MOTOR VEHICLE LAMP

FIELD OF THE INVENTION

The invention relates to the field of motor vehicle lamps, and more specifically to a motor vehicle halogen lamp for use in a motor vehicle headlight. BACKGROUND OF THE INVENTION From US 2005/0041420 Al a motor vehicle lamp is known, which comprises a halogen burner received by a holder. The holder comprises a clamping member comprising a recess into which a pinch seal of a glass body of the burner is fitted. The clamping member is connected to a socket of the holder which is shaped to be connected to a motor vehicle lamp housing of a motor vehicle headlight. The halogen burner comprises connectors for applying an electric current, which protrude from the pinch seal and are connected to broader contact lugs inside the socket of the holder. By means of the intermediary contact lugs an electric source may be applied to the burner for emitting light. The contact lugs are fastened by a synthetic resin cap connected to the socket of the holder. By means of the synthetic resin cap the metallic parts of the holder are insulated against the connectors of the burner as well as against the contact lugs. Since the space for the burner inside the motor vehicle headlight is small and the burner of the motor vehicle headlight may be in use for a long time, motor vehicle headlights become very hot. For that reason the synthetic resin cap is made of a plastic material selected with respect to a good heat resistance, for instance PPS (polyphenylene sulfide, (SC6H ₄ ) _n ). However PPS and comparable materials are expensive leading to high production costs.

There is a permanent need to reduce production costs of the manufacture of motor vehicle lamps. SUMMARY OF THE INVENTION

It is an object of the invention to provide a motor vehicle lamp that may be produced in a more cost efficient manner.

The object is achieved according to the invention by a motor vehicle lamp comprising a burner for emitting light and a holder by which the burner is received, the holder being adapted to be inserted into a recess of a motor vehicle lamp housing, wherein the burner comprises a pinch seal, from which at least two connectors protrude for applying an electric current, wherein the connectors comprise a length in axial direction of the burner chosen such, that each connector is adapted to being directly connected only to a contact member of the motor vehicle lamp housing for applying an electric source to the burner via the connectors.

Due to their increased length the connectors of the burner may be directly connected to the contact members of the motor vehicle housing, so that intermediary contact lugs are omitted. The length L of the connectors from the end of the pinch seal of a glass body of the burner to the free ends of the connectors may be 1.0 cm < L < 7.0 cm, particularly 2.0 cm < L < 6.0 cm, preferably 2.5 cm < L < 5.0 cm, most preferred 3.0 cm < L < 4.5 cm and for example L=4.0 cm ± 0.2 cm. Further it is possible that the motor vehicle lamp omits a synthetic resin cap or the like made of PPS or comparable materials since the connectors may be arranged spaced to further electric conductive materials. Ambient air as dielectric provides a sufficient insulating. Particularly the connectors may be supported only by the pinch seal on the one end and in assembled state by the contact member of the motor vehicle housing on the other end. If so, the contact member may be embedded into a synthetic resin like PPS, so that the used PPS is not wasted after an exchange of the motor vehicle lamp. Due to the reduced number of assembling components the material costs and the assembling costs are decreased. Further the shape of the components of the motor vehicle lamp may be simplified since a lower number of parts have to be connected to each other. Especially expensive materials may be recycled. This leads to a motor vehicle lamp that may be produced in a more cost efficient manner.

Preferably the cross-section of each connector is substantially constant over the length of the respective connector. It is not necessary to amend the shape and the area of the cross-section of the connectors to provide a good contact with the

contact member of the motor vehicle housing. Especially it is not necessary to amend the shape of the connectors such, that broader contact lugs are formed. Since a motor vehicle lamp is normally inserted into a motor vehicle housing only once it is no problem when the connectors may deform under stress. Due to the lack of a further need for inserting the motor vehicle lamp a further time the requirement of not deformable connectors is rendered unnecessary. Particularly at least one filament, preferably two filaments of a halogen burner is/are directly connected to the contact member of the motor vehicle housing only via the connectors led through the pinch seal of the glass body of the burner. In order to simplify the connection of the connectors to the contact member of the motor vehicle housing the cross-section of at least one connector may be rectangular particularly quadratic. Due to the shape of the connectors a planar contact to the contact member is possible, so that the electrical contact is increased. Further a mechanical connection for instance by clamping may be provided at the same time by means of the contact member.

In a preferred embodiment of the invention the connectors of the motor vehicle lamp are adapted to safeguard a connection to the contact member in a correct alignment, so that it is prevented to erroneously connect the wrong poles to the connectors. For that reason preferably the cross-section of at least two connectors are shaped different to each other. Further it is possible that the radial distances to the holder of at least two connectors may be different to each other. When the motor vehicle lamp is turned the connectors may be moved along to different circular line until they are arranged to be connected to the contact member in the correct alignment. The same effect may be provided if particularly at least three connectors are provided and the distances between two nearby connectors are different to each other.

In a preferred embodiment of the invention the holder comprises a clamping plate for receiving the burner and an adjusting plate for adjusting the alignment of the burner. The clamping plate and/or the adjusting plate are preferably adapted to be made by deep drawing and/or stamping. The clamping plate may comprise clamping members for example clamping lugs which are one-piece with the clamping plate. By means of the clamping plate the pinch seal of the hollow glass body of the burner may be

received. In order to prevent an unintended detaching of the burner from the clamping plate the burner may comprise, preferably in the area of the pinch seal, at least one ridge or the like to lock tight the burner with the clamping plate at a predetermined height. By means of the adjusting plate the alignment of the burner may by adjusted for example by an intended deforming of the adjusting plate with respect to at least one reference preferably to three references. This deformation may by performed by applying heat by means of a laser light or the like. Preferably the clamping plate and the adjusting plate are one-piece. In the case, that the clamping plate and the adjusting plate are not one- piece, the clamping plate is preferably fixed non-detachably to the adjusting plate particularly by laser welding. Most preferred the fixing of the clamping plate to the adjusting plate is made such that the correct alignment of the burner is taken into account. The adjustment of the burner may be at least partially performed during the connection of the clamping plate to the adjusting plate.

The invention further relates to a motor vehicle headlight comprising a motor vehicle lamp housing comprising a recess, by which a motor vehicle lamp, which may be designed as previously described, is received via the holder, and at least one contact member for applying an electric source to the burner via the connectors, wherein the connection of the holder to the motor vehicle housing and the connection of the connectors to the contact members are provided by an axial relative movement of the motor vehicle lamp with respect to the recess of the motor vehicle housing. Since an axial movement of the motor vehicle lamp is sufficient for providing an electrical and mechanical contact to the motor vehicle housing at the same time the motor vehicle headlight is easy to assemble. Particularly the holder is shaped such that an axial movement is only in the correct alignment possible. An unintended turning of the motor vehicle lamp may be prevented by the shape of the holder so that an easy contact of the connectors to the contact member without the danger of deforming the connectors is safeguarded. Particularly the contact member is at least partially embedded into a heat resistive insulating material preferably PPS. Since the contact member may be embedded into a synthetic resin like PPS the used PPS is not wasted after an exchange of the motor vehicle lamp. Further an improved electrical insulation is provided and the heat of the motor vehicle lamp does not affect the motor vehicle housing.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. In the drawings:

Fig. 1 is a perspective partial sectional view of a motor vehicle lamp according to the invention,

Fig. 2 is a sectional side view of the motor vehicle lamp illustrated in Fig. 1 in assembled state,

Fig. 3 is a sectional side view of a detail of the motor vehicle lamp illustrated in Fig. 2 and Fig. 4 is a perspective view of the motor vehicle lamp illustrated in Fig.

1 in assembled state.

DETAILED DESCRIPTION OF EMBODIMENTS

The motor vehicle lamp 10 according to the invention is illustrated in Fig. 1 exemplary on the basis of a motor vehicle lamp 10 according to the H4-standard. The motor vehicle lamp 10 comprises a burner 12 mechanically connected to a holder 14. The burner 12 comprises a glass body 16 with a pinch seal 18. Inside the hollow glass body 16 a first filament 20 and a second filament 22 for emitting light are arranged. A first connector 24 and a second connector 26 are connected to the first filament 20, while the first connector 24 and a third connector 28 are connected to the second filament 22. The second connector 24 and the third connector 28 are adapted to be connected to different poles, while the first connector 24 is connected to ground. Between the end of the pinch seal 18 and their free ends the connectors 24, 26, 28 comprise a length L. Preferably each connector 24, 26, 28 comprises the same length L as illustrated. Further the cross-section of the connectors 24, 26, 28 are constant and may be particularly rectangular shaped. The distances of the connectors 24, 26, 28 to each other and/or to the holder 14 may differ.

The holder 14 comprises a clamping plate 30 by which the glass body 16 of the burner 12 is mechanically fastened in the area of the pinch seal 18. In the illustrated embodiment a cylindrical socket 32 is connected to the clamping plate 30 by crimping. To the socket 32 an adjusting plate 34 is connected by laser welding via welded connecting spots 36. The holder 14 comprises a fastening means 38 for fastening the adjusting plate 34 to a motor vehicle housing.

In assembled state as illustrated in Fig. 2 the connectors 24, 26, 28 are electrically and mechanically connected to a connector means 40 embedded into a plug 42 made of a synthetic heat resistant insulating material like PPS. Wires 44 connect the contact member 40 to an electric source.

As illustrated in Fig. 3 the holder 14 and the plug 42 may be shaped such that an unintended turning of the motor vehicle lamp 10 with respect to the plug 42 of the motor vehicle housing is prevented. For that reason the plug 42 may comprise a protruding lip 46 adapted to be received by a corresponding recess 48 of the holder. The recess 48 may be arranged in the cylindrical socket 32 as illustrated in Fig. 4.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. For example, it is possible to operate the invention in an embodiment wherein the connectors 24, 26, 28 comprises different lengths L and/or the length L is significantly varied chosen in dependence of the design of the motor vehicle housing for which the motor vehicle lamp 10 should be used. Further the cylindrical socket 32 may be omitted and the clamping plate 30 may be directly connected to the adjusting plate 34. Especially it is possible that the clamping plate 30 and the adjusting plate 34 are one- piece. Further if the socket 32 is provided, the socket 32 may be one-piece with the clamping plate 30 and/or the adjusting plate 34.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not

exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.