In a reversing-thread roller for textile machines, especially cross bobbin winders, with a groove taking a helical course and a traveller guided in the latter to move the thread guide to-and-fro, the groove from one reversing point to the next of the reversing thread roller has in developed form, a non-linear, i.e. curved course, and the curved course of the groove is so formed that, in use of the roller the coarsest pitch is provided after the traveller travels through the reversing arc bend, and the finest pitch is provided before the traveller passes through the next reversing bend. The pitch of the groove from reversing point to reversing point changes within a range of about 1 to 1.5 to about 1 to 1.3. In a preferred arrangement, the helically-running groove with curved course is a double groove with a central fillet, and the foot of the traveller has a central longitudinal slot matching the thickness of the central fillet of the double groove and lateral surfaces which are cambered in the lengthwise direction.
展开▼
