PLUG-IN COUPLING WITH TOLERANCE COMPENSATION

Abstract

A coupling seat provides a seat space in which the coupling head of a coupling bolt can be releasably locked and moved linearly in the seat space. The seat has a wall that surrounds the seat space, and the dome has a locking structure to fasten the coupling seat in an installation opening in a component. The seat has an open end and a closed end with a locking structure for the head of the coupling bolt. The locking structure of the dome comprises latching bars that are arranged opposite each other on an inner wall of the seat space and parallel to a longitudinal axis of an inner dome cross-section and form an undercut opposite the insertion direction. The locking structure permits movement of a coupling bolt along the latching bars in the seat space transverse to the insertion direction.

Claims

1. A coupling seat designed as a single part which can be locked into a slot-shaped installation opening of a component and provides a seat space in which the coupling head of a coupling bolt can be releasably locked and, when in a locked state, can be moved linearly in the seat space, and has the following features: a. a closed peripheral wall of a cupola-like dome surrounds the seat space of the coupling head of the coupling bolt, wherein the dome has an outer locking structure to fasten the coupling seat in the installation opening of the component, an open end with a slot-shaped insertion opening for inserting the coupling head of the coupling bolt in an insertion direction R.sub.E and a closed end with an inner locking structure adjacent thereto for the coupling head of the coupling bolt, b. a slot-shaped opening cross-section of the insertion opening, as well as a slot-shaped inner dome cross-section of the seat space, each perpendicular to the insertion direction R.sub.E, are defined by a longitudinal axis and a shorter transverse axis running transverse thereto, and c. the inner locking structure of the cupola-like dome comprises only two inner latching bars that are arranged opposite each other on an inner wall of the seat space and run parallel to the longitudinal axis of the inner dome cross-section, have a distance D.sub.56 with respect to each other and form an undercut opposite the insertion direction R.sub.E, wherein the seat space has in the insertion direction R.sub.E above and below the inner latching bars parallel to the shorter transverse axis a width B.sub.40, wherein the shorter axis extends transverse, and for the spacing D.sub.56 of the inner latching bars it applies:
0.65.Math.B.sub.40≤D.sub.56≤0.9.Math.B.sub.40, d. the inner locking structure does not comprise latching bars parallel to the transverse axis of the inner dome cross-section, and permits movement of a locked coupling bolt along the inner latching bars in the seat space transverse to the insertion direction R.sub.E.

2. The coupling seat according to claim 1, the insertion opening of which has a peripheral flange running around the insertion opening which projects radially outward and comprises a contact surface transverse to the insertion direction. (Previously Presented) The coupling seat according to claim 2, which comprises a sealing ring that is arranged on the contact surface of the peripheral flange.

4. The coupling seat according to claim 1 in which the inner latching bars of the inner locking structure have an approach bevel facing the insertion opening and a latching bevel facing away from the insertion opening, and an angle of inclination of the approach bevel relative to the insertion direction is smaller than an angle of inclination of the latching bevel relative to the insertion direction R.sub.E.

5. The coupling seat according to claim 2, the outer locking structure of which is formed by at least two outer latching bars arranged opposite each other that run parallel to the longitudinal axis of the inner dome cross-section and are arranged adjacent to the peripheral flange of the insertion opening.

6. The coupling seat according to claim 5 in which the outer latching bars of the outer locking structure have an approach bevel facing away from the peripheral flange, and a latching bevel facing the peripheral flange, and an angle of inclination of the approach bevel relative to the insertion direction is smaller than an angle of inclination of the latching bevel relative to the insertion direction.

7. The coupling seat according to claim 5 in which a distance between a bottom edge of the outer latching bar facing the flange and an inner top edge of the inner latching bar facing away from the flange is greater than or equal to an inner spacing of the peripheral wall parallel to the transverse axis of the dome cross-section in the seat space of the coupling head.

8. A plug-in coupling with a coupling seat according to claim 1 and a coupling bolt with a coupling head that can be locked in the coupling seat.

9. The plug-in coupling according to claim 8, the coupling bolt of which has two bars or wings that are arranged diametrical to each other axially below the coupling head and that, within the coupling seat, block a shift of the locked coupling head parallel to the longitudinal axis of the dome cross-section.

10. A connection of a first component with at least one slot-shaped installation opening in which the coupling seat according to claim 1 is fastened, and a second component to which at least one coupling bolt with a coupling head is fastened by a fastening end facing away from the coupling head.

11. The connection according to claim 10 in which the second component has at least two coupling bolts, of which one coupling bolt has bars or wings that are arranged diametrical to each other axially below the coupling head and block a shift within the coupling seat of the locked coupling head parallel to the longitudinal axis of the dome cross-section in order to form a connection with a constant position of the second component with respect to the first component.

12. A production method for a coupling seat according to claim 1, having the following steps: Provide an injection mold with the complementary features with regard to the coupling seat, Injection mold the coupling seat in the provided injection mold, and Demold the coupling seat from the injection mold.

13. The production method according to claim 12, in which the coupling seat is made of a hard rubber or a hard plastic that has a lower elasticity than normal elastomers.

14. The coupling seat according to claim 2 in which the inner latching bars of the inner locking structure have an approach bevel facing the insertion opening and a latching bevel facing away from the insertion opening, and an angle of inclination of the approach bevel relative to the insertion direction is smaller than an angle of inclination of the latching bevel relative to the insertion direction R.sub.E.

15. The coupling seat according to claim 3 in which the inner latching bars of the inner locking structure have an approach bevel facing the insertion opening and a latching bevel facing away from the insertion opening, and an angle of inclination of the approach bevel relative to the insertion direction is smaller than an angle of inclination of the latching bevel relative to the insertion direction R.sub.E.

16. The coupling seat according to claim 3, the outer locking structure of which is formed by at least two outer latching bars arranged opposite each other that run parallel to the longitudinal axis of the inner dome cross-section and are arranged adjacent to the peripheral flange of the insertion opening.

17. The coupling seat according to claim 16 in which the outer latching bars of the outer locking structure have an approach bevel facing away from the peripheral flange, and a latching bevel facing the peripheral flange, and an angle of inclination of the approach bevel relative to the insertion direction is smaller than an angle of inclination of the latching bevel relative to the insertion direction.

18. The coupling seat according to claim 16 in which a distance between a bottom edge of the outer latching bar facing the flange and an inner top edge of the inner latching bar facing away from the flange is greater than or equal to an inner spacing of the peripheral wall parallel to the transverse axis of the dome cross-section in the seat space of the coupling head.

19. The coupling seat according to claim 14, the outer locking structure of which is formed by at least two outer latching bars arranged opposite each other that run parallel to the longitudinal axis of the inner dome cross-section and are arranged adjacent to the peripheral flange of the insertion opening.

20. The coupling seat according to claim 19 in which the outer latching bars of the outer locking structure have an approach bevel facing away from the peripheral flange, and a latching bevel facing the peripheral flange, and an angle of inclination of the approach bevel relative to the insertion direction is smaller than an angle of inclination of the latching bevel relative to the insertion direction.

Description

4. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The embodiments of the present disclosure are explained in greater detail in reference to the accompanying drawing. In the figures:

[0043] FIG. 1 shows a perspective view of a plug-in coupling with a coupling seat, sealing ring, and coupling bolt with a shaft with a round cross-section,

[0044] FIG. 2 shows an embodiment of the coupling bolt with two bars or wings arranged diametrical to each other,

[0045] FIG. 3a) shows a sectional view of an embodiment of the plug-in coupling with a coupling seat and coupling bolt parallel to the transverse axis of the dome cross-section of the coupling seat,

[0046] FIG. 3b) shows a sectional view of another embodiment of the plug-in coupling with a coupling seat and coupling bolt parallel to the transverse axis of the dome cross-section of the coupling seat,

[0047] FIG. 3c) shows a sectional view of another embodiment of the plug-in coupling with a coupling seat and coupling bolt parallel to the transverse axis of the dome cross-section of the coupling seat,

[0048] FIG. 4 shows a section along the line B-B from FIG. 3,

[0049] FIG. 5a) shows a section along line B-B from FIG. 3 of a coupling seat in which a coupling bolt is inserted with support wings or support bars arranged opposite one another,

[0050] FIG. 5b) shows another embodiment of the coupling bolt with two bars or wings arranged diametrical to each other,

[0051] FIG. 6 shows an outside view of an embodiment of the coupling seat,

[0052] FIG. 7 shows another outside view of a coupling seat,

[0053] FIG. 8 shows an outside view of the coupling seat from FIG. 7 with a sealing ring,

[0054] FIG. 9 shows a perspective view of the coupling seat with a sealing ring,

[0055] FIG. 10 shows a sectional view according to FIG. 3 without a component and without an installed coupling bolt,

[0056] FIG. 11 shows a sectional view according to FIG. 4 without a component and without an installed coupling bolt, and

[0057] FIG. 12 shows a flowchart of an embodiment of the production method of the coupling seat.

5. DETAILED DESCRIPTION

[0058] FIG. 1 shows an exploded view of an embodiment of the plug-in coupling 1. This consists of a coupling bolt 10 and a coupling seat 30. In various embodiments of the plug-in coupling 1, the coupling seat 30 is combined with a sealing ring 70.

[0059] A first component B1 and a second component B2 are easily releasably connected to each other by the plug-in coupling 1. An example of such connections is the fastening of add-on parts such as lights, panels, etc. to the body of a motor vehicle. Depending on the design and size of the add-on parts, they are fastened with the assistance of one or more plug-in couplings 1. Correspondingly, a plurality of installation openings 80 may be provided in the first component B1 in each of which the coupling seat 30 is locked. The coupling seat 30 may be fixed securely in the installation opening 30, such as by adhesive bonding.

[0060] The second component B2 is equipped with at least one coupling bolt 10. To establish a connection, this is introduced into the coupling seat 30 and locked there. For such a connection, the combination of the coupling seat 30 and the coupling bolt 10 may be when tolerances should be compensated for between the connected components B1 and B2. Due to the round the shaft 12, the coupling bolt 10 is able to execute linear compensation movements within the coupling seat 30 in order to compensate for tolerances. Such a connection with the property of permitting compensation movements between the connected components B1, B2 is termed a floating bearing.

[0061] It is also of practical importance to connect two components B1, B2 to each other by means of at least one fixed bearing. In this case, the plug-in coupling 1′ consisting of the coupling seat 30 and a further embodiment of the coupling bolt 10′ do not permit a relative movement between the coupling seat 30 and the coupling bolt 10′ when both are in a locked state. As can be seen in FIG. 2, the coupling bolt 10′ for a fixed bearing as well as the coupling bolt 10 has a coupling head 14, a shaft 12, and a fastening end 16 on the shaft 12.

[0062] Additionally, two wings or bars 18 may extend from the shaft 12 in a diametrically opposed arrangement. The wings or bars 18 are arranged in the direction of a potential shift direction of the coupling bolt 10′ within the coupling seat 30. In this manner, a compensation movement of the coupling bolt 10′ within the coupling seat 30 is prevented that would be possible for the coupling bolt 10 within the coupling seat 30. In this manner, the connection consisting of the coupling seat 30 and coupling bolt 10′ with wings 18 forms a fixed bearing of the two components B1, B2 connected to each other.

[0063] According to further embodiments, e.g. elongated second components B2 are exposed to lengthwise longitudinal fluctuations due to thermal stresses which require a connection to the first component B1 with a tolerance compensation. At the same time, it should however also be ensured that the second component B2, which may be an elongated taillight with a length within a range of 1-2 m is reliably immovably fastened at a specific position to the body. Consequently, components B2 subjected to tolerances are connected by at least two plug-in couplings 1 which form a floating bearing and a fixed bearing (see above). Correspondingly, an elongated taillight as the second component B2 may be equipped with a plurality of coupling bolts 10, 10′, of which one coupling bolt 10′ comprises the wing 18. This defines the fixed fastening position of the taillight, whereas tolerances in the connection by the plug-in coupling 1 consisting of the coupling bolt 10 and the coupling seat 30 are compensated for.

[0064] To illustrate a fixed bearing, FIG. 5a shows a coupling bolt 10′ with wings 18 that is locked in the coupling seat 30. It can be seen that the wings 18 terminate transversely to the insertion direction R.sub.E of the coupling bolt 10′ in the coupling seat 30 directly adjacent to an inner wall 32 of the coupling seat 30. Consequently, compensation movements of the coupling bolt 10′ transverse to the insertion direction R.sub.E within the coupling seat 30 are prevented.

[0065] FIG. 5b shows an alternative configuration of the coupling bolt 10″. In this design, the wings 18′ have a shorter axial extension in comparison to FIG. 5a. In order to nonetheless be able to block a movement of the coupling bolt 10″ within the seat space 40 of the coupling seat 30 using the wings 18″, the shaft 12′ is designed with a slot-shaped cross-section. The longer side of the slot-shaped cross-section of the shaft 12′ runs parallel to the longitudinal axis L.sub.42 of the dome cross-section 42.

[0066] Surface segments F.sub.12 and F.sub.14 may be arranged on the shaft 12′ and/or on the head 14′ (see FIG. 5b) that run parallel to the longitudinal axis L.sub.42. According to a further configuration, the thickness of the shaft 12′ parallel to the transverse axis Q.sub.42 corresponds to the transverse width B.sub.40 of the seat space 40. If the coupling bolt 10″ is locked in the coupling seat 30, the surface segments F.sub.12 and F.sub.14 abut the inner wall 32 of the coupling seat 30. The precisely fitting connection may support the retention force and may realize an integrated form fit between the coupling seat 30 and coupling bolt 10″.

[0067] The connection of a floating bearing is shown in FIG. 3a-c and FIG. 4. The coupling bolt 10 arranged in the coupling seat 30 may be able to carry out compensation movements A there, transverse to the insertion direction R.sub.E. This does not impair or loosen the connection between the coupling bolt 10 and the coupling seat 30.

[0068] The coupling seat 30 in FIG. 1 is shown in an enlarged perspective view in FIG. 9. Lateral representations can be found in FIGS. 6 to 8.

[0069] The coupling seat 30 comprises a closed, peripheral wall 35 without penetrations that forms the inner wall 32 and the outer wall 34. Viewed in the insertion direction R.sub.E, the peripheral wall 35 first defines a slot-shaped insertion opening 36. The coupling bolt 10; 10′ is inserted through the insertion opening 36 into the coupling seat 30 and locked there.

[0070] Due to the slot-shaped design of the insertion opening 36, an opening cross-section P of the insertion opening 36 can be described by a longitudinal axis L.sub.36 and a shorter transverse axis Q.sub.36. Moreover, the peripheral wall 35 defines a dome with an inner seat space 40 and a closed end 38 of the coupling seat 30. The inner seat space 40 is qualified by a slot-shaped dome cross-section 42 transverse to the insertion direction R.sub.E. The dome cross-section 42 is also defined by a longitudinal axis L.sub.42 and a transverse axis Q.sub.42. According to a further embodiment, the dome cross-section 42 substantially corresponds to the opening cross-section P of the insertion opening 36. The peripheral wall 35 with the inner wall 32 extends almost perpendicular to the flange 50 which surrounds the insertion opening 36.

[0071] The flange 50 may extend to the outside perpendicular to the outer wall 34, and forms a first and a second contact surface 52, 54. The first contact surface 52 may serve as a support surface in a connection of the coupling seat 30 to the first component B1. Once the coupling seat 30 has been inserted into the slot-shaped installation opening 80, the first contact surface 52 abuts the first component B1.

[0072] In this context, a seal, in particular a sealing ring 70, may be arranged between the flange 50 and the first component B1. The sealing ring 70 is compressed between the first contact surface 52 of the flange 50 and the first component B1 in order to realize a connection which may be liquid-tight and sealed against contamination between the coupling seat 30 and the first component B1.

[0073] The peripherally arranged sealing ring 70 may consist of foam rubber, rubber, silicone, or another suitable sealing material.

[0074] In order to not overload the arranged sealing ring 70 in a compressed state between the contact surface 52 and the first component B1, contact bars 53 may be provided on the flange 50. The contact bars 53 extend from the contact surface 52 in the insertion direction R.sub.E. Two contact bars 53 which may be arranged opposite each other are provided parallel to the longitudinal axis L.sub.36 of the insertion opening 36. Other contact bars parallel to the transverse axis Q.sub.36 or a contact bar 53 surrounding the flange 50 may be arranged.

[0075] The contact bars 53 abut the first component B1 in the connection between the coupling seat 30 and the first component B1. The sealing ring 70 may have a thickness in the insertion direction R.sub.E that is greater than the length of the contact bar 53 in the insertion direction R.sub.E. The sealing ring 70 is thereby sealingly compressed in the connection, but not overloaded or damaged by the connection.

[0076] The contact bar 53 may yield laterally upon excessive mechanical stress in the connection to the component B1. A mechanical overload of the flange 50 and coupling seat 30 is thereby avoided.

[0077] If the coupling seat 30 is inserted into the slot-shaped installation opening 80, it locks there with the assistance of the outer locking structure. The outer locking structure comprises outer latching bars 44 that run parallel to the longitudinal axis L.sub.36, L.sub.42 of the opening cross-section P and the dome cross-section 42, and are arranged opposite each other.

[0078] The outer latching bars 44 have an approach bevel 46 which an edge of the installation opening 80 approaches when inserting the coupling seat 30 into the installation opening 80. Moreover, the latching bar 44 has a latching bevel 48, behind which, or respectively against which, the edge of the installation opening 80 of the first component B1 locks.

[0079] As for example can be seen from FIG. 10, an angle of inclination a of the approach bevel 46 is smaller than an angle of inclination B of the latching bevel 48. This geometric design ensures that an installation force for locking the coupling seat 30 across the approach bevel 46 in the installation opening 80 is smaller than a releasing force to release the coupling seat 30 across the latching bevel 48 from the installation opening 80.

[0080] Analogous to the outer locking structure, an inner locking structure is provided in the seat space 40 of the coupling seat 30 to releasably lock the coupling bolt 10; 10′. The inner locking structure comprises two latching bars 56 arranged opposite each other. The latching bars 56 may run parallel to the longitudinal axis L.sub.36, L.sub.42 of the insertion opening 36 or the dome cross-section 42. Moreover, the inner latching bars 56 each have an approach bevel 58 facing the insertion opening 36. On the side of the inner latching bars 56 facing away from the insertion opening 36, a latching bevel 60 is provided for the coupling bolt 10; 10′. Analogous to the outer latching bars in 44, an angle of inclination y of the approach bevel 58 is smaller than an angle of inclination δ of the latching bevel 60.

[0081] Accordingly, the installation or connecting force of the coupling bolt 10; 10′ to overcome the approach bevel 58 may be smaller than a releasing force to overcome the latching bevel 60. Consequently, the strength of the connection between the coupling bolt 10; 10′ and the coupling seat 30 may be adjusted by the angle of inclination δ of the latching bevel 60.

[0082] According to another embodiment, the strength of the connection between the coupling bolt 10; 10′ and the coupling seat 30 can be adjusted by the distance D.sub.56 between the inner latching bars 56 arranged opposite each other. While the connection is being released, the coupling head 14 with its head diameter presses the inner latching bars 56 outward against the retaining force of the wall 35 and pass it. Due to the highly elastic material of the coupling seat 30, the coupling head 14 does not in so doing elastically press into the wall 35. The seat space 40 may have a width B.sub.40 in the insertion direction R.sub.E above the inner latching bars 56 parallel to the transverse axis Q.sub.42, Q.sub.36. According to a further embodiment, the width B.sub.40 corresponds to a diameter of the coupling head 14. In order to set the releasing force of the coupling head 14 from the coupling seat 30 sufficiently high, the following may hold true for the spacing D.sub.56 of the inner latching bars 56:

0.65.Math.B.sub.40≤D.sub.56≤0.9.Math.B.sub.40,

or 0.78.Math.B.sub.40≤D.sub.56≤0.82.Math.B.sub.40.

[0083] Corresponding to the aforementioned dimensions, the coupling head 14 may be held in the coupling seat 30 in a friction lock and form fit when the diameter of the coupling head corresponds to or is greater than the width B.sub.40.

[0084] The guidance of the coupling head 14 in the seat space 40 may provide a centering of the coupling head 14 in the seat space 40. In this case, the distance D.sub.56 between the latching bars 56 is the same as the inner wall distance B.sub.40 in the seat space 40 so that the inner latching bars 56 do not exist.

[0085] In a further connection of the two components B1, B2 by means of at least two plug-in couplings, e.g. a coupling seat 30 with the dimension D.sub.56<B.sub.40 creates a force fit and a form fit connection which can be designed as a fixed or floating bearing. This connection is sufficient for the specific positioning and/or arrangement of the two components B1, B2 relative to each other. Correspondingly, the second plug-in connection with the coupling seat 30 without inner latching bars 56, i.e., D.sub.56=B.sub.40, serves as a guide for the coupling bolt 10 in the event of tolerances, etc. that arise.

[0086] In order to support the load transfer between the coupling bolt 10 and the adjacent inner wall 32, the coupling head 14 and the shaft 12 may be equipped with flattened surface segments F.sub.14, F.sub.16 instead of the round shape. These may run parallel to the longitudinal axis L.sub.42 and lie against the inner wall 32 in the connection to transfer load.

[0087] To insert and release the coupling head 14 from the coupling seat 30, the coupling head 14 presses the sections of the wall 35 with the inner latching bars 56 outward. According to a further embodiment of the coupling seat 30, it does not consist of an elastically deformable material like elastomer. Such an elastic material would not offer sufficient retention for the coupling bolt 10; 10′ in the event of frequent load changes between the two components B1, B2 so that the connection could release.

[0088] Consequently, the coupling seat 30 may be made from a hard elastic material with an elasticity modulus of E≥1000 MPa. This material property of thermoplastics is known at room temperature and lower temperatures, i.e., generally below the softening range. The coupling seat 30 may be injection molded from polyamide.

[0089] According to various material configurations, the coupling seat 30 may consist of polyamide, polyamide PA 66, polyamide with a fiberglass component, PA66 with a fiberglass component, and POM (polyoxymethylene). In this case, other plastics are also useful that have similar properties.

[0090] The coupling bolts 10, 10′, 10″ may consist of metal or plastic. A plastic may be PPA (polyphthalamide) with or without fiberglass reinforcement (GF), which may be PPA-GF 50.

[0091] Since the coupling seat 30 may consist of a hard elastic material such as hard plastic or hard rubber, the coupling head 14 cannot release from the coupling seat 30 by elastic material deformation. Instead, a wall length 65 is sufficiently large so that the wall 35 can bulge outward despite the support in the installation opening 80. The wall length 65 extends from the latching bevel 48 which abuts the first component B1. The wall length 65 may terminate at the latching bevel 60 abutted by the coupling head 14. The wall section 65 between the bottom edge of the outer latching bar 44 facing the flange 50 and a top edge of the inner latching bar 56 facing away from the flange 50 and lying on the inside may be greater than or equal to an inner distance B 40 of the peripheral wall 32 parallel to the transverse axis Q 42 of the dome cross-section 42 in the seat space 40.

[0092] Once the coupling bolt 10 is inserted into the coupling seat 30 and is locked there in the seat space 40, it is held in this position by the inner latching bars 56. This can be seen in FIGS. 3a to 3c.

[0093] According to a further embodiment, the coupling head 14 locks in the insertion direction R.sub.E within the seat space 40 above the inner latching bars. In so doing, the inner latching bars 56 engage in the recess 13 in the coupling bolt 10. According to the configuration shown in FIG. 3a, the shaft 12 of the coupling bolt 10 may be designed undersized in comparison to the inner width B.sub.40 of the coupling seat 30. This available clearance of the shaft 12 in the coupling seat 30 supports the mobility of the coupling bolt in the coupling seat 30.

[0094] In order to avoid a mechanical load on the coupling seat 30 or wear thereof, or in order to more securely hold the coupling bolt 10 in comparison to FIG. 3a, the dimensions of the shaft 12 are adapted to the inner width B.sub.40. For this, the shaft 12 is shaped to tightly fit as shown in FIG. 3c. There, a shaft diameter D.sub.12 is the same as the inner width B.sub.40 of the seat space 40 parallel to the transverse axis.

[0095] Alternatively to this (see FIG. 3c), the shaft 12 has a radial shaft thickening 11. The shaft thickening 11 abuts the inner wall 32 of the coupling seat 30 in the same way as the shaft 12 from FIG. 3b.

[0096] With the assistance of the configurations in FIGS. 3b and 3c and the precisely fitting arrangement of the coupling bolt 10 in the coupling seat 30 shown therein, an advantageous, flat or areal load transfer between the coupling bolt 10 and coupling seat 30 may be realized. This ensures an integrated form fit between the coupling seat 30 and coupling bolt 10. Moreover, this arrangement reduces the wear of both components 30, 10.

[0097] According to another embodiment, the retaining force between the inner latching bars 56 and the coupling bolt 10 can be specifically increased. To this end, the shaft 12 and coupling head 14 may be provided with a slot-shaped cross-section. The longitudinal axis of the slot-shaped cross-section is arranged parallel to the longitudinal axis L.sub.42 of the dome cross-section 42. Due to this flattened geometry of the coupling bolt 10, there is a linear contact and support between the coupling seat 30 and coupling bolt 10 instead of a point contact as similarly depicted in FIG. 5b. Then the coupling bolt 10″ may be used without the wings 18′.

[0098] As can be seen with reference to FIG. 4, the inner latching bars 56 restrict a movement of the coupling bolt 10 opposite the insertion direction R.sub.E. Transverse to the insertion direction R.sub.E, the seat space 40 provides a gap which permits the compensation movement in the direction of the arrows A. During these compensation movements, the inner bars 56 may guide the coupling bolt 10 when they engage in the peripheral recess 13 in the coupling bolt 10 between the coupling head 14 and the shaft 12.

[0099] Also, in at least some implementations, the coupling seat 30 does not have any inner latching bars that run parallel to the transverse axis Q.sub.36, Q.sub.42. This is because the inner latching bars 56 offer sufficient retention for the coupling bolt 10; 10′.

[0100] As already mentioned above, the coupling seat 30 may be produced by means of an injection molding method. In the context of this injection molding method, an injection mold is provided in a step S1 with the complementary features with respect to the above-described embodiments of the coupling seat 30. In step S2, the coupling seat 30 is injection molded into the provided injection mold. Then the coupling seat 30 is demolded from the injection mold in step S3.