Abstract:
An LED light fixture includes a post having a fixing bar at a top end thereof, a first lamp mounted on the fixing bar, and a second lamp rotatably mounted on the fixing bar. The first and second lamps are capable of rotating with respect to the fixing bar to change an angle between the first and second lamps, to thereby change an illumination area and intensity distribution of the LED light fixture. In one position, the second lamp overlaps the first lamp, and LED light sources in the first lamp are alternate with those of the second lamp.

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates generally to a light fixture, and more particularly to a light fixture using solid state light emitters, e.g., light emitting diodes (LEDs) as a light source, wherein the light fixture is versatile regarding the illuminating area and intensity. 
     2. Description of Related Art 
     LED lamp, a solid-state lighting, utilizes LEDs as a source of illumination, providing advantages such as resistance to shock and nearly limitless lifetime under specific conditions. Thus, LED lamps present a cost-effective yet high quality replacement for incandescent and fluorescent lamps. 
     A typical LED lamp is fixed onto a post and only illuminate at a given direction. In addition, the LED lamp provides a constant brightness at the given direction. This type of LED lamp fails to meet a requirement of an adjustable illumination direction or brightness. 
     What is need therefore is a light fixture which can overcome the above limitations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an isometric, assembled view of a light fixture in accordance with a first embodiment of the present disclosure, with a part thereof being cut away for clarity. 
         FIG. 2  is a cross-sectional view of the light fixture in  FIG. 1 , taken along line II-II thereof. 
         FIG. 3  is an isometric, assembled view of the light fixture in  FIG. 1 , shown in a different status. 
         FIG. 4  is an isometric, assembled view of a light fixture in accordance with a second embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     A light fixture of the present disclosure can be applied in roadways, plazas, parks or other places needing illumination. As shown in  FIG. 1 , the light fixture  10  in accordance with a first embodiment of the present disclosure comprises a post  11 , a first lamp  12  and a second lamp  13  both mounted on the post  11 . The post  11  has a columned fixing bar  111  at a top end thereof. The first and second lamps  12 ,  13  are rotatably mounted on the fixing bar  111 . 
     The first lamp  12  comprises a first frame  121 , a plurality of first light sources  122 , and a plurality of first heat sinks  123 . The first light sources  122  are spaced from each other and received in the first frame  121 . The first heat sinks  123  each are thermally connected to a corresponding first light source  122 . 
     The first frame  121  has a substantially rectangular shape and is preferably made of metallic material. The first frame  121  comprises a first sleeve  1211 , and a plurality of first supporting parts  1212  and first hollow parts  1213  extending horizontally from the first sleeve  1211  in a first predetermined direction. The first sleeve  1211  is rotatably mounted on the fixing bar  111  and the first lamp  12  is capable of rotating in the horizontal plane with respect to a central axis O 1 O 2  of the fixing bar  111 . There are four first supporting parts  1212  and four first hollow parts  1213  in this embodiment. It is noted that, the numbers of the first supporting parts  1212  and the first hollow parts  1213  can be changed in other embodiments, such as only one first supporting part  1212  and one first hollow part  1213  in an alternative embodiment. The first supporting parts  1212  and the first hollow parts  1213  are alternately arranged along an elongated direction of the first frame  121 , i.e., a radial direction of the light fixture. That is, each one of the first hollow parts  1213  is located between two adjacent first supporting parts  1212 , excepting the one connecting to the first sleeve  1211 . It is to be understood that, in alternative embodiments, an additional first supporting part  1212  can be provided to connect with the first sleeve  1211 . In this way, every one of the first hollow parts  1213  is located between two adjacent first supporting parts  1212 . The first supporting parts  1212  and the first hollow parts  1213  each have a shape of an arc in a top plan view thereof, and the first supporting parts  1212  are concentric with the first hollow parts  1213 , each with a center thereof locating on the axis O 1 O 2  of the fixing bar  111 . The first hollow parts  1213  each define a window  1214  therein. The first supporting parts  1212  each form a sidewall which defines a first receiving room  1212 A for receiving a corresponding first light source  122  and a corresponding first heat sink  123  therein. 
     The first light sources  122  each comprise a first base  1221  and a plurality of first light emitting elements  1222  mounted on a bottom of the first base  1221 . In this embodiment, the first light emitting elements  1222  are LEDs. The first light emitting elements  1222  face downwardly to allow light generated therefrom to radiate downwards through the first receiving room  1212 A to lighten an object needing illumination. The first heat sink  123  is disposed on the first base  1221  of the first light source  122  to dissipate heat generated by the first light source  122 . 
     The second lamp  13  comprises a second frame  131 , a plurality of second light sources  132  spaced from each other and received in the second frame  131 , and a plurality of second heat sinks  133  each thermally connected to a corresponding second light source  132 . 
     The second frame  131  has a substantially rectangular shape and is preferably made of metallic material. The second frame  131  comprises a second sleeve  1311 , and a plurality of second supporting parts  1312  and second hollow parts  1313  extending horizontally from the second sleeve  1311  in a second predetermined direction which is different from the first predetermined direction. The second sleeve  1311  is rotatably mounted on the fixing bar  111  and located on the first sleeve  1211  of the first lamp  12 . The second lamp  13  is capable of rotating in the horizontal plane with respect to the center axis O 1 O 2  of the fixing bar  111  to change the angle between the first and second lamps  12 ,  13 . The second supporting parts  1312  and the second hollow parts  1313  are alternately arranged. One of the second supporting parts  1312  connects to the second sleeve  1311  in this embodiment. It is to be understood that, in alternative embodiments, an additional second hollow part  1313  can be provided to connect with the second sleeve  1311 . Further, there are four second supporting parts  1312  and four second hollow parts  1313  in this embodiment. Of course the numbers of the second supporting parts  1312  and second hollow parts  1313  can be changed in other embodiments, such as only one of the second supporting parts  1312  and one of the second hollow parts  1313  in an alternative embodiment. The second supporting parts  1312  and the second hollow parts  1313  each have a shape of an arc in a top plan view thereof, and the second supporting parts  1312  are concentric with the second hollow parts  1313 , each with a center thereof locating on the axis O 1 O 2  of the fixing bar  111 . The second hollow parts  1313  each define a window  1314  therein. The second supporting parts  1312  each form a sidewall, which defines a second receiving room  1312 A for receiving a corresponding second light source  132  and a corresponding second heat sink  133  therein. 
     Referring to  FIG. 2 , the second light sources  132  each comprise a second base  1321  and a plurality of second light emitting elements  1322  mounted on a bottom of the second base  1321 . In this embodiment, the second light emitting elements  1322  are LEDs. The second light emitting elements  1322  face to an opening of the second receiving room  1312 A to allow light generated therefrom projecting downwardly and out of the second receiving room  1312 A. The second heat sink  133  is disposed on the second base  1321  of the second light source  132  to dissipate heat generated by the second light source  132 . 
     The first and second lamps  12 ,  13  are capable of rotating with respect to the fixing bar  111 , whereby the first and second lamps  12 ,  13  can be oriented toward different directions or a same direction so that the light fixture  10  can be used to meet different requirements. As shown in  FIG. 3 , the second lamp  13  is rotated to be oriented toward the first predetermined direction and fitly engaged with the first lamp  12  to increase a brightness in that direction. Specifically, the second supporting parts  1312  of the second lamp  13  are respectively located on the first hollow parts  1213  of the first lamp  12 , and the second hollow parts  1313  of the second lamp  13  are respectively located on the first supporting parts  1212  of the first lamp  12 . Since the first and second supporting (hollow) parts  1212 ,  1312  ( 1213 ,  1313 ) of the first and second lamps  12 ,  13  are configured to be arc-shaped and have similar sizes, each second supporting part  1312  of the second lamp  13  can be fitly engaged between two corresponding adjacent first supporting parts  1212  of the first lamp  12 . 
     A circumferential length of the supporting (hollow) parts of the lamps can be changed as desired.  FIG. 4  shows a light fixture  20  in accordance with a second embodiment of the present disclosure. Similar to the light fixture  10  of the first embodiment, the light fixture  20  also comprises a post  21 , a first lamp  22  and a second lamp  23  both rotatably mounted on the post  21 . The difference between the light fixtures  10 ,  20  is that, first and second frames  221 ,  231  of the first and second lamps  22 ,  23  of the light fixture  20  each have a substantially semicircular shape. Specifically, the first frame  221  of the first lamp  22  comprises four semicircular first supporting parts  2212  and four semicircular first hollow parts  2213 . The first supporting parts  2212  and the first hollow parts  2213  are alternately arranged. The second frame  231  of the second lamp  23  comprises four semicircular second supporting parts  2312  and four semicircular second hollow parts  2313 . The second supporting parts  2312  and the second hollow parts  2313  are alternately arranged. 
     When the first and second lamps  22 ,  23  are disengaged with each other, as shown in  FIG. 4 , the first and second lamps  22 ,  23  form a substantially round lamp with light sources received in the first and second supporting parts  2212 ,  2312 . Since the first and second lamps  22 ,  23  are capable of rotating with respect to the post  21 , the first lamp  22  can be fitly engaged with the second lamp  23 , with each second supporting part  2312  of the second lamp  23  fitly received between two corresponding adjacent first supporting parts  2212  of the first lamp  22 . 
     It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the disclosure.