Underwinding-thread clamp for a ring-spinning or ring-twisting machine

摘要

An underwinding thread clamp for a spindle of a ring spinning or ring-twisting machine has a clamping sleeve biased by a spring against and juxtaposed with a collar on the spindle. The juxtaposed surfaces of the spindle and collar have wavy contours so that, upon engagement of an actuating member with each collar, the latter is cammed into its open position to release the respective underwinding thread so that the latter, engaged when a full bobbin was removed, can be released. The clamping of the underwinding thread permits the thread to be wound on the newly mounted core sleeve.