Method and apparatus for forming a yarn reserve on a cross-wound bobbin

摘要

A method for forming a yarn reserve on an end surface of a cross-wound bobbin or cheese disposed on a bobbin tube includes predetermining a length of yarn for a yarn reserve. The yarn is unwound to the predetermined length from a cheese while temporarily storing the yarn in a reservoir. The presence of the yarn in the reservoir is detected with a sensor. The unwinding of the yarn is stopped and the rotational direction of the cheese is reversed to the given winding direction after attaining the predetermined length of the yarn. The yarn is then wound onto the one end of the bobbin tube while continuously holding the yarn taut with a restraining force of the reservoir. An apparatus for changing cheeses on a machine that produces cheeses and for forming a yarn reserve on an end surface of a cheese disposed on a bobbin tube includes a drive mechanism for unwinding a predetermined length of a yarn from a cheese. A reservoir receives and stores the yarn from the cheese. A yarn guide positions the yarn in the vicinity of and deposits the yarn on one of the ends of the bobbin tube. At least one sensor is disposed in at least one of the yarn guide and the reservoir for detecting the received yarn. A control device is connected to the at least one sensor for controlling the drive mechanism.