pat no 39 513 u201c airfoil u201d or airplane wing would be even more favorable however the ovoid and symmetric profiles according to the invention have the very useful feature in practice of permitting the use of the machine in clockwise or counter clockwise mode without having to dismantle it a reduction of noise due to the said reduction of drag may attain u2212 2 5 db at high speed see table 1 an improvement of the resistance per unit length of the cables in other words a reduction of the losses of diameters is also observed the measurements are similar at 5000 rpm but above there is a distinct advantage in favor of the flyer bow according to the present invention micro bulge effect of the spring when the wire is centrifuged for example production at 5700 rpm with the standard flyer bow may be achieved at 6100 rpm with the same final product quality i e a 7 productivity gain it is also possible to envision placing a reinforcing and protective element ep in the internal tube or orifice o in other words the tubular conduit made in the thickness of the flyer bow between the said internal tube and the cable guide element rs this reinforcing element.