Thread cutting device for a sewing machine

摘要

A thread cutting device for a sewing machine with a hook rotatable in a vertical plane includes a drive motor, a fixed knife which has a working-side wall extending towards a thread fetching zone of the sewing machine to terminate at a first cutting edge, and a movable knife which is driven by the drive motor to angularly move between fetching and thread cutting positions in a vertical plane. The movable knife has a lateral edge surface defining a cavity in an intermediate segment thereof to engage lower and upper threads when the movable knife reaches the fetching position. The movable knife has a second cutting edge disposed to press the first cutting edge so as to complete a cutting action.