Patent Publication Number: US-6338564-B1

Title: Optical housing with vertical light source

Description:
FIELD OF THE INVENTION 
     The present invention relates to an overhanging luminaire or light fixture for both indoor and outdoor use. The light fixture has a two piece optical housing including a blank folded into a box with a base and four walls, and a reflector mounting plate coupled to the four walls. A set of reflectors is mounted to the reflector mounting plate such that a light source extends vertically in the center of and partially beyond the set of reflectors. 
     BACKGROUND OF THE INVENTION 
     Overhanging light fixtures are common to the lighting industry. Conventional light fixtures have optical housings in which the walls, the base and the reflector mounting plate are separately manufactured. The separate pieces must then be assembled using any of various methods, such as, fasteners, bent tabs, welding, brackets or glue. These optical housings can be difficult and time consuming to assemble and costly to manufacture. 
     In addition, conventional optical housings have light sources where the entire length of the light source is laterally surrounded by reflectors. The light source is mounted either horizontally or vertically at the pinnacle of the reflector assembly. This design requires a powerful light source to provide the proper light beam configuration and creates a significant amount of light pollution. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide a light fixture with a two piece optical housing having walls that are unitarily formed with the base along folds, thereby reducing the manufacturing and assembly time and expense. 
     Another object of the present invention is to provide a light fixture with an optical housing having a vertical light source that partially extends beyond the reflectors, reducing the power required for lighting and reducing the light pollution emitted. 
     The foregoing objects are basically attained by providing an optical housing with a base and four walls, each wall is coupled to the base along a unitary fold. A reflector mounting plate is coupled to the walls with reflectors mounted to the reflector mounting plate in a predetermined reflector pattern. A light source extends approximately in the center of the reflectors. 
     By forming the optical housing in this manner, the housing is reduced to two pieces that are easy to manufacture and assemble. The housing may be stored flat with the walls and base in an unfolded configuration, increasing the number of housings that may be stored over conventional housings stored in a standard assembled box configuration. Additionally, the housing uses a relatively low power light source to create the desired light beam configuration, while simultaneously reducing light pollution. 
     Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Referring to the drawings which form apart of this disclosure: 
     FIG. 1 is a side elevational view in section of the light fixture in accordance with a first embodiment of the present invention. 
     FIG. 2 is a bottom perspective view of the optical housing of the light fixture illustrated in FIG.  1 . 
     FIG. 3 is a bottom perspective view in section of the optical housing illustrated in FIG.  2 . 
     FIG. 4 is a top perspective view of the optical housing illustrated in FIG. 2 
     FIG. 5 is a top plan view of the blank, including the base and four walls, for the optical housing illustrated in FIG. 3, prior to assembly. 
     FIG. 6 is a bottom plan view of the reflector mounting plate illustrated in FIG. 2, prior to assembly. 
     FIG. 7 is a front elevational view of the first reflector illustrated in FIG.  2 . 
     FIG. 8 is a bottom perspective view of the second reflector illustrated in FIG.  2 . 
     FIG. 9 is a bottom perspective view of the third reflector illustrated in FIG.  2 . 
     FIG. 10 is a side elevational view of the reflector strip illustrated in FIG.  2 . 
     FIG. 11 is a side elevational view of the bracket illustrated in FIG.  4 . 
     FIG. 12 is a bottom perspective view of an optical housing according to a second embodiment of the present invention. 
     FIG. 13 is a top perspective view of the optical housing illustrated in FIG.  12 . 
     FIG. 14 is a top plan view of the blank, including the base and four walls, for housing illustrated in FIG. 12, prior to assembly. 
     FIG. 15 is a bottom plan view of the reflector mounting plate illustrated in FIG. 12, prior to assembly. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring initially to FIGS. 1-11, a light fixture  10  according to a first embodiment of the present invention has a mounting housing  11  with an optical housing  12  and a lens  13  encased in lens frame  14  coupled to it. Lens frame  14  is pivotally hinged through screw  15  to mounting housing  11 , allowing access to the optical housing. Optical housing  12  comprises a reflector mounting plate  16  and a base  18  with four walls  20 ,  22 ,  24 , and  26  attached to base  18  along unitary fold lines  28 ,  30 ,  32 , and  34 . Reflector mounting plate  16  is coupled to walls  20 ,  22 ,  24 , and  26  and has reflector set  36  mounted to it in reflector pattern  38 . A reflector strip  40  is mounted to reflector mounting plate  16  in a generally circular pattern around reflector pattern  38 . A reflector set  42  extends from base  18  in a circular pattern, while a reflector  44  is mounted by bracket  46  in the center of reflector set  42 . A light source  48 , mounted to bracket  46 , extends through the center of reflector  44 . 
     Base  18  and walls  20 ,  22 ,  24 , and  26  of optical housing  12  are manufactured as a flat planar metal blank (FIG.  5 ). Base  18  is preferably square with a circular hole  50  in its center, but may be any suitable design, such as a rectangle. Small tab slots  52  extend through base  18  and are arranged in a pattern similar to reflector pattern  38  around hole  50 . Slots  52  hold one side of each reflector  76  in reflector set  36 . Additionally, base  18  has screw holes  54  oriented in a circular pattern around hole  50 , inside of and in close proximity to reflector pattern  38  for mounting reflector set  42 . 
     Walls  20 ,  22 ,  24 , and  26  are manufactured coplanar with base  18  and extend therefrom. Unitary fold lines or scores  28 ,  30 ,  32 , and  34  extend the length of the walls and separate the walls from the base. The walls are rectangular in shape, and each wall has two tabs  56  extending from edge  60  opposite the respective fold line. 
     Reflector mounting plate  16  (FIG. 6) is a flat planar metal plate with reflector pattern  38  defining the interior of optical housing  12 . The reflector mounting plate is preferably square. Each reflector mounting plate edge is slightly longer than each edge of base  18 , creating a plate with an area slightly larger than the area encompassed by walls  20 ,  22 ,  24 , and  26 . However, mounting plate  16  may be of any suitable shape as long as it is generally the same shape and slightly larger than base  18 . Small tab slots  62  extend through mounting plate  16  near its periphery, and are sized to receive tabs  56  of walls  20 ,  22 ,  24 , and  26 . Rectangular tab slots  64  are slightly longer than slots  62 . Slots  64  surround reflector pattern  38  and receive and hold tabs  106  of reflector strip  40 . Screw holes  68  in mounting plate  16  also surround reflector pattern  38 , but are closer to reflector pattern  38  than slots  64 . Each reflector in reflector set  36  is mounted to reflector mounting plate  16  by screw holes  68  and screws  70 . Holes  72  at the edge of mounting plate  16  and screws  74  mount the optical housing to mounting housing  11 . 
     Reflector set  36  preferably comprises twenty reflectors  76 , as shown in FIG.  7 . Reflector set  36  is not limited to twenty reflectors and can contain any number of reflectors as long as the reflectors produce the desired light beam pattern. Each reflector  76  is a generally rectangular metal sheet tapered to a point at end  78 . As shown in FIGS. 1 and 3, end  78  is bent to an approximately ninety degree angle and is attached to reflector mounting plate  16  by hole  80  and screw  70 . Each reflector has a curved configuration to allow the proper reflective properties and has tab  84  extending from end  86 . Tab  84  is in the center of each edge  88  and is received within one tab slot  52  of base  18  holding end  86  of each reflector  76  in the proper reflector pattern. 
     Reflector set  42  preferably comprises eight reflectors  90 , as shown in FIG.  8 . Reflector set  42  is not limited to eight reflectors and can contain any number of reflectors as long as the reflectors produce the desired light beam pattern. Each reflector  90  is a trapezoidal planar metal sheet with tab  92  extending from edge  94  at an obtuse included angle, as shown in FIG.  1 . Each tab  92  has two screw holes  96  for mounting to base  18 . Screws  98  pass through holes  96  and threadably engage base  18  through holes  54 . Reflector set  42  forms a generally circular or octagonal pattern around hole  50 . 
     Reflector  44  is a metal generally faceted or frustoconically shaped reflector with hole  100  in the apex of the cone. As shown in FIGS. 3 and 9, reflector  44  has holes  102  in its side for mounting to bracket  46  by screws  104 . Reflector  44  is partially inserted into hole  50  with a portion of the reflector inside optical housing  12  and below base  18  tapering to a portion of the reflector outside of optical housing  12  and above base  18 . Hole  100  allows light source  48  to extend into the interior of optical housing  12 , with its base outside housing  12 . 
     Reflector strip  40  is a relatively long metal rectangular strip that extends perpendicularly from mounting plate  16  towards lens  13  when lens frame  14  is in a closed position, defining a space between strip  40  and lens  13 . Strip  40  reflects high angle light out of the optical assembly, making the light fixture more efficient. Tabs  106  extend from side  41  of strip  40  and are received in slots  64  of mounting plate  16 , coupling strip  40  to mounting plate  16 . Reflector strip  40  also has tab  108  and tab slot  110 . Tab  108  is inserted into slot  110  and holds strip  40  in a circular configuration around reflector pattern  38 . 
     Bracket  46  is a generally U-shaped metal bracket that is mounted to base  18  by holes  112  and screws  114 . As shown in FIGS. 4 and 11, bracket  46  has ends  116  and  118  that are each bent in two obtuse included angles creating a total bend of approximately ninety degrees. This total bend allows bracket ends  116  and  118  to be coplanar and adjacent to base  18 . Bracket  46  spans hole  50  and has holes  120  and  122  for mounting reflector  44 . Additionally, bracket  46  has holes  124  and  126  for mounting light mount  49 . 
     Cylindrical light mount  49  has a socket  49   a , is coupled to bracket  46  by screws  136 , and depends from the bracket towards reflector  44 . Light source  48  is coupled to light mount  49  by inserting light source  48  into socket  49   a  and vertically depends through hole  100  in reflector  44 . As shown in FIG. 1, light source  48  extends partially beyond reflectors  36 , allowing use of a less powerful light source than conventional light fixtures, while still producing the proper light beam configuration. The preferred power of the light source is either a 400 watt or 1000 watt metal halide lamp. It is possible to use a lower power light source if an extension is inserted. A less powerful lamp is generally shorter than the above mentioned lamps and since the placement of the light is critical, an extension would be required to allow the shorter, less powerful lamp to extend beyond the reflectors and produce the desired light beam configuration. 
     To assemble optical housing  12 , walls  20 ,  22 ,  24 , and  26  are folded along unitary fold lines  28 ,  30 ,  32 , and  34 , respectively. By folding each side to form a ninety degree angle with base  18 , each wall abuts the two walls adjacent to it, forming a square box. Reflector mounting plate  16  is coupled to walls  20 ,  22 ,  24 , and  26  by inserting tabs  56  into tab slots  62 , creating a ninety degree angle between each wall and reflector mounting plate  16 . Tabs  56  on each wall are then bent or folded over until each tab is parallel and rests against mounting plate  16 . Folding tabs  56  couples the base and walls with the mounting plate and requires that mounting plate  16  abut edge  60  of each wall. 
     Each reflector  76  of reflector set  36  is then vertically mounted to both the base and the reflector mounting plate. Tab  84  of reflector  76  is inserted into tab slot  52  holding reflector  76  in place and allowing end  86  of reflector  76  to abut the base. Optionally, tab  84  may then be bent over in the same manner as tabs  56 , coupling reflector  76  to base  18 . Screw  70  is inserted into hole  80  of reflector  76  and into screw hole  68  in mounting plate  16 , securing the reflector to the mounting plate. This procedure is repeated for each reflector in reflector set  36 . 
     As shown in FIG. 2, reflectors  90  are then mounted to base  18  in a circular or octagonal pattern around hole  50 . Each reflector  90  is mounted by screws  98  passing through screw holes  96  and into holes  54  in base  18 . Each tab  92  is parallel and adjacent to base  18 , causing each reflector  90  to extend toward the center of optical housing  12  and reflector  44  and away from base  18  at an acute angle. 
     Reflector strip  40  is coupled to mounting plate  16  by inserting tabs  106  into tab slots  64  which are then bent in the same manner as described above for tabs  56 . This causes strip  40  to abut mounting plate  16  for the entire length of edge  132 . Tab  108  is inserted into slot  110  assisting tabs  106  in forming a circular pattern for reflector strip  40 . 
     Bracket  46  is mounted to base  18  by screws  114 . Screws  114  pass through holes  112  and threadably engage holes  130  in base  18 . Reflector  44  is then mounted to bracket  46  by screw holes  120  and  122 . 
     Light mount  49  is mounted to bracket  46  by screws  136  passing through holes  124  and  126  and threadably engaging light mount  49 . Light source  48  is then inserted into light mount  49  and vertically extends through the center of reflector  44 , reflector sets  38  and  42 , and the center of optical housing  12 . This reflector pattern and light configuration forms a type V Illuminating Engineering Society (IES) beam distribution. 
     Referring to FIGS. 12-15, according to a second embodiment of the present invention, optical housing  202  is manufactured and assembled similarly to optical housing  12 . Optical housing  202  is comprised of base  204 , walls  206 ,  208 ,  210 , and  212 , and reflector mounting plate  214 , which are folded and coupled together as described above for optical assembly  12 . Reflector  44 , bracket  46 , and light source  48  are all assembled and mounted as described above. 
     Reflector set  216  is mounted similarly to reflector set  36 , but in reflector pattern  218 . Reflector set  216  is preferably comprised of sixteen individual reflectors identical to reflectors  76 . Reflector set  216  is not limited to sixteen reflectors and may be comprised of any number of reflectors that achieves the desired light beam configuration. Each reflector  76  of reflector set  216  is mounted to the base  204  and the reflector mounting plate in the manner described for reflector pattern  38 . As shown in FIG. 12, reflector pattern  218  has an open end  220 , in which no reflectors are mounted. Reflectors  232  and  234  abut edge  236  of reflector pattern  218 . In addition, reflectors  222  and  224  have respective edges  226  and  228  that are angled away from reflector strip  230  and towards light source  48 . Reflector pattern  218  generally forms a U-shaped pattern with reflectors  222  and  224  forming an indentation in the bottom of the U. 
     Reflector set  238  is mounted in a similar circular pattern to reflector set  42 . Each reflector in reflector pattern  238  is mounted to base  204  in the manner described for reflector  90 . However, as shown in FIG. 12, no reflector is mounted adjacent to reflectors  222  and  224 , creating an open ended semicircular pattern for reflector set  238  and making seven reflectors identical to reflectors  90 , the preferred number of reflectors. Reflector pattern  238  is not limited to seven reflectors and may be comprised of any number of reflectors that achieves the desired light beam configuration. 
     Reflector strip  230  is mounted to reflector mounting plate  214  in the same manner as reflector strip  40 . However, reflector strip  230  contours reflector pattern  218  and has an open end  240  and therefore does not engage itself. 
     The features of optical housing  202 , which are similar to optical housing  12  are identified with like reference numbers. The same description of those similar features is applicable. 
     This light reflector pattern and light configuration results in a type III IES beam distribution. Either of the above disclosed embodiments may be modified to form a type I or IV IES beam distribution. 
     Although the preferred material for the optical housing and reflectors is a metal, such as aluminum, the optical housing and reflectors can be modify by manufacturing each piece with vacuum metalized plastic. However, it would be necessary to use a modified lower wattage light source than the preferred 400 or 1000 watt, due to high heat possibly melting the plastic material. 
     While specific embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.