Abstract:
The inventive directionally-adjustable LED spotlight is comprised of a fixed heat sink and an LED-array-bearing structure. The LED-array-bearing structure is adjustably attached in a heat transfer relationship to the fixed heat sink.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention is related generally to light fixtures and, more particularly, to LED (Light Emitting Diodes) spotlights that include the capability of being directionally adjusted. 
       BACKGROUND OF THE INVENTION 
       [0002]    In LED light fixtures, heat management is a highly important criteria since LEDs produce heat that is directed primarily in the direction opposite from the light emanation. Therefore, it is desirable to have a heat sink or other heat dissipation apparatus located behind the LED array. This need for a heat sink has led to the configuration of LED fixtures to include a heat sink in a fixed relationship to the LED array. 
         [0003]    Furthermore, this fixed relationship between the heat sink and the LED array has caused difficulty in designing an adjustable spotlight type fixture while utilizing LEDs, because the combination of the heat sink with the LED array, leads to an elongated arrangement that is difficult to reposition and leads to tall fixtures when incorporating both the heat sink and the array into the fixture. In light fixtures intended for positioning at considerable height, this presents particularly great difficulties for effectively positioning and locking the spotlight into place. 
         [0004]    While a vast array of LED light fixtures have been developed, a need exists for an improved LED spotlight fixture adapted for easy repositioning yet still having effective heat dissipation characteristics 
       OBJECTS OF THE INVENTION 
       [0005]    It is an object of the invention to provide an LED spotlight fixture overcoming some of the problems and shortcomings of the prior art, including those referred to above. 
         [0006]    Another object of the invention is to provide an LED spotlight fixture adapted for easy repositioning while still maintaining heat dissipation so that the fixture operates safely. 
         [0007]    How these and other objects are accomplished will become apparent from the following descriptions and the drawings. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention provides an LED spotlight fixture designed for easy repositioning of the light while maintaining proper heat dissipation. This invention, which will be described in detail below, is an improvement in LED light design where the LED array and the heat sink were in a fixed relationship with each other. 
         [0009]    The inventive directionally-adjustable LED spotlight is comprised of a fixed heat sink and an LED-array-bearing structure. The LED-array-bearing structure is adjustably attached in a heat transfer relationship to the fixed heat sink. 
         [0010]    In a preferred embodiment of the directionally-adjustable LED spotlight, the fixed heat sink is of a socket-shaped design and the LED-array-bearing structure is of a ball-shaped design corresponding to the socket-shape of the heat sink. The ball and socket design allows for maximum contact between the heat sink and the LED-array-bearing structure thus facilitating the maximum transfer of heat to the heat sink. 
         [0011]    In a further preferred embodiment of the current invention, the directionally-adjustable LED spotlight further includes a retention assembly in the form of a collar that is releasably secured around an upper edge of the fixed heat sink. The retention assembly secures the LED-array-bearing structure in firm contact with the heat sink and can be loosened to move the LED-array-bearing structure to shift the focus of the spotlight. 
         [0012]    In another preferred embodiment the LED-array-bearing structure includes a ball portion and an LED array attached to the ball portion and including a plurality of LEDs. 
         [0013]    In yet another preferred embodiment of the current invention, the heat sink and the ball portion of the LED-array-bearing structure are made from a heat-conducting material such as metal and the heat sink includes a plurality of fins extending outwardly from the ball-shaped LED-array-bearing structure. This construction from a heat conducting material facilitates the transfer of heat from the LEDs to the heat sink and the fins provide increased surface area from which the heat can dissipate. 
         [0014]    This invention is based in part on the discovery that sufficient heat transfer can occur by contacting partial spherical surfaces together to enable the LED array to safely function. This allows moving the heat sink further from the LED array and therefore allows for the introduction of an adjustable attachment between the LED array and the heat sink. As long a heat transfer relationship (a connection that allows efficient transfer of heat from one portion to the other) exits between the LED array and the heat sink, the addition of the adjustable attachment does not impede safe operation of the LEDs. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a perspective view of a preferred embodiment of a directionally-adjustable LED spotlight of the present invention oriented if the embodiment were mounted in a ceiling. 
           [0016]      FIG. 2  is a side view of the fixed heat sink of the embodiment of  FIG. 1 . 
           [0017]      FIG. 3   a  is a top view of the fixed heat sink of  FIG. 2 . 
           [0018]      FIG. 3   b  is a side view of the ball portion of the LED-array bearing structure of  FIG. 1 . 
           [0019]      FIG. 4   a  is a top view of the ball portion of the LED-array-bearing structure of  FIG. 3   b.    
           [0020]      FIG. 4   b  is a top view of the LED array of the LED-array-bearing structure of the embodiment of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]      FIG. 1  illustrates a preferred embodiment of a directionally-adjustable LED spotlight  10  of the current invention. The LED spotlight  10  includes a fixed heat sink  20  and an LED-array-bearing structure  30 . As seen in  FIG. 2 , the heat sink  20  is in a socket shape shown in the socket portion  22  and further includes a plurality of fins  24  that extend outwardly from an outer surface  26  of the heat sink  20 . 
         [0022]    Referring again to  FIG. 1 , the LED-array-bearing structure  30  includes a ball portion  32  and an LED array  34 . As can be seen in  FIGS. 3   a  and  3   b , the ball portion  32  is sized to fit inside the socket portion  22  of the heat sink  20 . Furthermore, the ball portion  32  is made of metal and is hollow. The ball and socket design of the heat sink  20  and the LED-array-bearing structure  30  allow for the entirety of the socket portion  22  of the heat sink  20  to be in contact with the ball portion  32  of the LED-array-bearing structure  30 . This contact ensures a heat transfer relationship between the two parts. 
         [0023]    As shown in  FIG. 4   a  the ball portion  32  is not completely spherical, rather the ball portion  32  includes platform portion  36  that defines the top of the ball portion  32 .  FIG. 4   b  shows the LED array  34  that includes a first side  38  having a plurality of LEDs  40  and second side (not shown). As seen in  FIGS. 4   a  and  4   b  the platform portion  36  is sized to receive the LED array  34  wherein the second side of the LED  34  array will come in contact with the platform portion  36 . This sizing arrangement allows for efficient heat transfer from the LED array  34  to the ball portion  32  whereby heat can be transferred to the heat sink  20  and the fins  24 . 
         [0024]    Referring again to  FIG. 1 , the LED spotlight  10  further includes a collar  12  for securing the LED-array-bearing structure  30  in place. Once the LED-array-bearing structure  30  has been positioned in the heat sink  20  the collar  12  fits over the LED-array-bearing structure  30  and comes in contact with an upper edge  28  of the heat sink  20 . The collar  12  is then secured using screws or other means and the LED-array-bearing structure  30  is then secured in place. In other embodiments, not shown the collar could be divided into sections rather than one piece. To readjust the LED-array-bearing structure  30  the collar  12  must simply be loosed and the LED-array-bearing structure  30  can be rotated to a different angle. 
         [0025]    While the principles of the invention have been shown and described in connection with specific embodiments, it is to be understood that such embodiments are by way of example and are not limiting.