Abstract: A printing unit for a flexographic printing machine having an individual or sole impression cylinder (10) comprises a plate cylinder (9) and an inking cylinder (11) slidably mounted by means fo supports (16, 25) on a bed (2). In order to facilitate the displacement and the positioning of the cylinders (9, 10, 11) with respect to each other, it is provided for the supports (16 , 25), arranged on one and the same side of the longitudinal central plane of the continuous material to be printed, to be mounted on one and the same guide shaft (17) which is integral with the bed (2) and to ensure their displacement with the aid of common control means (36) for rapid approach and disengagement in order to obtain the engagement and the disengagement of the cylinders (9, 10, 11) with respect to one another.

Abstract: A gusseted tubing former designed to be incorporated in a bag manufacturing line, preferably for manufacturing paper bags from a continuous paper web. The web is formed around the periphery of the former to produce a continuous tubing. As the tubing moves along the former in the manufacturing line, it emerges in the form of a flat tubing which includes two inwardly directed gussets, or folds. To prevent transverse stresses on the web during the formation of the gussets, the former includes edges which longitudinally extend in a direction which follows the folding lines of the gussets of the tubing as the tubing is progressively flattened from an upstream end to a downstream end of the former.