Abstract: Constant tension in the thermal printing ribbon is maintained in a loading drum placed after the thermal print head that directs the ribbon by means of a planetary pivotable support lever arm to define a loop, thereby maintaining constant tension throughout the printing stage to ensure operational quality. The printing method includes threading the thermal printing ribbon between the pivotable support lever arm and the cylindrical drum, and the mechanism retains the printing ribbon against the loading drum by a biasing force on the lever arm, the lever arm being kept in biasing mode during the printing operation.

Abstract: Applicable to machines having a moving carriage (4) that can move transversally with respect to the continuous band to be printed and that includes a thermal printing head (9) by which passes a thermal ribbon, from a cassette of origin (5) to a destination cassette (10), which pulls said ribbon (7), its characteristics centred on the fact that the drive motor for said ribbon (7) instead of being established on the moving carriage (4) is established on the fixed plate (3) along which the aforementioned carriage may travel, for which purpose said motor acts directly or indirectly on a roller (12) mounted on the fixed plate (3), aided by a return roller (14) to establish a transmission belt (14) which bends in its path due to a pair of auxiliary rollers (16–16?) mounted free to revolve about the carriage (4), by which bend the belt (13) is connected to a drive roller (15) that is also mounted on the carriage (4), which transmits the motion to the pulling cassette (10) by a transmission belt (20) and by a clutch