Patent GB-190710693-A (GB)
Title: Machine for Forming Knotted Thread Fastenings.
Inventor: FAIRWEATHER WALLACE
Filed: 1907-05-08
Granted: 1907-11-28
Abstract: 10,693. Fairweather, W., [Singer Manufacturing Co.]. May 8. Knotted - stitch machines; presser-feet; threadcutters; governing needle thread; needle-bars, vibrating laterally; tying or knotting.-Relates to a machine for attaching buttons or for uniting separate articles by means of a knotted thread, as shown in Fig. 42<a>. The knotting-mechanism is arranged below the work to co-opetate with a laterally vibrating needle of the usual kind. It comprises two pairs of nippers 71, 72 which are mounted on a holder 73, which itself is pivoted and rocked by a cam 89 and a lever 92 to move the nippers in a plane at right-angles to themselves. Each pair of nippers comprises a main arm 71 or 72, carried by the holder, and an arm 74 or 75, hinged to it. The arms 74, 75, have tail-pieces which pass on opposite sides of a pin 97 on a cam-actuated rod 95, so that a movement of the rod will close one pair and open the other. The nippers are oscillated about their pivot 73 by levers 78, 79, which are mounted upon a fixed pivot 80, are actuated by cam-grooves in a disk 87, and engage the nippers by means of projections 81, 82, which pass through slots in the arms 71, 72. The cam which actuates the needle-bar frame is shaped to cause the needle to make one descent in one position, and two descents after being moved laterally. In the knotting-operation, the forked nippers 71 seize the thread and hold it while the needle rises from the work and enters it again after being vibrated laterally so as, for example, to enter the second hole of 'a button. The nippers 71 are moved around the needle and pass the thread end through the new needle loop. The jaws of the nippers 72 are passed into the slot of the nippers 71, Fig. 36<a>, and simultaneously the nippers 71 are opened and the nippers 72 closed so that the thread is transferred from one to the other. The nippers 72 hold the thread until the needle again descends in the same place ; the thread is then transferred to the nippers 71 and passed through the second thread loop to form a second halfhitch as before. The thread is cut at the end of the knotting operation by a knife 31, mounted in guides on the presser-foot, which co-operates with the sharpened edge of the needle slot in the foot. The knife is reciprocated by a lever 32 and a camactuated lever 36, a bowl on the end of which enters a cam-slot in the lever 32. The upper arm of the lever 36 forms one element of a device for measuring off the thread for the next operation the thread being passed through a fixed eye 51 and an eye 49 in a lever 50 on either side of the eye in the lever 36. The slot 35 comprises an upper portion concentric with the pivot 37 and an eccentric portion, in order that when the lever 36 is actuated the bowl moves in the concentric portion first and measures off the thread only and subsequently enters the eccentric portion and actuates the cutter. As the thread-cutter is mounted on the presser, it cuts the thread long or short according to the thickness of the work, and to compensate for this the lever 50 which carries one of the eyes of the thread measurer bears against a shaped block on the presser bar and is moved in or out according to the thickness of the work. The thread is clamped during the final descent of the needle by a simple clamp 62, one member of which is actuated by a cam. The knotting-mechanism may be variously applied, for example, to tie the ends of a lace in a machine for lacing shoe uppers preparatory to lasting.