Patent ID: 6123281
Filing Date: 2000-09-26
Classification: D03D,G01D,H03K

Abstract:
A yarn feeder comprising a stationary storage drum, a yarn winding-on element which winds yarn onto said storage drum in windings, a yarn winding-on drive which drives said winding-on element, and at least one yarn sensor disposed a distance from said storage drum to detect said yarn on said storage drum, said yarn sensor having a sensor element which is directed toward a magnetic field of a flux conducting body wherein said flux conducting body is a magnetic or an electromagnetic material that generates said magnetic field, said flux conducting body being movable between positions close to said sensor element and remote from said sensor element depending on the presence or absence on or a movement of said yarn along said storage drum, said yarn sensor periodically emitting output signals during periodic detection times having a detection frequency pattern such that said yarn sensor generates control signals which control said yarn winding-on drive of said yarn feeder, said yarn sensor further comprising an interrupter which is connected to said yarn sensor to switch said yarn sensor on and off, said interrupter being clocked by a clock according to a predetermined clock frequency pattern which corresponds to said detection frequency pattern so that said yarn sensor is alternately switched on and off during continued operation of said yarn feeder, said interrupter being actuated according to said clock frequency pattern so that a respective one of said output signals exclusively is generated during one of said detection times after said yarn sensor has been first switched off and then on.