Abstract:
An in-grade light fixture, comprising a below grade light fixture having a light opening substantially at grade level. An optical chamber is arranged within the light fixture housing and holding a light source generating light that passes through the light opening. A faceplate mechanism mounted over the light opening and to the optical chamber, and is held in place by mounting screws. The faceplate mechanism is at least partially rotatable over the light opening so that the location of said mounting screws can be adjusted around the light opening. An adjustment mechanism is included to adjust the height and angle of the faceplate mechanism to match the height and angle of the surrounding grade level and angle. A holding mechanism can also be included for holding the light fixture housing at the desired height within a hole prior to being buried. An anti-condensation valve can also be included on the optical chamber.

Description:
[0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 60/454,506 filed Mar. 13, 2003. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This invention relates to lighting fixtures and more particularly to in-grade lighting fixtures.  
           [0004]    2. Description of the Related Art  
           [0005]    Conventional in-ground or in-grade lighting fixtures are typically buried all or partially below ground level and include a light emitter that illuminates up from below ground level. They can be buried in the earth or covered by hardscape such as concrete, asphalt, wood, pavers, tile, etc. The fixtures are typically used to illuminate walls, columns, flags, trees, signs or a pathway.  
           [0006]    One type of in-grade lighting fixture generally comprises a housing and lens made of glass or other rigid and transparent material that is attached to an opening in the top of a housing. The housing contains various components including the light emitter that is arranged to emit light through the lens and electrical components that are used to power and operate the light emitter. When the light fixture is installed in-grade, the housing is typically below ground level and the lens is left uncovered so light can shine up through it. The electrical components can include a power supply, power converters, transformers, and mounting hardware for the light emitter. To hold all of these components, the housing can extend relatively deep into the ground (i.e. 14 to 16 inches).  
           [0007]    The housing can also include a light emitter mounting system that allows pivotal rotation of the light emitter within the housing without changing the angle of the lens. This allows the lamp to be aimed in directions other than straight up. This also allows the lamp to be configured to illuminate different types of architectural features or objects by adjusting the angle of illumination.  
           [0008]    During installation of these types of light fixtures, a hole is typically dug for the housing, the housing is placed in the hole and the hole is back filled around the housing. Any hardscape is then installed around the lens, leaving the lens uncovered. One disadvantage of these conventional light fixtures is that it can be difficult to arrange the housing in the hole so that it is level and the lens is at the proper height and angle. A misaligned or misplaced housing may not be discovered until after the hardscape has been installed. The only way to fix the arrangement of the housing is to remove the hardscape, dig out the hole around the housing and replace the housing in the hole in a better position. The hardscape can then be reinstalled.  
           [0009]    Conventional light fixtures have faceplates that are used to hold the lens on the housing, typically with screws. Lighting fixtures are often aligned in a row and after installation, the screw holes on the faceplates can be misaligned with the screw holes in the faceplates of adjacent lighting fixtures. The misaligned screw holes can be aesthetically undesirable and there is no mechanism for adjusting the faceplate holes in conventional light fixtures to align them with adjacent holes after the fixtures have been installed.  
           [0010]    Another disadvantage of conventional in-grade lighting fixtures is that it is difficult to properly arrange the fixtures such that the faceplate is level and at the appropriate height prior to backfilling. This can often be a trial and error process of first placing the fixture in the hole and determining if the faceplate is at the right level. If it is too high, the dirt below can be dug out and if it is too low, dirt, bricks or rocks can be placed under it. The fixture is then placed back in the hole to determine if the faceplate is in the desired location. This process is typically inaccurate, time consuming and inconvenient.  
           [0011]    In-grade light fixtures can have an optical chamber that contains the light emitter (lamp), with the optical chamber arranged in the housing so that light from the lamp emits through an upper housing opening. One disadvantage of conventional optical chambers is that condensation can develop inside the chamber through the heating and cooling of the lamp. Also, when the lamp needs replacement or the optical chamber needs servicing, the housing faceplate is usually removed and the interior of the chamber is accessed from the above grade level. During maintenance, dirt and debris can enter the chamber from above and can result in reduced life and ineffective performance of the lamp and chamber.  
         SUMMARY OF THE INVENTION  
         [0012]    The present invention seeks to provide an improved in-grade light fixture that solves the problems of conventional light fixtures. One of the features of an improved light fixture according to the invention comprises a faceplate mechanism for adjusting the level and angle of the faceplate after the light fixture hole has been backfilled and the desired hardscape has been installed. One embodiment of a faceplate mechanism according to the present invention comprises a plurality of adjustment posts arranged around an opening in the housing. The faceplate is arranged over the opening, on the adjustment posts. The height of each of the adjustment posts can be individually raised or lowered to raise and lower the faceplate, or to adjust its angle. The faceplate is also rotatable to adjust the orientation of the screw holes for their alignment with holes on adjacent light fixtures.  
           [0013]    A lighting fixture according to the present apparatus also comprises a holding apparatus for holding the light fixture housing at the desired height and angle in a hole, prior to backfilling the hole. One embodiment of a holding apparatus according to the present invention comprises a mounting shelf around the light fixture body that has holes, each of which is sized to receive a mounting member, such as PVC pipe. Each pipe can slide within its respective hole and each of the holes has a mechanism for affixing the hole to the pipe at a desired location along its length.  
           [0014]    The invention also provides an optical chamber anti-condensation valve that helps eliminate condensation in the optical chamber. One embodiment of a valve according to the present invention allows air to escape from the optical chamber when the pressure increases inside the chamber, but does not allow air to flow into the chamber when the inside pressure drops. Instead, when the pressure drops a vacuum is created in the chamber that does not allow the formation of condensation in the chamber. The vacuum also allows the faceplate and optical chamber to be removed from the housing as a unit so that the chamber can be serviced from above ground level. This reduces the chances that dirt and debris will be introduced into the chamber, or onto sealing surfaces.  
           [0015]    These and other further features and advantages of the invention will be apparent to those skilled in the art from the following detailed description, taken together with the accompanying drawings, in which: 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is an elevation view of one embodiment of a lighting fixture according to the present invention;  
         [0017]    [0017]FIG. 2 is a exploded perspective view of one embodiment of a lighting fixture according to the present invention;  
         [0018]    [0018]FIG. 3 is a sectional view of one embodiment of a faceplate mechanism according to the present invention;  
         [0019]    [0019]FIG. 4 is an elevation view of one embodiment of an optical chamber according to the present invention;  
         [0020]    [0020]FIG. 5 is a perspective view of the optical chamber in FIG. 4;  
         [0021]    [0021]FIG. 6 is an exploded perspective view of one embodiment of the patented chamber valve according to the present invention; and  
         [0022]    [0022]FIG. 7 is a sectional view of the patented chamber valve of FIG. 6. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0023]    Faceplate Mechanism  
         [0024]    [0024]FIGS. 1 and 2 show one embodiment of a lighting fixture  10  according to the present invention, having a faceplate mechanism  11  and a mounting shelf  13 . The faceplate mechanism  11  is sized to mount over the top circular opening  15  in the light fixture housing  16  and allows the height and angle of a faceplate  18  to be adjusted to compensate for any misalignment between the faceplate  18  and the surrounding finished surface of the ground and/or hardscape. The faceplate mechanism  11  also allows for adjustment of the faceplate screw holes  26  so that they can be aligned with the screw holes of adjacent lighting fixtures. The mounting shelf  13  allows the housing  16  of the lighting fixture  10  to be more easily and accurately arranged within a hole before backfilling to reduce the chances of misalignment during installation.  
         [0025]    Referring to FIGS. 2 and 3, the faceplate mechanism  11  generally comprises a faceplate  18 , leveling collar  20 , nut ring  22 , mounting screws (not shown), and adjustment posts  24 . When the faceplate mechanism  11  is assembled, the leveling collar  20  is held onto the adjustment posts  24  by the jam nuts. The faceplate  18  comprises a circular faceplate casting  18   a  that holds a circular lens (not shown) within it, with an airtight and watertight seal between the casting  18   a  and the lens. The faceplate  18  can be different sizes and the faceplate casting  18   a  can be made of different materials such as cast 360 aluminum, brass, or stainless steel, all of which can be painted different colors. The lens can be made of any rigid and transparent material such as tempered borosilicate glass, and should be thick enough to withstand the weight that may be placed on it, for example, by foot or vehicle traffic.  
         [0026]    The faceplate  18  has four equally spaced faceplate holes  26 , although in other embodiments more or less holes can also be used. Each of the holes  26  aligns with one of four collar slots  28 , and also aligns with one of four nut ring holes  30 . Each mounting screw is inserted into a respective one of the four faceplate holes  26  and each screw passes through a respective aligned collar slot  28 . Each of the nut ring holes  30  can be threaded to mate with the threads on the mounting screws. In alternative nut ring embodiments, such as shown in FIG.1, the nut ring  22  may be too thin to be effectively threaded and alternative mechanisms are needed to provide the threads to mate with the mounting screws. One of these alternative mechanisms is a cage nut that is mounted in the square nut ring holes. Other mechanisms include a pem nut or avdel nut, each of which can be inserted into a respective nut ring hole  30 .  
         [0027]    The nut ring can be made of different materials, with a suitable material being stainless steel. The leveling collar can be made of the same materials as the faceplate. The faceplate  18 , leveling collar  20  and nut ring  22  can have different diameters depending on the size of the housing opening  15 , with a suitable diameter for each being approximately, 10¾, 11¼ and 11 inches respectively.  
         [0028]    When each of the mounting screws is inserted into the aligned faceplate hole  26  and collar slot  28 , and tightened in a respective nut hole  30 , the leveling collar  20  is held firmly between the nut ring  22  and the faceplate  18 . Different types of mounting screws can be used with the preferred screws being captive screws, which are known in the art. The head of each captive screw is retained within its faceplate hole  26  when the screws are unscrewed from the nut ring holes  30 . This prevents the screws from falling out of the faceplate holes during maintenance of the light fixture  10 .  
         [0029]    The leveling collar  20  has four collar holes  32  each of which aligns with one of four nut ring slots  34 , although more or less holes  32  and slots  34  can also be used. Each of the four adjustment posts  24  has a threaded top section  38 , a wider section  40  and a threaded lower section  42 . Each lower section  42  is threaded to mate with one of four threaded post holes  44  that are equally spaced around the housing&#39;s top circular opening  15 . The post holes  44  are aligned with the collar holes  32  and when the posts  24  are mounted in the post holes  44 , the top section  38  of each post  24  passes through its respective collar hole  32 . Each top section has an upper slot that allows each of the posts  24  to be turned using a screwdriver when the leveling collar  20  is in place over the posts  24 .  
         [0030]    Each wider section  40  is rounded slightly on top and the bottom surface of each collar hole  32  is also rounded to match the wider section&#39;s top surface. When the leveling collar is in place, it rests on the wider sections  40  with the only contact between the leveling collar and the remainder of the fixture  10  below is its contact with the posts  24 . Each of the wider sections  40  also fits closely within one of the four nut ring slots  34 . When the mounting screws are turned into the nut ring holes  30  to mount the faceplate  18  (as described above), the nut ring  22  is arranged in a slot  28  in the bottom of the leveling collar  20  (as best shown in FIG.3).  
         [0031]    A circular clearance cavity  50  is included around the housing opening  15 , outside the post holes  44 , and is arranged so that the lower portion of the adjustment collar  20  can pass into the cavity  50  when the collar  20  is lowered on the posts  24 . The cavity  50  gives additional range to the lowering of the collar  20  by allowing the lower portion of the collar  20  to pass below the upper surface of the housing  16 . Different ranges of adjustment can be provided for the faceplate mechanism  11 , with a typical range being ¼ of an inch up and down from a medium position.  
         [0032]    In operation, each of the adjustment posts  24  is mounted in a respective one of the four post holes  44 , and the adjusting collar and attached nut ring is placed over posts  24 . The leveling collar  20  is then placed on the adjustment posts  24 , with the upper section  38  of each post passing through a respective collar hole  32  and the collar resting on the wider sections  40  of the posts  24 . The fixture  10  is then placed in a hole, the hole is backfilled, and any desired hardscape is installed.  
         [0033]    The protective cover can then be removed to allow an optical chamber to be installed as more fully described below. However, before installing the optical chamber, the height and angle of the leveling collar  20  can be adjusted to match the level of the surrounding grade or hardscape by turning the desired posts  24 . The posts  24  can be turned while the collar  20  is in place by a screwdriver turning the post upper portions  38  that extend through the collar holes  32 . If the level of the collar  20  is to be lowered, the posts  24  are turned further into the post holes  44 . If the level is to be raised, the posts  24  are turned out of the post holes  44  so that they extend further from the holes. To adjust the angle of the collar, the height of fewer than all of the posts  24  can be adjusted appropriately. When the collar  20  is in its desired position, it can be locked in place by locking jam nuts that can be turned and tightened on the threaded upper section  38  so that part of the collar  20  is sandwiched between each of the nuts and its respective post upper section  40 .  
         [0034]    [0034]FIGS. 4 and 5 show one embodiment of optical chamber  60  according to the present invention that can be installed in the housing  16  after the collar  20  is properly adjusted. The body  62  is sized to fit through the collar  20 , nut ring  22  and housing opening  15 , and has a flange  64  that rests on an inside ledge  66  on the collar  22  (shown in FIGS. 2 and 3). The optical chamber  60  is arranged inside the housing  16  with the light emitter (lamp)  68  directed up. Other optical chambers according to the present invention can house different types of emitters, including but not limited to light emitting diodes, lasers, fluorescent lights, etc., each of which can be arranged in many different ways within the chamber. The optical chamber  60  also comprises a mounting system  69  that allows the lamp  68  to pivot to adjust the direction of lamp illumination without changing the position or angle of the faceplate  18  or collar  20 . A circular silicon gasket  70  is positioned on the top outside diameter, and bottom surfaces of the flange  64  and the faceplate  20  is placed on the collar  20 . When the mounting screws are tightened into the nut ring holes  30  the faceplate casting  18   a  compresses the gasket  70  providing an airtight and watertight seal between the faceplate  20  and flange  64 .  
         [0035]    When a plurality of light fixtures  10  are installed in a row, it is aesthetically important for the faceplate holes  26  in one fixture  10  to align with the holes in adjacent installed fixtures  10 . To make this adjustment, after the fixtures  10  have been installed, the mounting screws can be partially loosened in the faceplate holes  26  with the mounting screws still threaded in their respective nut ring holes  30 . The faceplate  18  and nut ring  22  remain connected together by the mounting screws and can be rotated as a unit. The leveling collar  20 , however, is held in place by the adjustment posts  24 . The faceplate  18  and nut ring  22  combination can be rotated left or right to adjust the orientation of the faceplate holes  26 . During this rotation, the mounting screws slide within the stationary collar slots  28  and the stationary mounting posts  24  slide within the rotating nut ring slots  34 . The amount of the faceplate rotational adjustment is limited by the length of the collar slots  28  and nut ring slots  34 . After the faceplate holes  26  have been aligned with the holes in adjacent lighting fixtures  10 , the mounting screws can be tightened to hold the faceplate  18  and nut ring  22  in position.  
         [0036]    Mounting Shelf  
         [0037]    Referring again to FIGS. 1 and 2, the housing  16  also has an axial mounting shelf  13  located above the housing&#39;s mid-section that is used for conveniently and accurately mounting the lighting fixture  10  in a hole so that it is level and at the appropriate height. The shelf  13  is generally horizontal and has four equally spaced holes  102 , with each hole having one of four upwardly extending hole sleeves  104 . The shelf  13  extends around nearly the entire housing  16 , with its only interruption being a splicing compartment  101  that is arranged for splicing incoming power to the lighting fixture lamp.  
         [0038]    The holes  102  and sleeves  104  have the same diameter and are sized to accept an elongated stilts  105 , such as standard PVC pipe. Alternative holes and sleeves can have different diameters to accept different sizes of PVC pipe or different elongated stilts, and the hole and sleeve cross-section can have different shapes such as square, rectangle, oval, etc.  
         [0039]    The PVC pipe can be mounted within each of the holes using many different mounting methods, including but not limited to gluing, welding, clamping or crimping. In a preferred mounting method each pipe is held in the sleeve  104  by a sleeve mounting screw. Each sleeve  104  has longitudinal crease  106  on its outside surface for a screw to turn into the sleeve  104  and fix the sleeve  104  to PVC pipe inserted therein. The crease  106  is designed to accept a standard “TEK screw”, although other screws can also be used. The screw can be turned partially through a respective sleeve  106  at the crease, which causes the sleeve  104  to bulge toward and hold the PVC pipe. Alternatively, the screw can be turned through the sleeve  104  and into the PVC pipe to hold it in place.  
         [0040]    In one method of using the mounting shelf  13  and PVC pipe according to the invention, the light fixture  10  is placed in a hole. Separate pieces of PVC pipe are then inserted into the holes  102  and sleeves, with each of the pipes being long enough that their lower end rests on the surface of the ground at the base of the housing  16  and their upper end extends through and above the top of its respective sleeve  104 . The lower end of each of the PVC pipes is then forced into the ground, preferably by hammering on each pipe&#39;s upper end. The pipes should be pounded in far enough so that they can support the weight of the lighting fixture  10 . The lighting fixture can then be slid up and down on the PVC pipes until it is at the desired height and angle. Tech screws can then be inserted into the sleeve creases to hold the light fixture  10  at its location so that the light fixture  10  is then held above the ground on the PVC pipes. The hole can then be backfilled and leveled around the protective cover and any desired hardscape can be installed.  
         [0041]    The bottom surface of the shelf  13  also comprises rebar clips  108  that are arranged to rest on rebar in those installations where rebar is used to reinforce the hardscape. When the clips are placed on the rebar, a tie wire can be fed through the rebar hole  109  adjacent to the clip, wrapped around the rebar, and fed back through the rebar notch  110 . The ends of the tie can then be knotted together to hold the sleeve  13  to the rebar. This clip and tie arrangement holds the fixture in place during installation of the hardscape. The angle and level of the faceplate  18  can then be adjusted as described above.  
         [0042]    Chamber Valve  
         [0043]    Referring to FIGS. 4 and 5, the optical chamber  60 , as described above further comprises a valve  120  arranged at the bottom of the body  62 , although the valve may be arranged in other locations. The valve  120  is designed and positioned to allow air to pass out of the body when pressure builds up in the chamber  60 , and to block ambient air from passing back into the chamber  62 .  
         [0044]    When the chamber  60  is installed in the housing  16  and the faceplate mechanism  12  is mounted in place, a seal is created between the faceplate  18  and the flange  64 . The chamber  60  is sealed from the ambient and the only way for air to pass out of the chamber  60  is through the valve  120 . During operation of the lamp  68 , air within the chamber is heated, which causes the air to expand and air pressure to build within the chamber  60 . As the pressure builds, air passes out of the valve  120 . When the lamp  68  is not operating, the air within the chamber  68  cools, but no air is allowed to pass back into the chamber  62  through the valve  120 . This results in the formation of a negative air pressure, or vacuum, within the chamber  62 . This negative air pressure has the benefit of preventing condensation within the chamber.  
         [0045]    This negative air pressure provides an additional benefit during the maintenance of the light fixture  10 . When replacing the lamp  68  or conducting other maintenance on the chamber  62 , the interior of the chamber must be accessible. As described above, in conventional light fixtures, the faceplate is removed and the interior of the chamber is accessed from above, which presents a danger that dirt or other debris can enter the chamber.  
         [0046]    The negative air pressure (approximately 160 pounds) in the chamber  60  results in the faceplate  18  being held to the flange  64  such that the faceplate  10  and chamber  60  form a single unit. Accordingly, as the faceplate  18  is removed from the housing  16 , the chamber  60  is removed with it. To remove the faceplate  18  from the chamber  60 , the chamber&#39;s negative air pressure can be reduced by pressing the air release button  122  that extends from the bottom of the valve  120 . This allows air to flow back into the chamber to reduce the pressure until the faceplate  18  can be easily removed.  
         [0047]    By removing the faceplate  18  and chamber  60  as a unit, the lamp replacement (or other maintenance) can be conducted above ground level where there is a reduced chance that dirt or other debris would enter the chamber  60 . When conducting maintenance on a plurality of light fixtures, each of the faceplate  18  and chamber  60  units can be removed and taken to a clean work area for maintenance. This would further reduce the chance for dirt or debris to enter the chamber  60 .  
         [0048]    [0048]FIGS. 6 and 7 show the valve  120  in more detail, which comprises a housing  130  that has mounting threads on its lower/narrower section  134 . The lower section  134  is inserted into a hole at the bottom of the chamber  60  with the housing primarily within the chamber  60  and the lower section  134  extending from the bottom of the chamber  60 . A nut (not shown) is mounted to the portion of the lower section  134  that extends from the chamber  60  and is tightened to mount the housing  130  in place. An O-ring  133  is mounted to a housing O-ring groove  135  to provide an air and watertight seal between the housing  130  and chamber  60 .  
         [0049]    A spool  136  and the button  122  are arranged within a longitudinal cavity in the housing  130 . A narrow button section  140  is threaded to mate with the threads on the inside of the wider spool section  142 . An O-ring  143  is provided between the two to provide an airtight seal. When installed, the spool  136  and button  122  operate as a single unit. The narrow spool section  144  extends from the housing  134  and a spring  146  is included that biases the spool  136  toward the bottom of the chamber  60 . The spool  136  is prevented from fully extending into the housing  134  by an E-ring  148  that is mounted in an axial groove  149  at the end of the spool  136 .  
         [0050]    The spool  136  and the button  122  each have a passageway  150 ,  152  down their longitudinal axis, that align down the housing&#39;s longitudinal axis when the spool  136  and button  122  are mounted together as a unit in the housing  130 . The aligned passageways  150 ,  152  allow air to pass freely between the chamber and the ambient outside the chamber  60 . However, a duckbill valve  151  is arranged within the button&#39;s narrow section  140  between the aligned passageways  150 ,  152  so that air passing from the chamber  60  passes through the duckbill valve  151 . The duckbill valve has a slit  153  that remains closed unless there is positive pressure from within the chamber  60 . The positive pressure passes through passageway  150 , and into the duckbill valve  151  causing the slit  153  to open and the positive pressure to dissipate to the ambient through passageway  152 . This pressure dissipation occurs during operation of the lamp  68 , when pressure builds within the chamber. However, after operation of the lamp stops and the chamber is cooled, a vacuum is created in the chamber by the duckbill valve  151  preventing the higher pressure ambient air from passing into the chamber  60 .  
         [0051]    When removing the faceplate  18  from the chamber  60 , the vacuum is released by pressing the button  122  as described above. This action causes the button  122  and spool  136  to slide within the housing cavity against the bias of the spring  146 . Air ports  154  are included in the housing  130  to provide air passageways from the interior of the chamber into the cavity of the housing  130 . During normal operation, the passageway is blocked from the ambient by the spool  136 , button  122 , and a button  0 -ring  156  that is mounted in a button O-ring groove  158  to provide a seal between the button  138  and the surface of the housing cavity. However, as the spool  136  and button  122  slide toward the interior of the chamber, the  0 -ring  156  passes the air ports  154 , which allows air to flow into the chamber through the spacing  160  between the button  138  and the interior of the housing cavity and into the air ports  154 . This allows for air to enter the chamber to reduce/eliminate the vacuum.  
         [0052]    When the button  138  is released, the bias of the spring  146  causes the spool/spring combination to slide back to its position as shown in FIG. 7. In this position the only path for air to leave the chamber is though the slit in the duckbill valve.  
         [0053]    Although the present invention has been described in considerable detail with reference to certain preferred configurations thereof, other versions are possible. Therefore, the spirit and scope of the invention should not be limited to the preferred versions in the specification.