GB174440A - Improvements in or relating to sewing machines - Google Patents

Abstract

174,440. British United Shoe Machinery Co., Ltd., (United Shoe Machinery Corporation). Oct. 26, 1920. Sewing - machines; Thread-cutters and thread-end holders.- In a shoe or heavy leather wax-thread sewing - machine, thread cutters and thread-end holders are provided for both needle and shuttle threads. The devices are actuated when a continuously reciprocating lever 76 is coupled to a lever 70 on a shaft 66 by the action of raising the presser. The lever 70 carries a pin 80 normally withdrawn by a spring and when the presser is raised a plate 92 on the presser lifter 94 engages the pin and moves it into a hole in the lever 70. The pin is retained in that position by a locking-pin 86 until the latter is pushed outwards by a cam-surface. The needle-thread cutter and holder comprises a bifurcated rod 24, Fig. 10, sliding in a sleeve 26, mounted in a guideway in the work support 14 and actuated by a rack and pinion 52 and other linkages 54, 58, 64 from the shaft 66. A pin 30 projecting from the rod 24 slides in a slot in the guideway of the sleeve and limits the movement of the rod. A thread-cutting edge 34 is formed on the sleeve. When the sleeve is first moved upwardly, the rod and sleeve move together and the bifurcated end of the rod moves to embrace the thread. Then the pin 30 prevents further movement of the rod and the sleeve in moving over it, closes the bifurcated end causing it to grip the thread which is then cut by the edge 34. The shuttle-thread cutter and holder 38 is similar, but the cutting-edge is formed on one arm of the bifurcated rod. The pin 80 carried by the lever 76 engages the lever 70 when the lever is at the low part of the cam. The machine is then stopped, coming to rest with the lever 76 at 96. On restarting, the lever passes into a concentric poition of the cam and, just prior to the completion of one revolution, enters the forepart of the cam and at that time a high part on the periphery of the cam ejects the locking- pin 86. In this way, the threads are engaged and cut and the threadholders partly withdrawn again for the first revolution in the next operation and the threadends are held until after the setting of the first stitch. The invention is shown as applied to machines of the type described in Specifications 23478/10 and 1021/14.