Printing – Inkers – Roller
Reexamination Certificate
1999-10-18
2001-11-06
Yan, Ren (Department: 2854)
Printing
Inkers
Roller
C101S351300, C101SDIG029
Reexamination Certificate
active
06311617
ABSTRACT:
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The invention concerns a printing press with a vibrator-like or ductor-like inking unit that includes a vibrator or ductor roller that is movable by a motor via a rotatable cam disc, and a method for operating such a printing press.
The published German Patent Document DE 44 36 102 A1 describes a device and a method for controlled transfer of printing ink. The device includes an ink vibrator or ductor roller reciprocatingly movable by a swivel mechanism having an intermittent drive. In one embodiment of the device, a rotatable motor is provided that is connected to a cam-disc segment having two different radii, however, no information is presented about the type of construction of the motor.
In the published German Patent Document DE 44 28 403 C2, a ductor or vibrator drive is described having a cam disc to which a speed-controllable, irregularly drivable drive is assigned. Also provided is a roller of a supporting lever of the ductor or vibrator roller, the supporting-lever roller running along the cam disc. The cam disc occasionally runs at a speed correlating with the printing speed of the printing press and, when the supporting-lever roller runs along the section of the cam disc that causes the ductor roller to be thrown on and thrown off, the cam disc runs at a constant speed independently of the printing speed.
The last-mentioned patent document does not address either the problems associated with the roller lifting from the cam disc due to centrifugal force, or a reduction in the speed of the cam disc.
In the published European Patent Document EP 0 623 468 B1, a ductor or vibrator inking unit for a printing press is described which includes two cam discs having a large radius of curvature for most of the peripheral contour thereof, and a small radius of curvature in the remaining part of the peripheral contour thereof.
Both the device for the controlled transfer of printing ink and also the ductor inking unit, respectively, represent a favorable structural concept for the basic task of the inking unit and the device, respectively. For other cases, however, these systems are unfavorable. In particular, a cam roller following the described cams can lift from the cam at high machine speeds, the position of the ductor roller being occasionally undefined.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a printing press with a ductor or vibrator inking unit that operates reliably at high machine speeds. A further object of the invention is to provide a method for operating such a printing press.
With the foregoing and other objects in view, there is provided, in accordance with one aspect of the invention, a printing press with a ductor inking unit having a ductor roller and comprising a motor for moving the ductor roller via a rotatable cam disc, the motor being constructed so as to subject the cam disc to periodic angular acceleration at constant printing speed of the printing press, and so as to rotate the cam disc alternatingly in opposite rotational directions.
In accordance with another feature of the invention, the cam disc has two peripheral sections contoured as circular arcs and defined by different radii of curvature.
In accordance with a further feature of the invention, the cam disc is peripherally contoured in an approximately spiral shape.
In accordance with another aspect of the invention, there is provided a printing press with a ductor inking unit having a ductor roller and comprising a motor for moving the ductor roller via a rotatable cam disc having two peripheral sections contoured as circular arcs and defined by different radii of curvature and via a cam roller rolling on the cam disc, the motor being constructed so as to drive the cam disc with periodic angular acceleration at constant printing speed of the printing press, the cam disc being rotatable at a reduced speed by the motor when the cam roller traverses a peripheral section of the cam disc having a curvature tending to cause the cam roller to be lifted from the cam disc.
In accordance with an added feature of the invention, the motor is constructed so as to drive the cam disc in a single direction of rotation.
In accordance with an additional feature of the invention, the motor is constructed so as to turn the cam disc alternatingly in opposite directions of rotation.
In accordance with yet another feature of the invention, the motor is an electric motor controllable by an electronic control in dependence upon a printing-press drive for determining the printing speed, and for rotating the motor with periodic angular acceleration.
In accordance with yet a further feature of the invention, the motor has a shaft, and the cam disc is disposed on the shaft in a position coaxial therewith, the cam disc being fixed to the motor shaft against rotation relative thereto.
In accordance with an additional aspect of the invention, there is provided a method for operating a printing press with a ductor inking unit having a ductor roller movable by a motor via a rotatable cam disc, which includes turning the cam disc by the motor alternatingly in opposite directions of rotation and subjecting the cam disc to periodic angular acceleration while the printing speed of the printing press is held constant.
In accordance with a concomitant aspect of the invention, there is provided a method for operating a printing press with a ductor inking unit having a ductor roller movable by a motor via a rotatable cam disc having two peripheral sections contoured as circular arcs defined by two different radii of curvature, which comprises driving the cam disc by the motor with periodic angular acceleration while the printing speed of the printing press is held constant, and controlling the motor by an electronic control so that a spring-loaded roller of a cam drive rolling on the cam disc is held securely in contact with the cam disc at all times, by having the cam disc rotated at a reduced speed by the motor while the cam-drive roller runs over a peripheral section of the cam disc that, due to the curvature thereof, tends to lift the cam-drive roller from the cam disc.
A printing press according to the invention has a ductor inking unit that includes a ductor roller movable by a motor through the intermediary of a rotatable cam disc, the motor being constructed so as to subject the cam disc to periodic angular acceleration at constant printing speed of the printing press and so as to rotate alternatingly in opposite rotary directions.
In a further embodiment beneficial for the printing press, the cam disc has two peripheral sections contoured as circular arcs and defined by different radii of curvature.
In a further embodiment, the cam disc is peripherally contoured to have a spiral or substantially spiral shape.
A further embodiment of the printing press according to the invention has a ductor inking unit that includes a ductor roller movable by a motor via a rotatable cam disc, the cam disc having two peripheral sections contoured as circular arcs and defined by different radii of curvature, and the motor being constructed to drive the cam disc so that it is subjected to periodic angular acceleration at constant printing speed of the printing press, the cam disc being rotated by the motor with reduced speed while the roller rolls on the cam disc over a peripheral section thereof having a curvature tending to lift the roller from the cam disc.
A further embodiment involves an advantageous development of the printing press according to the invention in that the motor is constructed to drive the cam disc rotatingly in a single direction, in particular, intermittently.
A further embodiment calls for the motor to be constructed so as to rotate the cam disc alternatingly in opposite rotary directions.
A further embodiment involving a development of the printing press according to the invention calls for the motor to be an electric motor controllable by an electronic control system in a manner dependent upon a printing press drive determining t
Herden Matthias
Wagensommer Bernhard
Greenberg Laurence A.
Heidelberger Druckmaschinen AG
Lerner Herbert L.
Stemer Werner H.
Yan Ren
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