Sewing machine with the yarn tension control function and method for controlling a yarn tension for this purpose a direction

摘要

PROBLEM TO BE SOLVED: To improve the smoothness by reducing the stress of a worker in attaching/detaching a thread cassette to/from a cassette mounting part and to securely and successfully control the thread tension of a thread led out of the thread cassette.;SOLUTION: In mounting the thread cassette on the cassette mounting part, when it is determined that the thread cassette has been mounted on the cassette mounting part (S3; Yes), the driving of a pulse motor is started 30 msec after that, and a cam member is rotated to a prescribed position. At the time, a needle bar is moved from a position where the thread cassette can be inserted (that is a position of a left base line) to a regular needle swing position (for example, a neutral position where the needle bar is perpendicular) (S11), and a pair of thread tension trays are closed (S12).;COPYRIGHT: (C)2004,JPO