Heidelberger Druckmaschinen Ag

Steve Cormier

Kenneth D Fraser

Anton Rodi

Peter Taylor

Gerhard Bartscher

Uwe Angst

Carsten Schoenfeld

A cylinder (2) for a printing machine, particularly a developing cylinder in an electrographic printing machine, having a rigid, elongated shaft body (10) and a rigid hollow body (11) whose exterior forms the covering and the top and bottom surfaces of the cylinder. In order that, during operation under constant conditions, the cylinder can roll properly against another rigid cylinder of the printing machine, flat sides (12,13) of the hollow body (11) which form the top and bottom surfaces of the cylinder, have centrical bore holes that are larger than the diameter of the shaft body (10) in the area of the flat sides. Located in the space between the shaft body and the flat sides of the hollow body is an elastic material (14,15) which joins the flat sides of the hollow body to the shaft body. Inside the hollow body, in the center between the flat sides of the hollow body one or a plurality of braces (16) are arranged which extend transversely to the figure axis of the shaft body, and which firmly join the hollow cylindrical covering of the hollow body to the shaft body, so that the figure axis of the hollow body and the figure axis of the shaft body coincide in a normal state, and intersect at a small angle under the influence of outer forces.

Cylinder for a printing machine

A device and a method for developing an electrostatic latent image, which is located on a movable image carrier (1), using a non-conductive single-component toner. The device includes a toner feed device (3), in order to transport toner particles (5) from a toner reservoir (4) and charge them electrically, a rotationally mounted developing roller (2) to receive the charged toner particles from the toner feed device and to transport the toner particles which it holds into a gap between the developing roller and the image carrier, and a rotationally mounted doctor roller (6), which is arranged in the path of the toner particles from the toner feed device to the developing roller, to produce a uniform toner layer with a defined thickness on the developing roller. The surface of the developing roller (2) and the surface of the doctor roller (6) are separated from one another by a gap which is wider than the average diameter of the toner particles (5). In this manner, electrographic printing with high quality and at high speed is made possible.

Single-component developing station

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Leominster, ME, United States of America

Steve Cormier