Patent GB-332824-A (GB)
Title: Improvements in thread-knotting devices
IPC: D03J1/16
Filed: 1929-10-04
Abstract: 332,824. Zehnder & Sons, Ltd., J., (Assignees of Bischof, U.). Oct. 4, 1928, [Convention date]. Knot - tying devices.- In a warp-thread knotting machine, the knotting bill comprises a rotatable sleeve with a spanner-like jaw and an axially movable rod sliding in the sleeve and carrying the other spannerlike jaw, two springs of differing strengths urging the jaws together so as to nip the threads securely during tying and braking. Then lightly alter completion of the knotting. The knotting carriage 8 has rollers 9 running on rails 6, 7 and is driven from a shaft 11 through gears 14, 15. The to-and-fro rotation is obtained by a clutch and a two armed lever 22 engaging a groove in the clutch. A toothed wheel 33 at one end of a shaft 20, engages a rack 32 on the side frame. At the other end of the shaft is a toothed wheel 36 engaging a rack 35. Pawl levers 37, 38 are loosely mounted on the shaft 20 and engage second sets of teeth in the wheels 33, 36. Rollers 41, 42 of the panel levers engage the same cam groove in the disc 45 and carry tension rods 48, 51 secured to a shaft 46 governing an oscillating lever 50. Oscillatory keys 52, 53 bear on the warp threads and take up a variable position during tying so that projections 55, 56 on the keys are at times clear of the levers 49, 50, allowing the knotting carriage to be moved relatively to the warp and also displacing the warp carriage. Grippers 57, 58 of known form are provided. A knotting bill 157 attached to a sleeve 159 having teeth 158, is journaled in the knotting carriage. A rod penetrating the sleeve carries a jaw 157<1>. The jaws are urged together by springs 161 and 163. Rotation of the bill is effected by a rack 164. A lever 171 pivoted at 144 carries a roller engaging a cam groove in the disc 153. The rack 164 carries a pin 167 engaging the forked end of one arm of a lever 169, the other arm engaging a cam groove in the disc 170. The bill is rotated and its jaws opened and closed by the rotation of the discs 170, 153. A hook needle 148 is moved upwardly relatively to the threads 76<1>, 78<1>, Fig. 14, from the warp, so that the point guides the threads to lie between the hook and the rod 149, which presses the thread 76<1> upwards. The hook seizes the second thread and draws it down against the first thread, when both are then gripped firmly by the rod 149 and the hook neck. The hook needle 172<1> then moves upwardly and secures the warp threads in its hook. The shear knife 126 moves down and a knife 136 moves upwards to cut off the threads, after which they move apart again, The two needles then pull the gripped threads into horizontal position to the rear of the bill, which turns through three quarters of a revolution. The needle 172<1> pulls the threads forwards through 90‹ to engage under the bill, which turns another 180‹, the needle 148 executing an oscillatory movement towards the bill, thereby looping the thread round the neck of the bill. The jaws then open to grip the threads and the needle 148 releases the threads. The bill makes a third of a backward revolution to form the knot and the needle 172<1> oscillates outwards to pull the loop over the bill to complete the knot. As soon as the loop has been pulled over the bill, the bush 162 is pushed upwards by the lever 171 so that the stronger spring 163 is brought out of operation on the jaws, leaving the washer spring 161 to supply the necessary tension. Fig. 33 shows the completed weavers' knot.