| 摘要 |
PROBLEM TO BE SOLVED: To give a suitable upper thread tension regardless of a cloth feed direction. SOLUTION: A feed switch detection sensor 46 for detecting that the cloth feed direction is switched from a normal direction to a reverse direction by the operation of a reverse feed lever 45 is provided. When switching of the feed direction to the reverse direction is detected from a detection signal of this feed switch detection sensor 46 or a touch back switch 47, the generation of hitch stitch when switched to reverse feed is prevented by a control part 100 automatically weakly adjusting the upper thread tension by a thread tension solenoid 53 than the time of normal feed. Also, when a thread cut signal by backward operation of an operation pedal 60 is detected, the residual end length of an upper thread T remaining on the cloth side after cutting can be shortened by the control part 100 automatically strongly adjusting the upper thread tension by the thread tension solenoid 53 than the time of reverse feed. Accordingly, a beautiful thread seam is obtained. COPYRIGHT: (C)2009,JPO&INPIT
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