Patent Publication Number: US-7712923-B2

Title: LED lamp assembly

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to an LED lamp assembly, and more particularly to an LED lamp assembly having a gasbag to adjust pressure in an airproof chamber of the LED lamp assembly via expanding and shrinking of the gasbag. 
   2. Description of Related Art 
   A conventional LED lamp comprises a heat sink, a plurality of LED modules having LEDs attached to an outer surface of the heat sink and an envelope engaging with the outer surface of the heat sink. The envelope and the heat sink forms a chamber to receive the LED modules therein. When the LED lamp works, heat is generated by the LED modules; air in chamber of the LED lamp is heated to expand. Therefore a pressure in the chamber of the LED lamp is higher than that outside the chamber. When the LED lamp is cooled, an airflow of the ambient air with impurity is drawn into the chamber of the LED lamp. Therefore, the LED modules and other components inside the LED lamp are contaminated by the impurity. 
   What is needed, therefore, is an LED lamp assembly having a gasbag to adjust pressure in an airproof chamber of the LED lamp assembly. 
   SUMMARY OF THE INVENTION 
   An LED lamp assembly includes an LED lamp and a driving circuit module mounted on the LED lamp. The LED lamp includes an airproof chamber. A plurality of LED modules is received in the airproof chamber. A gasbag is located at the driving circuit module and communicates with the airproof chamber of the LED lamp. The gasbag can adjust a pressure of the airproof chamber. 
   Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which: 

   
     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 assembled, isometric view of an LED lamp assembly in accordance with a preferred embodiment of the present invention. 
       FIG. 2  is an exploded view of  FIG. 1 . 
       FIG. 3  is an inverted view of  FIG. 2 . 
       FIG. 4  is an assembled, isometric view of a driving circuit module of  FIG. 1 . 
       FIG. 5  is an exploded view of  FIG. 4 . 
       FIG. 6  is an exploded view of  FIG. 4 , but shown from another aspect. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIG. 1 , an LED lamp assembly comprises an LED lamp  10  and a driving circuit module  30  mounted on a side of the LED lamp  10 . 
   Referring to  FIGS. 2-3 , the LED lamp  10  comprises a heat sink  11 , a plurality of LED modules  12  mounted on the heat sink  11 , two reflectors  14  mounted on the heat sink  11  and over the LED modules  12 , a frame  16  mounted on the heat sink  11 , a transparent cover  17  inserted in the frame  16 , and a pressing member  18  pressing the cover  17 . The heat sink  11 , the frame  16 , the cover  17 , and the pressing member  18  form an airproof chamber. 
   The heat sink  11  comprises an elongated base  111  and a plurality of fins  113  extending downwardly from a bottom surface of the base  111 . The base  111  defines a through hole  1112  in a center portion thereof. A receiving trap  115  is defined in the fins  113  and communicates with the through hole  1112  of the base  111 . The LED modules  12  thermally contact a top surface of the base  111 . 
   Each LED module  12  comprises an elongated printed circuit board  123  and a plurality of spaced LEDs  121  evenly mounted on a side of the printed circuit board  123 . The LEDs  121  of each LED module  12  are arranged along a longitudinal direction of the printed circuit board  123 . Each LED module  12  is mounted in a thermally conductive relationship with the top surface of the heat sink  11  and electronically connects with the driving circuit module  30 . 
   Each reflector  14  comprises a plurality of spaced, vertical connecting plates  141 , a U-shaped engaging portion  143  around the connecting plates  141 , a plurality of reflecting plates  145  sandwiched between the connecting plates  141  to reflect light emitted from the LED modules  12 . The engaging portion  143  is mounted on the base  111  of the heat sink  11 . Each of the reflecting plates  141  covers a corresponding LED module  12 . 
   The frame  16  has a rectangular configuration and defines a rectangular opening  161  in a center portion thereof. The frame  16  encloses the LED modules  12  therein. The cover  17  is rectangular and mounted on the frame  16 . The pressing member  18  is annular and engages with the frame  16  to sandwich the cover  17  therebetween. A ring-shaped gasket  13  is sandwiched between the base  111  of the heat sink  11  and the frame  16 . Another ring-shaped gasket  15  is sandwiched between the frame  16  and the pressing member  18 . These gaskets  13 ,  15  are used to enhance hermeticity of the LED lamp  10 . 
   Referring to  FIGS. 4-6 , the driving circuit module  30  comprises a driving portion  31  and a connecting portion  33  extending towards the heat sink  11 . 
   The driving portion  31  has a cuboid configuration. The driving portion  31  comprises an annular main body  311  and a rectangular engaging plate  313  fittingly received in the main body  311 . The main body  311  is divided into two portions by the engaging plate  313 . An elongated first baffling plate  315  and a second baffling plate  317  close opposite ends of the main body  311 . The second baffling plate  317 , the main body  311  and the engaging plate  313  defines a first chamber  318 . The first baffling plate  315 , the main body  311  and the engaging plate  313  defines a second chamber  319 . The first chamber  318  is airproof and a driving module  34  is received therein to electronically connect with the LED modules  12 . A plurality of slots  314  is defined in a side of the main body  311  corresponding to the second chamber  319  to make the second chamber  319  communicate with the ambient. A tube  35  extends through the engaging plate  313 . The tube  35  is fixed to the engaging plate  313  by a nut  36 . A gasbag  37  is located at the second chamber  319  and connects with the tube  35 . 
   The connecting portion  33  is located at a center portion of a side of the driving portion  31 . The connecting portion  33  is cuboid. A through hole  331  is defined in a center portion of the connecting portion  33  to make the connecting portion  33  communicate with the first chamber  318  of the driving portion  31 . The connecting portion  33  is received in the receiving trap  115  of the heat sink  11 . The through hole  331  of the connecting portion  33  corresponds to the through hole  1112  of the base  111  of the heat sink  11 . A plurality of screws  40  extends through the base  111  of the heat sink  11  and engages with the connecting portion  33  to assemble the driving circuit module  30  on the heat sink  11 . 
   When the LED modules  12  are activated, heat generated by the LEDs  121  is absorbed by the heat sink  11 . The pressure of air in the airproof chamber defined by the heat sink  11 , the frame  16 , the cover  17 , and the pressing member  18  is raised; thus, the air of the airproof chamber enters into the gasbag  37  via the tube  35  to adjust the pressure in the airproof chamber. When the LED lamp  10  is cooled, the pressure of the airproof chamber is reduced, and the air of the gasbag  37  is drawn into the airproof chamber of the LED lamp  10  through the tube  35 . 
   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 invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.