Improved sensor for controlling the supply of weft yarn or the like.

摘要

A sensor which measures the amount of thread (weft yarn) drawn off a temporary storage drum and fed to a device which picks same into a shed of warp yarns, utilizes the spiralling motion of the thread as it is drawn axially off the drum, to induce the thread to move around in close proximity of the periphery of a guide aperture once for each loop of the thread drawn off the drum and cut or reflect a light beam produced at or near the periphery of the aperture.