Abstract: A device for transporting sheets within a printing machine in which the sheets are conveyed by gripper carriages which are articulated on endless chains driven by chain wheels. A transfer of the sheets between the gripper carriages and a sheet-guiding cylinder takes place in the region of the chain wheels. The chain wheels, around which the chains are guided do not have a continuous shaft, but are attached to the opposing ends of short stub shafts which are mounted rotatably in the frame side walls of the printing machine. Attached to the other ends of the stub shafts stubs are gear wheels which mesh with gear wheels attached to the two journals of the sheet-guiding cylinder in order to synchronize the chain wheels with the sheet-guiding cylinder. A feed and take-off transport device of this type operates in such a way that a freshly printed sheet or a sheet provided with varnish coating can be transferred to and/or removed from the sheet-guiding cylinder in a smear-free manner.

Abstract: A device for monitoring sheet movement near the lay marks of sheet-fed offset printing presses. To ensure that a sheet has sufficient time to settle on the lay marks, the invention automatically selects between two instants at which sheet position is detected based on the state of the press (printing on or printing off). Since, depending on the state of the press, different procedures are performed before printing, selection of different instants of sensing provide a sheet the maximum amount of time possible for settling before detection.

Abstract: An improved sheet-feed drum for guiding and transferring sheets in a rotary printing press is provided with a plurality of round brushes rotatably mounted in closely spaced relation on a plurality of longitudinally extending supporting rods disposed about the periphery of the drum substantially parallel to the drum axis. The brushes are disposed on the support rods over the entire width of the sheets and have bristles made of an ink-repellent material.

Abstract: A device for turning over sheets in rotary presses of in-line construction, in which the impression cylinders of consecutive printing units cooperate with a single double-size transfer drum with which a storage drum is associated and gripper transfer facilities are provided which consist of cooperating rows of clamping grippers including fixed-position first-printing grippers cooperating with clamping grippers of the storage drum for turning the sheet over at the transfer drum, second-printing grippers which are adjustable with respect to the sheet format, and smoothing devices adjustable with respect to the sheet end are disposed after the clamping grippers on the storage drum as viewed in the direction of rotation.

Abstract: The amount of travel and the phase of axial reciprocation for sets of distributing rollers provided on each of at least two inking units of a rotary printing unit are independently adjustable from a central location. For each of the inking units, one eccentric drive adjustable in reciprocating phase and in the stroke or amount of travel is connected to the end portion of an impression cylinder twice the size of associated plate cylinders so that the axial reciprocating movements of the distributing rollers are derived in synchronism with the rotation of the impression cylinder and in a ratio of 1:2 to the rotation of the associated plate cylinders. In one embodiment, a single bolt clamps the two eccentric drives one on top of the other to the end portion of the impression cylinder. In another embodiment, the two eccentrics drives are concentrically arranged in ring-fashion to permit separate clamping and unclamping of each of the four independent adjustments of the amount of travel and phase of reciprocation.

Abstract: A safety device has pivotally mounted rails for guarding impression cylinder nips in a sheet-fed rotary printing press. The guard rails are pivoted from a guard or safety position during maintenance to a second position away from the impression cylinder during printing to insure that the printed sheets are not smeared by the edges of the guard rails. The guard rails, however, also sense operator contact during maintenance to cause the inching drive of the press to shut off immediately. A hinged access cover or door on the press shields the impression cylinder and cooperating cylinder during printing, and is opened to perform maintenance. Opening of the access cover operates an electrical switch for shutting off the main drive of the press, and the access cover is mechanically connected to the guard rails by a resilient linkage which in turn causes pivoting of the guard rails toward their safety positions.

Abstract: In a paper transport conveyor from a sheet feeder to a printing machine, the sheets are underlapped for speed reasons and for this purpose, the sheets are held and transported in a defined position using a conveyor table to which a vacuum is applied. In order to optimize the feed register in the printing machine in all states of operation, an additional conveyor device holds the sheets at the front gauges and aligns them. The vacuum at the conveyor table is quantitatively variable and the vacuum is so controlled according to operation as to be applied when sheets are required to be held on the conveyor table but interrupted when its action would obstruct the sheet alignment on the conveyor table.

Abstract: A method and apparatus for aligning and feeding sheets for printing presses having a conveyor for supplying the sheets individually from a feed stack to the front and side lays in a feed table of the press. The method includes the steps of causing the sheets to strike the front lays, drawing the sheets against a side abutment of the side lay, engaging the sheets from below utilizing a vacuum device and then again pressing the sheets against the front lays.The apparatus includes a vacuum device and front and side lays. The vacuum device includes suction arms disposed below the sheets and ahead of the front lays with respect to the direction of the sheet movement. The front lays are movable reciprocably in the direction of the sheet movement while the side lays are movable transversely to the direction of the sheet movement.

Abstract: A conveyor for sheets fed to or from a printing press in an overlapped stream, the table having longitudinal slots formed therein laterally spaced from one another. A perforated endless conveyor belt is trained over the table. An enclosed chamber extending substantially the length of the table communicates directly with the slots, the chamber being convergently shaped terminating at its lower end in a throat. An axial flow fan in the throat draws air through the perforations so that a stream of overlapped sheets on the belt will be held in contact therewith for transport from one end of the table to the other. The fan is chosen to have a flow characteristic such as to maintain the pressure differential across the fan approximately constant notwithstanding variations in the rate of air flow resulting from gaps in the stream. The belt is in two narrow, laterally spaced sections dimensioned to fit into the slots.

Abstract: A clamping device for thin flexible printing plates has a tensioning rail at the trailing wall of a wide longitudinal groove in the plate cylinder. The tensioning unit is mounted for axial and peripheral adjustment on a support of "L" cross-section having a first leg seated with respect to the bottom of the groove and a second leg presenting an upstanding reference surface interposed between the tensioning rail and the trailing wall of the groove. A set of tensioning springs recessed in the tensioning rail bear against the reference surface and apply peripheral tension to the plate. A spring detent latches the tensioning rail temporarily against the reference surface, overcoming the tensioning springs while the trailing edge of the plate is being gripped. The spring detent is mounted upon and movable with the support. Screws having a plurality of selectable holes anchor the support in a series of peripheral positions for accommodation of plates of different length.

Abstract: A fluid supply system for a lithographic printing press in which a fountain roller journalled in the frame of the press and driven at a slow speed is partially submerged so that a film of fluid is formed on its surface. A distributor roller is journalled in the frame parallel to the fountain roller and spaced therefrom to form a gap. A ductor roller movable broadwise in the gap is supported by a pair of arms which are, in turn, rigidly supported by a shaft journalled in the frame. A driving arm having a thrust rod connected thereto is rigidly secured to the shaft. The driving arm is coupled to a cam follower which engages a rotary cam so that upon rotation of the cam the shaft oscillates to swing the ductor roller back and forth for successive engagement of the fountain roller and the distributor roller to convey fluid therebetween. Opposed way surfaces are provided at the ends of the arms oriented generally perpendicular to the plane of the arms.

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.