(57) @ A printing mechanism, especially an over-printing mechanism for fitment onto packaging machinery for example, the printing mechanism comprising a printing head which is movable by a pneumatic cylinder and a connecting linkage to-and-fro through an arcuate path between a printing position and a parked position and rectilinearly at the printing position. The printing mechanism also includes an ink roller mounted in a pivotal cradle which is movable either by the same or another pneumatic cylinder either towards the printing head on arcuate movement of the latter towards the printing position to permit type carried by the printing head to wipe across the ink roller or clear of the printing head during its arcuate movement away from the printing position and then back to permit the printing head to wipe across same during its return arcuate movement.
With the single pneumatic cylinder arrangement the cradle movement is via a cam and linkage arrangement.