Patent Document

BACKGROUND OF THE INVENTION 
   The present invention relates generally to illumination devices and, in particular, to a free-standing utility light having a light source configured as an array of LEDs. 
   Portable lights that can be manually moved and suspended about a work site to aid a user to obtain the best lighting conditions, are well known. Such lights are often referred to as trouble lamps, extension lights, work lights, inspection lights, utility lights, and the like, and are commonly employed by mechanics and other workers who require a concentration of light while frequently changing locations. Such lights have developed from using incandescent bulbs to using fluorescent bulbs. The fluorescent bulbs have several advantages in use as compared with the incandescent bulbs. For example, a fluorescent light bulb usually provides more light with less glare than an incandescent light bulb of the same wattage. 
   Many prior art utility lights are designed to be handheld, which is advantageous in that they may be easily moved to many locations. While their portability and light weight is advantageous, handheld lights are often limited in the amount of illumination that they can provide because the larger bulbs, support assemblies and power supply components required to provide more illumination increase the weight and would make the handheld light more difficult to hold and orient. Those skilled in the art will also appreciate that though a greater amount of illumination is preferred at times, the same amount of illumination is not in required for every work location. 
   Light emitting diodes (LEDs) are well known for providing illumination to digital displays and the like. It has become more common for an array of LEDs to be utilized for providing illumination in work spaces. LEDs are particularly advantageous because of their low power consumption per candlepower produced when compared to incandescent light bulbs and, to a lesser degree, to fluorescent light bulbs. 
   It is desirable to provide a utility light having lower power consumption that also provides sufficient illumination for a work site. It is also desirable to be able to place and orient the utility light in as many locations and positions as possible. It is always desirable to provide utility lights that are lightweight and cost-effective to produce. 
   SUMMARY OF THE INVENTION 
   The present invention concerns an LED utility light having a housing and a lens member enclosing at least one LED circuit board assembly and a reflector member mounted in the housing. Preferably, an O-ring is disposed between the housing and the lens member. The assembled housing and lens member are pivotally mounted on a stand for rotation about a horizontal axis. Once positioned, the housing and lens can be locked against further rotation relative to the stand. The stand functions as a base to support the utility light in a freestanding position, as a mounting bracket for attaching to a surface. The reflector member has a reflective surface facing the lens member. 
   The housing is generally square with a rear wall and a peripheral wall extending forwardly from the rear wall forming a front opening closed by the lens. A first group of less than all of the LEDs is mounted on an inner circuit board assembly wherein the rear wall, the inner circuit board assembly and a central portion of the lens extend in generally parallel planes. The LEDs not included in the first group are mounted on a plurality of outer circuit board assemblies positioned around the inner circuit board assembly. Each of the outer circuit board assemblies and an associated outer portion of the lens extend in generally parallel planes angled relative to the plane of the rear wall. A switch connected to the LEDs selectively applies electrical power to the first group in a first switch mode and applies electrical power to a second group of the LEDs in a second switch mode, the second group being one of all of the LEDs and all of the LEDs not included in the first group. 

   
     DESCRIPTION OF THE DRAWINGS 
     The above, as well as other advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which: 
       FIG. 1  is a front perspective view of an LED utility light with stand in accordance with the present invention; 
       FIG. 2  is a rear elevation view of the LED utility light of  FIG. 1  shown without the stand; 
       FIG. 3  is an exploded perspective view of the LED utility light of  FIG. 1 ; 
       FIG. 4  is a perspective view of the interior of the housing of the utility light shown in  FIG. 1 ; 
       FIG. 5  is a cross-sectional view taken along line  5 — 5  in  FIG. 2 ; 
       FIG. 6  is a cross-sectional view taken along line  6 — 6  in  FIG. 2 ; and 
       FIG. 7  is an electrical schematic of the utility light shown in  FIG. 1 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to all of the Figures, a utility light in accordance with the present invention is indicated generally at  10 . The utility light  10  includes a generally square housing  12  having a peripheral wall  14  formed in four straight portions shown in  FIG. 4  as a pair of opposed side portions  14   a , a top portion  14   b  and a bottom portion  14   c . The portions  14   a ,  14   b  and  14   c  are connected by four rounded corners  14   d  and extend forwardly from the periphery of a rear wall  16  thereof. The wall  14  has a groove  18  formed in a forwardly facing free edge  20  for cooperating with a lens member, discussed in more detail below, and includes a pair of preferably threaded studs  22  each extending outwardly from an associated pad  23  on an exterior surface  24  of the opposed side portions  14   a . The free edge  20  also includes a peripheral flange  26  extending outwardly from the exterior surface  24 . The flange  26  has a slot  28  formed between opposed ribs centered along each of the portions  14   a ,  14   b  and  14   c , the slots and the ribs extending rearwardly from the free edge  20 . The slots  28  are defined by a flat  32  extending between the ribs  30 . 
   The rear wall  16  of the housing  12  includes a plurality of bosses  34  extending forwardly from an interior surface adjacent the corners  14   d , each boss having an aperture extending therethrough for receiving fasteners  36  ( FIG. 2 ) when the utility light  10  is assembled. An annular rib  38  is centered on the interior surface of the wall  16 . A plurality of inner brackets  40  that are each spaced an approximately equal radial distance from the central rib  38  extend inwardly from the interior surface of the wall  16 . Each of the brackets  40  is positioned centrally relative to an associated one of the straight portions of the wall  14 . An upper surface  40   a  of each of the inner brackets  40  is substantially parallel to the interior surface of the wall  16 . Two of the inner brackets  40  have a radially outwardly spaced auxiliary bracket  41  connected thereto adjacent the side portions  14   a . A plurality of outer brackets  42  extend inwardly from the interior surface of the wall  16  and are located at a greater radial distance from the central flange  38  than the inner brackets  40 . Each of the brackets  42  is positioned radially between an associated one of the bosses  34  and the rib  38 . An upper surface  42   a  of each of the outer brackets  42  is preferably sloped radially downwardly toward the central rib  38 , best seen in  FIG. 6 , such that a radial outward portion of the upper surface  42   a  is at a greater distance from the interior surface of the wall  16  than a radial inward portion of the upper surface  42   a.    
   An exterior surface  44  of the rear wall  16  and the peripheral wall top portion  14   b  have a recess or depression  46  formed therein. The recess  45  is centered along the top portion  14   b  and is defined by three side walls  48  and a bottom wall  49  having a switch aperture  50  formed therein. A tubular power cord passage  52  extends inwardly from the interior surface of the rear wall  16  near the bottom portion  14   c . The apertures  35  of the bosses  34  extend through the rear wall  16  for receiving the fasteners  36 . An upper alignment bracket  43   a  extends forwardly from one of inner walls  48  of the depression  46  and a lower alignment bracket  43   b  extends forwardly from the interior surface of the rear wall  16  between the power cord passage  52  and the bottom portion  14   c.    
   A central printed circuit board (PCB)  54  is mounted in the housing  12  on a pair of mounting posts  56  extending forwardly from the interior surface of the rear wall  16  between the central rib  38  and associated ones of the brackets  40 . An inner LED circuit board assembly  58  and a plurality of outer LED circuit board assemblies  60  are mounted in the housing  12  between a reflector member  62  and the brackets  40 ,  41 ,  42 ,  43   a , and  43   b . The LED circuit board assembly  58  is generally square and includes a plurality of LEDs  64  mounted on a front surface  66  thereof. Each of the outer LED circuit board assemblies  60  is generally rectangular with two angled corners and includes a plurality of LEDs  68  mounted on a front surface  70  thereof. As seen in  FIG. 3 , each of the outer LED circuit board assemblies  60  is positioned adjacent an associated edge of the inner LED circuit board assembly  58  such that the angled corners cooperate to prevent overlap. The LEDs form an array with the LEDs  64  being a center of the array and the LEDs  68  being a periphery of the array. 
   The reflector member  62  is positioned between the circuit board assemblies  58  and  60  and a lens member  72  and includes a plurality of spaced apart through apertures  4 . The front surface of the reflector member  62  is preferably mirror chrome plated or has a similar highly reflective surface. The apertures  74  correspond in number and position to the LEDs  64  and  68  on the circuit board assemblies  58  and  60 . The walls of the reflector member  62  that define each of the apertures  64  are also mirror chrome plated and taper radially outwardly from a rear surface of the reflector member  62  to the front surface of the reflector member  62  to form a generally cone-shape profile, best seen in  FIGS. 5 and 6 . The reflector member  62  includes a plurality of tabs  76  extending rearwardly therefrom for cooperating with the brackets  41 ,  43   a , and  43   b  when the utility light  10  is assembled. The reflector member  62  is preferably formed generally concave or cone-shaped or dish-shaped, best seen in  FIG. 2 , wherein a plurality of peripheral portions  62   a  of the reflector member  62 , corresponding to the outer LED circuit board assemblies  60 , slopes rearwardly toward a central portion  62   b  of the reflector member  62  corresponding to the inner LED circuit board assembly  58 . 
   A gasket or O-ring  78  is adapted to be disposed in the groove  18  between the forwardly facing surface  20  of the peripheral wall  14  and a corresponding mating surface of the lens member  72 . The exterior surface of the lens member  72  includes a plurality of outer portions  72   a  sloping rearwardly towards a central portion  72   b . The outer portions  72   a  correspond to the peripheral portions  62   a  of the reflector member  62  and the central portion  72   b  corresponds to the central portion  62   b  of the reflector member  62 . The lens member  72  is preferably formed of a transparent material and includes a plurality of hooks  80  extending therefrom that preferably correspond in number and location to the slots  28  formed in the housing  12 . Each of the hooks  80  includes an engagement portion  82 , best seen in  FIG. 5 , that snaps over a corresponding one of the flats  32  when the utility light  10  is assembled. The hooks  80  can be released by finger pressure to release the lens  72  from the housing  12 . 
   A plurality of hollow posts  84 , best seen in  FIG. 6 , extend from an inner surface of the lens member  72  and through corresponding apertures  85  formed in the reflector member  62 . The bosses  34  of the housing  12  are counterbored to recess the fasteners  36  when the utility light  10  is assembled. The fasteners  36  each extend through a gasket or O-ring  37  that, in conjunction with the O-ring  78 , assist in ensuring a watertight seal of the interior of the assembled utility light  10 . Each of the fasteners  36  threadably engages an associated tubular retainer or nut  83  that is slidably received in a corresponding one of the hollow posts  84 . 
   A strain relief means  86  is adapted to be disposed in the power cord passage  52  to receive a power cord, shown in  FIGS. 3 ,  5 , and  6  in phantom at  88 , to provide power to the circuitry, discussed below, that is enclosed within the light  10 . A switch  90  is received in the switch aperture  50 . The switch  90  is preferably a push button type that electrically connects power from a power source  92  connected to the power cord  88  to an input of a conventional AC/DC power converter  94 , best seen in  FIG. 7 . The converter  94  can be a separate unit mounted in the housing  12 , or can be a circuit on the circuit board  54 , as shown in  FIG. 7 . The LEDs  64  and  68  are connected to an output of the converter  94  through the switch  90  and are operable to emit light in a well-known manner when a DC voltage is provided by the converter  94 . 
   The utility light  10  includes a generally U-shaped stand  96  having a pair of upstanding legs  98  extending from opposite ends of a generally planar bar  100 . An upper end of each of the legs  98  includes an aperture  102  through which extends an associated one of the threaded studs  22  of the housing  12 . Each of a pair of knobs  104  threadably engages a free end of an associated one of the studs  22  to retain the associated leg  98  on the stud  22 . A washer  106  is positioned between the surface  23  and the facing surface of the leg  98  adjacent the aperture  102 . When the knobs  104  are tightened, the legs  98  are held against rotation about the studs  22  so that the housing  12  of the utility light  10  cannot move relative to the stand  96 . When the knobs  104  are loosened, the housing  12  can be rotated relative to the stand  96  about a horizontal axis X extending through the studs  22 , best seen in  FIG. 1 . The studs  22  are positioned approximated midway between the top and bottom portions  14   b  and  14   c . Thus, the direction of the illumination emitted from the lens  72  can be selectively rotated 360 degrees about the axis X as shown by arrows  108  in  FIG. 1  and the housing  12  can be locked in a desired position utilizing the knobs  22 . 
   A pair of feet  110  are attached at the juncture of the legs  98  with the bar  100 . The feet  110  extend transversely from opposite edges of the bar  100  and have lower surfaces that may include grip cushions  112  attached thereto, such as by adhesive or the like, for supporting the utility light  10 . Formed in the bar  100  are slotted apertures  114  each for receiving a head of a fastener (not shown). The housing  12 , the knobs  104  and the feet  110  can be formed from a suitable plastic material such as an ABS material or the like. The lens  72  can be formed from another suitable plastic material such as a polycarbonate material or the like. 
   In a mode of use, the utility light  10  can rest freestanding supported on a generally horizontal surface by the bar  100  and the feet  110 . The housing  12  can be rotated about the first axis X to direct the illumination emitted from the lens  72 . In another mode of operation, the slotted apertures  114  can accept the heads of screws (not shown) for mounting the utility light  10  on a generally planar surface permitting the housing  12  to be rotated about the first axis X to direct the illumination. In yet another mode of operation, the utility light  10  can be held in a hand using the stand  96  as a handle. 
   An electrical schematic of the utility light  10  is shown in  FIG. 7 . The AC to DC converter  94  is provided for converting AC power from the power source  92 , when the power cord  88  is connected to the power source  92 , to the lower voltage DC power required to power the LEDs  64  and  68  of the LED circuit board assemblies  58  and  60 , respectively. 
   The electrical power from the converter  94  is directed through the switch  90  to the LED circuit board assemblies  58  and  60 . The switch  90  has at least a pair of “on” positions wherein in a first “on” position the switch  90  can direct electrical power from the converter  94  to a first group  116  of the LEDs wherein only those LEDs  64  in the central are lighted. In a second “on” position, the switch  90  directs power to light the first group  116  and a second group  118  including all of the LEDs  68 . 
   The utility light  10  shown in  FIGS. 1–6  has the LEDs  64  on the circuit board assembly  58  arranged in six columns of six rows for a total of thirty-six LEDs. The LEDs  68  on each of the circuit board assemblies  60  are arranged in two columns having seven and nine LEDs  68 , respectively, for a total of sixty-four LEDs. The total number of the LEDs  64  and  68  of the utility light  10  is one hundred. As explained above, the LEDs  64  can be the first group  116  such that thirty-six percent of the total light output is generated in the first “on” position of the switch  90 . 
   Those of ordinary skill in the art will recognize that the switch  90  can be two separate switches wherein the group  116  can be controlled by one switch and the group  118  can be controlled by the other switch such that all of the LEDs  64  and  68  are lighted when both switches are “on”. Of course, any number of LEDs can be used and divided into the groups as desired. Further, the switch  90  can have only one “on” position for turning on and off all of the LEDs  64  and  68 . 
   In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.

Technology Category: f