Weft inserting channel for pneumatic weaving machines

Claim 1

In a pneumatic weaving machine forming successive sheds, a weft inserting channel for pneumatically inserting weft into the successive sheds, said channel including aligned active and passive sections, said active sections having weft inserting openings of substantially circular cross-section, said active sections each having a directing profile forming at least a part of its weft inserting opening, each of said active sections having a front wall facing in the direction of weft inserting and having discharge openings arranged around said weft inserting opening therein, each of said passive sections having a weft inserting opening of substantially circular cross-section, the weft inserting openings of all of the active and passive sections lying on a common axis, which is also the axis of the channel, said passive sections being arranged between successive active sections, said passive sections having a directing profile arranged In said weft inserting openings thereof, a pressure air jet weft-inserting nozzle arranged at the rear end of the channel and directing a jet of air in the forward, weft inserting direction, a source of pressure air coupled with said pressure air jet weft-inserting nozzle, a source of additional pressure air coupled with said discharge openings of said active sections, the radial distance of the directing profile from the common axis of at least one passive section adjacent an active section in the direction of web insertion being no less than the radial distance of imaginary lines connecting tangential points of the directing profile of the following active section with the points of intersection on said front wall of the preceding active section, and the radial distance of said points of intersection from the common axis of the channel being longer than the radial distance of said discharge openings of said active sections.