Abstract:
A vehicle lamp includes a lamp housing which can be introduced into a bodywork opening until an abutment provided thereon comes to bear against a part of the vehicle. A sealing means in the installed condition sealingly closes the bodywork opening. At least one latching means engages behind the edge of the bodywork opening to prevent the vehicle lamp from moving out of the bodywork opening. To reduce the tolerance requirements the lamp housing comprises first and second housing portions of which the first has the abutment and the latching means and the second has the sealing means. The housing portions are displaceable relative to each other in the installation direction from a pre-assembly position into a final assembly position. A bistable spring arrangement mounted on them urges the housing portions in the pre-assembly position away from each other in opposite relationship to the installation direction and in the final assembly position pulls them towards each other in the installation direction in such a way that the sealing means is pressed from the exterior against the outside surface of the bodywork.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the priority of German patent application Serial No. 10 2005 006 824.3 filed Feb. 15, 2005.  
       FIELD OF THE INVENTION  
       [0002]     The invention concerns a vehicle lamp.  
       SUMMARY  
       [0003]     There is provided a vehicle lamp including a lamp housing which can be introduced from the exterior into a bodywork opening until an abutment provided thereon comes to bear against a part of the vehicle, and a sealing means for sealingly closing the bodywork opening. At least one latching means for engaging behind the edge of the bodywork opening to prevent the vehicle lamp from moving out of the bodywork opening. The lamp housing further comprises first and second housing portions. The first housing portion includes the abutment and the at least one latching means, while the sealing means is provided on the second housing portion. The two housing portions are so mounted to each other that they are displaceable relative to each other in the installation direction from a pre-assembly position into a final assembly position. A bistable spring arrangement is mounted on the housing portions in such a way that in the pre-assembly position it urges the housing portions away from each other in opposite relationship to the installation direction and in the final assembly position it pulls them towards each other in the installation direction in such a way that the sealing means is pressed from the exterior against the outside surface of the bodywork.  
         [0004]     As will be apparent from the description of the embodiments, the first and second housing portions, which are displaceable relative to each other in the insertion direction, are provided for supporting and providing latching engagement in the region surrounding the opening in the bodywork as well as for sealing closure of the opening in the bodywork. The first housing portion has an abutment which prevents the vehicle lamp from being inserted into the bodywork opening to an excessive depth in the assembly operation. Also provided on the first housing portion are the latching devices which engage behind the edge of the bodywork opening, when the vehicle lamp is completely inserted. The spacing thereof from the surface of the abutment, which comes to bear against the outside of the bodywork, is completely non-critical as the abutment as such does not perform any sealing functions.  
         [0005]     Rather, a sealing function is associated with the second housing portion, which is urged outwardly in opposite relationship to the insertion direction with respect to the first housing portion by the bistable spring arrangement. When the vehicle lamp is introduced into the bodywork opening to such an extent that the abutment of the first housing portion comes to bear against the outside of the bodywork, the application of a further force acting in the insertion direction, against the second housing portion, means that the latter can be displaced in relation to the first housing portion until the bistable spring arrangement moves beyond its dead point. The spring arrangement then exerts a force which biases the second housing portion in the insertion direction relative to the first housing portion. Therefore, the first housing portion is pressed with its latching devices against the inside of the bodywork while at the same time the second housing portion is pressed with its sealing arrangement against the outside of the bodywork. In a final assembled condition, there is no longer any need for the abutment of the first housing portion to bear against the outside of the bodywork as the sealing function is performed entirely by the sealing arrangement of the second housing portion.  
         [0006]     The above-described spring action in the installation direction thus permits advantageous tolerance compensation and allows relatively large manufacturing tolerances for the functional elements which serve for fixing purposes.  
         [0007]     The pressing force of the sealing arrangement can be varied within wide limits according to the respective requirements involved, by making the spring force of a suitable magnitude. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is a cross-sectional view of a vehicle lamp in a pre-assembly condition taken along line I-I of  FIG. 5 .  
         [0009]      FIG. 2  is a cross-sectional view corresponding to  FIG. 1 , showing the vehicle lamp of  FIG. 1  in a finished assembled condition,  
         [0010]      FIG. 3  shows a cross-sectional view of the vehicle lamp in a pre-assembly condition taken along section line III-III in  FIG. 5 ,  
         [0011]      FIG. 4  is a cross-sectional view corresponding to  FIG. 3  of the vehicle lamp in the finished assembled condition, and  
         [0012]      FIG. 5  is a diagrammatic rear view of the vehicle lamp of FIGS.  1  to  4 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0013]     Referring to  FIGS. 1 through 4 , a part of a body  1  of a vehicle with a bodywork opening  3  into which a vehicle lamp  5  inserted from the front, is shown, in a pre-assembly condition in  FIGS. 1 and 3  and in a definitively assembled condition in  FIGS. 2 and 4 .  
         [0014]     As can be seen from  FIGS. 1-4 , vehicle lamp  5  has a lamp housing comprising two housing portions  8  and  10  which are displaceable relative to each other in parallel relationship with the insertion direction, i.e. from right to left or left to right.  
         [0015]     First housing portion  8  has an abutment indicated at  12  in  FIG. 1  which projects transversely with respect to the insertion direction in the form of a peripherally extending, partially interrupted flange or collar in order to limit the insertion depth of first housing portion  8  into bodywork opening  3  by virtue of abutment  12  coming to bear against an outside surface  13  of the bodywork in the region surrounding bodywork opening  3 .  
         [0016]     Alternatively abutment  12  of first housing portion  8  can be designed such that it comes to bear against another fixed part of the vehicle, within the bodywork.  
         [0017]     In one embodiment, first housing portion  8  is substantially in the form of a hollow body which is open at its two ends.  
         [0018]     As can be seen in particular from  FIGS. 3 and 4  first housing portion  8 , has latching noses  14  and  15  which have inclined ramp surfaces on their rear sides that are remote from bodywork opening  3 , and steep abutment surfaces on their sides that are towards an inside surface  17  of the bodywork. In the fully inserted condition shown in  FIGS. 3 and 4  latching noses  14  and  15  project transversely with respect to the insertion direction to such an extent that their abutment surfaces which engage behind the edge of bodywork opening  3  ensure that first housing portion  8  cannot be readily pulled out of bodywork opening  3  towards the right again.  
         [0019]     Latching noses  14  and  15  are disposed at the front free end of tongues  16  and  16   a  which are formed by incisions in the outside wall of first housing portion  8 . Upon insertion of first housing portion  8  into the bodywork opening  3 , when the inclined ramp surfaces of the latching noses  14  and  15  pass over the edge of bodywork opening  3 , tongues  16  and  16   a  are deflected resiliently inwardly to such an extent that the latching noses  14  and  15  can pass readily through bodywork opening  3 .  
         [0020]     The distances of the steep abutment surfaces of latching noses  14  and  15  from the rear side, which faces theretowards, of abutment  12  formed by the peripherally extending flange or collar, are completely non-critical and only have to be somewhat larger than the thickness of the sheet metal of the bodywork in the region of bodywork opening  3  so that latching noses  14  and  15  can readily resiliently engage behind inside surface  17  of the bodywork when first housing portion  8  is pushed into bodywork opening  3  to such an extent that the abutment  12  comes to bear against outside surface  13  of the bodywork. As will be described in greater detail hereinafter, the rear side of abutment  12  on the one hand and the steep abutment surfaces of latching noses  14  and  15  on the other hand come to bear against the surface of the sheet metal of the bodywork, which respectively faces theretowards, in various phases which occur in temporal succession in the assembly procedure, but never at the same time.  
         [0021]     In the embodiment shown in  FIGS. 1 through 4 , first housing portion  8  carries a circuit board  18  on which is mounted a plurality of light emitting diodes  20  forming the light sources of vehicle lamp  5  according to the invention. Circuit board  18  can be in the form of a printed circuit board which is provided on one or both flat sides thereof with conductor tracks which provide for the power supply to light emitting diodes  20 .  
         [0022]     Furthermore, first housing portion  8  is integrally connected to elements  21  which have an optical function and which, in the embodiment shown, have Fresnel lenses which parallelize the light coming from corresponding light emitting diodes  20  in such a way that it issues from vehicle lamp  5 , without substantial losses.  
         [0023]     It is also possible to provide reflectors which partially embrace the light sources and may be integrally connected to first housing portion  8 . Instead of light emitting diodes  20  it is also possible to use incandescent lamps as the light sources.  
         [0024]     As can be seen from  FIGS. 1 through 4 , second housing portion  10  is also in the form of a hollow body. Its external contour and its external dimensions are so matched to the internal contour and the internal dimensions of first housing portion  8  that it can be slidingly and guidedly displaced therein in parallel relationship with the insertion direction.  
         [0025]     As can be seen from  FIGS. 3 through 5 , the axial length of second housing portion  10 , extending in the insertion direction, over the major part of the width of vehicle lamp  5  which extends perpendicularly to the plane of the drawing in  FIGS. 3 and 4 , is of such a magnitude that the outside wall of second housing portion  10  blocks latching noses  14  and  15  in the fully inserted condition shown in  FIG. 4 , so that they cannot come out of engagement with inside surface  17  of the bodywork. When vehicle lamp  5  is inserted into bodywork opening  3 , the above-described blocking effect does not occur as shown in  FIG. 3 , second housing portion  10 , in the pre-assembly condition shown therein, is displaced towards the right with respect to first housing portion  8  to such an extent that its end is still outside bodywork opening  3 .  
         [0026]     In order for two housing portions  8  and  10  to be joined to form a unit in the pre-assembly condition, second housing portion  10  has two respective extension arms  25  and  26  which are arranged in mutually diametrally opposite relationship with respect to longitudinal axis  23  of the housing. In the insertion direction, extension arms  25  and  26  extend beyond the end of the hollow body forming second housing portion  10 , thereby extending its external contour. Extension arms  25  and  26  bear against the inside wall of first housing portion  8  and ensure a guidance action for the above-mentioned mutual displacement of housing portions  8  and  10 . In the region of extension arms  25  and  26 , first housing portion  8  does not include latching noses which engage behind the sheet metal of the vehicle bodywork.  
         [0027]     In the embodiment shown in  FIGS. 1 and 2 , the extension arms  25  and  26  each have respective latching nose  28  and  29  for engaging corresponding openings  30  and  31  in the wall of first housing portion  8 . In this respect, the surfaces of latching noses  28  and  29 , are so steep that they cannot pass over the wall surfaces, which are in opposite relationship thereto, of openings  30  and  31 . Therefore second housing portion  10  cannot be further withdrawn from first housing portion  8 .  
         [0028]     Adjoining openings  30  and  31  in the insertion direction (i.e. towards the left in  FIGS. 1 and 2 ) are passages  32  and  33  which are formed in the inside wall of first housing portion  8 . The height of passages  32  and  33  is of such a magnitude that latching noses  28  and  29  can readily slide towards the left therein when second housing portion  10  is displaced out of the pre-assembly position shown in  FIG. 1  and  FIG. 3  into the final assembly position shown in  FIG. 2  and  FIG. 4 .  
         [0029]     Two shape springs  34  and  35  which are Ω-shaped in the embodiment shown in  FIGS. 1 and 2 , are pivotably mounted to the end of first housing portion  8  and the corresponding ends of extension arms  25  and  26 , in such a way that, upon insertion of second housing portion  10  into first housing portion  8 , springs  34  and  35  can be pivoted out of the position shown in  FIG. 1  about pivotal mounting points  37  and  38  and  39  and  40 , respectively, into the position shown in  FIG. 2 .  
         [0030]     The position of pivotal mounting points  37  and  40  on first housing portion  8  with respect to pivotal mounting points  38  and  39  on second housing portion  10  is such that shape springs  34  and  35 , in the pre-assembly position shown in  FIG. 1 , exert a force which displaces second housing portion  10  towards the right with respect to first housing portion  8  to such an extent that latching noses  28  and  29  come to bear with their steep end faces against the right-hand inside surfaces of openings  30  and  31 .  
         [0031]     If a force acting in the insertion direction is applied to second housing portion  10  after insertion of vehicle lamp  5  into bodywork opening  3 , shape springs  34  and  35  transmit that force to first housing portion  8 . Abutment  12  of first housing portion  8  bears against outside surface  13  of the bodywork and, therefore, first housing portion  8  cannot slide more deeply into bodywork opening  3 . In the course of the movement, further stressing of the shape springs  34  and  35  takes place until a dead point position is reached. After springs  34  and  35  move beyond that position, they pivot further about pivotal mounting points  37 ,  38  and  39 ,  40  until they have reached the position shown in  FIG. 2  wherein shape springs  34  and  35  apply a force to second housing portion  10  in the insertion direction with respect to first housing portion  8 . A reaction force is exerted on first housing portion in the opposite direction and is carried by latching noses  14  and  15 , which are supported against inside surface  17  of the bodywork.  
         [0032]     The above-described embodiment provides a bistable spring arrangement that pivots from a pre-assembly position into a final assembly position and reverses the direction of the force exerted thereby between housing portions  8  and  10 .  
         [0033]     As shown in  FIGS. 1 through 4  an outer side, of second housing portion  10  has a flange  42  which projects transversely with respect to the insertion direction and which carries a sealing ring  44  on its side that faces towards outside surface  13  of the bodywork. As shown in  FIGS. 2 and 4 , sealing ring  44  is pressed against outside surface  17  of the vehicle bodywork in a moisture-tight manner by the force of shape springs  34  and  35 , in the final assembly condition. The end of the hollow body formed by second housing portion  10  is sealingly closed by a light transmission cover  46 , which can be provided in one piece with the second housing portion  10 . Therefore a moisture-tight closure for the bodywork opening  3  is provided.  
         [0034]     In order to ensure that the pressing effect of sealing ring  44  is always uniform, the spacing of flange  42  from outside surface  13  of the vehicle bodywork can be kept constant by way of additional spacer elements  48  provided at the outer ends of flange  42 , spacer elements  48  bear against outside surface  13  of the vehicle bodywork in the final assembly condition.  
         [0035]     Removal of vehicle lamp  5  can be effected by withdrawing second housing portion  10 , against the force of springs  34  and  35 , with a special tool which engages into suitable apertures in second housing portion  10 . Thereafter latching noses  14  and  15  on first housing portion  8  are accessible for disengagement. Vehicle lamp  5  can then be drawn out of bodywork opening  3 .  
         [0036]     Instead of Ω-shaped springs  34  and  35  it is also possible to use wire loop springs, shape springs having a U-shaped configuration, torsion springs, compression springs, etc. By virtue of arranging an elongate shape spring with two outer pivotal mounting points on one housing portion and a central pivotal mounting point on the other housing portion, the desired function can also be performed with a reduced number of springs.  
         [0037]     It will be appreciated that the above-described embodiments have been set forth solely by way of illustration and example and that various alterations and modifications may be made without departing from the spirit and scope of the invention.