frames for attenuating slivers wherein one wrap winding apparatus is associated with each draw frame is proposed with the wrap winding apparatus further including a high speed rotor and a yarn channel coaxial with the axis thereof the rotor associated with a driven hollow spindle and a bobbin supported thereon and a balloon limiter supported on the machine frame by upstanding opposed ribs the bobbin supports a centrally apertured cap device with the cap device having a continuously curved convex end face with a sharply curved rim that merges with the end disc of the bobbin the aperture in the cap device is arranged to receive the feed of the winding thread and the sliver as it passes downwardly into the yarn channel and is emitted as a finished wrapped thread application_number US 13721080 A description this wrap winding spinning apparatus 10 has a bearing sheath 12 secured to a stationary rail 11 of the machine frame a bearing is held with restricted elasticity in the bearing sheath 12 and rotatably supports a foot shaft 13 which penetrates the sheath 12 of a hollow spindle 14 of a rotor 15 with a vertical rotary axis so that the rotor 15 can perform small radial swings for the purpose of performing centrifugal movements so that its course will be smooth these radial swings at the rotor head 20 embodied by a cap device 16 and the upper end disc 17 of a bobbin 26 of the rotor 15 are even in unfavorable cases smaller than 1.