Inking unit

In an ink supply system of a keyless offset rotary printing press wherein excess dampening water from a water supply system invades the ink supply system, the ink supply system in which a roller and an ink fountain adapted to supply ink onto a peripheral surface of said roller are relatively arranged such that the distance between an internal bottom surface of said ink fountain and the peripheral surface of said roller is decreased gradually to a downstream end from an upstream end of said ink fountain in the direction of rotation of said roller, an inking unit comprising

• an ink circulating assembly including said ink fountain provided in said ink reservoir, ink outlet means for introducing the ink into said ink fountain, an ink reservoir having an open top and surrounding said ink fountain from beneath the ink fountain, a screw conveyor arranged along the longitudinal direction within said ink reservoir for conveying the ink and mixing said excess dampening water therewith and diffusing said excess dampening water thereinto, and a pipe connecting said ink reservoir and said ink outlet means;
• a platform on which said ink circulating assembly is mounted, and
• means for moving said platform, including a lifter for vertically moving said platform, and casters for horizontally moving said platform, in order for use both as adjustment of a position of said ink fountain in relation to said roller and as removal of said ink circulating assembly to repair and/or to change one to another.