| 摘要 |
<p>The device is arranged upstream of a textile machine (12) for temporarily recovering a lenght of yarn previously fed to the machine, and for returning it subsequently. A motorized reel (18) has a substantially axial inlet port (28a) and an outlet port (28b) on its lateral surface (18b), with a passage (28) for the yarn (F) between the ports. The reel (18) is operatable to rotate from a resting configuration, in which it is kept still, to an active, yarn-recovering configuration, in which it is driven in one direction for winding the yarn on itself and recovering it from the machine (12), to a subsequent active, yarn-unwinding configuration, in which it is driven in the opposite direction for unwinding the yarn from itself and returning it to the machine. A position sensor (SP) measures the position of the reel (18) and sends a corresponding measured position signal (meas_pos) to a position control loop (PL) which compares the measured position signal (meas_pos) with a reference position signal (ref_pos) corresponding to a desired position for the motorized reel (18), and drives the reel in such a way as to minimize the difference between the measured position and the desired position.</p> |
