Thread cutting device in sewing machine

摘要

A thread cutting device in a sewing machine includes a movable knife which is movable across a space between a throat plate and a shuttle positioned below the throat plate so as to perform a thread cutting operation. A lower thread retreating lever is movable from a waiting position to an operative position for retreating a lower thread taken out from the shuttle to a position out of a thread cutting orbit of the movable knife. The thread cutting device is operable in either a thread cutting mode for cutting both an upper thread and a lower thread or a thread cutting mode for cutting only the upper thread by selectively positioning the lower thread retreating lever at either the waiting position or the operative position during the operation of the movable knife. An actuator and an interlocking mechanism between the actuator and the lower thread retreating lever are provided for driving the lower thread retreating lever. The actuator and the interlocking mechanism are positioned rearwardly of the shuttle.