Man Roland Druckmaschinen Ag

Rudolf Raab

Peter Hummel

Robert Ortner

Paul Abendroth

Manfred Herold

Harry Brandes

An offset printing machine having a plate cylinder which carries a printing form and which is operatively connected to an inking unit and a dampening unit is provided. The dampening unit includes a dampening applicator roller which is mounted in contacting relation with the dampening applicator roller. The dampening applicator roller also includes at least one auxiliary roller which is mounted in contacting relation with the dampening applicator roller downstream or after the contact point between the dampening applicator roller and the plate cylinder. The auxiliary roller has a surface with a coating of non-stick material which blocks the transfer of ink and dampening medium to the surface of the auxiliary roller and is axially movable relative to the dampening applicator roller and selectively rotatable at circumferential speeds substantially equal to or different from the circumferential speed of the dampening applicator roller.

Dampening unit for an offset printing machine

An air cushion drum for a sheet-fed printing press is formed with an internal body and an outer casing defining a cavity inside the drum through which air streams are supplied to issue from orifices in the drum casing and force the sheets away therefrom. To reduce airflow noise a sound-absorbent layer which has radial ducts is disposed in the cavity and forms therein an air-permeable partition which is equidistant from the drum casing. In the preferred embodiment, the sound-absorbent layer is supported by a lattice formed with droplet shaped members which further reduce air flow resistance and the sound-absorbent layer which may be formed of felt or foam is supported on the lattice by an outer stabilizing layer of plastic material.

Air cushion drum or sheet-fed printing presses

A resilient sheet gripper for a sheet-fed rotary printing press having a gripper shaft to which is secured a pivoting clamping member in resilient relationship with a pivoted gripper finger having adjustable biasing provided by compression spring means, is provided including an adjusting screw mounted in a stop strip, an abutment for contacting the screw mounted for movement around the gripper shaft, a guide pin fixed to the abutment and disposed in a biased conical sleeve in the gripper finger so that the finger can move perpendicular to a gripper support upon closure of the gripper finger.

Growing community of inventors

Hanau, Germany

Rudolf Raab