Patent ID: 8733246

Claim:
An offset printing apparatus comprising: a frame; a plurality of base members that are provided on the frame; guide rails, each of the guide rails being directly and fixedly attached to at least one of the plurality of base members; a plurality of guide blocks that are provided on the guide rails; a plate table for holding a plate that travels via one portion of the guide blocks among the plurality of guide blocks; a print target table for holding a print target that travels via another portion of the guide blocks among the plurality of guide blocks; and a blanket roll that is provided on the frame; wherein: transfer from the plate that is held on the plate table to the blanket roll, and retransfer from the blanket roll to the print target that is held on the print target table are performed by causing the blanket roll to successively make contact from above with the plate that is held on the plate table, and with the print target that is held on the print target table; a plurality of step portions for positioning are provided, each of the plurality of the step portions consisting of a vertical surface that is formed by a machining process so that the linearity increases and a horizontal surface at a respective mounting location of a respective guide rail on an upper surface portion of a respective base member; a side surface and a bottom surface of each of the guide rails are pressed against the vertical surface and the horizontal surface, respectively, of the respective step portion to be fixed to the respective step portion; and one of the plurality of the base members extends to a center portion in a width direction of the frame.