Abstract: An apparatus to obtain ink density data by scanning color measurement strips on a printed sheet has a densitometer mounted on a digitally-driven X,Y positioning mechanism, an optical sensor for detecting the position and orientation of the sheet with respect to the X,Y positioning mechanism, and a numerical computer for transforming the sheet coordinates of the color measurement strips to the X,Y coordinates of the X,Y positioning mechanism. Thus, the numerical computer can automatically position the densitometer to scan the color measurement strips. In a first embodiment, optical sensor arrays determine the position and orientation of the test sheet with respect to the X,Y positioning mechanism. In a second embodiment, the densitometer itself scans the edge portions of the test sheet to determine the position and orientation of the test sheet.

Abstract: A machine for scanning printing plates to determine the ratio of "printing" to "non-printing" area for pre-adjustment of the ink dosing elements of a printing machine has an array of electronic photo-sensors, each sensor being disposed in a channel having low-reflection chambers which permit sharp delimination of resolution elements on the printing plate and ensure high definition scanning of different types of printing plates under practical conditions. Preferably the diaphragms dividing the channel into chambers have greater spacing at greater distances from the element sensed on the printing plate. To accommodate printing plates of different materials, means are provided for selecting the wave length of the light source. To prevent measurement error due to changes in the distance from the printing plate to the light source and sensor array, the photosensor array is preferably directed or aimed 60.degree. to 45.degree.

Abstract: An ink metering system for letterpress and offset printing machines is provided in which the duct roller, the ink vibrator discs and the transfer roller have a low circumferential speed and wherein the ink is accelerated by suitable vibrator devices to higher speeds corresponding to the circumferential speed of the plate cylinder. The ink vibrator discs are controlled under defined conditions by various lever systems in order that the ink may be transferred controllably and in optimum manner without any empty gaps. The ink vibrator discs can also be readily removed and fitted for repair and cleaning purposes.

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: 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: Apparatus for facilitating peripheral adjustment of a printing plate on a printing cylinder of a multicolor printing press in the form of an optical viewing device having magnifying optics including a single eye piece and two objectives. The objectives are spaced for simultaneous viewing of a peripheral reference mark at the end of the cylinder and an index mark on the plate which is positionally related to the image thereon. The optical viewing device has a screen including an optical reference, with the reference and index marks being superimposable thereon in the same field of view. In one form of the invention a calibrated scale is provided on the screen for direct measurement of the disparity in peripheral register between the two marks.

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.

Abstract: A delivery arrangement including a conveyor and take-off mechanism for delivering a series of printed sheets onto a pile in which nozzles are provided distributed along the width of a sheet, for directing a jet of air to the underside in a direction opposite the sheet movement. A guide plate spaced under the sheet and extending upstream from the nozzles serves to confine the jet. Formed on the surface of the guide plate are a plurality of upraised islands, spaced from one another over the area of the guide plate, the islands presenting plateau surfaces at approximately the same elevation above the guide plate. Consequently, when a sheet is sucked downwardly by the jet of air it engages the plateau surfaces in light frictional engagement to apply frictional drag to the body of the sheet. The source of pressurized air for the nozzles includes means for automatically varying the pressure, and hence the frictional drag, in accordance with the speed of the press.