GB877182A - Yarn handling and severing mechanism for circular knitting machines and method - Google Patents

Abstract

877,182. Knitting-machines. BURLING- TON INDUSTRIES Inc. March 6, 1959 [March 14, 1958], No. 7919/59. Class 74 (2). A circular, rotary cylinder, independent needle machine, with a dial cap adjacent the top of the cylinder and at least two groups of individually retractable yarn fingers angularly separated in the direction of cylinder rotation and controlled by a timing drum, has common suction means for manipulating yarns from all the groups. The ends of yarns from inactive feeders are positioned in a passage 78 into which they have been drawn by suction induced in the passage by a flow of air through conduits 64, 66 in a yarn handling device 60, into which conduits the passage 78 leads. When yarns 34, 44 are to be substituted for yarns 28, 38 at main and auxiliary feeds 22, 24, respectively, the feeder 32 supplying yarn 34 is dropped into action and a valve is opened to supply air under pressure to conduit 64. The resultant suction and air flow tensions yarns 34, 44, ensuring positive yarn laps. Simultaneously, a piston 72 is elevated by the air pressure to raise an arm 74 against spring action from a clamp 90, so releasing those yarns extending therebelow. Simultaneously, or briefly thereafter, a shear blade 126 is raised, to open a yarn shear 120. Momentarily after introduction of yarn 34 the yarn 28 is withdrawn, a yarn-lap of about half-an-inch being provided. The yarn 34 has now been carried a short distance around the needle circle, the resultant slack being constantly taken up by the device 60. The yarn 44 is then introduced at or close to the needle which first took the yarn 34; the yarn 34 has, by now, been withdrawn from under a wire guide 110 and yarn 28 is positioned to take up its place. Yarn 38 is now withdrawn, to give a short overlap. As the needle cylinder continues to rotate, the withdrawn yarn 28 passes under guide 110 and around a guide post 114, passing with yarn 38 under clamp 90 and as these yarns come under passage 78, an element 116 separates them from the dial cap, to ensure that the suction on them is effective. Meanwhile, the ends of yarns 34, 44 are being withdrawn from the passage 78. An air blast from a nozzle 70 now bellies out the yarns where they extend inwardly from the needles, so to position them in the shear that the cut ends remaining on the fabric are of minimum length. The shear now closes over a time interval sufficient to allow all four yarns to be cut in a single stroke; and the cut ends from yarns 34 and 44 are picked up by the suction and exhausted through conduit 66. The cut ends of the withdrawn yarns 28, 38 are sucked up through passage 78 in place of yarns 34, 44. The air valve is then closed, after a slight delay, and the arm 74 again closes the clamp.