Yarn feeder provided with a stationary drum and with a controlled, weft-braking device
AssigneeL.G.L. Electronics S.p.A.
InventorsGiorgio Bertocchi, Giovanni Pedrini, Pietro Zenoni
Life of this patent
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Abstract
A drum has a plurality of yarn loops wound thereon which are to be unwound upon request from a downstream machine. A weft-braking device provided with a braking member having a circular profile is biased against a delivery edge of the drum by driving elements. The yarn is adapted to run between the delivery edge and the braking member to receive a braking action by friction from them. The driving elements comprise at least one piezoelectric actuator which is deformable in response to a voltage applied thereto and has a movable operative end which is operatively connected to the braking member and a stationary operative end which is anchored to a stationary support.
Claims15
A yarn feeder comprising
- a drum having a plurality of yarn loops wound thereon which are to be unwound upon request from a downstream machine, and
- a weft-braking device provided with a braking member having a circular profile which is biased against a delivery edge of said drum by driving means,
- said yarn being adapted to run between said delivery edge and said braking member 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 which is deformable by bending in response to a voltage applied thereto and has a movable operative end which is operatively connected to said braking member 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.
Dependencies are inferred from the claim text.