Abstract: Comprises an origin cylinder (1) of heat-sensitive ink ribbon (2), a rewinding cylinder (5), traction means and at least one marking header. It prevents an unused segment of ribbon being left between markings. It is characterised by a moving support (6) in which is guided the ribbon (2) such that the ribbon follows an additional path (16). It comprises braking means (10, 11, 12, 14) for the origin cylinder (1) such that when the ribbon (2) is tractioned and as the origin cylinder is braked, the support (6) is forced to move against the action of an elastic element (13), reducing the additional path (16) such that after a marking (a-b) the ribbon moves back, and with it the support (6), due to the action of the elastic element (13) so that the next marking (b-d) is made immediately after the first.