GB276889A - Method of and means for tying weavers knots - Google Patents

Abstract

276,889. Marks, E. C. R., (Barber- Colman Co.). March 1, 1927. Knot - tying devices. - Weavers' knots are tied in yarns in the process of weaving by a device which forms two oppositely disposed interengaging loops about an anchoring element which is withdrawn as tension is placed on the threads. A loop a<1>, Fig. 19<a>, is formed in one thread with one strand crossed over the other and a temporary loop a<2> is formed in the crossed - over strand through which the second thread b is inserted, and is then drawn through the loop a<1> by drawing up the temporary loop. The apparatus is described as applied to a winder-tending mechanism employ in uniting the ends of the yarn masses being formed to the threads of reserve bobbins. The various knotting implements are actuated by cam-tracks formed on a drum 5. At the beginning of the operation the reserve thread a is guided into clamps 6, 7 and slack is provided therein by a take-up member 28 in the form of a hook. A hook 31, which is both rotatable and slidable, then moves across the strand and at the same time is rotated through 180‹, thus producing a loop a<1> with crossed strands. The knotting post 46, which is carried by a bell-crank lever having a yoke in which the post may be moved up or down by a lever, is now moved laterally against the loop, which is bent around it as shown in Fig. 14. The hook 31 then moves inwardly past the post to engage the crossed strand of the thread a, which to permit this is lifted rapidly by a finger 56 to the position shown in dotted lines in Fig. 15, the finger then descending again. The hook, having engaged the thread, is rotated through a further 180‹ to twist the strand, as shown in Fig. 17, and the hook is withdrawn, taking the strand to form a secondary loop a<2>, as shown in Fig. 18, and the hook is then reversely rotated 180‹ to remove the twist in the loop. At this point the end of the exhausted thread b is brought into the knotter by a moving arm and into engagement with a clamp 71, 72, 77, Fig. 20<c>, and a pull-off 86, and is engaged by a hook 63 sliding between a pair of plates 68, 69, of which the plate 69 is provided with a cutting edge which coacts with the hook to sever the end of the thread at the same time as it is clamped against the plate 68. The hook 63 draws the thread b through the loop a<2> and clamps it. Tension is then placed on the thread a held by the clamp 7 to draw the loop a<2>, and with it the thread b through the loop a<1>, thus forming the second permanent loop b<1>. Slack is provided in the thread b by the pull-off device and the hook 31 is released from the loop a<2> by a combined movement of the post 46 and a quarter turn of the hook 31, so that the loop b' is formed and encircles the crossed-over strand of the loop a', as shown in Fig. 20<a>. The knotter post 46 is now moved downward and the slack so produced is taken up by an inward movement of the serrated blade 9 of the upper clamp 6. The thread hook 31 is then moved first inward and then outward while being reversely turned into the position shown in Fig. 20<c>, in which it now engages the thread b, still held by the hook 63, and draws it taut. The hook 63 then moves to carry the thread into a recess and so release it. The clamps 71, 72, 77 holding the thread band the clamp 6 holding the thread a are also released, the clamp 6 being kept closed until the united threads have been thrust out of their guides by a forward movement of the knotter post. Final movements of the mechanism return the parts to their original positions.