GB118526A - Buttonhole Sewing Machine. - Google Patents

Abstract

118,526. Fairweather, W., (Singer Manufacturing Co.). June 14, 1917. Button-hole sewing machines.-Relates to buttonhole sewing machines of the type comprising a laterally jogging needle and rotary stitch-forming mechanism, and an intermittently rotated cam-wheel for imparting feeding and lateral movements to the work-holder, and consists in the means for forming the barring- stitches. After the formation of the last depth. stitch t<11>, Fig. 6, of the second side stitching operation and during the succeeding lateral movement of the needle, the work-holder is given a lateral jog in the opposite direction and a fulllength feed to lay the initial barring-stitch t between the point t" and the outer edge of the stitches s of the first side of the button-hole as shown. The work-holder then receives step-bystep reverse lateral movements, and the stitchforming mechanism rotary movements in the opposite direction to the rotary movements performed in stitching round the eye of the buttonhole, to lay the intermediate barring-stitches t<1>, after the final depth stitch puncture of which at t<13> the work-holder is given a full lateral jog in the same direction as the initial lateral movement to bring the work to the central position. During the formation of the barring-stitches, the workholder may be given a reduced feeding movement in the direction of the length of the button-hole, so that the outer line of the barring-stitches, during formation, may be slightly curved and, on tightening up the stitches, assume a substantially straight-line position transverse to the buttonhole, owing to the yielding of the fabric. The cam-wheel 26, Fig. 2, by which the feeding and laterally jogging movements are imparted to the work-holder and the rotary movements to the stitch-forming mechanism, is rotated step by step by the shaft 19, which is intermittently rotated from the main shaft 10 by an intermediate shaft carrying a disk 15 with two eccentricallyarranged pins 16 engaging teeth 22 on a disk 21 secured to the shaft 19. The teeth are formed at their outer ends with parts which are engaged simultaneously. with the pins 16 and, in this position, are concentric with the axis of rotation of the pins, and on their inner ends with inclined parts which are engaged by the pins alternately to produce the intermittent movement of the shaft 19. Specification 116,539 is referred to.