Roland Offsetmaschinenfabrik Faber & Schleicher Ag

Kurt Difflipp

Friedrich Preuss

A device for the lateral and longitudinal positioning of sheets on the feed table of a printing press, with the leading edge of the sheet engaging a set of front stops and the lateral edge of the sheet in contact with a side guide, enabling accurate registered pick up by a transfer cylinder or the like. Cooperating laterally swingable wiper members are provided both above and below the sheet having friction shoes for wiping the sheet in the direction of the side guide. The friction shoes are connected to the respective wiper members in such a way as to provide freedom of relative movement at right angles to the direction of wipe so that the sheet may move against the front stops at the same time that is being wiped toward the side guide. In the preferred embodiment of the invention the wiper members are in the form of synchronously rotated arms timed so that the arms engage the sheet as the sheet approaches the front stops, and the friction shoes are in the form of rollers interposed at the ends of the arms, freely rotatable about axes which extend in the direction of wiping movement, so that the sheet may complete its movement against the front stops, with accommodating rotation of the rollers, as it is being urged by the rollers toward the side guide. In an alternative embodiment the friction shoes are stiffly secured to the wiping members in the wiping direction but supported with light resilient force in the direction of movement of the sheet so as to permit final movement of the sheet simultaneously in the two directions.

Side-registering device

A sheet-fed printing press installation comprised of a first press unit for printing on one side of a sheet and which is coupled by a chain type conveyor to a second press unit in which there is a transfer drum having a normal set of grippers and an auxiliary set of grippers for (a) additional printing on the same side of the sheet or (b) printing on the opposite side of the sheet. The conveyor has an inlet sprocket for taking of the sheet from the impression cylinder in the first press unit and an outlet sprocket for delivering the sheet to the impression cylinder in the second press unit. First and second transfer drums are interposed in series between the outlet sprocket and the impression cylinder of the second press unit, the first transfer drum having the normal and auxiliary set of grippers. When the auxiliary set of grippers is activated, the sheet is gripped at the trailing edge thereby to reverse the sheet for printing on the second side of the sheet in the second press unit. The sprocket chain is driven at a speed which is less than the peripheral speed of the first transfer drum so that the auxiliary set of grippers may remove the sheet more promptly from the conveyor and sprocket drum to avoid smearing of the printed side of the sheet. A vacuum type sprocket drum preserves accurate register of the sheet for gripping purposes and stationary vacuum plenums are provided for removing the sheet from the influence of the drum just prior to transfer from the conveyor to the first transfer cylinder.

Multicolor sheet-fed printing press

Sheet coating means for a printing press including a back-up cylinder and form cylinder having an associated fountain, the fountain having a fountain roller rotating adjacent the form cylinder. Also rotating adjacent the form cylinder is a first form roller which is coupled to the fountain roller via a dosing roller. The fountain and its associated rollers are mounted upon a subframe having provision for (a) shifting the fountain roller into liquid transmitting contact with the form cylinder and (b) shifting the first form roller into liquid transmitting contact with the form cylinder thereby, selectively, to change the length of the liquid transference path from the fountain to a sheet carried by the back-up cylinder in accordance with the drying speed of the coating material. In a preferred embodiment the fountain assembly includes a second form roller rotating adjacent the back-up cylinder for transmitting coating material directly from the fountain roller to the sheet thereby bypassing the form cylinder, extending the capability to use with coating materials of a viscous nature. Also in a preferred embodiment the fountain roller is driven by means separate from the press drive thereby to control the rate of application.

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Dietzenbach, Germany

Kurt Difflipp