Electromagnetic yarn stopping device for premeasuring weft feeders of air-jet looms

摘要

A device for stopping the yarn for premeasuring weft feeders of air-jet looms, of the electromagnetic type, comprising a stop finger which can move radially with respect to a drum of a weft feeder and is adapted to laterally engage a yarn in order to block its unwinding from the drum. The device further comprises at least one permanent magnet which is constituted by at least one cylindrical body in which the polar axis is orientated radially. The cylindrical body is associated with a stem which is provided with the stop finger and can move in a linear fashion inside a cylindrical surface on which at least one coil is wound, an excitation current flowing through the coil. The axis of the cylindrical surface, which coincides with the axis of the movable stem, is perpendicular to the polar axis of the cylindrical body of the permanent magnet.