Patent GB-919855-A (GB)
Title: Improvements in multiple yarn feed circular hosiery knitting machines
Inventor: MAHLER PETER AUGUST
IPC: D04B9/46
Filed: 1960-02-19
Abstract: 919,855. Knitting. SINGER-FIDELITY Inc. Feb. 19, 1960, No. 5909/60. Class 74 (2). At one feed of a two-feed rotating cylinder machine, needles of a selected group can be raised immediately adjacent to a yarn inserting and withdrawing point, to receive yarn, and be retained in a raised position as they leave the feed, so that the yarn lies across their outer faces, means exterior of the cylinder co-operating with the needles to support the yarn above the lower ends of their open latches and the remaining needles being raised to clear position before movement of the needles into the second feed where all needles are operated to take yarn and cast off their loops. The end of yarn at insertion or withdrawal is thus anchored in the fabric and the formation of a hole by reason of loop loosening is avoided. Yarn is fed constantly at feed A and change between single and double feed is effected by yarn insertion or withdrawal at feed B. The needle circle comprises groups E and F having butts of major and minor length respectively and groups C and D having butts of intermediate length, but there being among the needles of group D one needle 55, having a butt of minor length. At feed B, clearing and stitch cams 33, 44 are radially movable and cam 33 is made up of lower and upper radially offset parts 35, 36, and the cams can be retracted to a position in which the intermediate length butts of groups C and D will engage only the lower part 35 of cam 33 and will miss cam 34. Yarn withdrawal.-When yarn 45 from feed B is to be withdrawn, cams 33 and 34 are retracted, as above, before the group C needles move into the feed. Needles C are then raised by the lower part of cam 33 to a semi-elevated position, so that they clear the loops which they carry and follow a path 71, missing cams 34. The major butt needles preceding them have knitted normally. At their semi-elevated position, the group C needles receive the yarn 45 from feed B on their latches, Figs. 8 and 11, the yarn being held there by sinkers 52. The minor butt group following group C are unaffected by retracted cam 33, miss cam 34 and so retain their loops and leave the cams at the same elevation 73 as the major butt needles. At a point x between feed B and the point at which the end of yarn carried by the needles, having been clamped under a resilient finger 46, is cut by a shear 48, 49, the major and minor butt needles are cleared by jack cams 38, but the group C needles miss them. Normal clearing cam 31 has been retracted before group C needles pass into feed A, so as not to engage them, so that yarn 45 will remain on their latches, to be drawn down with the yarn now to be drawn at feed A as the group C needles pass under cam 32, to form composite loops 10, Fig. 5. Yarn introduction.-When yarn 45 is to be reintroduced at feed B, its finger 44 is depressed so that the yarn is introduced between the leading needle of group D and the trailing needle of group F; and cams 33, 34 are again retracted. The lower part of retracted cam 33 raises the group D needles to the path 71 to clear the loops of yarn drawn at feed A and cause yarn 45 to be received on their latches and be there supported by the sinkers, all except needle 55, which remains depressed. As the needles progress, the yarn is carried around a pin 56 to be held tightly across the fronts of the group D needles. Meanwhile, the leading needle 57 of group E has knitted a loop of yarn 45 through the loop previously drawn at feed A, to form the first loop of the restored dual feed. At x, needle 55 is raised by cams 38 and passes in front of the tightly stretched yarn 45 to hold it against the other needles of group D, so that it will be carried down with the new yarn taken at feed A, to form composite loops, as before, the yarn forming a float behind needle 55. In a modification, the cams 38 co-operate only with the jacks of the minor butt needles F, to raise these needles at x to track 89, the major butt needles being raised by the introduction of an auxiliary clearing cam to a track 90, at which level they clear the loops drawn at feed B, cam 31 having been retracted as before. The intermediate butts of group C are provided at 83 with notches which engage the part 35 of cam 33, so that the path which they follow is lowered slightly, to ensure that the lower ends of the needle latches are between the levels of the throats and the upper surfaces of the sinkers and that the yarn end which, during withdrawal, is drawn tightly against those upper surfaces, shall be positively positioned above the upper ends of the latches. Clamping and severing.-When the shear blade 49 is rocked to cutting position, a lever 63, pivoted on the same bolt 61, can rock under the influence of a spring 51 and by reason of a pin-and-slot connection 65, 66 between blade and lever, so that a block 64 on the lever presses on the finger 46, to augment the clamping pressure thereof. The tension of spring 51 may be adjusted to vary this pressure. Welt marking.-Cams 27, 28, or the auxiliary clearing cam, may be operated to form tuck stitches in the welt for size identification. The use of the arrangement is described in connection with the production of the stocking forming the subject of Specification 919,857, of even date.