Abstract: In a chain-driven comb head for drawing frames, of the type including means for directing compressed air jets at the combs, these means comprise ducts for supplying compressed air to each needle field defined by the combs and slots for generating, from the supplied air, at least one flat jet of compressed air directed outwardly in a predetermined direction which does not intersect the zone of treatment of the sliver between the combs. During movement of the combs, the flat jet of compressed air flows successively over the surfaces of the combs to clean them. The needle-carrying bars making up the combs are rotatably mounted about their axes and have one end out of alignment, the head structure including at least two tracks engaged by the non-aligned ends and shaped so as to cause the combs to orient themselves in a predetermined direction when they pass in front of the flat jet.

Abstract: The invention concerns a needle bar draw frame or gill box with a needle field or gilling area of needle bars carried by chains. With the aim of attaining the usual performances in respect of speed and drawing ratio at the same quality also in the case of voluminous short-staple slivers with draw frames operating with an upper and a lower needle field, control means engaging from above into the needle field are used in a draw frame provided merely with a lower needle field. These control means are constructed as bristle-like holding down devices which are arranged particularly immediately upstream of a pair of drawing rollers and possibly shortly downstream of a pair of entry rollers, while the central region is controlled in the usual manner by a bar roller or bar chain.