in the number of false twist ribs which may be provided as represented on fig2 the two additional false twist ribs 42a 42b might be located approximately 20 u00b0 on both sides of the central rib 42 the dihedral angle t of the detachable member extending about 60 u00b0 the elbowed tube 16 is subjected to the partial vacuum which prevails within the rotor 1 with the result that the spinning process may conveniently be initiated by introducing a yarn end into the elbowed tube 16 through the eyelet 17 said yarn end is sucked towards the rotor 1 and passes readily into the elbowed portion 16b of the tube by reason of the fact that the false twist rib 42 is inclined and extends only over one half of the circumference of the tube whereas the other half is perfectly smooth when the spinning process has been initiated the textile yarn 13 is drawn by conventional takeup means not shown in the drawings and consequently tends to be applied against the generator line having the shortest radius of curvature of the elbowed portion 16b of the tube the yarn therefore slides successively against the inclined ribs 42a 42 and 42b and is subjected by frictional contact with these ribs to a reaction which has the effect of temporarily increasing its torsion as a result of a false twist phenomenon which is subsequently lost as it passes out of the elbowed tube 16 but which has had the time to assist the spinning process and to improve the quality of the yarn as is already known it will readily.