GB2385825A

GB2385825A - Printing press with a portable remote console for setting and recording the zero position of at least one ink-key

Info

Publication number: GB2385825A
Application number: GB0204681A
Authority: GB
Inventors: Nicholas Matthew Jones
Original assignee: WOODFORD LITHO Ltd
Current assignee: WOODFORD LITHO Ltd
Priority date: 2002-02-28
Filing date: 2002-02-28
Publication date: 2003-09-03
Also published as: GB0204681D0

Abstract

A method for setting and recording the zero or datum position of at least one ink-key 11 of a printing press comprises: a) locating a portable remote console 22 at a position whereat an operator can see an ink-key 11 to be adjusted and also operate the console 22, which console is in communication with the control electronics 16 of the press (e.g. via wireless communication with base unit 20) to permit adjustment of the ink-key 11 and an associated duct blade 7 by inputs fed into the console 22; b) using the portable console 22 to adjust the position of the ink-key 11 whilst viewing the ink-key until a desired datum position is reached; and c) using the portable console 22 to instruct the control electronics 16 to record the datum position. A printing press incorporating a portable remote console, and a portable remote console for use in the method are also disclosed. Feedback from a potentiometer 14 may be used to indicate the position of the ink-key.

Description

Ink-Key Control The present invention relates to a method for setting the zero or datum position for ink-keys on an electronically controlled web-offset litho printing press. It also relates to equipment for use in such a method and to a printing press adapted for use with such a method.

In web-offset litho printing presses the means for imparting ink onto paper includes ink ducts, which are filled with ink of the required colour. These ducts are next to duct rollers that are used to carry the ink onto other rollers for subsequent transfer onto the paper. The amount of ink transferred from the duct to the roller is controlled by an adjustable duct blade, which is moved by a servomotor system. On many systems the servomotor system drives a finger-like rod (called an ink-key) which bears upon the duct blade to vary the ink flow onto the roller. Many servomotor systems include a feedback potentiometer which can supply details of the key's position to a system controller.

When changing any of these components, commissioning a new press, or resetting an old press, the position of each ink-key must be carefully adjusted to a zero (or datum) position. At this position the duct blade imparts just enough force on the roller to allow essentially no ink transfer to the roller. Too little force and ink will get on to the roller when not desired (causing poor print quality) but too great a force and damage to the duct blade and the roller can occur.

The existing zeroing method requires a skilled technician to adjust the position of each key and then to set the zero position in the printing press's control system. Such manual adjustment requires the skilled technician to

disengage (usually using a clutch mechanism) the servomotor from the inkkey. The servomotor is then re-engaged with the ink-key once the key has been manually adjusted. The technician then must return to the press's control panel and operate the"zeroing"switch. This switch causes the control electronics to read back the feedback voltages (supplied by the potentiometers) from the ink-keys and store these as datum positions. To ensure normal operation, these readings will only be accepted if they are within set limits, and any keys that do not return a suitable feedback voltage must be readjusted, and the whole process repeated, until the combination of an acceptable feedback voltage and actual zero ink transfer is achieved. This process is both highly skilled and time consuming as the technician might need to move backward and forwards between the keys and the press's control console to keep testing the manually set key positions.

A single roller might have 26 keys along its length and a press might have several rollers for each side of the paper. Therefore a single press might have many keys, for example 104 or more, to be adjusted. In consequence the setting of the datum position for the ink-keys is a very slow process and contributes to long periods of down time.

It is an aim of the present invention to provide a method of setting the zero or datum position of ink-keys on web-offset litho printing presses, which method is faster and easier to perform than existing techniques. It is a particular preferred aim to provide a method and apparatus that allows implementation of the method on existing presses.

Therefore according to the present invention there is provided, in an electronically-controlled web-offset litho printing press, a method of setting the

initial datum position of at least one of a plurality of ink-keys each having an associated duct blade, which method comprises: a) locating a portable remote console at a position whereat an operator can see an ink-key to be adjusted and also operate the remote console, which remote console is in communication with the press's control electronics to permit the position of the ink- key and consequently also the position of the associated duct blade relative to a roller against which the duct blade bears to be adjusted by means of inputs fed into the remote console; b) using the remote console to adjust the position of that ink-key while viewing the ink-key and duct blade, until a desired datum position is reached; and c) using the remote console to instruct the press's control electronics to record the datum position for that ink-key.

It is preferred that after step c) the method further comprises: d) repeating steps b), and c) for each ink-key and duct blade for which an initial datum position is to be set.

The ink-keys generally contain a feedback potentiometer, which will supply voltage readings and indicate the position of the ink-key to the control system. These voltages should be within certain boundaries to ensure the system is operating within the correct parameters. It therefore is also preferred that the recording of the datum position during step c) includes : taking a reading from a feedback potentiometer connected to the ink-key; comparing the reading to a preset range; and then, if the reading falls within the range, recording the datum. If the reading does not fall in the preset

range, the user is informed so that step b) onwards can be repeated until the reading is in the preset range.

The remote console must be portable so that the operator may position it such that it can be used whilst the ink-keys are visible. In effect the operator would take the control console to a place adjacent the ink-keys and from there would undertake the remaining steps of the method-unless of course the operator needed to move to see the other ink-keys, in which situation the control console would be repositioned accordingly.

The remote console must remain in communication with the printer's control electronics, and this can be done by any appropriate means. It is preferred that such communication uses wireless technology, such as radio or infra-red signals, because this allows complete freedom of movement.

Alternatively a control console using a trailing umbilical cable, plugged into the press's control system would be equally appropriate. It is also desired that the remote console be provided with a power source, such as a battery or power lead (which could form part of the umbilical cable).

It is possible to adjust the position of each ink-key prior to simultaneously zeroing all of the keys. Alternatively, it is also possible to set the datum position after the adjustment of each individual ink-key.

An overall duct blade running the length of a duct roller can be formed from a sectional steel blade, or from a plurality of individual duct blades. Each section or individual duct blade can be adjusted by one or more ink-key. In certain circumstances it is preferred that at least two ink-keys control a section of duct blade and each of the ink-keys is simultaneously adjusted before setting the datum position for both.

The portable control console for use with this method is clearly an important feature of this invention. Therefore according to this invention there is also provided a portable control console, for use in the above method, which comprises an operator interface through which an operator may operate the console, and means for communication with the printer's control electronics.

Such a control console must provide an interface through which an operator may input control information. Preferably, the operator interface is a touch screen panel, but it may instead or in addition include conventional control switches and buttons. As mentioned above this console may communicate using any suitable remote communication means such as trailing wires or wireless transmission.

The present invention is particularly well adapted for use on existing presses, to simplify their use. In such retro-fittings the console may be adapted to connect to the existing control mechanisms after suitable adaptation thereof. To facilitate this, the console might also include a nonportable base unit which connects to the press's controller, which base unit is adapted to communicate with the portable control console and act as an interface between the console and the press's control electronics.

According to the present invention there is further provided an electrically controlled, web-offset litho printing press which includes an operator portable control console in communication with the press's control electronics and adapted to receive inputs to permit adjustment of the ink-keys and subsequent datum recording therefor.

In order that it may be better understood, but by way of example only, the present invention will now described with reference to the accompanying

drawing, Figure 1 which is a stylised view of the control console in use for adjusting an ink-key.

A sprung steel duct blade 5 bears on a duct roller 6 and defines therebetween an ink duct 7 in which a reservoir of ink is held. A moveable rod 10, of an ink-key unit 11, controls the degree to which the duct blade 5 bears on the roller 6, thus in turn controls the amount of ink which the roller 6 will pickup as it rotates (in the direction of arrow A). By moving the duct blade 5 toward the roller 6, the amount of ink flow (or ink film thickness) on the roller will decrease until essentially no ink is transferred. This "zero" ink value is needed as a datum position for control of the ink-keys during normal printing. Conversely movement of the duct blade 5 away from the roller 6 will allow greater ink flow onto the roller.

If the duct blade 5 bears too forcefully on the roller 6, due to over extension of the rod 10, the duct blade 5 can cause damage to the roller 6, which will in turn shorten the operational life of the roller and blade, and will decrease print quality. However, if the blade is not close enough in its recorded datum position, ink will seep onto the roller and will either be wasted or will ruin print quality. Therefore the setting of this zero or datum position is important and requires a high degree of skill.

In a press there could be many separate duct blades along one roller, or instead a long sectional duct blade might be used. There would also be several rollers. Therefore many keys would need setting, but for convenience only one is shown in Figure 1. The ink-key unit 11 includes an electric motor 12, which is connected by a suitable reduction gearbox 13 and screw thread 15 to the rod 10, such that operation of the motor 12 will extend or retract the rod 10. A feedback potentiometer 14 is connected to the gearbox 13 to

provide an output dependent upon the position of the rod 10. The potentiometer 14 and the motor 12 are connected by wires 17,18 to a system controller 16 that governs the operation of the press.

A base unit 20 is connected to the system controller 16 and is in communication therewith. The base unit 20 might actually be a part of an integrated newly constructed system controller, but in this embodiment it is a retro fitted module adapted to connect the system controller 16 and operate as an interface between the existing system controller and a portable control console 22.

The control console 22 is an operator portable tablet with a touch screen interface 24. It is in wireless communication with the system controller 16 through the interface provided by the base unit 20, each of which contain appropriate transmitting/receiving equipment. In operational mode, the touch screen has various "button" areas that can be used by an operator to control certain functions, and it also has other areas that display information to the operator. In this embodiment the touch screen is provided with the following : a key extender button 25, operation of which moves the rod 10 toward the duct blade 5; a key retractor button 26, which moves the rod 10 away from the duct blade 5; a zero button 27, which causes the recording of the datum position for a specified key; a zero all button 28, which causes the datum for all keys to be simultaneously recorded; a key select button 29, which allows the selection of the ink-key 11 which is to be adjusted; and an information display 30 which provides information from the potentiometer 14. On operation of these buttons the control console 22 communicates with the system controller 16, which takes appropriate actions. For example on activation of the key extender button 25 the system controller 16 operates the

motor 12 in a direction which causes the rod 11 to be extended toward the duct blade 5. Conversely the key retractor button 26 causes the motor 12 to operate in the reverse direction.

In use, when performing the method of the present invention, an operator would move the control console 22 to a location adjacent an ink-key 11 to be adjusted, such that the operator can see the ink-key 11 and the duct blade 5 relative to the roller 6, whilst still being able to access the touch screen. The operator would then use the key retractor button 26 and the key extender button 25 to move the ink-key 11 and consequently the duct blade 5 to a desired position relative to the roller 6, such that on rotation of the roller 6 no ink is transferred to the roller 6, but without inappropriate wear on the roller.

Then, by operating the zero button 27, the value provided by the potentiometer 14 is stored in the system controller 16 thus recording the datum position for that ink-key. When zeroing of the ink-key is needed in normal operation of the press (i. e. when none of the particular ink is required), the motor 12 can adjust the rod 10 until the potentiometer 14 provides a reading that matches the datum value.

When the position of one ink-key is correctly set the key select button 29 can be used to select the next ink-key that requires positioning.

If necessary the operator can then move the control console 22 to a new position to ensure that a view of the ink-key is maintained. The touch screen display 24 also provides information concerning the process and parameters. For example the display 30 in this embodiment provides information from the potentiometer 14. Often to operate in normal use, the potentiometer reading at datum must be within a certain range, and if it is not then the datum will be rejected during recording. Therefore, the supply of the

reading to the operator can assist in ensuring that when the zero button 27 (or the zero all button 28) is pressed the potentiometer is in the correct range, and the datum will therefore not be rejected by the system controller 16. The datum position for each ink-key 11 can be recorded after positioning of each individual ink-key. Alternatively each ink-key can be adjusted before simultaneous datum recording for all is performed using the Zero all button 28.

Claims

Claims 1. In an electronically-controlled web-offset litho printing press, a method of setting the initial datum position of at least one of a plurality of ink-keys each having an associated duct blade, which method comprises: a) locating a portable remote console at a position whereat an operator can see an ink-key to be adjusted and also operate the remote console, which remote console is in communication with the press's control electronics to permit the position of the ink- key and consequently also the position of the associated duct blade relative to a roller against which the duct blade bears to be adjusted by means of inputs fed into the remote console; b) using the remote console to adjust the position of that ink-key while viewing the ink-key and duct blade, until a desired datum position is reached; and c) using the remote console to instruct the press's control electronics to record the datum position for that ink-key.
2. A method as claimed in claim 1, which after step c) the method further comprises: d) repeating steps b), and c) for each ink-key and duct blade for which an initial datum position is to be set.
3. A method as claimed in claim 1 or claim 2, in which the recording of the datum position during step c) includes : taking a reading from a feedback potentiometer connected to the ink-key; comparing the reading to a preset range; and if the reading falls within the preset range, recording the datum

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position, but if the reading fails to fall in the preset range, causing step b) onwards to be repeated, until the reading is in the preset range.
4. A method as claimed in any of the preceding claims, in which the remote console communicates with the control electronics using wireless communication.
5. A method as claimed in any of claim 1 to claim 3, in which the remote console communicates with the control electronics using a trailing cable.
6. A method as claimed in any of the preceding claims, wherein a nonportable base unit is used, which base unit is integrated with the press's control electronics and which acts as an interface between the portable remote console and the control electronics.
7. A method as claimed in any of the preceding claims, wherein the position of every ink-key is adjusted before the datum position for all is recorded.
8. A method as claimed in any of claim 1 to claim 6, wherein the datum position is recorded after positioning of each individual ink-key.
9. A method as claimed in any of the preceding claims, in which at least two ink-keys control a duct blade, or a section of duct blade, and each ink-key is simultaneously adjusted before setting the datum position for both.
10. A control console for use in a method according to any of the preceding claims, which console is portable by an operator and which comprises an operator interface through which the operator may input instructions concerning the positioning of the ink-keys and the recording of the datum position, and means for communication with the press's control electronics.

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11. A control console as claimed in claim 10, in which the operator interface is a touch screen that is also adapted to display to the operator information that is supplied from the control electronics.
12. A control console as claimed in claim 10 or claim 11, in which the means for communication include a wireless transceiver.
13. A control console as claimed in claim 10 or claim 11, in which the means for communication include a trailing wire connected to the control electronics.
14. A control console as claimed in any of claim 10 to claim 13, which is provided with a non-portable base unit which is adapted for connection to the press's control electronics and which acts as an interface between the portable console and the press.
15. An electronically controlled web-offset litho printing press including at least one ink-key having an associated duct blade, which press includes a portable control console that is in communication with the press's control electronics and which is adapted to permit adjustment of the ink-keys, and subsequent recording of a datum position.
16. A web-offset litho printing press as claimed in claim 15, which further includes a non-portable base unit which is adapted for connection to or integration with the press's control electronics and which is adapted to form an interface between the portable control console and the control electronics.