Abstract:
A beam light unit for vehicles, having a light module with a light source and a reflector, includes a downstream light output element to produce a predetermined light distribution. The light output element is mounted in a housing that leaves only a light outlet face of the light output element exposed, with sidewalls of the housing being in contact with jacket walls of the light output element immediately adjacent the light outlet face. Edge contours of the sidewalls correspond to a form of an edge of the light outlet face.

Description:
BACKGROUND OF THE INVENTION 
     This application claims a priority based on German applications 199 59 035.4, filed on Dec. 8, 1999, and 100 28 282.2, filed on Jun. 7, 2000, and the contents of those applications are incorporated herein by reference. 
     This invention relates to a beam light unit for vehicles having a light module with a light source and a reflector and having a downstream light output element to produce a predetermined light distribution. 
     German Patent Application DE 43 13 914 A1 discloses a beam light unit for vehicles having a housing in which a plurality of light output elements are arranged side by side. Each light output element serves to produce a predetermined light distribution. The light output elements are connected by a light guide to a light module which has a light source and a reflector. With the known beam light unit, no measures are provided for making the light output element sturdy and resistant to external environmental influences. 
     It is therefore an object of this invention to improve upon a beam light unit for vehicles such that the beam light unit has a sturdy and compact structure and is resistant to external environmental influences. 
     SUMMARY OF THE INVENTION 
     According to principles of this invention a light output element is mounted in a housing that exposes only a light outlet area of the light output element, with sidewalls of the housing being in direct contact with, or sealed with, jacket walls, or flat sidewalls, of the light output element adjacent to the light outlet face, with a front contour of the sidewalls corresponding to a shape of an edge of the light outlet face. 
     A particular advantage of this invention is that a sealed and secure mounting of the light output element is assured due to the housing walls which are in direct contact in an area of side surfaces of the light output element. A basic idea of this invention is to achieve a hermetic seal of lateral and rear faces of the light output element with respect to the environment, so that a risk of moisture condensing on these surfaces of the light output element is largely ruled out. In this way, an unwanted effect on reflective properties of the walls of the light output element can be reliably avoided. 
     According to a particular embodiment of this invention, the housing is structured in one piece in the form of a tunnel with a through hole, so that the housing walls extend around the light output element and form a seal, protecting the light output element from external ambient influences. The beam light unit is thus advantageously compact and simple to manufacture. 
     According to one embodiment of this invention, the housing is rotatably mounted in a U-shaped holding element that can be connected to a vehicle body part, thus assuring that the light unit can be easily aligned about a rotational axis. The legs of the U-shaped holding element are advantageously structured with spring resiliency, so that the housing or a light-output-element receptacle can be snap-locked onto the holding element. 
     According to another embodiment of this invention, the housing includes a continuous seal which is provided at a front edge area between the rest of the housing on the one hand and the adjacent jacket walls, or flat sidewalls, of the light output element, guaranteeing a tight seating of the light output element in the housing that remains stable over a long period of time. 
     According to another embodiment of this invention, the seal is made of a rubber elastic material which can adapt to the shape of the light output element. 
     According to another embodiment of this invention, the seal is integrally molded on an inside of the rest of the housing, so that by inserting the light output element into the opening in the housing, a secure seating of the light output element is guaranteed. 
     Additional advantages of the present invention are derived from other embodiments. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further benefits, characteristics and details of the invention are explained in more detail below using an embodiment shown in the drawings. The described and drawn features, can be used individually or in preferred combinations in other embodiments of the invention,. The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of the preferred embodiment of the invention, as illustrated in the accompanying drawings in which reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating principles of the invention in a clear manner. 
     FIG. 1 is a partially-cutaway schematic side view of a beam light unit according to a first embodiment of this invention; 
     FIG. 2 is a schematic side view of a beam light unit according to a second embodiment of this invention; 
     FIG. 3 is a front view of the beam light unit of FIG. 2; 
     FIG. 4 is a longitudinal partial section taken on line IV—IV of the beam light unit if FIG. 3; 
     FIG. 5 is a longitudinal section taken on line IV—IV in FIG. 3, but only showing a light-output-element receptacle and a gasket arranged between the receptacle and a lateral face of the light output element; and 
     FIG. 6 is a view similar to FIG. 1 in an alternate embodiment. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A beam light unit for vehicles includes primarily a light module  1  which is connected by a light guide  2  to a light output element  3 . The light module  1  has a light source  4  arranged at a focal point of an elliptical reflector  5 . Light produced by the light source  4  is focused by the reflector  5  on a light input face of the light guide  2  so that the light is transmitted into the light guide  2 , is output into the light output element  3  at the other end  6  thereof and is then radiated through a light outlet face  7  of the light output element  3  so that a desired light distribution is achieved. 
     The light output element  3 , according to this embodiment, serves to produce a widely diffused light distribution, for example, as a fog light. It has two parallel sidewalls  8  which are linked together opposite one another by perpendicular walls  9  which diverge from one another in a light-propagation direction. Since the perpendicular walls  9  are rectangular in shape, the light output element  3  is also structured with a rectangular cross section. The light outlet face  7  is convex in shape relative to a plane perpendicular to the sidewalls  8 . 
     To protect against mechanical stresses, the light output element  3  is mounted in a housing  10  which is adapted to the shape of the light output element, completely surrounding the light output element  3 . Only the light outlet face  7  of the light output element  3  and a rear connecting part to the light guide  2  are exposed. 
     To prevent moisture from penetrating into the housing  10 , the housing includes a gasket  11  in the form of a peripheral gasket flush at a front edge of the housing  10 , extending between the edge of the rest of the housing and the light output element  3 . The gasket  11  is made of a rubbery elastic material which is integrally molded onto an inside of the rest of the housing  10 , preferably by a two-step injection molding method. This provides a stationary and position-secure arrangement of the gasket  11 , which simplifies insertion of the light output element  3  into the housing  10 . 
     In a rear area of the light output element  3 , where the light output element  3  becomes a cylindrical part, another gasket is structured as an O-ring  12 , which is arranged between the inside of the housing  10  and the light output element  3 . It extends in a circle around the light output element  3  and facilitates central positioning of the light output element  3  inside the housing  10 . The O-ring  12 , like gasket  11 , is injection molded onto the inside of the housing  10 . 
     The housing  10  is mounted in a pot-shaped housing receptacle  13 , having a connector  14  which can be snap-locked onto the end  6  of the light guide  2 . The housing receptacle  13  has two opposing catch arms  15  which engage with recesses (not shown) in perpendicular walls in a connection area  16  and by forming a radial force component pressing against the opposing perpendicular walls. This provides a self-locking mount of the housing  10  in the housing receptacle  13 . The light output element  3  is mechanically protected in this way and can be easily attached into a vehicle body opening of a vehicle because of the simple geometric structure (rectangular shape) of the housing receptacle  13 . The light output element  3  therefore has a sturdy and compact structure, with the housing receptacle  13  also serving as a buffer with respect to unwanted collisions. 
     In a rear area of the connection  14 , it is sealed by another O-ring  12  with respect to the light guide  2 , so that no moisture can penetrate into the housing  10  or the housing receptacle  13  from the back side. 
     As shown in FIG. 1, the light module  1  has a housing  17  which is connected to a light-guide receptacle  18 . The light guide  2  is structured as a flexible light guide  2 . 
     According to an alternate embodiment, the light guide  2  may also be structured to be rigid and straight, so that the light-guide receptacle  18  and/or the housing  10  may be connected in one piece to the housing receptacle  13 . FIG. 6 depicts the light-guide receptacle  18  and the housing receptacle  13  connected as one piece, although the light guide is not straight. For this case, the O-rings  12 ′ may be omitted. The same is true of an embodiment in which the light module  1  is connected directly to the light output element  3 , omitting the light guide  2 . The light output element  3  is made of a light-transmissive, or transparent, material, preferably glass or Polymethylmethacrylate PMMA, with a back side being reflectively coated. 
     As an alternative, the housing  10  may also be held inside the housing receptacle  13  by a screw connection. Both the housing  10  and the housing receptacle  13  are made of a relatively rigid, non-transparent plastic material. 
     The beam light unit according to this invention is preferably suitable as an auxiliary automotive beam light which is subsequently mounted on a vehicle body, preferably in a body opening. 
     With a one-piece structure of the housing receptacle  13 , the light-guide receptacle  18  and the housing  17  of the light module  1 , it is possible in an advantageous manner to reduce the cost of achieving a seal for the light output element  3 . 
     According to another embodiment of the beam light unit according to FIGS. 2 through 5, a light output element  20  has a fog light function. The light output element  20  has two opposing parallel jacket walls  21 , or flat sidewalls, at whose surfaces beams of light input by the light guide  2  are totally reflected internally before leaving the light output element  20  through a curved light outlet face  22  of the light output element  20 . In a rear area  23  of the light output element  20 , the curved light output face  22  transitions into a straight face which is also a jacket wall  21  which does not output light. 
     The light output element  20  is mounted in a one-piece housing  24  which sealingly grips about the jacket walls  21  of the light output element  20 . The housing  24  is structured as a tunnel-shaped light-output-element receptacle with a through hole  25  to accommodate the light output element  20 . The light-output-element receptacle housing  24  has long and short sidewalls  26  and  27  which lie directly on the jacket walls  21  of the light output element  20 . In this regard, the long and short sidewalls  26 ,  27  essentially cover the flat, or even, jacket walls  21  of the light output element  20 . A front contour  28  of the long and short sidewalls  26 ,  27  substantially corresponds to an edge  29  of the light outlet face  22  of the light output element  20 . Thus, the entire surface of the light output element  20  except for the light outlet face is sealingly, and protectively, covered. 
     To increase the sealing effect, the housing  24  has a surrounding gasket  30  in the area of the front contour  28  of the sidewalls  26 ,  27 , extending between the sidewalls  26 ,  27  and the jacket walls  21  of the light output element  20 , where it is compressed. 
     For an accurately-positioned light-technical coupling of the light output element  20  to a cylindrical end  31  of the light guide  2 , a light-guide receptacle  32  is provided, having a C-shaped fastening element  33  on a side facing the light output element  20 , the fastening element being attached to a rear side of the light-output-element receptacle  24  by a form-fitting or clamping action. To this end, an outer edge  34  of the C-shaped fastening element  33  engages at a rear area of the through hole  25  with, for one thing, the inside of the light-output-element receptacle  24  contacting it and, for another thing, butt engagement being made at a rear side of the light output element  20 . 
     To assure a sealed and secure seating of the cylindrical end  31  in the light-guide receptacle  32 , it has a hollow cylindrical shoulder  35  in which the cylindrical end is clamped by a sleeve  36  surrounding a circumferential surface thereof. The sleeve  36  may be made of a flexible material. 
     The cylindrical end  31  is supported in the light-guide receptacle  32  in such a way that an end face  37  of the cylindrical end  31  is in surface contact with a rear end of the light output element  20 . 
     For mounting the light unit on a vehicle body part (not shown), a U-shaped holding element  38  is provided which can be attached at a middle area  39  to the body part by a screw  40 . The holding element  38  has opposing spring legs  41  with openings into which are snap connected bulges  42  on the long sidewalls  26  of the light-output-element receptacle  24 . An imaginary connecting line between the bulges  42 , or openings, in the leg ends  41  forms an axis of rotation which is perpendicular to an optical axis and intersects it. Preferably, the axis of rotation extends horizontally so that a height of the housing  24  with the light output element  20  is adjustable. 
     The light outlet face  22  of the light output element  20  may have a coating to prevent abrasion. The coating may be produced by spraying or molding onto the light outlet face  22  or by applying a film.