Automatic picking conditions regulating method and a device for carrying out the same

An apparatus which automatically regulates a picking condition of a loom which has a crankshaft and which picks a weft yarn into a shed using a jet of picking fluid from a picking nozzle, comprising:

• command means for sequentially providing a plurality of predetermined values of the picking condition;
• control means for varying the supply of the picking fluid from a fluid source to the picking nozzle according to the different predetermined values of the picking condition provided by the command means;
• weft yarn arrival detector means for detecting the crankshaft angle at which a picked weft yarn arrives at a predetermined location in the shed;
• memory means for storing the predetermined values of the picking condition provided by the command means and the corresponding weft yarn arrival crankshaft angles detected by the weft yarn arrival detector means;
• target setting means for specifiying a target weft yarn arrival crankshaft angle appropriate for a normal weaving operation;
• and
• arithmetic means for calculating an appropriate value of the picking condition corresponding to the target weft yarn arrival crankshaft angle specified by the target setting means on the basis of the correlation between the detected weft yarn arrival crankshaft angles stored in the memory means and the predetermined values of the picking condition stored in the memory means, and for providing the calculated value of the picking condition to the control means, the control means thereafter controlling the supply of the picking fluid to the picking nozzle in accord with the calculated value of the picking condition.

An apparatus for automatically regulating a picking condition of a loom which has a crankshaft and which picks a weft yarn into a shed using a jet of picking fluid from a picking nozzle, comprising:

• weft yarn arrival detector means for detecting the crankshaft angle at which each picked weft yarn arrives at a predetermined location in the shed;
• command signal means for providing a command signal at predetermined intervals during weaving;
• picking condition command means for providing, following one occurrence of said command signal from the command signal means, a plurality of signals defining a progressive change of the value of the picking condition over several picking operations by successive predetermined change amounts so that the picking condition is varied within a range which has a negligible effect on a fabric woven by the loom;
• memory means for storing the values of the picking condition used during said progressive change thereof and for storing the corresponding detected weft yarn arrival crankshaft angles;
• arithmetic means for determining a correlation between the stored values of the picking condition and the stored weft yarn arrival crankshaft angles, and for calculating an appropriate value of the picking condition on the basis of the correlation;
• and
• control means for controlling, after said one occurrence of said command signal, the supply of the picking fluid from a fluid source to the picking nozzle first on the basis of the plurality of signals from the picking condition command means and thereafter on the basis of the calculated value from the arithmetic means.