| 摘要 |
PURPOSE:To improve the quality of printing by preventing a printing hammer and it supporting step from twisting, by providing plural printing hammers in inclined positions so that the hammer edges cross at right angles with helical edges. CONSTITUTION:When driving current is made to pass through a moving coil 5, the coil 5 receives a force heading for a rotary drum 1, a printing hammer 4 which holds this as a continuous body is moved toward the drum 1, and a hammer edge 3 strikes a helical edge 2. In this case, the hammer edge 3 and the helical edge 2 are to have such a relationship as to cross each other rectangularly at any striking position. And therefore, the hammer edge 3 only receives the force heading for the lengthwise direction while it is in contact with the helical edge 2. Further, sinc the hammers 4 are arranged in inclined positions, their supporting steps are aligned with the hammers 4, and therefore, it is possible to prevent the hammers 4 from being twisted, the strinking pressure from weakening and the printing ghost from occurrence. |
