Patent ID: 8418506

Claim:
A method for automatically evaluating the yarn length absorbed by a rectilinear machine to produce an article, the machine comprising a needle bed and a carriage; comprising the steps of: moving, above the needle bed, said carriage carrying at least one thread guide, said carriage moving between two ends of a working path in accordance with a first and a second operative phase which take place along opposing movement directions, during this movement said carriage selectively raising and lowering, from and into said bed, needles arranged to cooperate with said yarn to form the article, unwinding said yarn from a feeder, this feeder comprising means for measuring the yarn quantity fed towards said needle bed, yarn feed taking place at constant tension, the feeder measuring the yarn feed velocity during each operative phase, and if this feed velocity is greater than a threshold value the yarn quantity fed in the respective operative phase is measured until said feed velocity attains a value less than the threshold value, the values of these quantities measured during each operative phase being algebraically added to a value relative to the yarn quantity fed to the carriage during each phase to enable the carriage to pass from one end to the other of the working path and vice versa, from this algebraic sum there being determined the yarn quantity effectively fed to the needles for article production during each operative phase.