摘要:
A feeder for a sheet-fed printing machine having a feeder table having at least one pulling unit coupled to the machine drive train for imparting to each newly arrived sheet a defined direction of pull, and a sensing arrangement for sensing the position of the side edges of the sheet, the feeder which includes at least one sensor having a response range, facing a respective side edge of the sheet, the sensor which produces two distinctly different signals that indicate the presence or absence, respectively, of the sheet in the desired position of the sheet before and after imparting the pull; electronic logic control apparatus operatively responsive to the signals from the sensor that are produced at the first and second interrogation of the sensor before and after the pull for determining if the sheet after the pull is positioned within the response range of the sensor; and alarm indicator operatively responsive to the logic control apparatus for producing an alarm indication in case it is determined by the logic control apparatus, that the respective sheet edge is not present within the response range of the sensor after the second interrogation.
摘要:
Checking device for protecting against faults arising from a paper wind-up in a rotary printing machine having a printing unit with a blanket cylinder and a printing-unit protecting grid, the checking device including at least one control device disposed in stationary relationship with respect to and adjacent the blanket cylinder and upstream in travel direction of paper through the printing machine, of a location at which the paper wind-up is produced and including a photoelectric sensor formed as a contrast measurement detector for scanning the blanket of the blanket cylinder and generating a signal when a print product is present, the sensor being mounted on the protecting grid at a lower region thereof and being foldable away together with the protecting grid.
摘要:
Device for monitoring imbricated sheets stream fed to a printing machine, including a scanning roller rotatably mounted on a carrier above a base of imbricatedly arranged sheets, the carrier being adjustable by a servomotor so that the scanning roller rotates only when a given number of sheets are arranged on top of one another, a sensor cooperatively associated with the scanning roller, and an intermediate roller movable transversely with respect to its axis and substantially perpendicularly to the plane of the sheets, the intermediate roller being disposed between the scanning roller and the base, comprising a device for measuring the distance of at least one of the scanning roller and the intermediate roller to the base of the overlapped sheets, a control unit coupled with the sensor, the servomotor and the measuring device and a device for producing a signal characteristic of an angle of rotation of the printing machine, the signal being fed to the control unit, the control unit having a device for monitoring the imbricated sheet structure, the scanning roller being mounted so that its rotation is unlimited, and the sensor having a device for detecting all rotational movements of the scanning roller.
摘要:
A device for monitoring sheet transport at sheet feeders for printing machines includes at least one photo-sensor disposed above at each side, respectively, of the sheet feeder, apparatus for providing adjustable positioning of said photo-sensors in spaced relation to the leading edge and corners of the sheet; control logic responsively connected to the photo sensors for processing signals from the photo-sensor for producing a fault indication in case a sheet feeding failure is detected by the photo-sensors.
摘要:
Electrical safety device for controlling a printing machine having a control transformer with a plurality of primary and secondary taps for varying voltage levels including respective control lines connected to the secondary taps, a voltage monitoring device connected in a respective control line of one of the secondary taps, and a voltage changing switching device operatively associated with one of the primary taps, the voltage monitoring device being coupled with the voltage changing switching device.
摘要:
An encoder device for the determination of absolute angle or linear segments is described, with which the distance from the actual to the reference position is determined upon prompting and output via incremental signals. This encoder offers new functions for the incremental measuring system employed up to now. The transition to the absolute measuring system is also made possible according to requirements.
摘要:
A method of transferring printing ink from an intermediate carrier to a printing-ink receiver selected from the group consisting of a further intermediate carrier and a substrate, wherein the printing ink adheres either in a granular state or in an at least partially liquid state to the intermediate carrier includes, with respect to the first-mentioned state of the printing ink, melting the printing ink at a side thereof facing away from the intermediate carrier before transferring the printing ink to the printing-ink receiver and, with respect to the second-mentioned state of the printing ink, reducing the adhesion of the printing ink to the intermediate carrier with a separating agent at one time at least before and during transfer to the printing-ink receiver; and a device for performing the method.
摘要:
Method of controlling a printing device of a printing press wherein substrates to be printed are conveyed on a conveying path to the printing device, the conveyed substrates being detected by a sensor disposed along the conveying path, upstream of the printing device, as viewed in a conveying direction of the substrate, includes starting a printing operation whenever a leading edge of a respective substrate is detected, and stopping a printing operation whenever a trailing edge of the substrate is detected.
摘要:
Sheets of defined format lengths are printed in a sheet-fed rotary printing press with a plurality of printing units. Each of the printing units includes an impression cylinder and a counter-pressure cylinder. The two cylinders define a printing nip and the printing units are disposed such that a sheet travels through the printing nips in succession. The impression cylinders have a circumference which is no longer, and preferably shorter, than a shortest format length of the sheet. The impression cylinders are disposed such that mutually adjacent printing nips of adjacent printing units are spaced at a distance which is shorter than the shortest format length to be printed. The impression cylinders have a circumferential surface carrying a subject or motif to be printed. The images printed on printing material therefrom have an image spacing between one another. The circumference of the impression cylinder is smaller than the sum of the image length and the length of the image spacing.
摘要:
A sheet-fed printing press includes a plurality of printing units disposed along a sheet-transport path. A transport apparatus (3, 33, 40, 50, 66, 78) is disposed along the sheet-transport path. The sheets are transported through the printing units along the sheet-transport path and, after recto-printing, they are returned along a return-transport path which extends essentially in an opposite direction to the sheet-transport path. The printing press is thus enabled to print recto-and-verso while having a very short structural length.