GB1587026A

GB1587026A - Device for adjustment of the ink metering elements in the inking unit on printing presses

Info

Publication number: GB1587026A
Application number: GB12741/78A
Authority: GB
Original assignee: Roland Offsetmaschinenfabrik Faber and Schleicher AG
Current assignee: Roland Offsetmaschinenfabrik Faber and Schleicher AG
Priority date: 1977-04-01
Filing date: 1978-03-31
Publication date: 1981-03-25
Also published as: DE2714577B2; SE418066B; FR2385531A1; CH628286A5; FR2385531B1; DE2714577A1; DE2714577C3; SE7803679L

Abstract

In addition to the path transmitters for measuring the position of the metering elements and to the adjusting drives for setting the gap between the metering elements and the ductor roller, the device has an apparatus for changing the supply voltage (U) to the path transmitter (3). By changing the supply voltage (U), two signals (U1 and U1') are supplied to a comparison circuit (7), which produces a signal size (S) which adjusts the ink metering elements (2) and is supplied to the adjusting drive (14). If the two signals (U1 and U1') are the same in the comparison circuit (7), the supply voltage (U) to the path transmitter (3) is returned to the initial value again. <IMAGE>

Description

(54) DEVICE FOR ADJUSTMENT OF THE INK METERING ELEMENTS IN THE INKING UNIT ON PRINTING PRESSES (71) We, ROLAND OFFSETMAS CHINENFABRIK FABER & SCHLEICHER AG, a German company of Christian-Pless-Strasse 6-30, 6050 Offenbach am Main, Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a device for adjustment of the ink metering elements in the inking unit on printing presses, in which the position of the ink metering elements can be measured by position sensors and is remotely adjustable by actuators.

The ink control on a printing press depends on several varying parameters, e.g.

temperature in the inking unit, temperature of the printing plate, ink tackiness, damping control etc. The change in these parameters, e.g. during running on, necessitates variation of the ink flow from the fountain roller to the inking unit over the width of the inking unit as a whole.

A device of the type described above is already known, e.g. from German Patent Specification 1,241,840. Potentiometers are provided as position sensors. Common adjustment of the ink metering elements over the full width of the inking unit is possible only in identical steps over the width.

It is also known from German Patent Specification 1,942,732 how to adjust a ductor blade over the full width in relation to the fountain roller and thus meter the ink flow in the direction of the plate.

Furthermore, it is known from German Gebrauchsmuster 7,139,991 how to meter the ink flow from an undershot fountain to the printing plate by varying the contact time of the lifter roller.

All known inking units have a common disadvantage with regard to the overall adjustment. The ductor blade can only be applied or withdrawn by the same amounts over the width of the inking unit. However, this means that the ink film in areas with an already large feed is varied by too high a percentage in comparison with areas with a small feed. In contrast, metering of the ink by varying the contact times of the lifter roller necessitates a considerable amount of design work.

According to the present invention there is provided apparatus for adjustment of the ink metering elements in the inking unit of a printing press, in which the positions of the ink metering elements can be measured by position, sensors and are remotely adjustable by actuators, the apparatus comprising, in addition to a said position sensor and a said actuator for at least one of the elements, (a) an electrical store connected to the position sensor of the element for storage of the actual value assigned to the position of the ink metering element, (b) an interrupter arranged between position sensor and store (c) a comparator circuit in which the output signal of the store can be compared with the output signal of the position sensor and which, in the event of deviation of these signals from each other, controls the actuator attached to the ink metering element, and (d) a device for changing the supply voltage of the position sensor, whereby a signal value resetting the ink metering elements and thus altering the output signal of the position sensor can be fed to the actuator by changing the supply voltage, and, when the output signals of the position sensor and store are identical, the store can be re-connected e.g. via a timing element, and the supply voltage of the position sensor can again be re-set to the initial value.

Such apparatus may be used to affect the ink feed in such a way that the size of the gap determining the ink flow between the fountain roller and ink metering element is varied by a defined preselectable percentage of its value at any given time. Preferably the ink metering elements are designed as slides, which can be moved radially in relation to the ink fountain roller; these permit extremely sensitive control and regulation of the ink flow under the most diverse running on conditions. The apparatus of the present invention may be used to automate the inking during the printing process.

A preferred embodiment of the apparatus of the invention is described in detail below in conjunction with the accompanying drawings, in which: Figure 1 shows schematically an ink fountain roller of a printing press inking unit with adjusted ink metering elements, and Figures 2 and 3 show schematic representations of the ink flow control system.

Referring to the drawings, various ink metering elements 2, 2', 2" 2""' are arranged on the ink fountain roller 1 shown in Figure 1. Each ink metering element 2 can be moved to and fro by an actuator 14 in relation to the ink fountain roller 1. The position of the ink metering elements 2 is detected by a position sensor 3 designed as a potentiometer. The potentiometer output signal U1, which represents the actual value, is determined by the supply voltage U and can be varied by an additional potentiometer 4. It is stored continuously in a store 5.

If a percentage reduction is required for the momentary position of the metering elements, the supply voltage of the potentiometer 3 is increased by adjusting the potentiometer 4. Connection between the potentiometer 3 and store 5 is first prevented by an interrupter 6. Figure 2 shows that two different signals U1 + U1' are now present in the comparator circuit 7 with the result that a signal value S is generated, which operates the actuator 14 and re-sets the ink metering element 2 by a percentage in relation to its initial position. As soon as the voltages U1, U1' in the comparator circuit 7 are again equal, the interrupter 6 is re-closed and the potentiometer 4 re-set to its initial position. This is effected as shown in Figure 3 by operation of switch 8. The output signal at another comparator circuit 9 is connected to an actuator 10 and the potentiometer 4 adjusted until the fixed reference voltage U3 in the comparator circuit 9 and the voltage U4 received from potentiometer 4 are equal. The system is thus ready for a new adjustment.

WHAT WE CLAIM IS: 1. Apparatus for adjustment of the ink metering elements in the inking unit of a printing press, in which the positions of the ink metering elements can be measured by position sensors and are remotely adjustable by actuators, the apparatus comprising, in addition to a said position sensor and a said actuator for at least one of the elements, (a) an electrical store connected to the position sensor of the element for storage of the actual values assigned to the position of the ink metering element.

(b) an interrupter arranged between position sensor and store, (c) a comparator circuit in which the output signal of the store can be compared with the output signal of the position sensor and which, in the event of deviation of these signals from each other, controls the actuator attached to the metering element, and (d) a device for changing the supply voltage of the position sensor, whereby a signal value resetting the ink metering elements and thus altering the output signal of the position sensor can be fed to the actuator by changing the supply voltage, and, when the output signals of the position sensor and store are identical, the store can be re-connected and the supply voltage of the position sensor can again be re-set to the initial value.

2. Apparatus according to claim 1 wherein the store is re-connected via a timing element.

3. Apparatus according to claim 1 wherein the supply voltage of the position sensor is re-set to the output voltage by a comparator and slave circuit and a fixed reference voltage.

4. Apparatus according to any one of the preceding claims wherein the ink metering elements are designed as slides adjustable radially relative to the ink fountain roller.

5. Apparatus for adjusting the ink metering elements in the inking unit of a printing press, substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. gap determining the ink flow between the fountain roller and ink metering element is varied by a defined preselectable percentage of its value at any given time. Preferably the ink metering elements are designed as slides, which can be moved radially in relation to the ink fountain roller; these permit extremely sensitive control and regulation of the ink flow under the most diverse running on conditions. The apparatus of the present invention may be used to automate the inking during the printing process. A preferred embodiment of the apparatus of the invention is described in detail below in conjunction with the accompanying drawings, in which: Figure 1 shows schematically an ink fountain roller of a printing press inking unit with adjusted ink metering elements, and Figures 2 and 3 show schematic representations of the ink flow control system. Referring to the drawings, various ink metering elements 2, 2', 2" 2""' are arranged on the ink fountain roller 1 shown in Figure 1. Each ink metering element 2 can be moved to and fro by an actuator 14 in relation to the ink fountain roller 1. The position of the ink metering elements 2 is detected by a position sensor 3 designed as a potentiometer. The potentiometer output signal U1, which represents the actual value, is determined by the supply voltage U and can be varied by an additional potentiometer 4. It is stored continuously in a store 5. If a percentage reduction is required for the momentary position of the metering elements, the supply voltage of the potentiometer 3 is increased by adjusting the potentiometer 4. Connection between the potentiometer 3 and store 5 is first prevented by an interrupter 6. Figure 2 shows that two different signals U1 + U1' are now present in the comparator circuit 7 with the result that a signal value S is generated, which operates the actuator 14 and re-sets the ink metering element 2 by a percentage in relation to its initial position. As soon as the voltages U1, U1' in the comparator circuit 7 are again equal, the interrupter 6 is re-closed and the potentiometer 4 re-set to its initial position. This is effected as shown in Figure 3 by operation of switch 8. The output signal at another comparator circuit 9 is connected to an actuator 10 and the potentiometer 4 adjusted until the fixed reference voltage U3 in the comparator circuit 9 and the voltage U4 received from potentiometer 4 are equal. The system is thus ready for a new adjustment. WHAT WE CLAIM IS:

1. Apparatus for adjustment of the ink metering elements in the inking unit of a printing press, in which the positions of the ink metering elements can be measured by position sensors and are remotely adjustable by actuators, the apparatus comprising, in addition to a said position sensor and a said actuator for at least one of the elements, (a) an electrical store connected to the position sensor of the element for storage of the actual values assigned to the position of the ink metering element.