| 摘要 |
PROBLEM TO BE SOLVED: To provide a thread tension device, capable of suitably adjusting the tension of a thread and the amount of thread used. SOLUTION: A piezoelectric element 106 generates elongating force according to the supplied voltage, a pre-load spring 110 generates energizing force regardless of the voltage supply to the piezoelectric element 106. The resultant of forward forces by the pre-load spring 110 and the piezoelectric element 106 is applied through two, front and rear thrust bearings 130, 136, so that cylindrical rolling elements 134, 140 are also rotated with the rotation of a thread pulley 102 and a shaft 104 to decrease rotational resistance to the rotation of the thread pulley 102 and the shaft 104. COPYRIGHT: (C)2003,JPO
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