| 摘要 |
PURPOSE:To contrive to print in two colors by a small-type serial printer with a simple mechanism and to increase the kind of signs to be printed, by a method wherein a rack body provided with the first rack and the second rack is rotated selectively, and two carriages are separately traveled. CONSTITUTION:In the rack body 20, the first rack 20a engaged with the first carriage 22 and the second rack 20b engaged with the second carriage 25 are provided at angular positions shifted from each other by 180 deg.. Either one of the racks 20a, 20b is selectively engaged with a screw body of the corresponding carriage 22, 25 by selecting the rotational number of a type wheel shaft 1 in the starting period of printing one line. Thereafter, in the next rotation of type wheels 24, 28 and 27, an electromagnet 8 is operated on the basis of a printing command, an operating lever 9 is released from the second clutch 7 and is engaged with a ratchet 3, resulting in that the shaft 1 is stopped. In this case, the rotation of a motor 10 is transmitted to a hammer-driving shaft through gears 5, 14, and a hammer body 16 is rotated. |
