GB191515049A - Stitch-forming Mechanism for Sewing Machines. - Google Patents

Abstract

15,049. Fairweather, W., [Singer Manufacturing Co.]. Oct. 25. Button-hole and eyelet-hole sewing - machines; loop stitching. - The straight upper needle 37, Fig. 10, passes through the material and forms a loop which is seized by a luoper 73 and carried into the path of the curved lower needle 85. This needle passes through the loop of the upper-needle thread and through the button-hole and throws out a loop through which the upper needle passes. The main shaft 6, Fig. 1, drives an upper shaft 10 by means of connecting-rods 8, and the shaft 10 drives a shaft 23 at double speed through a trammel 18, 21. A crank on the shaft 23 drives the needle-bar 30 by a connecting-rod 26 attached, at one side of the axis of the needle-bar, as shown also in Fig. 3, to a revoluble collar 28 on the needle-bar. A shaft 42 for operating the lower needle and the luoper is driven through two-speed gearing 40, 41 by the shaft 6. A crank 43, Fig. 3, on the shaft 42 is connected by a link 45 to one member 47 of a toggle, the other member 50 of which is pivoted to the head of a rod 53 sliding in a bearing 54. The forked held 52<1>, Fig. 1, of the rod 53 engages a groove in the hollow sliding rod 56, which operates the lower needle and the looper. The head 52<1> also carries a finger 102, Fig. 3, which descends between the arms of a forked thread-guide 98 and pulls each stitch tight, at the same time pulling off thread for another stitch from the tension device 97. An arm 107, Fig. 1, operated by a cam 105 pulls the upper thread from the tension device 109. The head 57 of the rod 56 is formed as a nut to operate a spiral-tooth wheel 67, shown also in Fig. 9, carried by a spindle mounted in bearings on the turret 59. A crank 68 on this spindle is pivoted at 69 to a plate 70, which carries the looper 73, the plate being also pivoted at 75 to an arm 76 turning on a pivot 78. The lower needle 85, Figs. 9 and 10, is secured in a clamp 83 at the end of an arm 82 pivoted in an inclined bearing 80. An intermediate point in the arm 82 is connected by ball joints and a link 87 to the head 57, as shown in Fig. 1. The needle-plate 94, Fig. 9, is carried by an arm 92, which is adapted to be tilted on its pivot 90 during the button-hole cutting operation. The sliding work-plate 151, Fig. 1, with the work clamps 152 is operated through swinging levers from cam-grooves in the upper surface of the feedwheel 141. The button-hole cutters are carried by levers 158, 159 operated by a spindle 161 driven by a belt-wheel 162. The needle-bar and the turret 59 are rotated in unison from a shaft 125 arranged at one side of the levers 158, 159 and carrying cranks 127, 128, connected through adjustable links 130, 132, 131 and 135,137, 136 to the arms of bell-cranks 112, 120 carrying toothed sectors 115, 121, which gear with pinions 38, 63 mounted respectively on the needle-bar bushing and on the boss of the turret. A cam on the shaft 161 operates a lever on the pivot of the stop-lever 15 to permit the starting of the stitching-mechanism when the button-hole has been cut. Specifications 9458/12, 9842/13, and 100,990 are referred to.