Patent ID: 7905190

Claim:
A sewing machine comprising: a thread take-up; a thread take-up driving mechanism which drives the thread take-up; a sewing machine motor which drives the thread take-up driving mechanism; a thread cutting mechanism including a fixed cutting blade, a movable cutting blade both of which cut a needle thread, and a movable cutting blade driving mechanism which drives the movable cutting blade; a thread wiper which wipes the cut needle thread away over workpiece cloth to be sewn; a wiper driving mechanism which drives the thread wiper; a thread tension adjuster which adjusts a tension of the needle thread; a thread tension adjuster driving mechanism which drives the thread tension adjuster; and a control device coupled to: the sewing machine motor, the thread cutting mechanism, the wiper driving mechanism, and the thread tension adjuster driving mechanism, wherein the control device is configured to execute a needle thread cutting operation including: driving the movable cutting blade to a predetermined pivot location; driving the wiper driving mechanism for protruding the wiper by a predetermined stroke; driving the thread take-up driving mechanism to lower the thread take-up by a predetermined distance; driving the wiper driving mechanism to draw back the wiper by a predetermined amount corresponding to the lowering of the thread take-up; driving the movable cutting blade to a standby position; driving the thread tension adjusting mechanism to release the thread tension adjusting mechanism; and driving the thread take-up driving mechanism to move the thread take-up to an original uppermost position.