GB947577A - Improvements in or relating to sewing machines - Google Patents

Abstract

947,577. Sewing-machines. ANKERPHOENIX NAHMASCHINEN A.G. Jan. 8, 1960 [June 19, 1959], No. 829/60. Heading D1G. The manual controls for setting the stitch width and position of a zig-zag sewing machine are arranged to be coupled and to also control the stitch direction so that when placed in three successive positions the controls cause the stitch to produce, successively the stitches along one side of, the barring stitches for, and the stitches along the other side of a buttonhole. Feeding work (Fig. 3). A feed bar 67 derives its feed lift movement from a lifting element 68 embraced by a jaw at one end of the feed bar and its feed advance movement from a crank 65 mounted on an oscillating feed advance shaft 64 and pivotally connected to the other end of the bar. The shaft has an arm 63 connected at 62 to one end of an element 61 embracing a cam 60 on the looptaker shaft 58. A block pivotally mounted on a pin 70 at the other end of the element slides in a groove in a spring biased pivoted member 74. The angle at which the member 74 is set determines both the stitch length and direction of stitching caused by the feed dog 69, and this angle is set by the movement of a cam follower arm 127 (see Figs. 16, 17) pivoted at 135 to the machine frame and having two follower points engageable respectively with cams 138, 138a rotatable by a manually operated knob 136. The movement of the arm 127 is transmitted to the member 74 by a link 78 one end of which embraces an adjustable pin 125 eccentrically mounted at the end of the arm 127. Needles shifting laterally (Figs. 1 and 2). The needle-bar gate 11 is pivoted to the sewing- machine frame at 12 and has an extension 10 pivotally connected at 9 to a fork ended lever 8 which embraces a cam 7 rotated by the arm shaft. 2. A block pivoted to a pin 14 on the lever engages a slot in a member 17 pivoted at the end of one arm of a bell crank lever 18 pivoted at 19 to the machine frame. The other arm of the lever is connected to a link 39 to which a rod 40 is adjustably connected by screws 42. Movement of the bell crank lever by the connecting rod 40 alters the stitch position. A bell crank lever 20 also pivoted about 19 has one arm pivoted to a link 27 adjustably connected to a rod 41 by screws 43, and has its other arm pivotally connected to the member 17. Movement of the rod 41 rotates the member 17 to alter the stitch width. The movement of rods 40, 41 are derived from the movements of pivoted cam followers which engage with cams 87 and 86 respectively. These cams are mounted, (see Fig. 5), on a hollow shaft 94 rotatable by a manipulator 99 to vary the stitch position. A cam 85 also mounted on the shaft 94 engages, in certain positions of the knob, with a resiliently constructed follower pivoted to the fixed member 47 and connected to one end of a link 82, the other end of which is connected to the eccentric pin 125 (see Fig. 3). The follower, connected to the rod 40, has two follower points which engage a cam 88 mounted on a shaft 96 concentric with the hollow shaft 94 and rotatable by a knob 103 to vary the stitch position. Buttonhole machines. To sew a buttonhole the manipulator 99 is turned so that the nose 101 (see Fig. 5) engages in a recess 106 in the knob 103 to cause the shafts 94 and 96, with their cams 85, 86, 87 and 88 to move together. The manipulator 99 is then moved successively into the positions A, B and C shown in Fig. 12. When it is in position A the cam 85 moves its resilient follower and the link 82 to move the follower point on the arm 127 (see Fig. 16) into contact with the cam 138 to provide reverse feed at the stitch length selected by the position of the knob 136. The flexibility of the follower accommodates the variation in the position of 127 as the position of the knob 136 is varied. The machine then sews along one edge of the buttonhole in reverse stitching. The manipulator 99 is then moved to a central position B which is marked by a notch. This moves the cams so that the machine produces barring stitches in the direction of forward stitching. In position C the cams are moved to produce forward stitching along the other edge of the buttonhole; and movement of the manipulator to B sews the second set of barring stitches again in a forward direction. A final movement to A sews an edge seam in reverse direction on the second set of barring stitches to lock them.