Abstract: A double-twist apparatus has a support provided with a journal in which is rotatably received a sleeve having an eccentric bore in which is centered the shaft of a twist spindle. A whorl carried on the shaft is engageable with a flat belt and rotation of the eccentric spindle within the fixed journal can move the whorl into and out of engagement with the belt. A lever is provided on the sleeve for angular displacement of this sleeve and a spring normally urges the sleeve into a position corresponding to engagement of the whorl with the belt or disengagement of the two. In the case of the spring urging the sleeve into the engaged position a toggle linkage is provided to hold the device in this position. In the arrangement where it urges the whorl away from the belt a spring-loaded device operated by a thread-tension sensor downstream of the apparatus is provided to stop the device in case of thread rupture. A brake is provided on the spindle shaft to arrest it when it is swung out of engagement with the belt.

Abstract: A thread is pulled off a yarn package and down past a thread brake into a spindle shaft forming part of a rotating structure. The thread exits at the bottom of the shaft from a radial opening in a payoff disk having a frustoconical surface formed with a peripheral groove. The thread passes from below across this groove and is then pulled up between the yarn package and a ballon-limiting cylinder. A reservoir disposed next to this structure is filled with a treatment liquid feeding an applicator whose upper end projects into the groove in the payoff disk. A wick in the applicator tube conducts the liquid up to the tip of the tube and moistens the thread as it passes periodically between this tip and the rotating disk.