Other

Air Systems, Inc.

Milton R Lemaster

Norman H Kemp

James R Day

Separate air curtains of low pressure, high flow volume air are discharged onto the leading inking form roller on the feeder side and onto the trailing inking form roller on the delivery side of the plate cylinder to evaporate water entrained with the ink and which has migrated from the printing plate to the inking form rollers as a result of uneven application of water to the plate cylinder. A pair of elongated distribution manifolds are mounted on the press in proximity to the inking form rollers, one manifold directing a curtain of air onto the inking form roller and adjacent vibrator roller on the feeder side, and the other manifold directing a curtain of air onto the inking form roller and adjacent vibrator roller on the delivery side of the plate cylinder. Gap streak caused by periodic interruption in the transfer of dampening solution to the printing plate is eliminated by the dual air curtains which evaporate dampening solution picked up from the printing plate by the inking form rollers before the excess dampening solution has an opportunity to infiltrate the inking roller train.

Dual air curtain apparatus for reducing infiltration of dampening

An apparatus and method for oscillating the ink form rollers and dampening form roller in a lithographic printing press to apply a smooth, relatively uniform coating of ink to the ink-receptive areas of the lithographic printing plate and to prevent ink from being transferred from the dampening form roller to the ink-rejecting areas of the printing plate. The ink form rollers and the dampening form roller are each mounted on a shaft rotatable about its own axis. The shaft has at least one shaft key for mating with a complementary keyway in a bushing which is inserted at least partially into the central opening of the corresponding roller. The engagement between the shaft key and the bushing keyway allows the roller and bushing to engage the shaft for common rotation while permitting the roller and bushing to slide axially with resepct to the shaft. First and second collar members may be disposed at respective predetermined locations on the corresponding shaft for limiting the axial movement of the corresponding roller between selected limits, although both the ink form rollers and the dampening form roller are preferably allowed to oscillate axially substantially the same distance in each direction as the corresponding vibrating roller by which the oscillating motion is imparted thereto.

Apparatus and method for oscillating the form rollers in a printing press

An apparatus and method for oscillating the dampening form roller in a lithographic printing press to provide a substantially uniform application of dampening fluid on the printing plate. The form roller is comprised of a rotatable shaft and a cylindrical roller concentrically disposed on the shaft. A double-ribbed barrel cam is coupled to the roller so as to be rotatable therewith and first and second cylindrical cam followers are disposed a predetermined distance apart on the shaft for receiving the cam therebetween so that a first major surface of the cam is in contact with the first cam follower and a second major surface of the cam is in contact with the second cam follower. The 'rise and fall' of the cam as the cam rotates relative to the cam followers imparts an oscillating motion to the roller. The rate of oscillation is substantially the same as the rate of rotation of the cam relative to the cam followers. The rate of oscillation is controlled by means of first and second roller bearings which are proximately disposed on the shaft. By adjusting the frictional engagement between the respective inner and outer races of the bearings, the speed of the shaft is controlled. The greater the relative difference between the rotational speed of the roller and the rotational speed of the shaft, the greater will be the rate of oscillation because the cam will rotate at a greater speed relative to the cam followers. Conversely, a lesser relative rotational speed differential between the shaft and roller will result in a lesser rate of oscillation of the roller.

Oscillating form roller and apparatus and method for controlling the

An apparatus and method for oscillating the ink form rollers and dampening form roller in a lithographic printing press to apply a smooth, relatively uniform coating of ink to the ink-receptive areas of a lithographic printing plate and to prevent ink from being transferred from the dampening form roller to the ink-rejecting areas of the printing plate. The ink form rollers and the dampening form roller are each comprised of a hollow cylindrical metal core surrounded by a rubber covering. First and second bronze bushings are partially inserted into the hollow core at respective opposite ends of the roller. Each roller is mounted on a shaft rotatable about its own axis. The shaft has first and second shaft keys for mating with complementary first and second keyways formed in the respective first and second bushings to allow the bushings to engage the shaft for common rotation while allowing the roller and bushings to slide axially with respect to the shaft. First and second collar members are disposed at respective predetermined locations on the shaft for limiting the axial movement of the roller on the shaft between selected limits. The ink form rollers and dampening form roller are each rotated and moved axially substantially in unison with the rotation and axial movement of the corresponding vibrating rollers, thereby substantially eliminating 'ghosting' and 'tracking'.

An apparatus and method for oscillating the form rollers in a lithographic printing press to apply a smooth, relatively uniform coating of ink to the ink-receptive areas of a lithographic printing plate. The apparatus is comprised of a shaft rotatable about its own axis and a roller concentrically disposed on the shaft. The roller is preferably comprised of a hollow cylindrical metal core surrounded by a rubber covering. First and second bronze bushings are partially inserted into the hollow core at respective opposite ends of the roller. The shaft has first and second shaft keys for mating with complementary first and second keyways formed in the respective first and second bushings to allow the bushings to engage the shaft for common rotation while allowing the roller and bushings to slide axially with respect to the shaft. First and second collar members are disposed at respective predetermined locations on the shaft for limiting the axial movement of the roller on the shaft between selected limits. In the preferred embodiment the apparatus is installed as a form roller device in a lithographic printing press. The form roller is rotated and moved axially substantially in unison with the rotation and axial movement of the corresponding vibrating roller.

A system for dehydrating the inking roller system of a lithographic rotary printing press includes providing a flow stream of pressure air or other dry gas across the inking roller system to evaporate water entrained with the ink and which has migrated from the plate cylinder through the inking roller system as a result of application of water to the plate cylinder. An elongated distribution manifold is mounted on the press in proximity to the inking roller distribution system and preferably in proximity to one or more of the vibratory rollers in direct contact with the inking rollers engaged with the plate cylinder.

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Dallas, TX, United States of America

Milton R Lemaster