Title of Invention

BALL JOINT WITH A SEALING BELLOW

Abstract

The invention relates to a ball and socket joint with sealing bellows (4), which sealing bellows (4) lies against the surface (17) of the ball journal (3) in the shaft region (7) if the ball journal (3) by means of a circumferentially extending terminal collar (11). The ball and socket joint proposed by the invention is distinctive due to the fact that an element (14) elastic in the journal axial direction in the form of a compression spring element is disposed in the neck region (8) of the ball(9)of the ball journal (3)and by the other end indirectly or directly on the journal-end terminal collar(11)of the sealing bellows(4) The compression spring element is supported by one end in the region of the transition between the neck region (8) and ball (9) of the ball journal (3) and by the other end indirectly or directly on the journal-end terminal collar (11) of the sealing bellows (4). As a result of the invention, a ball and socket joint is obtained, whereby slipping of the sealing bellows on the ball journal neck is durably and reliably prevented, even under extreme climatic conditions or under extraordinarily high mechanical stress, such as when exposed to the water jet of a pressure washer. The journal-end seal of the sealing bellows and its structural control and dimensional variability are also improved.

Full Text

FORM 2 THE PATENT ACT 1970 (39 of 1970) & The Patents Rules, 2003 COMPLETE SPECIFICATION (See Section 10, and rule 13) 1. TITLE OF INVENTION : BALL JOINT WITH A SEALING BELLOW 2. APPLICANT(S) a) Name : b) Nationality: c) Address : ZF FRIEDRICHSHAFEN AG GERMAN Company 88038 FRIEDRICHSHAFEN GERMANY 3. PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed : - Description The invention relates to a ball and socket joint with sea ling bellows of the type ou timed in the introductory part of claim 1. Ball and socket joints of this type are used on the chassis and on the wheel suspension of motor vehicles, for example, although not exclusively. A ball and socket joint of this type is disclosed in patent specification US 2,397,464, for example. This ball and socket joint has a joint housing and a bearing shell is inserted in the interior of the joint housing to accommodate a joint ball arrangement on a ball journal so that it can effect sliding movements. The bal 1 journal is connected or screwed to the motor vehicle by means of a connector component in the usual way, for example with a lever eye of a connecting rod. In order to prevent moisture and/or dirt from penetrating the bearing region of the ball and socket joint, this known ball and socket joint has a sealing bellows made from an elastomeric material, with two circurnferentially extending annular connecting collars. The sealing bellows is connected to the edge of the joint housing in the stand aid manner by one of the two connecting collars. The other connecting collar likewise sits in the standard manner on the neck or shaft of the ball journal. In conventional ball and socket joints, the searing bellows has a tendency to slip in the region of the connecting collar fitted on the ball journal and shifts from its defined seat on the ball journal, moving onto the joint housing. The sealing bellows and the ball and socket joint are then no longer able to function correctly. In particular, when the sealing bellows is no longer seated correctly, it can then become trapped between the edge of the joint housing and the ball journal or lever eye and becomes damaged as a result. Since the connecting collar of the sealing bellows is then no longer on its defined seat and because the sealing bellows also no longer lies on the lever eye, the sealing function of the sealing bellows is also impaired, which can result in corrosion, firstly in the 2 region of the now exposed shaft region of the ball journal and then between the sealing bellows and ball journal as the sealing function deteriorates further. The fact that moisture and dirt are then able to penetrate the joint region of the ball and socket joint ultimately often leads to increased play in the bearing, impaired movement due to corrosion and even failure of the ball and socket joint. The teaching disclosed in the above mentioned publication US 2,397,464 is intended to counteract the problem of the sealing bellows on the lever eye from slipping and the join of the sealing bellows at the journal end by providing a helical compression spring in the interior of the sealing bellows. The helical compression spring is supported by one end on the edge of the joint housing, whilst the oilier end of the helical compression spring pushes against the relevant connecting collar of the sealing bellows, away from the joint housing in the direction towards the lever eye. Disposing the compression spring between the collar of the sealing bellows and the edge of the joint housing is not really the best solution, however. As a result of this disposition, the compression spring is forced to follow all the pivoting movements of the ball and socket joint and a uniform circumferential contact pressure of the compression spring on the connecting collar is only guaranteed when the ball and socket joint is in the neutral position. In all other angular positions of the ball and socket joint, the contact pressure of the compression spring increases on one side of the circumference of the connecting collar, whilst the contact pressure on the respective oppositely lying side of the connecting collar decreases, which can again impair the correct seating and sealing function of the sealing bellows. Particularly as a result of the uneven and fluctuating degree of contact pressure of the compression spring on the connecting collar of the sealing bellows, it is also necessary to cover and protect the co-operating edge of the sealing bellows separately with a circumferentially extending metal sleeve, according to this publication. This firstly involves extra work and is expensive and secondly impairs the sealing function 3 between the sealing bellows and ball journal. The compression spring is also subjected to dynamic stress with every movement of the ball and socket joint due to the fact that one of its ends is disposed on the joint housing, for which allowance also has to be made when dimensioning the compression spring with a view to durability, making it necessary to use a higher rated compression spring or incurring correspondingly higher costs due to the need to use a higher quality material for the compression spring. Finally, this disposition of the compression spring also significantly limits the maximum possible angular deflection of the ball and socket joint. The reason for this is that when the compression spring is pressed to a block at one side, the joint housing is unable to effect any other angular movement relative to the ball journal in whatever direction it is pivoting. Against this background, the objective of the invention is to propose a ball and socket joint with a sealing bellows, by means of which the disadvantages of the prior art outlined above can be overcome. In particular, the ball and socket joint should be inexpensive to make and at the same time should itself be extremely resistant under extreme climatic conditions. This being the case, slipping of the sealing bellows should be prevented in a simple but effective and durable manner, thereby assuring the sealing function of the sealing bellows in the region of the ball journal on a durable basis. This objective is achieved on the basis of a ball and socket joint incorporating the characterising features defined in claim 1. Preferred embodiments of the subject matter are defined in the dependent claims. The ball and socket joint proposed by the invention comprises a sealing bellows and a joint housing with bearing shell, and the joint ball of a ball journal can be accommodated in the joint housing or in the bearing shell so that it is able to effect sliding movements. The ball journal of the ball and socket joint has a shaft region, a neck region and a ball, and the sealing bellows lies on the surface of the ball journal by 4 means of a circumferentially extending terminal collar in the shaft region of the ball journal. The ball and socket joint proposed by the invention is distinctive due to the fact that an element which is elastic in the journal axial direction is disposed inside the sealing bellows, supported by means of a first abutment surface on the ball journal and a second abutment surface indirectly or directly on the terminal collar of the sealing bellows under pre-tensioning. In other words, this means that for the purpose of the invention, an elastic element is provided, which may be a compression spring element, which in particular is supported on the edge of the joint housing but not in the manner known from the prior art. Instead, the entire compression spring element proposed by the invention is disposed directly on the ball journal and is supported on the ball journal. This offers a whole range of advantages. Firstly, this approach totally eliminates the problem of dynamic load on the compression spring element. As a result of the invention, the compression spring element is biased exclusively statically, in effect. The invention therefore also solves the problem of the uneven distribution of the contact force of the compression spring element in the region of the connecting collar of the sealing bellows in different angular positions of the ball and socket joint. Instead, the contact force of the compression spring element on the connecting collar of the sealing bellows remains uniformly and identically distributed around the entire circumference of the connecting collar under all operating conditions of the ball and socket joint. This is conducive to obtaining a good sealing function of the sealing bellows and is therefore of advantage in terms of the service life of the ball and socket joint. Also as a result of the invention, the relative play of the elastic properties of the sealing bellows and the compression spring element can already be exactly adapted to obtain optimum mechanical properties of the ball and socket joint hand in hand with respective optimum sealing properties of the sealing bellows. In particular, allowance 5 can be made for axial slipping of the sealing bellows and the reducing contact pressure of the terminal end of the sealing bellows on the lever eye over time due to various external or physical influences such as angular deflection of the joint, ageing, relaxation, temperature fluctuations, pressure washers, etc., so as to counteract this exactly by structural means by dimensioning the compression element accordingly. Due to the fact that an exactly definable, constant contact force that is uniform all round presses the journal-end connecting collar of the ball journal in the journal axial direction onto the lever eye as a result of the compression spring element proposed by the invention, the journal-end seal of the sealing bellows can be better controlled and dimensioned by structural means, on the one hand. On the other hand, the axial end face of the journal-end terminal collar of the sealing bellows can be used in a defined manner to achieve the sealing function in particular. Consequently, the axial end face of the terminal collar is also available precisely as a means of providing the journal-end seal between the sealing bellows and ball journal in addition to the radial abutment of this journal-end terminal collar on the shaft of the ball journal. Together, these two sealing planes, in other words the axial abutment of the journal-end terminal collar on the lever eye and the radial abutment of the journal-end terminal collar on the ball journal, enable a significantly better sealing function to be obtained between the sealing bellows and ball journal. This is of particular importance given that this region of the seal represents a particularly critical region of the seal of a ball and socket joint due to the need for relative movement between the sealing bellows and ball journal. Due to the compression spring element proposed by the invention, the casing surface of the sealing bellows is also only required to fulfil the function for which it is actually intended, namely providing a durable sealed and elastic connection for the two bellows seating surfaces on the joint housing and on the ball journal shaft. Without the compression spring element proposed by the invention, the axial force needed to maintain the shape of the sealing bellows and the position of the connecting collars 6 must be applied by the searing bellows itself in most ball and socket joints known from the prior art, and the casing surface of the sealing bellows must therefore be shaped accordingly. It is for this reason that sealing bellows known from the prior art are typically of an onion-type shape. This onion shape results in a relatively short external length of the casing for a relatively large external diameter of the sealing bellows. However, this ratio can be optimised if the sealing bellows is not required to fulfil the function of applying axial forces. This makes for much greater freedom in terms of choosing the shape of the casing surface of the sealing bellows. For example, a specifically cylindrical external shape may be used, in which case the sealing bellows either has a longer length for the same external diameter or a smaller external diameter but the same length. This also enables the shape of the sealing bellows to be more readily adapted to the respective ambient conditions and structural requirements, such as angular deflection or joint mounting space, for example. Since the function of applying axial forces is dispensed with, the thickness of the casing surface of the sealing bellows can also be reduced compared with conventional sealing bellows. The associated reduction in material consumption is just one aspect which has a positive effect on environmental resources and costs. Furthermore, this also reduces the radial tension forces which occur on the journal-end connecting collar of the sea ling bellows during the angular movement of the joint. This also has the effect of reducing the strong fluctuations in forces acting on the radial sealing surface between the bellows and ball journal, which often occur in the prior art, uncoupling them from the angular movements, which again has a positive effect on the service life of the seal and hence the joint as a whole. Another advantage of providing the compression spring element proposed by the invention resides in the fact that existing ball and socket joints can be retrofitted with the system proposed by the invention with virtually no modification to their respective components. To this end, the additional compression spring element merely has to be fitted on the ball journal of an existing ball and socket joint in the manner proposed by 7 the invention. In another embodiment based on the principle behind the invention, a compression spring element elastic in the journal axial direction is provided in the neck region of the ball journal. The compression spring element advantageously has two essentially annular abutment surfaces in the region of its two ends, in which case the compression spring element can be supported in the region of the transition between the neck region and ball of the ball journal by the first abutment surface. By means of the second abutment surface, the sealing bellows can expediently be supported indirectly or directly on the terminal collar. In implementing the invention, the design of the compression spring element and the materials from which the compression spring element is made are not critical, provided whatever compression spring element is used enables the defined, long-term constant force to be applied to the journal-end terminal collar of the sealing bellows. For example, it would also be conceivable to use essentially hollow cylindrical or hollow conical compression spring elements made from elastic polymer materials. In one particularly preferred embodiment of the invention, however, the compression spring element is provided in the form of a steel compression spring. A steel compression spring with a range of different properties but in particular with an exactly specifiable spring constant can be made inexpensively. A compression spring made from steel also has a major advantage in that practically no relaxation occurs in the long term, and the structurally specified contact forces and hence also the sealing properties of at least the axial sealing surface of the sealing bellows remain constant during the entire service life of the ball and socket joint. The invention can also be implemented irrespective of where exactly the compression spring element is supported on the ball journal by means of its ball-end abutment surface, provided the support is provided on the ball journal as proposed by the invention and not on the joint housing, as is the case with the prior art. For example, it 8 would be conceivable for the compression spring clement to be supported on a circumferentially extending annular collar disposed in the neck region of the ball journal. In one preferred embodiment of the invention, however, the compression spring element is supported directly on the joint ball of the ball journal and is so directly at the transition between the neck region and ball of the ball journal. This support directly on the ball is both particularly reliable and also particularly easy to implement in construction terms, because no changes of any kind have to be made to the ball journal. In another embodiment of the invention, a ring element is disposed between the second journal-end abutment surface of the compression spring element and the terminal collar of the sealing bellows. This being the case, the ring element is made, by particular preference, from a tough elastic material with a low coefficient of friction, such as a thermoplastic polyurethane, for example. Such a ring element is of particular advantage if the ball and socket joint is subjected to a frequent or permanent pivoting angular movement. In such a case, sliding movements, which may or may not be permanent, occur both between the journal-end connecting collar of the sealing bellows and the ball journal and between the journal-end abutment surface of the compression spring element and the journal-end connecting collar of the sealing bellows. Depending on the properties of the journal-end abutment surface of the compression spring element, these sliding movements can cause damage to the co-operating complementary surface on the internal face of the sealing bellows in the long term. However, such damage can be easily and advantageously avoided using this ring element. It also facilitates movement of the ball and socket joint and keeps friction between the journal-end connecting collar of the sealing bellows and the ball journal lower. In an alternative embodiment of the invention, the second, in other words journal-end, abutment surface of the compression spring element moves into direct abutment with the terminal collar of the sealing bellows. This embodiment is distinctive due to the 9 simplest conceivable design without any reduction in effectiveness and due to particularly low manufacturing costs. In this instance, any wear of the co-operating abutment surface of the sealing bellows can be prevented, for example by designing the abutment surface of the compression spring element so that it is appropriately smooth or by using a metal reinforcement vulcanised into the sealing bellows, which might possibly be provided in the region of the journal-end terminal collar of the sealing bellows in any event, as an abutment surface for the compression spring element. In another embodiment of the invention, no clamping ring is provided in the region of the journal-end terminal collar of the sealing bellows and/or in the region of the abutment of the sealing bellows on the joint housing. In this connection, the embodiment without a clamping ring in the region of the journal-end terminal collar is particularly preferred. This embodiment has various advantages. Firstly, by dispensing with the clamping ring, savings can be made on both production and assembly costs. Furthermore, the risk of incorrect assembly or damage to the bellows when fitting the clamping ring, which often results in ball and socket joints having to be rejected in the prior art, is totally ruled out. As proposed by the invention, the ball and socket joint has the described compression spring element, by means of which the axial end face of the journal-end terminal collar of the sealing bellows is pressed against the co-operating complementary surface in the region of the lever eye, for example. As described above, this enables an additional active, axial seal to be obtained in the region where the ball journal extends through the sealing bellows, which takes the pressure off the radial seal between the sealing bellows and ball journal. This advantageously also contributes to the option offered by the invention of dispensing with the journal-end clamping ring in particular. In this connection, it is also of advantage if, as is the case with another embodiment of the invention, the axial end face of the journal-end terminal collar of the sealing bellows has a sealing surface based on a construction feature, in particular with a defined sea! geometry such as a seal labyrinth or one or more seal lips, for example. This further 10 improves the sealing function of the axial abutment between the surface in the region of the lever eye and the axial end face of the sealing bellows and can also be controlled on the basis of the construction and selectively influenced. The invention will be explained in more detail below with reference to what are merely examples of embodiments, illustrated in the appended drawings. Of these: Fig. 1 is a schematic diagram showing a side view in section of a first embodiment of a ball and socket joint with a sealing bellows as proposed by the invention; Fig. 2 is a diagram corresponding to that of Fig. 1 but on a larger scale showing the region of the sealing bellows of the ball and socket joint illustrated in Fig. 1; Fig. 3 is a diagram and view corresponding to Fig. 2 illustrating another embodiment of a ball and socket joint proposed by the invention; Fig. 4 is a diagram and view corresponding to Figures 2 and 3 illustrating a third embodiment of a ball and socket joint proposed by the invention; Fig. 5 is a diagram and view corresponding to Figures 2 to 4 illustrating a fourth embodiment of a ball and socket joint proposed by the invention; and Fig. 6 is a diagram and view corresponding to Fig. 1 illustrating a fifth embodiment of a ball and socket joint proposed by the invention. Figure 1 illustrates a first embodiment of a ball and socket joint proposed by the invention. The essential elements of the ball and socket joint may be seen first of all, namely a joint housing 1 with a bearing shell 2 disposed in it, as well as a ball journal 3 and a sealing bellows 4. In what is the top region of the ball journal 3 in the drawing, the ball journal 3 is screwed to the lever eye 5 of a connecting rod 6 or similar, for example. However, position 6 may also be a chassis component, such as a transverse arm for example or an axle component such as a pivot bearing, a wheel support or similar for example. The ball journal 3 is made up of a shaft region 7, neck region 8 and ball 9. As also illustrated, the sealing bellows 4.has two connecting collars 10,11, which form the connections of the sealing bellows 4 in the region of the joint housing 1 and in the 11 shaft region 7 of the ball journal 3. In the embodiment illustrated as an example, the two connecting collars 10, 11 each have a clamping ring 12, 13 which assists the natural elasticity of the sealing bellows 4 and ensures a reliable seating of the connecting collars 10,11 on the joint housing respectively ball journal 3. Finally, Figure 1 also illustrates the compression spring element proposed by the invention, which, in the embodiment illustrated as an example, is provided in the form of a slightly conical helical compression spring 14. The helical compression spring 14 is supported by means of what is its lower abutment surface in the drawing or its bottom end directly in the region of the transition between the neck region 8 and ball 9 of the ball journal 3. By means of what is its upper abutment surface in the drawing or its top end, the helical compression spring 14 presses against a ring element 15, which transmits the pressing force of the helical compression spring 14 to what is the upper connecting collar 11 of the sealing bellows 4 in the drawing. The ring element 15 also protects the connecting collar 11 of the sealing bellows 4 during relative pivoting movements between the ball journal 3 respectively helical compression spring 14 and sealing bellows 4 from damage by what is the upper end of the helical compression spring 14 in the drawing. The pressing action of the helical compression spring 14 prevents the top connecting collar 11 of the sealing bellows 4 from slipping on a permanent basis and with a reliability which can be exactly specified by construction means. The helical compression spring 14 lying completely in the interior of the ball and socket joint is therefore optimally protected and does not even have to be surface-treated to protect against corrosion, again saving on costs. Figure 2 shows a detail on a larger scale from the section through the ball and socket joint illustrated in Figure 1. In addition to a part of the ball journal 3, the sealing bellows 4 secured by the two clamping rings 12,13 as well as the helical compression spring 14 and the ring element 15 are illustrated. As may also be seen from the diagram of Figure 2, the pressing force of the helical compression spring 14 in the region of what is the 12 upper axial end face 16 of the sealing bellows 4 in the drawing provides an additional effective seal for the journal-end connecting collar 11 with respect to the connecting rod 6 in the region of the lever eye 5. This assists and takes the pressure off the radial seal 17 between the connecting collar 11 and the shaft region 7 of the ball journal 3. As illustrated in Figure 3, the journal-end clamping ring 13 (see Figure 2) in particular can be dispensed with, precisely because of the pressing force of the helical compression spring 14 on the journal-end connecting collar 11 of the sealing bellows 4 at 16, which is also of advantage due to the saving on costs. The reason for this is that, because of the pressing force, the axial abutment surface 16 of the sealing bellows 4 already affords a defined seal at the surface of the connecting rod 6, which actively assists the radial sea! 17 of the connecting collar 11 on the shaft 37 of the ball journal 3. Accordingly, the cooperating clamping ring 13 can also be dispensed with, without reducing the sealing function at 16,17 compared with a ball and socket joint which does not incorporate the compression spring element 14 proposed by the invention. In the embodiment illustrated in Figure 3, the housing-end clamping ring 12 (see Figure 2) has been dispensed with in addition to the journal-end clamping ring 13 (see Figure 2). In the embodiment illustrated in Figure 3, its function is assumed by an annular circumferentially extending metal sleeve 18 vulcanised into the housing-end connecting collar 10. The metal sleeve 18 affords a defined and durably fixed seating for the housing-end connecting collar 10 on the joint housing 1. An even simpler embodiment in terms of the design of the compression spring arrangement proposed by the invention is illustrated in Figure 4. As illustrated, the ring element 15 (see Figure 3) has also been omitted in the embodiment illustrated in Figure 4. This reduces the number of modifications which have to be made to the ball and socket joint in order to incorporate the helical compression spring 14 in addition when implementing the invention. A metal sleeve 19 vulcanised into the journal-end connecting collar 11, which may optionally be provided in any event, can therefore completely replace the function of the omitted ring element 15 because the helical 13 compression spring 14 lies against the vulcanised metal sleeve 19. This also reliably prevents damage or wear to the journal-end connecting collar 11 due to relative pivoting movements between the ball journal 3 respectively helical compression spring 14 and sealing bellows 4. Figure 5 illustrates another embodiment of a ball and socket joint proposed by the invention. The embodiment illustrated in Figure 5 is very similar to the embodiment illustrated in Figure 2 and primarily differs from it due to a raceway 20 with an L-shaped cross-section. The raceway 20, which is made from corrosion-resistant stainless steel for example, is disposed between the journal-end seal collar 11 of the sealing bellows 4 and the bearing surface 17 in the shaft region 7 of the ball journal 3 or in the region of the end face 16 on the lever eye 5. The purpose of the raceway 20 is to guide the journal-end connecting collar of the sealing bellows exactly and smoothly. Particularly in the case of ball and socket joints effecting particularly frequent or permanent pivoting angular movements, the raceway 20 prevents any potentially abrasive chafing of the journal-end connecting collar on the ball journal shaft 17 or on the connecting component 6 at 16. Here too, the compression spring element 14 proposed by the invention ensures a permanent defined axial abutment of the raceway 20 on the co-operating component, in this instance on the connecting component 6, for example the lever eye. Figure 6, finally, illustrates another embodiment of the ball and socket joint with a sealing bellows and compression spring element 14 proposed by the invention. As illustrated, the ball and socket joint illustrated in Figure 6 specifically differs from the ball and socket joint illustrated in Figure 1 due to the fact that the ball and socket joint illustrated in Figure 6 firstly has a folding bellows 21 and secondly has a two-part ball journal 3. The two-part ball journal 3 is made up of journal element 22 and ball element 23, which are pressed to one another. However, the invention offers particular advantages precisely in applications which use a folding bellows 21 and/or a ball and socket joint with a two-part ball journal 3. 14 The reason for this is that a folding bellows 21 firstly has the advantage of particularly high flexibility with particularly low rebound forces but is secondly distinctive due to particularly low axial forces. This makes it necessary to secure the journal-end connecting collar 11 of the folding bellows 21 particularly effectively and carefully to protect against undesired axial slipping on the shaft 7 or neck 8 of the ball journal 3.1 n the case of the prior art, this is usually done by guiding the journal-end connecting collar 11 of the folding bellows 21 axially at both ends by means of a groove recessed into the shaft region 7 of the ball journal 3 at 11. However, making the journal groove and fitting the connecting collar 11 in the groove involves more work, incurs extra costs and represents a potential source of error during production. Due to the fact that the journal-end connecting collar 11 of the folding bellows 21 can be axially supported in a durable and exactly dimensioned manner due to the invention, the journal groove that has been need ed in the past can be replaced by a simple axial stop or shoulder 24. The axial shoulder 24 totally takes over, in conjunction with the effect of the compression spring element 14, the function of the journal groove needed in the past. This is of particular advantage in the case of the ball and socket joint illustrated in Figure 6 with a two-part ball journal 3,22, 23. By replacing the journal groove used to date, which had to be machined by removing material, with the co-operating effects of the axial shoulder 24 and compression spring element 14, the journal element 22 of the ball journal 3 can now be made completely in a single piece without removing material, which both saves on manufacturing costs and improves the quality and load-bearing capacity of the ball journal 3. As a result, it is clear that the reliability and failsafe properties of ball and socket joints can be improved in a totally surprisingly elementary, simple and cost-reducing manner due to the invention. Accordingly, as a result of the invention, slipping of the sealing bellows itself is permanently prevented, even under extreme climatic conditions or under extraordinary stress, such as when subjected to the water jet of a pressure washer, 15 for example. The invention therefore makes a significant contribution to reducing maintenance, improving service life, smoothness and reliability of ball and socket joints, especially in demanding applications on motor vehicles. 16 List of reference numbers 1 Joint housing 2 Bearing shell 3 Ball journal 4 Sealing bellows 5 Lever eye or connecting component 6 Connecting rod 7 Shaft region 8 Neck region 9 Ball 10 Housing-end connecting collar 11 Journal-end connecting collar 12 Housing-end clamping ring 13 Journal-end clamping ring 13 Helical compression spring 15 Ring element 16 End face 17 Radial seal surface 18 Metal sleeve 19 Metal sleeve 20 Raceway 21 Folding bellows 22 Journal element 23 Ball element 24 Axial shoulder 17 WE CLAIM: 1. Ball and socket joint with sealing bellows (4), which ball and socket joint comprises a joint housing (1) with bearing shell (2), in which the joint ball (9) of a ball journal (3) can be accommodated so that it can effect sliding movements, the ball journal (3) comprising a shaft region (7), a neck region (8) and a ball (9), and the sealing bellows (4) has a circumferentially extending terminal collar (11) which lies indirectly or directly against the shaft region (7) of the ball journal (3), characterised in that an element (14) that is elastic in the journal axial direction is disposed inside the sealing bellows (4) supported by means of a first abutment surface on the ball journal (3) and by means of a second abutment surface indirectly or directly on the terminal collar (11) of the sealing bellows (4) under pre-tensioning. 2. Ball and socket joint as claimed in claim 1, characterised in that the element (14) is a compression spring element. 3. Ball and socket joint as claimed in claim 2, characterised in that the compression spring element (14) is a heli compression spring (14) made from steel. 4. Ball and socket joint as claimed in one of the preceding claims, characterised in that the element (14) has a respective annular abutment surface in the region of one of its two ends. 5. Ball and socket joint as claimed in one of the preceding claims, characterised in that the element (14) lies with one of its abutment surfaces in the region of the transition between the neck region (8) and ball (9) or directly on the ball (9) of the ball journal (3). 6. Ball and socket joint as claimed in one of the preceding claims, 18 characterised in that the sealing bellows (4) lies with the circumferentially extending terminal collar (11) against the surface (17) of the ball journal (3). 7. Ball and socket joint as claimed in one of the preceding claims, characterised in that a ring element (15) is disposed between the second abutment surface of the element (14) and the terminal collar (11) of the sealing bellows (4). 8. Ball and socket joint as claimed in claim 8, characterised in that the ring element (15) is made from a tough elastic material with a low coefficient of friction, for example a thermoplastic polyurethane. 9. Ball and socket joint as claimed in one of claims 1 to 7, characterised in that the second abutment surface of the element (14) moves into abutment directly on the terminal collar (11) of the sealing bellows (4). 10. Ball and socket joint as claimed in one of the preceding claims, characterised in that a clamping ring (12,13) is provided in the region of the terminal collar (11) of the sealing bellows (4) on the ball journal shaft (7) and/or in the region of the abutment of the sealing bellows (4) on the joint housing (1). 11. Ball and socket joint as claimed in one of the preceding claims, characterised in that the end face (16) of the journal-end terminal collar (11) of the sealing bellows (4) has a seal surface (16).. HIRAL CHANDRAKANT JOSH I AGENT FOR ZF FRIEDRICHSHAFEN AG Dated this 14th day of March, 2007 19 ABSTRACT The invention relates to a ball and socket joint with sealing bellows (4), which sealing bellows (4) lies against the surface (17) of the ball journal (3) in the shaft region (7) of the ball journal (3) by means of a circumferentially extending terminal collar (11). The ball and socket joint proposed by the invention is distinctive due to the fact that an element (14) elastic in the journal axial direction in the form of a compression spring element is disposed in the neck region (8) of the ball journal (3). The compression spring element is supported by one end in the region of the transition between the neck region (8) and ball (9) of the ball journal (3) and by the other end indirectly or directly on the journal-end terminal collar (11) of the sealing bellows (4). As a result of the invention, a ball and socket joint is obtained, whereby slipping of the sealing bellows on the ball journal neck is durably and reliably prevented, even under extreme climatic conditions or under extraordinarily high mechanical stress, such as when exposed to the water jet of a pressure washer. The journal-end seal of the sealing bellows and its structural control and dimensional variability are also improved. To, The Controller of Patents, The Patent Office, 20 Mumbai

Documents:

390-mumnp-2007-abstract(granted)-(7-5-2010).pdf

390-mumnp-2007-abstract.doc

390-mumnp-2007-abstract.pdf

390-mumnp-2007-cancelled pages(19-1-2010).pdf

390-MUMNP-2007-CLAIMS(AMENDED)-(11-3-2010).pdf

390-MUMNP-2007-CLAIMS(AMENDED)-(19-1-2010).pdf

390-mumnp-2007-claims(granted)-(7-5-2010).pdf

390-mumnp-2007-claims.doc

390-mumnp-2007-claims.pdf

390-MUMNP-2007-CORRESPONDENCE(11-3-2010).pdf

390-MUMNP-2007-CORRESPONDENCE(18-1-2010).pdf

390-MUMNP-2007-CORRESPONDENCE(21-7-2009).pdf

390-mumnp-2007-correspondence(26-6-2007).pdf

390-mumnp-2007-correspondence(ipo)-(13-5-2010).pdf

390-mumnp-2007-correspondence-ohters.pdf

390-mumnp-2007-correspondence-received.pdf

390-mumnp-2007-descripiton (complete).pdf

390-mumnp-2007-description(granted)-(7-5-2010).pdf

390-mumnp-2007-drawing(granted)-(7-5-2010).pdf

390-mumnp-2007-drawings.pdf

390-MUMNP-2007-FORM 1(21-7-2009).pdf

390-mumnp-2007-form 1(26-6-2007).pdf

390-mumnp-2007-form 2(granted)-(7-5-2010).pdf

390-MUMNP-2007-FORM 2(TITLE PAGE)-(21-7-2009).pdf

390-mumnp-2007-form 2(title page)-(granted)-(7-5-2010).pdf

390-mumnp-2007-form 26(15-3-2007).pdf

390-mumnp-2007-form 26(28-5-2007).pdf

390-MUMNP-2007-FORM 3(18-1-2010).pdf

390-MUMNP-2007-FORM 3(21-7-2009).pdf

390-mumnp-2007-form-1.pdf

390-mumnp-2007-form-18.pdf

390-mumnp-2007-form-2.doc

390-mumnp-2007-form-2.pdf

390-mumnp-2007-form-3.pdf

390-mumnp-2007-form-5.pdf

390-mumnp-2007-form-pct-ib-301.pdf

390-mumnp-2007-form-pct-ib-304.pdf

390-mumnp-2007-form-pct-isa-237.pdf

390-mumnp-2007-form-pct-ro-101.pdf

390-MUMNP-2007-OTHER DOCUMENT(21-7-2009).pdf

390-MUMNP-2007-PCT-IB-373(21-7-2009).pdf

390-MUMNP-2007-PCT-ISA-210(21-7-2009).pdf

390-mumnp-2007-pct-search report.pdf

390-MUMNP-2007-PETITION UNDER RULE 137(18-1-2010).pdf

390-MUMNP-2007-REPLY TO HEARING(19-1-2010).pdf

390-mumnp-2007-wo international publication report(15-3-2007).pdf

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