from there to the fixed eyelet 16 to terminate through the outlet eyelet 20 of the arm 17 and continue towards the needles 54 as may be seen from fig1 when an arm 17 is activated it pivots towards the support 12 of the eyelets 16 shortening the lengths formed successively between the ring 19 and the eyelets 16 and 20 when the arm 17 is in a rest position the amount of yarn 14 fed in excess to the needles never exceeds the amount that may be stored between the ring 19 the eyelet 16 and the terminal eyelet 20 so that at any one time the feeder tensions the yarn with a constant tension irrespective of whether the yarn is being fed or not in other words the striper 53 selects one of the yarns 14 shown as 14a in fig1 and which is therefore the yarn which will be knit the remaining yarns such as 14b in fig1 are not knit since they have not been selected the needle 54 draws the yarn 14a whereby the needle is fed at the expense of the loop of yarn comprised between the eyelet 20 the fixed eyelet 16 and the ring 19 of the same arm 17 as the yarn from this loop is consumed the arm 17 pivots downwardly about its axis thereby the part of the arm terminating with the eyelet 18 moves out of the position located at the height of the operating space 29 and rises up to the height of the cylindrical portion 6a of the corresponding roller 6 consequently the portion of yarn lying between the eyelet 18 of the arm 17 and.