Patent GB-856574-A (GB)
Title: Improvements in or relating to yarn clamping and severing mechanism for knitting machines
IPC: D04B15/60
Filed: 1957-05-24
Abstract: 856,574. Knitting-machines. HANES HOSIERY MILLS CO. May 24, 1957 [June 13, 1956], No. 16523/57. Class 74 (2). In a circular knitting-machine, a yarn being withdrawn is clamped and cut close to the inner periphery of the needle circle; and, upon reintroduction, is looped about a fixed element within the needle circle by rotation of the needle cylinder and cut close to the first needle to take it, the thus severed loop being removed by means of air. A rotatable cutting wheel 8 is arranged underneath the welt transfer disc 5 in such a position that its cutting teeth sweep slightly outwardly beyond the edge of the disc into close proximity with the circles of needles 2, to shear the yarn against the edge 11 of a stationery cutting blade 12 recessed into the under side of the disc. The wheel is carried at the lower end of a shaft 9 driven by a pattern-chaincontrolled electric motor. When a yarn finger 4 is raised out of action, the yarn Y, as the cylinder continues to rotate, is directed downwardly by the upturned end of a fixed clamp 30, to pass over a restraining element 25 until caught beneath the clamp. As the yarn reaches the cutting wheel 8 and is severed, a clamp 32 is lowered to hold it. The yarn is thus cut close to the fabric. When a yarn is to be introduced, its finger 4 is lowered to lay the yarn across the needle circle to be taken by the first needle to reach it. As the cylinder rotates, the portion of the yarn, still held by the movable clamp 32, is withdrawn from beneath fixed clamp 30 and gradually dragged under the element 25, to be looped about it. Further rotation of the needle cylinder brings the yarn into the cutting wheel 8 to be severed, again close to the fabric. Immediately thereafter, the clamp 32 is raised to release the isolated end S of yarn which, by means of a jet of air blown through a tube 40, is sucked up a pendant branch 43 of the tube and deposited in a basket 41. The air may be supplied continuously, or only at the completion of each end severance. The cutting wheel may be driven by an air motor 15a, interposed in the air supply tube 40 and the exhaust from which provides the suction in the branch 43. In Fig. 13, the yarn is arrested by a lug 46 provided on the restraining element 25b, when drawn over that element during yarn withdrawal. As the yarn is re-introduced, its end, passing beneath the element 25b, enters between two turns of a helical spring formed into an endless belt 60 as the turns separate in passing round a pulley 55, is entrapped therebetween as it is cut, is carried up to a second pulley 58 where it is released as the turns again separate, and is blown by an air jet 61 into a basket 41b. In Fig. 17, a hook 80 sits in a slot 45c in the restraining member, with a hook closing slide 82 in the " open " position until a cut end of yarn is led into it. The main cam drum 98 thereupon opens a valve 95, supplying air to a jet 61c and to a cylinder 91. A lever 78 is thus rocked to raise the hook, the slide of which is closed, to trap the yarn end, by contact of a lug 83 which it bears with a spring finger 85. As the yarn end is brought opposite the jet, the slide is opened, to release the end, by contact of the tail of a lever 87 with a projection 89, and the end is blown into basket 41c. The drum 98 now closes the valve 95, the lever 78 is rocked back by a spring 99 to re-position the hook in the slot 45c and, as the lug 83 passes the spring finger 85, it is lifted by it to re-open the hook.