Ultrasonic thread cutter for sewing machine - has flexible horse shoe-shaped cutting head coupled to piezoelectric crystal vibrator

摘要

The ultrasonic thread cutter may be deployed on a sewing machine and has a flexible horse shoe-shaped cutting head. The opposed internal zones incorporate the cutting faces, and the head is coupled to an ultrasonic vibrator. The cut is effected by relative vibratory motion of the cutting faces with the thread locating between the faces. The cutting faces are pref of reciprocal geometric and slightly spaced from each other and make contact under vibration. The contact under vibration sets up secondary vibration of the legs of the head. The vibrator pref. comprises a resonant support housing an electrically animated tubular piezoelectric crystal.