The hand wheel could adjust the speed difference of two pulleys. The two pulleys are connected with the twin rewinding rollers separately. If there is speed difference between the two pulleys, there is also speed difference between the two rewinding rollers which could result in tight or loose fabric rolls. In this respect, the hand wheel could control the roll tightness through different speed.

手轮可以调节两个皮带轮的速度差。两个皮带轮各自和两个收卷辊筒连接，如果两个皮带轮有速度差，那么两根收卷辊筒的也有速度差，就能产生紧或松的布卷。所以，手轮可以通过调节速度差也控制松紧程度。