Weft Handling Device without False Edges in Projectile Weaving Machines

Abstract

A weft handling device of the type in projectile looms, comprising: for each of the weft threads waiting for each of the weft yarns a respective clamping gripper mounted on the same single support On, a support is arranged at the edge of the fabric being woven; a first motor device which moves said support so as to bring the clamping gripper of the weft thread to be inserted into the shed close to the work station; a second motor device which, together with A holding device acts oppositely to open the clamping grippers, the holding device maintains the clamping grippers in a closed position; and a weft thread guiding device, which transports the weft yarn into the opened clamping grippers during the beating-up step . The support pivots around a rotation axis, and the clamping grippers are mounted on the support along a circular arc centered on said rotation axis. A thread guiding device is provided, integral with the support, for passing all the weft threads gripped by the clamping grippers through a converging area, which is arranged next to the axis of rotation of the support.

Description

technical field [0001] The invention relates to a weft thread handling device in a projectile loom without at the same time requiring the formation of a false edge on the supply side of the loom. The weft thread handling device according to the invention can also be used in projectile weft insertion looms, where the projectile is provided with a weft thread clamping and weft thread release function for the running projectile, for example in European Patent Application No. 18176734.4 in the name of the same applicant as disclosed. [0002] As known to those skilled in the art, the term "false edge" refers to an additional set of warp yarns placed on and spaced from both sides of the warp yarns intended to form the fabric At a certain distance, the warp threads are usually interwoven with the weft threads by a simple cloth weave, which is therefore different from the weave used to manufacture fabrics. [0003] One purpose of the false edge is to create between the regular warp...

AI Technical Summary

Problems solved by technology

However, from a textile point of view, this solution has an obvious disadvantage, namely, said solution does not allow to maintain a constant tension of the waiting weft thread, because the length of the channel of the waiting weft thread depends on the clamping gripper module The continuous movement changes

There is therefore often the possibility of loosening the waiting weft yarn, which can lead to failure of the carrying gripper to hold the weft yarn and weft yarns that are actually very close to each other to become entangled

Furthermore, since in this solution the weft-thread clamping grippers are arranged in series and are held in the closed position by a common, individual spring, no independence of the clamping force can be achieved for each individual clamping gripper adjustment, the independent adjustment of the clamping force is often desired in the presence of different types of weft yarns

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