Abstract: A method and apparatus for production of a yarn, by plying, twisting or covering several staple yarns, subjected to a prior transformation, is provided. At least one of the staple yarns is different from the others and/or is subjected to a different prior transformation. The prior transformation may be carried out in parallel in the same machine, by independent transformation members able to be independently controlled. A slackening of yarn tension resulting from the prior transformation to give the desired tension at an assembly point is carried out on yarn feeding devices. Routing of the yarns is achieved by guide members towards the point of assembly, where the staple yarns are combined and arranged in parallel. A bobbin receives the assembled yarns in a device, constituting or associated with a positive feed device operating without slippage with relation to the yarn.

Abstract: For an air spinning frame, reluctance motors are provided for each spinning place to drive the pairs of rollers of the drafting unit, the drawing-off means, and the friction roller. Thereby, for the run-up of a spinning place, e.g., after a thread break, a specific frequency converter is provided. After reaching the stationary operating speed, a switch over onto a further frequency converter takes place, at which time, the corresponding reluctance motors of the other spinning places are driven in parallel. By the use of reluctance motors it can be done without a complex speed regulation means. A specific dimensioning of the reluctance motors permits a very fast run-up and a particularly good efficiency during the stationary operation.

Abstract: An apparatus for manufacturing stranded cables from strand elements with alternating twist directions (SZ stranding). One or more storage disks can be disposed between a guide that receives the strand elements and a stranding disk. The stranding disk and the storage disks can be driven in alternating directions. At least one torsion element drives the storage disks with a respective rotation speed that decreases with increasing distance between the storage disks and the stranding disk. The torsion element can be driven at several locations with a different rotation speed.

Abstract: A spinning rotor of an open-end spinning device is slowed down for piecing to a low rotational piecing speed and is then accelerated to the operating speed. For this purpose, the spinning rotor or an element in driving connection with it is presented a drive transmission device from a service unit by means of which the spinning rotor can be switched from normal production speed to a reduced piecing speed and back. In this process, the drive transmission device can be driven either by a driving apparatus installed on the service unit or by a drive belt extending within spinning machine. The driving apparatus mounted on the service unit is connected to a control device for the control of the evolution of the rotational speed of the spinning rotor. The spinning rotor is driven according to a rotational speed course controlled by means of a program applied by the control device during the time when its rotational speed deviates from its operating speed.

Abstract: A method, apparatus and system for improving reverse oscillating lay (ROL) consistency during an optical cable manufacturing process. A torque capstan receives an optical fiber cable from an ROL machine that places reverse-oscillating lay on the core of an optical cable, but also generates some undesirable fluctuating back-tension in a direction opposite a direction in which the optical fiber cable is being pulled during manufacturing of the optical cable. The optical cable comprises a plurality of subunit cables. A drive system coupled to the torque capstan is controlled by a control system in such a way that the torque capstan applies a certain amount of force to the optical cable in a direction substantially parallel to the direction in which the optical cable is being pulled during manufacturing.

Abstract: A device and a process for controlling the motor drives (121) of textile machines, comprising at least one “encoder” (101), capable of controlling the number of revolutions of each motor (121), and at least one central electronic unit (111) processing the data originating from all the motor drives (121), based on an application program containing the synchronizing data between the individual motors (121) and the technological operating parameters of the textile machine.

Abstract: It is an object of the present invention to provide a hairiness controlling device that can start, simultaneously with the start of spun yarn running, stabilizing a spun yarn run through disks. According to the present invention, a rotation speed of each disk 6 is varied depending on a running speed of a spun yarn Y run as a drive drum D rotates, thereby setting the tension of the spun yarn Y at an appropriate value when the spun yarn starts to run.

Abstract: To provide an individual-spindle-drive type multiple twister that enables the position of a spindle that has stopped due to a malfunction to be promptly identified, thereby making it possible to drive and stop each spindle easily. An individual-spindle-drive type multiple twister M comprising a large number of twisting units installed in a line, each of which rotates a spindle so as to twist yarn Y1 released from a supply package P, and each of the spindles having a spindle drive source 8, wherein a switching means 23 corresponding to the spindle drive source 8 for each spindle is provided at the same or approximately the same height relative to a machine body in order to drive and stop the spindle drive source for each spindle.

Abstract: A roving frame has a drafting frame receiving sliver and feeding rovings to respective roving winding stations. Respective spindles at these stations receive core sleeves on which the roving bobbins are wound for respective flyers. An evaluating and control device is operatively connected to the drive for automatically or on command, operating the flyers at a first gentle speed less than the operating speed and a speed required for automatic capture of roving ends by the core sleeves, automatically or on command, operating the flyers at a second gentle speed less than the operating speed, greater than the first gentle speed and sufficient for automatic capture of roving ends by the core sleeves, and automatically or on command, operating the flyers at a creeping third gentle speed less than the first gentle speed for startup and to position the flyers at selected angular positions.

Abstract: A method of controlling the manufacture of false twist textured yarn characterised by adjusting non-isothermally in a closed loop the heat flux taken up by the yarn in tension to a specific yarn dyeability. Adjustment can be achieved by feeding back the output of a direct-acting yarn texture sensor to control at least one of yarn heater heat supply, yarn twist speed and yarn feed speed. The sensor is arranged to sense at least one of textured yarn speed, yarn temperature, yarn bulk and yarn tension. A very compact texturing line is possible when the control method is applied.

Abstract: Apparatus and process for the production of stranded wire from copper wire, whereby the stranded wire is wound upon a spool by means of a transfer mechanism. A control arrangement is provided, which regulates the rotation of the spool, the motion of a transfer element which is a component of a transfer mechanism and a separate drive for the transfer mechanism.

Abstract: A pair of tangential belts disposed for parallel movement on the left and right locations for individually driving a pair of left and right spindle trains disposed in a back-to-back relationship to each other are individually driven by means of a pair of motors at the opposite ends of a machine base, and a right take-up mechanism train is driven by a speed change gear connected to a driving pulley for a belt while a left take-up mechanism train is driven by another speed changing device connected to a turn pulley for a belt, the speed changing device and being disposed collectively at an end of the machine base.

Abstract: Method and apparatus for providing proper tension on a stranded conductor, as the conductor is formed and collected on a take-up reel or bobbin, by using a strain gage to monitor the tension of the conductor being collected and to provide a signal to a controller which in turn increases or decreases the speed of a direct current, variable speed, motor used to drive the take-up reel or bobbin, thereby providing proper tension to the conductor being collected.

Abstract: A method and system are provided for automatically controlling tension of an armour tape being wrapped around a continuous strand of material, such as an electrical cable, travelling through an armouring machine having a reel of tape and tape feed rolls rotating around the strand and having a motor or suitable variable speed drive (such as a P.I.V. variable speed drive) for controlling the speed of rotation of the tape feed rolls and thus of tape feed rate. To achieve automatic control, the diameter of the strand entering the machine is measured, preferably by a laser, and the diameter of the armour over the strand exiting the machine is also measured, also preferably by a laser. The measurements are communicated to a computer which compares them to preset values. The computer drives the motor or variable speed drive and adjusts them when required depending on the measurements of the two diameters and so as to maintain the preset values during the wrapping operation.

Abstract: A rotor spinning machine has a plurality of simultaneously operated spinning stations each with a spinning rotor, an opening roller, a feed roller for delivering sliver to the opening roller, and a stepping motor connect directly to the feed roller for driving thereof. An actuating arrangement is provided for selectively actuating each stepping motor in a normal increment mode during spinning operation and in a microincrement mode during yarn piecing operations.

Abstract: A process for piecing a broken yarn on an open-end spinning device in which the fiber feed to the fiber collection surface, and which has been interrupted during stoppage of the open-end spinning device. The fiber feed is switched back on and is immediately brought to full production speed. In this process the combed-out state of the fiber tuft at the point in time of when fiber feed is switched back on is ascertained. The point in time when yarn draw off is switched back on and the speed of it are adapted to when the feeding of fibers to the fiber collection surface becoming effective. The yarn is subjected to a multi-phase acceleration. The first phase of the draw-off acceleration is adapted to the incorporation of fibers into the back-fed yarn end. At least one additional phase of the draw-off acceleration serves to reach and/or to maintain the desired fiber mass.

Abstract: The present invention provides a process and device for the reduction of energy consumption in operating spinning elements in driving spinning rotors of open-spinning machines or the spindle drive of ring spinning machine or the roving frame. It is the object of the invention to constantly keep energy consumption in the operation of spinning element at a minimum. Contact pressure between each spinning element and the indirect driving device is adjusted as a function of the momentary difference between the rotational speed of the spinning element and of its driving device in stationary operation while rotational speeds only nominally change, so that the slippage between indirect driving device and spinning element remains constant in time.

Abstract: In a roving winding apparatus applied to a roving frame provided with a plurality of draft parts and corresponding bobbin wheels, a bobbin shaft for driving the bobbin wheel, a bobbin rail on which the bobbin shaft is rotatably horizontally mounted along the longitudinal direction thereof, a lifting motion mechanism for lifting the bobbin rail, and a main motor for driving the draft parts at a predetermined rotational speed, wherein the bobbin shaft is driven under a controlled condition created by a servomotor to follow a digital signal output from the rotation angle detecting device applied to the common bottom front roller of the draft parts, in an adjusted optimal condition under the control of a computer system, incorporated with the lifting motion of the bobbin rail.

Abstract: A process for piecing a broken yarn on an open-end spinning device in which the fiber feed to the fiber collection surface, and which has been interrupted during stoppage of the open-end spinning device. The fiber feed is switched back on and is immediately brought to full production speed. In this process the combed-out state of the fiber tuft at the point in time of when fiber feed is switched back on is ascertained. The point in time when yarn draw off is switched back on and the speed of it are adapted to when the feeding of fibers to the fiber collection surface becoming effective. The yarn is subjected to a multi-phase acceleration. The first phase of the draw-off acceleration is adapted to the incorporation of fibers into the back-fed yarn end. At least one additional phase of the draw-off acceleration serves to reach and/or to maintain the desired fiber mass.

Abstract: A yarn is fed at a piecing speed to the fiber collection surface of a spinning rotor. It is there combined with the fibers of a fiber ring and is then drawn off from the spinning rotor in the form of a continuous yarn while fibers newly fed into the spinning rotor continue to be incorporated in the yarn. The rotor speed is changed, immediately after piecing, from the piecing speed to a rotational speed which is lower than the piecing speed. The rotor speed is then increased to the production speed. In this manner, optimal conditions are achieved with respect to propagation of twist and draw-off of the piecing joint. To carry out this process, elements are provided for the reduction of the rotor speed from piecing speed to a lower value, for renewed acceleration of the rotor speed after a desired minimum value has been reached of after the passage of a predetermined period of time, as well as elements to tie the accelerating rotor speed to the desired production speed.

Abstract: A yarn is fed at a piecing speed to the fiber collection surface of a spinning rotor. It is there combined with the fibers of a fiber ring and is then drawn off from the spinning rotor in the form of a continuous yarn while fibers newly fed into the spinning rotor continue to be incorporated in the yarn. The rotor speed is changed, immediately after piecing, from the piecing speed to a rotational speed which is lower than the piecing speed. The rotor speed is then increased to the production speed. In this manner, optimal conditions are achieved with respect to propagation of twist and draw-off of the piecing joint. To carry out this process, mechanisms are provided for the reduction of the rotor speed from piecing speed to a lower value, for renewed acceleration of the rotor speed after a desired minimum value has been reached after the passage of a predetermined period of time, as well as mechanisms to tie the accelerating rotor speed to the desired production speed.

Abstract: In the high speed driving of a ring spinning frame provided with a plurality of ring-spinning twisting-winding units, to compensate for the possible loss of thickness of yarn produced, when the drive speed of the spindles reaches more than a predetermined rotation speed, such as 16,000 rpm in the case of spinning a cotton yarn of 40's, a total draft ratio of each drafting part of the ring spinning frame is regulated to maintain the expected yarn count according to a predetermined compensation program.

Abstract: In a ring spinning or ring twisting machine the spindles of which each have an asynchronous motor as drive means, and the auxiliary apparatus thereof are driven by at least one electric motor having variable rotational speed, and the ratio of the rotational speeds of the electric motor driving the auxiliary apparatus and the asynchronous motors remains constant, a reluctance motor is used to drive the auxiliary apparatus. Two converters are used which are controlled in such a manner that the speed ratio remains constant.

Abstract: The invention provides a means of controlling the speed of operation of a material processing apparatus, such as a ring spinning machine in a textile mill. The purpose of the invention is to allow high speed processing, while maintaining a high quality product. In the case of ring spinning for instance, the object is to reduce the incidence of yarn breakages.The method in accordance with the invention includes controlling the speed of operation during a total time for processing a finite quantity of the material, and including the use of an automatic control apparatus preset to change the speed of the driving motor in a series of very small increments throughout a speed change time which is a predetermined percentage of the total time, between two speeds, one of which is a predetermined optimum operating speed and the other of which is a predetermined percentage of the operating speed.

Abstract: A twist number setting device for a two-for-one twister constituted such that an output power shaft of a drive motor is connected to a drive pulley which is connected to a spindle and provides a turning force to the spindle and also connected to a rotary shaft of a drum which contacts with a winding package and provides a turning force to the package, and a speed change means is interposed between the output power shaft of the drive motor and the rotary shaft of the drum.

Abstract: A spinning machine has an electric motor for rotating a bobbin-supporting spindle to build a package of yarn thereon and a funnel for guiding yarn onto the spindle. The spindle is rotatingly driven by an electric motor and the electric motors of the spindle and the funnel are commonly connected to a frequency control means which is, in turn, connected to an electrical power supply means. The torque of the funnel electric motor is a function of a characteristic of the funnel in accordance with the relationship that the funnel is rotated by its electric motor at a lower rate relative to the contemporaneous rate of rotation of the spindle. The apparatus can include a switch assembly selectively movable between leads for selectively connecting the funnel electric motor to the frequency control apparatus to operate the motor or to the electrical power supply means to brake the motor.

Abstract: A stranding machine, and a method for controlling same wherein a measurement device is utilized to measure the centrifugal forces of a spool of the stranding machine. The strand spool rotation rate is then regulated dependent upon the measured centrifugal forces. As the material is depleted from the spool, the spool rotation rate is increased while maintaining a centrifugal force reading within given perimeters.

Abstract: A device for the control of an open-end spinning element, including a pivoted control lever (4) is provided which is capable of assuming three different working positions. In a production position the control lever brings a first drive, running at production speed, into driving contact in the operation of the open-end spinning element. In a braking position the control lever brings a brake to act upon the spinning element. The control lever in a piecing position brings a second drive which runs at a lower speed than the first drive into driving contact with the open-end spinning element. At least the positions determining the production and the piecing position of the control lever are provided with a common control element, capable of being moved back and forth in the direction of movement of the free end of the control lever between at least two switching positions.

Abstract: To decrease the time required for spindles of a spinning machine to reach their normal operating speeds after a yarn breakage or the like, where the spindles are individually driven by respective asynchronous motors individual to the spindles, the alternating current source whose frequency defines the speed of the motor is temporarily brought to a voltage above the normal operating voltage and the voltage step-up is then terminated.

Abstract: A method of controlling a roving frame to produce good quality results with fewer procedural interruptions and without knowing precise parameters of the textile material being processed. To this end, optimum roving tension during the laying down of each roving layer on a bobbin is successively determined from nominal values for bobbin rotational speed based on only a one-time estimate of material parameters.

Abstract: For compensation of changes in rotational speeds, for example, occurring because of varying loads on the motors, the drive mechanisms for at least two kinds of working units have a common synchronizing mechanism and are connected operably by a torque transfer device. The torque transfer device comprises, for example, a drive belt and two drive pulleys, each of which is attached to a different drive mechanism. The common synchronizing mechanism can comprise either a common rotational speed control or an adjustable current supply for the motors of the drive mechanisms.

Abstract: In the case of an open-end friction spinning machine having a plurality of spinning units, measuring devices are provided for examining the quality of the moving yarn at each spinning unit. Preferably, the tension of the yarn between a withdrawal device and the yarn forming point is measured which permits the drawing of conclusions concerning the respectively existing yarn twist. When deviations from an indicated quality are determined, measures are taken so that at least one parameter of the spinning conditions at the respective spinning unit is changed for eliminating the deviations.

Abstract: A rapidly reacting measuring element is used at the delivery of the drafting zone on autolevelling drawframes used in the textile industry, which makes it possible to superimpose on the signal thus obtained from the measuring element by means of an electronic system a further measurement signal at the delivery of the drawing passage and thus correct the parameters governing the drafting values in such a way that even short-term variations in cross-section of the textile material are levelled out. The critical factors here are especially the delay time T of the textile material between the correcting element (pair of drafting rollers with variable speed of rotation) and the measuring element and also the overall amplification V of the measurement signal.

Abstract: This invention relates to a sensor device able to provide, without contact, an exact indication of the tension in the free portion of each individual thread which leaves the rotating head of a stranding machine in order to contribute to the formation of a rope.

Abstract: In order to maintain a desired feed velocity in a glass-fiber thread passing via a traveler from a supply bobbin to a cop on a spindle, the thread is led upstream of the traveler through the nip of a pair of rollers that are set in rotation by its motion to drive a tachometer working into a speed regulator which controls the bobbin drive. The output signal of the tachometer may further be used to measure the length of thread payed out from the supply bobbin and/or to generate an alarm signal stopping the bobbin and spindle drives in the event of a slowdown of the roller rotation indicative of a thread break; such an alarm signal could also be produced when a speed sensor coupled with the bobbin drive detects an excessive increase in its operating speed caused in the event of a thread break by feedback from the tachometer.

Abstract: A method of, and apparatus for, manufacturing a stranded product from materials wound on feed reels journalled in a rotating feed cage. To permit operation at a maximum safe speed based on centrifugal force of the mass of material on the feed reels, an energy beam such as light is arranged to sense the diameter of the various feed reels. Cage rotation is then increased as permitted according to the observed diameter of charge of material on the reel having the greatest charge.

Abstract: A single-twist stranding machine includes a stranding disc and nipple for stranding together a plurality of filaments, wires, conductors or the like, a rotatably mounted take-up spool onto which the stranded-together elements are wound, a flyer coaxial with the spool and including a frame and deflection pulleys to run the stranded-together elements from the stranding means to the spool, the flyer revolving about the spool, and a common drive motor. The specific improvement disclosed includes a differential gear transmission having two input gears and an output gear; a first transmission for drivingly connecting the drive motor to the flyer, one of the input gears of the differential gear transmission is a part of the first transmission; a second transmission drivingly connects the output gear to the spool for causing the spool to rotate; and a control drive operates the other input gear to vary the speed relation of flyer and spool in dependance upon the input speed of the stranding elements.

Abstract: A process and apparatus for producing a twisted elastic thread in which an elastomeric thread of substantially 154 dtex to 310 dtex, is adhesively twisted with two yarns. The thickness of each of the two yarns is substantially of 100 to 12,500 dtex, and the yarns preferably are OE yarns of polyvinyl chloride, polyvinyl cyanide, polyacrylonitrile and/or wool threads, preferably produced by the rotor process. Prior to twisting, the yarns are surface-swelled under a vacuum between substantialy 0.1 and 0.2 bar in superheated steam at substantially 70.degree. C. for up to ten minutes for loosening purposes. During twisting, a pre-tension is imparted to the elastomeric thread with respect to the yarns. Such pre-tension is imparted to the elastomeric thread only a predetermined time after starting the twister, and the elastomeric thread is pre-tensioned by substantially 2 to substantially 5 times compared with the yarns.

Abstract: Tension is reduced in the unwound length of roving remaining between the drafting mechanism and the package after the frame has been brought to a halt. This can be done by additional feed from the drafting mechanism after stopping of the other elements of the frame. A tension adjusting means is coupled into the drive to the rollers of the drafting mechanism to advance the mechanism the desired amount. The degree of feed may be different depending upon whether the stoppage is due to a break at one of a group of flyers, or to a doffing operation.

Abstract: A yarn-body core is supported by an upright spindle adjacent a vertically displaceable yarn guide through which a yarn to be wound passes to the core. The core and spindle are rotated and simultaneously the guide is displaced upwardly along the core to wind the yarn on the core until an instant when a yarn package having a predetermined size is formed on the core. Thereafter the guide is lowered to a level below the core while the spindle continues to rotate to wind several turns of the yarn on the spindle below the core. The rotation rate of the spindle and the core is decreased to a relatively low level prior to the instant when the yarn package is completely formed and thereafter this rotation rate is decreased to a standstill in accordance with a predetermined program starting at the instant the yarn package is fully formed and ending when several turns have been wounded on the spindle.

Abstract: An assembly of motors designed to drive a ring rail, a bank of spindles and a plurality of draw or delivery rollers in a ring spinning or twisting machine is supplied with three-phase current of a frequency determined by the settings of digitally adjustable frequency selectors independently controlling respective solid state frequency-inverters assigned to the several motors or groups of motors. The selectors include frequency dividers in the output of a common and preferably also adjustable source of timing signals which may be a free-running oscillator or a pulse generator driven by one of the motors acting as a master.

Abstract: An apparatus for twisting and winding strand onto a rotating bobbin comprises a spindle located within an open top pot both mounted for coincident rotation about a common axis. A strand guide mounted on the wall of the pot guides strand from an external source to be twisted and wound onto the bobbin. During rotation of the bobbin and pot, the pot is axially reciprocated relative to the bobbin to layer the strand while strand tension is monitored by a transducer located in the strand supply path. Strand tension is controlled by controlling the differential between the speeds of rotation of the bobbin and pot in response to the output of the transducer and a reference, as taught in my U.S. Pat. No. 4,128,988.

Abstract: A multiply effect yarn is wound up from a plurality of strands on a yarn-winding body that is rotated at a variable predetermined speed. Each of the strands is fed via a respective strand-feed element to the yarn-winding body. The feed rate of each of these strand-feed elements can be individually varied, and is established as a function of the rotation rate of the yarn-winding body to maintain a predetermined proportionality between the various speeds. The drive for each strand-feed element comprises a separate pair of variable-speed motors set to operate at different speeds and operated by forward and backward counters so that either the one motor or the other motor of each drive is connected to the respective feed element which can also be connected to a brake, if desired. The various speed rates can rapidly be adjusted, in accordance with the overall drive rate for the yarn-winding body, even during production of the multiply effect yarn.

Abstract: To start-spin a thread with open-end spinning, the end of the thread is inserted into a spinning rotor against the normal direction of draw, placed on a ring there formed of fed fibres and drawn off again. The end of the thread is placed on the ring at a start-spinning speed which is lower than the operating speed of the spinning rotor. In order to avoid undesired changes in the thickness and strength, etc. of the thread at the start-spinning point, the feed of the sliver, which determines the thickness of the ring of fibres located in the spinning rotor, is reduced in a ratio to the normal operating condition which at least approximates the ratio between the start-spinning speed of the spinning rotor and its operating speed.

Abstract: On a ring spinning or twisting frame having winding units with rotatable thread follower rings, the difference in the speed of rotation between the ring and its follower during the restarting of the winding unit, after repair of a thread break, is maintained within acceptable limits while the frame continues to run at its high operational speed, by controlling the rotational speed of either the ring or the spindle, the speed of the controlled element being varied either continuously, or in one or more steps during the restarting operation.

Abstract: A device for controlling the bobbin drive of a flyer roving frame which has a bobbin, a flyer and drive roll thereon that are utilized for building a bobbin with yarn. A drive for the frame incorporating a differential gear and controls are provided for adjusting the driving speed of the flyer and drive roll stepwise to different rotational speed stages during the building of the bobbin. An additional speed adjusting device is provided for automatically varying the driving speed of the bobbin within each rotational speed stage. A switching device is provided for automatically switching the rotational speed stages.

Abstract: A centralized control system for open end spinning machines comprises a group control unit essentially consisting of a first spinning control means composed of a plurality of sequentially operated logical elements connected in series, the first spinning control means producing from the respective logical elements parallel outputs each of which is fed to a plurality of spinning units so as to control the spinning operation thereof, and an individual control unit essentially consisting of a second spinning control means each of which constituent is the same as the first spinning control means. A spinning mechanism includes a yarn breakage sensor provided in the stream of spun yarn, a driving means for driving the spinning mechanism including a plurality of driving motors, controlled by the output from the group or individual control unit.

Abstract: An adapter pulley for increasing the speed of a spindle drive of a rubber covering textile machine includes an adaptor body member having a tapered drive belt transfer surface tapering inwardly to a reduced drive pulley portion.

Abstract: The present invention relates to a method and an apparatus for changing the ratio of the yarn taking-up speed to the number of revolutions of the rotor at the time of yarn piecing and normal spinning. According to the present invention, the ratio of the yarn taking-out speed to the number of revolutions of the rotor at the time of yarn piecing has a different value from that employed at the normal spinning, while the ratio of the yarn taking-out speed to the sliver supply speed is made constant at the time of yarn piecing as at the normal spinning, in a manner such that the spun yarn has fewer number of twists at the normal spinning than that at the time of yarn piecing. The rotor speed may also be simultaneously reduced as the speeds of the take-out and sliver supply are reduced.

Abstract: A method of making slub or thick and thin yarns with twist variation on open end spinning machines by changing the speed of the yarn as it exits from the rotor of the open end spinning machine. The method produces a unique slub yarn which has a portion of high twist adjacent the slub in the yarn which has lower yarn twist.