| 摘要 |
PURPOSE:To enable relative positions of needles of a plurality of dot printing heads to be determined easily and accurately, by providing a guide frame with positioning projections and providing a needle guide with positioning holes to be engaged with the projections. CONSTITUTION:A tip part of the guide frame 7 is provided with a slit 14, the positioning projections 15 located at both ends of the slit 14, and an annular groove 16 and a recessed part 17 which surround the slit 14. The recessed part 17 is provided with projected parts 18 on the inside surface thereof, the distance between each opposed pair of the projected parts 18 is so set that the needle guide 19 is fitted thereto with a play. Fitting screws 13 are untightened, a thickness gage with a predetermined thickness is inserted between the tip of each of the guide frames 7 and a platen 2, and the screws 13 are tightened while pressing the dot printing heads 5, 6 against the platen 2 side and the reference surface 11 side. Accordingly, the gap between each needle 20 and the platen 2 is adjusted, and the fitting spacing of the heads 5, 6 and the rectangularity of the centers of the heads 5, 6 to the platen 2 are determined by the reference surfaces 11. |
