Abstract: An apparatus for displacing bearing blocks which are mounted on carriages and which support shafts to be displaceable on a common carriage guideway, preferably for the displacement of bearing blocks of plate cylinders and inking rollers of an inking unit in carriage guideways of the inking unit brackets of a multicolour rotary printing press, with two lead screw drives driven by two electric motors, preferably stepper motors. Each bearing block is provided with a nut into which there is respectively screwed one lead screw assigned to each of the bearing blocks. Each of the two lead screws is provided with one lead screw drive each, fixed to the frame at the end zones of the carriage guideway lying opposite each other.