guiding roller 3b is illustrated with a dash dotted line however without illustrating the tension feeler associated therewith the thread f is supplied from a source such as a bobbin through an inlet eyelet 32 to the thread guiding roller 3 the thread after passing through eyelet 32 then passes through the eyelets 13 so as to partially wrap around the roller 3 this thread is presently being processed on the knitting machine it thus has a withdrawal tension which holds the tension feeler 5 against the force of the return spring 25 as illustrated the thread eyelet 21 is in this position on the swivel arm 18 between a first stationary guide eyelet 33 and a second stationary guide eyelet 34 the stationary guide eyelets for the threads f a and f b are arranged there behind in the described position of the tension feeler 5 its contact piece 22 rests on the contact 27 and closes the circuit for the electromagnet 17 same attracts the arm 14 against the force of the spring 15 and thus holds the swivel arms 10 of the thread guiding element 9 in a position in which the two eyelets 13 are disposed on substantially diametrically opposite sides of the thread guiding roller 3 at the level of the area around which the delivery belt 8 is looped the thread f is thus moved by the delivery belt 8 and.