which are arranged one above the other in pairs the thread guides 36 and 38 are designed as clips which can be attached from above and cooperate with either the upper guide bar or lower guide bar 32 34 for this purpose each thread guide 36 38 has a locking part 44 engaging in lock recesses 42 of the guide bar 32 34 and a bridge part 46 which bridges the other respective guide bar every thread guide 36 38 has a catch projection 48 at its back by means of which it engages in a locking groove 50 in the guide bar 32 34 so as to prevent unwanted detaching of the thread guide the head part 52 of the thread guides 36 38 also contains a guide 54 in the form of a guide eye to guide the fed thread 56 as will be seen particularly from fig2 thread guides 36 are connected with the lower guide bar 32 and thread guides 38 are connected with the upper guide bar 34 the thread guides of a group g 1 and g 2 respectively being guided along an offset line or racking line 58 60 in each instance the guide bars 32 34 of each group g 1 to g 7 have a flat construction and are supported by one another to this end the lower guide bar 32 contains a cross piece or web 62 which projects upward in the principle plane of the guide bar and engages in a corresponding groove 64 of the adjacent guide bar 34 the guide bars which move back and forth in their longitudinal direction are supported at their respective ends in a bearing block 66 in order to place the thread 28 56 in.