GB769358A - Improvements in or relating to zig-zag sewing machines - Google Patents

Abstract

769,358. Sewing machines. SOC PER AZIONI FRATELLI BORLETTI. Feb. 25, 1955 [March 30, 1954], No. 5777/55. Class 112. Needles, shifting laterally; needles, driving. In a zig zag sewing. machine in which a needle bar both reciprocates and swings transversely, the needle bar is mounted in a support connected by a leaf spring to the machine frame, a second leaf spring couples the needle bar to a rod adapted to impart swinging movement thereto, and a third leaf spring connects a ball and socket joint on the needle bar to a crank pin adapted to impart reciprocatory movement to the latter. As shown, the needle bar 2 is slidably mounted in a bracket 1 which is connected at its upper end by a leaf spring 4 to the machine frame 3. Bracket 1 is swung by means of a rod 7 connected at its forward end by a leaf spring 8 to the bracket and secured at its rear end to a member 12. The latter has a forked end which embraces a cam 13 mounted on a vertical shaft 14 which is driven by the upper shaft 15 of the machine. Member 12 is pivoted on a pin 18 fixed by a screw 18<SP>1</SP> to a rod 16 slidably mounted in bearings 17, rod 16 passing through an ovalshaped opening 19 in member 12 to allow the latter to pivot relative to rod 16. The needle bar is driven from a crank pin 24 carried by shaft 15 and connected by a leaf spring 25 to a ball and socket joint 21 carried by the needle bar. In a modification, the needle-barcarrying bracket is connected to the frame by a pair of leaf springs so as to swing about a vertical axis.