| 摘要 |
PURPOSE: To provide a sewing machine equipped with a needle thread controller for making the peak characteristic of needle thread tension with the up of a needle thread take-up almost equal with the thread of different extension characteristic such as thread type. CONSTITUTION: In an upper needle dead point phase represented by a phaseθa, a needle thread presser 39 excites a solenoid 42, pulls a plunger 43 in the direction of arrow A against the energization of a spring 45, presses a thread holder 41 to a thread hold tray 40 through a pin 44, presses and holds a needle thread 5 guided between them. From this upper-needle dead point phaseθa to a needle thread take-up upper dead point phaseθ1 , a needle 17 moves down but a needle thread take-up 35 moves up and the thread of stitches is fastened. When a phase detected by a phase detecting means 34 reaches a phaseθ2 set to a storage device 49 beforehand, a signal is outputted from a central processing unit 46, and the solenoid 42 is operated. According to this signal, the excitation of the solenoid 42 is released.
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