Piezoelectric effect actuator in particular for use in textile machines

摘要

The invention relates generally to a actuator in the form of a bimorphous piezoelectric plate (13) consisting of two layers of piezoelectric ceramic material which are electrically insulated and between which a steel support sheet is located. Electrically polarising in a symmetrical manner the layers of piezoelectric ceramic material produces inflection of the plate (13), which is used to perform an actuating movement or an adjustment or an action. Suitably said plate operates as a lever and the layers of piezoelectric ceramic material thereof are polarised in a symmetrical manner by means of a voltage-modulated electric signal. According to a more specific aspect, the invention relates to the use of said actuator in a device for braking the weft yarns for weaving looms, in which the piezoelectric plate of the actuator acts on a weft yarn (F) running between said plate and a substantially rigid plate (11).