| 摘要 |
A precise, accurate and sensitive control method and system for actuating the stop motion mechanism of a weaving loom equipped with a weft yarn storage feeder unit is disclosed. The storage and feeder unit includes a device for applying tension to the weft yarn being delivered from a weft yarn supply to the storage and feeder device. The tension device is equipped with a switch which provides a first electrical signal when the weft yarn being supplied to the storage and feeder device becomes slack or interrupted. That switch is connected with the weft yarn storage and feeder unit motor circuit. The weft yarn storage and feeder unit may be intermittently driven as the need occurs for feeding a weft yarn length or pick into the loom. The loom is stopped only in the presence of two concurrent signals, namely (1) a signal generated upon the detection of slack weft yarn or the absence of yarn in the tension device and (2) a simultaneous signal indicating operation of the motor to drive the weft yarn storage and feeder device. By the operation of the loom stop motion mechanism only in the presence of the aforementioned simultaneous signals, short picks, i.e., insertion of weft yarn lengths less than that required to extend from one side of the fabric being woven to the other, is precluded. Further, false signals which might arise from simple slackening of the yarn in the zone of the tension device are not operative to halt the loom. |
