Abstract: A yarn piecing method in an open-end spinning machine comprises stopping a yarn piecing machine in front of a spinning unit suffering a yarn breakage, reversing a package with a rewinding roller to rewind a yarn therefrom, cutting off the yarn to provide a yarn end having a predetermined length, moving the yarn end to a position upwardly of an outlet of a withdrawal tube in the spinning unit, reversing the rewinding roller again to feed the yarn end through the withdrawal tube to a fiber collecting surface of a spinning rotor in the spinning unit, supplying a sliver with a feed roller into the spinning unit, piecing the yarn end to the sliver on the fiber collecting surface, continuously drawing a pieced yarn from the spinning rotor, and moving the pieced yarn to a position between a presser roller and a draw-off roller which are being rotated while drawing the pieced yarn from the spinning rotor.

Abstract: In the case of an open-end friction spinning machine having a plurality of spinning units that are arranged next to one another and having a movable servicing apparatus carrying out a piecing process, it is provided that approximately in the extension of the yarn formation zone facing away from the withdrawal device, a twist blocking device is provided for receiving a yarn end that is returned beyond the feeding point. The device for the yarn withdrawal is switched on when the yarn end is in the yarn formation zone of the friction elements so that the yarn end is opened up into a fiberbeard that is suitable for piecing while being held by the twist blocking device.

Abstract: A method of yarn piecing in a fasciated yarn spinning unit is disclosed by which a yarn having a broken end and drawn out from the yarn package is introduced through the false-twisting nozzle by conducting an intermediate portion of the yarn into a slit which is formed on a lateral side of the nozzle and extends to the yarn passage channel in the nozzle. Because the yarn has been previously cut into a predetermined length thereof, the cut end of the yarn is placed in the drafting zone of the drafting mechanism at a position where the cut yarn end overlaps a broken end of the fiber bundle. By restarting the spinning operation, the overlapping ends of the yarn and fiber bundle are drafted properly in the drafting zone and then the fibers in the overlapping ends are intermingled by the false-twisting effect of the rotary stream of jetted air while they are advanced through the false-twisting nozzle.

Abstract: In the case of an open-end friction spinning machine having a plurality of spinning units, each having a feeding and opening device with a feeding roller for the feeding of a sliver and with an opening roller for the opening of the fed sliver into individual fibers to be fed to a wedge-shaped gap, an automatic piecing process is provided. In the case of this piecing process, an already spun yarn end is returned into the wedge-shaped gap and, by means of a piecing, is pieced to newly fed fibers. It is provided that the quantity of fibers to be pieced by means of the returned yarn end is for each piecing process adjusted to a constant value by the fact that for each piecing process a sliver end is fed to the opening roller that has the same characteristics.

Abstract: A device for open-end friction spinning having two adjacently arranged rollers forming a yarn forming wedge-shaped gap therebetween is provided with a suction channel having an effect extending essentially in the direction of the wedge-shaped gap. This suction channel serves for drawing in a yarn end for a piecing operation. It is furthermore provided that this suction channel is selectively connectible to an air pressure source in order to provide a blast of air against the rollers in the region of the wedge-shaped gap. The blast of air serves to clean the rollers and remove debris prior to a piecing operation.

Abstract: An open-end spinning machine incorporating a doffer robot also includes separate tracks for the doffer robot and a piecer-cleaner robot. The robots are able to patrol continuously along one side of the machine and back along the other side of the machine, with sufficient separation for the doffer robot to pass the piecer-cleaner robot, and vice versa and for the two robots to pass end casings of the machine.

Abstract: An open-end spinning machine is disclosed having a piecing ability employing both a yarn reserve-forming member as well as reverse rotation of the yarn withdrawal rollers and of the package drive roll to pay out yarn from the package during formation of the yarn reserve, during the start-up cycle. This permits rapid dispensing of the yarn reserve on piecing, while allowing the reserve to be formed at a controlled rate before start-up and thereby minimizing the load on any auxiliary power source taking over in the event of shut-down of a multi-station spinning machine on power failure.

Abstract: A compressed air thread splicing device for producing a knot-free thread connection by splicing includes a splicing head having a splicing channel formed therein with two at least partially open ends for receiving threads to be joined in a given insertion direction and for alternately tangling, intertwining, swirling and winding fibers of the threads around each other, the splicing head having at least one compressed air inlet orifice formed therein leading into the splicing channel, the splicing head having at least one flow-channel formed therein branching off from the splicing channel transverse to the given insertion direction between the at least one inlet orifice and one of the ends of the splicing channel, and a switchable device connected to the at least one flow channel for generating a temporally limited current in the at least one flow channel in a flow direction away from the splicing channel.

Abstract: For the stopping and starting of an open-end friction spinning unit or of a spinning machine consisting of a plurality of such open-end friction spinning units, it is provided that the switching-off of the drives takes place in such a controlled manner that the yarn end forming by means of the switching-off of the fiber supply remains in the sphere of action of an auxiliary suction device. As a result, the restarting and the connected piecing are facilitated since the yarn end, in a controlled manner, remains inside the spinning unit and does not have to be returned by additional means. The yarn end is sucked into an auxiliary suction device and is preferably clamped in at least during the stoppage of the spinning unit or of the machine.

Abstract: An open-end friction spinning machine is disclosed which has a large number of spinning units arranged next to one another, each containing two friction rollers arranged next to one another to form a wedge-shaped yarn forming gap. By means of a joint drive the friction rollers are driven in the same rotational direction. A servicing apparatus is provided which in each case can be applied to a spinning unit, said servicing apparatus having an auxiliary drive for the friction rollers, said auxiliary drive containing an auxiliary drive element that can be applied simultaneously to the shell surfaces of both rollers.

Abstract: In the case of an arrangement for open-end friction spinning having two friction rollers that are arranged next to one another to form a wedge-shaped yarn forming gap, the frictional effect is reduced in the area of the yarn tip of the forming yarn. As a result, it is avoided that the yarn tip moves through the wedge-shaped gap. It is also ensured that a fiber transport takes place into this area of the wedge-shaped gap where the yarn tip is formed. This fiber transport is caused by an air current generated by an additional suction device, acting as an extension of the yarn tip.

Abstract: Each cover of a spinning station is provided with a rail element for guiding the service tender along the aligned spinning stations. In addition, the service tender carries a guide means in the form of a roller which has a cylindrical part to roll on the rail element of the covers when the covers are in a closed position as well as a frusto-conical part for rolling on the rail elements when the covers are in an open condition.

Abstract: For the piecing of a yarn of a spinning unit of an open-end friction spinning machine, it is provided that a yarn an brought into the wedge-shaped gap is pieced, while forming a yarn piecing, which, before a renewed winding-up of the yarn, is cut out and is replaced by a yarn connection connecting the new yarn with the yarn leading to the spool. The formation of the yarn piecing takes place at a production speed that is reduced as compared to the normal spinning operational speed, said production speed being brought to the operational value only after the making of the yarn connection. It is also provided that the yarn spun during the formation of the yarn connection is taken up by a yarn storage device, which is emptied more rapidly because of the fact that the wind-up speed as compared to the withdrawal speed has a larger speed difference than the operational wind-up speed has with respect to the operational withdrawal speed.

Abstract: A method for piecing on a thread in friction spinning machines, having at least one friction surface with a perforated wall defining a spinning wedge at the wall includes moving the friction surface, eliminating the movement of transport air through the perforated wall of the friction surface, supplying fibers to the spinning wedge, sucking away the fibers, subsequently moving a thread to be pieced on into the spinning wedge, resuming suction of transport air through the perforated wall of the friction surface, ending suction of the fibers, and continuously withdrawing the thread from the spinning wedge, and a device for carrying out the method.

Abstract: A process and apparatus for piecing a yarn at a spinning unit of an open-end friction spinning machine is disclosed. Before the return of the yarn end, the wedge-shaped yarn forming gap is exposed by moving away a lid-type component containing at least one part of the fiber feeding channel, after which the yarn end is introduced into the mouth of the fiber feeding channel of this lid-type component, and subsequently, the lid-type component is returned to its position covering the wedge-shaped gap. Subsequently, the actual yarn piecing process is carried out by switching on the yarn withdrawal device and the yarn feeding device as well as by the transfer of the end of the yarn end to the wedge-shaped gap.

Abstract: A process and apparatus is disclosed for improving the start-spinning of yarn on an open end friction spinning machine. To facilitate an exact alignment of the return yarn end to be pieced up with newly supplied incoming fibers, the respective spinning units are provided with a moveable cover part which in the open position exposes the yarn forming wedge slot between the friction rollers. Devices are provided for returning the yarn end and holding the same at a slight spacing from the friction rollers at the wedge slot and for sequentially timing the yarn draw off during start spinning with the activation of the fiber feed and the suction air flow related thereto.

Abstract: A process and apparatus for piecing a yarn at a spinning unit of an open-end friction spinning machine is disclosed wherein a yarn end, without exposing the wedge-shaped gap, is returned by means of an intake suction means, the suction effect of the suction device affecting the wedge-shaped gap being switched off. Preferably, the rollers forming the wedge-shaped gap are also stopped during the return of the yarn end section for piecing operations.

Abstract: An open end friction spinning machine is described with a plurality of spinning units which respectively each include two similarly driven, adjacently arranged, friction rollers forming a wedge slot for forming yarn, an inlet and opening device for guiding in individual fibers to the wedge slot, a fiber feed channel connecting the inlet and opening device with the wedge slot, a withdrawal device for withdrawing the formed yarn in the direction of the wedge slot and a suction device to hold the formed and forming yarn in the wedge slot. To facilitate improved start spinning yarn connections, each spinning unit is provided in the region of the ends of the rollers opposite the withdrawal device with a guide element which securely holds the return guided yarn end portion in the region of the fiber feed opening of the fiber feed channel prior to the actual start spinning process.

Abstract: A yarn piecing arrangement is disclosed for an open end friction spinning machine of the type having two friction rollers rotatably drivable in the same direction and disposed adjacent one another to form a yarn forming wedge-shaped gap therebetween, fiber supplying means for supplying individual fibers to the wedge-shaped gap, yarn withdrawal means for withdrawing spun yarn in the direction of the wedge-shaped gap, and suction device means for applying suction forces to hold the spinning yarn in the wedge-shaped gap. In order to facilitate fine control of the yarn piecing process, the friction rollers are stopped before the spun yarn end section is returned to the wedge-shaped gap. Once the yarn end section is positioned at the wedge-shaped gap, the rollers are restarted and yarn piecing is carried out.

Abstract: A method for yarn piecing in a fasciated yarn spinning unit, in which a yarn portion to be pieced is always nipped by a piecing roller means during the piecing operation, whereby feeding length and speed of the yarn in the piecing operation can be accurately controlled by the piecing roller means. Thus, a complicated restarting operation can be carried out in accordance with a predetermined time schedule.

Abstract: A novel method for yarn piecing in a fasciated yarn spinning unit, in which a broken end of a yarn and the fiber bundle to be pieced together are nipped and intermingled with each other between a soft nipping area between middle top and bottom aprons and thereafter are false-twisted by a vortex in an air nozzle. Motions of the associated parts are controlled as so to be able to achieve a suitable overlapping length of the yarn and the fiber bundle in the nipping area of the aprons.

Abstract: Method for starting the operation of a friction spinning machine, including friction surfaces movable in opposing directions for forming a spinning wedge, a device for supplying fiber to the spinning wedge, a thread withdrawal device, at least one suction device acting on the spinning wedge during the spinning operation, a suction tube disposed at an end of the machine opposite the thread withdrawal device, and a suction air source connectible to the suction device and to the suction tube, which includes:stopping the fiber supply and the motion of the friction surfaces;disconnecting the suction device from the suction source;supplying suction air from the suction source through the suction tube at the spinning wedge for inserting a thread into the spinning wedge;keeping the thread in a tensioned condition in vicinity of the spinning wedge;operating the suction device with a given suction power;moving the friction surfaces around the thread with a given speed to remove the twist of the thread at a given locati

Abstract: A method of starting the operation of a friction spinning unit having friction surfaces displaceable in opposite directions and forming a spinning wedge, the spinning unit further having a fiber infeeding device, a thread take-up device for drawing a thread longitudinally through the spinning wedge, and at least one suction device acting upon the spinning wedge, at least one of the friction surfaces being formed by a sieve drum, the suction device having a suction nozzle acting upon the spinning wedge by sucking air through the wall of the sieve drum, by means of an automatic thread joining device, includes:(a) laying a thread into the spinning wedge;(b) initiating the infeed of spinning fibers into the spinning wedge;(c) connecting the friction surfaces with a thread-joining drive arrangement, and moving the friction surfaces in opposite directions with increasing speed;(d) continuously withdrawing the thread from the spinning wedge, and conducting it to a waste collector;(e) interrupting the travelling thre

Abstract: A method of starting the operation of a friction spinning unit having friction surfaces displaceable in opposite directions and forming a spinning wedge, the spinning unit further having a fiber infeeding device, a thread take-up device for drawing a thread longitudinally through the spinning wedge, and at least one suction device acting upon the spinning wedge, at least one of the friction surfaces being formed by a sieve drum, the suction device having a suction nozzle acting upon the spinning wedge by sucking air through the wall of the sieve drum includes:(a) stopping the fiber infeed, and stopping the displacement of the friction surfaces;(b) stopping the flow of suction air from the spinning wedge through the wall of the sieve drum into the suction nozzle;(c) introducing into the spinning wedge through the wall of the sieve drum a suction air flow in a direction opposing the direction in which the thread is being drawn, and guiding the air flow out of the suction nozzle through the wall of the sieve dru

Abstract: A method for starting the operation of a friction spinning machine, including friction surfaces movable in opposing directions for forming a spinning wedge; the friction surfaces being movable in a spinning direction during a spinning operation, a device for supplying fiber to the spinning wedge, at least one suction device acting on the spinning wedge, a suction tube supplied with suction air, and a thread withdrawal device includes:stopping the fiber supply and the motion of the friction surfaces;stopping the suction;moving the suction tube through the spinning wedge in a given direction for sucking in thread and fiber remains;subsequently sucking a thread through the suction tube; moving the suction tube out of the spinning wedge in a direction opposite said given direction depositing the thread in the spinning wedge;resuming the suction at least as late as the step of moving the suction tube out of the spinning wedge;moving the friction surfaces in a direction opposite the spinning direction removing the

Abstract: An improved device to piece-up yarn and doff yarn packages on open-end spinning machines. The device comprises a carriage (12) equipped with specific means for the tasks of piecing-up yarn and doffing yarn packages, said carriage being supported cantilever-wise by an arm (13) secured to a trolley (15) able to run on lengthwise guides (17), said carriage (12) being equipped with an arm (20) to hold tubes which cooperates with a store (18) of tubes.

Abstract: Method for controlling a thread joining process having several thread joining steps and occuring by starting a rotor of an open end rotor spinning machine, which includes choosing a narrow limited rotor speed range for the beginning of a starting process of a specific thread joining step, which occurs after a first thread joining step, and selectively starting and finishing thread joining steps in substantially constant given intervals before and after the beginning of the starting process, and an apparatus for carrying out the method.

Abstract: An apparatus for sliver can controlling in a spinning mill having a plurality of spinning machines each comprising a plurality of spinning stations. The apparatus includes various lines of sliver can transporting tracks through which a full sliver can may be brought to a position adjacent to any of the spinning stations, as required. Sliver consumption quantities at the respective stations are computed by a control circuit as a central processing unit. When the sliver consumption at any one of the spinning stations reaches a predetermined quantity at which its sliver can is nearly empty, the control circuit operates to energize a warning means and means for indicating the number designating such spinning station calling for sliver can replacement.

Abstract: A yarn joined to a previously spun yarn is spun in friction spinning apparatus which comprises two juxtaposed, closely spaced apart twisting members, which define a triangular space, from which air is sucked. Singled stable fibers supplied to said triangular space are twisted together by said twisting members to form a yarn, which is withdrawn by a withdrawing device. A joint-forming portion of a previously spun yarn is provided in said triangular space in the region in which said fibers are supplied to said space, and said yarn is withdrawn while fibers are supplied to said triangular space so as to contact said joint-forming portion.

Abstract: A spinning machine wherein a yarn knotting truck having a knotter provided thereon travels in a truck travelling spacing provided along a number of spinning units further includes an apparatus for automatically doffing winding packages which have yarns fully wound thereon. A doffing truck which has provided thereon a doffing apparatus travels in the truck travelling spacing.

Abstract: Method of and apparatus for a continuous monitoring and analysis of spinning units operation in multiple unit open-end spinning machine. The invention permits the obtaining of reliable data about the operation of open-end spinning units in the machine, and of immediately processing them in the form of an analysis of the total performance of one or a plurality of machines. The active or inactive state of operation of the individual spinning unit is detected by a continuous monitoring of the spinning units at predetermined intervals consisting in emitting checking signals by a timing pulse generator of the monitor to those units. The signals thus obtained are used for analyzing the active state of the spinning units, the inactive state of the spinning units, the analysis of the active or inactive state of spinning units on each side of the machine, and an analysis of the production rate of the machine.

Abstract: Method for controlling a thread joining process which takes place by starting a rotor in an open end rotor spinning machine, which includes beginning pre-feeding of a fiber quantity into the rotor which is required for thread joining, and subsequently controlling the pre-feeding speed after the chosen draft for the following spinning operation, and an apparatus for carrying out the method.

Abstract: In order to wind a newly joined thread onto a tube newly inserted on a spooling device on an open-end spinning mechanism, the newly joined thread, together with a thread portion containing a leader, is guided away before the start of the bobbin build-up. Thereupon, the thread portion containing the leader is severed from the thread, and subsequently, the thread supplied by the open-end spinning mechanism is transferred to the newly inserted tube. To exchange a full bobbin for a new tube, a thread break is produced, the open-end spinning mechanism is cleaned and the thread is thereupon joined anew. To carry out this process, there are, on an open-end spinning mechanism, provided with a thread-joining device and a spooling device, a thread-suction device (4), a thread feeder (42) transferring the thread (35) supplied to the thread-suction device (4) to a newly inserted tube, and a thread-severing device (41) assigned to the thread-suction device (4).

Abstract: An apparatus for locating a servicing device which travels along a parent textile machine, such as a spinning frame, having a plurality of stations and stops at any designated station of the parent machine to there perform a servicing operation, such as yarn piecing or cleaning by use of fluid, such as compressed air or vacuum, supplied from a fluid source provided separately from the servicing device. The apparatus comprises, on each station of the parent machine, a stationary connector communicating with the fluid source and a locating guide member having a locating guide groove therein, and, on the servicing device, an air cylinder, a locating rod actuated by the cylinder toward and away from the locating guide member and engageable with the guide groove and a communicating member movable together with the locating rod and engageable with the stationary connector.

Abstract: To end or start the spinning operation on an open-end spinning unit by means of a switching device with which the connection to a spinning element or a delivery channel is alternately unblocked and blocked during the reversal of a switching device, the fiber flow is taken out of the region of the particular fiber path to be blocked, and only then is this region blocked. To influence the fiber flow, the volumetric flow rates of suction air flowing through the switching device are controlled. The switching device (6) has at least one closing member (60) with a first orifice (61) which leads to the spinning element (1) and the cross-section of which is enlarged geometrically in a discontinuous manner in the direction of the orifice opening, and with a second orifice which leads into the delivery channel (51) and the cross-section of which is reduced geometrically in a gradual way in the direction of the orifice closure.

Abstract: A method for preventing the irregular untwisting of yarn ends in pneumatic yarn splicing apparatus. The respective free yarn ends to be spliced are untwisted and loosened in the control nozzles and each untwisted yarn ends is cut at a predetermined position thereof. The cut yarn ends are overlapped in a splicing hole and spliced by the jetted fluid stream.

Abstract: Method and apparatus for yarn piecing in a ringless spinning machine is provided, according to which yarn piecing is accomplished by unwinding a yarn from its package, rewinding a portion of the unwound yarn on to the package at one, definite position, cutting off the yarn end to a predetermined length, then introducing the cut end of the yarn into the spinning mechanism of the spinning unit, and then withdrawing the yarn from the spinning unit after the yarn end is connected with the fibers in the spinning mechanism.

Abstract: Yarns are pieced in a spinning machine utilizing an air stream, such as an open-end spinning machine or an air-jet spinning machine. For yarn piecing, an end of a yarn unwound from a bobbin is inserted into a twisting mechanism, and a sliver is newly supplied as a fleece so as to intertwine with the yarn end forming a pieced yarn portion. The thickness of the unwound yarn is detected by a detector and stored in a memory prior to insertion into the twisting mechanism. After the yarn and the sliver have been joined, the thickness of the pieced yarn portion is detected by the detector, and the detected thickness is compared with the stored thickness of the unwound yarn. If the thickness of the pieced yarn portion exceeds an allowable value as a result of such comparison, then the yarn is severed by a cutter, and thereafter a cut end of the yarn is pieced again with the fleece.

Abstract: A method and apparatus for supplying operational fluid to a traveling-type working machine, such as a yarn piecer or an auto-doffer, which serves a parent machine, such as a spinning frame. The working machine utilized in the present invention has a secondary fluid tank and at least one nozzle attached to an air cylinder. Prior to the working machine serving the parent machine, the nozzle is advanced by an air cylinder, operated by fluid supplied from the secondary fluid tank, so that it engages with one of the air intakes provided on the parent machine. Then operational fluid is introduced from a primary fluid source into the working machine through the engaged nozzle and air intake, and thereby the working machine carries out a specific operation for the parent machine. Simultaneously, the operational fluid is distributed to the secondary fluid tank in preparation for the next engagement of the nozzle and the air intake.

Abstract: Method and apparatus for supplying vacuum to a serving device which travels along a multi-station parent textile machine such as a spinning frame and providing a servicing operation such as yarn piecing or package doffing to the stations of the parent machine are disclosed, wherein a vacuum duct, which has vacuum outlet openings corresponding to the individual stations of the machine and lids rotatably supported for closing the vacuum outlet openings, is arranged along the parent machine and the servicing device includes a nozzle which takes in vacuum from the duct. The nozzle is advanced toward the vacuum duct just before the servicing device reaches a station which calls for the servicing, and the end of the nozzle rotates the lid to uncover its vacuum outlet opening and then is stopped in alignment with the opening. Then, the nozzle is moved with the servicing device to rotate the lid thereby closing the outlet opening, whereafter it is retracted to its original position.

Abstract: According to the method of the invention, the broken end of yarn and the end of the fibrous strand are caused to move simultaneously opposite to one another and, after the ends of yarn and the fibrous strand are brought close together, they are caused to deviate from the path of their initial movement and to run at a distance from one another in such a manner that during the untwisting of the end of yarn it engages the end of the fibrous strand to form a knot. In an apparatus for carrying out the method for piecing the end of yarn to the end of the fibrous strand, there is provided a device for gripping and transferring the end of yarn to the pulling device, which is formed by a pipe having an outlet pipe connected to a source of reduced air pressure.

Abstract: On a spinning machine, especially an open-end spinning machine, which has a plurality of spinning units (10) each with a plurality of elements (4, 41) to be controlled electrically, there is a maintenance device (2) which is movable along the machine and which can be coupled electrically to the elements (4, 41) to be controlled of the particular spinning unit (10) located in its working range. One bus line (51, 52) is provided for identical elements (4, 41) to be controlled electrically of each of a plurality of spinning units (10). Furthermore, each spinning unit (10) has a switching device (55) which can be actuated as a function of the posiiton of the maintenance device (2) and which connects the various elements (4, 41) to be controlled electrically of a spinning unit (10) to the bus lines (51, 52) which are assigned to them and to which the maintenance device (2) is constantly connected.

Abstract: Method for controlling a thread joining process taking place by starting a rotor in an open end rotor spinning machine, which comprises beginning unwinding of the thread, subsequently controlling the thread unwinding speed in accordance with the rotor speed, and controlling at least one of the sliver drawing-in speed and the fiber feeding speed in accordance with the thread unwinding speed, and an apparatus for carrying out the method.

Abstract: In a pivotable suction tube (3) for taking up a yarn from a bobbin, there is provided for transfer of the yarn to an operating element, on its side facing the bobbin, an elongate slot (32), with which is associated a controllable closure piece (33, 35) extending over at least a substantial portion of it. The suction tube (3) possesses a tubular section (30) having a shape being symmetric to its axis with which is associated as a closure piece a rotatable slider (33) provided with an axial slot (330). The closure piece (33, 35) carries a stop (333, 352) with which is associated a counter-stop (20, 410) which becomes effective in dependence on the pivoting motion of the suction tube (3).

Abstract: An overhung mounted rotatable centering spindle (5) for centering a yarn (1) at an open-end spinning location is disclosed having a central groove (52) into which threaded grooves (500, 510) run together oppositely from both sides. The direction of rotation of the centering spindle (5) is reversible. Both threaded grooves have different core diameters (d.sub.1, d.sub.2), the smaller core diameter (d.sub.2) being towards the free end of the centering spindle (5) so that the yarn is immediately and with certainty ejected from the free end of the spindle during reverse rotation.

Abstract: A pneumatic yarn splicing apparatus 12 for spun yarns comprises a yarn quiding means 24, 25, yarn-cutting devices 22, 23, yarn end control nozzles 20, 21 and a yarn-splicing member 19. The yarn-splicing member 19 includes a flat jet nozzle 35 opened on a yarn-splicing hole 33 perforated through the yarn-splicing member 19.

Abstract: The invention relates to a method of and a system for controlling the operation of open-end spinning machines comprising a plurality of spinning units, which method is based upon a permanent cyclic communication of a central unit of the system with the individual spinning units. According to the invention, at a given instant, a single spinning unit only is connected to the central unit of the control system, said central unit being supplied with information data about the condition of the spinning unit connected thereto while said central unit simultaneously transmits instructions for said spinning unit, the other spinning units operating automatically on the basis of the stored instruction the validity of which lasts for the time of one control cycle.

Abstract: A method and apparatus for piecing a yarn in a spinning rotor of an open end spinning device is disclosed wherein an increased quantity of fibers is momentarily fed into the spinning rotor after the yarn is returned to the spinning rotor, whereupon the fiber supply is reduced to the normal supply quantity. Preferably, during termination of the spinning process, fibers are stored between a supply device and a fiber opening device which on commencing the piecing process are suddenly released, while at the same time the fiber supply resumes at the normal rate. For effecting the method an abutment surface (110) is preferably provided in a feed channel (11) on the side of a clamping point (15) of a clamping lever (5) for acting on the feed channel (11) facing away from the opening roller (2).

Abstract: Improved yarn spinning-in process and apparatus in open-end rotor spinning units which raises the quality of the spun-in point in the yarn to a level comparable with the quality of the entire yarn length. The yarn open end is pieced on to high-quality fibers while low-grade fibers are separated from the high-quality fibers and do not participate in the spinning-in process.

Abstract: Method and apparatus for splicing the ends of spun yarn includes means for inserting the yarn ends into a hole associated with a splicing nozzle having one or more air jet pipes, in which hole the ends are subjected to an air jet to join them each other. Yarn end control nozzles for the yarn on the package side and the yarn on the bobbin side are disposed at each end of the splicing nozzle to suck the yarn ends in the corresponding yarn end control nozzles, respectively and to keep the yarn ends free therein.