Patent ID: 6760102
Filing Date: 2004-07-06
Classification: B65H,G01N

Abstract:
A process for continuous detection and localization of yarn defects in a yarn sheer which is traveling in a plane and which is scanned by light beams for yarn defects such as protruding filaments, broken filaments, fuzzballs, stripbacks, ringers and the like, each light beam interruption triggered by such a yarn defect triggering a detector signal, which comprises the yarn sheet passing through a measuring arrangement which consists of light barriers made up of light sources and detectors being arranged relative to each other in a V-shape and also evaluating means, the light beams of the light barriers extending parallel to the yarn sheet plane, at constant speed and the travel distances of the individual ends from one light barrier to the adjacent light barrier differing in length, and wherein the detector signal triggered by a defective end within the yarn sheet on passing through the first light barrier is compared with the detector signals of a second and, where appropriate, third and forth light barrier and examined for agreement with or deviations from the travel times of the coincidence conditions concerning the yarn defect to ensure that the evaluated detector signals come from the defect of the same individual end.