US Patent 8020502 Thread cutting device of sewing machine

The thread cutting device of a sewing machine provides a first thread catching member having a first thread catching portion for catching a thread positioned between the horizontal shuttle and the needle hole and carrying out forward and backward movements below the throat plate while the first thread catching portion catches the thread, a second thread catching member having a second thread catching portion for catching the thread laid between the needle hole and the first thread catching portion and guiding the thread caught by the first thread catching member to a fixed blade and to cut the thread by the fixed blade.