| 摘要 |
<p>A device for the automatic control of the weft yarn feed in air looms comprises one or more sensors (13), which pick up the time taken for each yarn turn or turn section leaving the feeder to unwind, and a picking up and analysing circuit (14) receiving the signals from said sensors (13), said circuit being associated to a programmable control circuit (15) which controls the solenoid valves (7, 8, 9) feeding air to the loom nozzles (1, 2, 3). Said device is apt to vary certain parameters (operating period of the nozzles, strength and length of the air blasts blowing from said nozzles) in respect of the programmed working parameters any time the weft yarn motion law changes in respect of the one programmed, so as to obtain a yarn feed equivalent to that which would have been obtained on the basis of said law. Said device is also apt to influence said programme any time a specific high production standard has been achieved, so as to modify the programme itself for energy saving purposes.</p> |
