Patent GB-989187-A (GB)
Title: Improvements in and relating to a method of and apparatus for knitting in circular knitting machines
IPC: D04B9/18
Filed: 1962-01-29
Abstract: 989,187. Knitting. M. NEBEL, and E. NEBEL. Jan. 29, 1962 [Feb. 18, 1961; March 14,1961; June 10,1961; Aug. 8, 1961], No.3360/62. Heading D1C. Ladder resistant fabric, e.g. as shown in Fig. 1 of Specification 989,186 is knitted on a circular knitting machine with latch needles, sinkers and two or more feeder systems by forming a short thread length course (b) of small stitches at one feeder system and at the succeeding system forming a long thread length course (a) of larger stitches and tuck loops, the latter forming tuck stitches with the corresponding small stitches of the previous course so that these small stitches in the course which are contracted into small locking stitches, the needle motions being interchanged after at least every two such courses so that locking stitches appear in successive wales in successive short thread length courses. The machine may be a two or four feeder machine or, to knit the tuck stitch fabric in Fig. 3 of Specification 989,186 a three feeder machine. As shown, the difference in height between the levels Pa and Pt of sinker P, Fig. 1, represents the difference between the loop lengths of the stitches in courses (a) and (b) which are drawn on these two levels. The sinkers may be operated as described in Specifications 925,462 and 925,463. The sinkers are withdrawn after the formation of course (b) so that the sinker loops are in front of the sinker hooks and are reinserted when knitting course (a) and further inserted when knitting course (b). During the formation of course (a) the tuck loops are drawn on the sinkers and the sinker loops of course (b) are drawn on the sinkers for a second time the stitches associated with the tuck loops being extended at the expense of the other stitches in the course which form locking stitches. As shown, Fig. 3, courses (b) and (a) may be drawn on levels Pd and Pa of sinker P1 respectively in front of and behind the sinker hook Pe or alternatively on levels Pk and Pd respectively. In a modification, Fig. 5, (not shown) in sinker P, Fig. 1, level Pt may be below level Pd . Alternatively, or in addition, an adjustable knitting cam may be provided. As shown, knitting and counter cams 1, 1a are carried on a slide 2 mounted in a guide 3 and displaceable by a lever 10 radially towards the cylinder 11 to engage the needle butts. Guide 3 is pivoted on a shaft 4 which carries a lever 5 adjustably connected by a screw 14 to a lever 6 carrying a roller 7 which engages a control cam 8 on a link 9. Link 9 is operated to move cam 8 by the cam which raises and lowers the needle cylinder to vary the overall size of the stitches. The adjustable needle cam may be adjustable to the same level as that at the other feed so that stitches of the same size are produced in all courses e.g. for the welt. When using an adjustable knitting cam, sinkers may be used having only one sinking point behind the sinker hook for both courses and it may lie higher than that in front of the sinker hook which latter may have an extension Px, Fig. 6.