Stitch forming element control using _stepping motors which can be calibrated

摘要

Disclosed is an improvement in a sewing machine supplied with stepping motors for the generation of setting movements of the stitch forming elements. A mechanical stop is provided in order to permit the stepping motors to be calibrated against the stop and thus provide precise settings of the stitch forming elements. Protection against jamming is provided by the use of elastic members between the coupling arm and linkages such that the elastic members absorb external forces against which the stepping motor is to be protected in order to keep the calibration intact. Additionally disclosed is an apparatus for setting the stepping motor either in whole steps or in arbitrary intermediate steps which are actually between two discrete stable positions.