| 摘要 |
PURPOSE:To increase the precision of a printing hammer magnet by a method wherein the portions of a joint jig which contact in many times with a plate for forming a core and a member for forming the printing hammer magnet are formed of high-hardness material in the formation of said magnet. CONSTITUTION:As to a joint jig 11, a reference surface 12 contacting with the base portion of a core forming plate 4, a reference surface 13 contacting with wht base portion of a printing hammer magnet forming member 2, a reference surface 14 contacting with a reference rod 9, and a reference surface 15 contacting with a reference rod 10, are formed by embedding a member of quenched steel, for instance, having a higher hardness than an aluminum material forming the jig 11, 1-2mm. deep in said jig. By this method, the reference surfaces of the jig are prevented from being worn away even in employment of many times, and thus a printing hammer magnet of high precision can be obtained. |
