A method for very accurately measuring the length and for the tension of a filament during unwinding at very high speeds and with abrupt accelerations

摘要

986, 539. Measuring length of filaments. SOBREVIN SOC. DE BREVETS INDUSTRIELS ETABLISSEMENT. Oct. 24, 1962 [Oct. 31, 1961; Aug. 11, 1962], No. 40310/62. Heading G1M. A device for measuring the length and adjusting the tension of a filament comprises a pulley 1 rotated at a tangential speed approximating to that at which filament 3 is moving. The filament is supplied tangentially to the pulley and leaves it, at 3SP111/SP, in an axial direction, passing under a resilient member 4. The device adjusts the tension of the filament and the revolutions of the pulley, counted by member 2, are a measure of the length of the filament. A photo-electric cell 6, or a photo-transister, receiving light through a transparent part of pulley 1 from a source 5 is provided to retard the pulley if the stock 3SP11/SP of filament thereon exceeds a desired limit or to accelerate the pulley if the stock 3SP11/SP is low.