GB2073671A

GB2073671A - Inking control system for a printing machine

Info

Publication number: GB2073671A
Application number: GB8111170A
Authority: GB
Original assignee: Polygraph Leipzig Kombinat Veb
Current assignee: Polygraph Leipzig Kombinat Veb
Priority date: 1980-04-10
Filing date: 1981-04-09
Publication date: 1981-10-21
Also published as: JPS56157365A; IT8167479A0; SE8102282L; FR2480186A1; IT1143532B

Abstract

An inking device remote resetting system for a multicolour printing machine comprises an ink box (1) supporting motorised setting elements (6) which are associated with a continuous ductor blade (2) of the ink box and which are controlled from a remote operating control desk (7). The ink box (1) and a ductor roller (3) co-operating with the ink box are constructed to be resistant to bending. The ductor blade (2) is acted on by support elements (5) which are protected against contamination, are connected with the setting elements (6), and are arranged near the cutting edge of the ductor blade (2). The setting elements (6) associated with each ink zone are constructed as single step motors controlled by a control network (4) into electrically equivalent positions before and after the execution of a setting step. The resetting system further comprises setting measurement transmitters (12) detecting the settings of the single step motors, and a computer (10), which is associated with the control-network (4) and which initiates adaptation of the irregular course of the positions of the support elements to the steady function of the ductor blade bending line on predetermined limit values being exceeded for the discontinuity of the positions of neighbouring setting elements adjoining at both sides. <IMAGE>

Description

SPECIFICATION Inking control system for a printing machine The present invention relates to an inking control system for a printing machine, and. has particular reference to an inking device remote resetting system for a multicolour printing machine.

Inking device remote resetting systems for multicolour web printing machines are known, such systems consisting of an ink box with a ductor roller and a ductor blade and remotely operable blade support elements acting on the blade. However, a differentiated ink flow meeting the high quality requirements in sheet printing cannot be achieved by this system.

There are also known inking device remote resetting systems for multi-colour sheet printing machines (DE 2714577) which dispense with an undivided ductor blade and are associated with ink slides and similar elements forming the ductor blade. It is disadvantageous that these elements are exposed to contamination, so that a precise, consistently reproduceable setting of the ink flow is not possible with these systems, as a consequence of gluing or wedging together. The difficulties in obtaining a satisfactory setting are also due to the use of generally unsuitable resetting means and method of driving same. The setting time is relatively long and cost of the entire equipment is high.

.There is accordingly a need for an inking control system which utilises a conventional. continuous ductor blade and which provides a high degree of operating reliability while coping with extreme ink profiles and ensuring a precise, consistently reproduceable control of ink flow.

According to the present invention there is provided an inking control system for a printing machine comprising a rigidly constructed ink box provided with a continuous ductor blade, a ridigly constructed ductor roller co-operable with the blade, a row of adjustahle support elements acting on the blade in the region of an operative edge thereof, a respective setting drive operatively coupled to each support element and operable to adjust the position thereof, detecting means for detecting the settings of the drives and providing setting signals indicative of the detected settings, control means for controlling the operation of the drives, the drives being so controlled as to return to electrically equivalent rest settings after adjustment operations, and determining means associated with the control means and so responsive to setting signals indicating a difference between the settings of adjoining support element drives above a threshold value as to determine control magnitudes for controlling the drives to adjust the positions of the support elements so that the course of such positions along the row conforms to the line of flexion of the blade.

In a control system embodying the invention, the ink box and ductor roller are expediently constructed to be resistant to bending. The blade support elements are preferably protected against contamination by dirt, are connected with the setting drives, and are arranged near the cutting edge of the ductor blade. The setting drives associated with each ink zone may be constructed as single step motors controlled by the control network into electrically equal positions before and after the execution of an adjusting step, according to the principle of control.The determining means preferably comprises a computer which initiates the adaptation of the irregular course of the positions of the support elements to the steady function of the ductor blade bending flexion line on predetermined limit values being exceeded for the discontinuity of the positions of neighbouring setting drives adjoining at both sides.

An embodiment of the present invention will now be more particularly described by way of example and with reference to the accompanying drawing, which is a schematic, partly sectioned view of an inking device remote resetting system according to the said embodiment.

Referring now to the drawing, there is shown an inking device remote resetting system which comprises an ink well 1 with a continuous ductor blade 2 and a ductor roller 3. The ink well 1 and the ductor roller 3 are constructed to be extremely rigid and resistant to bending, so that no falsification of setting values can arise due to bending and torsion. Ductor blade support elements act on the ductor blade 2 near the cutting edge thereof. The support elements expediently consist of adjustable pivotal levers 5, on which the setting elements 6 act by way of ink zone threaded pins 1 The elements 6 are arranged underneath the ductor blade 2 or at places not susceptible to contamination and are protected against dirt by additional measures, such as drip pans or films. Gluing or wedging together of the support elements thus cannot occur.

The setting elements 6 are constructed as stepping motors drivingly coupled by gear means to the pins 1 the stepping motors being disposed, for simplification of the control measures, in an electrically equal position before and after the execution of adjusting steps. The control of the stepping motors takes place by way of a control network 4. The stepping motors include setting measurement transmitters 12, which are constructed as potentionmeters and which deliver signals having magnitudes indicative of the settings of the stepping motors.

The use of stepping motors in conjunction with the described manner of driving ensures a consistently reproduceable setting of the support elements and precise indication of the settings of the motors. The control network 4 is controlled by a remote control desk 7, which includes operating elements 8 and indicating elements 9 for each ink zone pin.

Associated with the control network 4 is a computer 10, which undertakes the adaptation of the irregular course of the positions of the support elements to the constant function of the ductor blade bending line when predetermined limit values are exceeded for the discontinuity of the positions of neighbouring setting elements adjoining at both sides.

It is thus possible, without knowledge of the function of the blade bending line, to avoid a situation where the ductor blade 2 does not follow the setting elements on resetting.

The resetting system hereinbefore described allows use of an undivided ductor blade for quality printing and thus creates an effective and economically producible system satisfying the stated requirements.

Claims

1. An inking control system for a printing machine comprising a rigidly constructed ink box provided with a continuous ductor blade, a rigidly constructed ductor roller co-operable with the blade, a row of adjustable support elements acting on the blade in the region of an operative edge thereof, a respective setting drive operatively coupled to each support element and operable to adjust the position thereof, detecting means for detecting the settings of the drives and providing setting signals indicative ofthe detected settings, control means for controlling the operation of the drives, the drives being so controlled as to return to electrically equivalent rest settings after adjustment operations, and determining means associated with the control means and so responsive to setting signals indicating a difference between the settings of adjoining support element drives above a threshold value as to determine control magnitudes for controlling the drives to adjust the positions of the support elements so that the course of such positions along the row conforms to the line of flexion of the blade.

2. A system as claimed in claim 1, comprising means protecting each support element against contamination by foreign matter.

3. A system- as claimed in either claim 1 or claim 2, further comprising a remote control unit for controlling the control means and determining means.

4. A system as claimed in any one of the preceding claims, wherein each of the drives is operatively coupled to the respective support element by way of a threaded adjusting pin, the pin being rotatable by the drive.

5. A system as claimed in any one of the preceding claims, wherein each of the support- elements comprises a pivotable lever bearing against the blade.

6. An inking control system for a printing machine, the system being substantially described with reference to the accompanying drawing.