Abstract: The present invention relates to an anti-loosening unit comprising at least one ringed plate. The ringed plate has slots, cuneal structures and protrusions. The cuneal structures match other corresponding cuneal structures of other corresponding elements. The slots serve to reduce the contact area of corresponding cuneal structures. With a small dragging force between the ringed plate and the other corresponding elements, the ringed plate slides easily to cause an axial displacement, thereby producing an axial stress. The axial stress will increase the friction between the protrusions and the element surface, so the anti-loosening unit is not easily rotated, and the anti-loosening effect is achieved. Furthermore, the slots of the ringed plate can reduce the deformation of the ringed plate, and the production quality is improved.

Abstract: A rotator for a twister for twisting yarn at more than two double twists for each rotation is provided. The rotator includes a rotating member, a stationary member and a tubular rod coupled together. Between a center rod and a point in an L-shaped passageway in the rotator and a bending point at a small guide wheel is produced respectively double twists to the yarn. A rectangular frame of the rotator member rotates with the rotator member so as to force the portion of yarn between a top hole in the frame and the bending corner of the L-shaped passageway to produce more double twists. Thus, at least two double twists are produced for each rotation of the rotator member to increase the speed of twisting yarn.