Printing – Printing members – Plate mountings
Reexamination Certificate
2001-08-27
2004-06-15
Hirshfeld, Andrew H. (Department: 2854)
Printing
Printing members
Plate mountings
C101S415100, C101S378000, C101S409000
Reexamination Certificate
active
06748862
ABSTRACT:
BACKGROUND OF THE INVENTION
Field of the Invention
The invention lies in the printing technology field. More specifically, the invention relates to a device for adjusting at least one register element in a printing machine, having an upper clamping rail, to which the register elements are fixed, and a clamping element which co-operates with the upper clamping rail. The invention further pertains to a corresponding method.
In addition, the invention relates to a method of adjusting at least one register element in a printing machine.
Devices and methods which can be implemented therewith of the type addressed here are known from European patent EP 0 596 337 B1. There, the clamping rail, in particular of a sheet-fed offset printing machine, is used to fix a printing plate to an associated plate cylinder. Because of tolerances which become established and are not desired in the printing machine and therefore also on the plate cylinder, it is necessary to provide a positional adjustment of the register elements (register pins) in relation to a fixed printing-plate leading edge. European patent EP 0 596 337 B1 discloses the practice of adjusting the position of the register elements in each case in relation to the clamping rail by means of an appropriately designed fixing mechanism. In this way, unavoidable inaccuracies or play on the plate cylinder of the printing machine, between the clamping rail and the printing plate to be fixed, are compensated for, so that a printing plate to be clamped can be fixed to the plate cylinder in a precise and correct manner by means of the register elements operatively connected to the clamping rail.
It is additionally known, in order to adjust the position of register elements, to adjust the position of the entire clamping rail—comprising an upper clamping rail and a lower clamping strip co-operating with the latter—released from the plate cylinder together with the register elements. Since the clamping rail is operatively connected to the plate cylinder by means of a relatively large number of clamping means (clamping screws), loosening these clamping means for the subsequent positional adjustment of the clamping rail with register elements is disadvantageously time-consuming and complicated.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a device adjusting at least one register element in a printing machine and a corresponding method, which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which permits precise and rapid positional adjustment of the register elements, without having to loosen the operative connection between the register elements and the upper clamping rail for this purpose.
With the foregoing and other objects in view there is provided, in accordance with the invention, a device for adjusting a register element in a printing machine. The device comprises:
an upper clamping rail and a register element fixed to the upper clamping rail, wherein the upper clamping rail is movably disposed in a guide and fixable in position for adjusting the register element; and
a clamping element co-operating with the upper clamping rail.
In other words, the above objects are achieved with a device the other clamping rail of which can be moved in a guide and fixed in position in order to adjust the register element. In this case, the guide is preferably designed in such a way that, in every possible operating position of the clamping rail, it can compensate for the blocking forces which are established in order to fix a printing plate to the plate cylinder. The adjustment of the respective register element is therefore carried out by means of a suitable relative movement of the upper clamping rail relative to the plate cylinder, the corresponding register element being fixed in a stable position even during the adjustment operation on the upper clamping rail. By means of an upper clamping rail which is always guided during the adjustment operation, it is possible, by using an adjusting means which is suitably designed and operatively connected to the upper clamping rail, to achieve rapid and defined adjustment of the register element. At the same time, it is not necessary to detach the upper clamping rail completely from the plate cylinder in order to adjust the register element, instead, because of the guidance provided for the clamping rail, there is also the possibility to deform or to bend the latter elastically in an adjustment direction by means of a suitable adjusting means in order to achieve a positioning of the respective register element, which is established appropriately, relative to the printing plate to be fixed or to be clamped to the plate cylinder. After assuming a desired operating position of the elastically deformed clamping rail or of the associated register element, the clamping rail can be fixed in position on the plate cylinder by means of suitable clamping or tensioning means. In accordance with an added feature of the invention, the guide is advantageously a sliding guide, and the position of the upper clamping rail can be adjusted by means of an adjusting device in a sliding direction corresponding to the adjustment direction of the register element. A sliding guide can be implemented relatively simply in production terms and is particularly suitable to compensate for forces which are established in order to fix a printing plate to the plate cylinder and are radial in relation to the plate cylinder, precise guidance of the upper clamping rail on the plate cylinder being ensured at the same time. This makes it possible, by means of a defined positional adjustment of the clamping rail, while actuating a suitably designed adjusting device, to obtain rapid and correct adjustment of the respective register element.
According to a preferred embodiment, the adjusting device has at least one mechanical adjusting element for producing an adjusting force acting on the upper clamping rail. In this case, the mechanical adjusting element provided can be a setting screw suitably operatively connected to the upper clamping rail, a wedge, an eccentric pin or the like, by means of which adjustment of the upper clamping rail in tangential direction with regard to the plate cylinder can be achieved. A mechanical adjusting element of this type is preferably operated manually.
According to a further alternative embodiment, the adjusting device has at least one electrical adjusting element for producing an adjusting force acting on the clamping rail. In this case, for example, the use of bundled piezoelectric actuators can be provided, by means of which an electrically triggerable introduction of force into the upper clamping rail in order to adjust the position of the same can be implemented. In this case, electrically operated adjusting elements are particularly suitable for the automated adjustment of the respective register element by means of a suitable, preferably central, control unit.
Clamping or tensioning means are advantageously provided to fix the position of the clamping rail. Clamping or tensioning means of this type, serving to lock or fix the deformed clamping rail, or the clamping rail displaced without elastic bending, can be designed as clamping screws, for example. In addition, it is possible to implement the positional fixing of the clamping rail by means of electrically operated clamping or tensioning means, so that automated fixing of the position of the clamping rail by means of a preferably central control unit is also possible.
The device is advantageously operatively connected to a central control unit. By means of a central control unit, by using electrically operated adjusting elements and positional fixing means for the clamping rail, automated and controlled adjustment of the respective register element can be carried out.
According to a further, alternative embodiment, the clamping rail comprises a multiplicity of relatively mobile part segments, each of which contains at least one register element. This makes i
Becker Ludwig
Frankenberger Eckart
Weber Werner
Evans Andrea H.
Greenberg Laurence A.
Heidelberger Druckmaschinen AG
Hirshfeld Andrew H.
Mayback Gregory L.
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