EP0602229B1 - Process and device for open-end spinning - Google Patents

Abstract

In open-end spinning, the fibres from a release device are taken, after leaving a fibre feed channel (3), to a fibre guide surface (10) and then to a fibre collection groove (11) of a rotating spinning rotor (1) in which the fibres are laid and spun into the end of a continuously drawn-off thread. In this spinning process the fibres emerging from the fibre feed channel (3) are first compressed substantially in a plane and thus broadened in the direction of rotation of the spinning rotor (1) and then fed on a part of the periphery of the spinning rotor (1) as a thin ucil. To implement this process, the wall of the last longitudinal section (30) arranged in the extension of the penultimate longitudinal section (31) of the fibre feed channel (3) takes the form of a fibre distribution surface (300) extending substantially perpendicularly to the plane defined by the centre lines (310, 301) of said two longitudinal sections (31, 30). Here, the longitudinal section (30) of the fibre feed channel (3) opens into a radial slot (6) having a fibre extending surface (60) reaching the fibre guide surface (10) and lying opposite the fibre distribution surface (300).

Description

The present invention relates to a method for open-end spinning according to the preamble of claim 1 and an open-end spinning device according to the preamble of claim 7.

An open-end spinning device according to the preamble of claim 1 is known from EP-A 301 581, for example from FIG. In addition, it is also shown that the fibers are first fed onto a surface before they reach the wall of the spinning rotor.

In a known open-end spinning device, to adapt to different rotor diameters, the fiber feed channel is divided into several longitudinal sections arranged at an angle to one another (DE 37 34 544 A1), but without taking special measures to optimize the fiber placement on the fiber collecting surface of the spinning rotor. The consequences of this are different yarn qualities, depending on the rotor diameter and the deflections of the fibers selected as a result.

It is therefore the task of the inventors to improve the feeding of the fibers into the spinning rotor, so that the disadvantages shown are avoided and high quality yarns are produced.

This object is achieved in a method for open-end spinning, in which the fibers coming from a disintegration device are fed via a fiber feed channel to a fiber guide surface of a spinning rotor, placed in a fiber collecting groove of the spinning rotor and then spun into the end of a continuously drawn thread in that the Fibers are compressed on a fiber distribution surface before leaving the fiber feed channel and thereby spread out and then reach the outlet mouth of the fiber feed channel and are fed onto the fiber guide surface as a thin veil.

By compressing the fiber stream it is achieved that the fibers are deposited essentially on a height line of the sliding wall of the spinning rotor, on which they slide along, in order finally to get into the fiber collecting groove. In addition, the fiber stream is spread in the direction of rotation, the speed being reduced. The air which is deflected in the spinning rotor's open edge is thus slowed down, so that its influence on the fibers diminishes and the risk that fibers are entrained by the air and removed via the open rotor edge is substantially reduced. The spreading of the fibers prevents the trajectories of the fibers leaving the fiber feed channel from crossing, so that this type of fiber feed can achieve a much more orderly fiber placement on the sliding wall.

It is preferably provided that the fibers are spread out along a contour line which runs parallel to the plane through the fiber collecting groove.

In principle, the fibers of the sliding wall can also be fed along a conical surface upstream of the sliding wall. In this way, the air must be deflected very strongly for its removal, so that a particularly good separation of fibers and air is achieved. A simpler construction and a more precise feeding of the fibers onto the sliding wall can, however, be achieved according to the invention by compressing and spreading out the fibers emerging from the fiber feed channel before they are fed as a thin veil onto the fiber guide surface of the spinning rotor.

The fibers are preferably fed to the sliding wall of the spinning rotor in the vicinity of the open rotor edge. Surprisingly, it has been shown that an optimization of the yarn values is achieved in this way.

It has been found that it can be advantageous to improve the spreading of the fibers if the fibers emerging from the fiber feed channel are exposed to a bundled air flow.

Particularly good spinning results are achieved if, according to the invention, the air emerging from the fiber feed channel is inevitably directed into the vicinity of the sliding wall of the spinning rotor.

The object on which the invention is based is achieved in terms of the device in an open-end spinning device according to EP-A 301 581 with a spinning rotor and a fiber feed channel which has at least two longitudinal sections, the center lines of which are arranged at an angle to one another and of which the last longitudinal section in the fiber transport direction is opposite a fiber guide surface of the spinning rotor ends, solved in that the wall of the last length section arranged in the extension of the penultimate length section of the fiber feed channel is designed as a fiber distribution surface which extends essentially perpendicular to the plane defined by the center lines of the two mentioned length sections, such that the fibers are due to their Centrifugal force is thrown onto the fiber distribution surface and can be spread there, then along the fiber distribution surface to the outlet mouth of the fiber feed channel and as a thin veil on the fiber guide surface can be stored. Through this spread the risk that the fibers interfere with each other during their transport into the spinning rotor is reduced. This leads to more even yarns with higher strength.

Depending on the width of the fiber distribution surface and its arrangement with respect to the preceding length section of the fiber feed channel, it is particularly advantageous to design the fiber distribution surface as a flat surface, but it has been shown that, particularly in the case of small widths or small deflection angles, the fiber propagation can also be promoted in that Fiber distribution surface is designed as a convex surface.

It is preferably provided that the fiber distribution surface widens more and more with increasing distance from the penultimate length section of the fiber feed channel.

In an expedient embodiment of the subject matter of the invention it can be provided that the length of the fiber distribution surface is at most as large as the average stack length of the fibers that are being spun. In this way, despite favorable fiber propagation, it is prevented that the fibers sliding along the fiber distribution surface are slowed down too much. In order to counteract such a braking effect, it can advantageously be provided that the outlet mouth of the fiber feed channel tapers along said plane.

In order to optimize the desired fiber propagation effect, it is provided in an expedient development of the subject-matter of the invention that the fiber distribution surface is arranged relative to the penultimate length section of the fiber feed channel in such a way that the axial projection of the penultimate length section of the fiber feed channel falls entirely on the fiber distribution surface of the fiber feed channel.

The fiber guide surface to which the fibers are fed can be part of a guide funnel which projects into the open side of the spinning rotor. Advantageously, however, the fiber guide surface is part of the spinning rotor and is formed by its inner wall.

In order to avoid fiber compression, the angle between the two mentioned longitudinal sections of the fiber feed channel should not be too large. It has been shown that good results are achieved if the last two longitudinal sections of the fiber feed channel form an angle between 10 ° and 30 °.

In order to be able to feed the fibers to the center of the fiber distribution surface so that an optimal fiber distribution is achieved, it is advantageous if the center lines of all the length sections lie in one and the same plane.

It has been shown that an intensification of the fiber distribution in the circumferential direction of the spinning rotor can be achieved in that the last longitudinal section of the fiber feed channel opens into a radial slot which has a fiber spreading surface which extends to the fiber guide surface and is opposite the fiber distribution surface.

In a further embodiment it is provided that the recess is designed as a radial slot, the height of which - measured parallel to the rotor axis - in the region of its outlet mouth is smaller than the height of the fiber feed channel and which extends over a substantial part of the circumference of the spinning rotor. In this way it is achieved that the fibers of the sliding wall are fed as a thin veil and the air is safely separated from the fibers.

It is preferably provided that the height of the outlet opening of the radial slot is lower for small yarn numbers than for coarse yarn numbers.

This makes it possible to always provide an optimal slot depending on the fiber throughput.

In a preferred embodiment of the device according to the invention, in order to achieve a particularly narrow fiber veil, the arrangement of the outlet mouth of the fiber feed channel with respect to the radial slot is such that the projection of the last length section of the fiber feed channel is fully into the fiber spreading surface opposite the fiber feed channel of the radial slot falls.

In principle, the slot can taper from the point at which the fiber feed channel opens into the outlet mouth, but it has been shown that particularly good spinning results are achieved if the radial slot has two parallel guide surfaces which intersect the rotor axis at a distance from one another. It is particularly advantageous if the two guide surfaces run parallel to the plane laid through the fiber collecting groove.

So that the fibers have to cover the longest possible sliding path from the feed line to the fiber collecting groove, which has an advantageous effect on the fiber stretching, it is provided according to a preferred embodiment of the subject matter that the radial slot opens into the vicinity of the open edge of the spinning rotor. It has proven to be advantageous if the distance - measured parallel to the rotor axis - of the guide surface of the radial slot, which faces away from the plane through the fiber collecting groove, from the open edge of the spinning rotor is at least one third of the height of the outlet opening of the radial slot.

For a good spreading of the fibers in the direction of rotation, a long slot is required in relation to the rotor circumference. According to the invention, this therefore extends over at least half the rotor circumference. The radial slot is expediently delimited in front of and behind the outlet mouth of the fiber feed channel by side walls which extend essentially parallel to the rotor axis and radially up to near the sliding wall of the spinning rotor.

It has been shown that it can be advantageous under certain operating conditions if - in the direction of rotor rotation seen - the radial slot begins at a distance before the fiber feed channel opens into the radial slot.

In order to achieve a substantial reduction in air speed in addition to good fiber propagation, it can be provided in a further advantageous development of the device according to the invention that the outlet cross section of the radial slot is a multiple of the cross section of the inlet mouth of the fiber feed channel into the radial slot.

The radial slot is preferably delimited either by two substantially straight side walls, which are connected to one another by a convex surface, or by convex side walls with changing convexity. In the latter case, according to an advantageous embodiment of the subject matter of the invention, the convexity increases substantially up to the outlet mouth of the fiber feed channel and then decreases again.

In order to avoid air turbulence, which has an adverse effect on the fiber transport to and the fiber deposition on the sliding wall of the spinning rotor, it is expedient if the side walls of the radial slot merge into a connecting wall running concentrically to the rotor axis.

Outside the area of the radial slot into which the fiber feed channel opens, a boundary is preferably provided which forms the side walls of the radial slot and, according to the invention, extends over the area which is arranged diametrically with respect to the rotor axis with respect to the outlet mouth of the fiber feed channel. This slot limitation can be more or less as desired, both before and after the outlet mouth of the fiber feed channel - based on the direction of rotation of the spinning rotor extend far towards the outlet mouth of the fiber feed channel.

It has been shown that, under certain operating conditions, particularly good spinning conditions are achieved if — seen in the direction of the rotor rotation — an air duct opens into the radial slot from behind. It can be provided that the air duct between its inlet opening opposite the fiber guide surface and the opening of the fiber feed channel into the radial slot is separated by a wall from the interior enclosed by the fiber guide surface.

In order to be able to subsequently implement the invention on machines that have already been delivered, it can be provided that the radial slot is delimited in the axial direction and laterally by an exchangeable element.

In order to prevent fibers from getting stuck on separation gaps between the exchangeable element and its rotor lid, which serves as a carrier, such separation gaps are arranged according to the invention outside the fiber flight area.

This expediently takes place in that the exchangeable element rests on the end of the radial slot facing the fiber feed channel against a rotor lid which covers the spinning rotor and at least the last length section of the fiber feed channel with the first fiber distribution surface. It can be provided according to an advantageous embodiment of the subject matter of the invention that the exchangeable element is pushed onto a part receiving a thread take-off channel.

According to an alternative advantageous development of the device according to the invention, it is advantageously provided that the side walls delimiting the radial slot their side facing away from the radial slot enclose between them a web with which the part of the exchangeable element which has the second fiber distribution surface is connected to a fastening part which extends radially outwards and is arranged in a recess in the rotor housing cover and is connected to the rotor housing cover. To achieve a simple construction, the fastening part expediently has radial walls which are arranged in an extension of the side walls delimiting the radial slot.

In order to prevent the circumferential fibers from getting caught, it is advantageously provided that the radial walls of the fastening part and the walls of the recess adjacent to the radial walls have rounded edges on their side facing the spinning rotor.

As mentioned, it is advantageous if the height of the outlet opening of the radial slot is adapted to the yarn number. This can be done by arranging the radial slot in an exchangeable part. According to another advantageous embodiment of the device according to the invention it is provided that the height of the radial slot is adjustable. In this case, a spacer of the desired thickness can be used to fix the set height between a fastening part of an element delimiting the radial slot in the axial direction and a part carrying this element.

The radial slot is expediently axially through a. Element limited, which has at least one extending in the axial direction, cooperating with a counter wall and which is axially adjustable by means of an actuator.

Around the exchangeable element in a precisely defined position relative to the part carrying this exchangeable element, e.g. To fix the rotor housing cover and at the same time to close the separation points between the exchangeable element and the part carrying this element so that no fibers can get caught, it can be provided that the exchangeable element is connected to the part carrying this element by means of such a connecting element which exerts pressure towards the cooperating guide walls of the interchangeable element and the part carrying this element.

The device according to the invention is simple in construction and can also be retrofitted in open-end spinning devices, for which the exchange of the rotor cover covering the spinning rotor is generally sufficient. The fibers fed to the spinning rotor are spread out in the circumferential direction of the spinning rotor and fed to the fiber guide surface in the form of a more or less wide fiber veil. Fiber propagation reduces the risk of mutual fiber impairment. The frequency of fiber accumulations and fiber tangles is reduced. Due to the fiber spreading, the fibers are deposited essentially at a defined distance from the fiber collecting groove, so that the slideways of the fibers sliding along the fiber guide surface to the fiber collecting groove do not cross. This leads to a further improvement in the fiber placement in the fiber collecting groove of the tension rotor. The optimized fiber placement on the fiber guide surface also reduces the risk of free-flying fibers that could be caught and bound by the thread in the take-off without first being placed in the fiber collecting groove. The result of this optimized fiber placement is a yarn of high uniformity, increased strength and greater elasticity. Other values that determine yarn quality will also be improved by the subject of the invention, especially in fine yarns.

Figur 1

im Längsschnitt einen Offenend-Spinnrotor sowie einen Teil eines Rotordeckels mit einem erfindungsgemäß ausgebildeten Faserspeisekanal;

Figur 2 bis 4

verschiedene erfindungsgemäße Ausbildungen des letzten Längenabschnittes des Faserspeisekanals im Querschnitt;

Figur 5

im Längsschnitt einen Faserspeisekanal gemäß der Erfindung;

Figur 6

im Querschnitt eine Abwandlung der gemäß der Erfindung ausgebildeten Offenend-Spinnvorrichtung;

Figur 7

im Längsschnitt eine weitere Abwandlung eines erfindungsgemäß ausgebildeten Faserspeisekanals;

Figur 8

eine andere erfindungsgemäß ausgebildete Offenend-Spinnvorrichtung im Querschnitt;

Figur 9 und 10

ein Detail der in Figur 8 gezeigten Vorrichtung in unterschiedlicher Ausbildung im Querschnitt;

Figur 11 bis 14

einen Deckelansatz im Schnitt mit unterschiedlichen erfindungsgemäß ausgebildeten Radialschlitzen;

Figur 15

einen wenigstens teilweise in einem Adapter angeordneten, erfindungsgemäß ausgebildeten Radialschlitz;

Figur 16 und 17

in der Draufsicht bzw. im Querschnitt einen Rotorgehäusedeckel mit einem erfindungsgemäßen Radialschlitz; und

Figur 18 und 19

im Querschnitt in verschiedenen Breiten einen Radialschlitz gemäß der Erfindung; und

Figur 20

einen Deckelansatz im Schnitt mit einem Luftführungskanal.

Exemplary embodiments of the subject matter of the invention are explained in more detail below with the aid of drawings. Show it:

Figure 1

in longitudinal section an open-end spinning rotor and part of a rotor lid with a fiber feed channel designed according to the invention;

Figure 2 to 4

different designs of the last length of the fiber feed channel according to the invention in cross section;

Figure 5

in longitudinal section a fiber feed channel according to the invention;

Figure 6

in cross section a modification of the open-end spinning device designed according to the invention;

Figure 7

in longitudinal section a further modification of a fiber feed channel designed according to the invention;

Figure 8

another open-end spinning device designed according to the invention in cross section;

Figures 9 and 10

a detail of the device shown in Figure 8 in different training in cross section;

Figure 11 to 14

a lid approach in section with different radial slots designed according to the invention;

Figure 15

an at least partially arranged in an adapter, designed according to the invention radial slot;

Figures 16 and 17

in plan view or in cross section a rotor housing cover with a radial slot according to the invention; and

Figure 18 and 19

in cross section in different widths a radial slot according to the invention; and

Figure 20

a lid approach in section with an air duct.

The invention will first be explained with the aid of FIGS. 1 and 8, which only show the elements relevant for the explanation of the invention.

FIG. 8 schematically shows an open-end spinning device which, in a known manner, consists of a feed device 7, a dissolving device 72, a rotor housing cover 2, a rotor housing 13 and a take-off device 8.

The feed device 7 is in the embodiment shown from a delivery roller 70 with which a feed trough 71 cooperates elastically.

The opening device 72 has a housing 73 in which a opening roller 74 is arranged.

The rotor housing cover 2 covering the open side of the spinning rotor 1 receives a fiber feed channel 3, the beginning 75 of which is arranged in the housing 73 of the opening device 72. The fiber feed channel 3 ends in a cylindrical or conical projection 20 which projects centrally into a spinning rotor 1 arranged in the rotor housing 13. The projection 20 receives a thread take-off channel 4 coaxially with the spinning rotor 1.

The rotor housing 13 is connected by means of a line 14 to a vacuum source, not shown, which generates a vacuum in the spinning rotor 1 during operation. The spinning rotor 1 has a fiber guiding surface 10 designed as a sliding wall, which extends from the open edge 12 of the spinning rotor 1 to a fiber collecting groove 11.

During normal spinning operation, the opening roller 74 feeds a fiber sliver 9, which dissolves this sliver 9 into individual fibers 90, which are introduced into the spinning rotor 1 by means of a fiber / air flow, from which the fibers 90 then separate and along the inner wall of the spinning rotor 1 forming a sliding wall and fiber guide surface 10 slide into the fiber collecting groove 11 thereof. The fibers 90 collect there and form a fiber ring 91, which is integrated in the usual way into the end of a continuously drawn thread 92, which leaves the spinning rotor 1 through the thread take-off channel 4 and is wound onto a spool (not shown).

It is usually provided that the fibers 90 leave the fiber feed channel 3 in the form of a bundled fiber / air stream which is directed against the fiber guide surface 10. The fibers 90 usually assume a random position within the fiber feed channel 3 or are collected on one of the concavely curved inner sides of the fiber feed channel 3 in accordance with the geometry of the fiber feed channel 3. The fibers 90 thus leave the fiber feed channel 3 with respect to the spinning rotor 1 at different heights (along the fiber guide surface 10) and therefore, when sliding down along the fiber guide surface 10, reach the region of slideways of other fibers 90. The result is that the fibers 90 separate hinder each other in sliding down into the fiber collecting groove 11. The same is the case when the fibers 90 reach the fiber guide surface 10 of the spinning rotor 1 in a bundled flow.

In order to remedy this disadvantage, it is provided according to FIG. 1 that the fibers 90 are placed on the fiber guide surface 10 of the spinning rotor 1 in such a way that the paths of the individual fibers 90 do not interfere. This is achieved in that the fibers 90 before they leave the fiber feed channel 3 are spread along this along a contour line - parallel to the plane defined by the collecting groove 11 - and are fed in this form to the fiber guide surface 10 of the spinning rotor 1. In this way, the fibers 90 slide along spiral-shaped, spaced-apart tracks along the fiber guide surface 10 into the fiber collecting groove 11.

In order to extend the fibers 90 in the circumferential direction of the spinning rotor 1 parallel to a height line of the spinning rotor 1, it is provided that a wall of the fiber feed channel 3 forming a fiber distribution surface 300 extends along a height line of the spinning rotor 1 in the outlet region thereof.

The fibers 90 must be fed to this fiber distribution surface 300 and compressed so that they are fed along this to the spinning rotor 1. In order to achieve this, as shown in FIG. 1, it is provided that the second last part (penultimate length section 31) of the fiber feed channel 3 and the last part (length section 30) of the fiber feed channel 3 are arranged at an obtuse angle α to one another such that the extension 311 of the center line 310 of the penultimate length section 31 of the fiber feed channel 3 intersects the fiber distribution surface 300 of the last length section 30 of the fiber feed channel 3.

This fiber distribution surface 300 of the last length section 30 of the fiber feed channel 3 is arranged essentially perpendicular to the image plane (plane E in FIG. 5), which is laid through the center lines 301 and 310.

The fibers 90, which reach the fiber feed channel 3 from the opening roller 74 in a known manner, are thrown due to their centrifugal force in the direction of the fiber distribution surface 300, which extends essentially transversely to the previous fiber transport direction. As a result of this centrifugal effect, the fibers 90 are compressed and spread out in one plane, ie on this fiber distribution surface 300, and now pass along this fiber distribution surface 300 to the outlet opening 302, where the fibers 90 leave the fiber feed channel 3 in the form of a fine fiber veil. The transport air is deflected sharply in a known manner in order to leave the spinning rotor 1 between the open edge 12 and the rotor lid 2. The fibers 90, on the other hand, are thrown against the inner wall (fiber guiding surface 10) of the spinning rotor 1 due to their inertia, whereby they reach this fiber guiding surface 10 essentially on one and the same contour line - parallel to the plane defined by the collecting groove 11 - due to the fiber propagation previously carried out. As before mentioned, the fibers 90 can now slide along parallel paths in the fiber collecting groove 11 of the spinning rotor 1 without interfering with one another.

As a result of this unimpeded and undisturbed sliding of the fibers 90 into the fiber collecting groove 11, the fibers 90 are deposited evenly in the fiber collecting groove 11 and thus also form a uniform fiber ring 91. This has the consequence that the thread 92 which is formed is also uniform. This not only leads to a reduction in the otherwise usual irregularities in the thread 92, but also leads to an increase in the tensile strength. Other yarn properties such as elasticity etc. are also improved.

The device described can be modified and configured in a variety of ways within the scope of the present invention, for example by replacing individual features with equivalents or through other combinations thereof. For example, the fiber distribution surface 300 of the fiber feed channel 3 can be designed in various ways. Figure 2 shows an embodiment of the cross section of the last length section 30 of the fiber feed channel 3, in which the fiber distribution surface 300 essentially as a flat surface, i.e. is designed as a flat surface. According to FIG. 4, this fiber distribution surface 300 is also essentially designed as a flat surface, but this time the cross section of this length section 30 is not designed as a partial circular surface, but essentially as a rectangular surface.

FIG. 3 shows a modification of this fiber distribution surface 300, which is designed as a convex surface. The fiber / air flow is directed against the fiber distribution surface 300 in such a way that it reaches this fiber distribution surface 300 essentially in the plane E. The fiber stream now spreads out to the side, this spreading accelerating due to the convex curvature becomes. Such a distribution surface is therefore particularly advantageous if only a short path is available within the last length section 30 of the fiber feed channel 3 for fiber distribution.

FIG. 5 shows a longitudinal section through a fiber feed channel 3, the section running along the center lines 310, 301 (FIG. 1) perpendicular to the image plane. As can be seen from this, the length section 31 tapers in the usual way up to the transition 32 into the last length section 30. This last length section 30 tapers along the drawing plane (plane E) of FIG. 1, but widens along the drawing plane of FIG. 5, see above that the fiber distribution surface 300 also widens with increasing distance from the penultimate length section 31, so that the fibers 90 can spread out to the outlet mouth 302 of the fiber feed channel 3.

It has been shown that the fiber guiding surface formed by the fiber distribution surface 300 should not be too long. The length a of this fiber distribution surface 300 in the fiber transport direction should be at most as long as the length (average staple length) of the fibers 90 that are being spun.

On the other hand, the fiber distribution area should not be too short so that it can effectively spread the fibers 90. It has proven to be expedient to design and arrange the two length sections 31 and 30 of the fiber feed channel 3 so that not only the extension of the center line 310 intersects the fiber distribution surface 300, but that the entire projection of the penultimate length section 31 onto the fiber distribution surface 300 of the last one Longitudinal section 30 falls.

The sliding wall of the spinning rotor 1 forms a fiber guide surface 10, onto which the fibers 90 leaving the fiber feed channel 3 are fed. However, it is not necessary that the fibers 90 leaving the fiber feed channel 3 are fed directly to the spinning rotor 1 and that the fiber guide surface 10 is part of the spinning rotor 1. Rather, it is also quite possible that the fibers first reach a fiber guide surface (not shown) which is independent of the spinning rotor 1 and ends in such a way that the fibers moving along this fiber guide surface reach the sliding wall (second fiber guide surface 10) of the spinning rotor 1 to slide into the collecting groove 11.

The deflection of the fiber feed channel 3 at the transition from the length section 31 to the length section 30 should not be too great. Optimal results could be achieved at an angle α between the two longitudinal sections 31 and 30 of the fiber feed channel 3 between 10 ° and 30 °.

A design according to which the fiber stream has not yet been bundled along a wall of the fiber feed channel 3 oriented parallel to the image plane before the length section 31 of the fiber feed channel 3 has been reached can also contribute to this optimization. For this reason, according to FIG. 5, the center lines 310, 301 of all the length sections - thus also the center lines of the length sections preceding the length sections 31 and 30 - of the fiber feed channel 3 are arranged in one and the same plane E. In this way, the fibers 90 maintain their original direction in the fiber feed channel 3. A deflection within the plane E preceding the angle α, on the other hand, is irrelevant for the fiber propagation and, with a corresponding shaping of the fiber feed channel 3, can even promote the fiber propagation.

According to a training that can also be easily retrofitted A fiber feed channel 3 of the type described can be provided that an insert plate 5 is inserted into an existing rotor lid 2, which extends transversely to the plane E fixed by the center lines 301 and 310. The insert plate 5 thus forms the fiber distribution surface 300 with its area projecting into the interior of the fiber feed channel 3. The length section of the fiber feed channel 3, into which the insert plate 5 projects, forms the last length section 30 of the fiber feed channel 3, while the preceding length section thus forms the penultimate length section 31 forms. The fiber feed channel 3 per se, ie without taking the insert plate 5 into account, can have a straight course in the region of these two longitudinal sections 30 and 31. It is also achieved here that the fibers 90 spread on the fiber distribution surface 300 of the fiber feed channel 3 and reach the fiber guide surface 10 of the spinning rotor 1 in the form of a fiber veil. Due to the strong air flow that leaves the fiber feed channel 3 at its outlet mouth 302, the fibers 90 are immediately oriented in the radial direction with respect to the spinning rotor 1 when leaving the fiber feed channel 3, so that the fibers 90 in this direction and thus practically in a radial plane the fiber guide surface 10 (sliding wall) of the spinning rotor 1 are supplied. The advantages are therefore the same as described previously.

FIG. 6 shows a further modification of the device described, in which the fiber feed channel 3 or its last length section 30 opens into a narrow radial slot 6, which ensures that the fibers 90, which leave the fiber feed channel 3, in the radial direction of the peripheral wall (fiber guide surface 10 ) of the spinning rotor 1 are fed. This radial slot 6 has a fiber spreading surface 60 opposite the fiber distribution surface 300, which extends in the direction of the fiber guide surface 10 of the spinning rotor 1 or to another fiber guide surface (not shown), which is arranged in the fiber transport direction in front of the spinning rotor 1. The fibers are fed in the form of a fiber veil to this fiber guide surface 10, which compresses and spreads these fibers 90 a further time and thus widens the fiber veil in the circumferential direction of the spinning rotor 1. The consequence is a further intensification of the spreading of the fibers 90 and thus the basis for a further improvement of the fiber placement in the collecting groove 11 of the spinning rotor 1.

6 it is provided that the fiber feed channel 3 opens into a radial slot 6. As shown in FIG. 15, it is not an unconditional requirement that in addition to the fiber spreading surface 60 there is another fiber distribution surface 300 preceding it, but the combination of a fiber distribution surface 300 and a fiber spreading surface 60 is particularly advantageous in the case of cramped space conditions, i.e. with small rotor diameters, since the fiber distribution surface 300 collects the fibers 90 and, with respect to the axial extent of the spinning rotor 1, feeds them as a compressed veil to the fiber spreading surface 60, which compresses the fibers 90 again with respect to the axial extent of the spinning rotor 1 and continues the spreading of the fibers 90. In this way, the fibers 90 are distributed as a thin veil over a large area of the spinning rotor 1.

It is often sufficient, as already indicated above, if only one fiber distribution surface 300 or one fiber spreading surface 60 is provided. After a design with the fiber distribution surface 300 provided in the fiber feed channel 3 has already been described above, a design will now be described in which only one fiber spreading surface 60 is provided as part of a radial slot 6 (FIGS. 8 and 11).

This radial slot 6 is in turn provided in the projection 20 of the rotor housing cover 2, into which the fiber feed channel 3 opens and the outlet opening 61 thereof is directed against the fiber guide surface 10 of the spinning rotor 1. The radial slot 6 is - seen parallel to the rotor axis 15 - delimited by a first fiber guiding surface forming a fiber spreading surface 60 and a second guiding surface 62.

Figure 11 shows a section through Figure 8 along the plane IV-IV. As a comparison of FIGS. 8 and 11 shows, the radial slot 6 extends over more than half the circumference of the projection 20 and thus over a substantial part of the circumference of the spinning rotor 1.

The height h (see FIG. 10) of the outlet opening 61 of the radial slot 6 (measured parallel to the rotor axis 15) is smaller than the height H of the fiber feed channel 3 (measured perpendicular to the channel axis) in the region of its outlet opening 302.

A sliver 9 to be spun is presented in the usual way to the feed device 7, which feeds the sliver 9 to the opening roller 74. The opening roller 74 combs individual fibers 90 out of the leading end of the sliver 9, which fibers enter the fiber feed channel 3 and from there into the radial slot 6. The dimensioning of the radial slot 6, which is narrow in height h and, on the other hand, due to the spreading of the radial slot 6 over a wide area of the rotor circumference, means that the fibers 90 emerging from the fiber feed channel 3 and fed to the radial slot 6 are initially in the direction of the rotor axis 15, 6, 8, 10 and 15 in a plane parallel to the plane laid by the fiber collecting groove 11 of the spinning rotor 1 and on the other hand in Rotation direction U of the spinning rotor 1 (see Figure 11) can be spread. The fibers 90, which emerge from the outlet opening 61 of the radial slot 60, form a thin veil and are deposited over a substantial part of the circumference of the spinning rotor 1 on a defined contour line 16 on the fiber guide surface 10 of the spinning rotor 1. Due to the high rotational speed of the spinning rotor 1, a high centrifugal force acts on the fibers 90 deposited on the fiber guide surface 10, so that the fibers 90 slide on the fiber guide surface 10 into the fiber collecting groove 11, where they form a fiber ring 91 in a known manner. The end of a thread 92 is connected to the fiber ring 91 and is continuously pulled out of the spinning rotor 1 by the pull-off device 8 and continuously integrates the fiber ring 91. The thread 92 drawn out of the spinning rotor 1 by the take-off device 8 is wound onto a spool in the usual and not shown manner.

A good spreading of the fiber stream is achieved not only by the geometry of the radial slot 6, but in particular by the way in which the fiber feed channel 3 opens into the radial slot 6. It is essential that the entire fiber stream emerging from the fiber feed channel 30 is directed towards the fiber feed channel 3 opposite Fiber spreading surface 60 strikes so that the entire fiber stream is compressed and spread out by the impact of the fiber stream on the fiber spreading surface 60 of the radial slot 6. The fiber spreading surface 60 is therefore arranged in such a way that the projection of the last longitudinal section 30 of the fiber feed channel 3 in the direction of its longitudinal axis (center line 301 - see FIG. 1) falls completely into the fiber spreading surface 60. Otherwise, part of the fiber flow would not be diverted and spread, which obviously leads to turbulence and a tangled fiber deposit leads. One explanation for the surprisingly achieved improvements in yarn values could be that the measure described above achieves a very precise fiber guidance in which the individual fibers 90 interfere less less, as is apparently the case with a thick fiber stream, which has a high height H. If the deflection and spreading of the fiber stream is insufficient, fiber crossings occur, with the orientation of the fibers 90 which have already been spread out being disturbed.

The fibers 90 are conveyed on their way from the opening roller 74 into the spinning rotor 1 in an air flow which is generated by the vacuum source connected to the line 14. This transport air leaves the spinning rotor 1 over the open edge 12 of the spinning rotor 1, while the fibers 90 are deposited on the contour line 16 of the spinning rotor 1. As FIG. 10 shows, the air must be deflected strongly in order to be discharged over the edge 12 of the spinning rotor 1.

Since the fiber stream in the radial slot 6 has been strongly compressed due to the low height h of the outlet mouth 61 and, moreover, has been spread together with the transport air in the direction of rotation U of the spinning rotor 1, the speed of the air has been greatly reduced. As a result, the air loses a disruptive influence on the fibers 90 located in the fiber veil.

As a comparison of FIGS. 9 and 10 shows, the air in a configuration according to FIG. 9 must be deflected more than in an configuration according to FIG. 10, so that the risk that the air entrains fibers 90 is extremely low. However, the strip on which the fibers 90 = fiber guide surface 10 of the spinning rotor 1 reach is narrower, if the fibers 90 are fed parallel to the plane through the fiber collecting groove 11 onto the fiber guide surface 10 of the spinning rotor 1 according to FIG. In the embodiment according to FIG. 10, the fibers 90 are guided in the vicinity of the fiber guide surface 10, while in the embodiment according to FIG. 9 they obviously have to travel a longer unguided path to the fiber guide surface 10.

Surprisingly, an optimization of the yarn values is achieved if the fiber veil is fed as close as possible to the open edge 12 of the spinning rotor 1 of the fiber guide surface 10. Since the air flow sucked over the open edge 10 of the spinning rotor 1 obviously does not interfere with the fibers 90 fed to the fiber guiding surface 10 of the spinning rotor 1, there is hardly any fiber loss. It is possible to arrange the outlet opening 61 of the radial slot 6 at a very small distance e from the open edge 12 of the spinning rotor 1. This distance e is measured between the guide surface 62 of the slot 6, which faces away from the plane through the fiber collecting groove 11, and the open edge 12 of the spinning rotor 1. The distance e depends in particular on the height h of the radial slot 6. The smaller this height h of the radial slot 6, the better the compression of the fiber stream and the guidance of the fibers 90 onto the fiber guide surface 10 of the spinning rotor 1, so that this distance e can be kept smaller due to the smaller scatter of the fiber veil. As a rule, a distance e is sufficient between the guide surface 62 of the radial slot 6, which faces away from the plane through the fiber collecting groove 11, and the open edge 12, which is at least one third of the height h of the radial slot 6.

As already mentioned, the height h of the radial slot 6 very low. However, it must be ensured that the required fiber throughput is guaranteed, which in turn depends on the yarn number. The stronger the thread 92 to be produced, ie the coarser the yarn number, the more fibers 90 must also be fed into the spinning rotor 1 and the greater the height h of the radial slot 6 must be. If, on the other hand, a finer yarn is to be spun, fewer fibers 90 are to be fed in and the height h can be chosen to be correspondingly lower.

The fibers 90 leaving the outlet mouth 302 of the fiber feed channel 3 are directed against the fiber spreading surface 60 and slide along it. During their transition to the fiber guide surface 10 of the spinning rotor 1, a component of motion in the direction of the fiber collecting groove 11 is imposed on them due to the centrifugal force. Due to this component of motion and the fact that the fibers 90 have been directed against the fiber spreading surface 60, a retention force is exerted on the fibers 90 by the fiber spreading surface 60, while at the same time the rotating fiber guide surface 10 exerts a tensile force on the fibers 90. In this way, a stretching force acts on the fibers 90, which significantly favors the parallel placement of the fibers 90 in the fiber collecting groove 11.

In order to achieve a particularly effective slowdown of the air flow leaving the fiber feed channel 3, it is necessary that the air can expand to a cross-sectional area which is larger than the cross section of the fiber feed channel 3 at its outlet mouth 302. For this reason it is provided that the Cross section of the radial slot 6 in the region of its outlet opening 61 is larger than the cross section of the fiber feed channel 3 in the region of its outlet opening 302 and, if possible, a multiple of its cross-sectional area is. However, it does not have to be an integer multiple.

This large cross section at the outlet opening 61 of the radial slot 6 is achieved by appropriate dimensioning of the radial slot 6 in the direction of rotation U of the spinning rotor 1, since its height h should be as small as possible. As a comparison of FIGS. 11 and 12 shows, the radial slot 6 can have different sizes and extend over different angles. While the radial slot 6 extends only over 180 ° according to FIG. 12, this angle is significantly more according to FIG. May even extend over the entire circumference (360 °). If the angle over which the radial slot 6 extends is chosen larger, the height h of the radial slot 6 can be kept smaller.

It has been shown that it is advantageous if the radial slot 6 is less than 360 °. The radial slot 6 is formed by a slot boundary 600 with side walls 601 and 602 delimiting the radial slot 6 in front of and behind the outlet mouth 302 of the fiber feed channel 3, which extend essentially parallel to the rotor axis 15 and extend radially to near the fiber guide surface 10 of the spinning rotor 1. This slot limitation 600 can be arranged with respect to the outlet opening 302 of the fiber feed channel 3 at different points in the extension 20 of the rotor housing cover 2, for. B. only in the area behind the outlet opening 302 of the fiber feed channel 3, based on the direction of rotation U of the spinning rotor 1.

11 to 13, the slot boundary 600 extends to different degrees in the direction of the outlet opening 302 of the fiber feed channel 3. According to FIGS. 11 and 12, the side wall 601 is located to the direction of rotation U of the spinning rotor 1 - immediately behind the outlet mouth 302 of the fiber feed channel 3, while according to FIG. 14 it is next to and according to FIG. 13 essentially opposite the outlet mouth 302 of the fiber feed channel 3. Depending on the rotor diameter, negative pressure conditions, etc., the one or the other time a different design is particularly advantageous, but it has proven to be advantageous if at least a part of the slot boundary 600 extends over the area that is diametrically opposite to the Exit mouth 302 of the fiber feed channel 3 is located.

The slot limitation 600 extending in the vicinity of the fiber guide surface 10 of the spinning rotor 1 has the effect that the air emerging from the fiber feed channel 3 and transporting the fibers 90 is inevitably gradually forced radially outwards into the vicinity of the fiber guide surface 10 (sliding wall) of the spinning rotor 1 and thus the Fibers 90 are fed to the fiber guide surface 10. The fibers 90 guided to the fiber guide surface 10 are deposited thereon and thus prevented from circulating several times in the spinning rotor 1.

The slot boundary 600 can have different shapes, as a comparison of FIGS. 11 to 14 shows. According to FIGS. 11 and 12, the side walls 601 and 602 are essentially straight, which allows simple manufacture by milling. These straight side walls 601 and 602 are connected to one another by a convex surface 603. This convex surface 603 can also be formed by the thread take-off tube receiving the thread take-off channel 4.

The slot limitation shown in FIG. 14 is even more advantageous than the configuration of the slot limitation 600 shown in FIGS. 11 and 12. This is part of the ledge or Approach 20, which consists of two parts 21 and 22 (see Fig. 10). Part 21 is an integral part of the rotor housing cover 2, while part 22 is a replaceable element that is detachably connected to it. The dividing line 23 between the parts 21 and 22 is located in the plane of the guide surface 62 of the radial slot 6 facing the rotor housing cover 2, so that the replaceable element (part 22) bears against the rotor housing cover 2 at its end facing away from the spinning rotor 1. The fibers 90 emerging from the fiber feed channel 3 are in this way directed against the guide surface of the radial slot 6 forming a fiber spreading surface 60. There is no danger that the fibers 90 will reach the area of the dividing line 23 and could get caught there.

The radial slot 6 is not, as in the embodiment shown with the help of FIG. 15, delimited on both sides by one and the same component, but borders on one side with a replaceable element (part 22) carrying part (rotor housing cover 2) and becomes axially in opposite direction and also laterally limited by this interchangeable element (part 22).

The exchangeable element (part 22 of the projection 20 of the rotor housing cover 2) is pushed onto a thread take-off nozzle 40 which is screwed into part 21 of the projection 20. The thread take-off nozzle 40 merges into the thread take-off tube receiving the thread take-off channel 4 and can be regarded functionally as part of this.

10 and 14, the convex surface 603 is not formed by the thread draw-off tube forming or receiving the thread take-off channel - or the thread take-off nozzle 40 - but by the same component that also the side walls 601 and 602 forms. In this way, no slots are formed parallel to the rotor axis 15, into which fibers 90 could penetrate.

In order to avoid turbulence of the air leaving the fiber feed channel 3 and flowing through the radial slot 6, it is provided according to FIG. 14 that the side walls 601 and 602 have rounded corners 604 and 605, i.e. arcuate, into a substantially concentric to the rotor axis 15 connecting wall 606 which is no longer part of the slot boundary 600.

As FIG. 13 shows, the radial slot 6 can also be delimited by convex side walls 601 and 602. The convexity in the side wall 601 increases in the direction of the surface 603, which according to FIG. 13 is located near the outlet mouth 302 of the fiber feed channel 3, and then decreases again in the side wall 602. Such a design of the slot boundary 600, which can be dimensioned differently in the circumferential direction of the extension 20, is particularly favorable in terms of flow.

Even if in individual cases, especially with small thread numbers for which the fiber flow is weaker than for coarse thread numbers, a slit stretch of less than 180 ° can be sufficient, it has nevertheless proven to be expedient to enable thinner and broader fiber veils to be achieved choose larger angles than 180 °. The radial slot 6 should therefore, as shown in FIG. 12, generally extend over at least half the rotor circumference.

FIG. 13 shows another design of the radial slot 6, which extends over more than half the rotor circumference. The radial slot 6 extends in the circumferential direction U of the spinning rotor 1 essentially as far as in the embodiment shown in FIG. In contrast to the embodiment discussed earlier, the radial slot 6 begins, however, before the outlet opening 302 of the fiber feed channel 3 into the radial slot 6. This begins with a section 63 which is open radially to the outside. This is followed by a further section 64, which extends to the level of the outlet opening 302 of the fiber feed channel 3 and which is shielded radially outwards by a wall 65, so that the section 64 is designed in a channel-like manner. This section 64 is followed by a section 66 which is open radially outward. Section 64 bundles the air flow generated in the spinning rotor 1 and thus increases its influence on the fiber flow leaving the fiber feed channel 3. This measure also promotes the spreading of the fiber stream over the circumference of the radial slot 6.

As FIG. 8 shows, it is not absolutely necessary for the guide surface formed by the fiber spreading surface 60 and the guide surface 62 to run parallel to one another. According to FIG. 8, the fiber spreading surface 60 runs parallel to the plane through the fiber collecting groove 11, while the guide surface 62 is conical in such a way that the radial slot 6 tapers radially outward. It is also possible to design the fiber spreading surface 60 and the guide surface 62 with different conicity, the radial slot 6 again tapering outwards, or with the same conicity, as shown in FIG. 9. The two surfaces intersecting the rotor axis 15 (fiber spreading surface 60 and guide surface 62) can both not only run parallel to one another, but also parallel to the plane laid by the fiber collecting groove 11, as described above in connection with a comparison between FIGS. 9 and 10 has been explained.

The bundled air flow can also be formed or strengthened by a weak compressed air flow.

A further exemplary embodiment, in which a bundled air flow is conducted into the radial slot 6, is shown in FIG. 20. Here, the slot delimiter 600 merges into the wall 65. A section 630 opens into the section 63, through which air passes into section 63 and from there into section 64 with the outlet opening 302 of the fiber feed channel 3. Depending on the circumstances, this air can be suction air which is sucked in due to the negative pressure prevailing in the spinning rotor 1, or else excess pressure which is blown into the radial slot 6.

With the aid of an embodiment according to FIG. 20, a relatively strong air flow can be achieved in the area of the outlet opening 302 of the fiber feed channel 3, which has a positive effect on the yarn produced. This air flow, which is forced to pass through the mouth area of the fiber feed channel 3, is much more concentrated (bundled) than an air flow, which passes through the mouth area with the aid of a device according to FIG. 13, since the air flow to pass through the mouth area of the fiber feed channel 3 , does not need to flow against the centrifugal force.

The fiber distribution surface 300 of the fiber feed channel 3 and also the fiber spreading surface 60, which delimits the radial slot 6, are subject to increased wear, since the fibers 90 collide with these surfaces and have to be deflected by them. In order to increase the service life of these surfaces, it is therefore advantageous if at least one of them, but preferably both, is provided with suitable wear protection.

The wear protection can be provided, for example, as a coating, as is customary for the fiber guide surface 10 of the spinning rotor 1 or the thread take-off nozzle 40. E.g. Chrome or diamond coatings in question. It is also possible to nickel-plate the surface or, if the part comprising the fiber distribution surface 300 or the fiber spreading surface 60 consists of aluminum, to be anodized. However, other types of wear protection can also prove to be advantageous.

The type chosen depends not only on its effects with regard to wear protection, but also on its properties with respect to the fibers 90 to be spun. The geometry of the part to be protected also plays a role. For example, the inside of the last length section 30 of the fiber feed channel 3 with the fiber distribution surface 300 is very difficult to access. The choice of wear protection therefore also depends on whether the fiber distribution surface 300 is formed in one piece with the remaining circumferential area of the length section 30 or whether it is part of an insert plate 5 (see FIG. 7) or an insert designed in another way.

The invention can be advantageously retrofitted to existing rotor spinning units in a simple manner or can also be adapted to the respective rotor diameter. 15 shows an embodiment in which the radial slot 6 is part of an exchangeable element 24. 15, the element 24 is a ring which is placed on the projection 20 of the rotor housing cover 2. The radial slot 6 already begins in the projection 20, which also contains the outlet mouth 302 of the fiber feed channel 3. Different ring sizes can be attached to adapt to the rotor diameter.

Instead of the ring, the entire projection 20 or a part thereof (see FIG. 10) can also be designed to be exchangeable. Appropriately, the extension 20 is attached to the rotor housing cover 2 via a part of the thread take-off tube with the thread take-off channel 4.

15 shows, a radial slot 6 of the described embodiments can be used not only when the spinning vacuum is generated by means of an external vacuum source (see line 14), but also when the spinning rotor 1 has ventilation openings 17 by itself to generate the required spinning vacuum. In this case, line 14 is connected to the atmosphere.

16 and 17 show a further embodiment of a rotor housing cover 2 with a radial slot 6, which is essentially designed according to FIG. 14. The side walls 601 and 602 and the surface 603 connecting these walls are formed in this exemplary embodiment by an exchange part 67. This exchange part 67 has a head part 670 with the fiber spreading surface 60, which has a wear-protected surface. The exchange part 67 has a central recess 671, which widens in the head part 670 on its side facing away from the rotor housing cover 2. The recess 671 serves to receive the thread take-off nozzle 40.

The side walls 601 and 602 and the surface 603 are elongated in the axial direction and enclose a web 674 between them on their side facing away from the radial slot 6. This web 674 connects the part having the fiber spreading surface 60 of the radial slot 6 to a fastening part 672 which extends radially outwards. The web 674 with the fastening part 672 protrudes into the rotor housing cover 2 into, which has a corresponding, radially outwardly extending recess 200. In this way, the fastening part 672, which extends radially outwards with respect to the fiber spreading surface 60, is located in relation to the circumferential direction U of the spinning rotor 1 before the opening of the fiber feed channel 3.

The fastening part 672 connected to the rotor housing cover 2 is recessed in its area, which projects radially beyond the diameter of the head part 670, in the rotor housing cover 2 and is set back so far relative to the head part 670 that its surface 673 facing the spinning rotor 1 is essentially flush with the one surface 607 of the rotor housing cover 2 facing the spinning rotor. In order to rule out that fibers 90 can get caught on the edges of the recess 200 and the side wall delimiting the fastening part 672, the radial walls 677, 678 of the fastening part 672 and the walls of the recess 200 adjacent to these radial walls 677, 678 have on their the spinning rotor 1 facing side with rounded edges.

The exchange part 67 is connected to the rotor housing cover 2 by means of its fastening part 672. For this purpose, the fastening part 672 has a bore 675, through which a screw 676 extends, which is screwed into a threaded bore 201 of the rotor housing cover 2. The exchange part 67 is fixed in its exact position by the side walls of the recess 200 which cooperate with its side walls 601 and 602.

As shown in FIG. 16, the radial walls 677 and 678 of the fastening part 672 are arranged essentially in the extension of the side walls 602 and 603 delimiting the radial slot. This enables simple manufacture. Only that Side wall 602 and radial wall 678 are not exactly aligned with one another because of the fiber feed channel 3 provided here. However, these surfaces can also be arranged in alignment with one another by arranging these walls 602 and 678 at a somewhat greater distance from the fiber feed channel 3.

In the embodiments shown in FIGS. 6, 8 and 9, the radial slot 6 is arranged in the projection 20 of the rotor housing cover 2. 15, according to which the radial slot 6 is arranged in an exchangeable element 24, is more advantageous. However, the radial slot 6 according to FIGS. 10 and 16/17 is simpler to manufacture, in particular also with regard to a possible wear protection, according to which the radial slot 6 is only formed by the fiber spreading surface 60 of an exchangeable part 22 (FIG. 12 ) or an exchange part 67 is limited.

As mentioned above, it is advantageous if the height h of the radial slot 6 can be adapted to the thread size (thread number). The easiest way to do this is to make this height h adjustable, since an exchange of the part receiving or delimiting the radial slot 6 (for example part 22 in FIG. 10 or element 24 in FIG. 15) can then be dispensed with. 18 and 19 show an embodiment with which such a height adjustment of the radial slot 6 can take place. According to FIG. 18, an exchangeable part 68 is interchangeably fastened to the rotor housing cover 2 and has an essentially round outer contour in the area of its head piece 681. In the area of the radial slot 6, the exchange part 68 in turn has side walls 601 and 602 which are oriented in the desired manner - for example according to one of FIGS. 11 to 14. As with the exemplary embodiment explained previously with the aid of FIGS. 16 and 17 Here, too, the side walls 601 and 602 are extended in the direction of the rotor housing cover 2, so that the replacement part 68 projects into a corresponding recess 202 in the rotor housing cover 2. A part of the thread take-off channel 4 is provided centrally in the exchange part 68 and is continued in the rotor housing cover 2 or in a thread take-off tube used there (see FIG. 17). On the end face of the exchange part 68 facing away from the rotor housing cover 2 there is a concentric recess 681 for receiving a thread take-off nozzle 40.

On the end face of the exchange part 68 facing the rotor housing cover 2, a threaded bore 682 is provided eccentrically, into which a screw 683 extending through the rotor housing cover 2 projects. By turning this screw 683, the axial position of the exchange part 68 can be adjusted continuously.

As can be seen from FIG. 18, in order to fix the respective slot width, a spacer 69 of the desired thickness formed as a disk can be provided between the rotor housing cover 2 (or another part carrying the exchange part 68) and (fastening part of the exchange part 68). However, the position of the thread draw-off nozzle 40 also changes with respect to the rotor housing cover 2 and thereby also with respect to the spinning rotor 1, which in turn is arranged at a predetermined distance from the rotor housing cover 2.

As a rule, however, such a change in the distance between the thread draw-off nozzle 40 and the spinning rotor 1 is not desired. In order to secure the unchanged version of the thread take-off nozzle 40 with respect to the spinning rotor 1, it is provided according to FIG. 19 that a spacer 690 is inserted into the recess 681 between the exchange part 68 and thread take-off nozzle 40 at a low height h of the radial slot 6, so that this spacer 690 compensated for the change in height h. For the sake of simplicity, it can be provided that the spacers 69 and 690 are one and the same disc, which is used either between the rotor housing cover 2 (or another part carrying the exchange part 68) and the exchange part 68 or between the exchange part 68 and the thread take-off nozzle 40 depending on the desired slot width.

Depending on the size and number of gradations for the height h of the radial slot 6, a plurality of spacers 69, 690 can be used in combination or of different thicknesses, which are to be distributed over the two positions mentioned according to the desired height h and the desired position.

Regardless of whether the exchange part 67 (Fig. 16, 17) or 68 (Fig. 18, 19) is set with or without the aid of spacers 69, 690, it is always provided for the axial guidance of the exchange part 67 or 68 that this at least has a guide wall which, for example, with a corresponding counter wall of a part carrying the replacement part 67 or 68 of the rotor housing cover 2, works together. 16 to 18, these guide walls or walls are always arranged in the axial extension of the side walls 601 and 602 of the replacement part 67 and 68 and therefore - with the exception of the radial walls 677 and 678 - are not specifically identified in the figures . The counter wall or walls are formed by the side walls of the recess 200 or 202.

By choosing the location of the separation points between the exchange part 67, 68 or part 22 and the rotor housing cover 2 or another part to which the exchange part 67, 68 or part 22 is attached, fibers can usually get caught Avoid 90 at this point.

In order not to offer so-called outliers under the fibers 90, however, it can be provided as an additional measure that replacement parts 67, 68, or the part 22 and its carrier, e.g. Rotor housing cover 2, are pressed firmly against each other with their contact surfaces.

For this purpose e.g. in the replacement part 67 or 68 for the reception of the connecting element (screw 676 in Fig. 19/17 or 686 in Fig. 18/19) a bore can be provided which allows lateral displacements with respect to the connecting element. The exchange part 67 or 68 has a ramp-like surface on its side facing away from the said guide walls between the exchange part 67 or 68 and its carrier, which cooperates with a ramp-like surface (not shown) of the carrier. These ramps are inclined so that the replacement part 67 or 68 with stronger tightening of the connecting element (screw 676 or 683) with its ramp is pressed more firmly against the ramp of the carrier, which due to this pressure results in a force towards the interacting surfaces generated by exchange part 67 or 68 and carrier.

According to an alternative embodiment, for example according to the exemplary embodiments according to FIGS. 16 to 19, the desired effect can be achieved by replacing the replacement part 67 or 68 on its support by means of a connecting element (screw 676 in FIGS. 16/17 or 683 in Fig. 18/19) is attached so that this connecting element exerts a pressure on the exchange part 67 or 68 in the direction of the cooperating guide walls of the exchange part 67 or 68 and its carrier (for example rotor housing cover 2). This is done in the simplest manner in the embodiments according to FIGS. 16 to 19 in that with the replacement part 67 or 68 positioned in its working position, the bore 675 in the element 67 and the threaded bore 201 or a corresponding bore in the exchange part 68 and the threaded bore 682 are not exactly aligned with one another, but are offset by a suitable small amount in relation to one another in the Way that the threaded bore 201 or 682 is arranged closer to the rotor axis 15 than the associated bore in the loosely positioned replacement part 67 or 68 in its working position. It goes without saying that this offset can not be too large, otherwise proper attachment of the replacement part 67 or 68 to its carrier (eg rotor housing cover 2) is not possible. Such an embodiment has the desired effect in the same way regardless of whether the height h of the radial slot 6 can be adjusted or not.

In the exemplary embodiments described above, the side walls 601 and 602 are extended in the direction of the rotor housing cover 2, so that the walls projecting into the recess 202 of the rotor housing cover 2 merge into the cited side walls 601 and 602. However, this is not an essential requirement. In many cases, the guide walls of the exchange part 68 protruding into the recess 202 can be arranged offset to the side walls 601 and 602 and connected to them via a connecting surface (not shown) forming a step.

As already stated above, the fiber feed channel 3 does not need to extend into the spinning rotor 1, but can alternatively also be directed against the inner wall (fiber guide surface 10) of a substantially cone-shaped driven or stationary fiber guide body (not shown), which with its larger inner diameter is inside of the spinning rotor 1 ends. In this case The exchange part 67 or 68 can be arranged within this fiber guide body and carried by it, so that this exchange part 67 or 68 is not carried by the rotor housing cover 2 - or only with the interposition of a fiber guide body.

Claims (48)

1. A process for open-end spinning, in which the fibres arriving from a separating device are conveyed to a fibre-guide face of a spinning rotor by way of a fibre-feed duct, and are deposited in a fibre-collecting channel of the spinning rotor and are then spun into the end of a continuously drawn-off thread, characterized in that before leaving the fibre-feed duct the fibres are compressed on a fibre-distribution face and are spread out and then arrive at the outlet opening of the fibre-feed duct and are fed as a thin veil to the fibre-guide face.
2. A process according to Claim 1, characterized in that the fibres are spread out along a contour line which extends parallel to a plane in which the fibre-collecting channel is situated.
3. A process according to Claim 1 or 2, characterized in that before the fibres are fed as a thin veil to the fibre-guide face of the spinning rotor they are compressed and spread out one more time.
4. A process according to one or more of Claims 1 to 3, characterized in that the fibres are conveyed to the spinning rotor in the vicinity of its open edge.
5. A process according to one or more of Claims 1 to 4, characterized in that the fibres leaving the fibre-feed duct are subjected to a clustered air flow.
6. A process according to one or more of Claims 1 to 5, characterized in that the air emerging from the fibre-feed duct is forcibly guided into the vicinity of the spinning rotor.
7. An open-end spinning device with a spinning rotor (1) and a fibre-feed duct (3) which comprises at least two longitudinal portions (31, 30), the median lines (310, 301) of which are arranged at an angle to each other and of which the last longitudinal portion (30) in the conveying direction of the fibres terminates opposite a fibre-feed face (10) of the spinning rotor (1), for performing the process according to one or more of Claims 1 to 6, characterized in that the wall of the last longitudinal portion (30) arranged as a continuation of the penultimate longitudinal portion (31) of the fibre-feed duct (3) is constructed in the form of a fibre-distribution face (300) which extends substantially at a right angle to the plane (E) defined by the median lines (310, 301) of the said two longitudinal portions (31, 30), in such a way that on account of their centrifugal force the fibres can be flung against the fibre-distribution face (300) and can be spread out there, and then pass along the fibre-distribution face (300) to the outlet opening (302) of the fibre-feed duct (3), and can be deposited as a thin veil on the fibre-guide face (10).
8. A device according to Claim 7, characterized in that the fibre-distribution face (300) is formed as a planar face.
9. A device according to Claim 8, characterized in that the fibre-distribution face (300) is formed as a convex face.
10. A device according to one or more of Claims 7 to 9, characterized in that the fibre-distribution face (300) is enlarged to an increasing extent as the distance from the penultimate longitudinal portion (31) of the fibre-feed duct (3) increases.
11. A device according to one or more of Claims 7 to 10, characterized in that the length (a) of the fibre-distribution face (300) is at most as large as the average staple length of the fibres (90) arriving for spinning.
12. A device according to one or more of Claims 7 to 11, characterized in that the outlet opening (302) of the fibre-feed duct (3) tapers inwardly along the said plane (E).
13. A device according to Claim 11 or 12, characterized in that the fibre-distribution face (300) is arranged opposite the penultimate longitudinal portion (31) of the fibre-feed duct (3) in such a way that the axial projection of the penultimate longitudinal portion (31) of the fibre-feed duct (3) falls completely on the fibre-distribution face (300) of the fibre-feed duct (3).
14. A device according to one or more of Claims 7 to 13, characterized in that the fibre-guide face (10) is part of the spinning rotor (1).
15. A device according to one or more of Claims 7 to 14, characterized in that the two last longitudinal portions (31, 30) of the fibre-feed duct (3) form an angle (α) of between 10° and 30°.
16. A device according to one or more of Claims 7 to 15, characterized in that the median lines (310, 301) of all the longitudinal portions (31, 30) are situated in the same plane (E).
17. A device according to one or more of Claims 7 to 16, characterized in that the last longitudinal portion (30) of the fibre-feed duct (3) opens into a radial slot (6) which has a second fibre-distribution face, the fibre-spreading face (60), which extends towards the fibre-guide face (10) and which is opposite the first fibre-distribution face (300).
18. A device according to Claim 17, characterized in that the recess is constructed in the form of a radial slot (6), of which the height (h) - measured parallel to the rotor axis (15) - in the region of its outlet opening (61) is smaller than the height (h) of the fibre-feed duct (3) and which extends over a substantial part of the periphery of the spinning rotor (1).
19. A device according to one or more of Claims 7 to 18, characterized in that the fibre-spreading face (60) and/or the fibre-distribution face (300) is provided with protection against wear.
20. A device according to one or more of Claims 17 to 19, characterized in that the height (h) of the outlet opening (61) of the radial slot (6) is lower at low yarn numbers than in the case of coarse yarns.
21. A device according to one or more of Claims 17 to 20, characterized in that the arrangement of the outlet opening (302) of the fibre-feed duct (3) opposite the radial slot (6) is made in such a way that the projection of the last longitudinal portion (30) of the fibre-feed duct (3) falls completely in the fibre-spreading face (60) of the radial slot (6) opposite the fibre-feed duct (3).
22. A device according to one or more of Claims 17 to 21, characterized in that the fibre-spreading face (60) and the guide face (62) arranged parallel thereto and likewise bounding the radial slot (6) intersect the rotor axis (15) at a distance from each other.
23. A device according to Claim 22, characterized in that the fibre-spreading face (60) and the guide face (62) extend parallel to a plane passing through the fibre-collecting channel (11).
24. A device according to one or more of Claims 17 to 23, characterized in that the radial slot (6) opens into the spinning rotor (1) in the vicinity of the open edge (12) of the said spinning rotor (1).
25. A device according to Claim 24, characterized in that the distance (e) - as measured parallel to the rotor axis 815) [sic - recte (15)] - of the guide face (62) of the radial slot (6) from the open edge (12) of the spinning rotor (1) is at least one third of the height (h) of the outlet opening (61) of the radial slot (6).
26. A device according to one or more of Claims 17 to 25, characterized in that the radial slot (6) extends over at least half the periphery of the spinning rotor (1).
27. A device according to one or more of Claims 17 to 26, characterized in that the radial slot (6) is bounded in front of and behind the outlet opening (302) of the fibre-feed duct (3) by lateral walls (601, 602) which extend substantially parallel to the rotor axis (15) and radially as far as the vicinity of the fibre-guide face (10).
28. A device according to Claim 27, characterized in that as viewed in the circumferential direction (U) of the spinning rotor (1) the radial slot (6) begins at a distance in front of the opening of the fibre-feed duct (3) into the radial slot (6).
29. A device according to one or more of Claims 17 to 28, characterized in that the outlet cross-section of the radial slot (6) is a multiple of the cross-section of the outlet opening (302) of the fibre-feed duct (3) into the radial slot (6).
30. A device according to one or more of Claims 17 to 29, characterized in that the radial slot (6) is bounded by two substantially straight lateral walls (601, 602) which are interconnected by a convex face (603).
31. A device according to one or more of Claims 17 to 31 [sic], characterized in that the radial slot (6) is bounded by convex lateral walls (601, 602) with varying convexity.
32. A device according to Claim 31, characterized in that the convexity increases substantially as far as the outlet opening (302) of the fibre-feed duct (3), so as then to decrease again.
33. A device according to one or more of Claims 27 to 31, characterized in that the lateral walls (601, 602) of the radial slot (6) pass in a curve into a connecting wall (606) extending concentrically to the rotor axis (15).
34. A device according to one or more of Claims 27 to 33, characterized in that the slot boundary (600) forming the lateral walls (601, 602) extends over the area arranged diametrically opposite the outlet opening (302) of the fibre-feed duct (3) with respect to the rotor axis (15).
35. A device according to one or more of Claims 17 to 34, characterized in that as viewed in the circumferential direction (U) of the spinning rotor (1) an air guide (64) opens into the radial slot (6) from the rear.
36. A device according to Claim 35, characterized in that between the entry opening of the air guide (64) opposite the fibre-guide face (10) and the opening of the fibre-feed duct (3) into the radial slot (6) the said air guide (64) is separated by a wall (65) from the interior enclosed by the fibre-guide face (10).
37. A device according to one or more of Claims 17 to 36, characterized in that the radial slot (6) is arranged at least with its outlet opening (61) in an interchangeable member (22, 24).
38. A device according to one or more of Claims 17 to 36, characterized in that the radial slot (6) is bounded in the axial direction and laterally by an interchangeable member (22).
39. A device according to Claim 37 or 38, characterized in that the interchangeable member (22) rests at the end of the radial slot (6) facing the fibre-feed duct (3) on a rotor-housing cover (2) covering the spinning rotor (1) and receiving at least the last longitudinal portion (30) of the fibre-feed duct (3).
40. A device according to Claim 39, characterized in that the interchangeable member (22) is mounted on a part receiving a thread-draw-off duct (4).
41. A device according to Claims 38 and 39, characterized in that on their side remote from the radial slot (6) the lateral walls (601, 602) bounding the radial slot (6) enclose a web (674) between themselves, by which the part of the interchangeable member (67) having the fibre-spreading face (60) is connected to a fastening part (672) which extends radially outwards and which is arranged sunk in a recess (200) in the rotor-housing cover (2) and is connected to the rotor-housing cover (2).
42. A device according to Claim 41, characterized in that the fastening part (672) has radial walls (677, 678) which are arranged as a continuation of the lateral walls (602, 603) bounding the radial slot (6).
43. A device according to Claim 41 or 42, characterized in that the radial walls (677, 678) of the fastening part (672) and the walls of the recess (200) adjacent to the radial walls (677, 678) have rounded edges on their side facing the spinning rotor (12).
44. A device according to one or more of Claims 17 to 43, characterized in that the height (h) of the radial slot (6) is adjustable.
45. A device according to Claim 44, characterized in that a spacer member (69, 690) of desired thickness can be inserted between a fastening part of an interchangeable part (67, 68) bounding the radial slot (6) in the axial direction and a part (2) supporting the said interchangeable part.
46. A device according to Claim 45, characterized by at least one spacer member (69, 690) which is optionally insertable between an interchangeable part (67, 68) bounding the radial slot (6) in the axial direction and a part (2) supporting the said interchangeable part (67, 68) and the said interchangeable part (67, 68) bounding the radial slot (6) in the axial direction and a thread-draw-off nozzle (40) supported by the said interchangeable part (67, 68).
47. A device according to one or more of Claims 44 to 46, characterized in that the radial slot (6) is bounded axially by an interchangeable part (67, 68) which has at least one guide wall (601, 602) extending in the axial direction and cooperating with a counter wall and which is axially adjustable by means of an adjusting member (676, 683).
48. A device according to one or more of Claims 37 to 47, characterized in that the interchangeable part (67, 68) is connected by means of a connecting member (676, 683) to the part (2) supporting the said interchangeable part (67, 68), the connecting member (676, 683) exerting a pressure of the interchangeable part (67, 68) and the part (2) supporting it.

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