to the needle bar 59 and which also carries the thread raiser 44 projecting outwards through a slot in casing 26 the loop forming mechanism 61 arranged in base part 12 and which will be described relative to fig3 to 6 is driven by the crank pin 55 via connecting rod 62 via a drive lever 63 it oscillates a shaft 64 to which are fitted in non rotary manner a yarn gripper 65 and an operating lever 68 the yarn gripper 65 has an arcuate or ring segmental shape in its outer portion which carries a yarn eyelet 69 close to its front end and is connected via a radial arm to shaft 64 an overcast gripper 66 is pivotably mounted about a shaft 70 and is driven by lever 63 via a thrust rod 71 it has an arcuate shape and to its one end is fixed the shaft 70 whilst the other end is provided with a gripper fork 150 a retaining gripper 67 with a retaining finger 151 is pivotable at its front end about a shaft 72 and is driven by lever 68 via a lever arm 73 a stop lever 74 cooperates with a casing stop 75 against which it is pressed under the tension of a spring 76 for limiting the movement of the retaining gripper 67 the conveying means 52 for the material 80 to be looped or linked fig9 contain a conveying serrated slat 81.