WEFT YARN STORING, FEEDING AND MEASURING DEVICE FOR JET WEAVING MACHINES

摘要

This device has a storage drum (2) onto which an intermediate weft yarn store can be wound by a winding-on member (3) and from which the weft yarn (WY) is withdrawn spiralling around the withdrawal end of the storage drum, at least one yarn stopping device (10/14) being arranged at said withdrawal end and consisting of a stopping element (14) and of actuator means (11) moving said stopping element into and out of the path of the yarn being withdrawn, and an actuator control unit (B) transmitting an acutating signal to said stopping device when a weft yarn length corresponding to the length of the shed (WMS) of the woven fabric in the machine has been withdrawn from the storage drum. The actuator control unit (B) is electrically connected to a yarn sensing detector (WD), preferably of optical type and known per se, positioned at the arrival end (AE) of the shed (WMS) for the weft yarn (WY) at a predetermined distance (d) from said arrival end. Thus, the control unit (B) receives an electric signal when the inserted weft yarn (WY) reaches the yarn sensing detector (WD) and in response thereto generates and transmits the actuating signal to the actuator means (11) of said yarn stopping devices for stopping the withdrawal of the weft yarn from the storage drum (2).