Abstract: In order to compensate for slippage of a printing-plate sleeve on the plate cylinder of a printing unit having its own motor, a first reference point for the position of the printing plate is sensed by a sensor. The first reference point is then compared with the position of a reference printing-plate sleeve of a reference printing unit. A motor during the printing unit is then readjusted when there is a determined deviation from the desired position.

Abstract: A folding device in which printing-material webs are cooled in an effective manner includes guide rollers and/or feed rollers designed as cooling rollers. Alternatively or in conjunction with the cooling rollers, there are cooling arrangements in the folder superstructure and compressed cooling air flows from these cooling arrangements onto the surfaces of the printing-material webs.

Abstract: Disclosed is a film roller in an inking unit of a rotary printing machine. The film roller is equipped with an internal cooling system to eliminate irregularities in the ink transfer to the film roller and to improve print quality.

Abstract: The present invention relates to a printing unit for blanket-to-blanket printing. The printing unit includes two printing couples positioned one on top of the other. Each printing couple includes a form cylinder and a transfer cylinder. The transfer cylinders each carry a gap-free blanket. A horizontal web passes between the transfer cylinders of the two printing couples. In order to achieve good print quality with an advantageous web path, a plane connecting the centers of the transfer cylinders is inclined from a plane extending perpendicular to the web and passing through the center of one of the transfer cylinders by an angle (.alpha.) in the range from 0.degree. to 10.degree. and optimally by an angle of 5.degree..

Abstract: To permit flying plate change of printing plates (14, 15; 28, 29) on plate cylinders (10, 11; 24, 25) of an offset printing system having blanket cylinders (1,2), one of which can function as an impression cylinder (2, 1), the plate cylinders, to maintain register, are axially fixed in the frame (3) of the printing machine, but the blanket cylinders are movable by an eccenter system between three positions (6, 7, 8) and an ink application roller (16) to which also damping fluid can be applied from a damper (20) is selectively engageable with either one of the plate cylinders. Thus, only the blanket cylinder (1, 2) and the associated impression cylinder (2, 1) need be shifted for respective engagement with the plate cylinders, and register alignment of the plate cylinders is maintained. An ink application roller is selectively engageable with the plate cylinders, for example by being supported on a swing shaft or a swing lever (17), with which also a damping fluid application roller (19) is engageable.

Abstract: A safety guard rail (7) can be moved between a position adjacent a nip between two rotating cylinders (3, 4) and a remote position. The safety guard rail has flanges (8, 9) attached thereto, projecting essentially parallel to cover plates (5, 6) already present in the printing machine. The cover plates are formed with guide slits (12, 13) extending downwardly at an inclination, in which guide elements (10, 11) engage, secured to the projecting flanges which hold the safety guard rail (7). Limit switches are coupled to be engaged by the flanges and/or the guide elements to provide ON and OFF signals, in dependence on the position of the safety guard rail with respect to the nip, to inhibit printing machine operation when the guard rail is in a remote position, for example for changing of rubber blankets on the cylinders, and permitting printing machine operation only when the safety guard rail (7) is adjacent the nip to be able to carry out its safety guarding function.

Abstract: Lateral escape of ink from between the end face (A) of a duct roller (1) and the side wall (3) retaining the duct roller is prevented by extending the length of the duct blade (11) beyond the axial extent of the duct roller and placing an end wall portion (4) in the end wall which is resiliently pressed against the end face (A) of the duct roller and, further, resiliently engaged with the top face of the duct blade (11) to form a tight seal and prevent escape of ink laterally from between the duct blade (11) and the duct roller (1). The resilient portion is plate-like, and the sealing strip preferably is a generally T-shaped element, in which the leg portion of the T is clamped to both the resilient portion (4) of the end wall and the fixed portion (3) thereof, while permitting relative movement of the two elements.