ANORDNING FOR STRECKNING AV GARN

摘要

A yarn tension control apparatus for tensioning a running length of yarn such as textile yarns or the like, wherein a plurality of tensioning devices form a controlled channel and are controlled by an electronic control circuit having a manually adjustable tension setting potentiometer for adjusting a circuit to provide output voltages to the tension devices of the channel adding selecting tension values to the yarn. The tensioning devices each comprise an electromagnet coil and core structure alongside which a pair of wear surface members in the form of plates or discs are supported in parallel vertical planes with the yarn running between and engaging the confronting surfaces of the wear surface members and the wear surface member located beyond the yarn plane from the coil and core structure being of magnetic material to be drawn toward the companion wear member by magnetic attractive forces to vary the tensioning of the yarn leaving the yarn tension devices. In the disc wear member embodiment, one of the discs is driven by a motor to effect a wiping action on the yarn. Degaussing circuit means are also disclosed for applying intermittent negative going pulses descending to a negative voltage level to the electromagnet coils during downward adjustment of the tension setting potentiometer to minimize residual magnetic effects.