GB1332580A - Sewing machines - Google Patents

Abstract

1332580 Zig-zag chainstitch sewing machines VIRGINIO RIMOLDI & C SPA 27 Oct 1971 [13 Nov 1970] 49922/71 Heading DIG In a zig-zag two thread chainstitch sewing machine, a spreader member 45, movable in the direction of arrows C and D (Fig. 2), holds back the needle thread loop 79 (Figs. 4, 7) to facilitate entry of the needle into the triangle formed by the looper 21, the looper thread 77 and the needle thread loop 79. The drive to the spreader 45 which is fixed to a shaft 60, is from the main drive shaft 4 via a cam 71 and members 72 73, 74 and 75 (for axial movement in direction D) and via a cam 70 and members 42 and 43 (for rotational movement in direction C). The drive to the looper 21, which is fixed to shaft 37, is via a cam 48 and members 49, 50, 51 and 52 to a sliding engagement between the fork 54 and block 55, and thence via levers 57 and 58 for rotational movement in direction B). Axial movement A comes via a cam 30 and pitman 31 (Fig. 1) and levers 32, 33 and 34. The needle drive from an upper shaft 12 is via a crank 25 and connecting rod 26. The zig-zag movement between needle positions I and II is obtained from shaft 12 via gears 14 and 14a, and a cam 15 embraced by a forked lever 16. The fork is firmly attached to a lever 18, and both pivot about an axis 17, so causing a longitudinal movement in link 19 and hence shaft 91. The width of the zig-zag is variable by moving the end of link 19 along the slot in the lever 18.