Typewriter roller operation control - has driving elements and drive crank designed as a reversible driving pin crank

摘要

The arrangement facilitates driving movement of rollers in one or the opposite sense during the same time period of a working cycle. The driving members and the drive crank a are designed as a reversible driving pin crank, the members of which are basically in an outstretched position, when the mechanism is in a basic position. The driving pin crank is fitted with control elements which act on the crank in such a way as to permit an optional swing-out motion in both operating directions. The drive crank and the drive elements are parts of any articulated quadrangle, fitted with a driving crank, which performs a complete turn for each operation stroke, having a crank arm shorter than the drive crank.