Nozzle device for producing a fluid jet

Claim 1

Nozzle device for producing a jet of fluid for inserting weft threads into a shed on a loom, the said nozzle device comprising an inner portion and an outer portion symmetrically surrounding said inner portion, said inner and outer portions defining a ring shaped nozzle aperture for a jet of fluid to flow out, there being defined between the said inner portion and the said outer portion a chamber which contains the weft thread propelling fluid, said outer portion being formed with a plurality of apertures for supplying the fluid to said chamber from a fluid source, said chamber having a front and a rear zone with its front zone extending rearwardly away from said nozzle aperture and forming an ''''aiming'''' portion for determining the direction of the flow of said jet of fluid, and which is prolonged by said rear zone forming a storage portion, the apertures for supplying the fluid to said chamber being located in said rear zone remote from the nozzle aperture, said aiming portion being elongated and delimited by two walls at least one of which is conical and that converge with respect to each other to produce a substantially uniform decrease in the cross-section of the aiming portion in the direction of the nozzle aperture, a bore in said inner portion for passage of said weft thread to be propelled by said jet of fluid passing from said nozzle aperture, and a means for supplying said fluid flow to said chamber.