Yarn traverse apparatus

A yarn traverse apparatus comprising

• a bobbin on which a yarn is wound forming a yarn package;
• means for rotating said bobbin;
• setting means for setting upper and lower limit values of a crossing angle of said yarn, a traverse stroke of said yarn wound on said bobbin, a width of said yarn wound on said bobbin, and a ribbon occurrence region;
• bobbin rotational number detecting means for detecting the number of rotations of said bobbin on which said package is wound;
• winding-speed detecting means for detecting a winding speed of said yarn;
• package-diameter operation means for calculating a diameter of said package in accordance with said number of rotations of said bobbin detected by said bobbin rotational number detecting means and said winding speed of said yarn detected by said winding-speed detecting means;
• winding-ratio operation means for calculating a winding ratio in accordance with the number of turns of said yarn when a distance of two traverse strokes is divided by said yarn width and the number of turns of said yarn when one pitch corresponding to said upper limit value of said crossing angle is divided by said yarn width;
• traverse operation means for calculating the number of traverse strokes in accordance with said number of rotations of said bobbin and said winding ratio corresponding to said package diameter;
• and
• a traverse mechanism for traversing said yarn alternately in opposite directions parallel to an axis of rotation of said bobbin in accordance with an output of said traverse operation means so that said yarn is wound throughout said traverse stroke of said package;
• said winding-ratio operation means varying said winding ratio in steps so that said winding ratio is moved outside said ribbon occurrence region when said package diameter reaches a predetermined value between said upper and lower limit values of said crossing angle.