Patent GB-190317998-A (GB)
Title: Improvements in Sewing Machines
Inventor: FAIRWEATHER WALLACE
Filed: 1903-08-20
Granted: 1903-11-26
Abstract: 17,998. Fairweather, W., [Singer Manufacturing Co.]. Aug. 20 Sewing - machine thread - cutters and thread-end holders ; button-attaching machines ; buttonholesewing machines.- Relates more particularly to automatic thread - cut - ting mechanism, whereby the thread is severed after a predetermined number of stitches, as in sewing on buttons, forming bars or tacks, &c. Figs. 2 and 3 show the application to a button-attaching machine provided with an automatic button-feed m, such as is described in Specification No. 30,183, A.D. 1897. The cutter consists of a movable blade 16, Figs. 8 and 9, which works in conjunction with a fixed blade 17, fixed to the base of the boss 13 on the presser-foot 12. The blade 16 is carried by the spindle 15, which is mounted in the boss 13, and connected by the arm 18 to the spring-actuated operating-rod 19, Fig. 2. The upper edge of the blade 16 is rounded &c., and acts in conjunction with the boss 13 to grip and hold the thread after the cutting operation, until the machine has again been started and one or more fastening stitches have been inserted in the work. While the machine is running, the cutter is held open by the finger 31, Figs. 2 and 3, on the lever 30 engaging between the collars 20, 21 on the rod 19. The spring 24 on the rod 19 is engaged by the end of the lever 25, which, actuated by the cam 27, serves also to operate the button-feed. The cam 27 is rotated with an intermittent motion, by means of the lever-dog 41<a>. The lever 30 carries a second lever 34, 35, Fig. 3, through the upper end of which passes a spring-controlled rod 36 connected to the stop-motion lever 41. At the proper time, the rod 36 brings the tappet 44 on the lever 35 into the path of the sliding-block 43 connected to the dog 41<a>, so that the finger 31 is disengaged from the collar 20, and the rod 19 is then moved rearwardly by the spring 24 to operate the cutter. Governing needle thread.-Prior to the cutting operation, the lever 34 acts on the tension discs 75 and slackens the tension, so that the blade 16 can draw out sufficient thread to obtain and retain an effective grip on the thread after the latter has been cut. Presser lifted automatically; stopping-gear.-The bar 62, Fig. 2, of the presser-foot has a hooked engagement with the lever 61, which is normally held in inoperative position by the lever 69 engaging under the lug 70 on the lever. The lever 61 has also a spring-connection 64 with the lever 65, which carries a spring catch 66 adapted to engage with the collar 57 on the spring plunger 55 mounted on the stop-lever 41. The driving-shaft 45 is pivoted with fast and loose pulleys 47, 46, and a cam 37, Figs. 5 and 6, is loosely mounted on a sleeve on the pulley 47, to which it is operatively connected by a pin 53 passing through a slot in the pulley and connected to a block 52, which is engaged on opposite sides by two coiled springs 50 of unequal strength. In operation, the cam 37 depresses the plunger 55 until the collar 57 engages under the catch 66, so that, when the recess 49 in the cam allows the plunger to rise, the lever 65 is moved to put the spring 64 under compression. When the bar 19 is actuated to operate the cutter, it disengages the catch-lever 69 from the lug 70, and the lever 61 is then operated by the spring 64 to raise the presser and release the work.