Improvements in or relating to lithographic printing.

摘要

An ink duct for applying ink to the surface of a roller (8) mounted for rotation about its cylindrical axis (9) comprises a chamber having an open side capable of being substantially closed by the roller surface (10) and bounded by an axially extending doctor blade (42) having an edge protruding towards the open side for contacting the roller surface (10), an axially extending sealing member (41) having an edge protruding towards the open side, and end seals (48) linking the blade (42) and the sealing member (41) at their ends and having edges protruding towards the open side for sealing engagement with the roller surface (10). The chamber includes an axially extending projection (44) located between the blade (42) and the sealing member (41) and having an edge protruding towards the open side to divide the chamber into first and second zones (45-46) whilst allowing ink to flow past the edge from the first zone (45) to the second zone (46). A first axially extending slot (62) is provided in the first zone (45) for the introduction of ink into the first zone (45) and an outlet (64) is provided in the second zone (46) for egress of ink from the second zone (46). A lithographic printing press includes two of said ink ducts pivotally mounted so that one or the other may be engaged with the surface of the roller (10).