| 摘要 |
PURPOSE:To make it possible to prevent the lowering of printing quality caused by temp. change, in a wire dot printer, by interposing a spacer having proper coefficient of thermal expansion between the stopper of a printing pin and a stopper plate holding and fixing plate. CONSTITUTION:The stopper 14 of a printing head pin 8 functions as a damper and, at the same time, determines the interval (d) of an armature 5 and the parallel rod 202 of a yoke 2. This stopper 14 is supported by a stopper plate 13 held to a fixed plate 12 through a spacer 15 and the interval (d) is changed corresponding to the thermal expansion of the spacer 15 caused by temp. change. Because this interval (d) controls the attraction force and the stroke between the parallel rod 202 and the armature 5, the following property of the printing head pin 8 is enhanced at a high temp. while delayed at a low temp. to perform compensation and the following property of the whole printing head pins is kept constant to make it possible to maintain printing quality regardless of temp. change. |
