Method of monitoring the supply of looper thread of a double lock-stitch sewing machine

摘要

PCT No. PCT/EP91/01320 Sec. 371 Date Dec. 15, 1992 Sec. 102(e) Date Dec. 15, 1992 PCT Filed Jul. 13, 1991 PCT Pub. No. WO92/02673 PCT Pub. Date Feb. 20, 1992.Fastened to the bobbin for reception of the supply of looper thread which is inserted in the looper of a sewing machine, there is a data carrier (22) in which there is stored data which describe the supply of looper thread present on the bobbin with respect to the amount thereon and possibly also the nature of the sewing thread wound thereon. The data carrier is scanned by a sensor which preferably includes a first read/write head (27) and a second read/write head. After the winding of an empty bobbin, the data defining the supply of looper thread is recorded by said second read/write head in the data carrier of the said bobbin. After the sewing has been effected, the data defining the existing supply of looper thread is entered/read with the first read/write head in/from the data carrier of the corresponding bobbin. Thus, the bobbin provides information at any time as to the supply of looper thread present on it.