Device for the registering of sheets in printing presses in which the

Abstract

A device for registering of sheets, received in an underlapped stream, upon a feed table. The feed table has a retractable front stop and a side guide defining a condition of accurate register for the sheet. Cooperating with the side guide is a wiping mechanism which includes a lower wiping member and a cooperating upper wiping member for engaging a sheet between them for wiping the same into laterally registered position. A pre-gripper grips the leading edge of a registered leading sheet for transporting it forwardly and upwardly to a receiving cylinder thereby forming a wedged-shaped gap above the following sheet. Upon formation of the gap the upper wiping member is momentarily inserted into the gap in active wiping position, with the result that the following sheet is fully registered while it is still partially covered by the leading sheet. The front stop is mounted for swinging movement and so arranged that upon moving to active position it engages the underside of the leading sheet at a point spaced above the table thereby insuring the presence of a well-defined gap for entry by the upper wiping member. In one embodiment of the invention the upper wiping member is mounted upon a rotatable arm for moving the member quickly into and out of the gap while providing a limited amount of dwell in wiping position. In a second embodiment the upper wiping member is mounted upon an arm which reciprocates inwardly and outwardly of the gap.