Abstract: An open-end spinning device having a thread draw-off nozzle and a thread draw-off nozzle for an open-end spinning device, the thread draw-off nozzle having a thread-guiding surface which extends between an entry opening and a draw-off opening and which tapers in the shape of a funnel toward the draw-off opening. In order to provide a thread draw-off nozzle and an open-end spinning device having a thread draw-off nozzle which allows controlled production of the thread, the thread draw-off nozzle has a blocking element, which protrudes from the thread-guiding surface and which has a thread stop surface designed such that the thread stop surface blocks a thread from circulating over the thread-guiding surface.

Abstract: A thread draw-off nozzle for an open-end spinning device includes a nozzle insert configured to deflect a yarn produced by the open-end spinning device. A nozzle frame fixes the thread draw-off nozzle in the open-end spinning device. The nozzle frame includes a cylindrical shank, which has a centering diameter and a length that is shorter than half the centering diameter.

Abstract: A spinning rotor (3) for an open-end spinning device (1) operating in particular at high rotor speeds with a rotor cup (26), having a rotor bottom (6) and an opening (30) and having an annular wall section (31) designed as a fiber sliding wall. The rotor cup (26) in the transitional area between the rotor bottom (6) and the annular wall section (31) has a support collar (9) pointing away from the opening (30) of the rotor cup (26).

Abstract: A false twist device for an open-end spinning device to introduce a false twist in a yarn has a largely tubular carcass and several false twist edges arranged behind one another in the yarn draw-off direction and inclined by an angle in the carcass with regard to the yarn draw-off direction. The false twist edges protrude in such a way into the interior of the tubular carcass that the yarn experiences a deflection on each one of the false twist edges. The several false twist edges are arranged offset in such a way in the carcass in circumferential direction that the yarn simultaneously experiences a spatial deflection compared to its regular yarn draw-off direction through the successive deflections on the several false twist edges.

Abstract: A monolithic micro or nano electromechanical transducer device includes a pair of substrates (20, 25) respectively mounting one or more elongate electrical conductors (40) and resilient solid state hinge means (30, 32) integral with and linking the substrates to relatively locate the substrates so that respective elongate electrical conductors (40) of the substrates are opposed at a spacing that permits a detectable quantum tunnelling current between the conductors when a suitable electrical potential difference is applied across the conductors. The solid state hinge means permits relative parallel translation of the substrates transverse to the elongate electrical conductors.

Abstract: An open-end spinning rotor (3) is supported by its rotor shaft (4) in a spinning-rotor bearing (5) with the rotor shaft (4) detachably connected via a coupling device (29) to a rotor cup (26) such that the rotor shaft (4) remains supported in the spinning-rotor bearing (5) when the rotor cup (26) is removed. The coupling device (29) comprises a magnetic device (30) for fixing rotor shaft (4) and rotor cup (26) axially relative to one another and a mechanical rotational safety mechanism (31) for fixing rotor shaft (4) and rotor cup (26) radially relative to one another.

Abstract: A hard, wear-resistant ceramic surface is applied to spinning rotor cups in an electrolytic bath on which is imposed a shaped-wave electric current. A special electrode has been designed to facilitate application of the coating to the unique shape of a spinning rotor cup under the shaped wave conditions.

Abstract: Supporting disk for supporting a rotor of an open-end spinning machine, including a hub ring (1) and a supporting ring made of polymeric material secured to its outer circumference (2). The hub ring (1) is formed as a composite part, and is made of at least two different materials.

Abstract: The invention relates to an opening cylinder (2) of an open-end spinning device as well as a fiber sliver opening apparatus with such an opening cylinder. In at least one lateral area (6) of the opening cylinder (2) a sealing surface for an air gap seal (12) is formed. According to the invention the opening cylinder (2) has an air passage (14) in at least the one lateral area (6), the output side of the air passage lying within the sealing surface or adjoining the sealing surface directly and the input side of which being at a shorter distance from the rotational axis of the opening cylinder (3) than the output side. During the operation of the fiber sliver opening apparatus, air is conveyed through the passages (14) to the air gap (12) of the air gap seal arrangement or conveyed past it, so that the entry of air and pollutants into the air gap (12) is counteracted.

Abstract: A spinning rotor for open-end spinning machines and a method for balancing the spinning rotor in the course of a single clamping process by removing material from a cylindrical-shaped section of the collar (20) of the rotor cup (19) to form an identification mark (21) thereon sufficiently to offset an imbalance and equalize the mass of the rotor. The mark (21), which preferably consists of a combination of a graphic symbol (22) and lettering (23), is used for identification and information.

Abstract: In the case of an apparatus for open-end spinning, a fiber feed channel is arranged between an opening roller and a spinning rotor, which fiber feed channel tapers in a transport direction and which comprises a deflecting zone on its transport path. Immediately after the beginning of the deflecting zone, a bypass opening is provided, through which opening a part of the suction airflow transporting the fibers to the spinning rotor is drawn off. In the area of the opening roller, a bypass air inlet opening is provided additionally to support the suction airflow.

Abstract: A spinning rotor for an open-end spinning frame has a coating of a non-ferrous metal with hard material granules embedded therein, which is applied to the surface of the base material (12), in particular a nickel layer with diamond granules, wherein the coating is comprised of at least two layers (7, 10) containing hard material granules, and an intermediate layer (9) free of hard material granules between the layers (7, 10) containing hard material granules. In case of a separation in places of the wear protection layer, such as can be caused by a scraper in the course of cleaning the spinning rotor, wear protection and spinning properties at the damaged places of the spinning rotor are preserved. As a result, it is possible to prevent a considerable shortening of the service life of the spinning rotor.

Abstract: An open-end spinning device (1) with a forwardly-opening vacuum-loaded rotor housing (2), a high speed spinning rotor (3) rotating in the rotor housing and with a fiber conduit plate (4) for closing the rotor housing. The fiber conduit plate (4) has a replaceable conduit-plate adapter (10) forming the mouth area of a fiber guide conduit and a yarn withdrawal jet. The conduit plate adapter (10) is detachably fixed in a receptacle (7) of the fiber conduit plate (4) only in a frictionally connected manner by means of a magnetic coupling (15) which can be easily and rapidly detached when necessary yet is reliable and exact during operation and assembly.

Abstract: A spinning rotor adapted to be seated in a spinning box of an open-end spinning machine and having an identification mark (9), preferably embodied as alpha-numeric characters, formed at a location on the rotor cup (8) at which the information content of the identification mark (9) can be visually determined while within the spinning box after opening and stoppage of the rotor but without removal from the spinning box, thereby permitting a user-friendly, time-saving and dependable visual check of the spinning rotor type.

Abstract: A spinning rotor for use at high speeds in open-end spinning machines has a rotor cup having an annular wall portion defining a rotor opening, a bottom wall portion merging with the annular wall portion, and a mounting hub extending exteriorly from the bottom wall portion. A rotor shaft is affixed to the mounting hub coaxially with the rotor cup. The merger of the bottom and annular wall portions of the rotor cup defines a maximum exterior diameter of the rotor and an interior rotor groove. The annular wall portion, the bottom wall portion and the mounting hub are of different cross-sectional thicknesses with the cross-sectional thickness of the bottom wall portion increasing from the rotor groove to the mounting hub. The wall thickness is less than 1.

Abstract: An arrangement is provided for sealing the opening of a rotor housing under a low pressure, through which opening a shaft for a spinning rotor extends, which shaft is supported outside of the rotor housing. This arrangement comprises a sealing disk, which is supported floating relative to the opening and which is pressed against a bearing surface by means of a spring element. The floating sealing disk comprises a through bore hole having a narrow tolerance relative to the shaft. The spring element presses against the effect of the low pressure.

Abstract: A spinning rotor (1) with a spinning cup (2) has an interior surface coated with a nickel dispersion layer (6) of an essentially even layer thickness having a concentration of hard material grains (7) embedded therein which is clearly less at the surface of the fiber slide face (9) than in the rotor groove. The coating is produced by bathing the spinning cup in a nickel dispersion bath during the final stage of which the concentration of the hard material grains in the bath is reduced at least in the bathing area, while the spinning cup is moved in this bath and rotated around its longitudinal axis while maintaining the spinning cup in a spatial orientation relative to the bath wherein an imaginary plane passing through the rotor groove is at least approximately perpendicular to the surface of the nickel dispersion bath.

Abstract: A yarn withdrawal nozzle (20) for an open-end rotor spinning device (1) has a yarn inlet zone (29) tapering in a funnel-like manner into a yarn withdrawal conduit (21), with the yarn inlet zone being formed with both a spiral structure (30) as well as additional notches (34) in the inlet area of the yarn withdrawal conduit (21). As viewed in the yarn withdrawal direction (A), the notches (34) are either arranged following the spiral structure (30) or at least partially in the area of the spiral structure (30).

Abstract: The fiber sliding surface and the fiber collecting groove of an open-end spinning rotor are provided with hard particles embedded therein. After a certain length of operation time of the spinning rotor, the particles in the fiber collecting groove have a larger particle size than the particles in the fiber sliding surface. Thus it is ensured that the fiber collecting groove has a better "grip effect" relative to the fibers to be spun than the smoother fiber sliding surface.

Abstract: In the case of a rotor cup for an open-end spinning aggregate comprising a rough-surfaced fiber collecting groove and a smooth fiber sliding surface it is provided that hard particles are rolled into the fiber collecting groove. The fiber collecting groove is preferably provided with a soft nickel plating before the particles are rolled in, after which the nickel plating is then hardened.

Abstract: The present invention relates to a spinning device, e.g. an open-end spinning rotor (1) with a fiber guiding surface which is provided with a nickel-diamond coating (3) consisting of at least one inner bearing layer (30) and an outer working layer (31). The diamond grains (40) imbedded in the inner bearing layer (30), with a size between 3.5 .mu.m and 5 .mu.m, are larger than the diamond grains (41) imbedded in the outer working layer (31). The inner bearing layer (30) and working layer (31) are interlaced. In manufacture the fiber guiding surface to be provided with a wear-resistant nickel-diamond coating (3) is subjected to at least two coating procedures, whereby in the first coating procedure the bearing surface (30) is produced with larger diamond grains (40) and in the second coating procedure the working layer (31) is provided with diamond grains (41) which are smaller than the diamond grains imbedded in the bearing layer (30).

Abstract: In an open-end spinning machine (1) with a plurality of open-end spinning devices (3), each having a spinning rotor (15) whose rotor shaft (26) is seated in the bearing wedge of an axial thrust-free support disk bearing (27) and is positioned by a magnetic bearing (29), and a service unit (10), which automatically services the spinning devices, a sensor device (41) is provided on the service unit (10), which is connected to the control device (18) of the service unit (10) and checks an identification marker (34) applied to each spinning rotor (15). The control device (18) actuates a yarn piecing operation by the service unit only upon detection of an identification marker (34) identifying the spinning rotor (15) to be compatible with the associated spinning device.

Abstract: In the case of a rotor cup for open-end spinning aggregates, a smooth fiber sliding surface and a rough-surfaced fiber collecting groove are provided. By means of two separate plating processes, the fiber collecting groove is provided with a nickel-diamond plating and the fiber sliding surface is provided with a purely nickel plating.

Abstract: An open-end spinning rotor has a fiber collecting groove which is provided with fine roughenings. The fiber collecting groove includes additional profilings whose peak-to-valley height is at least five times the peak-to-valley height of the roughenings. This arrangement results in an improvement in yarn quality.

Abstract: An open end spinning method includes the step of providing a spinning chamber with an annular slip wall. A sliver of fiber material is placed onto the annular slip wall that widens continuously in the direction of sliver introduction into the spinning chamber. The angle of the annular slip wall to a rotational axis of the spinning chamber is between 8.degree. and 12.degree.. A yarn is formed from the fiber material in the yarn formation zone which is located within the portion of the annular slip wall upstream of a widest diameter of the annular slip wall viewed in the direction of sliver introduction. The fiber material is removed as a yarn from the spinning chamber through a yarn removal channel, extending along the rotational axis of the spinning chamber, in the direction opposite the direction of sliver introduction.

Abstract: A rotor for an open-end spinning machine. A spinning portion of a bottomed cylindrical body has a hollow portion where twisted yarn is formed by a continuous twisting operation while gathering short fiber groups in the maximum diameter portion of the spinning chamber. A rotary shaft is joined to the spinning portion. The spinning portion is made of a silicon nitride sintered body which includes no less than 60% silicon nitride grain having an aspect ratio not less than 3, and an average grain size of from 0.1 to 10 .mu.m. The rotor is hardly damaged at a high speed rotation of 100,000 r.p.m. or more, and the yarn strength and the yarn quality are not reduced even after an extended use of the rotor for a long time.

Abstract: An open end spinning rotor wherein the fiber guiding inner surface consists of a wear resistant surface layer of iron boride. The fiber guiding inner surface comprises a fiber sliding surface adjacent to a fiber collecting groove. The fiber collecting groove has a greater frictional resistance than the fiber sliding surface relative to the spinning fibers. This is achieved by means of a special structured surface of the fiber collecting groove. The structure surface of the fiber collecting groove can be created by a roughening of the boronized surface layer by means of a laser for instance, or alternatively, the structure can be created before the boron treatment by mechanical means such as roll pressing.

Abstract: An open-end spinning rotor for a textile machine includes a shaft and a supporting part received on one end of the shaft. A rotor pot is mounted on the shaft and is received by the supporting part. A coupling is operably configured between the rotor pot and the supporting part. The coupling comprises a first part configured on the rotor pot and a second part configured on the supporting part. An elastic element is incorporated with at least one of the first or second parts of the coupling to attenuate oscillations and vibrations which would be transmitted through the coupling.

Abstract: An adaptor in the form of an exchangeable extension adapted to the dimensions of an open end spinning rotor and in use is detachably connected with a spinning rotor cover. The adaptor comprises the first part of a yarn withdrawal channel as well as the end area of a fiber feed channel. The end area of the fiber feed channel continues the connecting part of the fiber feed channel located outside of the adaptor with a partioning joint. The transition from the connecting piece to the end area of the fiber feed channel is buckle-free or bend free. The end area of the fiber feed channel located in the adaptor has a curved area, which is also buckle-free or bend free. This curved area corresponds to the rotational direction of the spinning rotor and also comprises a component in axial direction of the spinning rotor. The curved area preferably extends with a constant radius over the entire adaptor.

Abstract: A yarn withdrawal nozzle for an open-end rotor spinning machine is provided with at least one ferromagnetic member. The at least one ferromagnetic member serves to couple the yarn withdrawal nozzle to a holding device comprising at least one permanent magnet. The permanent magnet is arranged sunk in a recess. The at least one ferromagnetic member comprises a projection with a diameter of approximately 2 to 3 mm. The projection can be guided into the recess and thus can be positioned to the permanent magnet. The projection serves also as an anti-rotating device.

Abstract: A rotor type open-end spinning machine of a structure in which fibers moving slidingly on an inner wall surface of an outer rotor (2) are prevented from falling at a location where a fiber bundle is being stripped off from a fiber collecting/bundling section (7) while being twisted concurrently. An inner rotor (5) is disposed within the outer rotor (2) and positively driven independently of the latter. A delivery passage (20) is formed in the inner rotor (5) for guiding a fiber bundle (F) bundled in a fiber collecting/bundling groove (7) to a yarn withdrawing passage (14). An annular negative-pressure chamber (6) is formed radially outward of the fiber collecting/bundling groove (7) of the outer rotor (2) with air discharge holes (9) being provided for communicating the negative-pressure chamber (6) to the exterior of the outer rotor (2).

Abstract: An open-end spinning device has a spinning rotor defining a fiber collection groove between a rotor bottom and an open-end of the spinning rotor. The rotor further includes a wall extending from the fiber collection groove to the open end of generally less than 6.0 mm. A rotor cover has an extension reaching into the interior of the spinning rotor. The extension includes at least a portion of a fiber feeding channel for feeding a fiber and air mixture into the rotor. A feed surface is disposed essentially parallel to a plane through a fiber collection groove into the extension adjacent the fiber feeding channel so that fibers exiting the feeding channel are directed along the feed surface. The feed surface has a radial dimension so that an open radial distance of less than 4.0 mm exists between the feed surface and the wall or fiber collection groove which is directly radially opposite of the feed surface.

Abstract: At least one circular ridge, which projects upwardly beyond the surface of the navel of the thread delivery device, is placed in the path of yarn being removed from the peripheral wall of the spinning chamber and delivered to the throat of the navel. The ridge has a height of at least 0.003" and is radially so located in proximity to the edge of the navel that the yarn being formed and lifted from the wall of the spinning chamber first engages the navel at the ridge.

Abstract: A spinning rotor for an open-end spinning device is proposed which is provided with a smooth surface at the critical locations in order to avoid deposits within the spinning rotor at its inner surface. The ring-shaped zone of the inner surface of the spinning rotor near its edge as well as the area of its bottom may for instance be made especially smooth by polishing.

Abstract: An open-end spinning machine has spinning stations and a magnetic and gas bearing with a stator at each of the spinning stations. A shaftless spinning rotor being electrically drivable with a single motor includes a series of spinning cups with different properties at each of the spinning stations for receiving fibers to be spun, and an electric rotor at each of the spinning stations forming an axial field motor with the magnetic and gas bearing and the stator. The spinning cups and the electric rotor have axially opposing end surfaces, and the end surfaces of the electric rotor and of one of the spinning cups at a time are coupled together to form a functionally appropriately releasable connection as a structural unit at each of the spinning stations.

Abstract: A drive for a shaftless spinning rotor wherein the spinning rotor is embodied as the rotor of an axial field motor utilizes axially opposed yoke-forming, magnetically conductive elements disposed respectively on the opposite sides of an air gap formed between the spinning rotor and the stator in combination with at least one magnet (preferably either permanent magnets or electromagnets) on one or both the rotor and stator arranged concentrically to one another and to the rotor axis. The present magnet/yoke arrangement does not require exact mutual alignment of oppositely located magnets nor their homogeneous polarization. The present arrangement is self-adjusting because of the generation of a point-symmetrical field which in operation forms a sort of magnetic potential depression. Magnetic drive and guide fields are advantageously decoupled in order to reduce their mutual interference.

Abstract: To spin a yarn with an open-end rotor spinning device, the fibers are fed to a fiber guiding surface from which the fibers are deposited on the sliding wall of a spinning rotor after passing over a gap. At the same time, an air stream is guided through the gap into the interior of the spinning rotor and is then removed from the interior of the spinning rotor without passing through the gap again. To produce the air stream, a device for the production of a pressure drop which produces the air flow flowing into the interior of the spinning rotor is assigned to the gap (17).

Abstract: A rotor type open-end spinning frame spins a yarn from a fiber bundle formed from unraveled fibers at a fiber collecting section while applying a twist to the fiber bundle during normal spinning, and which pieces the fiber bundle to a standard thread supplied to the fiber collecting section during yarn piecing. The spinning frame has a rotatable outer rotor which has an inner wall with a fiber collecting section. A conduit member is fixed opposite the open-end of the outer rotor and induct the fiber bundle and the standard thread therethrough. An inner rotor is disposed coaxially to and rotatable in the outer rotor. The inner rotor rotates independently of the outer rotor during both normal spinning and yarn piecing. A passage in the inner rotor communicates with the conduit member and guides the fiber bundle from the fiber collecting section to the conduit member during yarn spinning.

Abstract: Opened fibers are supplied into a rotor in high rotation, and a fiber bundle collected at a fiber-collecting section of the rotor is drawn as yarn from a yarn drawing passage provided on the open side of the rotor. A rotary assembly which is actively driven separately from the rotor is provided coaxially in the rotor. The rotary assembly has at least part thereof facing the vicinity of the fiber-collecting section and another part shaped to face a first end of the yarn drawing passage. The rotary assembly is provided with a yarn passage for guiding a fiber bundle to a position opposite the yarn drawing passage from the vicinity of the fiber-collecting section. A twist propagation preventing portion is provided in that end of the yarn passage that lies on the fiber-collecting section side. The rotation of the fiber bundle is suppressed by the twist propagation preventing portion, stopping the twisting.

Abstract: In a yarn draw-off pipe (4) for an open-end spinning device a twist stop element (5) is provided, consisting of several wires (50, 51, 52) wound in the same direction and in contact with the circumferential wall of the bore (411). The coils of these wires (50, 51, 52) are in contact with each other. The ends (501, 511) extend outward near the intake opening (43) essentially transversely to the bore axis. The twist stop element (5) is made in form of a replaceable insert.

Abstract: A process is provided for producing an open-end spinning rotor assembly. A boron treatment material is applied only to the fiber collecting groove area of the rotor of the spinning rotor assembly. Subsequently, a spinning enhancement material is applied over the boron treated fiber collecting groove and over a sliding wall area of the rotor. An assembly treated with boron treatment material and spinning enhancement material is also provided.

Abstract: The chiplessly formed open end spinning rotor (1) has, in the region of its collecting groove (11), a surface which has not been contacted by shaping tools. To produce it, a pot (3) is first made by stretching and stamping of flat material. This is then secured in its radial position independently of shaping tools. The peripheral wall of the pot (3), in the region between the later collecting groove (11) and the open edge of the pot (3), is upset inward by any optional kind of plastic deformation and the region later to be the collecting groove (11) by unsupported plastic deformation ["against air"].

Abstract: In an open-end rotor spinning device having a rotatable spinning rotor and a coaxial yarn withdrawal navel mounted in a rotor cover, a tubular twist choking member is removably mounted rotatably in general airtight relation to the cover at an angle with respect to the rotor axis with a yarn withdrawal tube affixed coaxially to the twist choking member. A curved passageway extends longitudinally through the twist choking member with plural obliquely-arranged yarn deflection elements constricting the convex side of the passageway. The twist choking member and the yarn withdrawal tube may be selectivey positioned rotatably as a unit to achieve a desired effect on spinning stability and yarn quality.

Abstract: An apparatus for open-end spinning is provided which includes a twisting element for twisting yarn. A yarn withdrawal nozzle is provided downstream from the twisting device in a yarn withdrawal direction. A yarn withdrawal device downstream from the yarn withdrawal nozzle withdraws yarn from the twisting device. A yarn deflection device is provided for deflecting yarn downstream from the yarn withdrawal nozzle. The yarn deflection device includes at least one false-twisting edge. The yarn deflection device includes a first deflection which deflects the yarn in a first direction and at least one additional deflection downstream from the first deflection which deflects the yarn into a direction deviating from the first direction.

Abstract: The invention relates to an open-end rotor spinning unit and particularly solves the problem of the relationship between a fiber defining stud of a separator, a fiber supply duct and a yarn take-off duct passing through the separator and the stud.According to the invention, there is established a dimensional relationship of the defining stud to the mean staple length of fibers, and the orientation of the supply duct at an acute angle to the front wall of a cylindrical projection partially engaging into the spinning rotor.In inner section of the peripheral wall of the defining stud is curved in the direction of a natural fiber flow trajectory into the direction of the spinning rotor rotation while the outer section is either in contact with or radially set back from the cylindrical wall of the projection at a distance of up to 4 millimeters from the edge of the wall.

Abstract: An improved navel member positioned in the cover of the spinning rotor of an open-end spinning frame includes a barrel having a longitudinal passageway extending therethrough. The axis of the passageway is substantially coincident with the thread path as it exits the spinning rotor. A cylindrical insert is fixed in the barrel passageway and includes a longitudinal channel therethrough through which the thread actually passes. A plurality of spaced longitudinal grooves in the inside wall surrounding the longitudinal channel receive elongated ceramic rods partially embedded therein. The rods form a plurality of spaced obstructions around the periphery of the longitudinal channel. The periphery of yarn passing through the navel member intermittently engages and disengages the ceramic rods causing an improved roughening and bulking effect.

Abstract: An open-end spinning device has a driven spinning chamber and an outlet tube mounted coaxially with the spinning chamber. A projection is provided on the inner curvilinear surface of the outlet tube, the projection extending along a spiral uncoiling in the direction towards the spinning chamber. The configuration of the projection spiral is chosen in such a manner that the projection of the angle formed between a tangent line to the spiral and a line drawn at right angles to the longitudinal axis of the outlet tube on an imaginary plane drawn at right angles to the longitudinal axis of the outlet tube in the zone of a portion of the spiral most distant from the spinning chamber is between 30.degree. and 40.degree. which corresponds to the angle of turns of the yarn produced in the spinning chamber.

Abstract: The spinning device for open-end spinning contains a withdrawal nozzle with a substantially spiral-shaped bead or ridge as well as a twist blocking element or twist trap containing beads or ridges and provided in a thread withdrawal passage. The inclinations of the substantially spiral-shaped bead or ridge and of the beads or ridges in the withdrawal nozzle and in the withdrawal passage, respectively, substantially extend in the same direction or sense as the twist of the yarn. This device permits increasing the stability of the yarn, reducing the number of thread breakages and/or increasing the production rate. The yarn characteristics are less dependent upon the fiber material and the yarn type. In particular, the production of yarns with a soft handle is rendered possible at higher rotor speeds than heretofore possible.

Abstract: In an open-end spinning rotor comprising two separately-formed rotor parts subsequently connected to one another, a parting gap between the two rotor parts opens into the fiber-collecting groove and is formed at least partially as a weld seam connecting the two rotor parts. At least part of the fiber-collecting groove may be formed by an insert ring to increase the wear-resistance of the groove. The ring, adjoining a sliding wall of the upper rotor part, is clamped between the two rotor parts and thereby radially inwards limits the parting gap inwards. To produce one of the present open-end spinning rotors, during welding the two rotor parts are so arranged relative to the welding location and rotated past the latter that the weld seam forms on the outside of the spinning rotor and does not project into the fiber-collecting groove.

Abstract: A spinning rotor for use at high speeds in open-end spinning machines has a rotor cup having an annular wall portion defining a rotor opening, a bottom wall portion merging with the annular wall portion, and a mounting hub extending exteriorly from the bottom wall portion. A rotor shaft is affixed to the mounting hub coaxially with the rotor cup. The merger of the bottom and annular wall portions of the rotor cup defines a maximum exterior diameter of the rotor and an interior rotor groove. The annular wall portion, the bottom wall portion and the mounting hub are of different cross-sectional thicknesses with the cross-sectional thickness of the bottom wall portion increasing from the rotor groove to the mounting hub. The wall thickness is less than 1.