the cavity 6a of the winding arm 6 shears or cutters 16 16a to cut the yarns controlled by actuators 17 and respectively 17a furthermore a duct 21 branches off from the duct 18 the duct 21 communicates with the exterior and ends with a nozzle 24 into which compressed air can be let from a duct 22 by opening a solenoid valve 23 so as to produce a suction pressure and suck the weft yarn out of the duct 18 removing it according to the invention a second pneumatic device 30 is applied on the weft feeder to the side of its yarn reserve winding drum the device of which fig3 shows a longitudinal section view comprises a fixed duct 25 positioned along the projection 2a of the weft feeder 2 this is a curved and suitably profiled duct meant to guide the yarn 4 coming from the inner cavity of the winding arm 6 towards a fixed point from which the main nozzle of the loom is fed in fig3 the fixed point is the yarn guide eyelet 31 positioned outwardly along the axis of the weft feeder the eyelet 31 could also be the inlet of the main nozzle 3 of the loom or the inlet to a third auxiliary pneumatic device 40 described hereinafter the outlet 26 of the inner cavity of the winding arm 6 fig3 should face the inlet of the fixed duct 25 so that air and.