a which comprises a base body 27 a and a steering member 36 in this embodiment the guide flanges 11 12 of the upper roller support and weighting arm 1 engage guide slots of a guide member 10 a of mounting bracket 7 a inserted into both sides of the upper roller support and weighting arm 1 are clearer rollers 31 32 with the end of their axles 33 34 the clearer rollers 31 32 are able to slide up and down in slotted guideways since the section in the illustration of fig4 extends through the slotted guideways the figure shows only the guide flanges 19 a and 21 a of the slotted guideways which are each oriented toward the free end of the upper roller support and weighting arm 1 with the other end of their axles 33 34 the clearer rollers 31 32 are inserted into a mounting support not shown for reasons of simplification which is arranged on each adjacent upper roller support and weighting arm with that each clearer roller 31 32 extends over respectively two yarn tracks the clearer rollers 31 32 lie under their own weight against the upper rollers 3 4 to secure the upper rollers 3 4 to the upper roller support and weighting arm 1 their axle 37 is manually inserted from the bottom into an elastic receptacle 35 of the steering member 36 in a likewise simple manner the axle 37 can again be removed from the receptacle 35 the steering member 36 consists of plastic and includes a pressure plate 38 at its upper end the pressure plate 38.