Dr. Ing. Rudolf Hell Gmbh

Walter Baar

Jurgen Dolves

Walter Muecke

Herbert Koehler

The invention provides an improvement for an apparatus which produces engraved printing forms via an electron beam device which is located in a vacuum chamber having an open side facing a peripheral surface of a printing form cylinder and defining therewith an air gap, and an arrangement for effecting relative movement of the vacuum chamber and printing form cylinder while maintaining the air gap. The inventive improvement comprises an annular member having an outer circumferential surface of a diameter corresponding to the outer diameter of the printing form cylinder, and cooperating annular bevelled contact faces provided on respective axial ends of the annular member and printing form cylinder so that, when the contact faces are coaxial and urged into abutment with one another, the outer circumferential surface constitutes an extension of the peripheral surface of the printing form cylinder.

Matrix engraving by electron beams

A method for the production of a printing form by the scanning point-by-point and line-by-line of an image pattern along successive cylindrical peripheral image lines and engraving cavities along corresponding cylindrical peripheral engraving lines, features the steps of generating scanning image signals from the image pattern from along one of the cylindrical peripheral image lines, reading the image signals into a storage device, reading the stored image signals out of the storage device and coupling the read-out image signals to an engraving device. Then, the engraving with the engraving device is carried out along a cylindrical peripheral engraving line corresponding to the one image line in response to the read-out image signals. The engraving device is moved to a succeeding cylindrical peripheral engraving line, the read-out of said image signals and the engraving of cavities are inhibited at least during the time said engraving device is being moved to the succeeding engraving line, continuing the read-out and engraving of said succeeding engraving line at the stored image signals or cavities marking the end of the moving of said engraving device and in that, when the end of the engraving line is reached, the first portion of it, which was previously omitted, is engraved retrospectively and the next movement of the engraving device to the succeeding engraving line takes place.

Method for the production of printing forms

An engraving device having a rotary system including a shaft supported in a bearing for rotation through very small angles, means to oscillate the shaft, an engraving needle carried on a lever attached to one end of the shaft adjacent the bearing and a dampening device characterized by the dampening device being arranged between the bearing and lever and the dampening device applying symmetrical forces on the shaft so that the dampening forces do not create bending forces on the shaft. Preferably the dampening device is located closely adjacent to the lever. A preferred embodiment of the dampening device uses a stationary support having a surface surrounding the shaft and either a closed ring of fluoro-plastic dampening material which is connected to the shaft and surface or two or more fluoro-plastic elements which are circumferentially spaced between the shaft and the surface and connected thereto. In another embodiment of the dampening device either an annular ring is attached to the shaft and is received in an annular container of grease or a pair of circumferentially spaced wings are attached to the shaft and extend in to symmetrically arranged containers of grease.

Growing community of inventors

Kiel, Germany

Walter Baar