Abstract:
A heat dissipation assembly for dissipating heat from a heat-generating component includes a first heat sink mounted on the heat-generating component for dissipating heat therefrom, and a second heat sink movably mounted to the first heat sink, to be adjustable relative to the first heat sink. The second heat sink can be moved to a desired position to fit a need of heat dissipation.

Description:
BACKGROUND 
   1. Field of the Invention 
   The present invention relates to heat dissipation assemblies, and particularly to a heat dissipation assembly attached to a central processing unit (CPU). 
   2. Description of Related Art 
   Advances in microelectronics technology have led to computers processing signals and data at unprecedented high speeds. During operation large amounts of heat are produced by heat-generating components, especially by a CPU of a motherboard, in computers. Thus, heat dissipation assemblies are needed to cool CPUs. Generally, a heat dissipation assembly and a system fan are installed separately, however, this arrangement is not the most efficient to cool a CPU. 
   What is desired, therefore, is a heat dissipation assembly which provides high efficiency of heat dissipation for a CPU. 
   SUMMARY 
   An exemplary heat dissipation assembly for dissipating heat from a heat-generating component includes a first heat sink mounted on the heat-generating component for dissipating heat therefrom, and a second heat sink movably mounted to the first heat sink, to be adjustable relative to the first heat sink. 
   Other advantages and novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded, isometric view of a heat dissipation assembly in accordance with an embodiment of the present invention, the heat dissipation assembly includes a first heat sink and a second heat sink; 
       FIG. 2  is an inverted isometric view of the first heat sink of  FIG. 1 ; 
       FIG. 3  is an assembled view of  FIG. 1 ; 
       FIG. 4  is similar to  FIG. 3 , but showing the second heat sink in a different position; and 
       FIG. 5  is an assembled, isometric view of the heat dissipation assembly of  FIG. 3  and a host computer. 
   

   DETAILED DESCRIPTION 
   Referring to  FIG. 1 , a heat dissipation assembly in accordance with an embodiment of the present invention includes a fan  90 , a first heat sink  10 , a second heat sink  80 , a securing board  50 , a mounting board  70 , a clip  40 , and a fixing board  60 . 
   The fan  90  defines four pairs of through holes  96  in four corners thereof respectively. 
   Referring also to  FIG. 2 , the first heat sink  10  includes a base  20  for contacting a heat-generating component, such as a CPU of a motherboard  6  (see  FIG. 5 ) in the present embodiment, to transfer heat therefrom, and a first finned part including a plurality of fins  30  connected with the base  20 . The base  20  includes a rectangular supporting part  22 , and a circular shaped connecting part  24  extending down from a bottom face of the supporting part  22 . An annular groove  26  is defined in a circumference of the connecting part  24 . The fins  30  of the first finned part are parallel and extending perpendicularly from a top surface of the supporting part  22 . Two slots  34  are respectively defined in an upper portion of the first finned part at opposite ends of the fins  30 . Two C-shaped heat pipes  36  are inserted in the first heat sink  10 , with middle portions thereof exposed at a side of the heat sink  10 . An end of each heat pipe  36  passes through the upper portion of the first finned part and an opposite end of each pipe  36  passes through a junction of the first finned part and the base  20 , which enhances heat exchange between the first finned part and the base  20 . A through hole  38  is defined in the upper portion of the first heat sink  10  between the two heat pipes  36 , extending from one side of the heat sink  10  to the other. 
   Referring also to  FIG. 1 , the second heat sink  80  includes a heat-dissipating part and a heat-conducting part. The heat-dissipating part includes a U-shaped bracket  84  with two arms, and a second finned part including a plurality of parallel fins  86 , which is perpendicularly fixed to the two arms of the bracket  84 . A mounting hole  88  is defined in a lower portion of the bracket  84 . The heat-conducting part includes an L-shaped heat pipe  82 . One end of the heat pipe  82  passes through the fins  86  of the second finned part between the two arms of the bracket  84 , the other end of the heat pipe  82  is configured for engaging with the through hole  38  of the first heat sink  10 . 
   The securing board  50  includes a plurality of L-shaped hooks  58  extending down from opposite ends thereof. An opening (not labeled) is defined in a center of the securing board  50 , corresponding to the fan  90 . Four mounting holes  56  are respectively defined in four corners of the securing board  50 , corresponding to the through holes  96  of the fan  90 . A tongue  52  extends out from a side of the securing board  50 . Two holes  54  are defined in a distal end of the tongue  52 . 
   The mounting board  70  includes a rectangular horizontal piece  72 , and a rectangular vertical piece  74  extending form a side of the horizontal piece  72 . Two parallel sliding slots  73  are defined in the horizontal piece  72  corresponding to the two holes  54  of the securing board  50 , and perpendicular to the vertical piece  74 . An arc-shaped slot  75  is defined in the vertical piece  74 . 
   The clip  40  includes a ring-shaped main portion and four projecting portions  44  extending out from an outer side of the main portion. A mounting hole  42  is defined in a center of the main portion. A locking hole  46  is defined in each projecting portion  44 , with a fastening unit engaged therein. The fastening unit includes a screw  48  inserted in the locking hole  46 , a spring  49  fitting about the screw  48  and located upon the projecting portion  44 , and a clasp  47  clipped around the screw  48  and located under the projecting portion  44  for preventing the screw  48  from disengaging from the locking hole  46 . 
   The fixing board  60  is generally cross-shaped, with an opening defined in a center and four locking holes  62  respectively defined in four ends thereof. 
   Referring also to  FIGS. 3 and 4 , in assembly, four screws  98  are inserted through the corresponding through holes  96  of the fan  90  and screwed in the corresponding mounting holes  56  of the securing board  50 , in order to assemble the fan  90  and the securing board  50  together. The hooks  58  of the securing board  50  are correspondingly engaged in the slots  34  of the first finned part of the first heat sink  10  to combine the securing board  50  to the heat sink  10 . Two screws  76  are inserted through the corresponding sliding slots  73  of the mounting board  70  and then engaged in the corresponding holes  54  of the tongue  52  of the securing board  50 . Thus, the mounting board  70  is slidably mounted to the securing board  50 . Note here that the axis of the camber slot  75  of the moving board  70  should be the same as the axis of the through hole  38  of the first heat sink  10 . The end, away from the fins  86 , of the heat pipe  82  is slidably and rotatably inserted in the through hole  38  of the first heat sink  10 . A screw  89  is inserted through the mounting hole  88  of the second heat sink  80  and the slot  75 , to engage with a screw nut  87 . Thus, the second heat sink  80  is slidably mounted to the mounting board  70  and pivotable relative to the first heat sink  10  about the axis of the through hole  38  of the first heat sink  10 . A wall bounding the mounting hole  42  of the clip  40  is snappingly clipped in the groove  26  of the base  20  of the first heat sink  10 . The fixing board  60  is attached to a bottom of the motherboard  6 , and the connecting part  24  of the heat sink  10  is placed upon the CPU of the motherboard  6 . Four holes are defined through the motherboard  6  around the CPU. The screws  48  of the clip  40  are inserted through the corresponding holes of the motherboard  6  and engaged in the corresponding locking holes  62  of the fixing board  60 . Thus, the heat dissipation assembly is mounted to the motherboard  6 . 
   Referring also to  FIG. 5 , in use, the clip  40  and the fixing board  60  are mounted to the motherboard  6  that is mounted to a sidewall of a host computer  2  and sandwich the motherboard  6  therebetween, with the second finned part of the second heat sink  80  aligning with a system fan  4  that is mounted to a rear wall of the host computer  2 . When a distance between the system fan  4  and the second finned part of the second heat sink  80  needs to be adjusted, the two screws  76  are loosened, the mounting board  70  together with the second heat sink  80  is moved relative to the first heat sink  10 , the screws  76  slide in the corresponding sliding slots  73  of the mounting plate  70  and the heat pipe  82  of the second heat sink  80  slides in the through hole  38  of the first heat sink  30 , until the second heat sink  80  is located at a desired position. The screws  76  are tightly screwed into the corresponding holes  54  of the securing plate  50  to locate the mounting plate  70 . The second finned part of the second heat sink  80  is aligned with the system fan  4 , by loosening the screw nut  87  for the screw  89  and rotating the second heat sink  80 . The screw  89  slides in the slot  75  and the heat pipe  82  of the second heat sink  80  rotates in the through hole  38  of the first heat sink  30 , until the second finned part of the second heat sink  80  aligns with the system fan  4 , then the screw  89  is tightly engaged with the screw nut  87 . If needed, the screws  76  and the screw nut  87  can be loosened together, and the second heat sink  80  can be synchronously slid and rotated. 
   It is believed that the present embodiment and its advantage 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 exemplary embodiment of the invention.