with respect to the impression and plate cylinders. By the pressure adjustment which can be actuated at the controls of the printing press and the push rod, the blanket cylinders in the individual print units are adjustable in common to a value so that a preset distance between the axes of the blanket cylinders is achieved (adjustment for thickness of material to be printed).

From DE 40 13 075 Cl, a device is known for print set on and off of a blanket cylinder in the printing unit of an offset sheet printing press. Here two pneumatic cylinders work via a link on a knee lever drive and a retraction shaft, which connects with one another both of the eccentric bearings carrying the blanket cylinder. Furthermore, arranged relative to the knee lever, there is a further adjustment device for the thickness of the material to be printed, by means of which the blanket cylinder is adjustable with respect to the impression cylinder corresponding to the thickness of the material to be printed. Since both the adjustment device for the thickness of the material to be printed and also the pneumatic cylinder act on the retraction shaft, and this retraction shaft swivels both eccentric bearings respectively through the same angular amount, by means of this device, only a parallel adjustment of the blanket cylinder with respect to the impression cylinder is possible. A one-side stronger setting of the blanket cylinder with respect to the impression cylinder is not provided for here.

The present invention seeks to develop an adjusting device for printing unit cylinders which, while avoiding the previously noted disadvantages, enables adjustment of the axial distance of the printing unit cylinders with respect to the cylinders cooperating therewith, both in parallel and also on one side only (skew adjustment), and further enables such adjustment to occur even when the press is running. In particular, by means of the adjustment device, it should be guaranteed that too strong skewing or oblique setting of the axis of the cylinder to be adjusted with reference to the cylinder cooperating with it should be prevented.

The adjusting device in accordance with the invention can in this connection be used both on the blanket cylinder and plate cylinders of offset printing units and also of print forme cylinders of varnishing units and other finishing devices. By using the invention, it is guaranteed that a printing unit cylinder cooperating with another cylinder is adjustable relative to this both in parallel and also obliquely to one side, wherein both the parallel and also the skew adjustment of the cylinder axles can be undertaken during machine running. In the case of the actuation device acting on both eccentric bearings, this can be a manually or motor adjustable adjusting device for adjusting to the thickness of the material to be printed, in order to deal with a one or several stage working print switch unit for forwarding and retracting the cylinders and also of a corresponding series switching of a device for the thickness of the material to be printed and print switching. Important in this connection is that between the actuation device acting on both eccentric bearings, an adjustment device is arranged between one eccentric bearing and the actuation device by means of which the one eccentric bearing can be adjusted with reference to the second eccentric bearing through a predetermined angular amount, so that the axis of the impression cylinder can be adjusted obliquely with respect to the axis of the cylinder cooperating with it. The adjustment region of the adjusting device installed intermediately between the actuation device and one of the eccentric bearings is matched in this connection with the maximum possible tiltability of the trunnion of the cylinder within the eccentric bearing carrying this.

The invention is illustrated, by way of example, with reference to an embodiment of the invention shown diagrammatically in the accompanying drawings, in which:

Figures 1 and 2 show diagrammatically an adjusting device in accordance with the invention in the print on or print off position respectively, Figure 3 shows in greater detail a lever mounted swivellably on a retraction shaft with a slide block longitudinally displaceable in a groove therein, Figure 4 diagrammatically illustrates the mounting and the corresponding possibility of adjustment of a printing unit cylinder, and Figure 5 shows the sequential arrangement of print setting and print switching devices.

Referring to the drawings, Figure 4 shows diagrammatically a first cylinder 14 which needs to be adjusted with respect to a cylinder 15. Cylinder 14 is supported at each end via an eccentric bearing 1 receiving a trunnion 2. By swivelling the eccentric bearings 1 by the same or differing angular amounts, there thus arises accordingly a parallel or oblique setting of the axis of the cylinder 14 with reference to the axis of the cylinder 15. The eccentric bearings 1 and the trunnions of the cylinder 15 cooperating with the cylinder 14 are in this connection swivellably/rotatably mounted in not illustrated frame walls of the printing or varnishing unit.

Figure 5 shows in principle the actuation device operating in common on the eccentric bearing 1 of the cylinder 14 which, in this exemplary embodiment, consists of a print switch device as well as an adjusting device for the thickness of the material to be printed. Also here the trunnions 2 of the adjustable cylinder 14 (itself not shown in Figure 5) are carried in each case via an eccentric bearing 1 swivellable in the frame wall. Both eccentric bearings 1 are, in this connection, connected in each case via a link 3 with the swivellable end of a lever 4 set on the end of a retraction shaft 5. The arrangement illustrated in Figure 5 ig located, e. g., on the B side of the printing press. The retraction 8 shaft 5, which extends from the A to the B side of the printing press between the frame walls, has as well as lever 4 a second lever 6, the swivellable end of which i connected pivotally with the piston rod 7 of a working cylinder 8. By subjecting the working chamber of the working cylinder 8 to pressurised medium hydraulic), the piston rod 7 is moved so movement of the lever 6 installed on the retraction shaft 7 is transferred into a swivel movement of the retraction shaft 5 retraction shaft 5 now transfers for its (pneumatic, that the swivel B side of corresponding. The part, in each case via a link 3 on the A and B side, the swivel movement to the eccentric bearing 1.

The print switching device in accordance with Figure 5 accordingly consists of a working cylinder 8 as well as the piston rod 7 actuatable by subjection to pressure medium. The foot of the working cylinder 8 is pivotally connected in turn with a lever 9 which is swivellably mounted about an axis fixed with respect to the frame.. The lever 9 is extended with respect to its swivellable and fixed frame mounting by a further lever 10 to a ternary member, wherein at the end of this, a spindle nut 11 is pivoted. This spindle nut 11 is threaded on to a threaded spindle 12 which can be actuated by an adjustment drive 13. The adjustment drive 13 can in this connection be motor remote controlled or can be constructed manually operatable by means of an adjusting dial. By means of the adjustment drive 13, the adjustment of the eccentric bearing 1 respectively on the A and B side dependent upon the material to be printed takes place, so that in accordance with Figure 4, the cylinder 14 is adjusted in its distance parallel to the axis of the cylinder 15 cooperating with it. By correspondingly subjecting the working chamber of working cylinder 8 to pressure medium and by the consequently moved in or out piston rod 7, cylinder 14 can be set on and off with respect to cylinder 15 by swivelling of the eccentric bearings 1 on the A and B side. The working cylinder 8 can in this connection particularly be a socalled two-stage working cylinder. In accordance with the exemplary embodiment of the invention illustrated here, the arrangement according to Figure 5 shows the print switching unit as well as the adjusting unit for the thickness of the material to be printed, which is pivoted on the end of the retraction shaft 5 on the B side of the press.

is Figures 1 and 2 show the end of the retraction shaft 5 located on the oppositely lying A side of the press. The lever 16 acting via the link 3 on the eccentric bearing 1 on the A side is here mounted rotatably on the retraction shaft 5. The lever 16 mounted rotatably on the retraction shaft 5 has an entrainer 17 arranged relative to it, which is constructed like a lever and which is installed rotationally fast on the retraction shaft 5.

Rotatably mounted inset into the lever-like constructed entrainer 17 is a worm wheel 18, wherein the axis of the worm wheel 18 runs parallel to the retraction shaft 5.

The worm wheel 18 engages with a worm 19 likewise inset into the entrainer 17 and secured against axial shifting, which can be rotated via two joints 20 and a telescopic shaft 21 from an adjustment drive 22 fixed with respect to the frame. The adjustment drive 22 can, in this connection, be constructed with an adjustment dial provided with an adjusting scale or with an electric - motor.

The worm wheel 18 meshing with the worm 19 and inset into the entrainer 17 has on the side turned towards the lever 16 a pin 23 arranged eccentrically relative to the axis of the worm wheel 18 which, movable by rotation, penetrates into a corresponding bore of a slide block 24. The slide block 24 is slidably let into a groove 25 machined into the lever 16. The slide block 24 and the groove 25 in the lever 16 rotatably mounted on the retraction shaft 5 thus cooperate in the form of a straight line guide (Figure 3). By rotation of the worm 19 and accordingly rotation of the worm wheel 18, the lever 16 is swivelled with respect to the retraction shaft 5 via the pin 23 and the slide block 24, whereby this swivel movement is transferred via the link 3 on to the eccentric bearing 1 mounted on the A side. Accordingly, the eccentric bearing 1 shown in Figures 1 and 2 on the A side is adjustable through a given angular 20 amount with respect to the eccentric bearing on the B, side of the printing press (Figure 5) so that an oblique adjustment of the cylinder 14 with respect to the cylinder 15 cooperating therewith results (as shown in the lower part of Figure 2). The adjustment range of the adjusting drive 22 and accordingly the swivellability of the lever 16 with reference to the entrainer 17 on the retraction shaft 5 is, in this connection, set so that the cylinder 14 is adjustable obliquely with respect to the cylinder 15 over a maximum range provided.

In Figures 1 and 2, the eccentric bearing 1 on the A side together with the lever 16 as well as entrainer 17 on the retraction shaft 7 are illustrated both in the print on and also in the print off position, wherein Figure 1 - 11 corresponds to the print on position. The telescopic shaft 21 makes possible in this connection a change in distance between the joints 20 on carrying out the swivel movement.

12 -

Claims

CLAIMS is 1. An adjusting device for cylinders in the printing unit of

printing presses, particularly for blanket or printing forme cylinders in printing or varnishing units of sheet offset printing presses, wherein the cylinder is mounted at each end via an eccentric bearing such that swivelling the bearings enables adjustment of the position of the cylinder with respect to a further cylinder, the adjusting device comprising an actuation device for simultaneous swivelling of both eccentric bearings and, arranged relative to one eccentric bearing, and linked to an adjusting drive fast with respect to the framework, an adjustment means enabling one eccentric bearing to be swivelled with respect to the other eccentric bearing.
2. An adjusting device according to Claim 1 wherein the actuation device comprises a retraction shaft linking the eccentric bearing of the cylinder with one another and extending between frame walls of the printing or varnishing unit, and the adjustment means is arranged at one end of the retraction shaft.
3. An adjusting device according to Claim 2 wherein the retraction shaft is connected at one end via a first lever connected rotationally fast with the retraction shaft and a link with one eccentric bearing of the cylinder and at its other end via a second lever mounted rotatably with respect to the retraction shaft and a link with the other eccentric bearing, wherein the second lever is swivellable with respect to an entrainer set rotationally fast on the retraction shaft.
4. An adjusting device according to Claim 3 wherein in the entrainer there is arranged a worm wheel with a worm, wherein the worm wheel has an eccentric pin which engages in a bore of a sliding block movably let into a groove of the second lever.
5. An adjusting device according to any one of the preceding Claims and wherein the adjustment means is connected via a jointed shaft to an adjustment drive installed fixed with respect to the frame of the printing unit.
6. An adjusting device according to any one of the preceding Claims and wherein the actuation device comprises means for adjusting the cylinder dependent upon the thickness of the material to be printed with respect to a cylinder cooperating with it, as well as a print switching device for setting on and off a cylinder with respect to a cylinder cooperating therewith.
7. An adjusting device according to any one of the preceding Claims wherein the adjustment means includes means limiting the adjustment range to correspond to a maximum envisageable skew adjustment of the cylinder with respect to a cylinder cooperating therewith.
8. An adjusting device for use in adjusting the position of a cylinder in a printing unit substantially as hereinbefore described with reference to the accompanying drawings.