Man Roland Druckmaschinen Ag

Reinhard Zeller

Helmut Stuhlmiller

Hans E Mamberer

Eduard Hoffman

Otto Spang

The most uniform possible temperature variation along the circumference of a transfer cylinder in a rotary printing machine is achieved by arranging a highly thermally layer made of a material having a thermal conductivity significantly higher than steel under a rubber blanket on the transfer cylinder for distributing heat from the rubber blanket along the direction of the surface of the transfer cylinder. The highly conductive layer is arranged on a support of the rubber blanket.

Rotary printing machine with a plate cylinder, a transfer cylinder and an impression cylinder

A rotary offset printing machine having printing units each with a dampening unit and an inking unit with a metering device for setting an inking profile zone can reach the continuous printing state quickly and with little accumulation of rejects. First an inking profile is set on the metering device that is the inverse of the inking profile for continuous printing with the applicator rolls set off the printing plate and the machine operating at a first rotational speed. A defined quantity of ink is supplied to the inking unit, the inking profile for continuous printing then being set on the metering device. The rubber blankets are pre-dampened and, when a third rotational speed is reached, the print is set on. Finally, the printing machine is run up to a fourth speed for continuous printing when the separation of rejects is concluded.

Method of starting up a rotary offset printing machine

To distribute loading, and reduce wear, on filler inserts upon roll-off of printing machine cylinders formed with axial grooves, such as rubber blanket cylinders in offset printing machines, the filler insert is formed with an axially curved edge or surface (9, 10; 16, 18) which, either, is provided at the engagement surface of the respective filler insert element with the bottom wall (23, 24) of the groove (3, 4) or, alternatively, at the outer or top surface. The degree of curvature is such that, with respect to a flat surface tangent to the curved surface, a spacing or gap of, at the most, 0.2 mm, and preferably only about 0.1 mm, will result.

Printing cylinder groove filler

Roll-off shocks of cylinders, typically rubber blanket cylinders with respect to each other, are ameliorated or avoided by inserting a filler element into the groove which is located in the median third of the cylinder, but does not extend over the entire length thereof. The filler element is supported on the bottom of the groove, preferably over a damping or resilient element, and has a dimension which is equal to the outer circumference (44) of the bearer ring or the theoretical pitch circle (45) of a drive gear of the cylinder, with tolerance of not more than about .+-.0.05 mm. In order to insert the filler elements into the respcective grooves, the cover layers or, if necessary, also the substrate supports of rubber blankets, are removed in the region of the axial length of the filler element. Preferably, the filler elements are made of metal.

Printing cylinder and axial groove filler combination

To prevent printing of imperfect copy, by a printing machine having a lifter-type inker, which is caused by cyclically recurring rotary oscillations or vibrations, the braking torque introduced upon contact of a lifter roller (3) with the first milling and distribution roller (4) of the inker is prevented from propagating through the gearing drive of the respective inker rollers. To prevent such propagation, the first milling and distributing roller (4) is yieldingly driven at machine speed, for example by frictional drive, transmitted through an elastic surface (6) of a 'soft' roller in frictional drive engagement with the first milling and distributing roller (4) as well as with a positively driven subsequent milling and distributing roller (7), or a circumferentially resilient yielding coupling (13) is interposed between the drive shaft element (8) for the first milling and distibuting roller and a positive gear drive (10, 11, 12). Preferably, the inertia of the first milling and distributing roller is high with respect to that of the lifter roller (3), and is, for example, enhanced by a fly-wheel (4 a).

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Augsburg, Germany

Reinhard Zeller