Abstract:
A down light fixture that is suitable for installation on building structures and around lawns and gardens of residential and commercial properties for providing aesthetically pleasing illumination and security illumination. The down light fixture includes a body having a hollow interior and a circuit board mounted in the hollow interior. A transparent cover extends across a lower end of the body. A wire extends through a pivotable mounting device secured to an upper end of the body and through a potting cup to the circuit board for carrying electrical power to a source of illumination. The body is formed with a drain port located so that any water that accumulates in the interior of the body when the body is in a downwardly directed orientation will drain from the body before it can reach an upper end of the potting cup.

Description:
FIELD OF THE INVENTION 
     The present invention relates to light fixtures, and more particularly, incandescent and LED light fixtures designed for installation on building structures and on other structures located around lawns and gardens of residential and commercial properties. 
     BACKGROUND OF THE INVENTION 
     Outdoor landscape lighting is popular for security, aesthetic, safety, and other reasons. For many years outdoor landscape light fixtures have incorporated incandescent light bulbs. Recent advances in light emitting diode (LED) technology have led to an increased demand for improved landscape light fixtures that utilize more reliable and more energy efficient high intensity LEDs. 
     Various types of commercial landscape light fixtures are available to meet the particular needs of residential or commercial properties. These include path, down, deck, tree, spot, spread, and security light fixtures. Down light fixtures, also referred to as “downlighting” or “moonlighting”, are outdoor landscape light fixtures that are designed to place the illuminating source above the target area. Down light fixtures can be used to illuminate specific garden elements for aesthetic appeal, or to illuminate pedestrian areas and large specific spaces for safety, security or recreational purposes. 
     Outdoor landscape light fixtures are exposed to rainfall and, not infrequently, to water sprayed by irrigation systems. Down light fixtures, as the name suggests, are pointed downwardly, and therefore have special waterproofing issues. 
     SUMMARY OF THE INVENTION 
     The present invention provides a down light fixture for installation on building structures and on other structures located around lawns and gardens of residential and commercial properties. The down light fixture includes a body having a hollow interior and a circuit board mounted in the hollow interior. A source of illumination is mounted on the circuit board. A pivotable mounting device is secured to an upper end of the body and is configured to enable directional orientation of the body. A potting cup inside the hollow interior extends between the pivotable mounting device and the circuit board. A transparent cover extends across a lower end of the body. A wire extends through the pivotable mounting device and the potting cup to the circuit board for carrying electrical power to the source of illumination. The body is formed with a drain port located so that any water that accumulates in the interior of the body when the body is in a downwardly directed orientation will drain from the body before it can reach an upper end of the potting cup. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric side elevation view of a down light fixture in accordance with an embodiment of the present invention. 
         FIG. 2  is a slightly reduced, exploded isometric view of the down light fixture of  FIG. 1 . 
         FIG. 3  is a longitudinal sectional view of the down light fixture of  FIG. 1 . 
         FIG. 4  is an enlarged isometric side elevation view of the cylindrical body of the down light fixture of  FIG. 1  with its knuckle joint assembly removed. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a down light fixture  10  in accordance with an embodiment of the present invention. The down light fixture  10  includes a cylindrical body  12  defining a hollow interior that encloses electrical components, a tapered shroud  14  slip fit and secured by a set screw  15  into a lower end of the cylindrical body  12  that directs and confines the emitted light, and a pivotable mounting device in the form of a knuckle joint assembly  16  attached to an upper end of the cylindrical body  12 . The foregoing components are preferably machined from cast Aluminum alloy parts for durability. An anodized coating is preferably applied to the exterior of the machined Aluminum alloy parts to prevent oxidation and to provide an aesthetically appealing finish. These components can also me made of other suitable metals such as brass alloy, Aluminum, Copper, etc. Some or all of them can be molded out of suitable plastic, however, a material with high thermal conductivity is preferred for the cylindrical body  12  so that this component can facilitate the dissipation of heat generated by the source of illumination contained therein. An upper segment of the exterior of the cylindrical body  12  is provided with an integral heat sink in the form of a plurality of spaced-apart radially and circumferentially extending ribs  12   a.    
     Referring to  FIG. 2 , a disc-shaped LED luminary printed circuit board (PCB)  18  is mounted inside the cylindrical body  12 . The luminary PCB  18  supports a high intensity LED  20  ( FIG. 3 ) and provides a conductive path to the electrical power. The luminary PCB  18  is readily replaceable in the event of a failure of the LED  20 . The down light fixture  10  may have a single LED and a PCB formed with electrically conductive paths for power connection and without other electronic components. Alternatively, the down light  10  may be of the intelligent LED type disclosed in U.S. patent application Ser. No. 12/564,840 filed Sep. 22, 2009 by Peter J. Woytowitz entitled “Low Voltage Outdoor Lighting Power Source and Control System” and published Apr. 8, 2010 under Publication No. US-2010-0084985-A1, or U.S. patent application Ser. No. 13/244,869 filed Sep. 26, 2011 by Peter J. Woytowitz entitled “Systems and Methods for Providing Power and Data to Lighting Devices,” now U.S. Pat. No. 8,278,845; the entire disclosures of which are hereby incorporated by reference. Said applications are assigned to Hunter Industries, Inc., the assignee of the subject application. The down light fixture  10  can have red, green and blue LEDs and can be connected to the aforementioned power source and control system in order to generate different lighting effects such as variable color and intensity in a reliable and energy efficient manner. 
     U.S. Publication &#39;985 provides examples of a power source and control system that rectify line voltage AC into a low voltage to be provided to a light fixture. For example, according to some embodiments, line voltage AC is rectified into a first high DC voltage. This first DC voltage is switched by a first switching circuit to create a high frequency AC voltage. The high frequency AC voltage is coupled through a transformer for isolation and step-down purposes. Because the frequency is high, the transformer is small and light compared to a 50/60 Hz transformer. The output of the transformer is rectified and filtered to produce a low voltage (12V) DC signal. The 12VDC signal is fed into a second switching circuit in the form of an H-bridge circuit that generates a low frequency AC signal with data periodically encoded at a high frequency. The low frequency AC signal is transmitted to the lighting fixtures via the buried power conductors. 
     As discussed in U.S. Patent &#39;845, a low voltage power signal between approximately 11VAC and 14VAC, or of approximately 12VAC, or of approximately 24VAC, may be used to power the down light fixture  10 . 
     Referring still to  FIG. 3 , a parabolic reflector  22  surrounds the LED  20  so that the LED  20  is located at the approximate focus of the reflector  22  which gathers and forwardly directs the light emitted by the LED  20  in a predetermined desired pattern to the target area. The inner end of the reflector  22  is secured to the cylindrical body  12  with a pair of machine screws  23   a  and  23   b  ( FIG. 2 ). The luminary PCB  18  is securely sandwiched between the reflector  22  and the cylindrical body  12  Referring to  FIGS. 2 and 3 , a disc-shaped color filter  24  and a disc-shaped diffuser  26  are mounted over the LED  20  and reflector  22 . The diffuser  26  softens the intensity of the light emitted by the LED  20  as perceived by an observer&#39;s naked eye. 
     An upper cylindrical segment  14   a  ( FIG. 3 ) of the shroud  14  removably slips into the lower segment  12   b  of the cylindrical body  12 . The female-to-male overlap of the lower body segment  12   b  with the upper cylindrical segment  14   a  of the shroud helps prevent entry of water into the cylindrical body  12 . Additionally, entry of water into the cylindrical body  12  is further impeded by a pair of O-rings  28  and  30  made of a suitable elastomeric material that are seated in annular grooves formed in the exterior of the upper cylindrical segment  14   a  of the shroud  14  and are squeezed between the cylindrical body  12  and the shroud  14 . The set screw  15  is threaded into a threaded hole  12   c  ( FIG. 4 ) that is formed in the lower body segment  12   b  and is tightened against an annular groove  14   e  formed on the outer surface of upper cylindrical segment  14   a  to hold the shroud  14  securely in position both axially and radially. 
     A disc-shaped protective transparent cover  32  extends across the diffuser  26  and provides an optical path for light to leave the down light fixture  10 . By way of example, the transparent cover  32  can be made of glass, high temperature resistant plastic, or scratch resistant sapphire. On one side of the transparent cover  32  a periphery of the transparent cover  32  engages the interior of a circular flange  14   b  that projects radially inwardly from the upper cylindrical segment  14   a  of the shroud  14 . A circular frame  36  supports the color filter  24 . The circular frame  36  carries the circular frame  34  and the diffuser  26 . The circular frame  36  and the color filter  24  are in turn supported by the reflector  22 . When the shroud  14  is screwed into the cylindrical body  12 , the shroud  14 , O-rings  28  and  30 , and the transparent cover  32  seal off a lower portion of the hollow interior of the cylindrical body  12  and protect the luminary PCB  18  and the LED  20 . 
     The knuckle joint assembly  16  ( FIG. 1 ) includes a base knuckle  16   a  and a top knuckle  16   b  that are pivotally connected by a machine bolt  34  ( FIG. 2 ). The male threaded distal end of the machine bolt  34  is screwed into a transversely extending female threaded sleeve  37  ( FIG. 3 ) formed in the top knuckle  16   b  to pivotally connect the base knuckle  16   a  and the top knuckle  16   b . The top knuckle  16   b  is secured to the upper end of the cylindrical base  12  with a pair of machine bolts  38  and  40  ( FIG. 2 ) that pass through a pair of side-by-side bores  42  formed in the top knuckle  16   b . The male threaded distal ends of the bolts  38  and  40  are screwed into axially extending female threaded sleeves  44  and  46  ( FIG. 4 ) formed in the top of the cylindrical body  12 . 
     The upper end of the cylindrical body  12  is formed with a circular mounting flange  12   d  ( FIG. 4 ) which mates with a shoulder (not visible) of the top knuckle  16   b  as best seen in  FIG. 3 . A pair of diametrically opposed slots  47   a  and  47   b  formed in the mounting flange  12   d  receive corresponding projections (not illustrated) on the top knuckle  16   b  to rotationally align the top knuckle  16   b  and the cylindrical body  12  during assembly. 
     An O-ring  48  ( FIG. 2 ) made of a suitable elastomeric material is seated in a pair of opposing circular grooves formed in the base knuckle  16   a  and the top knuckle  16   b . The O-ring  48  helps to seal the knuckle joint assembly  16  against the unwanted intrusion of water. A plurality of radially extending teeth  16   c  formed in the circular face surface of the top knuckle  16   b  mate with and fit between a plurality of radially extending teeth  16   d  ( FIG. 3 ) formed on the mating circular face of the base knuckle  16   a  to prevent unwanted slippage then the machine screw  34  is tightened. This arrangement permits the angle of the top knuckle  16   b  to be adjusted relative to the base knuckle  16   a  when the machine screw  34  has been loosened enough to allow the teeth  16   c  and  16   d  to pass by each other. 
     The base knuckle  16   a  and the top knuckle  16   b  are formed with recesses or grooves (not illustrated) that create a passageway. This passageway provides a conduit that allows a twin conductor insulated wire  49  ( FIG. 2 ) to pass through a hollow male threaded shank  50  of the base knuckle  16   a  and through the top knuckle  16   b . The wire  49  then passes through an axially extending cylindrical hollow potting cup  52  ( FIG. 4 ) formed in the cylindrical base  12 . The potting cup  52  is located inside the hollow interior of the cylindrical base  12  and provides a tubular conduit that extends between the knuckle joint assembly  16  and the luminary PCB  18 . The passageway that extends through the base knuckle  16   a  and the top knuckle  16   b  is dimensioned and configured to allow the wire  49  to traverse the interior of the knuckle joint assembly  16  without binding or chafing while still allowing the knuckle joint assembly  16  to be pivotally adjusted to change the angle of illumination provided by the down light fixture  10 . The proximal end of the wire  49  (not illustrated) extends a sufficient distance from the down light fixture  10  to facilitate operative connection of the conductors in the wires  49  to the terminals of the power source and control system. Additionally, the knuckle assembly  16  may be of the type found in U.S. Pat. No. 6,902,200 granted Jun. 7, 2005 to Joshua Beadle and entitled “Contaminant-Resistant Pivot Joint for Outdoor Lighting Fixture”, the entire disclosure of which is hereby incorporated by reference. The aforementioned patent is also assigned to Hunter Industries, Inc. 
     The male threaded shank  50  ( FIG. 2 ) of the knuckle joint assembly  16  can be screwed into a bracket (not illustrated) that can in turn be secured with wood screws or bolts to a beam or overhang of a building or to a structure such as a trellis or gazebo located in a lawn or garden. Typically the bracket would be secured to an overhead member so that the central longitudinal axes of the cylindrical base  12  and the shroud  14  are pointed in a downward direction. The down light fixture  10  can thus illuminate the target area below the down light fixture. The beveled lower portion  14   c  ( FIG. 1 ) of the shroud  14  is preferably oriented so that a peripheral oval-shaped lip  14   d  thereof faces downwardly. In the preferred orientation, a plane that passes through the peripheral lip  14   d  is substantially perpendicular to a plane normal to the axis of rotation of the knuckle joint assembly  16  defined by the bolt  34  ( FIG. 2 ). The set screw  15  ( FIG. 3 ) fixes the rotational position of the shroud  14  relative to the cylindrical body  12  when it is tightened. 
     The luminary PCB  18  ( FIGS. 2 and 3 ) has two conductive male pins made of metal that mate with corresponding metal contacts of a female electrical socket  56  ( FIG. 2 ) operatively connected to the distal end of the wire  49 . During assembly of the down light fixture  10  the wire  49  is potted inside the bore of the potting cup  52  with a predetermined quantity  57  of a suitable potting compound such as Part No. 041108-FC-4 from Ellsworth Adhesives. When the quantity of potting compound  57  cures, the potting compound  57  inside the potting cup  52  provides a substantially water tight seal between the wire  49  and an interior wall of the potting cup  52 . The wire  49  is permanently potted and sealed in an effort to prevent water intrusion from the upper end of the cylindrical body  12  into the lower portion of the interior of the cylindrical body  12  where it might reach the luminary PCB  18 , causing a short or damage to the LED  20 . The upper portion of the hollow interior of the cylindrical body  12  includes a reservoir or cavity  58  ( FIG. 3 ) through which the potting cup  52  extends. The cavity  58  is separated from the lower portion of the hollow interior of the cylindrical body  12  that contains the luminary PCB  18  by a transverse wall  60 . The lower end of the potting cup  52  is integrally formed with the transverse wall  60  and the bore that extends through the potting cup  52  communicates with a hole formed in the transverse wall  60 . This arrangement allows the electrical socket  56  to be pushed over the pair of metal pins that extend from the luminary PCB  18 . 
     Due to the normal inclined orientation of the down light  10  at a typical angle as illustrated in  FIG. 3 , a small quantity of water  62  can accumulate in the cavity  58 . A slot  64  ( FIG. 4 ) formed in the circular mounting flange  12   d  of the cylindrical body  12  provides a drain port. This drain port is rotationally oriented so that it is on the low side of the down light fixture  10 . The upper end of the potting cup  52  is higher in reference to the longitudinal axis of the down light fixture  10  than the drain port. The size of the drain port is sufficient so that the water  62  will always drain out of the cylindrical body  12  via the drain port before it reaches the upper end of the quantity of potting compound  57 . This prevents the water from standing on top of the potting compound  57  and seeping down through the potting cup  52  to the luminary PCB  18 . This is true even if the down light fixture  10  is mounted with its longitudinal axis completely vertical. 
     While an embodiment of a down light fixture has been described in detail, it will be understood by those skilled in the art, based on the description herein, that the present invention can be modified in both arrangement and detail. For example, the source of illumination could be an incandescent bulb instead of an LED. See U.S. Pat. No. 6,784,905 granted Apr. 5, 2005 to Joshua Z. Beadle or U.S. Pat. No. 7,387,409 granted Jun. 17, 2008 to Joshua Z. Beadle, the entire disclosures of which are hereby incorporated by reference. Said patents are also assigned to Hunter Industries, Inc. The down light fixture  10  could be designed to work with the lighting controller disclosed in pending U.S. patent application Ser. No. 13/189,718 filed on Jul. 25, 2011 by Peter J. Woytowitz entitled “Programmable Landscape Lighting Controller with Self-Diagnostic Capabilities and Fail Safe Features”, the entire disclosure of which is hereby incorporated by reference. Said application is also assigned to Hunter Industries, Inc. Therefore, the protection afforded the present invention should only be limited in accordance with the scope of the following claims.