Abstract: A belt drive for a machine for printing images on a flat printing material, having a continuous belt revolving during operation, includes a belt guide having stops for two protruding edges of the belt, the edges being oriented in a longitudinal direction of the belt and opposite one another in a transverse direction of the belt; and a machine for printing images on flat printing material having such a belt drive.

Abstract: A belt drive for a machine for processing flat printing materials includes an endless belt revolving during operation, a roller about which the belt is partially looped, a frame with respect to which the roller is adjustable between a working position, wherein the roller keeps the belt tensioned, and a position moved away from the working position, wherein the belt is untensioned, and a spring device for biasing the roller into the working position thereof. Also included are a double crank by which the roller is articulated with the frame, and a stop which, due to a change in position of the double crank from a position corresponding to the working position of the roller into a position corresponding to the moved-away position of the roller, is carried out to a given extent beyond a dead-center position of the double crank, prevents a change in position beyond the given extent; and a machine for processing flat printing materials, which includes the belt drive.

Abstract: Printing press cylinders are washed with a washcloth which is selectively wound forward and backward between a rotatable supply drum and a rotatable takeup drum. The washcloth is thereby cyclically pressed against a surface of a respective cylinder of the printing press in the washing operation and it is transported onward onto the takeup drum. The washing operation is controlled by detecting, with a sensor system, a transport distance of the washcloth and furnishing, with the sensor, a transport distance signal. The system is initialized by checking whether or not the insert is present and/or whether or not the insert carries enough fresh washcloth. This is done by winding the washcloth forward and back by a given distance. During the ongoing washing operation the transport speed of the washcloth is continously determined from the transport distance signal and comparing with a predetermined lower value and a predetermined upper value.