Abstract: The method of, and apparatus for, producing a yarn using a friction spinning device comprising a perforated first friction spinning drum and a second friction spinning drum which can also be perforated. Two fiber feed passages project to the first friction spinning drum and are each supplied by opening assemblies which individualize or individually separate the fibers. The fibers are transported toward the first friction spinning drum using a feed air stream in the fiber feed passages. This feed air stream is produced by the first friction spinning drum which is maintained under sub-pressure. Advantageously, the fiber double-feed to the friction spinning drum permits supplying two different fiber types to the same yarn end. Also, different inclinations of the fibers at the friction spinning drum can be obtained by different inclinations of the fiber feed passages in order to produce yarns of different character.

Abstract: A process is provided for operating open-end friction spinning machines of the type including movable friction surface parts defining a yarn forming region and a suction device for creating a suction effect on the yarn forming region. The process includes reducing the suction effect when spinning operations are interrupted, and interrupting the suction device at a point no later than the return of a yarn end into the yarn forming region. An apparatus for performing the process is also provided.

Abstract: An open end friction spinning apparatus is provided in which there are one or more spinning units with respectively two adjacently arranged rollers, rotating in the same direction, and disposed to form a wedge-shaped slot therebetween for accepting fibers and spinning them into a thread of yarn by a friction effect. Mechanical cleaning devices are provided for cleaning the surfaces of the rollers.

Abstract: A method of producing a twisted thread from spinning fibers by friction spinning includes moving two friction elements of a friction spinning machine in opposite directions defining a spinning wedge therebetween, at least one of the friction elements having a perforated wall, feeding spinning fibers into the spinning wedge in a given direction with a transporting air current, continuously withdrawing a twisted thread from the spinning wedge in the given direction, sucking a first part of the transporting air current through the perforated wall of at least one of the friction elements, and sucking a second part of the transporting air parallel to the spinning wedge, parallel to the thread and opposite to the given direction in which the thread is withdrawn and the fibers are fed into the spinning wedge, and a device for carrying out the method.

Abstract: A device for removing residual fibers from perforated friction surfaces of an OE-friction spinning machine includes a suction device including a controllable cut-off element connected to a suction source, a suction tube section connected between the cut-off element and the friction surfaces, and a controllable compressed air connection disposed in the suction tube section.

Abstract: A friction spinning device includes two drums being driven in the same direction and defining a wedge-shaped gap therebetween having a spinning region. A yarn draw-off device draws off yarn produced in the wedge-shaped gap in a given yarn draw-off direction. At least one of the drums is perforated and a suction device is disposed in the at least one drum and directed against the wedge-shaped gap. A fiber supply device has a fiber guide channel disposed at an angle relative to the given yarn draw-off direction. The fiber guide channel has substantially parallel side wall sections being mutually spaced apart by a given distance and the fiber guide channel has a slit-like fiber dispersion opening disposed in the wedge-shaped gap being delimited by the side wall sections and having a width substantially equal to the given distance. The fiber guide channel has a pipe-like enlargement at an end of the fiber dispersion opening being wider than the fiber dispersion opening.

Abstract: In an open-end friction spinning process provisions are made for the fibers to be fed tangentially onto the surface of a hollow friction roller, at an angle to the longitudinal axis of said roller, whereby the fibers reach the spinning wedge in this position. In this manner, the fibers are arranged at a predetermined angle as they go from the fiber feeding channel to the spinning wedge and are brought into contact with the yarn end in this position which facilitates the joining process.

Abstract: Apparatus for making a yarn comprises two juxtaposed, closely spaced apart twisting drums (1), which are adapted to be driven in the same sense, and an inclined fiber-guiding duct (4), which succeeds fiber-opening means (3) and protrudes into the generally triangular twisting space (2) between the two twisting drums (1) and serves to supply singled fibers in an entraining air stream to the generally triangular twisting space (2).In order to ensure a supply of properly oriented and uniformly distributed fibers into the generally triangular twisting space (2), the length (L) of the shortest boundary wall (5) of the fiber-guiding duct (4), which wall faces the generally triangular twisting space (2), is at least as large as the average length of the longest fibers to be processed in the apparatus, the ratio of the length (1) to the width (b) of the flow area is between 10:1 and 2:1, and the entraining air stream has a mean velocity of flow corresponding to a Reynolds number of 5,000 to 50,000.

Abstract: A piecing process is provided for an open-end friction spinning apparatus of the type including movable friction surface members forming a yarn-forming zone therebetween. A friction surface driving device for moving the friction surface members during operation and for interrupting the movement of the friction surface members is also included in the apparatus. The spinning apparatus further includes a yarn end orientation member for orienting a yarn end during the piecing process. The process includes placing a yarn end into the yarn-forming zone when the rollers are stopped. The friction surface members are started such that the yarn end is prevented from being pulled too deeply into the yarn-forming zone by the yarn end orientation device. An apparatus for carrying out this process is also provided.

Abstract: The mask sleeve within the perforated roller of each spinning unit of a multi-position friction spinning apparatus is adjustable to move the suction slot of that roller between extreme positions in which an edge of the slot crosses from one side of the friction spinning nip to the other. Adjustment at each spinning unit is effected independently of the various other units of the machine by means of a rotary adjuster engaging a bifurcated end of a carrier which is itself adjustably fastened (by way of a clamp bolt) with respect to the masking cylinder. The adjuster and the carrier are outside the machine and allow adjustment of the positioning of the slot deep within the spinning unit for fine tuning purposes.

Abstract: Vacuum spinning of yarn produces yarns having good properties, and which may have a wide variety of different effects and constructions. A core filament yarn may be fed into operative association with a nipped sliver or roving, and then fed to a perforated rotating hollow shaft operatively connected to the vacuum. The core filament yarn may be a full stretched textured yarn, which is placed under tension and while under tension is dragged over a sharp edge of nonconductive material, and after the tension is relieved develops crimp. This causes individual fibers to be repelled, and provides for intermixing of the nipped sliver or roving fibers and the core filament yarn fibers. Alternatively, the filament yarn may be acted upon by draft rollers before the entrance to, and after the exit from, the hollow rotating shaft, to apply a force that breaks up to about 20% of the fibers. The yarns produced utilizing the broken fibers has a spun-like appearance.

Abstract: An open-end spinning process in which the fiber sliver is separated into single fibers and in which the separated fiber material is brought by an air stream to a collecting surface from which it is drawn off while being twisted. According to the instant invention the fiber material is deposited on a collecting surface moving in the direction of thread draw-off, is then twisted and is continuously drawn off said collecting surface in form of a thread. The single fibers are fed upon the collecting surface in the direction of said collecting surface's movement, whereby an alignment of the fibers on the collecting surface takes place. The doubling process is separated from the spinning process as the fiber material is bundled and/or doubled on the collecting surface into a fiber sliver with the fiber mass required for the desired thread. The twisting process takes place independently of the collecting surface by means of a known twisting mechanism.

Abstract: A friction spinning unit includes a pair of cylindrical friction spinning rollers of which one has an air nozzle mounted adjacent to its periphery and able to discharge a current of air along the surface of that roller so as to move any unwanted fibres which may be on the surface of said roller. The air jet from the nozzle may provide a pneumatic barrier to hold fibres away from an annular passage between a surrounding shroud and the outer foraminous sleeve of the foraminous roller, and/or the air jet may be used to clear a fibrous slub from the spinning nip in the event of such a slub forming after a yarn break.

Abstract: The method for starting up a friction spinning assembly is used in a friction spinning assembly including: friction surfaces movable in opposite directions forming a spinning wedge, at least one of the friction surfaces being a perforated drum having a suction device with a suction nozzle acting on the spinning wedge by suctioning air through the wall of the at least one perforated drum; at least one suction device acting on the spinning wedge; and an automatic startup device performing a thread joining operation.

Abstract: An open-end friction spinning machine having a plurality of adjacently arranged spinning units is provided with one or more devices for conditioning the outer cylindrical surfaces of at least one roller of a roller pair contained in each spinning unit. Additionally, the spinning units are provided with one or more devices to monitor the friction characteristics of at least one of these rollers exhibiting a closed cover surface. The conditioning device is constructed so as to be responsive to a friction characteristic monitored by the friction characteristic monitoring device.

Abstract: An arrangement for open-end friction spinning is provided having a one-piece component fiber feeding duct that is mounted at an opening roller housing. The opening roller housing is held in a stationary position by a holding means containing a snap closure and the opening roller housing together with the fiber feeding duct can be removed for the exposure of the yarn-forming zone.

Abstract: Fibres are spun into yarn by being opened close to a surface (S, SD) and directed to the surface, conveniently by suction (AS) through the surface. A yarn or yarn end (Y) is twisted over the surface to have opened fibres built onto it to be spun into a twisted yarn. The surface can be a groove (GD) of included angle less than 90.degree.. The close spacing (WS) of a means to open the fibres and the surface can be such that fibres being opened are within reach of the surface. The yarn is twisted by a twister such as a parallel-belt twister (TB1/TB2) close to but not part of the surface. Tension (T) is applied through the twister to draw off yarn.

Abstract: Rotary twister element suitable to keep under tension the fibres during the twisting operation in a frictional open-end spinning process, constituted by a solid, hollow, reduced-thickness element with perforated skirt, which is internally provided with a suction duct defining a longitudinal slot, the edge of which constitutes the thread formation line, is suitably inclined relatively to the general trix of the same solid, hollow element, as a function of the direction of rotation of the solid element, and of the direction of thread extraction. Also a screen is provided for the air dragged by the rotation of the solid element, which may have a cylindrical shape, a cone frustum shape, or the shape of any other revolution solid.

Abstract: The perforated roller of a friction spinning unit includes an outer sleeve having vent openings at one end to provide an air leakage path which by-passes the adjacent bearing of the sleeve, and further by-passing vent passages radially outwardly of the bearing at the opposite end of the sleeve.

Abstract: In an open-end spinning device with two friction rollers driven in the same direction, located next to each other and forming a spinning nip, at least one of such friction rollers has a perforated casing which is over-mounted at one end. Such roller further contains a suction insert with a suction orifice connected to a negative pressure (i.e. vacuum) source. The perforated casing is supported on a shaft, one end of which is received and supported in a portion of the suction insert. The suction insert is located within the casing, directly behind it, and has a constant cross-section up to its connection with a suction line. In such manner, a maximum suction cross-section is provided with minimum support requirements.

Abstract: A friction open-end spinning process wherein the fibers of the feeding fiber sliver, once separated into discrete fibers, are sucked by a suction slot on a revolving twister element provided with a perforated surface, to feed the free end of the yarn being formed. The process is characterized in that the fibers are fed in a direction parallel to the free end of the yarn being formed, are kept under an adjustable tension throughout the twisting operation, and are subjected to a progressively increasing twist from the open end of the yarn being formed onwards. The device embodying the above process uses a revolving flat disc provided with perforations arranged according to an annulus as the twister element. This element cooperates with a sucking slot, the edge of which, consituting the yarn formation line, is positioned according to a chord of the disc.

Abstract: Apparatus for making a yarn comprises two juxtaposed, closely spaced apart twisting drums, which rotate in the same sense about parallel axes and at least one of which has a suction zone, which faces the generally triangular twisting space defined by said twisting drums between them. A fiber-guiding passage extends into said generally triangular twisting space at an oblique angle to the axes of said twisting drums and has an outlet opening, which extends along said axes and serves to supply fibers which are to be twisted together to form a yarn. In order to increase the strength of the yarn, each suction zone is enlarged in width adjacent to one end of the outlet opening of the fiber-guiding passage.

Abstract: The invention concerns an open-end spinning device with two friction rollers driven in the same direction and forming a spinning nip of which the roller rotating towards the spinning nip is a suction roller and in which the fibers fed into the spinning nip are twisted together into a thread in a yarn forming zone. At least one of the friction rollers (1, 2) is provided with a sector (I) subjected to negative air pressure in the spinning nip, in the range of the yarn forming zone (G). The width of said sector (I) extends, in the peripheral sense, from the yarn forming zone (G) to beyond the plane (A) connecting the axes of the friction rollers (1, 2) towards the side opposite to the spinning nip (3).

Abstract: The invention concerns an open-end spinning device with a release mechanism and two friction rollers in close proximity of each other, said friction rollers being driven in the same direction, wherein fibers are twisted together into a thread within the notch zone formed by said friction rollers, and furthermore concerns a thread draw-off device. According to the invention, the fibers are fed into the notch via a collecting surface moving parallel to the thread forming line. The collecting surface is located on the periphery of a disk-like cylinder, the rotational axis of said cylinder being located in a plane perpendicular to the notch. In a variant, the collecting surface is located on the surface of a disk or within a rotor in the form of an inner cone.

Abstract: The invention concerns and open-end spinning device having two friction rollers driven in the same direction and forming a spinning notch, whereby at least the friction roller rotating towards the spinning notch is made as a suction roller, conveying the fiber material fed onto its casing surface into the spinning notch. According to invention, a collecting groove for the arriving fiber material is provided at a distance from the spinning notch, said groove being constituted by the casing surface of the friction roller rotating towards the spinning notch and by a moving guiding surface. According to the invention the surface speed of the guiding surface in the collecting groove is synchronized with the surface speed of the friction roller.

Abstract: A friction spinning device has a pneumatic fiber transport passage or channel inclined at an angle to a perforated friction spinning element and a yarn formation position of the perforated friction spinning element is located at a spacing from an opening of the pneumatic fiber transport passage or channel. In such a friction spinning device, it is desired to ensure that the fibers located on the perforated friction spinning element are transported towards the yarn formation position neither parallel to nor at right angles to the yarn formation position. For this purpose, the perforations of the perforated friction spinning elements are so arranged that straight lines joining the perforation centers are disposed neither parallel to nor at right angles to the yarn formation position. In this way, fibers transported onto the perforated friction spinning element are laid on such perforated friction spinning element in the direction of the rows of perforations due to the intensity of the transporting air.

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: Spinning device for producing a twisted thread of spinning fibers, the device having two friction elements rotatable in the same rotary direction and with mutually parallel rotational axes, and a position varying device for permitting the friction elements to be brought temporarily into another position relative to one another for cleaning purposes and including constructive members in the position varying device for assuring constant parallelism of the rotational axes.

Abstract: In order to start or recommence spinning of a yarn in a friction spinning device, the following method steps are carried out upon start-up of a new spinning operation or upon piecing after a thread break: fibers separated by an opening device are delivered by means of a fiber transporting passage to a rotating friction spinning drum and are twisted to form a twisted fiber structure; when the twisted fiber structure has substantially reached a predeterminate diameter or size, then the twisted fiber structure is transported by an airstream delivered by a pressure duct towards and into a guide tube and is forwarded therein into a convergent space of rotating withdrawal rolls; and the twisted fiber structure is caught at production speed by these withdrawal rolls and delivered on a divergent side of the withdrawal rolls to a receiving suction device which transfers the spun yarn subsequent to the twisted fiber structure to further processing elements.

Abstract: In a friction-spinning process, the fibers (30) are twisted together on a thread formation line (43) as a result of the rotation of two friction elements (1, 10) driven in the same direction and forming a V-shaped nip and are drawn off as a thread (4). For piecing, the thread (4) is returned into the piecing position outside this thread formation line (43) and only then is placed in the thread formation line (43). During the run-off of the thread (4) from the friction elements (10), the pressing force of the thread (4) against at least one of the friction elements (10) is increased. For this purpose, a thread guide element (5) is arranged directly after the friction elements (10) and is movable transversely relative to the thread draw-off direction (42).

Abstract: An apparatus for open-end friction spinning is provided with at least one suction roller connected to a suction device. The suction device is connected via a valve with an underpressure or vacuum source which permits the adjustment and the switching off of the suction effect of the suction device. Adjusting elements operating independently of each other are respectively provided for switching off of the suction effect and for controlling the amount of the suction effect. These adjusting elements are operable by a moveable servicing apparatus.

Abstract: A friction roller for open end friction spinning and a method of making same are disclosed. The cover surface of the friction roller that imparts friction to fibers to form yarn in a yarn formation zone exhibits an outer surface texture which extends essentially in the longitudinal direction of the friction roller.

Abstract: Method of forming spinning fibers for producing a thread, which includes applying at least one laterally limited swarm of spinning fibers continuously to an outer cylindrical surface of a rotating, perforated drum having an interior, to which suction air is applied, further transporting the spinning fibers on the drum in peripheral direction of the drum along a spatial, spiral path wherein the spinning fibers are, respectively, accelerated, decelerated and individually separated from one another, clamping the spinning fibers at an outer end of the spiral path at a clamping line between the drum and at least one clamping element engaging the drum, and continuously conducting the spinning fibers away from the clamping line to at least one thread forming device.

Abstract: An arrangement for open-end friction spinning with two rollers forming a wedge-shaped gap is provided for separating the two rollers from a drive during a yarn breakage. A device reduces the speed of the roller rotating into the wedge-shaped gap earlier or faster than the roller rotating out of the wedge-shaped gap. Furthermore, a device is provided for switching off the suction device holding the producing yarn within the wedge-shaped gap during a yarn break.

Abstract: A friction spinning apparatus comprises a combing roller (19) for opening and feeding fibers in a duct (16, 15) to a throat (Q) formed between the outer surfaces of a pair of perforated and smooth surface drums (10, 12) arranged in parallel to each other and rotating in the same direction. A yarn (Y) formed at the throat (Q), by frictional contact between the fed fibers and the surfaces caused by a suction force, is withdrawn along the throat (Q). The duct (15, 16) is arranged to feed the fibers in an air stream having a direction inclined to the yarn axis (YL) and has a nozzle (17) in the form of a double pipe in the midportion thereof. A compressed air is ejected from the annular slit (17a) between the inner and outer pipe of the nozzle (17) to drag the fibers out from the nozzle (17) to cause them to stretch, whereby the fibers can be conveyed on the throat (Q) in the stretched state.

Abstract: In the making of a yarn, a stream of drawn core fibers (17a) is twisted in a triangular twisting space (4) between two juxtaposed, closely spaced apart twisting drums (1, 2), which are rotated in the same sense, and covering fibers are wound about said stream of fibers in said twisting space. To make said yarn from a single roving (17), the drawn roving (17) is fed to the twisting space (4) on the circumference of a feed roller (8), to which a vacuum is applied, the roving which has been fed on said feed roller is divided into two streams of fibers (17a, 17b) before reaching the twisting space (4), one (17a) of said streams of fibers is intended to constitute the core of the yarn to be made and is moved on the feed roller (8) as far as to the twisting space (4), and the other (17b) stream of fibers consists of the covering fibers and is detached from the feed roller (8 ) and its fibers are caused to fly freely into the twisting space (4).

Abstract: In the friction spinning of yarns, staple fibres are supplied to a yarn formation zone in which the yarns end is rotated by frictional contact with at least one twisting element. In the yarn form zone, a jet of air is applied to the yarn or forming yarn by nozzle to increase the frictional forces between the yarn or forming yarn and the twisting elements. The formed yarn is continuously removed from the yarn formation zone.

Abstract: The invention relates to an arrangement for open-end friction spinning having two adjacently arranged rollers driven in the same rotational direction and forming a wedge-shaped gap in which the yarn formation takes place. An air supply device is provided having at least one compressed air jet extending into the plane of the wedge-shaped gap and being directed upon the yarn for purposes of favorably influencing the contact force of the yarn against the rollers, and thereby the friction effect and/or the position of the yarn. In especially preferred embodiments, a plurality of compressed air jets are disposed to blow air against the yarn at positions downstream of the fiber feed in the yarn withdrawal direction. A suction device and a further compressed air jet are provided at the side of the wedge-shaped gap opposite the fiber feed opening in certain embodiments.

Abstract: An apparatus is disclosed for driving a pair of friction rollers arranged adjacent one another forming a wedge-shaped yarn-forming gap. A common drive belt is run along the surfaces of both rollers and the shaft of an electric motor. The motor is displaceably mounted in a guide which maintains the motor shaft in an essentially parallel relation to the friction roller shafts. The motor shaft can thereby be displaced for the purpose of increasing or decreasing the tension of the drive belt.

Abstract: A friction spinning apparatus includes a yarn winder and a pair of friction spinning rollers of which one is perforated and provided with a suction slot which is opened and closed on rotation of a piecing lever, means being provided for interconnecting operation of the piecing lever with, on the one hand, restoration of the winding operation and, on the other hand, restoration of fibre feed to the nip between the two friction spinning rollers.Preferably the interconnecting means comprise a pair of cams on the drive shaft linked to the piecing lever and co-operable with respective switches to control drive to the fibre feed roller of the fibre-opening unit and also the package lift mechansim to initiate winding.

Abstract: In a method and an apparatus for producing a yarn by means of friction spinning drums, a fiber sliver is drawn by a drafting mechanism to a body of fibers and transferred to a first perforated friction spinning drum of such friction spinning drums. At this first perforated friction spinning drum, the fibers are entrained by a suction air stream, produced by a suction passage located in the first perforated friction spinning drum, and are then fed into a converging space formed by and between the friction spinning drums. In this converging space the fibers are twisted into a spun yarn. The spun yarn is withdrawn by withdrawal rollers located near end faces of the friction spinning drums. The suction air stream required for entraining or catching the fibers is limited by walls forming the suction passage. The advantage of this apparatus is that the fibers are mechanically guided over the whole length of their travel path, i.e. from the body of fibers to the twisted yarn.

Abstract: The apparatus comprises a stretching unit (S) delivering two stretched fiber rovings (4, 5). One fiber roving (4) serves as the core for the wrapped yarn to be produced and runs to a twist-imparting device (6, 7). The fibers of the other fiber roving (5) are transferred to a moving fiber feeding and holding surface (9) constituted by a perforated peripheral surface of a hollow disk (10). This surface (9) comes into contact with the core (4) at a point (C) in front of the twist-imparting device (6, 7). At this contact point (C), the fibers fed on the surface (9) are seized by the rotating core (4) and wound up. At the contact point (C), a fiber catching device (12) is likewise arranged, having an air-permeable surface (11) behind which a vacuum is maintained.

Abstract: A device is provided for open-end friction spinning having two adjacently arranged rollers serving to form a yarn forming wedge-shaped gap. The rollers are disposed in essentially a vertical direction. A supply of fibers is directed through a fiber feed channel extending at a sharp angle from underneath the rollers to the wedge-shaped gap. The withdrawal device for the spun yarn is disposed above the rollers. Between the wedge-shaped gap and the withdrawal device there is arranged a turning guide which first withdraws the yarn opposite the feeding direction in the longitudinal direction of the wedge-shaped gap and then turns the yarn and withdraws it to the withdrawal device disposed above.

Abstract: An arrangement is provided for open-end friction spinning including a pair of adjacently arranged suction rollers rotatable in the same rotational direction. One roller rotates into the wedge-shaped gap formation zone and the other rotates out of the wedge-shaped gap. It is provided that the suction slot of the suction insert inside of the roller rotating into the wedge-shaped gap is longer than the suction slot of the suction insert of the roller rotating out of the wedge-shaped gap. The portion of the suction slot of the roller rotating into the yarn formation zone which extends beyond the slot of the roller rotating out of the yarn formation zone is displaced circumferentially from the wedge-shaped gap so as to provide for enhanced spinning conditions in the region of the yarn tip.

Abstract: A fiber feed channel of an open-end spinning apparatus is divided by a parting face into a stationary part and a movable part, including a pivoted cover. The parting face includes an elastic O-ring, the surface of which is disposed at a predetermined minimum angle .alpha. relative the direction of movement of the pivoted cover. Such orientation ensures a relatively perpendicular component of contact between the O-ring and the pivotal cover, thereby reducing sliding friction between the two which prolongs the life of the O-ring while providing a good seal. Two interacting elements, one arranged on the cover and the other arranged on the spinning element housing, define a stop for positioning the cover relative to the spinning element.

Abstract: Friction spinning apparatus comprises a fibre feed duct having a secondary suction port which is linked to a source of suction by way of a second perforated region of the perforated roller. The secondary air passage is communicated to a source of suction by way of the second perforated region having a suction opening formed in a masking sleeve therewithin. Yet a further masking sleeve radially inwardly of the first has two differently sized holes for changing the volume of air flowing through the hole and hence changing the airflow rate through the secondary air passage.The secondary air passage can be relatively large in cross-section and the flow constriction of the secondary air path can be by way of the second perforated region of the roller which is self-cleaning and hence avoids blockage of the secondary air path.

Abstract: In a friction spinning device comprising a fiber opening assembly, a fiber feed passage arrangement, and friction spinning drums cooperating with the fiber feed passage arrangement, the fiber feed passage arrangement is divided in its longitudal direction into two passage or channel halves. At the separation or parting joints or gaps formed by connection flanges associated with the passage halves, there can be provided recesses so that a respective connecting slot is formed between the cross-section of the fiber feed passage arrangement and the separation or parting joints. In this way, there can be substantially avoided contact of fibers with the separation or parting joints.

Abstract: A device for feeding-in a thread end through a thread draw-off channel of a thread guiding element into a spinning nip of a friction spinning device includes a pressurized-gas injection device in the thread guiding element for producing an air flow in the thread draw-off channel opposite in direction to that of a thread draw-off direction of a spinning operation in the friction spinning device, whereby a thread end is entrained thereby, the thread draw-off channel continuing along the spinning nip from a termination thereof in the thread guiding element.

Abstract: A friction spinning frame including a pair of twisting rollers disposed substantially in parallel and driven in the same direction to each other at a small gap therebetween to form a yarn forming zone of a valley shaped profile on upper surfaces of the twisting rollers along the gap. At least one of the twisting rollers is a perforated hollow roller including an outer shell having a plurality of perforations on the entire outer surface thereof and a suction device for providing a suction force through the perforations, whereby staple fibers are twisted to form a yarn while being sucked and held on the yarn forming zone.

Abstract: An open end friction spinning machine is disclosed which includes plurality of adjacently arranged spinning units which each have a pair of friction rollers forming a yarn twisting wedge slot. To accommodate cleaning of the friction rollers a mobile servicing cart is provided which is movable longitudinally along the machine to respective servicing positions adjacent spinning units to be cleaned. The servicing cart includes cleaning elements engageable with the rollers to clean them and air suction and blowing devices to assist in the cleaning and removal of contaminants.