ALIMENTATORE DI FILATO A TAMBURO FISSO CON DISPOSITIVO FRENA-TRAMA CONTROLLATO

摘要

A drum (12) has a plurality of yarn loops (Y) wound thereon which are to be unwound upon request from a downstream machine. A weft-braking device (46) provided with a braking member (26) having a circular profile is biased against a delivery edge (12a) of the drum by driving means. The yarn (Y) is adapted to run between the delivery edge (12a) and the braking member (26) to receive a braking action by fricton from them. The driving means comprise at least one piezoelectric actuator (76) which is deformable in response to a voltage applied thereto and has a movable operative end (76a) which is operatively connected to the braking member (26) and a stationary operative end (76b) which is anchored to a stationary support (52).