a cover 20 the fiber material is conventionally supplied as a sliver 3 to a fiber supply and resolving device which is shown schematically in fig1 as a pair of supply rollers 4 and a supply tube 40 fibers 31 supplied to the annular collection surface 10 of the spinning rotor is spun onto the end 32 of a thread 30 the thread is drawn off through a tube 5 by drawoff rollers 6 tube 5 is disposed coaxially with the rotor 1 and has a mouth 50 at its infeed end leading to a cylindrical axial bore 52 the mouth 50 includes a curve 51 about which thread 30 32 bends thread 30 is held by the nip of drawoff roller 6 so that the thread cannot rotate about its axis the free thread end 32 which extends from the mouth 50 of the drawoff tube 5 to the fiber collection surface 10 is turned by centrifugal force created by the rotation of spinning rotor 1 and acts as a crank which creates twist in the stretch of thread 30 extending between drawoff rollers 6 and mouth 50 of the drawoff tube it is important that this twisting or torsional force be transmitted to the thread portion 32 to bind in the fibers received by it at the fiber collection surface 10 however because the thread is bent as it.