| 摘要 |
PROBLEM TO BE SOLVED: To provide a thread tension adjuster which can facilitate to adjust rotational resistance applied to a thread wheel or the like, by applying the rotational resistance to the thread wheel or the like while reducing the resistance. SOLUTION: An inner ring of a thrust bearing which is provided on a shaft that rotates integrally with the thread wheel, receives pressing force from an outer ring of the thrust bearing via the thrust bearing 130, and the pressing force becomes rotational resistance against rotation of the thread wheel. The pressing force is generated by a piezoelectric element or by a pressure spring. Since rolling elements 134 also rotate along with the rotation of the thread wheel and the shaft, the rotational resistance is reduced. Besides, a rolling axis of the rolling element 134 has an angleθto a radial direction of a holder disk 132, accordingly, though the rolling element 134 has a tendency to roll and move in the direction indicated by an arrow A, the actual moving direction of the rolling element 134 is directed in the direction indicated by an arrow B in accordance with the rotation of the thread wheel, whereby the resistance according to an angle difference between both directions is added. Therefore the rotational resistance is moderately reduced. COPYRIGHT: (C)2004,JPO
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