EP0233365A2 - Method and tube for fixing and dyeing yarn - Google Patents

Abstract

In a process for setting, in particular dyeing, yarn, the yarn is wound onto axially compressible and/or telescopic centres (2; 25; 43). This produces yarn rolls (3) whose axial length is in each case less than the axial length of the centres (2; 25; 43). The yarn-bearing centres (2; 25; 43) (bobbins) are then placed on top of one another to form a column. The centres (2; 25; 43) and the yarn rolls (3) are simultaneously and axially compressed. Then a setting medium, for example a dyeing liquor, is passed through the roll (3). It is also provided that the annular clearances resulting on superposing the centres (2; 25; 43) between adjacent yarn rolls and at the end faces (5, 6) of the two outermost centres (2; 25; 43) are filled essentially pressure-tight before the compressive force is applied. There is also provided a centre system which comprises discoid spacers (8; 13, 16; 20; 30; 34, 35; 54) which overlap the centres (2; 25; 43) beyond the length of the end areas left free by the particular roll (3) and have a recess (10; 21; 32; 55) adapted to the diameter of these end areas. The outer diameter of the spacers (8; 13, 16; 20; 30; 34, 35; 54) is equal to or greater than the outer diameter of the yarn rolls (3).

Description

The invention relates to a method for fixing, in particular for dyeing, yarn, in which the yarn is wound onto axially compressible and / or collapsible sleeves and forms yarn packages, the axial length of which is in each case less than the axial length of the sleeves, the wound tubes then are placed in a column-like manner, then an axially acting compression pressure is exerted on the sleeves and the yarn packages and finally a fixing medium is passed through the packages.

The invention is also directed to a sleeve system suitable for carrying out this method with axially compressible and / or collapsible sleeves. Finally, the invention relates to a sleeve suitable for carrying out the method.

Sleeves are already known (DE-PS 16 35 084), which have several coaxial rings running in parallel planes, which are connected to one another by elastically flexible bending webs. These known sleeves are compressible in the axial direction when a suitable compression pressure is applied.

Furthermore, collapsible sleeves are known in the axial direction (DE-OS 30 49 632), each of which has a series of coaxial rings. All rings are provided with arms, which are shorter than the distance between the respective rings when the sleeve is not pushed together. Together with the arms, the rings form a cylindrical outer surface. Coupling pieces are also provided which resiliently connect adjacent rings and are located radially at a distance below the cylindrical outer surface.

These known, compressible or collapsible sleeves in the axial direction are wound with yarn, so that a coil is formed, the axial length of which is shorter than the axial length of the sleeves. It is further known to arrange such sleeves (bobbins) provided with a yarn package on a dye tube or sword in a column-like manner, the end rings of axially adjacent tubes coming into contact with one another, while annular spaces remain between yarn axles adjacent in the axial direction. Corresponding free spaces also result at the lower and at the upper end of the column, since there also a sleeve end protrudes beyond the respective yarn package.

It is also known to exert an axially acting compression pressure on the sleeves and the reels in order to assemble the yarn reels into a column which is as uniform as possible and thus to standardize the passage resistance for a fixing medium, for example a dyeing liquor. The application Such a pressure leads to the fact that the sleeves, whose axial length is greater than the axial length of the yarn package, are immediately compressed or pushed together in the axial direction. By compressing or pushing the sleeves together, the free spaces remaining between the yarn packages and at the end of the yarn package column are reduced and finally closed. The sleeves are thus first shortened to the length of the yarn package. With this shortening, the elements of the outer surface of the sleeves are displaced relative to the yarn packages. This can result in undesired deformation, confusion or damage, particularly to the inner layers of yarn.

Only after the axial length of the sleeves has been shortened to the length of the yarn packages does the applied compression pressure then cause the yarn packages to compress. The end faces of adjacent yarn packages come into direct contact with one another, which can lead to deformations and confusion. Then a fixing medium, e.g. a dyeing liquor through which the compressed yarn column formed from the yarn packages passes.

After the fixing process, for example the dyeing process, has been completed, the sleeves (bobbins) provided with yarn packages are removed from the dye tube or sword. The bobbins that are then present are unsuitable for dispatch for immediate further use, since the end faces have deformations and confusion and do not guarantee a secure hold of the yarn package on the tube during dispatch. The handling of such bobbins is difficult because the ends of the sleeves do not protrude over the yarn packages and are therefore difficult to grasp. Furthermore, it is not possible to accommodate a thread reserve on these sleeves in such a way that it remains safely accessible even after the compression and the fixing process.

It is also already known (DE-OS 1 460 270) to stack perforated sleeves on which yarn to be dyed is stacked on a tube. Between the sleeves stacked in this way there is a spacer, which consists of two interconnected, ring-shaped and essentially flat plates. It extends into the space between yarn packages of adjacent sleeves. The inner diameter of the spacer corresponds approximately to the outer diameter of the tube, while the sleeve inner diameter is larger than the outer tube diameter.

Although the known device also strives for a uniform flow through the yarn package, it cannot be achieved to a sufficient extent with the complex means described there. The individual yarn packages are not compressed and therefore not homogenized in terms of their resistance to penetration. An ineffective outflow of the fixing medium must also be expected in the area of the end faces of the winding.

The object on which the invention is based is to eliminate the disadvantages of the relevant prior art and to provide a method and a sleeve system and a sleeve with which, for fixing, in particular dyeing, uniform compression of the winding without disturbing the course of the yarn can also be brought about in the inner winding layers.

This object is achieved by the method according to the invention in that the sleeves and the yarn packages are axially compressed simultaneously and essentially over the same period of time by the compression pressure. In this way, relative movements between the elements forming the outer surface of the sleeves on the one hand and the inner layers of the yarn package on the other hand are excluded, since a combination always pushing or pushing the sleeves together with a pressing of the wraps. The deformations that occur in the sleeves and in the yarn reels are the same. Relative movements of the inner layers of yarn of the winding on the elements of the jacket surfaces of the sleeves are eliminated. Faults, pinching and damage to the inner layers of yarn are therefore eliminated.

Wallpaper, an inner winding consisting of several layers, can be applied to the sleeves, which protects the inner layers of the actual winding from deformation by the sleeve and acts as a filter when it is fixed when it is flown through from the inside to the outside. The process is also suitable for yarn packages with not flat, but spherical end faces, for example. Additive, oil or the like can be added to the fixative, in particular the dye liquor. The finished bobbins can be shipped and processed without being rewound. Compression results in a more favorable crossing angle of the yarn layers for processing (unwinding, overhead take-off) of the winding.

This new process can include be carried out using sleeves of the type mentioned in the introduction. But it can also be used with sleeves which have radially projecting flanges at both ends, between which there is a yarn package.

The method according to the invention can also be carried out in such a way that the annular free spaces which result when the sleeves are placed between adjacent yarn packages and on the end faces of the two outermost sleeves are filled essentially pressure-tight before the compression pressure is applied. It follows from this that when this method is used, the sleeves used after fixing, for example dyeing, at least in the area of the sleeve protruding from the wrap. This protruding part of the sleeves can hold a thread reserve which is exposed to the fixing medium, for example the dyeing liquor, and remains freely accessible. This part can be used for always recognizable lot identification. It can also be used to touch and thus to handle the coils properly.

In addition, the method according to the invention prevents the end faces of adjacent yarn packages from coming into direct contact with one another. Swirling of the yarn in the area of the end faces is also avoided.

According to this method, the yarn packages form a continuous column with the fillings in the free spaces, so that the compression pressure acts in the same way from the start on the compressible and / or collapsible sleeves on the one hand and on the yarn package on the other. Sleeves and yarn packages are thus deformed to the same extent so that there are no relative movements between these two components of the bobbins.

The inventive method can also be carried out so that disc-shaped spacers are used in the annular spaces. These disc-shaped spacers determined the contour and position of the end faces of the roll even after fixing or dyeing. They lead to a smooth fixation of the wrap in the end face area, which improves the yarn run-off properties.

A sleeve system suitable for carrying out the method according to the invention provides that it comprises disc-shaped spacers which overlap the sleeves over the length of the end regions left free by the respective winding and a receptacle adapted to the diameter of these end regions have and that the outer diameter of the spacers is equal to or larger than the outer diameter of the yarn package. The disc-shaped spacers close the space between the yarn packages of adjacent bobbins. The receptacle of the spacers reaches over the end regions of the sleeves that are released from the windings and also keeps them free during the compression or pushing together of the sleeves, so that these regions protrude beyond the windings even after compression and that thread reserves accommodated in these regions are not covered .

The sleeve system according to the invention can also be designed so that the spacers are adapted to the contours of the facing end faces of adjacent yarn packages. The spacers are particularly simple, a slight compensation between the free end areas of the adjacent sleeves results automatically.

The sleeve system according to the invention can also be designed such that the spacers each have at least one collar which projects radially inward beyond the receptacle and which engages between axially adjacent sleeves. This collar gives the spacers a certain position in relation to the sleeve ends.

The sleeve system according to the invention can also be designed so that the inner diameter of the collar is adapted to the outer diameter of a dye tube.

The sleeve system according to the invention can also be designed such that the inner diameter of the collar is adapted to the outer diameter of a collar of a sleeve which engages in an adjacent sleeve. This design can ensure that in the end ring area of the axially adjacent sleeves, no fixing medium emerges in an undesirable manner.

The sleeve system according to the invention can also be designed such that the spacers each have two substantially parallel, mutually supported disks.

The sleeve system according to the invention can also be designed in such a way that the spacers on both sides of a radial plane have the same mirror image. This has the particular advantage that when threading the spacers onto the dye tube or sword there is no distinction between an upper and a lower side of the spacers, so the pieces can be placed indiscriminately.

The sleeve system according to the invention can also be designed such that, at least in the case of the spacers arranged at the ends of the coil column, the collar runs in the plane of an end face of the spacers. Such spacers are particularly suitable as foot or head pieces in order to fill the free spaces on the end faces of the two outermost sleeves. But it is also possible to use such spacers in the area between two sleeves.

The sleeve system according to the invention can also be designed such that the spacers are divided into at least two parts that can be joined together in the radial direction. This can be associated with advantages with regard to the manufacture and use of the spacers, since these can then also be inserted subsequently between coils.

The sleeve system according to the invention can also be designed such that each sleeve has a thread reserve groove in an end region left free from the respective winding.

To carry out the method according to the invention, the invention proposes a sleeve, which is characterized in that one of the end rings has a collar on its axially outer edge with a reduced outside diameter compared to the outer diameter of the end ring and that the other end ring has a socket at its axially outer end forms, whose inner diameter is equal to or slightly larger than the reduced outer diameter of the federal government. Such sleeves can be placed axially one inside the other and form a seal in the area of the parting line in order to prevent the undesired passage of a fixing medium.

The sleeve according to the invention can also be designed so that the end ring having the socket has a thread reserve groove. The thread reserve groove can be covered by a spacer and thus protected.

The sleeve according to the invention can also be designed such that the webs each incline to an axially parallel surface line.

The sleeve according to the invention can also be designed such that at least some webs of each web row running in the circumferential direction between the rings are provided with spacer bones. The spacer cams ensure that the individual sleeve cannot be pressed together in such a way that sufficient passage for the fixing medium is excluded. Rather, these distance cams ensure that the maximum compression of the sleeve is not exceeded and a minimum cross section remains free for the passage of the fixing medium.

Finally, the sleeve according to the invention can be designed such that the spacer cams are designed as thickened portions of the webs in the region of their longitudinal center.

In the following part of the description, some embodiments of the method according to the invention, the sleeve system and the sleeve are described with reference to drawings.

• Fig. 1 einen Teilschnitt durch mehrere übereinander angeordnete Spulen mit an einem Färberohr geführten Distanzstücken,
• Fig. 2. einen Axialschnitt durch ein zu einer Radialebene im wesentlichen spiegelbildliches Distanzstück,
• Fig. 3. eine der Fig. 1 ähnliche Darstellung einer weiteren Ausführungsform des erfindungsgemäßen Hülsensystems, bei dem die Distanzstücke auf den Mantelfl ächen der Hülsen geführt sind,
• Fig. 4. einen Axialschnitt durch ein als Fuß- oder Kopfstück geeignetes Distanzstück,
• Fig. 5. eine den Fig. 1 und 3 ähnliche Darstellung einer weiteren Ausführungsform des erfindungsgemäßen Hülsensystems, bei dem die zwischen den Garnwickeln liegenden Distanzstücke jeweils auf einem Bund einer Hülse geführt sind,
• Fig. 6 eine teilweise im Schnitt dargestellte Seitenansicht einer Hülse der Art, die in Fig. 5 schematisch dargestellt ist,
• Fig. 7 eine Teilschnitt nach der Linie 7-7 in Fig. 6 und
• Fig. 8 einen Axialschnitt betreffend das Ineinandergreifen zweier Hülsen gemäß den Fig. 6 und 7 mit Distanzstück.

It shows:

• 1 shows a partial section through a plurality of coils arranged one above the other with spacers guided on a dye tube,
• 2 shows an axial section through a spacer which is essentially mirror-image to a radial plane,
• 3 shows a representation similar to FIG. 1 of a further embodiment of the sleeve system according to the invention, in which the spacers are guided on the lateral surfaces of the sleeves,
• 4. an axial section through a spacer suitable as a foot or head piece,
• 5 shows a representation similar to FIGS. 1 and 3 of a further embodiment of the sleeve system according to the invention, in which the spacers located between the yarn packages are each guided on a collar of a sleeve,
• 6 is a side view, partially in section, of a sleeve of the type shown schematically in FIG. 5;
• Fig. 7 is a partial section along the line 7-7 in Fig. 6 and
• Fig. 8 is an axial section relating to the interlocking of two sleeves according to FIGS. 6 and 7 with a spacer.

1, 3 and 5, a dye tube 1 is shown in dash-dotted lines, on which coils are arranged axially one above the other, each of which consists of an axially compressible and / or collapsible sleeve and a yarn package seated thereon. The column thus guided by the dye tube only consists of three coils in the drawings, while in practical use the number of coils arranged axially one above the other is considerably higher.

1, the coloring tube 1 carries three sleeves 2, which are shown only schematically in this figure. The sleeves 2 are guided on the dye tube 1. Each sleeve 2 carries a yarn package 3 and forms a spool with it. In their lower end region 4, the sleeves protrude beyond the lower end face 5 of the associated yarn package 3. In a corresponding manner, the upper end region 6 projects beyond the upper end face 7. A spacer 8, which is designed as an annular body and has two side surfaces 9 running parallel to one another, is arranged between each two adjacent bobbins consisting of sleeves 2 and yarn packages 3. The spacer 8 has the same mirror image on both sides of a radial plane. It has a receptacle 10 on both sides which is adapted to the lateral surfaces 11 of the sleeves 2 and which extends over the end region 4, 6 projecting from the yarn packages 3 of these sleeves 2.

With respect to the receptacle 10, a collar 12 of the spacer 8 projects radially inwards. It has a cylindrical inner edge, the diameter of which is adapted to the outer diameter of the dye tube 1.

A spacer 13 with an upper side surface 14 sits on the lower end region 4 of the sleeve 2 arranged at the bottom, which is on the lower end surface 5 of the adjacent yarn package 3 comes to the plant. The lower spacer 13 is also designed as a disk-shaped ring body. Its central receptacle 15 is adapted to the outer diameter of the outer surface of the sleeve 2.

In a corresponding manner, an upper spacer 16 sits on the upper end region 6 of the sleeve 2 arranged at the top.

The embodiment according to FIG. 3 differs from that previously described only in that spacers 20 are arranged between the bobbins consisting of sleeves 2 and yarn packages 3, the central receptacle 21 of which is guided only on the lateral surfaces of the sleeves 2, that is to say none radially inwards protruding collar. For the rest, reference is made to the above description of FIG. 1 with regard to this embodiment. Corresponding parts are provided with the same reference symbols in both drawings.

5 provides sleeves 25 on which the yarn packages 3 are arranged. These sleeves have a collar 27 at their end region 26 shown at the bottom in FIG. 5, the outer diameter of which is equal to or slightly smaller than the inner diameter of the sleeves 25 at the upper end region 28. This means that two axially adjacent sleeves 25 can be inserted into one another, wherein the collar 27 of one sleeve 25 engages in the upper end region 28 of the adjacent sleeve and is surrounded there by a socket 29.

Between S formed from sleeves 25 and yarn packages 3 S a spacer 30 is arranged, which has two parallel side surfaces 31. It forms a central receptacle 32 which is adapted to the outer diameter of the socket 29 and overlaps it. At one axial end of this receptacle 32, a collar 33 projects radially inward, the inside diameter of which is adapted to the outside diameter of the collar 27. The Collar 33 is delimited on the one hand by a side surface 31 of the spacer 30.

A lower spacer 34 and an upper spacer 35 sit on the lowermost end region 26 of the sleeve 25 arranged at the bottom and on the upper end region 36 of the sleeve 25 arranged at the top.

In the embodiments described with reference to FIGS. 1, 3 and 5, the yarn packages in connection with the spacers form a column, the axial length of which corresponds to the total length of the sleeves which are placed one above the other. Accordingly, if a compression pressure is exerted on the sleeves and the column of the yarn packages at the same time, both are shortened in terms of their axial length in the same way.

In Fig. 2, a spacer 8 is shown, which corresponds to that shown schematically in Fig. 1. These are two mirror-image-like annular sheet metal parts that are firmly connected to one another. They are welded together in the region of the collar 12 and are supported against one another in the rest by means of fixed spacers 37.

FIG. 4 shows a spacer 38 which essentially consists of a sheet metal part of the spacer according to FIG. 2, which is welded to a flat cover plate 39 and is connected to it by means of spacers 40.

The spacer 38 can be used between two coils in the manner shown schematically in FIG. 5. Otherwise, this spacer 38 can also be attached to the ends of a coil column, in which case the inner diameter of its central opening 41 is adapted to the outer diameter of a dye tube 1, while the inner diameter of the receptacle 42 is adapted to the outer diameter of the outer surface of the sleeves.

1, 3 and 5 are sleeves which are axially compressible and / or compressible, that is to say they can be shortened in their axial length by the action of pressure. Such a sleeve is described in cooperation with a spacer with reference to FIGS. 6 to 8.

The sleeve 43 shown in FIGS. 6 to 8 has a lower end ring 44 which has a thread catching groove 45 and is provided with a thread reserve groove 46. The lower end ring 44 forms a socket 47 at its radially outer end.

A jacket 48 adjoins the end ring 44 and has intermediate rings 49 which lie in parallel planes which are normal to the sleeve axis 50. Each intermediate ring 49 is coupled to the adjacent intermediate rings or to an end ring via deformable webs 51, each of which is inclined to an axially parallel surface line. 6, in the rows of webs shown, each web 51 is provided with a spacing cam 51a, which presents itself as a thickening of the web concerned on both sides in the longitudinal center thereof. With maximum axial compression, the spacing cams 51a come to rest on the adjacent rings. All webs 51 can be provided with spacer cams 51a or only a few webs 51 evenly distributed over the circumference of the sleeve with spacer cams 51a.

At the upper end according to FIG. 6, the jacket 48 is followed by an upper end ring 52, the most axially projecting part of which is a collar 53, the diameter of which is smaller than the diameter of the intermediate rings 49 which, together with the webs 51, define the winding surface.

The outer diameter of the collar 53 corresponds essentially to the inner diameter of the socket 47 of the lower end ring 44. This means that sleeves of this type can be axially inserted into one another, the collar 53 of the end ring 52 sealingly engaging in the socket 47 of the end ring 44.

The sleeve 43 according to FIGS. 6 to 8 can be compressed by an axially acting compression pressure. The webs 51 deform, so that the distance between adjacent intermediate rings 49 or an intermediate ring 49 and one of the end rings 44 or 52 is shortened.

Fig. 8 makes it clear that on a collar 53 of the sleeve 43 arranged there below a spacer 54 is first placed, which is disc-shaped. This spacer 54 has a cylindrical receptacle 55, from which radially outward two parallel walls 56, 57 extend, which are supported on one another by ribs 58. These walls 56, 57 come to rest with their outer side surfaces on yarn packages, not shown. In the plane of the wall 56 there is a collar 59 which projects radially inwards and whose inside diameter is adapted to the outside diameter of the collar 53.

The end ring 52 forms a shoulder 60 on which the collar 59 is supported. The end of the end ring 44 of the axially adjacent sleeve 43 is supported on the other side of the collar 59. The thread reserve groove 46 is overlapped by the receptacle 55, so that a thread reserve located in this groove 46 cannot be covered even with axial compression of the yarn package and always remains free.

Thermoplastic materials, which can be colored in the desired manner for identification purposes, are particularly suitable for the production of the coloring sleeves and the separator.

All described sleeve systems have in common that their coils can be placed on a dye tube in a guided manner. First, a spacer is attached to the dye tube as a foot piece. Then the first coil is attached. The annular space above the lower end area protruding from the yarn package is filled by the spacer. Then spacers and coils are alternately applied, the spacers filling the spaces between adjacent windings. Finally, a spacer is placed on the head.

Now a compression pressure is applied, which acts simultaneously on the sleeves and on the column formed from yarn packages and spacers.

Finally, a fixing medium, which can be a dyeing liquor, is pressed through the compressed yarn packages. The bobbins can be dried and are ready for further processing of the yarn.

Claims (18)

1. A method for fixing, in particular for dyeing, yarn, in which the yarn is wound onto axially compressible and / or collapsible sleeves and forms yarn packages, the axial length of which is in each case less than the axial length of the sleeves, the spooled sleeves are then guided in a columnar manner are superimposed, then an axially acting compression pressure is exerted on the sleeves and the yarn packages and finally a fixing medium is passed through the packages, characterized in that the tubes and the yarn packages are axially compressed by the compression pressure simultaneously and essentially over the same period of time. 2. The method according to claim 1, characterized in that when the sleeves are placed one on top of the other between adjacent yarn packages and on the end faces of the two outermost sleeves, the annular free spaces which result from the application of the compression pressure are filled essentially pressure-tight. 3. The method according to claim 1 or 2, characterized in that disk-shaped spacers are used in the annular spaces. 4. Suitable for carrying out the method according to one of the preceding claims sleeve system with axially compressible and / or collapsible sleeves, characterized in that it washers shaped spacers (8; 13,16; 20; 30; 34,35; 38; 54) which overlap the sleeves (2; 25; 43) over the length of the end regions left free by the respective winding (3) and one Diameter of these end regions adapted receptacle (10; 21; 32; 55) and that the outer diameter of the spacers (8; 13,16; 20; 30; 34,35; 38; 54) is equal to or larger than the outer diameter of the yarn package ( 3). 5. sleeve system according to claim 4, characterized in that the spacers (8; 13,16; 20; 30; 34,35; 54) are adapted to the contours of the facing end faces (5,6) of adjacent yarn packages (3). 6. sleeve system according to claim 4 or 5, characterized in that the spacers (8; 54) each have at least one on the receptacle (10; 32; 55) radially inwardly projecting collar (12; 33; 59), the between axially adjacent sleeves (2; 25; 43) engages. 7. sleeve system according to one of claims 4 to 6, characterized in that the inner diameter of the collar (12; 33; 59) is adapted to the outer diameter of a dye tube (1). 8. Sleeve system according to one of claims 4 to 6, characterized in that the inner diameter of the collar (12; 33; 59) the outer diameter of an in an adjacent sleeve (25; 43) engaging collar (27) of a sleeve (25; 43) is adjusted. 9. sleeve system according to one of claims 4 to 8, characterized in that the spacers (8; 13,16; 20; 30; 34,35; 54) each have two substantially parallel, mutually supported discs. 10. Sleeve system according to one of claims 4 to 9, characterized in that the spacers (8; 20) are of identical design on both sides of a radial plane in mirror image. 11. Sleeve system according to one of claims 5 to 9, characterized in that at least at the ends of the coil column arranged spacers (38) of the collar (12) in the plane of an end face of the spacers (38). 12. Sleeve system according to one of claims 4 to 11, characterized in that the spacers are divided into at least two parts which can be joined together in the radial direction. 13. Sleeve system according to one of claims 4 to 12, characterized in that each sleeve (2) has a thread reserve groove (46) in an end region left free from the respective winding (3). 14. To carry out the method according to any one of claims 1 to 3 suitable cylindrical or slightly conical, compressible in the axial direction sleeve which has intermediate rings arranged between end rings, wherein elastically deformable webs are arranged between two adjacent rings, characterized in that one the end rings (52) on its axially outer edge has a collar (53) with an outer diameter that is reduced compared to the outer diameter of the end ring (52) and that the other end ring (44) forms a socket (47) at its axially outer end, the inner diameter of which is equal to or slightly larger than the reduced outside diameter of the collar (53). 15. Sleeve according to claim 14, characterized in that the socket (47) having the end ring (44) has a thread reserve groove (46). 16. Sleeve according to claim 14 or 15, characterized in that the webs (51) each incline to an axially parallel surface line. 17. Sleeve according to one of claims 14 to 16, characterized in that at least some webs (51) of each row of webs running in the circumferential direction between the rings (44, 52, 49) are provided with spacer cams (51a). 18. Sleeve according to claim 17, characterized in that the spacer cams (51a) are formed as thickened portions of the webs (51) in the region of their longitudinal center.

Images