Abstract: In the case of a procedure for preparing a piecing process in an open-end rotor spinning aggregate it is provided that a thread end, which is to be pieced in a fiber ring located in a spinning rotor, is first cross-cut, thinned-out and moistened. The dampening takes place subsequent to the thread being thinned-out, in that the thread end slides over a wetting surface.

Abstract: In the case of a procedure for preparing a piecing process in an open-end rotor spinning aggregate it is provided that a thread end, which is to be pieced in a fiber ring located in a spinning rotor, is first cross-cut, thinned-out and moistened. The dampening takes place subsequent to the thread being thinned-out, in that the thread end slides over a wetting surface.

Abstract: An endless transport belt transports a drafted fiber strand through a fiber bundling zone. The transport belt is provided with a perforation for a suction air stream which suctions the fiber strand. The transport belt is provided with a sufficiently smooth surface for sliding over a suction device. The transport belt can be in the form of an endless woven or knitted sieve belt or alternatively in the form of an extruded plastic apron having punched out holes.

Abstract: A condensing zone is arranged downstream of the drafting apparatus of a ring spinning machine, through which condensing zone an air permeable transport belt transports the drafted fiber strand. A cleaning element is arranged at the transporting element, which cleaning element takes the form of, for example, a cleaning roller, and which is pressed using a light pressure onto the transporting belt. The rotation direction of the cleaning roller preferably runs in the opposite direction to the direction of motion of the transport belt. The driven bottom roller of the front roller pair of the drafting apparatus can serve as a cleaning roller.

Abstract: A condensing zone is arranged downstream of the front roller pair of a drafting arrangement of a spinning machine, in which condensing zone a drafted roving or a sliver is condensed. The condensing zone has a suction device which has a closed hollow profile and which serves as a sliding surface for a circulating sieve belt. The sieve belt transports the drafted fiber strand to a nipping roller, which presses the fiber strand and the sieve belt against the sliding surface at a nipping point. The fiber strand travels over an essentially in transport direction extending suction slit located in the condensing zone, which suction slit extends to the nipping point.

Abstract: Flyer drafting arrangements deliver drafted fiber strands, whose width is greater than their height. Because of this, a condensing zone is often arranged downstream of the flyer drafting arrangements, which bundles the respective fiber strand laterally. Up to now, such condensing zones comprised mechanical condensers, which produced very unsatisfactory results. It is therefore provided in the present invention that a pneumatic condensing device is arranged at the condensing zone arranged downstream of the flyer drafting rollers. This condensing device can comprise a suction slit extending essentially in transport direction of the fiber strand, which suction slit is covered by an air-permeable transporting surface which guides the fiber strand.

Abstract: A condensing zone is arranged downstream of the front roller pair of a drafting arrangement of a spinning machine, in which condensing zone a drafted roving or a sliver is condensed. The condensing zone has a suction device which has a closed hollow profile and which serves as a sliding surface for a circulating sieve belt. The sieve belt transports the drafted fiber strand to a nipping roller, which presses the fiber strand and the sieve belt against the sliding surface at a nipping point. The fiber strand travels over an essentially in transport direction extending suction slit located in the condensing zone, which suction slit extends to the nipping point.

Abstract: A condensing zone is arranged downstream of the front roller pair of a drafting arrangement of a spinning machine, in which condensing zone a ready drafted fiber strand is condensed by means of rolling in the edge fibers before the yarn to be spun is imparted a twist. The condensing arrangement comprises a sliding surface having a suction slit extending essentially in a fiber strand transport direction, as well as a perforated transport belt which transports the fiber strand over the sliding surface and the suction slit. The sliding surface is the outer contour of a hollow profile, to which a suction device is connected. The transport belt consists of such a thin material that the fiber strand is disposed on the sliding surface and the suction slit at practically no distance thereto. The transport belt is preferably made from polyamide multifilament yarns.

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: A supporting disc for a supporting disc bearing of open-end spinning rotors consists of a disc-like base body and a running ring made of plastic. There are small, ball-shaped filling bodies, preferably of glass, embedded in the running ring. These filling bodies, which amount to between 0.1 and 10% of the total volume, have a diameter of, for example, 0.1 to 0.3 mm. After the peripheral surface of the running ring has been machined, a more or less porous running surface arises.

Abstract: A supporting disk for a supporting disk bearing of open-end spinning rotors comprises a disk-like metal base body and a thin running ring made of plastic. The outer diameter of the running ring measures at least 75 mm. The width of the running ring amounts to at most a tenth of its outer diameter. With these dimensions, the supporting disk can withstand the heat load at rotor speeds of over 130,000 rpm, so that often so-called cooling grooves and anchoring grooves can be omitted.

Abstract: In the case of an open-end spinning arrangement, a spinning rotor is arranged in a rotor housing, to which a vacuum of at least 500 mm water column is applied. A fibre feed channel, beginning at an opening roller with an entry opening, is directed with an outlet opening at a sliding wall of the spinning rotor. The fibre feed channel bends slightly in the direction towards a fibre collecting groove of the spinning rotor. The cross sectional area of the outlet opening of the fibre feed channel measures at least 19 mm.sup.2 and amounts to at least 30% of the cross sectional area of the entry opening. As a result of the bend in the fibre feed channel, the fibres are collected together in a fibre bundle on a longitudinal side of the fibre feed channel. The fibre bundle occupies only a part area of the outlet opening when leaving the fibre feed channel and is fed with high precision onto the sliding wall. The outlet opening can thus have larger dimensions without this leading to inaccurate feeding of the fibres.

Abstract: A supporting disk for a supporting disk bearing arrangement for open-end spinning rotors is provided with a disk-shaped basic body as well as an outer ring anchored to it. The circumference of the outer ring is constructed as a running surface for a shaft of an open-end spinning rotor. The outer ring and the basic body are made of plastic material. The outer circumference of the basic body and the inner circumference of the ring are provided with a surrounding undercut-type profiling respectively which engage in a form-locking manner and which are designed as a projection on the ring and as a recess on the basic body. The non-cut profiling is achieved by manufacturing the outer ring in a first tool and subsequently placing the ring in a second tool. The basic body is injection-molded to the outer ring on this second tool.

Abstract: In the case of a shaft coupling for bottom cylinders of drafting units on spinning machines, a shaft is provided on its end with an area of a reduced diameter which engages in a longitudinal bore at the end of the other shaft. In the area of the longitudinal bore, the two shafts are connected with one another by means of a screw thread. In addition to the screw thread, the area of the reduced diameter also comprises two centering surfaces with fits, one fit being a clearance fit and the other fit being a press fit. As a result, radial deviations of the shafts caused by the shaft coupling are to be avoided.

Abstract: In order to avoid a damaging of the guiding table and of the bottom apron guided around it when a lap formation occurs on the bottom delivery roller of a drafting unit, it is known to arrange the table top of the guiding table so that it can be swivelled away. In this known construction, a leaf spring is provided which holds the table top in its swivel position. In order to ensure a secure and precise guiding during the swivel movement of the table top, the new apron table is constructed with a projection which is provided on both sides with opposite surfaces which are positively guided during a swivel movement of the table top in a receiving device developed as a connecting link guide.

Abstract: A yarn withdrawal nozzle is provided for an open-end spinning arrangement, the essentially funnel-shaped contact surface of which consists of a material which, in a temperature range of approximately 50.degree. C. to approximately 100.degree. C., has a thermal conductivity of at least 80 W/mK (Watts per meter Kelvin) so that as a result damage to synthetic fibers caused by overheating is avoided also in the case of relatively high rotational rotor speeds.

Abstract: The present invention relates to a process for start spinning or piercing at least two yarns of fibers, which process includes forming strands for start-spinning or piecing by introducing a continuous filament into each roving, false twisting the strands, assembling the strands at a given point of convergence, cutting each filament upstream of its introducing point, removing the filament from the strands and twisting the strands without the filament to a twisted yarn. This process serves to overcome the problem of breaking at the start of the spinning. Also by the present invention, the problem of breaking while twisting the assembled intermediate yarns to a twisted yarn is avoided by introducing a false twisting of the assembled intermediate yarns, supplementary to the false twisting of the intermediate yarns, before the last twisting.

Abstract: A device is provided for interrupting the feed of a roving to drawing frames on ring spinning machines in response to thread breakage at a respective spinning unit. The device includes a clamping segment annularly clamped about a lower drawing roll and having abuttments for selectively lifting the upper drawing roll away from the lower roll to interrupt the feed of roving in response to movement of the clamping segment to an interrupting position. To control the clamping segment, a locking detent lever is provided which is spring-loaded into a locking position engaging the clamping segment and movable to an unlocking position in response to an electrical drive mechanism which, in turn, is controlled by a thread end break detection device. In particularly preferred embodiments, a capacitor is used to energize the drive means to unlock the lever, the capacitor being charged during normal spinning operation and discharged for a preset time period during the unlocking operation.