GB488855A - Improvements in or relating to sewing machines - Google Patents

Abstract

488,855. Sewing-machines. DEL-MAC SHOE PROCESS CORPORATION. Dec. 14, 1936, No. 34217. Convention date, Dec. 18, 1935. [Class 112] A chain-stitch machine for sewing an upper to the sole of a shoe while unsupported on a last comprises a fixed work support 100 and a movable support 102 both entering a stitchreceiving channel on the under side of the work, and a fixed rib 122 and a movable rib 128 on the presser foot entering a stitchreceiving groove on the upper side of the work opposite the channel on the under side. An awl 40 pierces the work, and a straight needle passes upwards through it, takes the thread from the looper 42, and then moves laterally towards the support 102 to feed the work. The needle bar 50 reciprocates in a guide block 52 secured to a rock shaft 54, by which the needle is oscillated in the line of feed of the work. A cast-off 38 is supported on a bar 70 reciprocating in the block 54. The movable support 102 moves with the needle in the line of feed and is rigid with the block 54. The presser foot 84 is held down by a leaf spring 88, and is lifted by a rock shaft 90 carrying a lifting lever 92 which operates through a self-adjusting locking device 96, 98, 99. The movable rib 128 on the presser foot is carried by a plate 124 pivoted on a vertical pin, so that it is moved aside during the feed movement of the needle. The presser foot lock comprises a spring-pressed pin 140, the end of which engages the top of a block 148 carried by the presser foot bar. The pin rests in a notch 168 in the block to permit the presser foot to yield slightly during the upward movement of the needle. During the feed movement of the needle, the pin 140 is disengaged from the block 148 by a cam lever 158 operated by a pin 162 on the lifting lever 92 when the latter is moved to lift the presser foot. The presser foot may be lifted by a treadle through a lever 172, which carries a plate 176 adapted to actuate the lever 158 for releasing the pin 140. A guard plate 190 covers the mechanism beneath the work, and serves as a guide for the sole to determine the angle at which the needle and awl pass through the work. A supporting horn 200 enters the interior of the shoe and is pivoted horizontally at 202 on an arm carried by a bracket 206 pivoted at 208, so that the horn is moved away from the work periodically to permit the feed movement of the work. A guard 230, 232 holds the shoe upper in advance of the sewing point against the shoulder of the insole to prevent it from being punched by the awl. The starting and stopping mechanism comprises a clutch 240 arranged to connect the pulley 46 to the crankshaft 44, and a brake shoe 244 engaging the hand wheel 242. These parts are controlled from a treadle by means of a clutch lever 246. In stopping the machine a two-armed lever 252 is forced by the lever 246 into engagement with a slot 258 in the hand wheel.