Abstract:
A heat dissipation device for at least a heat-generating electronic component includes a heat sink, a fan for providing an airflow through the heat sink and a fan holder coupling the fan to the heat sink. The heat sink has a first locking part and a second locking part opposite to the first locking part. The fan holder has a first engaging part engaging with the first locking part at one side of the heat sink and a second engaging part engaging with the second locking part of the heat sink at an opposite side thereof. The first engaging part has a horizontally extending fixing arm and a barb extending downwardly from the fixing arm and hooking with a top side of the heat sink.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to a heat dissipation device, and more particularly to a heat dissipation device having a heat sink and a fan holder for facilitating mounting of a fan on the heat sink. 
   2. Description of Related Art 
   Generally, in order to ensure the normal running of an electronic device, a heat dissipation device is used to dissipate heat generated by the electronic device. A conventional heat dissipation device includes a heat sink and a fan attached on the heat sink to improve a heat-dissipation capacity of the heat sink. 
   When installing the fan to the heat sink, it is generally to fix the fan to a side of the heat sink via a fan holder with screws. Although using the screws can achieve the fastening objective, it requires a lot of manpower and material resource. Furthermore, it is necessary to remove the fan first by unscrewing the screws when disassembling and maintaining the heat dissipation device. Such unscrewing operation is tiresome for a user. In addition, it is also possible that the unscrewed screws may fall into a computer in which the heat dissipation device is mounted to cause damages to components of the computer. 
   What is need therefore is a heat dissipation device having a design which makes assembling and disassembling of a fan to/from a heat sink of the heat dissipation device be convenient and easy. 
   SUMMARY OF THE INVENTION 
   The present invention relates to a heat dissipation device for dissipating heat generated by a heat-generating electronic component. The heat dissipation device includes a heat sink, a fan for providing airflow through the heat sink and a fan holder coupling the fan to the heat sink. The heat sink has a first locking part and a second locking part opposite to the first locking part of the heat sink. The fan holder has a first engaging part engaging with the first locking part at one side of the heat sink and a second engaging part engaging with the second locking part at an opposite side of the heat sink. 
   Other advantages and novel features of the present invention will become more apparent from the following detailed description of preferred embodiment when taken in conjunction with the accompanying drawings, in which: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Many aspects of the present device 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 device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
       FIG. 1  is an assembled view of a heat dissipation device in accordance with a preferred embodiment of the present invention; 
       FIG. 2  is an exploded, isometric view of  FIG. 1 ; 
       FIG. 3  is an exploded, isometric view of a heat sink of the heat dissipation device of  FIG. 2 ; 
       FIG. 4  is an inverted view of a fan holder of the heat dissipation device of  FIG. 2 ; and 
       FIG. 5  is an assembled view of the fan holder with a fan of the heat dissipation device of  FIG. 2 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 1-3 , a heat dissipation device in accordance with a preferred embodiment of the present invention is shown. The heat dissipation device is used to be mounted to two heat-generating electronic elements  70 , to dissipate heat therefrom. The heat dissipation device comprises a heat sink, a fan holder  50  secured at a front side of the heat sink and a fan  60  attached to the fan holder  50 . 
   The heat sink comprises a base  10 , a fin set  30  located on the base  10 , a heat pipe assembly  20  thermally connecting the base  10  and the fin set  30  and a fin cover  40  covering top and two opposite lateral sides of the fin set  30 . 
   The base  10  comprises a supporting frame  13  and two plates  11  attached to a bottom of the supporting frame  13  for contacting with the two corresponding heat-generating electronic elements  70 . Each of the plates  11  is made of good conductive material such as copper, and is rectangular in shape and defines three parallel receiving, grooves  110  in a top surface thereof. The supporting frame  13  comprises two spaced and parallel shoulders  132  and two spaced and parallel bridges  134  connecting the two shoulders l 32  together. The bridges  134  are perpendicular to the shoulders  132 . The supporting frame  13  is provided with a first locking part for engaging with the fan holder  50 . In this embodiment, the first locking part is two fixing slots  1320  parallel to the shoulders  132 . The two fixing slots  1320  are defined in two joints of the two bridges  134  with one of the shoulders  132  for engaging with the fan holder  50 . A plurality of countersinks  1322  are defined in the shoulders  132 , adjacent to two remote edges thereof, for receiving fixtures  102  to attach the heat sink onto the heat-generating electronic elements  70 . The two shoulders  132  are respecetively provided with two step portions  1324  that face to each other, for receiving the plates  11  under the frame  13 . Each of the shoulder  132  defines two mounting orifices  1326  in two opposite lateral ends thereof. for engaging with screws  100  to secure the fin cover  40  to the base  10 , The two bridges  134  define a rectangular opening  130  therebetween. Two cutoffs (not labeled) are defined beside the bridges  134 , respectively, and between the shoulders  132 . Each of the bridges  134  defines three parallel receiving grooves  1340  in a bottom surface thereof corresponding to the receiving grooves  110  of the plates  11 . 
   The heat pipe assembly  20  includes two groups of heat pipe, each having three heat pipes  21 . Each of the heat pipes  21  is U-shaped in profile and comprises an evaporating section  217 , two parallel condensing sections  214  perpendicular to the evaporating section  217  and two curved connecting sections (not labeled) extending from two opposite ends of the evaporating section  217  and connecting the evaporating section  217  with corresponding condensing sections  214 . 
   The fin set  30  comprises a plurality of fins  32  and defines four spaced and parallel rows of receiving holes  34  for receiving the condensing sections  214  of the heat pipes  21 . Two rows of the receiving holes  34  are defined in a middle portion of the fin set  30 , and the other two rows of me receiving holes  34  are defined in two lateral portions of the fin set  30 , respectively. Each row of the receiving holes  34  includes three receiving holes  34  vertically extending through the fin set  30 . Each tin  32  is made of a rectangular metallic plate. 
   The fin cover  40  is integrally made of a piece of metal sheet and comprises a rectangular top panel  42  and two sidewalls  44  extending perpendicularly and downwardly from two lateral opposite edges of the top panel  42 . The top panel  42  is provided with a second locking part at a middle portion thereof, for securing the fan holder  50  to the fin cover  40 . In this embodiment, the second locking part is a connecting sheet  422  recessing from a top surface of the top panel  42 . The connecting sheet  422  defines a locking orifice  4220  therein, for engaging with the fan holder  50 . Due to the recessing of the connecting sheet  422 , the top panel  42  forms a concave portion in a middle thereof. The connecting sheet  422  has a width less than that of other portion of the top panel  42 . The two sidewalls  44  are constructed to be disposed snugly on the two opposite lateral sides of the fin set  30 . The two sidewalls  44  each have a width increasing gradually in a same direction from a top to a bottom thereof. A bottom end of each of the sidewalls  44  is bent inwardly and perpendicularly, then further downwardly and perpendicularly to form a mounting leg  442 . Each of the mounting legs  442  defines two fixing orifices  4420  adjacent to two opposite ends thereof, for allowing the screws  100  to extend therethrough to screw into the mounting orifices  1326  of the base  10 . 
   Particularly referring to  FIG. 2 , in assembly of the heat sink, the evaporating sections  217  of two groups of the heat pipes  21  are sandwiched between the two respective plates  11  and the two corresponding bridges  134  of the supporting frame  13  and received respectively in channels formed cooperatively by the receiving grooves  110 ,  1340  of the two plates  11  and the bridges  134  of the supporting frame  13 ; the condensing sections  214  of two groups of the heat pipes  21  are engagingly received in the receiving holes  34  of the fin set  30 , respectively; thus, the base  10  and fin set  30  are thermally connected together by the heat pipes  21 . The fin cover  40  covers on the fin set  30  and is secured to the base  10  by the screws  100  extending through the corresponding fixing orifices  4420  of the mounting legs  442  of the sidewalls  44  to screw into the mounting orifices  1326  of the base  10 . 
   It can be easily understood in some embodiment, the fin cover  40  can be omitted. Correspondingly, a top fin  32  of the fin set  30  defines a locking orifice replacing the locking orifice  4220  of the fin cover  40  to engage with the fan holder  50 . 
   As shown in  FIG. 4 , the fan holder  50  is formed by molded plastic material and substantially ring-shaped. The fan holder  50  has a ring body  51  with a through hole  52  therein for allowing air flow generated by the fan  60  to pass through the fan holder  50 . The ring body  51  defines a plurality of engaging orifices  510  therein for engaging with corresponding fixtures  200  to attach the fan  60  onto the fan holder  50 . The fan holder  50  is provided with a first engaging part at an upper edge of the ring body  51  and a second engaging part at a lower edge of the ring body  51  opposite to the upper edge. In this embodiment, the first engaging part is a fixing arm  54  that extends perpendicularly and rearwards from a top of the ring body  51 . The fixing arm  54  has a barb  540  extending downwardly form a middle of a bottom surface thereof and matching with the locking orifice  4220  of the fin cover  40 . The second engaging part is two inhibiting tabs  56  protruding downwardly from a bottom of the ring body  51  for engaging into the fixing slots  1320  of the base  10 . 
   The fan  60  has a frame (not labeled) with a shape and size corresponding to that of the fan holder  50 . The frame defines a plurality of through orifices  62  ( FIG. 2 ) corresponding to the engaging orifices  510  of the fan holder  50 , for receiving the fixtures  200 . 
   In assembly of the heat dissipation device, the fan holder  50  and the fan  60  are assembled into a fan assembly by the fixtures  200  extending through the through orifices  62  of the fan  60  to engage into the engaging orifices  510  of the fan holder  50 . The fixing arm  54  of the fan holder  50  of the fan assembly is disposed in the concave portion of the fin cover  40  and supported by the connecting sheet  422  of the fin cover  40  with the barb  540  of the fixing arm  54  aligned with the locking orifice  4220  of the fin cover  40 . The fan holder  50  of the fan assembly is then pressed downwardly to force the barb  540  of the fixing arm  54  to be interferentially fitted into the locking orifice  4220  of the fin cover  40 . As soon as the barb  540  of the fixing arm  54  fits in the locking orifice  4220  of the fin cover  40 , the barb  540  hooks with the connecting sheet  422  of the fin cover  40 . When the barb  540  is engaged into the locking orifice  4220  of the fin cover  40 , the two inhibiting tabs  56  at the bottom of the fan holder  50  of the fan assembly are forced to be engagingly inserted into the two corresponding fixing slots  1320  of the frame  13  of the base  10 . The fan  60  combined with the fan holder  50  is thus mounted to the heat sink securely and easily. To detach the fan assembly from the heat sink, a user only needs to pull the fixing arm  54  upwardly by hand to release the hooked connection between the barb  540  and the connecting sheet  422 ; then the fan assembly can be pulled away from the heat sink easily. 
   According to aforementioned description, assembling and disassembling of the fan assembly consisting of the fan  60  and the fan holder  50  to/from the heat sink can be easily and simply completed by the user using his (her) hands, without requiring any special tool to rotate a plurality of screws. 
   It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.