790,141. Knitting-machines. TEXTILE MACHINE WORKS. Aug. 12, 1955, No. 23249/55. Class 74 (2). A four-feeder circular machine for knitting patterned socks has patterning effected by a needle selection and yarn selection. Needle selection is made by providing several jack cvlinders beneath and coaxial with the needle cylinder, each jack cylinder containing the same number of frangible tooth butt jacks as there are needles. Selecting mechanism causes a jack or jacks to be selected at each feeder and cams transmit the effect of the jack selection to the corresponding needle or needles, to cause it or them to take yarn at that feeder. Yarn selection is made by providing a pin drum at each feeder which controls the yarn guides at that feeder. Diamond or Argyle pattern effects are produced by knitting a leg and foot by reciprocatory knitting and by feeding a yarn at each of the four feeders. Patterning mechanism for selecting jacks in each direction of movement of the needle cylinder is provided at each feeder and mechanism is also provided for ensuring that the yarns of adjoining patterned areas overlap about an end needle or needles to effect a suture formation as shown in Fig. 11. The machine described also includes a clutch for transmitting the drive from an electric motor, gearing for effecting continuous rotary and reciprocatory motion of the needle cylinder and jack cylinders and a clutch for changing the drive from one motion to the other as governed by a pattern drum, mechanism for rotating pattern drums and jack selector bit drums and pattern chain controlling mechanism therefor, thread guide and controlling mechanism for feeding rubber yarn, a bobbin support and yarn tensioning and controlling devices, yarn severing and clamping devices, stop-motions combined with the yarn tensioning and severing devices, and stich cam assemblies. Jack and needle cam system. Five jack cylinders J-1 ... J-5 are provided keyed on to a common sleeve 248 which is secured to the lower end of the needle cylinder 262, Figs. 15, 15A. Each jack cylinder is provided with adjusting screws s-1 ... s-5 for the purpose of aligning the tricks of each cylinder with the next and with the needle cylinder. The jack cylinders are of greater diameter than the needle cylinder and lifters H in the form of cranked members extend partly into the needle cylinder tricks to engage the lower end of the needles and partly into the first or master jack cylinder J-1 to enable the movement of the jacks to be transmitted to the needles. The lower end of each jack extends into the upper portion of the lower jack cylinder so that each jack abuts the end of the next and the effect of selecting and raising a jack in one of the lower four cylinders, therefore, being to raise the jack or jacks immediately above it. As can be seen from Fig. 87 the cam system for the lower jacks j-2 ... j-5 comprises a small lift cam on either side of each corresponding feeder, for example 629 and 629<SP>1</SP>, for jacks j-5 in jack cylinder J-5, positioned either side of feeder No. 1. The result of making a selection of a jack j-5 is to cause it to engage, for example, lift cam 629 and simultaneously raise all of the jacks j-4 to j-l-. The cam system at the level of the master jack cylinder J-1 provides high lift cams at each feeder, such as 625i and 625j at the feeder No. 1, and these cams are adapted to engage any selected master jack j-1 or one that has been raised by a lower jack and raise it and the corresponding lifter H and needle N to clearing height prior to the needle receiving yarn from the yarn guide at the feeder. Having raised the needles to clearing height the master jacks j-1 are immediately lowered by a cam 990, the action of which is to return the corresponding selected jacks j-5 to their original position ready for another selection. The needles meanwhile are engaged by a centre cam 1056 and lowered to yarn feeding height and subsequently lowered by stitch cam 1039 to knit yarn fed at the feeder. Stitch cams 1039 are provided at each side of the centre cam 1056 at each feeder to permit knitting in each direction of movement of the cylinder. The jack lowering cams 990 provided at each feeder are symmetrical and are mounted in a ring which is reciprocated in unison with the reciprocatory knitting to position the cams for operation in each direction of knitting. A guard cam 1036 is positioned beneath each stitch cam. The reverse stitch cam 1039b at the No. 1 feeder is also retractable. Beneath the centre cam 1056 at the No. 1 feeder is positioned a needle raising cam 1124 which engages a long butt on every alternate needle when it is raised to its operative position during the knitting of the stocking top in order that these needles may receive, without clearing their previous course loops, an elastic yarn at the No. 1 feeder. The elastic yarn is laid in the stocking top and extends between adjacent loops. The needle cam assembly at each feeder comprises a block 1022, Figs. 15, 94, secured to a support-plate 279 surrounding the machine. The block 1022 is radially adjustable and carries a second block 1030 which is vertically adjustable by means of an eccentric 1060. Secured to the block 1030 is a holder 1033 carrying the stitch cams 1039 and centre cam 1056 so that by rotating the eccentric the whole assembly can be adjusted to vary the stitch length. Slight adjustment of the height of the cams can be made by manual operation of a worm gear arrangement and automatic operation is controlled by a pattern drum through linkage during the operation of the machine. Each cam assembly is similarly operated from a separate pattern drum. The stitch cam 1039b at the No. 1 feeder is also operated through linkage from the pattern drum to be withdrawn at a desired moment. The needle cam 1124 for raising the alternate long butt needles during the feeding of elastic yarn at the No. 1 feeder is also controlled by linkage from a pattern drum on the machine. Needle jack selection. Two banks of pivoted selector bits 659 are provided for each jack cylinder in order to control the selection of needles at each feeder in each direction of knitting. Thus the selector jacks j-5 are controlled in their cylinder J-5 by bits 659 selected by pattern drums 633 on either side of the No. 1 feeder to control the needles during patterning of the leg of the sock, Fig. 74. The bits are further controlled by idler cams 668 which when operated by linkage from cam drum L-5, R-5 remove all the bits to an inactive position. Similar selecting mechanism is provided in association with the other jack cylinders to make selection at the appropriate feeders. In this connection the master jack cylinder J-1 has its jacks j-1 controlled by bits positioned either side of the No. 1 feeder and adapted to operate during the knitting of the heel and toe at this feeder. Jacks j-2 in jack cylinder J-2 are controlled by bits for selection at the No. 4 feeder and jacks j-3 and j-4 are similarly controlled at the No. 3 and No. 2 feeders respectively. After selection has been made of any of the jacks j-2--j-5 a presser member 760, Figs. 72, 72A, which may be rendered operative or inoperative by the cam drum, engages the selected jacks to tilt them such that their lower butt b engages the corresponding lift cam, for example jacks j-5 engage lift cam 629 at the No. 1 feeder, Fig. 87. Each pattern drum 633 for the jacks j-2 to j-5 is controlled by a cam drum, for example pattern drums for jacks j-5 are controlled by cam drums L - 5, R - 5. For this purpose the mechanism is similar in each case and comprises pawl-and-ratchet mechanism for rotating each drum which is actuated by linkage 964 engaging lugs 966 on a rotating shaft 176 to cause the pawl 679, Fig. 76, to rotate the ratchet 637 and drum 633. The pawl is held from engagement with the ratchet at desired intervals by a lever 675 controlled by the cam drum. A peg 677 is also attached to lever 675 and engages in a recess formed by the omission of the successive butts on the jacks. This peg acts as a timing member and renders the ratchet mechanism inoperative when it engages the recess. Further racking of the drum is therefore prevented until the peg is released by actuation of the cam drum. The pattern drums for the jacks j-1 are also similarly operated. The jacks j-1, however, are further controlled by upper and lower presser members 723a, 724a, Fig. 44, and upper and lower guard cams 702a, 703a, positioned in each quadrant of the machine and adapted to engage the upper and lower portions respectively of the jacksj-1. A lower guard cam 703a is provided preceding each of the four feeders, Fig. 87, and ensures that the jacks j-1 are maintained in their tricks. Upper guard cams are positioned only on either side of the No. 1 feeder and are operated from the cam drum during reciprocatory knitting of the heel and toe. The upper pressers 723a are provided to engage the selected jacks j-1 and serve to direct their butts b into engagement with the high lift cams such as 625i. The lower presser 724a is brought into operation when it is desired to perform continuous rotary knitting on all needles, the guard cams being withdrawn to enable the jacks j-1 to be tilted. The pressers 723a and 724a, are also controlled by linkage from the cam drums. During reciprocatory knitting for the formation of diamond patterns overlap of the yarns of adjoining areas about at least one needle is achieved by providing knockers 1144, Fig. 80, which engage the leading jack or jacks j-1 of a selected group and push its or their butt or butts b off the high lift cam such as 625i. At the height where the butt is pushed off the cam a small depression 625k is provided in the cam 625i to guide the butt past the cam, Fig. 87. The height is also such that the corresponding needle will receive yarn at the particular feeder but without it having cleared its previous loop. At the