Automatic thread cutter for sewing machine with horizontal shuttle, includes command, cutting, gripping and regulating devices allowing cutting of both top and bottom threads or top thread only

摘要

An automatic thread cutter for a sewing machine with a horizontal shuttle (3) includes first and second command devices for generating signals to cut both the top and bottom threads (29u, 29d) or the top thread (29u) only respectively; a thread cutter (5, 14); a thread gripper (4), actuated by the signals to move along predetermined paths; and a thread regulator (7) actuated by the first signal. An automatic thread cutter for a sewing machine with a horizontal shuttle (3) includes first and second command devices, for generating first and second signals to cut both the top and bottom threads (29u, 29d) or the top thread (29u) only respectively; and a cutter (5, 14) for the gripped top and bottom threads. A thread gripper (4), actuated by the signals to move along predetermined paths, seizes the top and bottom threads on receiving the first signal; or moves to and fro to grip the top thread and move simultaneously under the bottom thread on receiving the second signal. A thread regulator (7), actuated by the first signal, moves the bottom thread downwards, to be seized by the gripper during its to and fro motion.