Abstract: This invention relates to a printing press including an impression cylinder and a plurality of printing units which include drive gears and plate cylinders which are movable into and out of engagement with the impression cylinder. The press also includes a driven central gear which is coaxial to the impression cylinder and in mesh with all plate cylinder drive gears. The plate cylinders are permitted to have a plate length which is not exactly equal to an integral multiple of the tooth pitch of the plate cylinder gears so that the peripheral length of the plate cylinder is not an integral multiple of the tooth pitch of the central gear. The central gear is operatively connected by a gear train to drive a gear that is secured to the stub shaft of the impression cylinder. The gear train includes a differential gear train which has an input member that is adapted to be driven by an infinitely controllable transmission or by a stepping motor or the like.

Abstract: An apparatus for stacking double bags, which have been severed by hot-wire welding from a tubular web of plastic and have opening-defining edges adjacent to their center line, includes a wicketer having a horizontal shaft and pairs of juxtaposed spokelike radial feeding arms which are axially spaced apart and secured to the shaft and are provided with means for retaining the double bags. Stacking pallets provided with upstanding stacking pins are slidably movable between the feeding arms, by which the double bags are deposited on the pallets, e.g., on needles provided on the pallets.

Abstract: To make plastic carrying bags or sacks, sections are cut or are severed by hot wire welding from a gusseted tubular film by a formation of transverse seam welds and transverse severing cuts or by hot wire-welded transverse seam welds. At least in their bottom portion the sections are provided with corner seam welds, which are separately formed in the two folds and which diverge obliquely from the outer fold lines toward the top and/or bottom seam weld and terminate short of the inner fold line and merge into the latter. To prevent in the making of the carrying bags an elongation of the intermediate portion of the tubular film, the latter is initially formed with corner seam welds only in one fold of each of the two gussets before the transverse seam welds and transverse severing cuts or hot wire-welded transverse seam welds are formed. When said corner seam welds have cooled, congruent corner seam welds are formed in the respective other folds.