Abstract:
A universal mounting supports high intensity LEDs in a lighting fixture with heat removal and electrical connection facilities. A holder includes a peripheral sidewall defining a cavity for accepting a printed circuit board assembly. A support member supports the printed circuit board assembly along the peripheral sidewall. Electrical contact elements are provided the printed circuit board. A thermal conduction member is in thermal communication with the printed circuit board assembly. The receptacle portion removably engages with the holder portion. A plurality of contact sockets conductively engages the electrical contact elements of the holder portion to interconnect the contact elements to external wires. An aperture in the receptacle portion accepts the thermal conduction member, wherein the thermal conduction member passes through the aperture and into a space for dissipating heat from the printed circuit board.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention is directed to electronic components, and more particularly to a universal holder assembly for light emitting diodes (LEDs). 
       BACKGROUND 
       [0002]    The use of high intensity LEDs for general-purpose illumination, and in specialty lighting applications such as architectural and video display applications, has increased in recent years. Typically, manufacturers of LED lighting assemblies design assemblies that are customized for the specific LED devices that are used in the illuminated displays. The electrical interconnections and thermal characteristics of the assemblies are often treated as secondary issues, and dealt with separately from the mechanical and esthetic aspects of the lighting fixture. This frequently results in thermal and interconnection problems with the LED assembly packaging. The heat accumulation may damage the LEDs themselves, resulting in shorter useful life of the LEDs, or cause damage to the light fixture housings such as warping and discoloration. 
         [0003]    What is needed is a standard holder for high-intensity LEDs that integrates electrical and thermal connections in a single receptacle. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments that fall within the scope of the claims, regardless of whether they accomplish one or more of the aforementioned needs 
       SUMMARY OF THE INVENTION 
       [0004]    In one aspect, the present invention is directed to a universal mounting assembly. The mounting assembly supports high intensity LEDs in a lighting fixture. The mounting assembly includes a holder portion and a receptacle portion. The holder portion includes a peripheral sidewall defining a cavity for accepting a printed circuit board assembly. A support member is disposed along the peripheral sidewall to support the printed circuit board assembly. A plurality of electrical contact elements are provided for connecting LEDs mounted on the printed circuit board. A thermal conduction member is configured to thermally communicate with the printed circuit board assembly. The receptacle portion is configured to removably engage the holder portion. The receptacle portion has a plurality of contact sockets configured to conductively engage the plurality of electrical contact elements of the holder portion, to interconnect the plurality of contact elements to external wires of the light fixture. An aperture is arranged in the receptacle portion to accept the thermal conduction member; wherein the thermal conduction member passes through the aperture and into a space for dissipating heat from the printed circuit board. 
         [0005]    In another embodiment, the present invention is directed to a universal mounting assembly for supporting high intensity LEDs in a lighting fixture. The mounting assembly has a holder portion with a peripheral sidewall defining a cavity for accepting a printed circuit board assembly. At least one support member is disposed along the peripheral sidewall to support the printed circuit board assembly containing LEDs. A plurality of electrical contact elements is provided within the holder portion to connect to external wires of the light fixture. A thermal conduction member is in thermal communication with the printed circuit board assembly. An aperture in the holder portion is arranged to accept the thermal conduction member. The thermal conduction member passes through the aperture and into a space for dissipating heat from the printed circuit board. 
         [0006]    In another embodiment, the present invention is directed to a mounting assembly for supporting at least one high intensity LED in a lighting fixture. The mounting assembly has a first portion and a second portion. The first portion includes a frame portion and a plurality of integral electrical conductors. The integral electrical conductors are arranged about a perimeter of the frame for connection to corresponding electrical contact pads disposed on a PCB. At least one high intensity LED is mounted on the PCB. The second portion is retentively engageable in thermal contact with the first portion. The second portion extends axially from the first portion for dissipation of heat from the PCB disposed within the first portion. The second portion has a cavity to connect it to the first portion, and has at least one base portion of the second portion to support the first portion within the cavity. 
         [0007]    Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is an exploded view of an LED connector assembly holder and socket connector. 
           [0009]      FIG. 2  is a cross-sectional view of the assembled holder and socket connector. 
           [0010]      FIG. 3  is a top plan view of the holder. 
           [0011]      FIG. 4  is a cross-sectional view of the holder taken along the lines  3 - 3  in  FIG. 2 . 
           [0012]      FIG. 5  is a bottom plan view of the holder. 
           [0013]      FIG. 6  is a cross-sectional view of an alternate embodiment of the holder. 
           [0014]      FIG. 7  is a cross-sectional view of another alternate embodiment of the holder. 
           [0015]      FIG. 8  is an alternative embodiment of the LED connector assembly mounted on a PCB. 
           [0016]      FIG. 9  is a socket connector mounted on a PCB. 
           [0017]      FIG. 10  is an exploded view of an alternate embodiment. 
           [0018]      FIG. 11  is a partial sectional view of the alternate embodiment of  FIG. 10 . 
       
    
    
       [0019]    Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    The present invention is a universal LED connector assembly that accepts a conventional LED printed circuit board (PCB) containing at least one high intensity LED. The PCB can be of conventional construction, or may include thermally conductive cladding such as aluminum. Each LED circuit board represents a component or pixel of a larger image or light source. The LED connector assembly is designed to be independent of the actual LED device that is used. The LED PCBs are for use in various architectural and general-purpose lighting fixtures, signs and video displays, traffic signals and various other applications using high intensity LEDs. The lighting fixture typically provides a housing or structure that supports the LED light source. The structure provides power connections to the LED light source, and provides openings through which the light shines when the light source (or sources) is energized. When used herein, the word lighting fixture is meant to include all general and specific-application LED devices that employ high intensity LEDs, and not limited to lighting fixtures for building illumination. Examples of lighting fixtures include track mounted spotlights utilizing incandescent bulbs, and walkway lights using incandescent or halogen bulbs. 
         [0021]    Referring to  FIGS. 1-5 , an LED connector assembly  10  includes a holder portion  12  and a connector portion  14 . The holder portion  12  removably engages the connector portion  14  by inserting contact pins  22  (see, e.g.,  FIG. 4 ) into sockets  24 . An LED PCB assembly  16  is rigidly supported in a recess  26  of the holder portion. The LED PCB assembly  16  has at least one LED  28  mounted thereon, but may include several LEDs if desired. For example, a common configuration for the LED PCB assembly includes three LEDs of red, green and blue (RGB) light for controllably varying the combinations to create virtually any color light. For each color another contact pair is required in the socket. For example, and RGB will require six individual contacts arranged around the outside of the LED PCB. 
         [0022]    A heat sink  18  is supported within the holder portion  12  by an internal support ring  42 , and is retained in position by a circular locking clip  30  or other similar spacer. The heat sink  18  contacts the bottom side of the LED PCB assembly  16  and extends downward below the bottom edge  32  of the holder portion  12 . The heat sink  18  extends into and through the connector portion  14  when the holder portion  12  is engaged, and provides a thermal path for dissipating heat generated by the LED PCB assembly  16 . The heat sink may be constructed of any suitable thermal conductor. By way of example and not by limitation, the heat sink material may be copper, aluminum or die-cast zinc. In an alternate embodiment, the heat sink  18  may also be a heat pipe. In the drawings the heat sink  18  is shown as a generally circular cylinder with a flat circular head portion  58 , however, the shape may vary depending on the application to provide additional exposed surface for heat dissipation. For example, the heat sink  18  may include heat fins, fluting, or other shapes for increased heat dissipation, as will be readily appreciated by those persons skilled in the art. Thermally conductive grease or thermally conductive pad may be applied to the flange or head portion  58  to promote the transfer of heat from the LED PCB  16 . 
         [0023]    The LED PCB assembly  16  preferably snaps into position in the holder portion  12  and is retained by angled tips  60  of contact fingers  34  connected to contact pins  22 . The contact fingers  34  and contact pins  22  provide electrically conductive paths to lead wires  36   a - 36   d , through contact sockets  24 . A spring  38  applies compressive force between the heat sink  18  and the bottom of LED PCB assembly  16 , while simultaneously applying a normal force to the contact fingers  34 . A washer  40  rests on the locking clip  30  and retains the spring  38  in position between washer  40  and LED PCB assembly  16 . 
         [0024]    Referring to  FIG. 3 , one or more LEDs  28  are electrically connected through the PCB assembly  16  to electrical interconnection pads  44  (See, e.g.,  FIG. 3 ) disposed at the periphery of the PCB assembly  16  and aligned with the contact fingers  34  for locking engagement. There are two interconnection pads  44  required for each LED that is mounted on the LED PCB assembly  16 . In the exemplary embodiment illustrated in  FIG. 3 , two LEDs can be accommodated by the four interconnection pads  44  shown, although the PCB assembly  16  that is depicted includes only a single LED. More interconnection pads  44  may be added as required to accommodate the total number of LEDs. Likewise, the number of contact fingers  34  and sockets  24  must correspond with the number of interconnection pads  44 . The number of contacts that may be arranged around the periphery is only limited by the geometry of the PCB assembly  16 . Additional interconnects may be used for communications or control wiring for one or more LED fixtures (not shown). A typical LED PCB assembly includes an LED light source mounted on a composite substrate of an electrically insulating top layer, e.g., FR4 or micarta board, optionally including a metallic bottom layer for improved heat conduction, e.g., aluminum or copper. Bayonet lugs  20  are optionally formed on the holder portion  12  for attachment of the LED connector assembly  10  to a customer&#39;s light fixture lens assembly, or other structure into which the LED connector assembly is to be mounted. Alternate attachment means for the LED connector assembly may include threaded connections or snap-fit connections (not shown). 
         [0025]    In another embodiment shown in  FIG. 6 , the heat sink  18  may be retained within the holder portion  12  by a molded shelf portion  46  of the internal support ring  42 , replacing the locking clip  30  and washer  40  in the embodiment described above. Another arrangement for maintaining the position of the heat sink  18  is shown in  FIG. 7 . In this arrangement, a latching edge  48  engages with a rim portion  50  of the heat sink  18 . The rim portion  50  is maintained against the latching edge  48  by spring  38 . This arrangement has fewer parts by eliminating, for example, the washer and clip, and is therefore easier to assemble and to integrate into a lighting fixture. The PCB assembly floats between the contact fingers  34  and the heat sink  18 . The contact fingers  34  apply downward force and the heat sink  18  applies opposite force to maintain the LED PCB assembly  16  in position, i.e., the heat sink  18  pushes upward against the LED PCB assembly  16 . 
         [0026]    The connector portion  14  may optionally be eliminated within the scope of the invention. Referring again to  FIG. 4 , the contact pins  22  may be eliminated and replaced with solder tails or press fit tails snap-in connectors. This would eliminate the need for a connector portion  14 , which may be replaced by a substrate  52  (see, e.g.,  FIG. 8 ), by direct attachment to another PCB (not shown) or left unsupported. In the embodiment shown in  FIG. 8 , the alternate LED connector assembly  10   a  includes the PCB holder portion  12  mounted on a substrate  52 , either by soldering or mechanical fasteners. A plurality of connector terminal portions  54  extends from the holder portion  12  through the substrate. External wiring (not shown) is connected to the connector terminal portions  54  to power the LEDs and any associated control or communications devices of the light fixture or device into which the LED connector assembly  10  is fastened. The heat sink  18  also protrudes below the substrate  52  and is exposed to an air space below for dissipating heat. The air space may include airflow driven by a fan to supplement or enhance the heat dissipation characteristics of the heat sink  18 . The LED PCB assembly  16  snaps into position in the holder  10   a.    
         [0027]    Referring next to  FIG. 9 , the connector portion  14  may optionally be mounted on a substrate  52 , and the holder portion  12  plugged into the connector portion  14 , with terminal portions  54  extending from the opposite side of the substrate  52 , and heat sink  18  protruding below the substrate as described above. 
         [0028]    Referring next to  FIGS. 10 and 11 , an alternate embodiment of the LED connector assembly  10  has a modified heat sink  18  with a fluted shape that provides additional surface area for dissipating heat. In one embodiment, the heat sink  18  is designed with a complementary outer ring, similar to conventional halogen bulbs, e.g., types GU10 or MR16 standard bulbs having outer rings on the reflector assembly, to permit the LED pixel assembly  10  to be directly substituted for the conventional bulbs. Alternately, the rear portion of the heat sink may be threaded (not shown) to fit into a threaded lighting fixture. The LED PCB assembly  16  rests atop individual flute portions  31  projecting radially inward from the outer radius of the heat sink  18 . Wire leads  36  have crimped contacts  21  that may be inserted into a contact carrier portion  13  and extend downward through channels  33  defined by the flute portions  31 . The number of contacts/wire leads  36  depends on the number of LEDs  28  that are mounted on the LED PCB assembly  16 . The LEDs may have two wire leads  36  for each of the LEDs  28 , or a plurality of LEDs may share a common ground or neutral wire. Various LED interconnections may be used, and the number of wire leads shown in the drawings is exemplary only, and not intended to limit the scope of the invention. The contact carrier portion  13  slides into the heat sink  18  against the LED PCB assembly  16  and latches into place under a flange portion  11 . The latches  15  secure the LED PCB assembly  16  into position, and force the electrical contacts portions  21  against the contact pads for positive electrical contact. The latches  15  also maintain thermal contact between the LED PCB assembly  16  and the heat sink  18 . In one embodiment, the latches  15  include step portions  19  to accept LED PCB assemblies  16  of multiple thicknesses. An optional lens portion  17  and lens connector  27  may be inserted in the LED connector assembly  10  to enhance the optical characteristics of the LED or LEDs  28  mounted thereon. Lip portions  29  are formed in the flange portion  11  and engage the lens portion  17  by spring force supplied by spring  38  (see, e.g.,  FIG. 4 ), to maintain the lens portion  17  in position. In one embodiment, flange portion  11  may include apertures  41  to provide airflow passages for improved heat dissipation. 
         [0029]    While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.