Abstract: 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

Abstract: Safety device for control or regulation systems of drive units of a printing machine having at least individual sub-aggregates thereof mechanically disconnected from one another, a plurality of motors connected via respective gear transmissions to the sub-aggregates for driving them in synchronous rotation, at least one measuring device for ensuring synchronous running of the sub-aggregates, and a device for controlling the rotary speed or the torque of the motors connected to the measuring device, further includes a clutch disposed between the gear transmissions of two of the at least individual sub-aggregates located adjacent one another, the clutch having clutch halves respectively connected to a synchronously running gearwheel of the respective gear transmissions, the clutch halves being connected to one another for transmitting torque when a preset rotational-angle difference between the clutch halves is exceeded.

Abstract: 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 monito

Abstract: 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.

Abstract: 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.

Abstract: 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.