Abstract: In a spinning rotor for an open end spinning unit, the rotor being provided with a bore extending along its axis of rotation to accommodate a yarn extraction tube and being formed to define a fiber collection trough and an intake portion whose cross section widens in the direction toward the trough, the intake portion presenting a radially outwardly extending projecting portion which merges into and defines one boundary of the fiber collecting trough, the region where the projecting portion merges with the trough constituting the region of maximum diameter of the trough and the side of the trough opposite the projecting portion being defined by the spinning rotor bottom surface, the accumulation of dirt in the fiber collection trough is prevented by forming the collection trough so that the radially outermost end of the surface of the projecting portion defines the maximum diameter of the trough, imparting to the portion of the trough adjacent the rotor bottom surface a configuration such that the diameter of

Abstract: In an open-end spinning unit having a spinning rotor presenting an entrance opening, a break-up roller mounted for rotation coaxially with the spinning rotor and having a frontal end section at the end thereof directed toward the spinning rotor, the frontal end section being generally enclosed by the portion of the spinning rotor defining its entrance opening, and a housing enclosing at least part of the break-up roller, there is further provided, in order to improve the guidance of fibers into the fiber collecting trough of the spinning rotor, a fiber collecting ring located between, and coaxial with, the spinning rotor and the break-up roller, and supported by the housing, the fiber collecting ring protruding axially, in the direction away from the spinning rotor, beyond the frontal end section of the break-up roller and, in the direction toward the spinning rotor, beyond the entrance opening of the spinning rotor, with the inner surface of the fiber collecting ring facing the break-up roller and serving at

Abstract: In an open-end spinning unit for producing yarn from fiber material, the unit including a spinning rotor having a circumferential portion extending axially from one axial end face of the rotor to enclose a space in which such yarn is formed and which defines a fiber collection trough, and a fiber guide disc rotatably mounted coaxially of the rotor and having at least a portion disposed within such space, the guide disc is free of physical connection to any drive system and is mounted to be freely rotatable, and the unit further includes a force transmitting arrangement operatively connected between the rotor and the disc for causing the rotation of the rotor to induce rotation of the disc without physical contact between the rotor and the disc.

Abstract: An open-end spinning machine system containing a plurality of spinning units, the components of each unit including a spinning turbine, a breakup roller, a feed roller, a yarn extraction device and yarn wiping apparatus, is controlled during stopping and subsequent restarting by an automatic control system which is operated by switching members in such a manner that, during stopping of the system, the turbine, feed roller, yarn extraction device and winding device of each unit are first permitted to decelerate in unison, in a free rundown manner while the rotating speeds remain within the range permitting yarn spinning to continue, and these components are positively braked only when their speeds approach the lower limit of such range, while during restarting of the system, the yarn extraction device and the yarn winding device of each unit are caused to rotate through a selected distance in the direction opposite to their normal operating direction for feeding a fixed length of yarn back into the associated