Patent ID: 9303338
Filing Date: 2016-04-05
CPC Classification: B65H,D03D

Claim Text:
1. A weft-braking device for installation on a yarn feeder provided with a stationary drum having a plurality of yarn loops wound thereon which are to be unwound upon request from a downstream machine, comprising: a first annular plate coaxially supported in front of a delivery end of the drum, and a second annular plate which is coaxially biased against said first annular plate by driving means, said yarn being adapted to run between said annular plates to receive a braking action by friction from them, wherein said driving means comprise at least one piezoelectric actuator which is a flat, piezoelectric bending actuator deformable by bending in response to a voltage applied thereto and has a movable operative end which is operatively connected to said second annular plate and a stationary operative end which is anchored to a stationary support, wherein said piezoelectric actuator has an annular profile and is a multilayer, monolithical-type actuator formed by a plurality of layers made of a piezoelectric material alternated to layers of a conductive material, said layers being bonded to one another by sintering.