| 摘要 |
<p>The object of the present invention is to provide a thread tension controller for sewing machine, which may directly control the tension itself exerted on the thread and can sustain and control the tension as a preset line tension regardless of the thread type or thickness, elongation properties, as well as time-varying of the controller. The controller has: a thread modulating plate of coiling threads, an impulse motor setting the thread modulating plate on the motor output shaft, an encoder section, an impulse motor drive section, a thread tension setting section, a phase difference detection section and a table denoting the relationship between the set thread tension and the rotating phase difference corresponding to the line tension, which is characterized in that a driving signal is exerted to the impulse motor to rotate the impulse motor, so at to maintain the rotating phase difference between the thread modulating plate and the output shaft of the impulse motor caused pull wires, as the size identical to the rotating phase difference of the thread tension.</p> |
