EP3169179B2 - Seat belt buckle - Google Patents

Description

The invention relates to a seat belt buckle.

A seat belt buckle is part of a safety device in a vehicle and is firmly connected to the vehicle body. A tongue can be inserted into the belt buckle, on which a belt strap is provided which, when the tongue is inserted, partially surrounds a vehicle occupant in order to fix the occupant to the vehicle seat in the event of a strong deceleration of the vehicle.

Belt buckles with lighting devices are generally known from the prior art, with the lighting serving to identify a receiving area for a tongue so that the vehicle occupant can find the belt buckle more quickly. Finding the seatbelt buckle quickly increases the rate of buckling because the vehicle occupant does not have to look for the seatbelt buckle, which can reduce motivation to buckle up. The lighting devices should ensure reliable and permanent lighting of the recording area.

The belt buckles known from the prior art usually have a belt buckle housing, which is usually produced by a welding process in which two housing halves are materially connected to one another. Due to this cohesive connection, the lighting device can only be replaced with considerable effort, which is perceived as disadvantageous. Furthermore, the installation space within the belt buckle is limited, which is why a very compact design of the lighting device is necessary. In addition, the recording area should be illuminated over a large area and with high light intensity so that the vehicle occupant can find the recording area even if the seat belt buckle is in an unfavorable position. Previous belt buckles do not meet these requirements to the fullest satisfaction. A belt buckle according to the preamble of claim 1 is from the document US 2012/089302 A1 known.

The object of the invention is to provide a belt buckle that enables the best possible and lasting illumination of the receiving area of the tongue while requiring minimal space and provides an illuminated tongue insertion opening. Another object of the invention is to provide a belt buckle that is simple and inexpensive to manufacture and also allows individual adjustments of the belt buckle, for example according to customer requirements for different vehicle types.

According to the invention, this is achieved with a belt buckle with a housing and a lighting device present in the area of a tongue insertion opening, the lighting device comprising a lamp and a light guide with a light exit area and the light guide having an annular section which at least largely surrounds the tongue insertion opening. The provision of an annular section on the light guide allows the tongue insertion opening to be illuminated in a targeted manner at any point along its circumference and preferably over its entire circumference and thus to produce a clear, valuable identification of the tongue insertion opening. The lighting takes place in an area that, on the one hand, is clearly visible to the vehicle occupant when inserting the tongue and, on the other hand, is positioned in such a way that the use of any design elements in the area of the body of the housing is possible.

The housing, also referred to below as a belt buckle housing, can, for example, have a peripheral edge which surrounds a receiving area for a tongue, as well as a lighting device which has a light guide and a light source, the light guide having a light exit area in the form of a coupling surface which is located on the Edge of the belt buckle housing is provided, which forms the light exit area. The edge of the belt buckle housing represents the section of the belt buckle housing that is directly in the vehicle occupant's field of vision when the belt buckle assumes its typical position in the vehicle. Since the decoupling surface of the light guide is provided on this edge, it is ensured that the receiving area, which forms the tongue insertion opening, is so well illuminated that the vehicle occupant can find it even when the belt buckle is in unfavorable positions. The light emitted by the lamp is guided to the output surface via the light guide, which enables a compact arrangement of the lighting device. This is because the lamp itself can be arranged at a position within the belt buckle where more space is available than directly at the edge. The light source can in particular be an LED, which is particularly compact.

Preferably, the light exit region is formed circumferentially on an axial end face of the annular section of the light guide, which enables illumination encircling the tongue insertion opening. The light exit area can, for example, be approximately 1 mm wide in the radial direction (radial to the insertion direction), which results in subtle, but still clearly perceptible lighting in the area of the tongue insertion opening without increasing the volume of the belt buckle.

The light guide preferably consists of a transparent plastic, in particular a polycarbonate (PC).

In order to achieve uniform illumination, the light guide can have a structured surface on an outer surface facing away from the light exit area. This structured surface is then designed so that it is not flat, but rather one Has a plurality of small structures arranged next to one another, which are designed and aligned so that they reflect the light back into the interior of the annular region of the light guide and thus bring about a homogeneous distribution of the light within the light guide. The structured surface is preferably provided on an end face of the annular section of the light guide opposite the light exit region.

The structured surface has, for example, a plurality of prisms arranged next to one another, each of which in particular has a trapezoidal or triangular cross-section and forms a type of sawtooth structure along the rear end face of the light guide. In this way, very uniform illumination of the entire annular section can be achieved even when the light is coupled into the light guide at specific points.

To couple the light from the lamp into the light guide, the light guide can have an extension or a coupling element that projects axially from the annular section of the light guide. The extension preferably extends to an area in which the lamp of the lighting device can be easily placed and directs the light from the lamp to the annular section and to the light exit area.

In order to further improve the distribution of the light in the annular section of the light guide, a recess can be provided in the annular section in the light guide, for example in the area of the transition of the extension into the annular section. This recess is shaped in such a way that the coupled-in light is distributed evenly in the annular section. The coupled light is reflected into the annular section in the circumferential direction, in particular at edges of the recess lying obliquely to the axial direction, and is thus evenly distributed in the annular section. For example, the recess is a breakthrough in the annular section, which has an approximately triangular shape, with the tip directed towards the extension. Instead of a triangular shape, other shapes can also be used, which suitably have reflection surfaces that run obliquely to the axial direction and can thus cause a reflection into the annular section.

According to the invention, the annular section of the light guide is arranged radially within an at least largely circumferentially closed front panel of the housing, which is to be viewed as a further housing part, the front panel framing the insertion opening. The front panel shields the light guide radially outwards, and can extend over the entire axial length of the light guide and beyond. The outer surface of the front panel can be designed in any way and can be used as a customer-specific design element.

An even more uniform light distribution along the light exit area as well as the possibility of an individual design of the light exit area of the belt buckle for different vehicle types is achieved according to the invention in that the front panel has an annular, at least partially transparent diffuser, which adjoins the light exit area of the light guide axially on the front side. This diffuser can also darken areas of the light exit area or can change the color of the emerging light.

An air gap is arranged between the diffuser and the light guide to reduce total reflections and to ensure a high level of light emission through the diffuser. The height of the air gap between the diffuser and the light guide is less than 0.5 mm, preferably in the range from 0.15 mm to 0.35 mm.

The outside of the diffuser facing away from the light guide has a very fine-grained structure, which further improves the homogeneity of the light emission. The diffuser is roughened with a very low graininess.

With the exception of the diffuser, the front panel is preferably opaque, so that light only emerges through the diffuser.

The front panel and diffuser can be manufactured in one piece using a two-component injection molding process, for example from acrylonitrile butadiene styrene (ABS) and polycarbonate (PC).

However, the front panel and light guide are preferably separate components, although one-piece production would also be conceivable. The front panel can be attached to the light guide during production of the belt buckle, and the light guide and front panel can be welded together for final attachment, for example by ultrasonic or laser welding.

The housing of the belt buckle preferably has a first shell part which has an annular, circumferential projection which is arranged radially within the light guide. This circumferential projection is arranged at an end of the first shell part on the insertion opening side, and the annular section of the light guide is designed so that it can be plugged onto the projection of the first shell part. The ring-shaped, circumferential projection of the first shell part shields the light guide radially inwards from the tongue insertion opening, so that no unwanted light emerges there.

The light guide can be welded to the annular projection of the first shell part or attached to it in another suitable way.

The lighting device preferably comprises an electronic control module in which the lamp and electronics are arranged. In particular, the electronic control module is attached to the inside of the first shell part of the housing. For example, one or more LEDs are used as lighting devices. A way to change the color of the This makes it easy to provide a light source. The color selection can be stored in a memory in the electronic control module and thus adapted to different vehicle types.

The electrical supply line can be integrated into an electrical supply line of a seat occupancy detection switch in the belt buckle in order to reduce the number of separate electrical cables. Excessive strain on the supply line can be prevented by strain relief on the first shell part of the housing

It is possible to pre-assemble the electronic control module on the first shell part, which reduces the number of individual components of the belt buckle during final assembly. Of course, the electronic control module can also be placed on another part of the housing.

The electrical control module is preferably designed as a LIN module (Local Interconnect Network Bus) and can be connected to general vehicle electronics.

In a preferred embodiment, the housing of the belt buckle consists only of the first shell part, the front panel and a second shell part, so that the belt buckle can be installed quickly and easily.

According to one aspect, the light guide is connected to the belt buckle housing, in particular latched or permanently attached to it. This enables a particularly compact design of the belt buckle housing, since the light guide does not have to be attached to the belt buckle housing using fasteners. This also simplifies the manufacture of the belt buckle. A snap connection also makes it possible to change the light guide. The light guide can in particular be injection molded with the associated housing part in a 2-component injection molding process, so that no assembly is necessary. The light guide can therefore be molded onto the belt buckle housing.

Furthermore, the decoupling surface can be designed to be circumferential. The decoupling surface provided on the edge can therefore surround the insertion opening forming the receiving area in a ring, so that the vehicle occupant can quickly see where the receiving area is located, namely in the area enclosed by the decoupling surface. This increases the rate of wearing a seat belt because the vehicle occupant does not have to spend a long time searching for the recording area.

A further aspect provides that the light guide has a coupling element which is coupled to the lamp and is in particular designed to taper in a wedge shape. The coupling element of the light guide ensures that the light emitted by the lamp is completely coupled into the light guide. This increases the luminosity in the area of the coupling surface. Due to the wedge shape of the coupling element, a space-saving light guide is nevertheless created which only has a correspondingly large cross section in the coupling area.

In particular, the belt buckle housing is composed of several shell parts, with the light guide being assigned to a housing section on which the edge is formed. The multi-part design of the belt buckle housing makes it possible to open the belt buckle housing quickly and easily, which means that the lighting device can be changed quickly and easily. Furthermore, it is ensured that the decoupling surface is provided on the edge of the belt buckle housing, since the light guide is arranged on the housing section of the multi-part belt buckle housing.

Another aspect provides that the light guide is essentially embedded in the housing section. This means that the light guide is essentially surrounded by housing material, which means that no additional light decoupling surfaces are created, as would be the case if the light guide were only arranged on the inside of the belt buckle housing. The light guide is therefore essentially completely enclosed by the housing section. Only the coupling-out and coupling-in areas are not enclosed by the housing material of the housing section in which the light guide is embedded.

In particular, the belt buckle housing can be designed in two parts and comprise two shell parts or housing shells, with the housing section being provided on a first housing shell. The two-part design makes it possible to open the belt buckle housing quickly and easily, as well as simple production, since a first housing shell has the essential parts of the belt buckle, for example the lighting device, whereas the second housing shell only serves to close the belt buckle housing. The second housing shell therefore represents a type of cover element. The second housing shell can be a standardized housing shell.

Alternatively, the belt buckle housing can be designed in three parts and include two shell parts and a, in particular insertable, housing part, corresponding to the front panel described above, on which the housing section is provided. The two shell parts can be conventional, standardized belt buckle shells that can be coupled together to form a type of base body of the housing lock. The housing part, which can be inserted or plugged into the base body, has the housing section on which the light guide is provided. The housing part is therefore ring-shaped and provides the edge of the belt buckle housing, which surrounds the receiving area for the tongue.

In particular, the light guide can have a connection structure with which the housing part forming the front panel can be connected to the other shell parts. The housing part is connected via the light guide firmly coupled to the two shell parts, thereby providing a complete belt buckle housing.

A belt buckle described above can be produced in such a way that the light guide and at least one housing section are injection molded at the same time, in particular in a multi-component injection molding process. This makes it possible to produce the belt buckle particularly quickly and easily, since the belt buckle housing is at least partially formed directly with the light guide. The light guide therefore no longer needs to be subsequently coupled to the belt buckle housing. This also ensures that the orientation of the light guide within the belt buckle housing is correct, which guarantees homogeneous illumination of the decoupling surface. The remaining parts of the belt buckle can be designed as a simple and inexpensive injection molded part that only has one material component.

In particular, the light guide and the at least one housing section are injection molded in such a way that the light guide is essentially embedded in the housing section. On the one hand, the light guide is protected by the housing material surrounding it, and on the other hand, it is ensured that the light guide only has the decoupling surface provided at the edge. As a result, the light intensity on the output surface is correspondingly high, since no scattering losses or the like occur.

• Figur 1 eine schematische perspektivische Darstellung eines erfindungsgemäßen Gurtschlosses;
• Figur 2 das Gurtschloss aus Figur 1 in einer Seitenansicht;
• Figur 3 das Gurtschloss aus Figur 1 in einer Draufsicht;
• Figur 4 ein erstes Schalenteil des Gehäuses des Gurtschlosses aus Figur 1;
• Figur 5 ein elektronisches Steuermodul der Beleuchtungseinrichtung des Gurtschlosses aus Figur 1;
• Figur 6 eine Darstellung des elektronischen Steuermoduls, montiert im ersten Schalenteil;
• Figur 7 eine perspektivische Darstellung eines Lichtleiters des erfindungsgemäßen Gurtschlosses aus Figur 1;
• Figuren 8 und 9 Details des Lichtleiters aus Figur 7;
• Figur 10 eine Variante des Lichtleiters aus Figur 7;
• Figur 11 eine Frontblende des Gurtschlosses aus Figur 1,
• Figur 12 ein erstes Schalenteil mit montiertem Lichtleiter und montierter Frontblende für das Gurtschloss aus Figur 1;
• Figur 13 die Innenseite eines zweiten Schalenteils des Gehäuses des Gurtschlosses aus Figur 1;
• Figur 14 eine schematische Schnittansicht des erfindungsgemäßen Gurtschlosses aus Figur 1;
• Figur 15 eine Perspektivansicht eines erfindungsgemäßen Gurtschlosses gemäß einer weiteren Ausführungsform,
• Figur 16 eine weitere Perspektivansicht des Gurtschlosses aus Figur 1,
• Figur 17 eine Perspektivansicht eines Gehäuseteils des Gurtschlosses aus den Figuren 15 und 16,
• Figur 18 eine weitere Perspektivansicht des Gehäuseteils aus Figur 17,
• Figur 19 eine weitere Perspektivansicht des Gehäuseteils aus Figur 17,
• Figur 20 eine weitere Perspektivansicht des Gehäuseteils aus Figur 17,
• Figur 21 eine weitere Perspektivansicht des Gehäuseteils aus Figur 17,
• Figur 22 eine Perspektivansicht einer Gehäuseschale eines Gurtschlosses gemäß einer weiteren Ausführungsform,
• Figur 23 eine weitere Perspektivansicht der Gehäuseschale aus Figur 22,
• Figur 24 eine weitere Perspektivansicht der Gehäuseschale aus Figur 22,
• Figur 25 eine weitere Perspektivansicht der Gehäuseschale aus Figur 22,
• Figur 26 eine weitere Perspektivansicht der Gehäuseschale aus Figur 22,
• Figur 27 eine halbtransparente Perspektivdarstellung der Gehäuseschale der Figuren 22 bis 26, und
• Figur 28 eine Draufsicht auf die Gehäuseschale der Figuren 22 bis 27.

The invention is described in more detail below using an exemplary embodiment and with reference to the accompanying drawings. Shown in the drawings:

• Figure 1 a schematic perspective view of a belt buckle according to the invention;
• Figure 2 the belt buckle Figure 1 in a side view;
• Figure 3 the belt buckle Figure 1 in a top view;
• Figure 4 a first shell part of the housing of the belt buckle Figure 1 ;
• Figure 5 an electronic control module of the lighting device of the belt buckle Figure 1 ;
• Figure 6 a representation of the electronic control module mounted in the first shell part;
• Figure 7 a perspective view of a light guide of the belt buckle according to the invention Figure 1 ;
• Figures 8 and 9 Details of the light guide Figure 7 ;
• Figure 10 a variant of the light guide Figure 7 ;
• Figure 11 a front panel of the belt buckle Figure 1 ,
• Figure 12 a first shell part with a mounted light guide and a mounted front panel for the belt buckle Figure 1 ;
• Figure 13 the inside of a second shell part of the housing of the belt buckle Figure 1 ;
• Figure 14 a schematic sectional view of the belt buckle according to the invention Figure 1 ;
• Figure 15 a perspective view of a belt buckle according to the invention according to a further embodiment,
• Figure 16 Another perspective view of the belt buckle Figure 1 ,
• Figure 17 a perspective view of a housing part of the belt buckle from the Figures 15 and 16 ,
• Figure 18 another perspective view of the housing part Figure 17 ,
• Figure 19 another perspective view of the housing part Figure 17 ,
• Figure 20 another perspective view of the housing part Figure 17 ,
• Figure 21 another perspective view of the housing part Figure 17 ,
• Figure 22 a perspective view of a housing shell of a belt buckle according to a further embodiment,
• Figure 23 Another perspective view of the housing shell Figure 22 ,
• Figure 24 Another perspective view of the housing shell Figure 22 ,
• Figure 25 Another perspective view of the housing shell Figure 22 ,
• Figure 26 Another perspective view of the housing shell Figure 22 ,
• Figure 27 a semi-transparent perspective view of the housing shell Figures 22 to 26 , and
• Figure 28 a top view of the housing shell of the Figures 22 to 27 .

Figure 1 shows a belt buckle 10 with a housing 12, in which a tongue insertion opening 14 is provided for a tongue, not shown, of a seat belt system in a vehicle. The housing 12 encloses a support 16, on which an internal mechanism for fixing the tongue including a button 17 for releasing the tongue is mounted (see also Figure 14 ). The carrier 16 has a section which extends out of the housing 12 in the axial direction A and which serves to fasten the belt buckle 10 to the vehicle.

In the embodiment shown here, the housing 12 consists of several housing parts, namely a first shell part 18 (see also Figures 4 and 6 ) an opposite second shell part 20 (see also Figure 13 ) and a front panel 22 (shown in more detail in the Figures 11 and 12 ), which axially adjoins both shell parts 18.

In addition, the belt buckle 10 has a lighting device 24 (see Figure 14 ), which has a light guide 26 (see in detail Figures 7 to 10 ) and an electronic control module 28 (see in particular Figures 5 and 6 ).

The electronic control module 28 of the lighting device 24 has a control board 30 on which one or more LEDs are provided as lamps 32 as well as corresponding electronics 33, which can control the lamps 32 in terms of lighting duration, light intensity and, if necessary, light color. The lamps 32 can optionally be provided in just one color, or there can be several lamps 32 in different colors, which are controlled by the electronics 33 in such a way that any color is generated. The choice of color can be made depending on the situation, and color changes are also possible.

The electronic control module 28 is designed, for example, as a LIN module for connection to a LIN bus in the vehicle.

An electrical supply line 34 enables the electronic control module 28 to be supplied with electrical energy. The electrical supply line 34 is, for example, combined with a supply line for a switch (not shown) for detecting the inserted tongue.

In this example, the electronic control module 28 is fixed to the inside of the first shell part 18, for example by a snap or welded connection. A cable guide 36 is integrated into the inside of the first shell part 18 (see Figure 6 ) and also provides strain relief for the supply line 34.

The light from the lamps 32 is coupled into the light guide 26. For this purpose, the light guide 26 has an extension 38 which extends in the axial direction A away from the insertion opening 14 and which serves as a coupling element and which has a frontal coupling surface 40 at a free end into which the light emitted by the lamps 32 enters.

At its other end, the extension 38 merges into an annular section 42, which is circumferentially closed here.

In the area of the transition, a recess 44 designed as an opening in the annular section 42 is provided, here in the form of a triangle, the tip of which points towards the coupling surface 40. The sides 46 of the recess 44, which are directed obliquely to the axial direction A, serve to reflect the light entering the annular section 42 through the extension 38 in the circumferential direction into the annular section 42.

The end face 48 of the annular section 42 of the light guide 26 facing away from the extension 38 forms a light exit region 60. In this example, the end face 48 is designed to be flat.

In contrast, the end face 50 of the annular section 42 opposite the end face 48 has a structured surface here. In this example, a plurality of uniform structures 52 are placed next to each other, in which case the structures 52 are formed by prisms, each of which has a trapezoidal cross section and whose longitudinal direction is oriented transversely to the circumferential direction. This is in the Figures 8 and 9 indicated.

The structures 52 serve to reflect the light in the annular section 42 towards the front end face 48, where it is intended to leave the light guide 26.

Figure 10 shows a variant of a light guide 26 '. Here, the extension 38' is shorter, but the coupling surface 40' is wider, so that, for example, the light source 32 can more easily have several LEDs next to one another. It is also possible for several coupling surfaces 40' to lie next to one another or for a coupling surface to be present which extends in an arc around the lamp 32. The rear end face can also be structured or smooth here.

The first shell part 18 of the housing 12 has an annular projection 54 (see Figures 6 and 12 ), which runs around the tongue insertion opening 14. The projection 54 is formed in one piece with the remaining first shell part 18. The entire first shell part 18, but in particular the projection 54, is designed to be opaque in this example. Suitable materials for the first shell part 18, but also the other parts of the housing 12, are, for example, acrylonitrile butadiene styrene (ABS) or polypropylene (PP).

The light guide 26, 26' consists, for example, of polycarbonate (PC).

When assembling the belt buckle 10, the light guide 26 with its annular section 42 is plugged onto the projection 54 on the first shell part 18 and can be connected to the projection 54, for example by welding (ultrasonic or laser welding) or gluing.

Radiation of light from the light guide 26 radially inwards is prevented by the projection 54. The projection 54 extends in the axial direction A in this example at least to the end face 48 of the light guide 26 or even a little beyond that, as in Figure 14 can be recognized.

The front panel 22 of the housing 12 is also designed here as a circumferentially closed ring (see Figures 11 and 12 ) and is attached to the light guide 26 ( Figure 12 and Figure 14 ). Front panel 22 and light guide 26 are also fastened to one another in a suitable manner, for example by a snap-in, adhesive or welded connection, for example via ultrasonic or laser welding, and are firmly and non-detachably connected to one another.

The front panel 22 is designed to be opaque along its peripheral surface and thus blocks radiation of light from the light guide 26 in the radial direction r to the outside. The front panel 22 can be designed as a design element, for example with a chrome-plated outer surface or with a piano lacquer look. The front panel 22 is manufactured separately from the other housing parts, so that the appearance of the belt buckle 10 can be changed by providing a differently designed front panel 22.

On the tongue-side end face 56 of the front panel 22 there is a transparent, ring-shaped diffuser 58 surrounding the tongue insertion opening 14, through which the light emerging from the end face 48 of the light guide 26 penetrates to the outside. The diffuser 58 connects to the end face 48 of the light guide 26 in the axial direction A. An air gap is formed between the diffuser and the end face 48 of the light guide 26, which has a height of 0.25 mm in this exemplary embodiment.

The diffuser 58 can be designed in such a way that it influences the color of the emerging light and/or changes the radiation characteristics of the end face 48 of the light guide 26. However, it also ensures that the housing 12 is sealed to the outside without a gap and prevents dirt from penetrating into the housing 12. In this example, the diffuser 58 and the front panel 22 are therefore manufactured in one piece in a two-component injection molding process. For example, polycarbonate (PC) is used as a material for the diffuser. The front face of the diffuser is structured to improve the homogeneity of the light emission, i.e. fine-grained with a low roughness.

Instead of the light guide 26, the in Figure 10 light guide 26 'shown can be installed.

As a final assembly step, the second shell part 20 is connected to the first shell part 18, for example by a snap-in, adhesive or welded connection.

In the radial direction r, the width of the end face 48 is, for example, approximately 1 mm. The width of the diffuser 58 in the radial direction r is chosen here to be of the same order of magnitude. In this way, a light exit area 60 of the belt buckle 10 is created, which is formed circumferentially around the tongue insertion opening 14 and which is approximately 1 mm wide.

The projection 54 of the first shell part 18 and the front panel 22 prevent light from being emitted from the light guide 26 in the radial direction r, so that light only emerges from the light exit area 60 and the light exit area 60 forms the only illuminated section of the belt buckle 10.

The Figures 15 to 28 show further embodiments.

In the Figures 15 and 16 a belt buckle 100 is shown according to a further embodiment, the locking mechanism of the belt buckle 100, which interacts with a tongue, not being shown for reasons of clarity.

The belt buckle 100 has a belt buckle housing 112, which in the embodiment shown is designed in three parts.

The housing 112 has a first shell part 118, also known as the first housing shell, a second shell part 120, also referred to as the second housing shell, and a housing part which forms a front panel 122 and which has an edge 121 which has a receiving area 114 for a The tongue is surrounded by an insertion opening for the tongue.

The two shell parts 118, 120 together form a base body 123 of the housing 112, into which the front panel 122 is inserted. As a result, the two shell parts 118, 120 and the front panel 122 are coupled together so that they form the complete housing 112.

Furthermore, the belt buckle 100 has a lighting device 124, which includes a light source 132 and a light guide 126. The light source 132 can be an LED that emits red light, for example. Alternatively, a multicolored LED can also be provided so that the color of the emitted light can be adapted to the preferences of the vehicle occupant.

The light source 132 is provided within the belt buckle 100, being arranged on the first shell part 118. The light guide 126, on the other hand, is arranged in a housing section 129 of the housing 112, which is formed by the second shell part 120 in the embodiment shown. Therefore, the lamp 132 and the light guide 126 are arranged on different parts of the three-part housing 12.

The light guide 132 also has a coupling element 138, which in the assembled state of the belt buckle 100 is coupled to the light source 132 in such a way that the light emanating from the light source 132 is coupled into the light guide 126 via the coupling element 138.

The coupling element 138 is designed to taper in a wedge shape, whereby the coupling element 138 has a large coupling surface 140. The light coupled in via the coupling element 138 runs via the light guide 126 to an outcoupling surface 160, which is arranged at the edge 121 of the housing 112.

In the embodiment shown, the decoupling surface 160 is designed as a circumferential band on the edge 121, so that it encloses the insertion opening and the receiving area 122 in a ring.

The decoupling surface 160 in particular has a width of 0.5 mm to 1.5 mm, preferably 1 mm, and is arranged directly on the surface of the housing 112, which is in the field of view of the belt buckle 100 if this is a typical position in a vehicle takes.

In the Figures 17 to 21 the housing part corresponding to the front panel 122 of the first embodiment is shown separately.

From the Figures 17 to 21 It can be seen that the light guide 126, in addition to the coupling-out surface 160 and the coupling-in element 138, has a connecting structure 162, via which the front panel 122 can be coupled to the two shell parts 118, 120 or to the base body 123. The connecting structure 162 is formed at an end of the front panel 122 opposite the edge 121.

The figures also show that the light guide 126 is embedded in the front panel 122, since the light guide 126 is essentially surrounded by the housing material of the front panel 122. Only the coupling-out surface 160 on the edge 121 as well as the coupling-in element 138 and the connecting structure 162 are not surrounded by the housing material. The light-guiding structure of the light guide 126 therefore runs essentially inside the front panel 122, so that only the coupling-out surface 160, the coupling-in element 138 and the connecting structure 162 of the light guide 126 can be seen.

In the embodiment shown, the light guide 126 is therefore formed in one piece with the housing section 129 or the front panel 122.

The front panel 122 can therefore preferably be manufactured in a multi-component injection molding process. This ensures that the inner and outer housing surfaces of the front panel 122 are made of a first, opaque material, whereas the light guide 126 embedded therein is made of a second, light-conducting material. As a result, the light guide 126 is surrounded by the housing material of the front panel 122 or the front panel 122 and only has a single coupling-out surface 160.

The material for the light guide 126 can be, for example, high-tech refined plastics that have special light scattering, light guiding properties or an additional metallic effect.

In contrast, the first and second shell parts 118, 120 in this embodiment may have been manufactured in a one-component injection molding process, since they may be standardized components.

Alternatively, the light guide 126 can also be manufactured as a separate component and locked with the housing section 129 or the front panel 122. For this purpose, both the light guide 126 and the housing section 129 or the front panel 122 can have a latching structure.

In the Figures 22 to 28 the first shell part 118 of a belt buckle 100 is shown according to a further embodiment, which is only designed in two parts. Components that are the same or have the same effect are therefore provided with the reference numbers already introduced.

The housing 112, which is only partially shown, is therefore formed in this embodiment by the two shell parts 118, 120, of which only the first shell part 118 is shown.

The first shell part 118 has a housing section 164, which essentially corresponds to the front panel 122 in the first embodiment according to the Figures 15 to 21 corresponds. Analogous to the front panel 122 from the first embodiment, the housing section 164 has the circumferential edge 121 and the light guide 126, which is embedded in the first shell part 118 in the previous embodiment. The decoupling surface 160 of the light guide 126 is provided on the edge 121, analogous to the first embodiment, which is now arranged on the first shell part 118.

The first shell part 118 according to the previous embodiment therefore, in comparison to the first shell part 118 according to this embodiment, additionally has the front panel 122, which in this embodiment is formed in one piece with the first shell part 118 and is referred to as the housing section 162.

In this embodiment, the lamp is 132, which is in the Figures 25 to 27 is shown, also arranged on the inner surface of the first shell part 118. Accordingly, in this embodiment, both the lamp 132 and the light guide 126 are provided on the same housing section or part of the housing 12. This also applies to the coupling element 138, which interacts with the lamp 132 via its coupling surface 140.

The first shell part 118, since it has the light guide 126, has preferably been manufactured in a multi-component injection molding process. The light guide 126 is therefore essentially completely surrounded by the housing material of the first shell part 118 or essentially embedded in the first shell part 118.

The second shell part 120 in this embodiment, which is not shown in the figures, can be designed analogously to the second shell part 120 according to the previous embodiment and can be manufactured in a one-component injection molding process, since it can be a standardized component.

In the two-part embodiment according to Figures 22 to 28 the second shell part 120 is placed or pushed on and fixed with the first shell part 118, so that the complete belt buckle housing 112 is trained.

In general, in both embodiments of the belt buckle 100 it is provided that the parts forming the housing 112, i.e. the two shell parts 118, 120 and possibly the front panel 122, are placed on one another or pushed on or inserted in order to provide an easily detachable housing 112. This means that the lamp 26 can be replaced quickly and easily if necessary.

The components for the belt buckle mechanism, which interact with the tongue, are generally inserted into the first shell part 118 before the belt buckle 100 is assembled.

In general, the geometry of the light guide 126 and the optional insertion of lenses ensure that the decoupling surface 160 is homogeneously illuminated, so that a uniformly circumferential band of light marks the recording area 114, whereby it can be easily found by the vehicle occupant.

Furthermore, it can generally be provided that a chrome element is provided on the edge 121 in order to make the appearance of the belt buckle housing 112 appear more high-quality. The chrome element can be designed as a circumferential chrome ring and in particular can be arranged adjacent to the coupling-out surface 160 in such a way that the coupled-out light is reflected on the chrome surface. The chrome element is preferably provided next to the coupling-out surface 160 on the side of the coupling-out surface 160 facing away from the insertion opening 114.

The light source 132 can generally be designed as a type of pre-assembly unit, which means that electrical connections and optionally a series resistor are provided, which only need to be contacted when installing the belt buckle 100.

Claims (17)

1. A belt buckle comprising a housing (12) and a lighting unit (24) present in the area of a plug-in tongue insertion opening (14), wherein the lighting unit (24) comprises a lamp (32) and a light conductor (26; 26') having a light emission area and the light conductor (26; 26') includes an annular portion (42; 42') which surrounds at least a large part of the plug-in tongue insertion opening (14),

   characterized in that the annular portion (42; 42') of the light conductor (26; 26') is arranged radially inside of an at least largely peripherally closed front panel (22) of the housing (12), the front panel (22) framing the insertion opening (14),

   and in that the front panel (22) includes an annular, at least partially transparent diffusor (58) which is axially adjacent to the light emission area of the light conductor (26; 26').
2. The belt buckle according to claim 1, characterized in that the light emitting area is configured to be peripherally circumferential at an axial end face (48; 48') of the annular portion (42; 42') of the light conductor (26; 26').
3. The belt buckle according to any one of the preceding claims, characterized in that the light conductor (26) includes a structured surface at an end face (50) facing away from the light emission area.
4. The belt buckle according to claim 3, characterized in that the structured surface includes a plurality of structures (52), especially prisms, arranged side by side.
5. The belt buckle according to any one of the preceding claims, characterized in that the light conductor (26; 26') has an extension (38; 38') which projects axially from the annular portion (42; 42') of the light conductor (26; 26') and via which the light of the lamp (32) is coupled into the light conductor (26; 26').
6. The belt buckle according to claim 5, characterized in that in the area of the transition of the extension (38) into the annular portion (42) a recess (44) which is shaped so that the coupled light is evenly spread in the annular portion (42) is provided in the annular portion (42).
7. The belt buckle according to claim 1, characterized in that the front panel (22) with the exception of the diffusor (58) is opaque.
8. The belt buckle according to claim 1 or 7, characterized in that between the diffusor (58) and the light emission area of the light conductor (26; 26') an air gap is formed.
9. The belt buckle according to any one of the preceding claims, characterized in that the housing (12) includes a first shell member (18) having an annularly circumferential projection (54) which is arranged radially inwardly of the light conductor (26; 26').
10. The belt buckle according to claims 1 and 9, characterized in that the housing (12) consists of the first shell member (18), the front panel (22) and a second shell member (20).
11. The belt buckle according to any one of the preceding claims, characterized in that the lighting unit (24) comprises an electronic control module (28) in which the lamp (32) as well as an electronic system (33) are arranged, and especially wherein the electronic control module (28) is fastened to the inside of the first shell member (18) of the housing (12).
12. The belt buckle (100) according to any one of the preceding claims, characterized in that the light conductor (126) is connected to, especially locked with or permanently attached to the belt buckle housing (112).
13. The belt buckle (100) according to any one of the preceding claims, characterized in that the light conductor (126) includes a coupling element (138) which is coupled to the lamp (132) and is formed to be especially wedge-shaped.
14. The belt buckle (100) according to any one of the preceding claims, characterized in that the belt buckle housing (112) consists of several parts, wherein the light emission area of the light conductor (126) is provided at a rim (121) of the belt buckle housing (112) and is associated with a housing portion (129, 164) on which the rim (121) is formed.
15. The belt buckle (100) according to claim 14, characterized in that the light conductor (126) is substantially embedded in the housing portion (129, 164).
16. The belt buckle (100) according to claim 14 or 15, characterized in that the belt buckle housing (112) is formed in two parts and comprises two shell members (118, 120), with the housing portion (164) being provided at the first shell member (118).
17. The belt buckle (100) according to claim 14 or 15, characterized in that the belt buckle housing (112) is formed in three parts and comprises two shell members (118, 120) as well as an, especially insertable, front panel (122) on which the housing portion (129) is provided.

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