An offset printing device is provided for a rotary printing machine having a plate cylinder carrying a dry flatbed printing plate, the printing device having an improved inking unit which reduces the occurrence and effect of contaminants. In the inking unit, at least one ink application roller, which is frictionally engaged against the plate cylinder during printing, is drivable by at least one positively driven inking roller at a peripheral speed which is different from the peripheral speed of ...

An automatic control apparatus in a printing press includes plate replacing units, an ink presetting portion, and a test printing control unit and a CPU. Each plate replacing unit mounts a printing plate on a circumferential surface of a plate cylinder. The ink presetting portion forms, in a roller group of an ink supply unit, an ink film thickness distribution corresponding to an image of the printing plate which is to be mounted on the plate cylinder. The test printing control unit and the CPU...

An ink fountain for rotary offset printing presses with an ink dosing device which includes of a plurality of zone-width dosing elements located next to one another in close proximity. The dosing elements have support and dosing areas, and the support areas are in constant direct or indirect contact under spring pressure with an ink fountain roller. The dosing areas can be adjusted to different ink gap thicknesses by rotating the dosing elements. The hydrodynamic forces or the spring pressure on...

A printing apparatus for printing a printing-paper is provided with two plate cylinders each holding a plate, two blanket cylinders coming into contact with the plate cylinders respectively and a single impression cylinder coming into contact with these blanket cylinders. Each plate has two printing areas. The two plate cylinders and the two blanket cylinders have the same diameter, which is twice that of the impression cylinder. The impression cylinder is in contact with a feed cylinder and a r...

In a printing method usable for color printing as well as printing in black and white, a printing form is utilized, comprising a multiple of separate channels each terminating in an orifice in a surface, used as printing surface, which orifice is arranged to form a neutral screen pattern, i.e. a screen pattern which has no connection to the figuration of the intended prints. The printing form for printing by charging the channels with printing ink columns for each channel selected to correspond ...

A hand printing stamp for transferring ink from an ink pad to a sheet of paper or the like, including movable portions on the printing face of the stamp so that different images may be reproduced from one stamp. In the embodiment disclosed, the movable parts include arms, legs and the head of a figure so that the figure may be reproduced in a plurality of articulated positions.

A dampener for lithographic printing presses is disclosed wherein means are provided for continuously generating a spray or mist of dampening fluid having optimum particle size and density characteristics and the volume of spray which is permitted to reach the plate cylinder is metered by a series of baffles that extend over the full length of the plate cylinder. The baffles are all connected for movement in unison with a common control member that is responsive automatically to changes in press...

A vibrator mechanism for axially reciprocating the ink drums of a rotary printing press inking mechanism in predetermined phase relationship consists of coacting inner and outer eccentrics that are telescoped over each other and over a common drive shaft. The inner eccentric is releasably connected to the drive shaft so that it can be adjusted angularly about the drive shaft relative to the outer eccentric from a remote, conveniently accessible position to thereby vary the amplitude of the recip...

An intaglio printing process utilizing a printing plate consisting of a precise engraving element which is adapted from a gravure printing plate. This printing plate is applied on the plate cylinder and printed with very stiff and viscous ink as used for engraving intaglio printing. Ink of various colors may be applied separately on different portions of the gravure plate surface by rollers. After inking, surplus ink can be wiped of by a wiping roller. Printing paper is introduced between the pl...

A stencil screen printing press especially suitable for web stock, employing a stencil frame that rocks back and forth over a curved bed in a controlled relation to retractable web register means and to web directional control and advancing means.