| 摘要 |
A thread tension device includes a pair of discs engaged on a shaft and a spring for biasing the discs to clamp a thread. A follower is threadedly engaged on the shaft for adjusting the spring. A barrel is engaged with the follower so as to rotate the follower. A cap is rotatably engaged on the barrel. A latch is slidably engaged in the barrel for engaging the barrel with the cap so as to allow the barrel and the cap to rotate in concert when the latch is engaged with the cap. The barrel is allowed to rotate freely relative to the cap when the latch is disengaged from the cap.
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