Patent ID: 8302532

Claim:
A printing machine comprising: an ink fountain member having a fountain-forming face; an ink fountain roller for applying ink to an outer peripheral surface through an ink channel between the ink fountain roller and the ink fountain member; a plurality of rollers for supplying the ink applied to the outer peripheral surface of the ink fountain roller to a printing portion; a strip of sheet placed over the ink fountain member so as to cover the fountain-forming face with the middle portion of the strip of sheet being in intimate contact with the fountain-forming face; a sheet moving device for moving the strip of sheet in the length direction; a pair of barrier plates attracted to the fountain-forming face from above the sheet and attracted to the outer peripheral surface of the ink fountain roller by a permanent magnet to form side walls of the ink fountain; a cleaning tank disposed close to the lower part of the ink fountain roller; a cleaning blade arranged in the cleaning tank; and a reciprocating device for switching the cleaning blade between a cleaning position being in pressing contact with the outer peripheral surface of the ink fountain roller and a stand-by position being away from the ink fountain roller; characterized in that the printing machine further comprises: a barrier plate replacing device for detaching the used barrier plate from the ink fountain member and the ink fountain roller and attaching the new barrier plate to the ink fountain member and the ink fountain roller, the barrier plate replacing device comprising: a fountain-member turning device for turning the ink fountain member around an axis parallel to the ink fountain roller, and positioning at a predetermined work position, a barrier plate stopper, arranged close to the outer peripheral surface of the ink fountain roller, for stopping the barrier plate rotated with the ink fountain roller away from the fountain-forming face by the turning of the ink fountain member from the work position, and turning the barrier plate in a direction away from the outer peripheral surface of the ink fountain roller, a moving body capable of moving above the ink fountain and being raised and lowered, and a barrier plate holding member disposed in the moving body to hold and release the barrier plate; a plurality of ink containers, accommodating different types of ink, and being stored in a predetermined container storage unit; an ink supply device for holding the desired ink container and supplying the ink to the ink fountain, and that a barrier plate attracting portion of a predetermined width having an entire periphery made of magnetic material is arranged at two or more areas in the axial direction on the outer periphery of the ink fountain roller, and a portion other than the barrier plate attracting portion is made of non-magnetic material.