| 摘要 |
PURPOSE:To simplify the control and the mechanical structure of a printing apparatus, by a method wherein the shift operation of each ribbon in printing/ erasion is carried out by the same plunger and a cam mechanism is added to carry out the selective shift of each ribbon. CONSTITUTION:The shift operations of a printing ribbon 1 and an erasing ribbon 8 are carried out by an electromagnetic plunger 13, a cam 200 and a latch mechanism 210. The cam 200 comprises integrally molded cams 201-203 and is pivotably supported by the shaft 204 of the main body of a typewriter while rotated by the plunger 13 through the latch mechanism 210. By this rotation, the protrusion 92 provided to the lower part of an arm 9 is pushed up while the arm 9 and a printing ribbon cassette 5 are pushed up to carry out ribbon shift. |
