This application claims priority from German Patent Application No. DE 102012003337.0, filed on Feb. 17, 2012, the disclosure of which is incorporated herein by reference.
The present invention relates to a fastening apparatus for fastening to a spherical stud, in particular a ball stud, having an inner sleeve, which can splay out in the radial direction and can be slid onto the stud, and having an outer sleeve, which can be slid over the inner sleeve in an axial direction into a fastening position, the outer sleeve being releasably fastenable to the inner sleeve in the fastening position by means of a latching device.
A fastening apparatus of this type is known from document DE 32 32 926 C2 and can be used to fasten component parts. The spherical stud can be fixed to one of the component parts. At least one further component part can be fixed to the first component part by means of the fastening of the fastening apparatus to the spherical stud.
In the known fastening apparatus described above, the inner sleeve is formed as a collet which is designed to engage, from behind, an end part of the stud, said end part being undercut in the direction of fitting. The outer sleeve is formed as a locking part which can be fitted onto the collet. At the front end parts of the locking part and of the collet, cooperating latching means are provided which are formed as circumferential latching ribs and latching grooves. In one variant, the latching means can be designed so as to be releasable. It is not possible to achieve high retaining forces in this variant. In a further variant, the latching means thus have flanks which are so steep that the latched connection to be achieved is unreleasable. In this case, high retaining forces can be achieved. However, fastening apparatuses in this variant can only be disassembled in a destructive manner.
On this basis, the object of the invention is to provide an improved fastening apparatus with which high retaining forces of a fastening arrangement formed therewith can be achieved and which can still be disassembled without destruction.
This object is achieved with the fastening apparatus described in the introduction in that the latching device has at least one latching tongue which engages, from behind, a latching shoulder in the fastening position, thus forming a latched connection which is secured against release, at least one tool access portion being provided on the outer sleeve and/or on the inner sleeve, a tool for releasing the latched connection being guidable through said tool access portion.
The latched connection is consequently formed by the cooperation between at least one latching tongue and a corresponding latching shoulder. Due to the steepness of their flanks, the latching tongue and/or the latching shoulder are formed in such a way that it is possible to form a latched connection secured against release. The latching tongue and/or the latching shoulder preferably do not extend over the entire circumference of the fastening apparatus. The latching tongue and/or the latching shoulder should preferably extend over an angular range of less than 90°, in particular less than 60°, preferably less than 45°.
The ability of the inner sleeve to splay out radially can preferably be implemented by introducing at least one axial slit into the inner sleeve, said axial slit preferably extending over at least 60% of the axial length of the inner sleeve.
The inner sleeve and the outer sleeve can be provided as separate component parts. Furthermore, it may be possible to pre-assemble the inner sleeve and the outer sleeve, for example a further latching recess being provided for preassembly, in which the latching tongue can engage.
The inner sleeve and outer sleeve are particularly preferably provided in one piece however, the inner sleeve and the outer sleeve being axially offset with respect to one another and being connected in an axially small region of overlap via a connecting portion which can be separated, in particular by applying an axial force between the inner sleeve and the outer sleeve.
It is advantageous if the fastening apparatus is formed in one part or integrally in the pre-assembled state.
High retaining forces can be achieved as a result of the latched connection, which is established in the fastening position between the latching tongue and the latching shoulder. It is still possible, via the tool access portion, to release the latched connection so as to disassemble the fastening apparatus, in particular to detach the outer sleeve from the inner sleeve, the inner sleeve and the outer sleeve not being damaged at all or substantially during this process.
For example, a screwdriver or a similar tool may be used as a tool in this instance and is guided through the tool access portion and bends the latching tongue away radially so as to release the latched connection.
The fastening apparatus preferably has two latching tongues which are diametrically opposed in the radial direction and two latching shoulders which are accordingly diametrically opposed. A tool for releasing the latched connection preferably has two tool tips which are preferably introduced at the same time into suitable tool access portions so as to simultaneously force the two latching tongues away and so as to simultaneously release the two latched connections formed thereby.
The fastening apparatus is preferably formed in such a way that the extent to which the inner sleeve can be splayed out in the radial direction is restricted when the outer sleeve is slid over the inner sleeve so as to thus establish a positive connection in the axial direction between the spherical stud and the inner sleeve. A positive connection in the axial direction between the inner sleeve and the outer sleeve is also established by the latched connection, and therefore high retaining forces can be achieved.
The inner sleeve and/or the outer sleeve are preferably formed of a plastics material and are preferably produced by an injection moulding method. In the case of a one-part fastening apparatus, the separable connecting portion between the outer sleeve and the inner sleeve may be formed by one or more thin webs between the inner sleeve and the outer sleeve.
The object is thus achieved completely.
According to a particularly preferred embodiment, the latching tongue is formed on the inner sleeve and/or the latching shoulder is formed on the outer sleeve.
In this case it is advantageous if, in a relaxed position, the latching tongue can extend beyond the outer circumference of the inner sleeve so that it is relatively easy to slide the outer sleeve over the inner sleeve and to thus press the latching tongue radially inwardly until it ultimately engages, from behind, a latching shoulder on the inner circumference of the outer sleeve. In this embodiment a tool access portion can also be formed in a relatively simple manner, in particular by a central opening in the outer sleeve.
According to a further preferred embodiment, the tool access portion has an axial recess on an inner circumference portion of the outer sleeve.
A tool can thus be guided through the axial recess and into the region of the latched connection.
According to a particularly preferred embodiment, the axial recess extends from one axial end of the outer sleeve (in particular an upper end) to the latching shoulder, which is preferably formed on the inner circumference of the outer sleeve.
The outer sleeve and the fastening apparatus formed therewith can thus be formed in a structurally simple manner.
According to a further preferred embodiment, the tool access portion has a radial recess on the outer circumference of the latching tongue.
It is thus possible, in particular in combination with an axial recess on the inner circumference of the outer sleeve, to guide a tool towards the latched connection. Owing to a recess of this type, the latching tongue can also be grasped securely so as to be pressed back and so as to thus release the latched connection.
According to a further embodiment, the latching tongue is formed on the outer sleeve and/or the latching shoulder is formed on the inner sleeve.
In particular, it is advantageous in this variant if the tool access portion has an axial recess in the inner sleeve.
The outer sleeve is preferably connected to a fastening portion. The fastening portion may have an annular collar portion extending radially outwardly with respect to the outer circumference of the outer sleeve in order to fix a planar second component part, such as a cladding part or a carpet portion, to a planar first component part, to which a spherical stud is fixed.
According to a further preferred embodiment, the fastening portion has a lower part and an upper part, which are interconnected by a hinge.
In this embodiment it is possible to provide receptacles for elongate objects between the lower part and the upper part. The outer sleeve is preferably a component part of the lower part. In this case, a recess may likewise be provided in the upper part so as to introduce therethrough a tool for releasing the latched connection.
It is generally preferred to introduce a tool into the outer sleeve via an axial central opening. If necessary, the central opening may be closed by a removable plug or the like.
According to a further embodiment, the tool access portion may also have a radial recess in the outer sleeve. This may be advantageous in terms of structure if the outer circumference of the outer sleeve is accessible, radially outwardly, in the fastening position.
According to a further, all in all preferred, embodiment, the inner sleeve and the outer sleeve can be interconnected in a non-rotational manner by means of an anti-twist protection device.
It can thus be ensured that the outer sleeve can only be slid axially onto the inner sleeve in one specific relative rotary position. In this one position, the latching tongue is oriented with the latching shoulder in the direction of rotation. In any case, the latched connection is consequently produced when the outer sleeve is slid on axially.
The anti-twist protection device is preferably formed in such a way that the inner sleeve and outer sleeve cannot, under any circumstance, be inserted into one another in a rotary position other than the predetermined rotary position, so as to thus prevent incorrect assembly.
The anti-twist protection device is preferably formed by a first anti-twist protection portion on the outer sleeve and by a second anti-twist portion on the inner sleeve, at least one of the two anti-twist protection portions extending in the axial direction.
A fastening arrangement can be formed by means of the fastening apparatus, a first and second component part being fixed to one another in said fastening arrangement and the spherical stud being fixed to one of the component parts.
A spherical stud is preferably to be understood to mean a rotationally symmetrical stud. This may be smooth at its outer circumference, or furrowed or the like. The spherical stud may be produced from a metal material so as to join the stud to a metal first component part, for example by means of stud welding. However, the stud may also be produced from a plastics material, in which case the first component part may likewise be produced from plastics material. Different joining methods, such as stud welding, bonding or thermowelding, are suitable for joining the stud to the first component part.
In the present case, a spherical stud is also understood to mean any type of stud which has a greater diameter in a centre region compared to a region adjacent to a joining face, with which the stud is joined to a first component part, in such a way that a radial undercut is provided between the centre region and the first component part. The spherical stud may be spherical or partly spherical in longitudinal section, but may also be shaped elliptically in longitudinal section or have an angular shape, such as a T-stud, which has a narrow shaft portion and a head portion of greater diameter which is grasped by a receptacle in the inner sleeve. In the latter case, the spherical receptacle may also be angular in longitudinal section.
The fastening apparatus is preferably used in the field of body construction of motor vehicles, for example to fasten cladding parts to bodywork portions or to fasten elongate second component parts to bodywork portions, the spherical stud preferably being joined to the bodywork portion.
It is understood that the features described above and those yet to be explained hereinafter can not only be used in the respective combinations disclosed, but can also be used in other combinations or alone, without departing from the scope of the present invention.
Exemplary embodiments of the invention are illustrated in the drawing and will be explained in greater detail in the description below. In the drawing:
A first embodiment of a fastening apparatus according to the invention is illustrated in
The fastening apparatus 10 has an inner sleeve 12 and an outer sleeve 14, which are arranged concentrically with respect to a longitudinal axis 16.
At its axial end, the inner sleeve 12 comprises a spherical receptacle 18 for a spherical member, such as a spherical stud, in particular a ball stud. The spherical receptacle 18 is formed in such a way that the inner circumference of the inner sleeve 12 is smaller in the region of this axial end 19 than in a (centre) portion 21 spaced axially therefrom. The inner sleeve 12 further has at least one, in the present case two, slits 20, which are diametrically opposed in the radial direction and which extend from the aforementioned axial end. The hollow semi-cylindrical portions 13 thus formed can be expanded resiliently with respect to one another in the radial direction owing to the longitudinal slits 20.
The inner sleeve 12 further comprises at least one, in the present case two, latching tongues 22, which are radially diametrically opposed and protrude radially in the relaxed state with respect to an outer circumference 24 of the inner sleeve 12. The latching tongues 22 can be deflected radially inwardly in such a way that the outer sleeve 14 can be slid over the inner sleeve 12. For this purpose, the latching tongues 22 may each comprise a bevel 26 on their radial outer side so as to facilitate the sliding-on of the outer sleeve 14.
At an axial end remote from the inner sleeve 12, the outer sleeve 14 has a fastening portion 30 for fastening a component part. In the present case, the fastening portion 30 is formed by an annular disc-like collar, which protrudes in the radial direction with respect to an outer circumference (not described in greater detail) of the outer sleeve 14.
The inner sleeve 12 and the outer sleeve 14 can be provided as separate component parts. However, the inner sleeve 12 and the outer sleeve 14 are preferably pre-assembled together so as to enable easier handling of the fastening apparatus 10. In the present case, the inner sleeve 12 and the outer sleeve 14 are interconnected by a separable connecting portion 32. The inner sleeve 12 and the outer sleeve 14 are preferably produced from plastics material in this instance, more specifically as a single element which is preferably produced in an injection moulding method. The connecting portion 32 can be formed by a circumferential, thin, separable web 33, or by a single individual web 33 or a plurality of individual webs 33 distributed over the circumference and interconnecting the inner sleeve 12 and the outer sleeve 14.
One or more radial recesses 34 can also be provided at the outer circumference 15 of the outer sleeve 14 and, for example, may perform the function of an anti-twist protection and/or may be used for attachment of a tool. For example, the radial recesses 34 may be used for positioning in an automatic assembly machine, in particular if the outer part 14 and the inner part 12 are produced separately and are pre-assembled together retroactively in an automated manner.
The protrusion forming the first anti-twist protection portion 36 can preferably also perform the function of the separable connection 32 and web 33. For example, the inner sleeve 12 and the outer sleeve 14 can be interconnected via one or two such protrusions, the protrusion being separated at its radially inward end when the outer sleeve 14 is slid onto the inner sleeve 12. The protrusion can thus perform the function of the first anti-twist protection portion 36 when the outer sleeve 14 is subsequently slid onto the inner sleeve 12. As a result of the anti-twist protection device thus established, the outer sleeve 14 can only be slid onto the inner sleeve 12 in one specific relative rotary position, thus ensuring that the respective latching tongues 22 are aligned with the latching shoulders 50.
The operating principle of the fastening apparatus 10 of
The fastening arrangement 40 comprises a first component part 42 which is formed, for example, as a planar component part such as a bodywork sheet. A spherical stud in the form of a ball stud 44 is joined to a surface of the first component part 42, for example by a stud welding method, by a bonding method or by another joining method.
A second component part 46 is placed on the same side of the first component part 42 and may likewise be formed as a planar component part, for example in the form of a cladding element or the like. The second component part 46 has a through bore 47 which is continuous and is preferably circular in cross-section. The second component part 46 is placed on the first component part 42 in such a way that the stud 44 lies within the bore 47, preferably concentrically therewith. A radially protruding portion (key) 48 may optionally be formed on the inner circumference of the recess 47 and, for example, may engage with the radial recess 34 so as to achieve anti-twist protection in a fastening position.
In
The outer sleeve 14 has an axially continuous central opening 52.
In order to establish the pre-assembled position A shown in
In addition, as discussed below, the latched connection 53 can also be released again so as to thus disassemble the fastening apparatus 10 with no damage at all, or no considerable damage.
In the present case, the outer sleeve 14 has at least one axial recess 54 on its inner circumference, it being possible to attach a tool via said recess so as to release the latched connection 53. The axial recess 54 extends from the outer axial end of the outer sleeve 14, down to the respective latching shoulder 50.
In addition or alternatively to this, the latching tongues 22 can be provided on their outer face with a radial recess 56, as shown in
As soon as the latched connection(s) 53 has/have been released, the outer sleeve 14 can be removed from the inner sleeve 12. The inner sleeve can then also be removed from the ball stud 44 since the inner sleeve 12 can splay out again in the region of the receptacle 18.
With the parts disassembled in this manner, assembly can take place again, for example once the second component part 46 has been replaced, the inner sleeve 12 first being placed over the ball stud 44 and the outer sleeve 14 then being positioned over the inner sleeve 12 and then slid thereon axially, as in the above-described method, too.
To release the latched connection 53 shown in
Further embodiments of fastening apparatuses are described in
In the case of the fastening apparatus 10′ shown in
The fastening apparatus 10″ shown in
To achieve the fastening position, the lower part 66 and the upper part 68 are opened via the hinge 70, and the lower part 66 is pressed onto the inner sleeve 12 by the outer sleeve 40 integrated in said lower part. The upper part 68 can then be folded down onto the lower part 66, one or more receptacles for elongate objects being formed between the lower part 66 and the upper part 68. In the present case, a first receptacle 72 is formed on one side of the longitudinal axis 16, and a second receptacle 74 is formed on the other side of the longitudinal axis. The upper part 68 can be locked to the lower part 66 by means of a catch 76 (not described in greater detail).
Although exemplary embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Number | Date | Country | Kind |
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102012003337.0 | Feb 2012 | DE | national |