Abstract: A cam mechanism is described for automatically skewing a second cylinder in a printing press, such a form roller (24), in response to skewing of a first cylinder thereof, such as a plate cylinder (12), and for throw-on/throw-off of the second cylinder. The mounting (80, 82) for each end of the second cylinder is biased against a corresponding cam (74, 76), both cams being carried on a common cam shaft (78). A linkage (90) couples the cam shaft (78) to an eccentric (52) used for skewing the first cylinder (12). Upon skewing of the first cylinder (12), the linkage (90) rotates the cam shaft (78). The profiles of the cams (74, 76) are selected to be different so that this rotation of the cam shaft (78) causes one end of the second cylinder (24) to move to a greater extent than the other end, thereby skewing it by an amount matching the skewing of the first cylinder.

Abstract: Selective reduction in ink tackiness resulting in better ink transfer with less print through better image reproduction fidelity, less plate wear, less waste of paper, and less linting may be accomplished by selective warming of the image areas on the printing plates prior to application.

Abstract: The disclosed system controls, through novel pressure and valving adjustment mechanisms, the application of dampening fluid to the ink roll or offset plate on the plate cylinder of an offset printing press. The dampening fluid passes through a pressure compensator which adjusts the fluid pressure in response to changes in the speed of the press. The fluid at the adjusted pressure is then directed to a spray bar, where it is discharged through a plurality of nozzles. The fluid is directed to the spray bar by a multiple valve, page control assembly. In the page control assembly fluid from a common manifold is discharged through a plurality of dual control valves to respective nozzles. Closure elements for the respective valves are operated by air pistons. A plurality of needle elements for the respective valves are axially adjusted by a common manual control so that adjusting the manual control adjusts the amount of fluid from one segment of the spray bar, preferably corresponding to a full page.

Abstract: A method and apparatus for controlling dampening water utilized to form a thin film on the printing roll of the type, wherein the dampening water is circulated through the printing machine and a water tank, the level and temperature of the dampening water being maintained at definite values. Furthermore the pH value of the dampening water is measured and an acid or alkali is added to the dampening water in accordance with the result of the measurement so as to control the pH value at a definite value.

Abstract: A moisture control feed system of the bare-back type in which there is in nip-contact with a moisture transfer roll and the moisture transfer roll is driven solely by the shear resistance offered by the intervening layers at the nip of the ink and the moisture. The system includes an ink reservoir that simulates an oleophilic image in the form of a narrow strip extending transverse the direction of rotation of the master cylinder and is located outside the master retention area to supply ink to the oleophilic moisture form roll. The simulated image maintains the proper ink layer thickness on the oleophilic moisture form roll and the ink quality to assure proper rotational speed control of the transfer roll.

Abstract: A nitrile-containing material is bonded to the surface of a rubber substrate in order to increase the wettability of the surface. A rubber substrate is placed in the afterglow region of an electrodeless glow-discharge chamber. A nitrile-containing material such as an acrylonitrile monomer is introduced into the chamber, causing the monomer to polymerize and bond to the surface of the rubber substrate. In one embodiment, the surface of the rubber is etched with sulfuric acid prior to bonding the nitrile-containing material to the surface.

Abstract: A duplicator system and method are provided for preparing a lithographic master and for producing duplicated copies from the master in a fully automated system. An ink and moisture system is provided for supplying ink and moisture to a master on a master cylinder. During a pre-inking phase, an ink ductor roller is operative for a predetermined duration within variable ranges, as determined by the number of duplicated copies to be reproduced, and a moisture roller is operative to transmit moisture to the inking system. An early moisture circuit is also provided for conditioning the system by supplying moisture prior to a pre-inking phase in those instances wherein there has been a significant delay between the processing of two consecutive masters. Control means including a sensing device is provided for sensing the ambient temperature at an ink fountain and providing an indication thereof at predetermined temperature values.

Abstract: The disclosed system controls through novel pressure and valving adjustment mechanisms the application of dampening fluid to the ink roll or offset plate on the plate cylinder of an offset printing press. In one embodiment the dampening fluid at a relatively high pressure passes through a pressure compensator which adjusts the fluid pressure in response to changes in the speed of the press. The fluid at the adjusted pressure is then directed to the spray bar of the system, where it is discharged through a plurality of spray nozzles controlled by a plurality of solenoid-actuated valves. In one embodiment, the valves continually fluctuate between open and closed positions, with the time of the fluctuations being adjustable in order to selectively and accurately meter the amount of dampening fuid applied to the offset plate on the plate cylinder of the press.

Abstract: The amount of water present on a lithographic printing plate during printing is determined by measuring the amount of water present on a surface which is other than that of the printing plate but which carries an amount of water related to the amount of water present on the printing plate. The surface upon which the measurement is made may be the surface of a control pad mounted on the printing roller in the gap between opposite ends of the printing plate, the surface of one of the rollers of the damp train applying water to the printing plate, or the surface of an auxiliary roller contacting one of the rollers of the damp train applying water to the printing plate. The amount of water subsequently applied to the printing plate may be regulated in dependence upon the amount of water determined as being already present on the printing plate.

Abstract: A multiple spray nozzle, offset press dampening system of the type having individual metering pumps for the respective nozzles utilizes a device for opening the pump output valves while maintaining dampening liquid feed pressure substantially elevated, thereby purging feed lines, pump passageways and pump chambers of bubbles and particles which would interfere with accurate metering. Constant recirculation and filtering of the feed liquid under pressure maintains purging liquid substantially bubble and particle free.

Abstract: A device is provided for moistening the plate cylinders of offset printing machines. The device includes an inner rotatable sleeve having an air passage extending therethrough. Angularly extending passages are provided in the inner sleeve. The inner sleeve is rotatable within an outer fixed cylinder having spaced apertures all directed in the same direction. A film of water flows over the fixed cylinder. As the inner sleeve rotates air is forced through the inclined passage to force the water against a focus upon a diffuser which breaks the water up into a fine spray which is deposited upon the surface of a water cylinder so that the water is deposited from end to end thereof so that the plate is provided with a film of water throughout its length.

Abstract: In an arrangement for regulating the moistening solution mixture for use in an offset printing press, a tank is provided with two separate spaces, one for the moistening solution mixture and the other for a moistening solution additive. A conduit system containing various regulating devices is connected to the tank for regulating the introduction of the additives into the mixture and for the supply of the solution to the printing unit, a crystal sand filter is located in the conduit system for filtering the mixture and a pump, associated with the filter, directs a part of the filter mixture to the printing unit and returns a part of the mixture to the tank. A flow measuring electrode is arranged in the conduit system and is operatively connected to the regulating devices for controlling operation of the arrangement.