weft yarn is absent and outputs a signal representing this fact in response to this signal the cutters 25a 25b are kept in an inoperative condition and the loom main shaft is stopped see steps s2 and s3 of fig3 in this case the loom main shaft is stopped at 180 u00b0 the maximum shedding state of the warp yarns in the next loom operational cycle after the beating up taking account of inertial motion as a result a mispicked weft yarn m for the warp yarn array ya and a normally picked weft yarn q which is picked simultaneously with the yarn m and for the warp yarn array yb are respectively being connected to the weft picking nozzles 8a 8b subsequently as shown in fig4 b the loom main shaft is reversely rotated by 360 u00b0 to establish a state in which the mispicked weft yarn m and the normally picked weft yarn q are respectively exposed at the cloth fells fa fb of the woven fabrics ca cb see a step s3 of fig3 next as shown in fig4 c air is ejected through the weft picking nozzles 8a 8b and the weft traction devices 20a 20b are operated supplying the weft yarns from the weft measuring and storage devices 12a 12b see a step s4 of fig3 this results in the fact that the weft yarns wa wb connected respectively to the mispicked weft yarn m and the normally picked weft yarn q are projected generally in the u shape into the shed opening of the warp yarns under the influence of air ejected from the weft picking.