Abstract: The invention relates to a method for operating a printing press, particularly a sheet-fed offset printing press, wherein at least two drives, whose positions can be controlled independently from each other, feed into a continuous gear train of the printing press. A desired torque distribution for the drives feeding into the continuous gear train is determined such that each drive provides a driving torque for the associated sub-unit of driven devices and in part for the sub-unit of driven devices associated with a drive connected downstream of the respective drive, wherein based on said torque distribution for each drive an individual angle target value is determined, which is used to control the position of each drive individually in order to provide an angular difference that is dependent on the torque distribution between the feed sites of the drives.

Abstract: The invention concerns a method for controlling a machine for processing sheet material that has at least one individually driven cylinder. The method involves interrupting a pressure contact in a contact zone between a plate cylinder 10 as a directly driven cylinder and a neighboring rubber blanket cylinder 8. The plate cylinder 10 is then turned by the direct drive from its particular angular position into an angular position in which a first printing plate located on the plate cylinder 10 can be removed. The first printing plate is then removed from the plate cylinder 10 and a second printing plate is brought up and secured to the plate cylinder 10. The plate cylinder 10 with the second printing plate is then turned by the direct drive into an angular position appropriate for the printing process.

Abstract: The invention relates to a method and a device for controlling a processing machine for sheet-like material having at least one cylinder that can be driven individually and that carries a printing form. The method involves, inter alia, eliminating the pressurized printing contact between the plate cylinder 10 and adjacent rubber blanket cylinder 8 and for cleaning processes the inking unit rollers are separated on the drive side from the main drive and gear train of the sheet-guiding cylinder 6 and temporarily coupled with the directly driven plate cylinder 10. The plate cylinder 10 and inking unit rollers are driven at a first rotational speed and the rubber blanket cylinder 8 and the adjacent sheet-guiding cylinder 6 are driven at a second rotational speed by the main drive and gear train.

Abstract: A drive for a sheet-fed printing machine, in particular a sheet-fed offset printing machine is described, in which the individual cylinders and/or drums and the plate or form cylinders are driven by a common drive train. In order to allow automated operations to proceed simultaneously, clutches are arranged in the drive trains of the individual plate or form cylinders and, furthermore, the individual plate or form cylinders are assigned drive motors which can be controlled separately and by means of which the plate or form cylinders can be driven in the intended manner after corresponding disengagement.

Abstract: A printing machine is disclosed, in particular a sheet-fed offset printing machine, in which a plurality of cylinders are coupled to one another via a continuous drive train, and at least two cylinders include a controllable drive. The controllable drive stresses the drive train in order affect the tooth-flank contact of the gear train, which affects the angular position of the printing cylinders. By controlling the angular positions of the printing cylinders, precise registration is maintained during dynamic changes in the load on the gear train during the printing process. More specifically, blanket cylinders in the printing machine are each coupled to a position-controllable drive, which is controlled by applying a preferred position value in such a way that the gear train placed between two drives is stressed by a predefined angular amount.

Abstract: A drive system for a sheet-fed offset printing press in which one or more cylinders are motor-driven in accordance with a prescribed desired position. According to the invention, a correction device receives measured angular position values of the cylinder from a rotational position sensor. The correction device then converts the measured position values into modified position values which are then sent to the drive controller. The drive controller compares the modified position values with desired cylinder position values and controls the motor so as to correct any deviation between the values. The correction device allows modification of the measured signals as needed to compensate for known or determinable parameters. A drive according to the present invention provides precise driving control, while reducing the required assembly and manufacturing accuracy of components such as the angle position sensor, and while compensating for other errors in drives.

Abstract: A drive is provided for a sheet-fed offset printing press having multiple printing units. Each printing unit has printing cylinders which are independently driven. Transfer drums are driven mechanically uncoupled from the printing cylinders, and may be interconnected by a single gear train, or the transfer cylinders of each printing unit may be independently driven by a respective drive. Other rollers in the printing units may have individual controllable drives also. The invention minimizes disturbances caused by load fluctuations in conventional printing presses wherein the printing and transfer systems are mechanically intercoupled. The invention also is cost effective, particularly for register corrections. According to the invention, at least the plate cylinders are driven individually with respect to the sheet-transfer system or the corresponding blanket cylinder.

Abstract: A method and apparatus for controlling a multiple motor drive arranged to drive printing cylinders of a printing machine sychronously decelerates each of the drives upon a failure or defect occurring in one or more of the components of the drive system such that the individual printing cylinders are decelerated in a manner synchronized with one another with respect to rotation angle. The apparatus includes a main control device which detects a failure in one of the drive system components and controls the drive units to decelerate the drive units to a standstill in accordance with a time function. The time function is determined by the rotation of the drive unit which contains the component that failed.

Abstract: An undershot inking unit and associated method are disclosed. The undershot inking unit includes an ink fountain roller that is controlled independently of the printing speed of the printing machine, and in which the rotational contact angle of the distributor roller on the ink fountain roller is varied according to the printing unit speed. The method comprises controlling the rotational speed of the ink fountain roller independently of the printing speed of the printing machine; and varying the rotational contact angle of the intermittent ductor roller on the ink fountain roller according to the printing speed of the printing machine. In a preferred embodiment, the apparatus includes two coaxial cams rotatably adjustable with respect to each other. Each cam includes a predominant circumferential contour and a subordinate circumferential contour.

Abstract: An undershot inking unit and associated method are disclosed. The undershot inking unit includes an ink fountain roller that is controlled independently of the printing speed of the printing machine, and in which the rotational contact angle of the distributor roller on the ink fountain roller is varied according to the printing unit speed. The method comprises controlling the rotational speed of the ink fountain roller independently of the printing speed of the printing machine; and varying the rotational contact angle of the intermittent ductor roller on the ink fountain roller according to the printing speed of the printing machine. In a preferred embodiment, the apparatus includes two coaxial cams rotatably adjustable with respect to each other. Each cam includes a predominant circumferential contour and a subordinate circumferential contour.

Abstract: A system and method for controlling the lifting of a stack of sheets to be printed in order to keep the currently uppermost sheet of the stack within a certain predetermined height range for reliable removal to a feed table. A motor is operated in either a discontinuous mode or in a continuous mode to lift the sheets, the mode of operation being chosen in dependence on the speed of the press and the thickness of the sheets when compared against an established curve. A sensor is utilized to determine the vertical position of the uppermost sheet in the stack. In the continuous mode the motor speed is adjusted in accordance with the height of the uppermost sheet in the stack, while in the discontinuous mode, the motor is energized and de-energized such that the height of the currently uppermost sheet in the stack is maintained within a predetermined height range.