LED attachment element

Abstract

The invention relates to an attachment element for electrically attaching an LED lighting device, the LED lighting device having a circuit board which is provided with a contact region for supplying power to the LEDs, the attachment element having a frame which is provided for lying on an arrangement surface of a support and for holding the circuit board on the arrangement surface, the frame is formed by an outer ring and an inner ring, the attachment element is provided with the inner ring, the inner ring is held in the outer ring and is used for covering the circuit board at least partially and holding the circuit board on the support perpendicularly to the arrangement surface, the attachment element is provided with the outer ring, and the outer ring is used for covering the circuit board at least partially and holding the circuit board on the support perpendicularly to the arrangement surface. The outer ring is provided for surrounding the circuit board and holding the circuit board on the support parallel to the arrangement surface, the attachment element has a latching lug, which is formed by the inner ring, and the attachment element has a latching spring, which is formed by the inner ring and which is arranged on the outer ring. The locking spring is arranged in the outer ring, overlaps the locking lug of the inner ring and exerts a tensile force on the inner ring in the direction of the arrangement surface, a spring receiving space is provided for the locking spring, the spring receiving space extends relative to the frame lying flat on the arrangement surface to a region below the arrangement surface.

Description

Technical Field

[0001] The present invention relates to an attachment element for electrically attaching an LED lighting device. - wherein the LED lighting device has a circuit board provided with contact areas for supplying power to the LED, the attachment element has a frame which is provided for lying on a placement surface of a support and for holding the circuit board on the placement surface, wherein the frame is formed by an outer ring and an inner ring, the attachment element has an inner ring, which is held within an outer ring and is provided to at least partially cover the printed circuit board and thus hold it perpendicular to the arrangement surface on the support, the attachment element has an outer ring which is provided to surround the printed circuit board and to hold the printed circuit board on the support parallel to the arrangement surface, - the attachment element has a latching lug, which is formed by the inner ring, The attachment element has a latching spring which is arranged in the outer ring, engages over a latching lug of the inner ring and exerts a tensile force on the inner ring in the direction of the arrangement surface. Background Art

[0002] For example, EP 2 083 489 A1 by the present applicant discloses an attachment element for electrically attaching an LED lighting device and simultaneously for mechanically securing it. The generally annular component has an integrated contact assembly that enables the attachment of external attachment conductors and transmits the thus-introduced power to contact areas of a circuit board equipped with an LED.

[0003] The annular component has a circuit board at the same time. For this reason, the component has a central recess that accommodates the circuit board.

[0004] The annular component is fixed to a support (usually to a heat sink or a lamp board) by means of suitable fastening means (eg screws, expansion anchors, etc.) and thus holds the printed circuit board between itself and the support.

[0005] In this way, the LED lighting device is mechanically fixed and electrically attached to the corresponding power supply.

[0006] Attachment elements of this type are widely used in the production of modern luminaires using LED lighting devices and have been further developed compared to the embodiments shown in the aforementioned documents.

[0007] In particular, the goal is to minimize the size of the contact assembly so that the attachment element is as flat as possible in terms of its height measured in the light emission direction. This prevents shading of the light emitted by the LED by the attachment element, which significantly improves the efficiency of the lighting device.

[0008] In addition, the optical device and the reflector mounted on the attachment element can be moved closer to the light exit plane of the LED. In this way, the efficiency of the reflector and the optical device can be significantly improved.

[0009] The applicant discloses a further development of such an attachment element, corresponding to the superordinate concept, under the document number DE 20 2023 105 716 U1. In this document, for reasons of improved logistics, the annular attachment element is divided into an inner ring and an outer ring. The outer ring serves to hold the circuit board in a direction parallel to the arrangement surface of the support. The inner ring is inserted into the outer ring and at least partially covers the circuit board. In this way, the inner ring locks the circuit board to the support in a direction perpendicular to the arrangement surface. In this embodiment, the attachment element also carries a contact assembly, which enables the circuit board to be electrically attached to an external attachment conductor.

[0010] For the mechanical fixing, electrical supply and safe operation of LED lighting devices, a series of detailed requirements need to be considered. The thickness of the circuit board - measured in the light emission direction or perpendicular to the layout surface - has significant fluctuations.

[0011] The circuit board needs to be pressed onto the support with a certain pressing force in order to ensure optimal heat dissipation. Only when the operating heat generated by the LED is sufficiently dissipated can the durability of the LED lighting device be guaranteed.

[0012] To optimize heat transfer from the circuit board to the support, various types of thermally conductive elements are introduced between the two. These range from thermally conductive paste to relatively thick thermal pads. Typically, the luminaire manufacturer selects the thermally conductive element that they consider suitable. The attachment element must also be able to compensate for the additional thermally conductive layer.

[0013] Finally, it is important to optimize the contact forces between the contact area of the circuit board and the contact assembly of the attachment element in the direction of minimizing the transfer resistance. In the two-part attachment element on which the present invention is based, the contact assembly comprises attachment contacts inserted into an outer ring, against which the attachment conductor rests. The inner ring carries the supply contacts, which rest on the contact area of the circuit board.

[0014] The attachment contacts and the supply contacts also have abutment surfaces against each other so that power can ultimately be fed in. In other words, even in the two-part attachment element according to the invention, it is necessary to ensure that the contact force between the attachment contacts and the supply contacts is optimized in the direction of the lowest possible transmission resistance. Summary of the Invention

[0015] The object of the present invention is therefore to provide a suitable latching spring arrangement for a two-part attachment element, which ensures the pressing force of the inner ring on the circuit board while taking into account the necessary tolerance compensation.

[0016] The object of the invention is achieved by an attachment element having the features described below, in particular the characteristic features described below, according to which a spring receiving space for a latching spring is present, which extends relative to the frame lying on the arrangement surface into an area below the arrangement surface.

[0017] In order to compensate for high tolerances in the thickness of the circuit board and any heat-conducting components that may be arranged between the circuit board and the support, the inner ring must be able to move a relatively large distance perpendicular to the support's mounting surface or in the light emission direction of the LED. At the same time, the latching spring must be able to exert a sufficient pressing force in the direction of the mounting surface at any position of the inner ring that is affected by tolerances.

[0018] To achieve this, a latching spring is required that can travel a relatively large spring travel and exert a sufficient contact pressure. The large spring travel requires space in the attachment element. The high spring force necessitates specific dimensions for the latching spring element. These requirements for the latching spring conflict with the technical need to achieve a design for the attachment element that is as flat as possible in order to prevent the emerging light from being obstructed by the attachment element.

[0019] The present invention provides for shifting the required installation space for the latching spring to be used into a region below the mounting plane of the support, or at least extending it into this region. This allows the thickness of the attachment element, measured in the light emission direction or perpendicular to the mounting plane of the support, to be kept at a reduced, essentially required thickness. Blocking of the emitted light by the attachment element is reliably avoided or significantly reduced. Nevertheless, sufficient installation space remains for a latching spring element that, due to the spring force to be applied and, in particular, the required spring travel, requires a sufficiently large spring accommodation space.

[0020] In a specific embodiment, the present invention provides that the spring receiving space is formed by a dome that projects from the underside of the outer ring and is oriented, in particular, counter to the light emission direction. The spring element can be arranged in this dome, thereby providing sufficient movement space for the required spring travel, especially in the case of a spring element with a pivot axis oriented parallel to the arrangement surface, as shown in this embodiment.

[0021] In another alternative embodiment, the spring receiving space is formed by a cavity in the support. Thus, for example, a corresponding cavity or recess can be introduced into the heat sink—either as a blind hole or as a continuous bore. This provides the inserted latching spring with sufficient space and sufficient room to generate a large spring travel.

[0022] In a particularly preferred embodiment, the dome of the spring receiving space of the outer ring is inserted into the cavity of the support. In this way, the dome formed by the outer ring is well protected in case of mechanical damage by the material of the support, especially the surroundings of the heat sink.

[0023] In order to be able to absorb high spring forces, especially in the case of an inner ring made of plastic, a sufficient material thickness is required in the area interacting with the latching spring. Specifically, the latching projection needs to be sufficiently thick so that it does not undergo plastic deformation under the influence of the spring force of the latching spring.

[0024] However, this means that space has to be created for a correspondingly thick material carrier, which—as already mentioned—runs counter to the requirement for a particularly flat attachment element.

[0025] Therefore, supplementally, the present invention proposes that inner ring structures spring support leg, and this spring support leg carries the latch projection.At this, especially setting, the spring support leg stretches into the spring receiving space and especially abuts on the wall of the limit spring receiving frame.

[0026] The invention recognizes that the spring receiving space already creates space for providing a latching projection dimensioned sufficiently to absorb the spring force without this having a negative impact on the dimensions of the part of the attachment element located above the arrangement surface.

[0027] Furthermore, the present invention recognizes that the latching projection can be kept relatively small in size if the latching projection rests against a wall delimiting the spring space and is supported there. Thus, the wall delimiting the dome or the cavity serves to support the forces acting on the latching projection. Thus, the spring support leg forming the latching projection can be relatively small, since the spring force is also absorbed by the corresponding wall.

[0028] In a particularly preferred embodiment, the spring-loaded legs rest against the wall forming the dome, which in turn rests against the wall delimiting the cavity. Since the support is usually made of metal, in particular aluminum, the dome and the spring-loaded legs, made of the plastic material of the inner and outer rings, are supported very well in a load-dissipating manner on a more stable material.

[0029] In addition, the present invention recognizes that the latching spring that is used to fix the inner ring is also suitable for outer ring being fixed on the support. In this way, the latching spring of outer ring obtains dual purpose.

[0030] In particular, when the support is a heat sink, when providing the boreholes for the cavities, undercuts are usually produced in the region of the cooling ribs, into which the latching springs can engage in order to fasten the outer ring to the support.

[0031] Alternatively, it is conceivable to design the dome of the outer ring in the manner of an expansion anchor. To this end, the dome can be designed perpendicular to the arrangement surface, for example, in the form of a slot. The dome wall is offset by the expansion element and can engage with the support in a friction-locking and / or form-locking manner. Undercuts in the area of the cooling ribs, for example, produced by inserting drilled holes into the heat sink, are also suitable for this purpose. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The invention will now be explained in more detail with reference to two exemplary embodiments, from which further advantages and features emerge. The accompanying drawings show: Figure 1 In the exploded schematic view, the attachment element according to the invention is shown supplemented by an LED lighting device and a holder. Figure 2 Shown in assembled form Figure 1 The structural group, Figure 3 Show the basis Figure 2 A top view of the structural group, Figure 4 Show the basis of the structure group Figure 3 The cross-sectional view of the section line AA in Figure 5 yes Figure 3 A sectional view of the assembled structural group according to section line AA, Figure 6 An exploded schematic diagram showing an alternative embodiment of the present invention, Figure 7 Show the basis Figure 6 A top view of an embodiment of Figure 8 Shown as Figure 6 Shown is a sectional view according to section line BB. DETAILED DESCRIPTION

[0033] In the figures, the assembly is generally designated by the reference numeral 100 using the attachment element according to the invention.

[0034] In addition to the support 11 in the form of a heat sink 12 , the assembly 100 initially comprises a printed circuit board 13 . The printed circuit board 13 is provided with LEDs 14 and, among other things, carries contact pads 15 .

[0035] The support 11 has a mounting surface 16 oriented relative to the printed circuit board 13 and having threaded holes 17 and cavities 18 .

[0036] The attachment element comprises an outer ring 19 and an inner ring 20 and also has a latching spring 21. In the exemplary embodiment, the contact assembly provided for supplying power to the circuit board 13 is not shown, since it plays only a secondary role in the core of the invention.

[0037] The screw bolts 22 are passed through the fastening bores 23 of the outer ring 19 and are inserted into the threaded bores 17 of the heat sink in order to fix the outer ring 19 to the heat sink 12 .

[0038] The outer ring 19 forms a receiving frame 24 into which the printed circuit board 13 can be inserted.

[0039] The dome 25 projects on the underside of the outer ring 19 facing the arrangement plane 16. The receiving space 26 allows the inner ring 20 to be inserted into the outer ring 19. The vertical axis V, which is parallel to the light emission direction or perpendicular to the arrangement plane, forms the central axis of the attachment element 10.

[0040] Spring support legs 27 project from the inner ring 20 on its lower side facing the arrangement surface 16 . In addition, the inner ring 20 forms a central light passage opening 28 , which surrounds the LED 14 .

[0041] Figure 2 Shown in assembled form Figure 1 Here, it can already be seen in part that Figure 1 The outer ring 20 rests with its lower side facing the arrangement surface 16 on the arrangement surface 16 of the heat sink 12. The screws 22 are inserted into the fastening bores 23 and engage with their threaded shanks in the threaded bores 17 of the heat sink 12, which are not visible here because they are covered by the outer ring 19. In this way, the outer ring 19 is securely attached to the heat sink 12 or the support 11.

[0042] It is conceivable that the dome 25 projecting from the underside of the outer ring 19 is inserted into the cavity 18 of the heat sink 12 , so that the outer ring 19 can lie flat on the arrangement surface 16 .

[0043] The latching springs 21 are inserted into the domes 25 respectively associated therewith, wherein the spring support legs 27 are also immersed in the respectively associated domes 25. In this way, the inner ring 20 can be located in the receiving spaces 26 (not shown here) of the outer ring 19 and surround the LEDs 14 with its light passage openings 28 (not shown here).

[0044] Figure 3 Show the basis Figure 2 The top view of the structure group 100 is particularly used to illustrate the structure of the structure group 100 according to the following description. Figure 4 and 5 The situation of the cross section of the section line AA.

[0045] Figure 4 and 5 A cross-sectional view of the structural group 100 is shown, wherein Figure 4 is an exploded view of the section, Figure 5 is a cross-sectional view of the structural group 100 in the assembled state.

[0046] according to Figure 4 The sectional view first shows the inner ring 20. Each spring support leg 27 forms a latching lug 29 that points radially outward relative to the light emission direction L or the vertical axis V. Each latching lug 29 has a latching surface 30, which points toward the upper side facing away from the support 11, and a spreading surface 31, which points toward the support 11. Starting from a latching lug vertex 32, the latching surface 30 rises as an inclined surface in the direction of the vertical axis V. This latching lug vertex also defines the maximum radial outward extension of the latching lug 29. The spreading surface 31, on the other hand, is formed as an inclined surface on the spring support leg 27 that descends in the direction of the vertical axis V.

[0047] Figure 4 The latching springs 21 are also shown. These latching springs primarily comprise spring legs 33, for which latching legs 34 are provided for anchoring in the outer ring 19, in particular in the dome 25 thereof. In a specific embodiment, the latching legs 34 point radially outward and toward the top side of the attachment element 10, which faces away from the support 11. However, this is not absolutely necessary for the function of the latching legs 34. Furthermore, in this exemplary embodiment, the latching legs 34 also project from the lower ends of the spring legs 33, which face the heat sink 12.

[0048] The spring legs 33 carry a latching contour, designated overall by reference numeral 35, on their ends facing the top of the attachment element 10. This latching contour points radially inwards in the direction of the inner ring 20. Starting from a latching contour apex 36, a retaining leg 37 descends obliquely in the direction of the heat sink 12 and merges into the spring legs 33. Starting from the latching contour apex 36, a spreading leg 38 extends radially outwards in the direction of the top of the attachment element 10 and also forms the free upper end of the latching spring 21.

[0049] Figure 4 It also allows the dome 25 of the outer ring 19 to be viewed in detail.

[0050] Firstly, the dome 25 has, on its upper side facing the attachment element 10, an insertion opening 39 which enables access into a dome interior 40. The dome interior 40 can be divided into different functional areas as described below.

[0051] Firstly, the dome interior space 40 provides a spring support leg receptacle 41 into which the spring support leg 27 is inserted when the attachment element 10 is assembled. The spring support leg receptacle 41 is arranged radially inwardly in the dome interior space 40.

[0052] The latching leg receptacle 42 is located radially outward in the dome interior 40. In addition, the latching leg receptacle also forms a latching leg seat 43. The free end of the latching leg 34 is supported on the latching leg seat 43 for anchoring the latching spring 21 in the dome 25. The arrangement of the latching leg 34 in the latching leg receptacle 42 (including the anchoring of the latching leg 34 in the latching leg seat 43) can be Figure 5 Seen in.

[0053] A spring leg channel 44 is formed in the dome 25 between the spring leg receptacle 41 and the latching leg receptacle 42. The spring leg channel 44 is delimited relative to the spring leg receptacle 41 by a supporting wall 45, which prevents the spring leg 33 from moving excessively radially inward in the direction of the spring leg. The spring leg channel 44 is delimited in the direction of the latching leg receptacle 42 by a guide pin 46, which holds the lower end of the spring leg 33 in the spring leg channel 44 in a positionally stable manner and prevents the spring leg 33 from jumping into the latching leg receptacle 42.

[0054] The supporting wall 45 and the guide pin 46 are oriented perpendicularly to the arrangement surface of the support 11 or parallel to the vertical axis V, so that the functional spaces (i.e. the spring support leg receptacle 41, the latching leg receptacle 42 and the spring support leg shaft 44) are vertically separated from each other and can be accessed via the insertion opening 39 of the arch 25.

[0055] From the pair Figure 4 and 5 The overview of FIG. 1 shows how the assembly 100 , in particular the attachment elements 10 , are assembled.

[0056] First, the latching spring 21 is pushed into the respectively assigned dome 25 counter to the light emission direction L, i.e., from the top side of the attachment element 10. Here, the spring legs 33 enter the spring leg wells 44. Simultaneously, the latching legs 34 are retained in the latching leg seats 43 of the latching leg receptacles 42. In this way, the latching spring 21 is latched in the dome 25. The latching contour 35 of the latching spring 21 extends radially inward in the direction of the vertical axis V into the spring leg receptacles 41.

[0057] The outer ring 19 is now placed onto the heat sink 12 , wherein the dome 25 is pushed into the cavity 18 . In this way, the underside of the outer ring 19 facing the heat sink 12 lies flat on the arrangement surface 16 of the heat sink 12 .

[0058] Now, to assemble the structural unit 100, the printed circuit board 13 (i.e., the LED luminous element) is inserted into the insertion receiving frame 24 formed by the outer ring 19, so that the bottom side of the printed circuit board 13 also lies flat on the arrangement surface 16 of the heat sink 12. If necessary, a heat conducting element is also arranged between the printed circuit board 13 and the heat sink 12—not shown in the drawings.

[0059] The circuit board 13 is now securely held within the outer ring 19 against any movement horizontally or parallel to the arrangement surface.

[0060] The inner ring 20 is now placed onto the outer ring 19 against the light emission direction L. The spring support legs 27 are inserted into the respectively assigned domes 25 and there into the corresponding spring support leg receptacles 41. The expansion surfaces 31 of the respective latching tabs 29 come into contact with the respectively assigned expansion legs 38 of the latching springs 21. The resulting beveled surfaces 31 / 38 cause the latching contour 35 to move radially outward. This movement reaches its maximum when the latching contour apex 36 lies on the latching tab apex 32. Subsequently, as the insertion movement continues against the light emission direction L, the retaining legs 37 engage with the corresponding locking surfaces 30 of the latching tabs 29. The latching contour 35 is then displaced radially inward in a spring-returning manner. The beveled surfaces 31 / 38 between the retaining legs 37 and the locking surfaces 30 exert a force component on the inner ring 20 directed in the direction of the arrangement surface 16. As a result, the inner ring 20 is tensioned against the inserted circuit board 13 and ensures sufficient contact pressure of the circuit board 13 on the heat sink 12 to promote optimal heat dissipation. In the same way—not shown in detail here—the aforementioned force component of the inner ring 20 tensioning in the direction of the arrangement surface 16 also promotes the correct contact of the contact assembly on the contact area 15 of the circuit board 13 to achieve the correct electrical transition value.

[0061] Due to the dome 25 extending into the area below the arrangement surface 16, a sufficiently large space is created to realize a spring element in the form of a locking spring 21 extending longitudinally in the light emission direction L or parallel to the vertical axis V, which provides a sufficiently large spring path via the longitudinal extension of the spring legs 33 in the spring leg well 44 for fixing the inner ring 20 in the outer ring 19.

[0062] Figure 6 An exploded view showing an alternative embodiment of the present invention. Figure 1 The same applies to the present schematic diagram. This also shows a structural assembly 100 having an attachment element 10, which holds an LED luminous means (consisting of a circuit board 13 with contact areas 15 and LEDs 14) on a support 11 in the form of a heat sink 12. The attachment element 10 is divided into an outer ring 19 and an inner ring 20, wherein the outer ring 19 carries a latching spring 21 for securing the inner ring 20.

[0063] The contents concerning the first embodiment also apply to the second embodiment. However, the two embodiments differ from each other in the fastening of the attachment element 10 to the cooling body 12. Figure 6As shown, the latching spring 21 has an additional component in the form of a spring-returning securing pin 47, which is arranged as an additional latching means on the latching spring 21. This securing pin serves—as will be described below—to fasten the outer ring 19 to the heat sink 12, so that the screw bolt 22 known from the first embodiment can be omitted.

[0064] Figure 7 A second embodiment of the invention is shown in assembled form. Figure 7 In particular, it is used to illustrate the position of the section line BB, Figure 8 It is a cross-sectional view related to it.

[0065] Figure 8 First, the heat sink 12 is shown with the cavity 18 known from the first embodiment, which extends as a continuous borehole from the upper side of the heat sink 12, on which the attachment element 10 is provided, to the lower side of the heat sink. The cavity 18 has a step 48 that narrows the cavity diameter and helps to fix the outer ring 19 of the attachment element 10. The latching spring 21 is anchored in the outer ring 19. Due to the sectional position, the latching legs 34 of the latching spring 21 can be seen, which are inserted into the latching leg receptacles 42. Figure 8 It can also be seen how, in the second embodiment, the securing pin 47, which is additionally arranged on the latching spring 21, hooks back onto the step 48 in the manner of a latching element and thus holds the latching spring 21 in the cavity 18. By virtue of the connection between the latching spring 21 and the outer ring 19, the outer ring 19 is thus firmly anchored to the heat sink 12, and the outer ring 19 in turn holds the inner ring 20 (not visible here), so that the attachment element 10 is arranged on the heat sink 12 via the latching spring 21.

[0066] An essential advantage of the present invention is that additional screws 22 for fastening the attachment element 10 to the heat sink 12 can be omitted.

[0067] It is mentioned in the claims, but not shown separately, that the dome 25 can also be designed as an expansion anchor. By means of a slot in the latching dome 25, which is oriented perpendicular to the arrangement surface 16, and an expansion element that can be introduced into the latching dome 25, the latching dome 25 can be expanded circumferentially so that it is inserted into the cavity 18 of the heat sink 12 with a friction fit or a form fit. The latching spring 21 can serve as the expansion element. Reference Signs List

[0068] 10 Attachment elements 11 Support 12 cooling body 13 Circuit Board 14 LED 15 contact area 16 Layout Surface 17 Threaded holes 18 Cavity 19 Outer Ring 20 Inner Ring 21 Lock spring 22 Tighten the bolts 23 Fastening drilling 24 Container frame 25 Vault 26 Accommodation Space 27 Spring support legs 28 light-through openings 29 Locking lug 30 Locking surface 31 Open face 32 Locking lug apex 33 Spring legs 34 locking legs 35 Lock profile 36 Locking contour vertices 37 Keep Legs 38 Spread your legs 39 Insert opening 40 Vault interior space 41 Spring support leg receiving portion 42 Locking leg receiving portion 43 Locking Leg Base 44 Spring Leg Hoistway 45 Support wall 46 guide pin 47 fixing pin 48 steps V axis L Light emission direction 100 Structure Group

Claims

1. An attachment element (10) for electrically attaching an LED lighting device, -in, The LED lighting device has a circuit board (13), which is provided with a contact area (15) for supplying power to the LED (14). The attachment element has a frame (24) which is provided for lying on the arrangement surface (16) of the support (11) and for holding the circuit board (13) on the arrangement surface (16), wherein the frame is formed by an outer ring (19) and an inner ring (20), The attachment element has an inner ring (20) which is held within the outer ring (19) and is provided for at least partially covering the circuit board (13) and thus holding the circuit board (13) on the support (11) perpendicularly to the arrangement surface (16), The attachment element has an outer ring (19) which is provided for surrounding the circuit board (13) and for holding the circuit board (13) on the support (11) parallel to the arrangement surface (16), - the attachment element has a latching lug (29) which is formed by the inner ring (20), The attachment element has a latching spring (21) which is arranged in the outer ring (19), engages over a latching lug (29) of the inner ring (20) and exerts a tensile force on the inner ring (20) in the direction of the arrangement surface (16), It is characterized by: A spring receiving space for the latching spring (21) is provided, which extends relative to a frame (24) lying on the arrangement surface (16) into a region below the arrangement surface (16).

2. The attachment element (10) according to claim 1, characterized in that The spring receiving space is formed by a dome (25) which projects from the underside of the outer ring (19).

3. The attachment element (10) according to claim 1, characterized in that The spring receiving space is formed by a cavity (18) in the support (11).

4. Attachment element (10) according to claims 2 and 3, characterized in that The dome (25) is inserted into the cavity (18).

5. The attachment element (10) according to claim 1, characterized in that The inner ring (20) forms a spring-loaded support leg (27) which carries a latching lug.

6. Attachment element (10) according to claim 5, characterized in that The spring support leg (27) projects into the spring receiving space and in particular rests against a wall delimiting the spring receiving frame.

7. Attachment element (10) according to claims 3, 5 and 6, characterized in that The spring support leg (27) is supported on a wall section of the support (11) that delimits the cavity (18).

8. Attachment element (10) according to claims 4, 5 and 6, characterized in that The spring support legs (27) are supported on domes (25) extending from the outer ring (19).

9. The attachment element (10) according to claim 2, characterized in that The latching spring (21) is held in the dome (25) in a form-fitting manner.

10. The attachment element (10) according to any one of the preceding claims, characterized in that A latching spring (21) arranged in the outer ring (19) not only fixes the inner ring (20) to the outer ring (19), but also fixes the outer ring (19) to the support (11).

11. The attachment element (10) according to claim 4, characterized in that The dome (25) is designed in the manner of an expansion anchor in order to hold the outer ring (19) on the support (11) in a form-fitting or friction-fitting manner.

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