Abstract:
A light assembly includes a lighting module having a number of LEDs and a reflector assembly disposed on the lighting module. The reflector assembly includes a number of individual reflector portions, each reflector portion being of generally concave shape and structured to selectively direct light emitted from a respective one of the number of LEDs. A lens member is disposed over the reflector assembly and a membrane is disposed between the reflector member and the lens.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to lights and reflector assemblies. More particularly, the present invention relates to an LED and reflector assembly for use in signal applications, such as those used with railways. 
     2. Description of the Prior Art 
     The railroad industry utilizes wayside signals to indicate authorization for trains to proceed or to stop at certain positions on railroad tracks. Such wayside signals have commonly utilized incandescent lamps to provide indications, such as to proceed or stop, to trains. 
     The use of incandescent lamps in wayside signals results in certain drawbacks. First, the life of incandescent lamps is relatively short, i.e., an incandescent lamp typically burns out in a relatively short period of time of approximately 6 to 12 months. This may be particularly problematic in wayside signals for railways as such signals may often be placed at remote locations along railway tracks. As a result, it is often inconvenient and time consuming for maintenance personnel to replace a burned out wayside signal. Additionally, any time a wayside signal burns out, safety concerns are raised and the use of certain railroad track sections may be prohibited, resulting in a loss of operating efficiency of the railway due to track re-routings. A further drawback with the use of incandescent lamps in wayside signals is that incandescent lamps are relatively energy inefficient. 
     Accordingly, a need exists for an improved means for providing wayside signals for use with railways. 
     SUMMARY OF THE INVENTION 
     These needs and others are met by embodiments of the invention, which are directed to an improved light assembly. The light assembly comprises a lighting module having a number of LEDs, a reflector assembly disposed on the lighting module, a lens member disposed over the reflector assembly and coupled to the lighting module, and a membrane disposed between the reflector member and the lens. The reflector assembly includes a number of individual reflector portions, each reflector portion being of generally concave shape and structured to selectively direct light emitted from a respective one of the number of LEDs. 
     The membrane may comprise a nylon screen material. The membrane may comprise a phankill screen. The lighting module may comprise a plurality of LEDs and the reflector assembly may comprise a plurality of reflector portions, each reflector portion being disposed about a corresponding one of the plurality of LEDs. The plurality of reflector portions may comprise a first number of reflector portions, each reflector portion of the first number of reflector portions being structured to generally direct light emitted from a corresponding LED a first distance from the light assembly. The plurality of reflector portions may comprises a second number of reflector portions, each reflector portion of the second number of reflector portions being structured to generally direct light emitted from a corresponding LED a second distance from the light assembly, wherein the first distance is greater than the second distance. The first number of reflector portions may be disposed in a first pattern and the second number of reflector portions may are disposed in a second pattern generally around the first pattern. The plurality of reflectors may comprise a first number of reflector portions disposed in a first pattern and a second number of reflector portions disposed in a second pattern generally around the first pattern. Each reflector portion of the first number of reflector portions may be structured to direct light emitted from a corresponding LED a first distance from the light assembly and each reflector portion of the second number of reflector portions may be structured to direct light emitted from a corresponding LED a second distance greater than the first distance. The number of individual reflector portions may be structured to selectively direct light in an AREMA specified pattern. The first number of reflector portions may comprise four reflector portions and the second number of reflector portions may comprise ten reflector portions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full understanding of the disclosed concept can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which: 
         FIG. 1  is an isometric view of a light assembly in accordance with an embodiment of the invention. 
         FIG. 2  is an exploded view of the light assembly of  FIG. 1 . 
         FIG. 3  is a front elevation view of the light assembly of  FIG. 1 . 
         FIG. 4  is a cross-sectional view of the light assembly taken along line  4 - 4  of  FIG. 3 . 
         FIG. 5  is a front elevation view of the reflector of  FIGS. 1-4 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As employed herein, the statement that two or more parts are “connected” or “coupled” together shall mean that the parts are joined together either directly or joined through one or more intermediate parts. Further, as employed herein, the statement that two or more parts are “attached” shall mean that the parts are joined together directly. 
       FIG. 1  shows a light assembly  10  in accordance with an embodiment of the invention. Light assembly  10  may be commonly mounted on a pole or other structure (not shown) generally at or about a section of railway such as to be readily viewed by a train approaching on the adjacent railway. 
     As shown in the exploded view of  FIG. 2  and the cross-sectional view of  FIG. 4 , light assembly  10  includes a base portion  12  a reflector assembly  14  coupled thereto, a screen member  16  disposed generally over the reflector portion, and a lens member  18  disposed over the screen member  16  and reflector portion  14  and coupled to the base portion  12 . 
     Continuing to refer to  FIG. 2 , base portion  12  generally includes a housing portion  20  with a light emitting member  22  disposed therein. In the depicted embodiment, light emitting member  22  comprises a printed circuit board  24  having a number of light emitting diodes  26  (LED&#39;s) disposed thereon. As employed herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality). One or more heatsinks  28  may be coupled to or near printed circuit board  24  in order to help direct away and dissipate heat from the LED&#39;s  26 . 
     Reflector assembly  14  is preferably formed from a plastic having a reflective coating or other suitable material that may readily have one or more individual reflectors formed therein. Although shown as a single unitary member, it is to be appreciated that reflector assembly  14  may be formed from a number of separate elements assembled together or in multiple elements without varying from the scope of the present invention. Referring to  FIGS. 4 and 5 , reflector assembly  14  includes a number of apertures  30  which are each sized to accept an LED  26  therein when reflector assembly  14  is coupled to base portion  12  over printed circuit board  24 , as perhaps best shown in the cross sectional view of  FIG. 4 . Reflector assembly  14  further includes a number of generally concave shaped individual reflector portions  32  generally disposed around each of the apertures  30 . Each of reflector portions  32  is of suitable shape to reflect/project light produced by an LED  26  (disposed in the associated aperture  30 ) a distance outward from the light assembly  10 . In a particular light assembly, all of the individual reflector portions  32  may be of similar design and thus reflect light in a similar manner, alternatively, the reflector portions  32  may be of multiple designs and thus may reflect light produced by the associated LED&#39;s in different manners. 
     For example, in the embodiment depicted in the Figs., two different reflector designs are utilized. A first number of reflectors  34  of a first design are arranged in a generally circular arrangement (pattern) near a central portion of reflector assembly  14 . A second number of reflectors  36  of a second design are arranged in another arrangement generally around the first number of reflectors  34 . In such embodiment, each reflector  34  of the first number of reflectors is designed to project light a greater from the light assembly  10  than each reflector  36  of the second number of reflectors. Such general arrangement provides for an overall light emission that is visible from far distances but yet full from closer distances. By selectively arranging reflectors of different designs the light signal projected by the light assembly  10  can be tailored to produce specific desired outputs. For example, the example light assembly depicted in the Figs. is arranged to produce a light signal projected according to an AREMA (American Railway Engineering and Maintenance-of-Way Association) specification which may be arranged as a matrix of angles in the x and y directions with specific candlepower in each location. 
     As shown in the cross-sectional view of light assembly  10  in  FIG. 4 , screen  16  is generally disposed across all or substantially all of reflector assembly  14 . Screen member  16  is preferably formed from a flat black nylon screen or other suitable material. When light assembly  10  is in use, screen member  16  generally functions as an antiphantom (i.e., phankill) mechanism that acts to reduce the appearance of false illumination of light assembly  10  due to light from sources of light external to light assembly  10  (e.g., without limitation sunlight) striking reflector assembly  14 . In order to further prevent false illumination signals, flat surfaces of the reflector assembly  14 , such as those between reflectors  32 , are preferably colored black or another suitable dark, non reflective color. 
     Continuing to refer to the cross-sectional view of  FIG. 4 , lens member  18  is preferably formed from a clear plastic or other suitable material (e.g., without limitation, polished aluminized plastic) and is of a generally concave shape formed to generally enclose reflector assembly  14  therein when lens member  18  is coupled to base portion  12 . Preferably such coupling is of a type that allows for lens member  18  to be selectively uncoupled from base portion  12  in order to allow for maintenance of the light assembly  10 . Furthermore, such coupling preferably provides for the contents of light assembly  10  to be generally sealed in order to prevent the ingress of water or other unwanted environmental elements. 
     While specific embodiments of the disclosed concept have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof.