Patent Publication Number: US-6991348-B2

Title: Light cover with double railed sealing edge

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a light cover, such as a prismatic lens, particularly for fluorescent or similar lights, which uses a double rail configuration on the edges to provide an improved watertight seal, particularly for use in car washes or other similar wet environments. 
   2. Description of the Prior Art 
   In the prior art, light covers, such as prismatic lenses, which require a relatively waterproof seal are known. However, in some particularly wet environments, such as car washes, improvements in the watertight sealing, while retaining a simple assembly and disassembly process, are desired. 
   OBJECTS AND SUMMARY OF THE INVENTION 
   It is therefore an object of the present invention to provide a light cover, such as a prismatic lens, with an improved watertight seal for use in particularly wet applications. 
   It is therefore a still further object of the present invention to provide a light cover, such as a prismatic lens, with an improved watertight seal, which retains a simple assembly and disassembly process. 
   It is therefore a still further object of the present invention to provide a light cover, such as a prismatic lens, which achieves the above objects with little or no increase in cost or manufacturing complexity. 
   These and other objects are attained by providing a light cover, such as a prismatic lens, which has a generally planar surface with walls extending from the periphery of the planar surface and terminating in an out-turned lip, wherein the periphery of the out-turned lip defines an open end which is secured to an upper half of a light fixture, a ceiling or similar architectural structure with a sealing or washer-like material between the lip and the upper half of the light fixture, the ceiling or similar architectural structure. The apex of the out-turned lip includes two ridges or rails which are generally parallel to each other or spaced apart from each other and extend around the apex of the out-turned lip. An interstice is formed between the two rails. When clips or similar devices engage the out-turned lip so as to secure the light cover to the upper half of the light fixture, the ceiling or similar architectural structure with the sealing or washer-like material therebetween, the two ridges or rails are oriented so as to be urged against the sealing or washer-like material thereby urging the sealing or washer-like material into the interstice and forming an improved watertight seal. The resulting structure requires no change to the clips or similar devices which are used to secure the light cover to the upper half of the light fixture, the ceiling or similar architectural structure, and requires little or no change to the sealing or washer-like material between the upper half of the light fixture or the ceiling and the light cover. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein: 
       FIG. 1  is a fragmented plan view of the bottom exterior of the lighting cover of the present invention. 
       FIG. 2  is a cross-sectional view along plane  2 — 2  of  FIG. 1 . 
       FIG. 3  is a cross-sectional view along plane  3 — 3  of  FIG. 1 . 
       FIG. 4  is a cross-sectional view along plane  4 — 4  of  FIG. 1 . 
       FIG. 5  is a cross-sectional view of the lighting cover of the present invention. 
       FIG. 6  is a detailed cross-sectional view of a portion of  FIG. 5 , showing a fluorescent bulb in phantom and further showing the detail of the double rail system, particularly with respect to the sealing or washer-like material used during installation. 
       FIG. 7  is a perspective view of a light cover of the present invention, shown in an installed configuration or orientation, with an illustrative set of proportions. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the drawings in detail wherein like numerals indicate like elements throughout the several views,  FIG. 1  is a fragmented plan view of the bottom exterior of the lighting cover  10  of the present invention.  FIGS. 2–6  show various cross-sectional views while  FIG. 7  shows an illustrative set of proportions for the lighting cover  10 . 
   Lighting cover  10  is typically made from clear polycarbonate F 1  rated for UV protection or clear acrylic with a 15% DR content. However, those skilled in the art, after review of this disclosure, will recognize that a range of materials may be substituted for these materials. 
   Lighting cover  10  includes a generally rectangular planar floor  12 . A cartesian-like array of prismatic elements  14  with tapered sides and an elongated peak is formed on the upper or interior side of planar floor  12 . The prismatic elements  14  serve to disperse the light from a bulb  200  (shown in phantom in  FIG. 6 ), typically a fluorescent bulb, which is ultimately enclosed within the light cover  10  in the installed orientation or configuration shown in  FIG. 7 . Planar floor  12  is bounded by end portions  16 ,  20  and side portions  18 ,  22 . Curved walls  24 ,  26 ,  28 ,  30  arise from portions  16 ,  18 ,  20 ,  22 , respectively. The interior surfaces of curved walls  24 ,  26 ,  28 ,  30  similarly include interior prismatic faces  32  to diffuse and disperse the light from a bulb  200  (shown in phantom in  FIG. 5 ) enclosed therewith. Curved walls  24 ,  26 ,  28 ,  30  terminate in outwardly flared flange-type lips  34 ,  36 ,  38 ,  40  respectively, which form the generally rectangular upper periphery which is urged against a sealing or washer-like material  100  (see  FIG. 6 ) in the installed configuration. 
   As shown in  FIGS. 2–6 , the uppermost portion of outwardly flared flanged-type lips  34 ,  36 ,  38 ,  40  includes two rails  42 ,  44  which are spaced apart and extend continuously around the generally rectangular upper periphery formed by outwardly flared flanged-type lips  32 ,  34 ,  36 ,  38 . Interstice  46  is formed between rails  42 ,  44  and likewise extends about the generally rectangular upper periphery. 
   As shown in  FIG. 6 , in the installed configuration, outwardly flared lips  34 ,  36 ,  38 ,  40  and particularly rails  42 ,  44  are urged against sealing or washer-like material  100 . Clips or similar hardware (not shown) are used to engage outwardly flared flanged-type lips  34 ,  36 ,  38 ,  40  to the upper half of the light fixture, the ceiling or similar architectural structure (not shown). As rails  42 ,  44  are urged against the sealing or washer-like material  100 , a portion of the sealing or washer-like material  100  is urged into interstice  46 . This portion of material  100  urged into interstice  46  causes a serpentine interface between lighting cover  10  and material  100  to be formed thereby greatly increasing its watertight characteristics. 
   Thus the several aforementioned objects and advantages are most effectively attained. Although preferred embodiments of the invention have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.