Patent GB-1098891-A (GB)
Title: Circular knitting machine
IPC: D04B9/56
Filed: 1965-05-05
Abstract: 1,098,891. Knitting. SINGER CO. May 5, 1965 [May 6, 1964], No. 18911/65. Headings D1C and D1K. The heel of a stocking is shaped-as it is produced on a circular machine during continuous rotary motion of the needle cylinder by incorporatig additional courses in the heel portion compared with the instep. In a four feeder machine the needles are divided into an instep group having shont butt needles 16a, Fig. 12, a heel group having long butt needles 16c and a series of needles 16b dispersed between the heel and instep needles and having butts of an intermediate length and which needles serve to secure the ends of ingoing and outgoing yarns by forming tuck stitches, as illustrated in Fig. 22. During continuous rotary knitting of the heel all the, needles are raised and knit a main yarn from a feeder 45a, 47, Fig. 9, at alternate feeding stations 45, 47 and the heel and intermediate needles are raised to an additional height to take a reinforcing yarn from a second feeder 45b, 47b. At the intermediate feeding stations 46, 48 only the heel and intermediate needles take a main and a reniforcing ,yarn 46a, 46b and 48a, 48b and whereas the heel needles 16c knit the yarns the intermediate needles tuck them. To achieve this a cam set 56a, 58a is provided at each station 56, 58 and comprises a block having a clearing cam surface 61, Figs. 9 and 11b, which is interrupted by a gap 62 providing access to a groove 63 through which the butts of the short butt and medium butt length needles can pass if a cam slide 64 covering the gap 62 is withdrawn. Likewise, a cam slide 66, Fig. 11a, is provided which interrupts the groove 63 and serves to elevate the medium butt needles to tuck height. Consequently at the feeding stations 46, 48 during the knitting of the leg of the stocking the cam slide 64 is projected inwardly and in combination with cam surface 61 elevates all of the needles so that in combination with the other feeding stations the machine knits on all needles at each station during each revolution of the cylinder. When the heel is commenced, however, the cam slide 64 is withdrawn so that it only engages the long butts of the heel needles and the cam slide 66 is positioned to engage only the medium butt needles, with the result that during continuous rotary motion of the cylinder all of the needles knit at the alternate feeding stations 45, 47 but at the intermediate stations 46, 48 the long butt needles knit and the intermediate butt needles tuck whereas the short butt instep needles miss yarn altogether. The effect is to produce a pouch in which double the number of courses are incorporated compared with the instep. The heel and intermediate needles are elevated to take yarn at the alternate stations by the provision of jacks having long butts 29a and which are raised by a selector cam being projected to engage them at the stations 45; 47. The reinforcing effect can be varied by increasing and subsequently decreasing the number of instep needles raised to an elevated position to take a reinforcing yarn at each of the alternate stations 45, 47. This is relieved by the provision of jacks beneath these needles having butts 29a, 29b and 29c of gradually diminishing length which are engaged in turn to elevate the corresponding needles as the corresponding selector cams 201, 202, 203, 211, 212, 213 are gradually introduced. The gradual introduction of the selector cams to cause elevation of the needles to take a reinforcing yarn at the feeding stations 45, 47 is controlled by a form of stepped cams periodically rotated by pawl and ratchet mechanism driven from an eccentric on the machine. There is an overriding control which renders the pawl and ratchet mechanism stationary if it is desired to cease further selection at any one stage. In addition the ingoing and outgoing heel yarns are introduced and withdrawn by simultaneously actuating the main and reinforcing yarn guides into and out of an operative position. This is achieved by the provision, at each of the two intermediate stations 46, 48 of a bell crank lever 115 having a pin 116, Fig. 4, which engages beneath the two yarn guides 48a, 4%b. This lever 115 is adapted to be actuated by a further lever 118, controlled, each revolution, by a cam 111 on the sinker dial 20, Fig. 7. A further lever 122 controlled from a control drum permits the operation of the lever 118 so that during the knitting of the heel the yarns at the stations 46, 48 are introduced and withdrawn. The withdrawal of the yarn guides causes the yarns to extend above the welt dial of the machine where it is guided and clamped on the top of the dial and thereafter severed. A pneumatic nozzle also serves to hold the yarn. To enable yarns,of different characteristics to be knitted in alternate courses throughout the leg and instep, the yarn guides at one of the two stations 45, 47 are changed during heel knitting so as to feed yarns and revert to feeding the same kind of yarn on completion of the heel.