Patent GB-335846-A (GB)
Title: Automatic controlling device for sewing machines
IPC: D05B65/00
Filed: 1929-12-27
Abstract: 335,846. Fairweather, W., (Singer Manufacturing Co.). Dec. 27, 1929. Button-hole and eyelet-hole s e w i n gmachines. - Stop-motion device. A manually controlled device independent of the sewing- machine is provided for quickly and automatically actuating in their proper order and at their proper times, the work-clamp, the stopmotion device, the cutter and the under-thread pull-off and cutting device. The invention is described as applied to the straight button-hole type of machine described in Specification 4417/08. The stitch - forming mechanism comprises the reciprocating and laterally jogging needle 5 and oscillating looptaker 6, driven from the usual main shaft 7, the period of operation of which is controlled by the stop motion device 8. This device comprises a tilting stop-motion lever 8, pivoted at 9 and carrying a spring plunger 10 which, when shifted into its vertically upright position, Fig. 1, is within range of the stop-cam 11 on the gear 12 and is just depressed by the eccentric cam-portion 13, Fig. 4, to be projected upwards by the spring 14 into the stop-notch 15 of the cam 11. The gear 12 is rotated at half the speed of the main shaft 7 by the pinion 16. The main shaft carries fast and loose pulleys 17, 18 for the belt 19. The belt is embraced by the beltslipper 24 carried by the stop-motion arm 8. The arm 8 has an arm 25 connected to the stop-motion controlling rod 27 which carries a pivoted latch 28 having a tail 31. A spring 32 urges the latch in a clockwise direction. A spring 33 urges the rod 27 upwardly in a direction to swing the stop-motion lever into stopping position. Downward pull on the rod 27 tilts the lever 8 to shift the plungers 10 out of the notch 15 in the stop-cam and, at the same time, to shift the belt 19 on to the fast pulley 17 to start the sewing operation. Work-clamp.-This is of known construction, comprising the slide-plate 40 mounted in guides in the cross-slide plate 41 which slides in guides in the bed 1. The slides 40, 41 are actuated from the feed wheel 42, in the usual way. The tilting clamp foot 47 is mounted in a rock shaft 48 and has the usual needle-thread cutting and nipping blade. The shaft 48 carries a crane arm 50 to which is pivoted a rod 51 sliding in the bracket 52 on the lever 46. The sock shaft 39, operated by the stop-motion plunger 10 by the arm 35 and plunger 36, carries an arm 53 with a latch which causes the rod 51 to operate the needle thread cutter as described in Specification 4417/08. The rod 51 also carries a block 55 engaged by a lever-mechanism 56, 57, actuated by a cam on the feed shaft to cause the cutter to release and retrim the beginning end of the needle thread while the sewing operation is in progress. The clamp foot 47 is pressed downwards by the spring 60 and released by the pressure of a roller 61 on an extension 46<1> of the clamp lever. Under-thread cutting-mechanism.-The underthread cutting and nipping mechanism comprises cutting blades 67, 70 and nipper blades 68, 71. The under thread is carried into range of the cutters by an arm pivoted in the cross-slide plate 41. All these mechanisms are controlled by the pull-rod 27, which operate the stop-motion device and the lever 64 which operate the rack-clamp and under-thread cutter.