PRINTING MACHINE ADAPTED FOR REDUCTION OF ITS OPERATING NOISE LEVEL

摘要

A printing assembly which is adapted for printing on a print medium in a form of a sheet or tape includes a printing cylinder on which is wound and urged the print medium during a printing operation. A printing device prints on the print medium and urges it against the printing cylinder. An advancing device upstream of the printing device serves to advance the print medium and a tensioning device downstream of the printing devices tightens the print medium against the printing cylinder. The tensioning device includes two contra-rotating rollers having substantially smooth outer surfaces in contact from opposite sides of the print medium which allow sliding at the contacting surfaces and which provide for tensioning of the print medium on the print cylinder. The rollers are of the same diameter and are both motorpowered and driven at the same rotational velocity, which rotational velocity is greater than the advance velocity of the advancing device. The tensioning device also includes a mechanism for pulling the rollers elastically towards each other with forces which are substantially constant and identical.