Abstract: An apparatus and method for feeding a stream of underlap-imbricated sheet-like printing substrates to printing machine, the apparatus comprising a conveying table for conveying the stream in a conveying direction toward the printing, a source of compressed air, and at least one blowing device coupled to the source of compressed air, the blowing device being disposed in a region of the conveying table adjacent to printing machine, and including at least one opening disposed to direct compressed air beneath the imbricated stream in a direction opposite to the conveying direction.

Abstract: A conveying cable for conveying sheets includes a suction chamber with a supporting surface defining a shallow groove having a plurality of suction openings therein over which a perforated suction belt moves. A plurality of vent openings separately communicating with atmosphere are disposed adjacent the belt edges to prevent the sheets from being sucked against the table surface. The perforations in the suction belt preferably take the form of staggered slots which leave imperforate zones free along the center and adjacent the edges of the belt to help reduce undesirable belt stretching and the suction openings in the supporting surface increase in size adjacent the delivery end of the table.

Abstract: In order to improve mechanical positive synchronization in a sheet-fed printing machine between gripper carriages guided in wave-like fashion through printing units on endless chains and the associated impression cylinder, the impression cylinders (1) have twice the diameter of the plate and blanket cylinders (2, 3). Sprocket wheels (34), also of twice the diameter of the blanket cylinders, are fixed on the ends of the double-size impression cylinders (1) and on them there are disposed two diametrically opposite gripper carriage locating and fixing devices (24-32) which are adjustable both radially and tangentially and which can also be used to bring the different printing plates into register with one another on the printed sheet (38).

Abstract: To obviate local differences in heat expansion in the ink duct, ink metering means and ductor roller, and to temper the printing ink, stabilize the ink-damping agent emulsion and protect the ductor roller from corrosion, the ink duct includes a heat insulating material secured to underside of the duct body and a mid-section portion of the duct body side facing the ductor roller is supplied with a warm air flow from the printing press, boosted by a plurality of fans.

Abstract: A sheet feed drum for transferring sheets in a rotary printing press wherein the drum other contour is provided with an ink-repellent coating and two circumferentially spaced front and rear drum edges defining a duct therebetween which accommodates a sheet gripper system. The ink-repellent coating supporting a netting-like fabric relatively loosely thereon prevents any smearing of a freshly printed underside of a sheet during sheet feed on the drum while the sheet is engaged by the gripper system. Starting at the front edge of the drum, the outer contour of the drum is constructed in the form of a continuously increasing signal merging into a fixed drum radius whereby the netting-like fabric is contactable by the freshly printed underside of the sheet on the sprial first substantially flatly behind the front edge of the drum and then in any subsequent angle of rotation of the drum without the sheet tangent ever being bent or creased.

Abstract: An ink metering device for the fountain roller of a printing press including a plurality of ink slides in the ink fountain wherein each slide has a metering element of duct width movable by an adjusting screw which is connected to an adjusting pin and biased by a spring toward the fountain roller to produce a metering gap wherein the spring element is supported between a fixed part of the ink fountain and the metering element and a length-equalizing element is provided permitting transmission of an adjusting movement to the adjusting pin such that the lenth-equalizing action is effective only by overcoming the force of the spring element. In the preferred embodiment, the adjusting pin is rigid with the metering element and the other end is screwed into a length-equalizing coupling connected to a selective drive mechanism with the intermediate portion of the pin being supported for axial movement in a guide block.

Abstract: A sheet guiding device for use with a multicolor printing press having multiple printing units and a sheet stacker wherein the sheet guiding means is disposed between at least one of a pair of printing units and the stacker for guiding sheets therebetween, the guiding means including a chain conveyor with sheet grippers overlying a guide surface between the printing units and the stacker with a plurality of air nozzles formed in the surface of the guide surface and communicating with a plurality of flow ducts, the guide surfaces being disposed continuously and uninterruptedly between the printing units and the sheet stacker and the air nozzles being in the form of apertures in the guide surfaces having a diameter of about 15 mm, the area of the apertures being from 15 to 30% of the total guide surface area, the apertures being supplied by low-pressure high-volume-flow fans disposed in the flow ducts and the fans being reversible so that the nozzles can be selectively supplied with air at a positive or negativ

Abstract: An ink fountain for a printing press has a temperature-responsive element for compensating the adjustment of the spacing between the blade and the fountain roller to keep the thickness of the ink film fed by the blade substantially constant even under extreme temperature variations. The sub-frame of the ink fountain is pivotally mounted to the main frame of the printing press about a pivot axis generally parallel to the axis of the fountain roller, and the pivot angle is a function of the thermal expansion of the temperature-responsive element. In one preferred embodiment, the temperature-responsive element is elongated, received in a guide fixed to the sub-frame, and has a free end bearing against the bearing bushing of the fountain roller. In another embodiment, the temperature-responsive element is a side wall of the ink trough or is a plate parallel to the side wall of the ink trough, and rollers are journaled to the temperature-responsive element and bear against the surface of the fountain roller.

Abstract: A clamping device for thin flexible printing plates has a tensioning rail at the trailing wall of a wide longitudinal groove in the plate cylinder. The tensioning unit is mounted for axial and peripheral adjustment on a support of "L" cross-section having a first leg seated with respect to the bottom of the groove and a second leg presenting an upstanding reference surface interposed between the tensioning rail and the trailing wall of the groove. A set of tensioning springs recessed in the tensioning rail bear against the reference surface and apply peripheral tension to the plate. A spring detent latches the tensioning rail temporarily against the reference surface, overcoming the tensioning springs while the trailing edge of the plate is being gripped. The spring detent is mounted upon and movable with the support. Screws having a plurality of selectable holes anchor the support in a series of peripheral positions for accommodation of plates of different length.

Abstract: For use with an ink fountain having a trough with a flat sloping bottom wall and a fountain roller at the presented edge of the bottom wall, a moveable partition for dividing the trough into adjacent feeding and non-feeding areas. The partition consists of a trough-engaging portion having a straight face for engaging the bottom wall of the trough and a separate roller-engaging portion having an arcuate face for engaging the roller surface. Resilient sealing strips are secured to the faces thereof for sealing against the flat bottom wall of the trough and the cylindrical surface of the roller. The two portions are so arranged that their adjacent edges overlap to block the escape of ink, and are connected one to the other by a pivot which extends parallel to the roller axis in the region of the overlap.

Abstract: An ink fountain including a frame defining a horizontal slot adjacent the fountain roller. Arranged side by side in the slot is a metering assembly in the form of a series of flat slides each having a cam assembly at its rear end for adjusting the position of the slide with respect to the fountain roller thereby to meter ink in predetermined thickness in respective zones. Each slide is formed of a body having secured thereto a rectangular tip portion formed of resilient plastic. The tip portion of each slide has embedded in it a blade of wear resistant spring metal, the blade being coextensive with the width of the slide and so oriented as to present a flat face to the fountain roller defining, with the fountain roller, a sharply acute cusp.

Abstract: An automatic ink feed control for a printing machine. Several ink-dosing elements are arranged across the width of the printing machine for dosing the application of ink to a printing plate, and these ink-dosing elements are individually adjustable by an adjusting device. The ink density of several control areas on the printed material is measured by a scanning measuring device, and a computer control compares these measured ink densities to desired ink densities in order to effect control of the adjustment of the ink-dosing elements by the adjusting device.

Abstract: A mechanism for securing and tightening a blanket on a cylinder of a printing press, particularly an offset press, which includes a rockable clamping shaft mounted in the groove on the cylinder together with a movable jaw member on the shaft, the jaw member being rockable between open and closed positions about an axis which extends longitudinally adjacent the surface of the shaft, so that when the shaft is in a reference position and the jaw member is open, an entryway is created which faces chordwise of the cylinder. The jaw member is held open against a force of bias by a stop surface on the cylinder for reception of a reinforcing bar at the end of the blanket, but when the shaft is manually rotated away from its reference position the jaw is automatically closed to capture the bar following which the bar is swung in a direction to tighten the blanket.

Abstract: An ink roller for a printing press having a cylindrical outer shell presenting a roller surface and having a control fluid-displacing core, a hollow cylindrical partition being interposed between the shell and the core to define inner and outer annular passageways connected in series having respective inlet and outlet openings. A source of cooling fluid is connected to the inlet opening so that a feed stream of cooling fluid flows longitudinally through the inner passage and turns around to form a cooling stream flowing in counterflow relation through the outer passage. The cylindrical partition is formed of conductive material so that heat absorbed at a given region of the roller surface by the cooling stream flows radially inwardly for absorption by the feed stream at substantially the same rate, so that the cooling stream has only minimum net gain or loss of heat; this tends to equalize the temperature along the length of the cooling stream and hence along the length of the roller surface.

Abstract: A control system for a reversible screwing tool for tightening and loosening screws in a printing press or the like which includes a pair of angularly spaced pick-up devices coupled to the shaft of the tool for generating respective series of impulses. Monostable pulse generators are coupled to the respective pick-up devices, the generator coupled to the pick-up device in leading position, for counterclockwise rotation, being set to produce an output pulse which is substantially wider than that produced by the generator which is connected to the pick-up device in trailing position so that during counterclockwise rotation the output pulses from the generators timingly overlap one another. The generators feed into the input terminals of an AND gate which is, in turn, connected to a counter which counts the pulses resulting from counterclockwise rotation of the shaft.

Abstract: An ink fountain having a metering assembly in the form of a series of rectangularly shaped slides fitted into a horizontal slot in a frame with only the presented front ends of the slides being exposed and abutting the fountain roller. The slides are arranged side by side in coplanar relation with their lateral edges lying closely adjacent one another. Notches are formed in the lateral edges of the slides adjacent the front ends thereof, with the notches being occupied by slightly oversized buttons of resilient sealing material. The metering assembly is held captive at its ends between two vertical end plates which apply inward squeezing pressure to the metering assembly so as to compress the resilient buttons uniformly to bring the lateral edges of the slides into snug sliding relation to prevent leakage of ink between them and for the purpose of distributing any cumulative tolerance error equally between all of the slides in the series.