Tappet and Cam Shedding Systems
topic
Tappet shedding uses hardened steel cams or tappets on the bottom shaft rotating at half loom speed to operate shaft levers that drive heald frames up and down in the pattern determined by tappet profile geometry, with positive and negative tappet systems ensuring controlled upward and downward shaft movement without reliance on spring return that could cause shaft timing errors at high machine speeds.
Role
Provides the mechanically simplest and most reliable shedding for plain weave and simple twill structures on up to 8 shafts, with tappet shedding being the standard mechanism on high-speed air-jet looms for commodity fabrics where the plain weave or simple twill structure requirement and high machine speeds favour the mechanically robust tappet over the greater complexity and weight of dobby mechanisms.