WO2008080707A1

WO2008080707A1 - Joint arrangement with axial mounting

Info

Publication number: WO2008080707A1
Application number: PCT/EP2007/062817
Authority: WO
Inventors: Thomas Weckerling; Nader Khoshoei; Ida Hassenrik
Original assignee: Gkn Driveline International Gmbh
Priority date: 2006-12-29
Filing date: 2007-11-26
Publication date: 2008-07-10

Abstract

Joint arrangement (1) having a joint outer part (2), a joint inner part (8) which has a dimension (11), ball (13) for transmitting torque from the joint inner part (3) to the joint outer part (2), and a cage (14) which can be arranged between the joint outer part (2) and joint inner part (8) and which has a plurality of cage windows (15) which each hold at least one ball (13), wherein the cage (14) has at least one mounting end side (16) with an opening width (17) which is greater than the dimension (11) of the joint inner part (8), and additionally has a cage outer sphere (18) with an outer sphere centre point (19), and a cage inner sphere (20) with an inner sphere centre point (21), wherein the outer sphere centre point (19) and the inner sphere centre point (21) are arranged offset with respect to one another.

Description

Joint arrangement with axial mounting

The invention relates to a joint arrangement having a joint outer part, a joint inner part which has a dimension, balls for transmitting torque from the joint inner part to the joint outer part and a cage which can be arranged between the joint outer part and joint inner part and which has a plurality of cage windows which each hold at least one ball. Furthermore, a method is proposed for manufacturing and mounting a joint arrangement. The invention is applied in particular in the field of motor vehicles.

Cages in constant velocity joints have the function of keeping all the balls in a common plane, which is considered as the centre plane of the cage and which forms what is referred to as an angle-bisecting plane at any desired articulation angles between the joint outer part and joint inner part. In this context, in most joint arrangements the balls are guided directly onto the angle-bisecting plane by the shape of the ball tracks in the joint outer part and joint inner part, this guidance being very effective in the plane extending between the intersecting axes of the joint outer part and joint inner part, but being nearly ineffective in a plane which is perpendicular thereto.

Since the outer shape of the cage needs to be conical, it is generally not possible to introduce the joint inner part into the cage in a coaxial orientation since the dimension of the joint inner part over the longitudinally extending webs between the inner ball tracks is greater than an opening width of the cage at its end side. This results in complicated mounting processes which impede automation of the assembly.

DE 196 48 537 Cl discloses a joint shaft with two constant velocity joints which each have a cage which permits axial mounting with the joint inner part by virtue of the fact that longitudinal grooves are provided on the inside of the cage, in each case in a central assignment with respect to the cage windows, so that the webs between the ball tracks can be introduced through these grooves and the joint inner part is subsequently rotated with respect to the cage by one half window division in such a way that the ball tracks are assigned to the cage windows and the webs between the ball tracks are assigned to the dividing webs between the cage windows. As a result, the lateral circumferential webs on the cage windows which constitute the most highly loaded regions in joints which run around in a bent shape are weakened to an extreme degree.

WO 03/046397 Al discloses another solution proposal for the configuration of a cage. In said document, mounting enlargements which run in the direction of the longitudinal axis on the inner face of the cage and which start from at least one cage edge and have an effective diameter which is larger than the smallest diameter of the two end openings are provided. In this context, the joint inner part can be introduced coaxially from at least one side of the cage which is embodied with mounting enlargements, as a result of which the mounting of the joint is made significantly easier and is amenable to automation.

In such axially mounted joint arrangements, the cage therefore has to have a mounting opening which is at least as large as the outer diameter of the inner race or the maximum dimension of the joint inner part. However, as a result of the mounting opening, the mechanically effective cross section of the part of the cage which lies on the mounting side is to a certain extent weakened to an undesirable degree. In other known joint arrangements, attempts are made to counteract this disadvantage by generally strengthening the web cross section, it being ultimately necessary to provide separate mounting enlargements. However, such mounting enlargements are complex and costly to manufacture.

Taking this prior art as a basis, the object of the present invention is to at least partially resolve the problems discussed in relation to the prior art and in particular to provide a joint arrangement which can be mounted and dismounted axially in a particularly easy way and at very low cost.

These objects are achieved with a device as per the features of Patent Claim 1 and a method as per Patent Claim 8. Further embodiments of the device are specified in patent claims which are formulated in a dependent fashion. It is to be noted that the features which are specified individually in the subclaims can be combined with one another in any desired technically appropriate way and define further embodiments of the invention.

The joint arrangement according to the present invention has at least the following features: a joint outer part which has a connection side, an opening side and a cavity which is limited by an inner face, and outer ball tracks which extend on the inner face between this connection side and opening side, - a joint inner part which is positioned in the cavity of the joint outer part and has inner ball tracks which extend on an outer face, and a dimension, wherein in each case an outer ball track and an inner ball track form a track pair with one another, one ball in each track pair, - a cage which can be arranged between the joint outer part and joint inner part, also in the cavity, and which has a plurality of cage windows which each hold at least one ball, wherein the cage has at least one mounting end side with an opening width which is greater than the dimension of the joint inner part and additionally has a cage outer sphere with an outer sphere centre point and a cage inner sphere with an inner sphere centre point, wherein the outer sphere centre point and the inner sphere centre point are arranged offset with respect to one another.

The joint arrangement is preferably what is referred to as a constant velocity joint, in particular a joint arrangement of the type of what is referred to as a Rzeppa joint or what is referred to as a counter track joint. In this respect, fully inclusive reference can be made in particular once more to the introductory statements relating to the prior art and the explanations contained therein relating to the definition of the counter track joint.

With regard to the joint outer part, it is to be noted that said joint outer part is generally configured in the form of a bell, with the side from which the cavity can be reached constituting the opening side. The side which is axially opposite is referred to as the connection side. While the cavity has a shape which corresponds essentially to that of a bell, there are generally arranged on the inner face of said cavity an even number of outer ball tracks, for example six, eight, ten or else twelve, with six or eight ball tracks being preferred. These ball tracks are introduced in the manner of depressions into the joint outer part starting from the cavity. Two different configurations of the ball tracks are provided in the counter track joints so that said ball tracks are known as first and second outer ball tracks. In counter track joints the embodiment in which first ball tracks and second ball tracks are arranged alternately in the circumferential direction of the joint outer part is preferred.

The joint inner part is generally embodied in the manner of an inner race, said part having, in the central region, an opening in which, for example, a shaft can be accommodated in order to transmit a torque. In this context it is possible for this opening also to be designed so as to implement a wedge/groove connection or the like to the shaft. In addition, the joint inner part has an outer face which is relatively complex in shape and into which ball tracks which also run essentially in an axial direction extend. The number of inner ball tracks corresponds to the number of outer ball tracks, in which case, if appropriate in the case of counter track joints, the assignment of first and second inner ball tracks is also clearly predefined. Here, a dimension is defined with respect to the joint inner part. This is meant to refer in particular to the diameter of a minimum virtual circle which encloses the joint inner part (referred to as an envelope), for example at least over the axial length of the inner ball tracks or over the part of the joint inner part which is moved when it is mounted in the interior of the cage.

If, on the counter track joints, the joint inner part is then positioned in the cavity of the joint outer part at a location as is present on an extended constant-velocity joint (articulation angle = 0°), it is possible to discern, in various sectional planes through the longitudinal axis of the joint outer part on the one hand and the ball tracks on the other, that in each case a first outer ball track and a first inner ball track form a track pair, as do in each case also a second outer ball track and a second inner ball track. In other joint arrangements, the inner and outer ball tracks can also be oriented with respect to one another in such a way that they form tracks pairs (of the same type).

In the case of counter track joints, it is now possible to consider a plane perpendicular to the longitudinal axis of the joint outer part which runs through the centre point of the joint. Tangents to the locations on the ball tracks in the centre plane of the joint form what is referred to as an angle of aperture here (preferably in a range from 16° to 18°). "Angle of aperture" is intended here in particular to express the direction in which the angle is opening. In the case of counter track joints, it is now predefined that the first track pairs form an angle of aperture towards the connection side and the second track pairs form an angle of aperture towards the opening side. In other joint arrangements, the angle of aperture of all the track pairs is oriented in the same way, in particular in the direction of the opening side.

In addition, these track pairs each form a ball which transmits torque. Basically, the term "ball" is used as a preamble for all the suitable bodies which transmit torque. The cage which is positioned between the joint outer part and the joint inner part serves, during operation of the joint, to guide the balls in the track pairs at least temporarily. The cage generally has as many cage windows as the number of balls which it accommodates, but it is also possible for a plurality of balls, in particular two, to be arranged in a cage window. The joint plane or ball plane is oriented perpendicular to the joint axis (or axis of the joint outer part) and extends through the centre point of the balls in the unbent state of the joint arrangement.

The cage is provided with a (partially) spherical cage inner face (cage inner sphere) and a (partially) spherical cage outer face (cage outer sphere). The centre point of the cage outer face and the centre point of the cage inner face are offset axially along a joint axis. In other words this means that the cage inner sphere and the cage outer sphere are not oriented concentrically with respect to one another but rather displaced with respect to the cage axis. Furthermore, the cage is embodied with a lateral mounting opening which has a larger opening width (or a larger opening diameter) than the maximum dimension of the inner part. The joint axis corresponds here to the rotational axis of the unarticulated joint arrangement. As a result of the sufficiently large mounting opening, the joint inner part can be mounted particularly easily in the axial direction.

A joint arrangement of this type is preferred in particular if the cage has just one mounting end side. This ensures advantageous use in particular in the case of what are referred to as AC joints, UF joints and counter track joints because, in this way, the end side which lies opposite the mounting end side can still carry out a control function of the joint inner part (if appropriate at an articulation angle greater than 0°).

According to another embodiment of the joint arrangement, the centre point of the outer sphere is offset in the direction of the mounting end side of the cage.

In this context, it is (also) preferred for the centre point of the inner sphere to be offset in the opposite direction to that of the mounting end side of the cage.

The centre point of the outer sphere and the centre point of the inner sphere are preferably positioned symmetrically with respect to the centre plane of the cage on the central cage axis, and in other words they therefore have the same offset but in opposite directions along the cage axis.

According to one development of the joint arrangement, the cage has a cage inner cylinder which adjoins the cage inner sphere and which also extends as far as a mounting end side. It is preferred for the cage inner cylinder to start directly at the mounting end side and to extend in the direction of the cage axis at least as far as the cage windows, if appropriate even (at least partially) over the cage windows. The cage inner cylinder can, if appropriate, be embodied with depressions, but a smooth cylindrical shape is preferred. As a result, on the inside a straight cross section of the cage, with which the joint inner part can just be inserted, is provided in the region of the mounting opening. As a result, the cage is embodied so as to be free of undercuts with respect to the joint inner part. This also ensures that the joint inner part does not collide with the cage and damage the cage inner sphere during mounting. It is also preferred for the cage windows of the cage to be arranged asymmetrically with respect to the centre plane of the cage. This means in particular that centre points which are positioned on an individual cage window plane can be assigned to the cage windows, and here said plane does not correspond to the centre plane of the cage. This applies in particular to a situation in which the joint arrangement is what is referred to as a counter track joint. Here, compared to known cage embodiments with a counter track joint, a relatively short end region (lying opposite the mounting end side) is provided, which is nevertheless sufficient owing to the smaller control function in the articulated state of the counter track joint. In this context, it is also preferred for the cage to have two different inner contours (cylindrical, spherical) in the axial direction, with the cage window extending as far as a junction between the inner contours.

It is also proposed that the joint inner part be embodied in one piece with a shaft. In other words this means in particular that it is possible to dispense with connecting means between the joint inner part (embodied for example in the manner of an inner race) and a shaft (for example towards a drive unit). Such highly loaded connecting means (for example spline toothing) can be manufactured with a long service life only with considerable expenditure on fabrication. In contrast to this, the configuration proposed here of an axially mountable joint permits a one-piece shaft joint inner part component to be used. "One piece" means in this context in particular: fabricated from one material (in particular the same material) without boundary between the components and/or designed so as to be inseparable from one another. This is particularly simple, reliable and favourable to manufacture. The inner part can, for this purpose, be embodied for example as a cast part or forged part. If appropriate, connecting techniques (which cannot be disconnected without destruction) such as a weld connection can be used to connect the ball hub and shaft.

A particularly simple and therefore cost-effective way of connecting the joint outer part to the joint inner part of the joint arrangement provides for at least some of track pairs to have a track height which is lower than the ball diameter in a limited section. Here, a projection or undercut is produced between the balls and the track pairs so that the joint inner part is held securely in the joint outer part. For an undercut it is sufficient, for example, if the ball tracks are made only a few hundredths of a millimetre narrower than the balls in a small section. During the mounting, all that is then necessary is for the joint inner part to be pressed together with the balls over this local undercut. Further securing means for connecting the outer parts and inner parts are therefore no longer necessary.

According to a further aspect of the invention, a method for manufacturing a joint arrangement is specified which comprises at least the following steps:

(a) provision of a joint outer part with a connection side, an opening side and a cavity which is bounded by an inner face, wherein outer ball tracks are formed on the inner face between this connection side and opening side;

(b) provision of a joint inner part which has inner ball tracks which extend on an outer face, and a dimension;

(c) provision of a cage with a plurality of cage windows, wherein at least one mounting end side is provided with an opening width which is greater than the dimension of the joint inner part, and the cage additionally has a cage outer sphere with an outer sphere centre point and a cage inner sphere with an inner sphere centre point, wherein the outer sphere centre point and the inner sphere centre point of the cage are arranged offset with respect to one another;

(d) positioning of the cage in the cavity of the joint outer part, wherein the cage windows are directed at the outer ball tracks;

(e) positioning of balls in the cage windows and the outer ball tracks;

(f) insertion of the joint inner part into the cage.

The method which is described here is applied in particular in the mounting of the joint arrangement described according to the invention. For this reason, in order to illustrate the method, reference can also be made (independently) to the explanations relating to the joint arrangement.

Step (f) comprises in particular a translatory insertion movement of the joint inner part along the cage axis or the joint axis or the axis of the joint outer part (axial mounting). Furthermore, step (f) can be accompanied by elastic deformation of at least one of the following components: joint inner part, joint outer part, ball, with one section of an inner and/or outer ball track being preferably of elastically deformable design (e.g. when there is a mounting force above at least 5000 Newton or even starting at 10,000 Newton).

In this method the need for working steps to be carried out for additional securing measures, which therefore involves costs, is eliminated. The mounting method is therefore simpler and quicker than has been the case hitherto with known methods.

Further advantages of the invention and the technical field are explained with respect to the following exemplary embodiments and the drawing, to which the invention is not restricted. In said drawing:

Fig. 1 shows schematically an embodiment variant of a joint arrangement according to the invention,

Fig. 2 shows schematically a cross section through a cage for a joint arrangement according to the invention,

Fig. 3 shows schematically a further embodiment variant of a joint arrangement according to the invention,

Fig. 4 shows schematically another sectional plane of the joint arrangement from Figure 3,

Fig. 5 shows schematically a further embodiment variant of a joint arrangement according to the invention, and

Fig. 6 shows schematically a detail of a further embodiment of a joint arrangement according to the invention.

Fig. 1 illustrates a joint arrangement 1 according to the invention as part of a motor vehicle 25 which is only indicated here. The joint arrangement 1 is embodied as what is referred to as a counter track joint for transmitting a torque from rotating shafts. The joint arrangement 1 has a joint outer part 2 which defines a connection side 3 and an opening side 4. Towards the opening side 4, a cavity 6 which is bounded by an inner face 5 of the joint outer part 2 is accessible. Outer ball tracks 7, which extend from the opening side 4 almost as far as the connection side 3, are introduced distributed at regular intervals over the circumference of the inner face 5.

In addition, positioned in the interior of this cavity 6 is a joint inner part 8 which has an essentially spherical outer face 9 into which what are referred to as inner ball tracks 10 are also introduced. The outer face 9 can be assigned a maximum dimension 11.

The outer ball tracks 7 of the joint outer part 2 and the inner ball tracks 10 of the joint inner part 8 form track pairs in each of which a ball 13 is provided.

In order to control or secure the balls 13 and the position of the joint inner part 8 and the joint outer part 2 to each other, a cage 14, which has a plurality of cage windows 15 which are each provided with an individual ball 13, is located between the joint outer part 2 and joint inner part 8. The cage 14 has a mounting end side 16 which is positioned near to the opening side 4 and has an opening width 17 which is larger than the dimension 11 of the joint inner part 8. In addition, the cage 14 has a cage outer sphere 18 with an outer sphere centre point 19 and a cage inner sphere 20 with an inner sphere centre point 21. The outer sphere centre point 19 and the inner sphere centre point 21 are arranged offset symmetrically with respect to the centre plane 22 of the cage. In the extended position of the joint arrangement 1 which is illustrated here, in which the axis 27 of the joint inner part and the axis 26 of the joint outer part correspond, the centre points of the spheres lie on these axes. The spherical configuration of the cage 14 with offset sphere centre points (cage offset) ensures that, despite the large angle of aperture 17 on the mounting end side 16 of the cage, a relatively thick- walled cage cross section is present so that large torques can be transmitted even in the articulated operating situation (not illustrated here) of the joint arrangement 1.

An embodiment variant of a suitable cage 14 for a joint arrangement 1 according to the invention can be seen in Figure 2. The cross section shows, on the one hand, that the cage 14 has a number of cage windows 15 which corresponds to the number of balls 13 or of track pairs 12, said cage windows 15 being oriented centrally with respect to the centre plane 22 of the cage here. On the left in Figure 2, the mounting end side 16 with the relatively large opening width 17 is also illustrated. The outer sphere 18 of the cage has an outer sphere centre point 19 here which is positioned to the left of the centre plane 22 of the cage, that is to say is positioned closer to the mounting end side 16 on the cage axis. The cage inner sphere 20 has an inner sphere centre point 21 which is positioned to the right of the cage centre plane 22 on the cage axis. The cage centre plane 22 forms a mirror axis here with respect to the positions of the outer sphere centre point 19 and the inner sphere centre point 21. In order to implement a straight, inner section for easier insertion of the joint inner part 8, the cage 14 which is illustrated here is additionally embodied with a cage inner cylinder 23 which extends as far as the cage windows 15 and starts directly from the mounting end side 16.

Fig. 3 now illustrates the mounting process for such a joint arrangement 1 in the manner of a counter track joint. The cage 14 is first positioned in the cavity 6 of the joint outer part 2 in such a way that the cage windows 15 are oriented essentially radially with respect to the outer ball tracks 7. The balls 13 are then placed in the outer ball tracks 7 through the cage windows 15. In the process, the cage 14 is oriented with its mounted end side 16 towards the opening side 4. The joint inner part 8, which is embodied here in one piece with a shaft, is now inserted axially into the cavity 6 in the direction of the axis 26 of the joint outer part until the joint inner part 8 is in the desired position or the relative position in relation to the joint outer part 2.

While Fig. 3 illustrates a section through the joint arrangement 1 in which the outer ball tracks 7 and the inner ball tracks 10 are sectioned, Fig. 4 illustrates a cross section through the intermediate regions or webs between the ball tracks which is offset with respect to the latter. It is apparent here that the inner face 5 of the joint outer part 2 corresponds essentially to the cage outer sphere 18 of the cage 14, and abuts at least partially. In the same way, the outer face 9 corresponds to the joint inner part 8 of the cage inner sphere 20 of the cage 14 and serves in particular as a guide means near to the connection side 3, at least when the arrangement of the joint arrangement 1 is articulated. The black arrow indicates that the joint inner part 8 is inserted into the mounting end side 16 with the opening width 17 which is larger than the maximum dimension 11 of the joint inner part 8.

Fig. 5 shows that a joint arrangement 1 which can be installed axially can also be embodied in the manner of a Rzeppa fixed joint. In this context, the ball tracks each form track pairs which form an angle of aperture 28 which is oriented in each case towards the opening side 4. The angle of aperture 28 is formed with the tangents in the joint centre plane with respect to the ball tracks. In the case of the counter track joints, this angle of aperture 28 with respect to adjacent track pairs points alternately to the opening side 4 and to the connection side 3. In the embodiment variant illustrated here, forces already occur with the extended arrangement of the joint arrangement 1 so that the angle of aperture has to control the movement path of the balls 13. This effect is amplified further if the axis 27 of the joint inner part is articulated with respect to the joint outer part 26, so that what is referred to as an articulation angle 29 is formed.

Fig. 6 illustrates in detail a further embodiment variant of a joint arrangement 1 in which it is to be noted firstly that here the joint inner part is embodied with a two- part shape, specifically in the manner of a hub which is provided on a shaft 24. The inner ball track 9 now has a projection 33 so that when the joint inner part 8 is inserted axially over the balls 13 a narrow point is formed. Here, the ball diameter 31 is made larger than the height 30 of the track. When the joint inner part 8 is inserted the projection 33 forms a type of undercut which has to be overcome during mounting. Such a projection 33 is, for example, provided only for some of the track pairs (for example concerning the track pairs which form an angle of aperture 28 in the direction of the opening side 4) and the joint inner part 8 can be secured in terms of its position with respect to the joint outer part 2 without providing further securing measures. List of reference numerals

Joint arrangement

Joint outer part

Connection side

Opening side

Inner face

Cavity

Outer ball track

Joint inner part

Outer face

Inner ball track

Dimension

Track pair

Ball

Cage

Cage window

Mounting end side

Opening width

Cage outer sphere

Outer sphere centre point

Cage inner sphere

Inner sphere centre point

Cage centre plane

Cage inner cylinder

Shaft

Motor vehicle

Axis of joint outer part

Axis of joint inner part

Angle of aperture

Articulation angle

Track height

Ball diameter

Offset

Projection

Claims

Patent Claims

1. Joint arrangement (1) having: - a joint outer part (2) which has a connection side (3), an opening side (4) and a cavity (6) which is bounded by an inner face (5), and outer ball tracks (7) which extend on the inner face (5) between this connection side (3) and opening side (4), a joint inner part (8) which is positioned in the cavity (6) of the joint outer part (2) and has inner ball tracks (10) which extend on an outer face (9), and a dimension (11), wherein in each case an outer ball track (7) and an inner ball track (10) form a track pair (12) with one another, one ball (13) in each track pair (12), - a cage (14) which can be arranged between the joint outer part (2) and joint inner part (8), also in the cavity (6), and which has a plurality of cage windows (15) which each hold at least one ball (13), wherein the cage (14) has at least one mounting end side (16) with an opening width (17) which is greater than the dimension (11) of the joint inner part (8) and additionally has a cage outer sphere (18) with an outer sphere centre point (19) and a cage inner sphere (20) with an inner sphere centre point (21), wherein the outer sphere centre point (19) and the inner sphere centre point (21) are arranged offset with respect to one another.

2. Joint arrangement (1) according to Patent Claim 1, wherein the cage (14) has only one mounting end side (16).

3. Joint arrangement (1) according to Patent Claim 2, wherein the outer sphere centre point (19) is offset in the direction of the mounting end side (16) ofthe cage (14).

4. Joint arrangement (1) according to Patent Claim 2 or 3, wherein the inner sphere centre point (21) is offset in the opposite direction to that of the mounting end side (16) of the cage (14).

5. Joint arrangement (1) according to one of the preceding patent claims, wherein the cage (14) has a cage inner cylinder (23) which adjoins the cage inner sphere (20) and extends as far as a mounting end side (16).

6. Joint arrangement (1) according to one of the preceding patent claims, wherein the cage windows (15) of the cage (14) are arranged asymmetrically with respect to the cage centre plane (22).

7. Joint arrangement (1) according to one of the preceding patent claims, wherein the joint inner part (8) is embodied in one piece with a shaft (24).

8. Method for manufacturing a joint arrangement (1) comprising at least the following steps: (a) provision of a joint outer part (2) with a connection side (3), an opening side (4) and a cavity (6) which is bounded by an inner face (5), wherein outer ball tracks (7) are formed on the inner face (5) between this connection side (3) and opening side (4);

(b) provision of a joint inner part (8) which has inner ball tracks (10) which extend on an outer face (9), and a dimension (11);

(c) provision of a cage (14) with a plurality of cage windows (15), wherein at least one mounting end side (16) is provided with an opening width (17) which is greater than the dimension (11) of the joint inner part (8), and the cage (14) additionally has a cage outer sphere (18) with an outer sphere centre point (19) and a cage inner sphere (20) with an inner sphere centre point (21), wherein the outer sphere centre point (19) and the inner sphere centre point (21) of the cage (14) are arranged offset with respect to one another;

(d) positioning of the cage (14) in the cavity (6) of the joint outer part (2), wherein the ball windows (15) are aligned relative to the outer ball tracks

(V);

(e) positioning of balls (13) in the cage windows (15) and the outer ball tracks

(V);

(f) insertion of the joint inner part (8) into the cage (14). Motor vehicle (25) having at least one joint arrangement (1) according to one of Patent Claims 1 to 7 or having at least one joint arrangement (1) manufactured according to a method as per Patent Claim 8.