One could also say that the auxiliary blowing nozzle keeps the yarn length, which remains behind in the weft inserting device, under tension, due to which said yarn length will be able to withstand the untwisting action of the air supplied to the main nozzle. As a consequence, the forces imposed by the air on the weft yarn in the weft inserting device is more evenly distributed along the overall length of the weft inserting device.
This means, that the amount of air required for the insertion of the weft yarn into the weaving shed is supplied to the weft inserting device at at least two locations, which are spaced one from the other as seen in the inserting direction.
Inklet weaving length series#
For this purpose according to the invention at least one auxiliary blowing nozzle is arranged in series between the outlet end of the main blowing nozzle of the weft inserting device and the adjacent end of the weaving shed, there being a free space between the outlet end of the main nozzle and the inlet end of the auxiliary nozzle, through which the air stream from the main blowing nozzle laterally escapes.
The present invention aims at overcoming said drawbacks. In both cases, however, the next weft inserting phase will result in a weaving defect, because the yarn piece, which should have formed the leading end portion of the next weft, has disappeared. In the most favorable event such yarn length will then be transported by said auxiliary blowing nozzles toward the usual suction device located at the opposite side of the weaving shed, so that the said yarn length will be discharged by said suction device. It may also occur that the said yarn length will be broken from the yarn supply only at the start of or during the next weft inserting phase and then be blown through the weaving shed as a separate piece of yarn or mass of fibers by means of the usual auxiliary blowing nozzles located in spaced relationship across the width of the shed. This untwisting and weakening might take place to such an extent that the yarn length is severed from the yarn supply and may be finally blown into the weaving shed as a disintegrated mass of fibres, which of course means quite a disturbance of the weaving process. (- WHEN THE YARN SUPPLY TO THE BLOWING NOZZLE IS INTERRUPTED AND THE INSERTED WEFT THREAD IS CUT THROUGH AT A LOCATION BETWEEN THE OUTLET END OF THE BLOWING NOZZLE AND THE ADJACENT END OF THE WEAVING SHED), REMAIN BEHIND IN THE BLOWING NOZZLE BEING UNTWISTED TO A CONSIDERABLE EXTENT AND CONSEQUENTLY SUBSTANTIALLY WEAKENED BY THE CONTINUED AIR STREAM OR BY THE REMAINDER OF THE AIR STREAM THROUGH THE BLOWING NOZZLE. With weaker yarn types this might result in that the yarn lengths which, upon completion of a weft inserting phase The invention relates to a pneumatic weaving machine of the type in which an air fed weft inserting device constituted by a blowing nozzle cooperates with a device arranged upstream of its inlet and adapted to intermittently interrupt the inserting motion of the weft yarn effected by the nozzle.īecause of increasing production speeds the weft yarn in such weaving machines is more heavily attacked by the forces imposed on it by the air stream of the weft inserting device.
A weaving machine according to claim 1 wherein the length ratio between the main and auxiliary nozzles is between 1:2 and 1:4.
A weaving machine according to claim 1 wherein the machine has a frame and a lay and the main blowing nozzle in mounted on the frame and the auxiliary blowing nozzle is mounted on the lay.Ĥ. A weaving machine according to claim 1 wherein each of the nozzles has a mixing tube and the distance between the two nozzles is one to two times the lineary cross sectional dimension of the mixing tubes.ģ. A pneumatic weaving machine having air fed apparatus for inserting a weft into a weaving shed and which includes a main blowing nozzle and at least one auxiliary blowing nozzle, each having a weft inlet and a weft outlet, and being located adjacent to and outside of one end of the shed, the auxiliary blowing nozzle being arranged in series between the weft outlet of the main nozzle and the adjacent end of the shed, there being a free space between said outlet and the weft inlet end of the auxiliary mozzle through which the air stream from the main blowing nozzle laterally escapes.Ģ.
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