Patent ID: 6672232
Filing Date: 2004-01-06
Classification: D05B

Abstract:
A two-thread lock-stitch sewing machine, comprising:a sewing needle (10), which carries a needle thread (13) and is movable to reciprocate up and down along a motion travel (11); a bearing plate (16; 16â€²) for a workpiece (17); a feeder (19; 19â€²); a stitch hole (20; 20â€²) formed in one of the bearing plate (16; 16â€²) and the feeder (19; 19â€²) for the sewing needle (10) to pass through; a shuttle (21), which is arranged underneath the bearing plate (16; 16â€²) and rotatably lodged in a bearing block (30), and which has a shuttle body (22), which is rotatable about a vertical axis (29) and which is provided with a rotatable bobbin case (24) and supplies (25) of a shuttle thread (27); two stationary cams (48, 49; 48â€², 49â€²), which are disposed in proximity to the stitch hole (20; 20â€²); a holding finger (43), which is provided on the bobbin case (24) and has an end (44) located between the cams (48, 49; 48â€², 49â€²); a thread cutter (42) with a thread pulling knife (38), which is movable to reciprocate between a swung-out position (A) and a swung-in position (E), performing a cutting motion in an x-y plane that extends at right angles to the vertical axis (29), which comprises a hook (39), which seizes the threads (13, 27), and a cutting edge (40), and which, in the swung-in position (E), is movable into a space (64) between the motion travel (11) and the cams (48, 49; 48â€², 49â€²); wherein the thread pulling knife (38) is formed on the free end of a lever arm (36) which is connected to a shaft (33) that is parallel to the vertical axis (29), and which is movable above the bobbin case (24); wherein the cams (48, 49; 48â€², 49â€²) are disposed on a rib (46; 46â€²), which has an upper surface (50; 50â€²) that is substantially parallel to the x-y plane; and wherein the bearing plate (16; 16â€²) is provided with a lower surface (62; 62â€²) that is substantially parallel to the x-y plane, with the lower surface (62; 62â€²) and the upper surface (50; 50â€²) being disposed at a distance (a) from each other that is measured at right angles to the x-y plane, forming an interspace (63) for the lever arm (36) to pass through unimpeded for the performance of the cutting motion.