Printing – Inkers – Roller
Reexamination Certificate
1998-12-17
2003-06-17
Eickholt, Eugene H. (Department: 2854)
Printing
Inkers
Roller
Reexamination Certificate
active
06578481
ABSTRACT:
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a method and device for operating a rotary printing press which includes an inking unit having at least one ink distributor roller that oscillates axially with a variable stroke amplitude.
With regard to the method of the invention, it is noted that operating methods have become known heretofore that provide for continued operation of the printing unit without transporting printing material and of the inking unit without feeding and removing ink, whenever interruptions in operation should occur. Lateral distribution is reduced so that in this operating state the ink layer thickness profile, which varies zone by zone in the inking unit, is preserved. Before resumption of the printing mode, predampening of the inking unit is performed. The predampening is necessary so that the ink/dampening medium balance in the inking unit and on the printing form, which was interfered with by dampening-medium evaporation during the interruption, is adjusted immediately to a value favorable for the production run, thereby preventing the development of spoiled copies or waste.
The published European Patent Document EP 0 545 237 B1 describes an inking unit wherein a resumption of a traversing motion of distributor rollers is performed simultaneously with the positioning of ink applicator rollers against a printing form. This can be effected by linking the “printing on” command by circuitry to a tripper device that actuates a switch coupling of the distributor roller, and by linking the tripper device to a pneumatic cylinder that sets the ink applicator rollers into and out of position, respectively. With an inking unit that can be operated in this manner, the ink profile crosswise to the printing direction is able to be maintained considerably longer during the interruption than if there were continued distribution, yet no favorable inking of the printing form is able to be achieved.
The published European Patent Document EP 0 705 692 A1 describes a method and a device for repositioning an inking unit, but they do not overcome the aforementioned inadequacies of the prior art.
With regard to the device according to the invention, it has become known heretofore to use devices for varying lateral-distribution stroke, with which the stroke of a rotating distributor roller can be increased and decreased with the inking unit operating.
In the published German Patent Document DE 36 29 825 A1, a device for axially adjusting the distributor rollers is described, with which the axial motion of the distributor rollers can be regulated from zero to a maximum, and which includes a regulating segment with a drive groove. The regulating segment is rotatably supported on a shaft in a side wall. A device constructed in this manner is technically less complicated to produce, in comparison with the device described in the aforementioned European Patent Document EP 0 545 237 B1, and is less vulnerable to malfunction, because no correctly in-phase latching of coupling parts need be taken into consideration structurally, yet it takes up a great amount of space. Furthermore, an abrupt change between a minimal stroke and a maximal stroke is not possible, because the rotation and locking of the regulating segment with the aid of the gear wheels still takes a relatively long time.
In the German Patent Document DE 25 07 179 C2, a drive for traversing distributor rollers is described that does not overcome the inadequacies of this last-described reference in the prior art.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a method and device for driving a rotary printing press by which the number of spoiled copies resulting from brief interruptions in the operation of the rotary printing press is minimized.
With the foregoing and other objects in view, there is provided, in accordance with one aspect of the invention, a method for operating a rotary printing press including an inking unit having at least one ink distributor roller that oscillates axially with a variable stroke amplitude, which comprises operating the rotary printing press in a “printing interruption” operating mode, wherein the ink distributor roller oscillates with minimal stroke, and subsequently operating the rotary printing press in a “printing operation” operating mode, wherein the ink distributor roller oscillates with a normal stroke, and before beginning to operate the rotary printing press in the “printing operation” operating mode, increasing the stroke amplitude of the ink distributor roller.
In accordance with another mode, the method of the invention includes increasing the stroke amplitude from the minimal stroke to the normal stroke.
In accordance with a further mode of the method of the invention, the inking unit has at least one ink applicator roller engageable with and disengageable from a printing form, and the method includes increasing the stroke amplitude when the ink applicator roller is disengaged from the printing form.
In accordance with an added mode of the method of the invention, the inking unit has a plurality of the ink applicator rollers, and the method includes increasing the stroke magnitude when all of the plurality of ink applicator rollers are disengaged from the printing form.
In accordance with an additional mode of the method of the invention, the rotary printing press is a planographic press, and the method includes, before beginning to operate the rotary printing press in the “printing operation” operating mode, predampening the printing unit while thus increasing the stroke amplitude of the ink distributor roller.
In accordance with yet another mode, the method of the invention includes increasing the stroke amplitude to the normal stroke.
In accordance with yet a further mode of the method of the invention, the press is an offset printing press.
In accordance with yet an added mode, the method of the invention includes activating a feeding of dampening medium into the inking unit for the predampening simultaneously with increasing the stroke amplitude of the ink distributor roller.
In accordance with yet an additional mode, the method of the invention includes activating a feeding of dampening medium into the inking unit for the predampening after increasing the stroke amplitude of the ink distributor roller.
In accordance with still another mode of the method of the invention, the planographic press has a dampening unit, and the method includes feeding dampening medium from the dampening unit to the inking unit via at least one roller connecting the inking unit to the dampening unit.
In accordance with still a further mode of the method of the invention, the dampening unit includes at least one dampening medium applicator roller engageable with and disengageable from the printing form, and the method includes predampening the inking unit when the dampening medium applicator roller is disengaged from the printing form.
In accordance with still an added mode of the method of the invention, the minimal stroke is at standstill and has a magnitude of zero.
In accordance with still an additional mode, the method of the invention includes varying the stroke amplitude of the ink distributing roller by triggering a device.
In accordance with another mode, the method of the invention includes triggering the device by an electronic control unit.
In accordance with a further mode of the method of the invention, the device that is triggered for varying the stroke amplitude is an adjustable entrainer having a coulisse and a sliding block.
In accordance with another aspect of the invention, there is provided a device for varying the stroke amplitude of at least one axially oscillating distributor roller in an application unit of a rotary printing press, wherein a distributor roller is drivable by a distributor stroke drive via a distributor stroke transmission including a coulisse having a groove and being adjustable from a first position to a second position, and a sliding block movable in the groove, comprising a first
Beisel Hermann
Junghans Rudi
Eickholt Eugene H.
Heidelberger Druckmaschinen AG
LandOfFree
Method and device for operating a rotary printing press does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and device for operating a rotary printing press, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and device for operating a rotary printing press will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3132214