Abstract:
A light fixture comprising a chamber, at least one power-circuitry driver within the chamber, at least one LED module outside the chamber, and at least one air gap between the chamber and the at least one LED module, the air gap permitting air/water-flow therethrough. The chamber is defined by a housing. The at least one LED module is on an LED heat sink outside the chamber. The housing defines the air gap permitting air/water-flow to and from the heat sink.

Description:
RELATED APPLICATION 
       [0001]    This application is a continuation of patent application Ser. No. 13/834,525, filed Mar. 15, 2013, which is a continuation of patent application Ser. No. 13/294,459, filed Nov. 11, 2011, now Pat. No. 8,425,071, issued Apr. 23, 2013, which is a continuation of patent application Ser. No. 12/629,986, filed Dec. 3, 2009, now Pat. No. 8,070,306, issued Dec. 6, 2011, which is a continuation of patent application Ser. No. 11/860,887, filed Sep. 25, 2007, now Pat. No. 7,686,469, issued Mar. 30, 2010, which is a continuation-in-part of now abandoned patent application Ser. No. 11/541,908, filed Sep. 30, 2006. The entire contents of each of the parent applications are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to lighting fixtures and, more particularly, to lighting fixtures using light-emitting diodes (LEDs). 
       BACKGROUND OF THE INVENTION 
       [0003]    In recent years, the use of LEDs for various common lighting purposes has increased, and this trend has accelerated as advances have been made in LEDs and in LED arrays, often referred to as “LED modules.” Indeed, lighting applications which previously had been served by fixtures using what are known as high-intensity discharge (HID) lamps are now beginning to be served by fixtures using LEDs. Such lighting applications include, among a good many others, roadway lighting, factory lighting, parking lot lighting, and commercial building lighting. 
         [0004]    Lighting fixtures using LEDs as light source for various applications present particularly challenging problems in fixture development, particularly when fixture mounting locations vary. Among other things, placement of the electronic LED power units (LED drivers) for lighting fixtures using LED arrays can be particularly problematic. In some cases, keeping such electronic LED drivers in a air/water-tight location may not be difficult, but if mounting locations and structures vary, then location and protection of such components becomes difficult and adds development costs and potential problems. Lighting-fixture adaptability is an important goal for LED lighting fixtures that are often presented. 
         [0005]    Heat dissipation is another problem for LED lighting fixtures. And, the goals of dealing with heat dissipation and protection of electronic LED drivers can often be conflicting, contrary goals. 
         [0006]    In short, there is a significant need in the lighting industry for improved lighting fixtures using LED units—fixtures that are adaptable for a wide variety of mountings and situations, and that satisfy the problems associated with heat dissipation and appropriate protection of electronic LED driver components. Finally, there is a need for an improved LED-based lighting fixture which is easy and inexpensive to manufacture. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is an improvement in LED lighting fixtures. The inventive LED lighting fixture includes a housing forming a substantially air/water-tight chamber, at least one electronic LED driver enclosed within the chamber, and an LED assembly secured with respect to the housing adjacent thereto in non-air/water-tight condition, the LED assembly having at least one LED-array module mounted on an LED heat sink. 
         [0008]    The housing preferably includes substantially air/water-tight wire-access(es) for passage of wires between the LED assembly and the air/water-tight chamber. 
         [0009]    The housing includes a first border structure forming a first border-portion of the chamber, the first border structure receiving wires from the at least one LED-array module and the LED heat sink being interlocked with the first border structure. The housing further includes a frame structure forming a frame-portion of the chamber secured to the first border structure, the frame structure extending along the LED assembly. It is preferred that the border structure be a metal extrusion. 
         [0010]    In some preferred embodiments, the first border structure has at least one bolt-receiving border-hole through the first border structure, such border-hole being isolated from the first border-portion of the chamber. The frame structure also has at least one bolt-receiving frame-hole through the frame structure, the frame-hole being isolated from the frame-portion of the chamber. Each such one or more frame-holes are aligned with a respective border-hole(s). A bolt passes through each aligned pair of bolt-receiving holes such that the border structures and the frame structure are bolted together while maintaining the air/water-tight condition of the chamber. 
         [0011]    In some highly preferred embodiments, the housing includes a second border structure forming a second border-portion of the chamber, the LED heat sink being interlocked with the second border structure. In such embodiments, the frame structure is secured to the first and second border structures. 
         [0012]    The frame structure preferably includes an opening edge about the frame-portion of the chamber. A removable cover-plate is preferably in substantial water/air-tight sealing engagement with respect to the opening edge. Such opening edge may also have a groove configured for mating air/water-tight engagement with the border structure(s). It is preferred that one or more electronic LED drivers be enclosed in the frame-portion of the chamber. 
         [0013]    In certain preferred embodiments the frame structure preferably includes a vent permitting air flow to and from the LED assembly. Such venting facilitates cooling of the LED assembly. 
         [0014]    In certain highly preferred embodiments of this invention, including those used for street lighting and the like, the housing is a perimetrical structure such that the substantially air/water-tight chamber substantially surrounds the LED assembly. The perimetrical structure is preferably substantially rectangular and includes the first and second border structures and a pair of opposed frame structures each secured to the first and second border structures. 
         [0015]    In some versions of the inventive LED lighting fixture, the housing is a perimetrical structure configured for wall mounting and includes the first and second border structures on opposed perimetrical sides and the frame structure secured on a perimetrical side between the border structures. 
         [0016]    In such embodiments, each of the first and second border structures preferably has at least one bolt-receiving border-hole therethrough isolated from the first and second border-portion of the chamber, respectively. Each of the frame structures has at least one bolt-receiving frame-hole therethrough isolated from the frame-portion of the chamber, each such frame-holes aligned with respective border-holes of each of the border structures. A bolt is passing through each aligned set of bolt-receiving holes such that the border structures and the frame structures are bolted together while maintaining the air/water-tight condition of the chamber. 
         [0017]    In certain highly preferred embodiments of the inventive LED lighting fixture, the LED assembly includes a plurality of LED-array modules each separately mounted on its corresponding LED heat sink, the LED heat sinks being interconnected to hold the LED-array modules in fixed relative positions. Each heat sink preferably includes a base with a back base-surface, an opposite base-surface, two base-ends and first and second base-sides. A female side-fin and a male side-fin each extends along one of the opposite base-sides and each protrudes from the opposite base-surface to terminate at a distal fin-edge. The female side-fin includes a flange hook positioned to engage the distal fin-edge of the male side-fin of an adjacent heat sink At least one inner-fin projects from the opposite surface between the side-fins. One of the LED modules is against the back surface. 
         [0018]    In some preferred embodiments, each heat sink includes a plurality of inner-fins protruding from the opposite base-surface. Each heat sink may also include first and second lateral supports protruding from the back base-surface, the lateral supports each having an inner portion and an outer portion. The inner portions of the first and second lateral supports have first and second opposed support-ledges, respectively, forming a heat-sink-passageway slidably supporting one of the LED-array modules against the back base-surface. The first and second supports of each heat sink are preferably in substantially planar alignment with the first and second side-fins, respectively. The flange hook is preferably at the distal fin-edge of the first side-fin. 
         [0019]    It is highly preferred that each heat sink be a metal extrusion with the back base-surface being substantially flat to facilitate heat transfer from the LED-array module, which itself has a flat surface against the back-base surface. 
         [0020]    Each heat sink also preferably includes a lateral recess at the first base-side and a lateral protrusion at the second base-side, the recesses and protrusions being positioned and configured for mating engagement of the protrusion of one heat sink with the recess of the adjacent heat sink. 
         [0021]    In certain of the above preferred embodiments, the female and male side-fins are each a continuous wall extending along the first and second base-sides, respectively. It is further preferred that the inner-fins are also each a continuous wall extending along the base. The inner-fins can be substantially parallel to the side-fins. 
         [0022]    In highly preferred embodiments, the LED lighting fixture further includes an interlock of the housing to the LED assembly. The interlock has a slotted cavity extending along the housing and a cavity-engaging coupler which extends from the heat sink of the LED assembly and is received within the slotted cavity. 
         [0023]    In some of such preferred embodiments, in each heat sink, at least one of the inner-fins is a middle-fin including a fin-end forming a mounting hole receiving a coupler. In some versions of such embodiments, the coupler has a coupler-head; and the interlock is a slotted cavity engaging the coupler-head within the slotted cavity. The slotted cavity preferably extends along the border structure and the coupler-head extends from the heat sink of the LED assembly. 
         [0024]    In preferred embodiments of this invention, the LED lighting fixture includes a restraining bracket secured to the housing. The bracket has a plurality of projections extending between adjacent pairs of fins of the heat sink, thus to secure the LED assembly. The restraining bracket preferably has a comb-like structure including an elongated body with a spine-portion from which identical side-by-side projections extend in a common plane. Such restraining bracket is configured and dimensioned for the elongated body to be fixedly secured to the housing and the projections to snugly fit in spaces between adjacent heat-sink fins, thus holding heat sink from moving. 
         [0025]    The LED lighting fixture further includes a mounting assembly secured to the housing. The mounting assembly preferably has a pole-attachment portion and a substantially air/water-tight section enclosing electrical connections with at least one wire-aperture communicating with the air/water-tight chamber. The housing is in air/water-tight engagement with the air/water-tight section of the pole-mounting assembly. 
         [0026]    In the aforementioned substantially rectangular versions of this invention, in which the perimetrical structure includes a pair of opposed frame structures and a first and second opposed border structures, the second border structure may have two sub-portions with a gap therebetween. The sub-portions each include all of the border-structure elements. 
         [0027]    In the mounting assembly of such embodiments, the pole-attachment portion preferably receives and secures a pole. Each wire-aperture communicates with the border-portion chamber of a respective one of the second border-structure sub-portions. The gap between the second border-structure sub-portions accommodates the pole-mounting assembly secured to the LED assembly between the border sub-portions. The second border-structure sub-portion(s) are in air/water-tight engagement with the air/water-tight section of the pole-mounting assembly. The pole-attachment portion preferably includes grooves on its opposite sides, the grooves being configured for mating engagement with end edges of the border-structure sub-portions. 
         [0028]    Preferably, the pole-mounting assembly has a mounting plate abutting the LED assembly, and at least one fastener/coupler extends from the mounting plate for engagement with the mounting hole of the middle-fin(s). 
         [0029]    In some LED lighting fixtures of this invention, the frame-portion of the chamber has a chamber-divider across the chamber, such chamber-divider having a divider-edge. The chamber-divider divides the frame-portion of the chamber into an end part and a main part that encloses the electronic LED driver(s). The chamber-divider preferably includes a substantially air/water-tight wire-passage therethrough. The wire-passage is preferably a notch having spaced notch-wall ends that terminate at the divider-edge. A notch-bridge spans the notch to maintain the air/water-tight condition of the chamber. The notch-bridge preferably includes a bridge-portion and a pair of gripping-portions configured for spring-grip attachment to the notch-wall ends. Preferably, the removable cover-plate seals the main part of the frame-portion of the chamber in substantially air/water-tight condition. 
         [0030]    In certain embodiments of this invention, including those used for parking-structure lighting and the like, the frame structure is a sole frame structure, and the housing is a substantially H-shaped structure with the sole frame structure secured between mid-length positions of the pair of opposed border structures. 
         [0031]    Some of the inventive LED lighting fixtures include a protective cover extending over the LED assembly and secured with respect to the housing. Such protective cover preferably has perforations permitting air/water-flow therethrough for access to and from the LED assembly. 
         [0032]    It is most highly preferred that the LED lighting fixture has a venting gap between the housing and the LED assembly to permit air/water-flow from the heat sink The venting gap may be formed by the interlock of the housing to the LED assembly. 
         [0033]    The improved LED lighting fixture of this invention overcomes the problems discussed above. Among other things, the invention provides substantially air/water-tight enclosure of electronic LED drivers inside the fixture, while still accommodating heat-dissipation requirements. And, the fixture of this invention is both adaptable for varying applications and mountings, and relatively inexpensive to manufacture. 
         [0034]    The term “perimetrical structure” as used herein means an outer portion of the fixture which completely or partially surrounds remaining portions of the fixture. In certain preferred embodiments, such as those most useful for road-way lighting and the like, the perimetrical structure preferably completely surrounds remaining portions of the fixture. In certain other cases, such as certain wall-mounted lighting fixtures, the perimetrical structure partially surrounds the remaining portions of the fixture. 
         [0035]    The term “ambient fluid” as used herein means air and/or water surrounding the lighting fixture. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0036]      FIG. 1  is a perspective view of a preferred LED lighting fixture in accordance with this invention, including a cut-away portion showing an LED assembly. 
           [0037]      FIG. 2  is a perspective view of the LED lighting fixture configured for wall mounting. 
           [0038]      FIG. 3  is a perspective view of another LED lighting fixture including a pole-mounting assembly on a pole of square cross-section. 
           [0039]      FIG. 4  is a side perspective view of the LED lighting of  FIG. 1  broken away at a middle portion to show interior structure. 
           [0040]      FIG. 5  is a front perspective view of the LED lighting of  FIG. 1  broken away at a middle portion to show interior structure. 
           [0041]      FIG. 6  is a fragmentary view of the right portion of  FIG. 4 . 
           [0042]      FIG. 7  is another fragmentary perspective view showing the frame structure partially cut-away view to illustrate its being bolted together with the border structure. 
           [0043]      FIG. 8  is another fragmentary perspective view showing the border structure partially cut-away view to illustrate its engagement with the frame structure. 
           [0044]      FIG. 9  is a greatly enlarged fragmentary perspective view showing a portion of the chamber-divider wall, the notch therein and the notch-bridge thereover. 
           [0045]      FIG. 10  is a perspective view of one LED-array module LED and its related LED heat sink of the LED assembly of the illustrated LED lighting fixtures. 
           [0046]      FIG. 11  is a perspective view of two interconnected LED heat sinks of the LED assembly of the illustrated LED lighting fixtures. 
           [0047]      FIG. 12  is a fragmentary perspective view from below of the pole-mounting assembly engaged with a pole-attachment portion, with the cover of the pole-mounting assembly removed to show internal parts. 
           [0048]      FIG. 13  is a perspective view of the LED lighting fixture of the type having the housing being a substantially H-shaped structure. 
           [0049]      FIG. 14  is a top perspective view of another embodiment of the LED lighting fixture including a restraining bracket seen through a cut-away in the protective cover. 
           [0050]      FIG. 15  is a perspective view of the restraining bracket of  FIG. 14 . 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0051]      FIGS. 1-15  illustrate preferred LED lighting fixtures  10 A- 10 D in accordance with this invention. Common or similar parts are given the same numbers in the drawings of both embodiments, and the lighting fixtures are often referred to by the numeral  10 , without the A or D lettering used in the drawings, and in the singular for convenience. 
         [0052]    Lighting fixture  10  includes a housing  12  that forms a substantially air/water-tight chamber  14 , at least one electronic LED driver  16  enclosed within chamber  14  and an LED assembly  18  secured with respect to housing  12  adjacent thereto in non-air/water-tight condition. LED assembly  18  has a plurality of LED-array modules  19  each secured to an LED heat sink  20 . 
         [0053]    As seen in  FIGS. 1-4 ,  7  and  8 , housing  12  includes a frame structure  30  forming a frame-portion  32  of chamber  14  with an opening edge  34  thereabout and a border structure  40  (sometimes referred to as a nose structure  40 ) secured to frame structure  30  and forming a border-portion  42  (sometimes referred to as nose-portion  42 ) of chamber  14 . As best seen in  FIG. 8 , opening edge  34  of frame-portion  30  of chamber  14  includes a groove  35  configured for mating air/water-tight engagement with border structure  40 . Border structure  40  is an extrusion, preferably of aluminum.  FIG. 5  shows electronic LED drivers  16  enclosed in frame-portion  32  of chamber  14 . 
         [0054]    As best seen in  FIG. 6 , border structure  40  includes substantially air/water-tight wire-accesses  44  for passage of wires  17  between LED assembly  18  and water/air-tight chamber  14 . 
         [0055]      FIGS. 2 ,  3 ,  5  and  7  show that frame structure  30  includes a vent  36  permitting air flow to and from LED assembly  18 . Vent  36  facilitates cooling of LED assembly  18 . 
         [0056]    As best illustrated in  FIGS. 6 and 7 , border structure  40  has bolt-receiving border-hole  47  therethrough which is isolated from border-portion  42  of chamber  14 . And, frame structure  30  has bolt-receiving frame-holes  37  therethrough which are isolated from frame-portion  32  of chamber  14 ; frame-hole  37  is aligned with a respective border-hole  47 . A bolt  13  passes through aligned pair of bolt-receiving holes  37  and  47  such that border structure  40  and frame structure  30  are bolted together while maintaining the air/water-tight condition of chamber  14 . 
         [0057]      FIGS. 1 and 3  best illustrate certain highly preferred embodiments of this invention in which housing  12  is a perimetrical structure which includes a pair of opposed frame structures  30  and a pair of opposed nose structures  40 , making perimetrical structure  12  of lighting fixture  10 A substantially rectangular.  FIGS. 1 ,  4 - 8  and  11  illustrate aspects of inventive LED lighting fixture  10 A. 
         [0058]    In LED lighting fixtures  10 , LED assembly  18  includes a plurality of LED-array modules  19  each separately mounted on its corresponding LED heat sink  20 , such LED heat sinks  20  being interconnected to hold LED-array modules  19  in fixed relative positions. Each heat sink  20  includes: a base  22  with a back base-surface  223 , an opposite base-surface  224 , two base-ends  225  and first and second base-sides  221  and  222 ; a plurality of inner-fins  24  protruding from opposite base-surface  224 ; first and second side-fins  25  and  26  protruding from opposite base-surface  224  and terminating at distal fin-edges  251  and  261 , first side-fin  25  including a flange hook  252  positioned to engage distal fin-edge  261  of second side-fin  26  of adjacent heat sink  20 ; and first and second lateral supports  27  and  28  protruding from back base-surface  223 , lateral supports  27  and  28  each having inner portions  271  and  281 , respectively, and outer portion  272  and  282 , respectively Inner portions  271  and  281  of first and second lateral supports  27  and  28  have first and second opposed support-ledges  273  and  283 , respectively, that form a heat-sink-passageway  23  which slidably supports an LED-array module  19  against back base-surface  223 . First and second supports  27  and  28  of each heat sink  20  are in substantially planar alignment with first and second side-fins  25  and  26 , respectively. As seen in  FIGS. 10 and 11 , the flange hook is at  251  distal fin-edge of first side-fin  25 . 
         [0059]    Each heat sink  20  is a metal (preferably aluminum) extrusion with back base-surface  223  of heat sink  20  being substantially flat to facilitate heat transfer from LED-array module  19 , which itself has a flat surface  191  against back-base surface  223 . Each heat sink  20  also includes a lateral recess  21  at first base-side  221  and a lateral protrusion  29  at second base-side  222 , recesses  21  and protrusions  29  being positioned and configured for mating engagement of protrusion  29  of one heat sink  20  with recess  21  of adjacent heat sink  20 . 
         [0060]    As best seen in  FIGS. 1 ,  4 ,  5 ,  6 ,  10  and  11 , first and second side-fins  25  and  26  are each a continuous wall extending along first and second base-sides  221  and  222 , respectively Inner-fins  24  are also each a continuous wall extending along base  22 . Inner-fins  24  are substantially parallel to side-fins  25  and  26 . 
         [0061]      FIGS. 4 and 6  show an interlock of housing  12  to LED assembly  18 . As best seen in  FIGS. 10 and 11 , in each heat sink  20  inner-fins  24  include two middle-fins  241  each of which includes a fin-end  242  forming a mounting hole  243 . A coupler  52  in the form of a screw is engaged in mounting hole  243 , and extends from heat sink  20  to terminate in a coupler-head  521 . Housing  12  has a slotted cavity  54  which extends along, and is integrally formed with, each of border structures  40  forms the interlock by receiving and engaging coupler-heads  521  therein. 
         [0062]      FIG. 2  illustrates a version of the invention which is LED lighting fixture  10 B. In lighting fixture  10 B, perimetrical structure  12  includes a pair of nose structures  40  configured for wall mounting and one frame structure  30  in substantially perpendicular relationship to each of the two nose structures  40 . 
         [0063]    The substantially rectangular lighting fixture  10 A which is best illustrated in  FIGS. 1 ,  3  and  4 , perimetrical structure  12  includes a pair of opposed frame structures  30  and a pair of opposed first nose structure  40  and second nose structure  41 . The second nose structure  41  has two spaced sub-portions  41 A and  41 B with a gap  412  therebetween. Sub-portions  41 A and  41 B each include all of the nose-portion elements. Gap  412  accommodates a pole-mounting assembly  60 , one embodiment of which is shown in  FIGS. 1 ,  3 ,  4  and  12 , that is secured to LED assembly  18  between nose sub-portions  41 A and  41 B. 
         [0064]    Pole-mounting assembly  60  includes a pole-attachment portion  61  that receives and secures a pole  15  and a substantially air/water-tight section  62  that encloses electrical connections and has wire-apertures  64 . Each wire-aperture  64  communicates with nose-portion  42  chamber of a respective one of nose-structure sub-portions  41 A and  41 B. Nose-structure sub-portions  41 A and  41 B are in air/water-tight engagement with air/water-tight section  62  of pole-mounting assembly  60 . Air/water-tight section  62  includes grooves  621  on its opposite sides  622 ; grooves  621  are configured for mating engagement with end edges  413  of nose-structure sub-portions  41 A and  41 B. 
         [0065]    As best seen in  FIG. 12 , pole-mounting assembly  60  has a mounting plate  65  abutting LED assembly  18 , and fastener/couplers  66  extend from mounting plate  65  into engagement with mounting hole  243  of middle-fins  241 . 
         [0066]      FIGS. 8 and 9  show that frame-portion  32  of chamber  14  has a chamber-divider  33  across chamber  32  that divides frame-portion  32  of chamber  14  into an end part  321  and a main part  322 , which encloses electronic LED driver(s)  16 . Chamber-divider  33  has a divider-edge  331 . Chamber-divider  33  includes a substantially air/water-tight wire-passage therethrough in the form of a notch  332  having spaced notch-wall ends  334  that terminate at divider-edge  331 . A notch-bridge  38  spans notch  332  to maintain the air/water-tight condition of chamber  32 . Notch-bridge  38  includes a bridge-portion  381  and a pair of gripping-portions  382  which are configured for spring-grip attachment to notch-wall ends  334 . A removable cover-plate  31  seals main part  322  of frame-portion  32  of chamber  14  in substantially air/water-tight condition. 
         [0067]      FIGS. 2-6  show that inventive LED lighting fixtures  10  include a protective cover  11  that extends over LED assembly  18  and is secured with respect to housing  12 . Protective cover  11  has perforations  111  to permit air and water flow therethrough for access to and from LED assembly  18 . 
         [0068]    As best seen in  FIGS. 5 and 6 , LED lighting fixture  10  has a venting gap  56  between housing  12  and LED assembly  18 , to permit air and water flow from heat sink  20 . Venting gap  56  is formed by the interlock of housing  12  to LED assembly  18  or is a space along outer side-fins of the LED assembly. 
         [0069]      FIG. 13  shows an embodiment of the inventive lighting fixture  10 C in which frame structure  30 C is a sole frame structure, and housing  12 C is a substantially H-shaped structure with sole frame structure  30 C secured between mid-length positions of the pair of opposed border structures  40 C. 
         [0070]      FIG. 14  shows another embodiment of the inventive LED lighting fixture  10 D with housing  12 D formed by a pair of opposed border structures  40  and LED assembly  18  secured between border structures  40 . Lighting fixture  10 D, as shown on  FIG. 14 , includes a restraining-bracket  80  secured to housing  12 D by screws  85  through screw-holes  87 . Bracket  80  has a plurality of projections  82  each of which extends between adjacent fins of two of heat sinks  20 . Restraining bracket  80 , best shown on  FIG. 15 , is a comb-like structure with an elongated body  84  including a spine-portion  86  from which the plurality of projections  82  extend. Restraining-bracket  80  is configured and dimensioned for elongated body  84  to be fixedly secured to housing  12  and for projections  82  to snugly fit in spaces between adjacent heat-sink fins. 
         [0071]    While the principles of the invention have been shown and described in connection with specific embodiments, it is to be understood that such embodiments are by way of example and are not limiting.