Weft picking device of air jet type weaving loom

A weft picking device of an air jet type weaving loom, having a plurality of air guide members which are aligned in the weft picking direction, each guide member having therein both a tapered air guide opening through which the weft yarn passes upon weft picking, and a slit through which the weft yarn passes out upon beating, the tapered surface of the air guide opening of each air guide member being tapered toward the weft picking direction, and wherein said plurality of air guide members comprises:

• a nozzle-mounted air guide member having around the air guide opening thereof a plurality of air ejection holes from which compressed air is ejected in the weft picking direction to establish an auxiliary air flow;
• a first group of air guide members located downstream of said nozzle-mounted air guide member and positioned between the nozzle-mounted air guide member and the point at which the inboard boundary of the auxiliary air flow from each air ejection hole intersects the axis of the air guide channel of the aligned air guide members, the air guide openings of the first group air guide members being larger than the air guide opening of said nozzle-mounted air guide member and gradually reduced in diameter as the distance from the nozzle-mounted air guide member increases;
• and
• a second group of air guide members located downstream of said first group of air guide members, the air guide openings of said second group air guide members being identical to one another and to the air guide opening of said nozzle-mounted air guide member.