3d2 there correspond fig3 a1 to 3d1 with identical index a b c d in this case the bridges 4c instead of being perpendicular to the plane of the drawings as in fig3 a1 to 3d1 the pairs of adjacent segments 4a and 4b being thus superimposed are on the contrary parallel to the plane of fig3 a2 to 3d2 so that they are visible thereon and several pairs of consecutive segments 4a and 4b are also visible of course the relative movement of needle 3 1 with respect to support 1 does not necessarily take place in one of the directions f1 or f2 such a relative movement could take place in any other direction for example at 45 u00b0 with respect to f1 and f2 in addition it will be understood that this relative movement is not necessarily linear and that it may follow a curved path such as circular helical spiralled etc or else a combination of such paths in fig4 and 6 a first variant 3 2 of needle 3 1 has been shown needle 3 2 is also circular with center 5 however instead of being hollow it is solid and comprises a thread guide groove 14 along its convexity on the same side as its point 8 it has an eye 15 turned towards its concavity and in communication through a passage 16 with said groove 14 it will be readily understood that needle 3 2 operates in a similar way to needle 3 1 fiber 4 being guided by groove 14 and through eye 15 see fig4 instead of being guided by the internal channel 6 the second variant 3 3.