Patent Publication Number: US-9845945-B1

Title: Full-cutoff LED luminaire with front-pivot power door and heat sink with refractor mounting

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of and claims priority under 35 U.S.C. §120 to U.S. Non-Provisional patent application Ser. No. 14/014,200, titled “Full Cutoff LED Luminaire with Front-Pivot Power Door and Heat Sink with Refractor Mounting,” and filed Aug. 29, 2013, the entire content of which is hereby incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to outdoor luminaires. Specifically, the present disclosure relates to full cutoff light emitting diode (LED) luminaires. 
     BACKGROUND 
     Dusk to dawn luminaires are generally used to provide outdoor lighting during dark hours of the day, and are often used in open areas such as farms as nighttime security lighting. Conventionally, dusk to dawn luminaires use high intensity discharge (HID) lamps as light sources. Such luminaires are also used with a particular reflector/refractor design which is controlled and standardized according to American National Standardization Institute (ANSI) standards. 
     However, dusk to dawn luminaires are an example of nighttime lighting that may contribute to light pollution. More generally, increase in industrialization has caused an increase in use of many types of lighting, including interior building light, street lamps, commercial signage lights, safety lights, and the like. As a side effect of increased lighting needs, the amount of light pollution has increased as well. One solution for decreasing the amount of light pollution is the use of full cutoff luminaires. Full cutoff luminaires are generally configured to direct light downward and eliminate uplight, or illumination above the horizontal of the luminaire. 
     Thus, it would be beneficial for dusk to dawn luminaires to be configured as full cutoff luminaires. Additionally, the lighting industry has recognized the advantages of light emitting diode (LED) light sources over more traditional light sources, such as HID lamps. However, many challenges have prevented the effective design of a full cutoff LED dusk to dawn luminaire. Such challenges include, but are not limited to, the fact that LED light sources have different power and heat dissipation needs, which require different electrical and structural design. Additionally, users of dusk to dawn luminaires are familiar with and often require their dusk to dawn luminaires to be compatible with the conventional ANSI standard reflector/refractor. 
     SUMMARY 
     In an example embodiment of the present disclosure, a full cutoff luminaire includes a housing, a power door, a heat sink, and at least one light source. In such an example embodiment, the housing further includes an open side and a mounting end. The power door is coupled to the open side of the housing via a hinge at a first end of the power door and a releasable coupling mechanism elsewhere on the power door. When the coupling mechanism is released, the power door pivots at the hinge and swings away from the housing and the mounting end. The heat sink is coupled to the first end of the power door opposite the housing. The at least one light source is coupled to the heat sink opposite the power door. 
     In another example embodiment of the present disclosure, a full cutoff luminaire includes a lighting fixture. The lighting fixture further includes a housing, a heat sink, at least one light source, and a mounting end coupled to the housing. The heat sink is coupled to the housing. Additionally, the heat sink further includes at least one attachment mechanism configured to optionally couple the heat sink to one or more different reflectors or refractors. The at least one light source is coupled to the heat sink opposite the housing. 
     In another example embodiment, a luminaire includes a housing, a power door, a heat sink, and at least one light source. The housing further includes an open side and a mounting end. The power door is coupled to the open side of the housing via a hinge at a first end of the power door and a releasable coupling feature elsewhere on the power door. The power door swings away from the mounting end, pivoting at the hinge, when the coupling feature is released. The heat sink is coupled to the power door opposite the housing, in which the heat sink further comprises at least one attachment feature configured to optionally couple the heat sink to one or more types of reflectors or refractors. The at least one light source is coupled to the heat sink opposite the power door. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the disclosure and the advantages thereof, reference is now made to the following description, in conjunction with the accompanying figures briefly described as follows: 
         FIG. 1  illustrates a full cutoff LED luminaire in a default configuration, in accordance with an example embodiment of the present disclosure; 
         FIG. 2  illustrates an exploded view of the full cutoff LED luminaire of  FIG. 1 , in accordance with an example embodiment of the present disclosure; 
         FIG. 3  illustrates a full cutoff LED luminaire with an optional refractor optic, in accordance with an example embodiment of the present disclosure; 
         FIG. 4  illustrates a full cutoff LED luminaire with an American National Standards Institute (ANSI) reflector/refractor assembly, in accordance with an example embodiment of the present disclosure; and 
         FIG. 5  illustrates a detailed view of a coupling mechanism between the full cutoff LED luminaire and ANSI reflector assembly of  FIG. 4 , in accordance with an example embodiment of the present disclosure. 
     
    
    
     The drawings illustrate only example embodiments of the disclosure and are therefore not to be considered limiting of its scope, as the disclosure may admit to other equally effective embodiments. The elements and features shown in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of example embodiments of the present disclosure. Additionally, certain dimensions may be exaggerated to help visually convey such principles. 
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     In the following paragraphs, the present disclosure will be described in further detail by way of example with reference to the attached drawings. In the description, well known components, methods, and/or processing techniques are omitted or briefly described so as not to obscure the disclosure. As used herein, the “present disclosure” refers to any one of the embodiments of the disclosure described herein and any equivalents. Furthermore, reference to various feature(s) of the “present disclosure” is not to suggest that all embodiments must include the referenced feature(s). 
     The present disclosure provides a full cutoff luminaire having light emitting diodes (LEDs) as light sources. Furthermore, the full cutoff luminaire is operable as a full cutoff luminaire in a base configuration, and is also couplable to one or more different types of reflectors and/or refractors, giving users a breadth of configuration options.  FIG. 1  illustrates a perspective view of a full cutoff luminaire  100  in a base configuration, in accordance with example embodiments of the present disclosure.  FIG. 2  illustrates an exploded view of the full cutoff luminaire  100  of  FIG. 1 . With reference to  FIGS. 1 and 2 , in certain example embodiments, the full cutoff luminaire  100  includes an upper housing  102 , a power door  110 , a heat sink  104 , an LED optic  108 , a photocell component  114 , and a mounting mechanism  112  for coupling the full cutoff luminaire  100  to a mounting structure, such as a wall, post, and the like. Further illustrated in  FIG. 2 , in certain example embodiments, the full cutoff luminaire  100  also includes an LED board  210 , an o-ring  208 , an LED driver  204 , and a terminal block  202 . In certain example embodiments, the base configuration of the full cutoff luminaire  100  does not include an additional reflector or reflector. Rather, the configuration of the LED board  210 , the LED optic  108 , and the heat sink allows the full cutoff luminaire  100  to provide full cutoff illumination in the base configuration. 
     In certain example embodiments, the upper housing  102  includes a top side (not shown), and one or more lateral sides  121  extending substantially orthogonally from and substantially encircling the perimeter of the top side. The top side and the one or more lateral sides  121  form an open cavity  214  therein. In other example embodiments, the upper housing  102  takes on a shape or configuration different than that described in the present example. In the example embodiment, the power door  110  is coupled to the upper housing  102  by coupling to the one or more lateral sides  121  opposite the top side. Alternatively worded, the upper housing is open on one side and the power door  110  is disposed on said side. 
     Specifically, in certain example embodiments, the power door  110  is coupled to the upper housing  102  via a hinge  106  at a first end  124  of the power door  110 . In certain example embodiments, the hinge  106  includes a cup component  106   a , which is attached to the upper housing  102 , and an arm component  106   b , which is attached to the power door  110 . The arm component  106   b  snaps into and is retained by the cup component  106   a  while maintaining a range of rotational motion within the cup component  106   a . The hinge  106  is disposed at an outer edge of the upper housing  102  and power door  110 . The power door  110  is further coupled to the upper housing  102  via a releasable attachment mechanism  122  at a second end  126  of the power door  110  opposite the hinge  106 . 
     In one example embodiment, the attachment mechanism  122  includes a screw (not shown) threaded through a corresponding apertures in the power door  110  and into a threaded screw hole in the upper housing  102 , thereby securing the power door  110  to the upper housing  102  in a closed position. When the screw  122  is removed, the power door  110  is able to swing apart from the upper housing  102 , pivoting at the hinge  106 , into an open position. In certain other example embodiments, the attachment mechanism  122  is a latch, clip, lock, or the like. In certain example embodiments, the terminal block  202  and the LED driver  204  are housed in the cavity  214  within the upper housing  120  and accessible via the power door  110 . During normal use, the power door  110  is in the closed position with the terminal block  202  and LED driver  204  contained therein and substantially protected from the environment. However, if maintenance of the terminal block  202 , LED driver  204 , or wire connections is needed, such elements are easily accessible by opening the power door  110 . 
     In certain example embodiments, the luminaire  100  is coupled to a mounting structure via the mounting mechanism  112 . The mounting mechanism is disposed at a mounting end  128  of the upper housing  102  and close to the second end  126  of the power door  110 . Thus, when the attachment mechanism  122  is released, the power door  110  swings away from the mounting mechanism  112  and away from the mounting structure when the luminaire  100  is mounted. As such, the power door  110  and any components mounted on the power door  110  are prevented from swinging into the mounting structure, which may potentially damage the luminaire  100 . In certain example embodiments, the mounting mechanism  112  includes an internal wall for biasing a mounting bracket. In certain example embodiments, the mounting structure is a pole, a wall, or the like. 
     In certain example embodiments, the heat sink  104  is coupled to the power door  110  near the first end  124  of the power door  110 , and facing away from the upper housing  102 . The heat sink  104  is disposed against an outer surface of the power door  110  such that the heat sink  104  and the power door  110  are substantially parallel and travel together as the power door  110  opens or closes. As the heat sink  104  is disposed at the first end  124  of the power door  110  and substantially adjacent to the hinge  106 , the heat sink  104  travels a minimal distance when the power door  110  swings open or is closed. Additionally, the heat sink  104  swings away from the mounting structure  112  when the power door  110  opens. Thus, the heat sink  104 , being on the outside of the power door  110 , is prevented from swinging into the mounting structure when the coupling mechanism of the power door  110  is released and the power door  110  swings down and outward. In certain example embodiments, the heat sink  104  is circular and includes a plurality of heat sink fins  206  radially extending therefrom. In certain other example embodiments, the heat sink  104  takes on a different geometric or non-geometric shape and includes heat sink fins  206  configured differently than those shown in  FIGS. 1 and 2  and as described above. For example, in alternate embodiments, the heat sink fins can be oriented in a horizontal direction and/or can be curved. 
     The heat sink  104  further includes a recessed surface  220  and/or an inner ledge  216  in which the LED board  210  is disposed and retained. The heat sink  104  facilitates dissipation of heat from the LEDs on the LED board  210 . In certain example embodiments, the LED optic  108  is also disposed on or in the heat sink  104  in parallel with and proximate to the LED board  210  such that the LED board  210  is substantially between the LED optic  108  and the heat sink  104 . The LED optic  108  may diffuse or focus light from the LEDs on the LED board  210  in a desired manner, depending on the specifications of the LED optic  108 . In certain example embodiments, the LED optic  108  is fabricated from a polycarbonate material and may protect the LED board  210  from the environment, such as weather, debris, vandalism, and other potentially damaging elements. 
     The heat sink  104  further forms an open-ended cavity  218  extending from the LED board  210 , at one end of the heat sink  104 , to the power door  110 , at the other end of the heat sink  104 . The power door  110  further includes an opening (not shown) aligned with the cavity  218  such that the cavity  218  and the opening in the power door  110  provide an aperture from the LED board  210  to the interval cavity  214  of the upper housing  102 . The internal cavity  214  of the upper housing  102  includes an LED driver  204  disposed therein. In certain example embodiments, the LED driver  204  is coupled to a terminal block  202  also disposed within the upper housing  102 . When the luminaire  100  is installed, the terminal block  202  is coupled via electrical wire to an external power source, such as building lines, power lines, and the like. Accordingly, the LED driver  204  receives power from such sources via the terminal block  202 . In certain other example embodiments, the terminal block  202  and the LED driver  204  are integrated. The LED driver  204  processes and conditions the received power into DC power suitable for powering the LEDs on the LED board  210 . The LED driver  204  provides the conditioned power to the LED board  210  via a plurality of wires (not shown) coupling the LED driver  204  and the LED board  210 . Specifically, in certain example embodiments, the wires are electrically coupled to the LED driver  204  at a first end, traverse the opening in the power door  110  and the cavity  218  in the heat sink  104 , and electrically couple to the LED board  210  at a second end, thereby providing the conditioned power from the LED driver  204  to the LED board  210 . In certain example embodiments, an o-ring is disposed between a portion of the recessed surface  220  or inner ledge  216  of the heat sink  104  and the LED board  210  and/or LED optic  108 . The o-ring may prevent environmental containments such as dust, moisture, and the like from reaching LEDs, circuitry, terminals, conductors, and other sensitive elements within the heat sink  104 . 
     In certain example embodiments, the luminaire  100  includes a photocell socket  114 . The photocell socket  114  includes a controller and a light sensor configured to detect ambient light levels. In such examples, operation of the luminaire is configured to be controlled by the photocell socket  114  depending on the detected light level. For example, in the embodiment of a dusk to dawn lighting application, the luminaire  100  turns on when the detected ambient light falls below a preset threshold and turns off when the detected ambient light goes above a preset threshold. In certain other example embodiments, the luminaire includes a clock timer (not shown). In such embodiments, the luminaire may be controlled according to the time of day. For example, in certain example embodiments, the luminaire  100  turns on at a preset time and turns off at a preset time. Alternatively, the luminaire  100  can be turned on and off manually via a switch. In certain example embodiments, the switch is located remote from the luminaire. 
     In certain example embodiments, the base full cutoff luminaire  100  of  FIG. 1  provides full cutoff illumination without additional reflectors, refractors, or shades. Light provided from the luminaire  100  is downwardly projected and substantially does not go above the horizontal plane of the luminaire  100 . Such a lighting configuration decreases the amount of light pollution it might otherwise generate. 
     In certain example embodiments, the base full cutoff luminaire  100  of  FIG. 1  is readily and optionally couplable with one or more reflectors, refractors, shades, and the like, of different styles. For example,  FIG. 3  illustrates one example embodiment in which a luminaire  300  is coupled to an acrylic drop refractor  302 , in accordance with an example embodiment of the present disclosure. In certain example embodiments, the refractor  302  is substantially cylindrical, with a first end  306  and a second end  308 . In certain example embodiments, the second end  308  has a smaller circumference than the first end  306 . An internal surface  310  of the refractor  302  includes a light refractive pattern for diffusing light from the LEDs. In certain example embodiments, the first end  306  of the refractor  302  includes a lip  312 . The refractor  302  is coupled to an outer edge  314  of the heat sink  104  via the lip  312 . In certain example embodiments, the refractor  302  is secured to the heat sink  104  via one or more screws  304 . Specifically, in such embodiments, the heat sink  104  includes one or more threaded screw-holes and the refractor  302  includes one or more screw-holes which align with the threaded screw-holes of the heat sink  104  when the refractor  302  is in the appropriate position relative to the heat sink  104 . Screws  304  are threaded into and retained by the threaded screw-holes in the heat sink, traversing the screw-holes in the refractor  302 . The refractor  302  is thereby secured to the heat sink  104  as shown in  FIG. 3 . In certain other example embodiments, the refractor  302  is attached to the heat sink  104  via other coupling mechanisms, such as latches, clips, snaps, and the like. 
     In certain example embodiments, the same base full cutoff luminaire  100  is readily and optionally coupled to an existing reflector/refractor assembly  402  such as the American National Standards Institute (ANSI) reflector/refractor assembly  402 .  FIG. 4  illustrates such a configuration according to an example embodiment of the present disclosure. Referring to  FIG. 4 , the luminaire  400  includes the ANSI reflector/refractor assembly  402 . The ANSI reflector/refractor assembly  402  further includes a reflector bowl  404  and a refractor optic  406 , in which the reflector bowl  404  couples to the heat sink  104  at one end and the refractor optic  406  at the other end. 
     In certain example embodiments, the ANSI reflector/refractor assembly  402  is optionally coupled to the base luminaire  100  via the heat sink  104 .  FIG. 5  illustrates a detailed view of the attachment between the heat sink  104  and the ANSI reflector/refractor assembly  402 , in accordance with an example embodiment of the present disclosure. Specifically, in certain example embodiments and as illustrated in  FIG. 5 , the heat sink  104  includes a fin  118  which includes a hooked portion  116 . The reflector bowl  404  includes a latching mechanism  502  which latches onto the hooked portion  116  of the fin  118 , thereby locking the ANSI reflector/refractor assembly  402  to the heat sink  104 . In certain example embodiments, the latching mechanism  502  is a bail latch. As discussed above, the same full cutoff luminaire  100  is capable of interchangeably coupling to the ANSI reflector/refractor assembly  402  or the acrylic drop refractor  402 . Alternatively stated, in certain example embodiments, the full cutoff luminaire  100  includes coupling mechanisms for retaining both the ANSI reflector/refractor assembly  402  and the acrylic drop refractor  302 . The full cutoff luminaire  100  is also fully functional as a full cutoff luminaire  100  when it is not coupled to any reflector or refractor. The ANSI reflector/refractor assembly  402  illustrated in  FIG. 4  and the acrylic drop refractor  302  illustrated in  FIG. 3  are examples of reflector and refractor configuration that are compatible with the full cutoff luminaire  100 . However, in other example embodiments, the full cutoff luminaire  100  can be used with reflectors and refractors of other configurations other than those described herein. 
     Accordingly, although embodiments of the present disclosure have been described herein in detail, the descriptions are by way of example. The features of the disclosure described herein are representative and, in alternative embodiments, certain features and elements may be added or omitted. Additionally, modifications to aspects of the embodiments described herein may be made by those skilled in the art without departing from the spirit and scope of the present disclosure defined in the following claims, the scope of which are to be accorded the broadest interpretation so as to encompass modifications and equivalent structures.