Abstract:
A light fixture comprising a mounting housing comprising a junction box and a first connector component and a light housing comprising at least one light emitting diode contained within the light housing and electrically coupled to a second connector component complementary to the first connector component.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to lighting fixtures. In particular, this invention relates to a mounted LED light fixture. 
       BACKGROUND OF THE INVENTION 
       [0002]    Lighting fixtures are used in many different applications. Indoor mounted lights in particular are used for different purposes, including ambient lighting, decorative lighting and lighting for specific work areas, often known as “task lighting.” These different types of lighting have different requirements. 
         [0003]    In addition, there are different types of light sources, including incandescent, fluorescent, and more recently, light emitting diodes (LEDs). These different types of light sources are advantageously used in different applications. Within each different type of light source there are also different colours of light, often referred to as the “colour temperature” of the light source. Thus, lighting for any particular purpose can be selected based on the type of light fixture and light source which is most suitable for the application. 
         [0004]    LED lighting has certain advantages. LED lights consume significantly less electricity than incandescent lights, up to 80% less in some cases. Furthermore, LEDs are more durable, lasting fifty thousand to one hundred thousand hours as opposed to twenty thousand hours for average incandescent lighting. This makes LED lighting particularly suitable for certain applications were a high degree of illumination is required. 
         [0005]    However, commensurate with the high level of illumination is a significant amount of heat which must be dissipated from the fixture. Furthermore, in certain applications where the light fixture is to be mounted into a surface which is not accessible, the light fixture must be completely self-contained including all connections to the electrical wiring, within a housing that meets all regulatory requirements. Furthermore, such a light fixture may need to be maintained or replaced and therefore access to the interior of the light fixture must be relatively easy and safe. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    In drawings which illustrate by way of example only a preferred embodiment of the invention, 
           [0007]      FIG. 1  is a perspective view of a light fixture according to the invention in an assembled state; 
           [0008]      FIG. 2  is a partially exploded perspective view of the light fixture of  FIG. 1 ; 
           [0009]      FIG. 3  is a perspective view of the light fixture of  FIG. 1  taken from behind a panel in which the fixture is mounted; 
           [0010]      FIG. 4  is a partially exploded perspective view of the light fixture being mounted in the panel of  FIG. 3 ; 
           [0011]      FIG. 5  is a side elevation of the light fixture mounted in the panel of  FIG. 3 ; 
           [0012]      FIG. 6  is a rear perspective view of the mounting portion of the housing; 
           [0013]      FIG. 7  is a partially exploded perspective view of the mounting portion of the housing taken from below; 
           [0014]      FIG. 8  is a top plan view of a lighting portion of the housing; 
           [0015]      FIG. 9  is a side elevation of the lighting portion of the housing in  FIG. 8 ; 
           [0016]      FIG. 10  is a bottom plan view of the lighting portion of the housing in  FIG. 8 ; 
           [0017]      FIG. 10A  is a bottom plan view of a further embodiment of the lighting portion of the housing without lens retaining clips; 
           [0018]      FIG. 11  is an exploded perspective view of the lighting portion of the housing in  FIGS. 8 ; and 
           [0019]      FIG. 12  is a bottom plan view of lighting emitters mounted to a circuit board in the lighting portion of the housing in  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    The present invention provides a high-illumination LED lighting fixture  10  for recessed mounting. The lighting fixture  10  of the invention is particularly suitable for use as task lighting in applications which require high illumination and particularly in applications where the light fixture  10  might be exposed to extremes in temperature and/or humidity, for example for lighting within a fume hood above a commercial cook top where heat and steam may be present for prolonged intervals. 
         [0021]    A lighting fixture according to the invention is illustrated in  FIG. 1 . Lighting fixture  10  comprises two main housing components: a mounting housing  20  and a lighting housing  40 , as illustrated in  FIG. 2 . When the fixture  10  is mounted into a surface, for example a panel  2 , the mounting housing  20  of the fixture  10  is recessed behind the surface, as illustrated in  FIG. 3 . As shown in  FIG. 4 , the mounting housing  20  maybe mounted to the panel  2  prior to installation of the panel, for example by affixing nuts  22  to bolts  24  upstanding from the mounting housing flange  26 . The mounted fixture  10  is shown in  FIG. 5 . 
         [0022]    The mounting housing  20 , best seen in  FIG. 6 , comprises a flange  26  circumscribing a lower portion of the housing  20 , and preferably providing upstanding bolts  24  for purposes of mounting the fixture  10  as described above. The flange  26  further includes embedded nuts  28  for receiving screws  42   a  (see  FIG. 4 ) for attaching the lighting housing  40  to the mounding housing  20 . As shown in  FIG. 6 , the mounting housing  20  further includes a junction box  30  having at least one opening  32  for receiving conductors from a mains power supply (not shown) and a junction box cap plate  34  (seen in  FIG. 4 ). The junction box cap plate  34  comprises terminals  34   a  for coupling the mains power supply conductors (not shown) to the male or female side of a press fit connector  36  mounted within the junction box  30  (best seen in  FIG. 7 ). The exterior of the mounting housing  20  is provided with generally radially extending fins  38  substantially circumscribing the junction box  30 , to allow for heat dissipation behind the mounting surface  2 . An elastomeric (for example silicon) gasket  39  seals the flange against the panel  2  when the lighting fixture  10  is mounted. The mounting housing is preferably formed from cast aluminium, or another material designed to meet regulatory requirements and allow for effective heat dissipation. 
         [0023]    The light housing  40  is illustrated in  FIGS. 8 to 11 . The light housing  40  comprises a flange  42  complementary to the flange  26  of the mounting housing  20  and having openings  44  adapted to align with the recessed nuts  28  in the mounting housing flange  26 . Mounted on the top surface  46  of the light housing  40  is the other male or female portion of the connector  36 , for press fit connection to the complementary portion of the connector  36  mounted into the junction box  30 . The flange  42  surrounds a recess  48  within which is mounted the emitter board  60  and a glass lens  70 , as shown in  FIG. 11 . The emitter board  60 , shown in  FIG. 12 , maybe a standard LED circuit board, designed to withstand the high temperatures generated by prolonged use of the LEDs  62  in the operation of the light fixture  10 . The LEDs  62  are preferably arranged generally symmetrically around the emitter board  60 , providing for a generally even distribution of heat and light when the light fixture  10  is active. The emitter board  60  fits into the recess  48  and is retained by the wires grommet  54  and Epoxy material (not shown) and the glass lens  70 , which is in turn retained by lens retaining clips  50  if used and the Epoxy potting material. The glass lens  70  is preferably a diffusing lens, and is formed from tempered glass capable of withstanding the high heat generated by the LEDs  62  and with suitable impact resistance to meet regulatory requirements. 
         [0024]    The emitter board  60  is assembled to the light housing  40  by placing the emitter board  60  within the recess  48  and coupling the ends of the circuit tracks (not shown) to the portion of the connector  36  mounted to the top surface of the light housing  40  via suitable conductors (not shown) extending through opening  54 ,  64  in the light housing  40  and emitter board  60 , respectively. The glass lens  70  is placed over the emitter board  60  and embedded in the potting Epoxy material (not shown) in which the potting material after curing will secure, seal and retain the glass lens  70 . In the final assembly of the lighting fixture  10 , which comprises the mounting housing  20  and lighting housing  40 , the lens retaining clips  50  are swivelled into place and tightened to retain lens in position. The clips  50  are optional and may be omitted, as in the embodiment of  FIG. 10A . 
         [0025]    The mounting housing  20  is inserted into a suitable opening in the panel  2  and affixed (for example by attaching nuts  22  to upstanding bolts  24 ). The main power supply conductors (not shown) are introduced into the junction box  30  through opening  32  and retained by a suitable wire clamp. Terminals  34   a  may be used to connect the mains power supply conductors to the portion of the connector  36  mounted into the junction box  30 , and the panel  2  is mounted to the surface (for example, inside a fume hood above a cook surface). The light housing  40  is mounted to the mounting housing  20  by properly aligning the openings  44  in the flange  42  with the nuts  28  in the flange  26 , at which point the connector portion  36  attached to the light housing  40  is properly aligned with the complementary portion of the connector  36  mounted inside the junction box  30 . The light housing  40  is pressed into the mounting housing  20  so that the complementary portions of the connector  36  are attached in press fit relation, and screws  42   a  are threaded into the nuts  28  to maintain the light housing  40  in place. 
         [0026]    Thereafter, if servicing is required the screws  42   a  can be removed and the light housing  40  pulled off of the mounting housing  20 , allowing access to all wiring connections within the junction box  30 . This facilitates maintenance of the light fixture  10 , and changing of the complete lighting housing  40  or the emitter board  60  when required. 
         [0027]    Preferably once the emitter board  60  has been soldered to the conductors (not shown) for coupling to the connector portion  36  mounted to the light housing  40 , a potting compound such as epoxy is poured into the recess  48  over the emitter board  60  and the lens  70  is affixed in place before the potting compound (not shown) hardens. The potting compound encapsulates the emitter board  60  and seals the lens  70  into the recess  48 , thus protecting the emitter board  60  and soldered connections from environmental influences such as temperature and humidity. This is particularly advantageous in an application such as a fume hood disposed above a cook top, where high temperature and humidity conditions generally prevail during use. At the same time, when the light fixture  10  is in use, heat is dissipated by the fins  38  into the fume hood, thus allowing the light fixture  10  to operate at acceptable temperatures. 
         [0028]    To ensure an air tight seal after tightening of the  4  screws  72  between the two parts of final assembly of the lighting fixture  10 , which comprises the mounting housing  20  and lighting housing  40 , an elastomeric (for example silicon) gasket  71  is placed over flange  42  and trapped between flange  42  and flange  26  when the lighting housing  40  is affixed to the mounting housing  20 . 
         [0029]    The invention has been described in the context of a particular application, however its implementation is not so limited. The light fixture  10  of the invention may be used in other mounted applications. 
         [0030]    Various embodiments of the present invention having been thus described in detail by way of example, it will be apparent to those skilled in the art that variations and modifications may be made without departing from the invention.