Thread feeding mechanism - for sewing machines with two non-contacting-rollers for min. hold-back forces

摘要

Sewing cotton or band is supplied to a sewing machine by not contacting rollers which the thread encricles in an S-curve with a large angle of contact. Both rollers have a variable centre distance and are driven by the main sewing machine shaft or by a separate motor. Pref. the thread or band is fed by the transporting system which has two rollers driven by gear or friction wheels from a disc or from a separate motor. No transport is effected if the force F1 is 0, this permits hold-back forces F1 of under 5 x 10 exp.-2 N, if a disturbing force of F2 is 1 N should occur. ADVANTAGE - This minimises the hold-back and the thread brak