GB529334A - Improvements in and relating to sewing machines - Google Patents

Abstract

529,334. Sewing-machines. NAHMASCHINENFABRIK KARLSRUHE AKT.-GES. VORM. HAID & NEU. May 30, 1939, Nos. 15858 and 15859. Convention dates, May 31, 1938, and March 4, 1939. [Class 112] Needles, vibrating laterally. - Mechanism giving a variable lateral vibration to the needle. arranged so that the stitches may be disposed symmetrically upon the line of sewing or entirely to one or other side of that line, is adjustable during stitching by means of a lever 46 which does not participate in the vibrations. The swinging needle-bar frame is coupled by a rod 39 to a block sliding in a slotted guide 31 carried by an oscillating lever 26. The guide is pivoted upon the outer extremity of the lever and is anchored, at a point in line with the axis of the lever, by a link 48 to an adjusting lever 46. With the lever 46 in its mid-position and the mechanism in its mean position, the slotted guide is concentric with the needle frame end of the rod 39 so that movement of the block upon the slotted guide 31 does not shift the centre of the zig-zag stitches. With the lever 46 moved to one side, the pivot 51 is moved laterally of the axis of the lever 26 and the centre of the zig-zag stitches changes with changes in the extent of the lateral vibrations. The block is connected by a link to a lever 77 in gear-tooth engagement with an adjusting hand-lever. The latter has an arm 75 which co-operates with a spring 76 having a central recess 77 and with adjustable screw stops which limit the maximum vibrations. The link 48 and pins 49 may be replaced by a suitable cam-slot in the lever 46 which engages the pin 51.