Abstract: An exchangeable reinforcing element for pressure rollers of drafting units of spinning machines. The reinforcing element comprises a thin reinforcing tube and a flexible roller covering securely affixed thereto which can be slid onto the pressure roller base body. The reinforcing element is cut from a long tube body to the required effective width. The roller covering is turned down at both ends in such a way that the reinforcing tube projects laterally over the roller covering.

Abstract: A holding device for a twin pressure roller of a drafting unit includes a number of bottom rollers. The twin pressure roller includes a stationary axle and two rotatably supported upper rollers. The holding device includes at least one positioning element assigned to the axle of the twin pressure roller and at least one force transmission element, wherein the positioning element is arranged in the area of the center of the axle of the twin pressure roller and thus permits the twin pressure roller to move in a pendulum fashion around the center. The holding device, together with the twin pressure roller may be lifted from the bottom roller. At least one catch bearing for approximate positioning during placement on the bottom rollers is assigned to the twin pressure roller. It may further be provided that the force transmission element is arranged separately from the positioning element and that the catch bearing is integrated into the force transmission element.

Abstract: A twin unit has two drafting devices for drafting fiber strands and is applicable in a spinning machine. The twin unit includes a common housing for the two drivable drafting devices, whereby the housing is detachably mounted in a machine frame. The drafting devices include a number of drivable bottom rollers and are arranged essentially mirror-symmetrical to one another. Each bottom roller has an area which drafts the fiber strand and is characterized in that the bottom roller has two bearing points. The two bearing points of each bottom roller are arranged one on either side of the area which drafts the fiber strand. In one variation, at least two opposite bottom rollers may form a bottom roller pair, in which the bearing points facing to the plane of symmetry of the twin unit are taken up in a joint bearing take-up. In addition, a top roller in the form of a twin pressure roller may be assigned to a bottom roller pair.