Method and device for the optical detection of foreign fibers and other impurities in a longitudinally traveling yarn

US6744498B2 · kind B2 · utility

Assignee

• W. Schlafhorst AG & Co. · DE

Inventors

• Herbert Henze · Rheydt, DE
• Olav Birlem · Erkelenz, DE

Key dates

• Filing date: Feb 26, 2001
• Grant date: Jun 1, 2004
• Expiry date: Sep 30, 2021

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B65H2701/31
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Yarn impurities are detectable by a method and device wherein a first diameterdependent signal is obtained in a first measurement of a linearly traveling yarn, the intensity of the light for a second measurement is set as a function of the first signal to compensate for the effect of the yarn diameter on the light reflected by the yarn and then the second electrical signal can be directly evaluated for detecting yarn impurities. The invention improves the detection of impurities, for example in connection with spinning and bobbin winding machines.