GB501185A - Improvements in or relating to ink-ribbon mechanism - Google Patents

Abstract

501,185. Ink-ribbon mechanism. INTERNATIONAL BUSINESS MACHINES CORPORATION. June 10, 1938, No. 17278. Convention date, July 24, 1937. [Class 100 (iv)] Mechanism for feeding a duplicating-ribbon along the printing line of a typewriter is mounted independently of the carriage and is driven from the carriage by means of a flexible connection. In the apparatus shown in Figs. 1 and 3, a casting 16 secured to the rear of the typewriter-base 10 supports a take-up spool 36 and a supply spool 17 for a duplicating- ribbon 18, the take-up spool being coupled by means of a spring-belt 41 to the continuously rotating' power-roller PR of'the typewriter. The ribbon passes over grooved rollers 19, 33 on the casting and is directed along the platen 15 by means of pairs of turnerguides 21, 26 secured to a bail 22 which is mounted on pivots 28 on rearward extensions 29 of the platen-carriage. Each guide is arranged to turn the ribbon through a rightangle and consists of a strip which is bent to provide a curved intermediate part and is provided with keepers 21a or 26b for the ribbon. Springs are provided for holding the bail in an upper sheet-insertion position, or in a depressed position in which the ribbon is arranged along the printing line, these positions being determined by stops 29a, 29c. A pressure-roller 48, mounted on a spring-urged bell-crank 45, co-operates with the feed-roller 33. A paper-bail 63b, pivoted on the carriage, is raised by the bail 22. A tape 55, passing round a grooved pulley 56 and a groove in the roller 33, is connected at the ends to the arms 22 and is also connected to one of the arms by a spring 58. During letter-spacing movements of the carriage, the roller 33 rotates step-by-step by means of the tape, and the ribbon is fed in step with the carriage without moving relatively thereto, and is taken up by the spool 36. When the carriage is returned, a pawl locks the roller 33, the tape 55 slips idly, and the carriage moves relatively to the ribbon to bring a fresh length thereof into the printing line.