Printing – Press part or attachment
Reexamination Certificate
1999-11-01
2001-07-31
Colilla, Daniel J. (Department: 2854)
Printing
Press part or attachment
C101S375000
Reexamination Certificate
active
06267056
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a printing machine with a cylinder sleeve, which can be rotationally driven and is supported at both ends with protruding axle journals directly in the machine frame, and with a shaft, which passes through the cylinder sleeve and can be driven along with it.
A printing machine of this type is disclosed by the EP-A-0 769 373. For this printing machine, the shaft is clamped boom-like in the machine frame, so that, for exchanging printing cylinders, the cylinder sleeve can be pulled off axially from the free end of the shaft, after the bearings for the cylinder sleeve are opened and the unit of shaft and cylinder sleeve has been lifted out of the bearings. The printing cylinder sleeve is driven over a gearwheel, which meshes with a driving gearwheel and is disposed on an extension of the axle journal of the cylinder sleeve.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a printing machine of the type named above, which permits the cylinder sleeve, especially the printing cylinder sleeve, to be exchanged easily and with which the printing cylinder sleeve can be driven directly by means of a driving motor disposed coaxially to it.
Pursuant to the invention, this objective is accomplished owing to the fact that the rotational driving is accomplished over the shaft and the cylinder sleeve can be set axially against a torque transfer element, which is seated on the shaft.
The shaft thus functions not only for supporting the cylinder sleeve during the exchange of cylinders, but also, at the same time, as a driving shaft. Accordingly, it is possible to couple the motor to the driving shaft, without interposing a gear drive. When cylinders are exchanged, the driving connection between the motor and the shaft need not be interrupted. Since the driving torque is transferred from the shaft to the cylinder sleeve simply by axially setting the cylinder sleeve against the torque transfer element, no special measures are required when exchanging cylinders in order to interrupt and restore the driving connection between the shaft and the cylinder sleeve. When the cylinder sleeve is pulled off from the shaft, the driving connection is interrupted automatically and, when the cylinder sleeve once again is pushed axially onto the shaft and reaches its end position on the shaft, it is set once again against the torque transfer element, so that the driving torque can be transferred once more to the cylinder sleeve.
The invention is not limited to the driving mechanism for the printing cylinder sleeve and can be used generally for exchangeable and rotationally driven rotating objects of a printing machine, for example, also for engraved ink transfer rollers and screen rollers of a flexographic printing press and the like.
The direct mounting of the cylinder sleeve in the machine frame has the advantage that the axis of rotation of the cylinder sleeve is defined precisely. Accordingly, it can be achieved that the printing machine runs quietly and the printing quality is perfect. Since, however, pursuant to the invention, the cylinder sleeve is driven over the shaft, which in turn must be supported in the machine frame, it is advisable to configure the support of the shaft and/or of the coupling between the shaft and the cylinder sleeve in such a manner, that redundancies of the axis of rotation are avoided and, accordingly, the axis of rotation of the cylinder sleeve continues to be determined primarily by the mounting of the axle journals in the machine frame. This can be achieved, for example, by mounting the shaft flexibly in the radial direction in the machine frame. If the shaft is coupled rigidly with the rotor of the driving motor, then this means that the rotor of the driving motor or the whole of the driving motor is also held flexibly in the radial direction at the machine frame. This can be achieved, for example, by a construction of the holding mechanism for the motor, which has a certain elasticity in the radial direction of the shaft. The torque transfer element between the shaft and the printing cylinder sleeve can then be constructed, for example, as a cone, which engages a counter-cone at the cylinder sleeve frictionally. When the cylinder sleeve is set axially against the cone, the shaft is centered in this manner on the axis of rotation defined by the axle journal of the cylinder sleeve.
In a different embodiment, the torque transfer element is constructed as a flat friction disk, which interacts with an end face of an axle journal of the cylinder sleeve. A friction coupling, so designed, offers the possibility of compensating for a slight eccentricity in the shaft in relation to the axis of rotation of the cylinder sleeve. In this case, the shaft can therefore also be mounted rigidly in relation to the machine frame.
The two solutions, which are described above and for which the cylinder sleeve is clamped with a relatively high force axially against the torque transfer element, so that a frictional transfer of torque is achieved, at the same time have the advantage that an axially fixed connection is created between the cylinder sleeve and the shaft. By these means, the advantageous possibility opens up of also adjusting the lateral register by way of the shaft. If the shaft is driven directly, it is, however, also necessary to ensure that, in this case, an axial adjustment of the shaft is possible while the driving connection between the shaft and the motor is maintained. This can be achieved, for example, owing to the fact that the rotor of the motor can be adjusted axially relative to the stator. The rotor can then be coupled rigidly with the shaft or constructed in one piece with the latter and participates in the axial movement of the shaft when the lateral register is adjusted. A further possibility consists of providing an axial coupling between the rotor of the motor and the shaft. In this case, during the adjustment of the lateral register, only the shaft is adjusted in the axial direction, whereas the rotor retains its axial position and the relative movement between the shaft and the rotor is compensated for by the axial coupling. Finally, it is also possible to support the whole of the motor housing so that it can be moved axially at the machine frame so that, when the lateral register is adjusted, the cylinder sleeve, the shaft and the motor are moved as a unit.
With respect to a simple and accurate adjustment of the longitudinal register, it is desirable that the cylinder sleeve can be coupled in a defined angular position with the shaft, so that the respective shaft angular position of the cylinder sleeve can be determined automatically with the help of an angular increment pick-up, which is disposed on the shaft or can be attached to the motor or integrated in the motor. For this purpose and, in accordance with a further development of the invention, at least one engaging dog is disposed at the torque transfer element or at the corresponding counter-surface at the cylinder sleeve and falls into a corresponding contour of the respectively other component, when the cylinder sleeve is set axially against the torque transfer element. In the peripheral direction, the engaging dog should engage the counter-contour without clearance, so that the angular position of the cylinder sleeve can be determined precisely. If the torque transfer element is constructed as a flat friction disk, the engaging dog and the counter-contour should, however, be movable in the radial direction relative to one another, so that it remains possible to compensate for the eccentricity between the shaft and the cylinder sleeve. Admittedly, owing to the fact that the engaging dog engages the counter-contour, there is a certain positive locking between the torque transfer element and the cylinder sleeve. However, the cylinder sleeve is clamped so tightly against the torque transfer element, that the torque transfer nevertheless primarily takes place by friction. Therefore, during the operation of the printing machine, the mecha
Kolbe Wilfried
Schirrich Klaus
Steinmeier Bodo
Terstegen Manfred
Colilla Daniel J.
Fischer & Krecke GmbH & Co.
Goldberg Richard M.
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