Abstract:
An adjusting air duct adopts a novel design so that it is movable according to the location of the heat generating source in a computer host to be aligned with air vents of the side board of the computer host. Therefore external cooling air may be sucked in through fans and channeled to the heat generating source through the air duct to achieve optimal heat dissipation effect.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to an adjusting air duct and particularly to an air duct movable to match air vents of the side board of a computer host according to the location of the heat generating source of the computer host.  
       BACKGROUND OF THE INVENTION  
       [0002]     The heat generating source of a general computer host such as CPU generates a lot heat during operation. Hence suitable heat dissipation measures must be taken to enable the CPU to function normally without being overheated and damaged.  
         [0003]     The conventional radiation device for CPU has a plurality of upright radiation fins mounted onto the CPU and a fan located above the radiation fins. The radiation fins absorb heat from the CPU, and the fan dispels the heat from the radiation fins so that the CPU can maintain a suitable operation temperature.  
         [0004]     Due to the processing speed of CPU increases continuously, heat generated by the CPU also increases. Heat dissipation efficiency of the radiation device for the CPU also has to increase to prevent the CPU from overheated or damaged.  
         [0005]     The conventional radiation fan is an axial fan which draws air axially and discharges the air at another side. Airflow is directed vertically and results in air turbulence in the computer case. The irregular airflow in the computer case affects air exchange between the air inside and outside the computer case, and reduces the performance of the total heat dissipation system. To remedy this problem, there is a design to install a hood above the CPU. The hood has an outlet to couple with an air duct which is connected to an air vent of the computer case. A fan is installed on a lower side of the hood or abutting the air vent of the computer case to generate forced air exchange between the interior and the exterior of the computer case. The fan can generate a steady airflow in a closed environment, and the airflow speed can increase. Thus an improved heat dissipation effect may be achieved. However, the air duct usually is flexible, and tends to bend and twist in the computer case. As a result, airflow generated by the fan will hit and bump the air duct and form an irregular flow. This causes undesirable airflow in the case.  
         [0006]     To overcome the aforesaid air duct problem, there is a technique disclosed in R.O.C. patent publication No. 481286 entitled “Air duct coupling apparatus”. It has an air duct consisting of two opposing tubes that are coupled together. The air duct is anchored on the case through a pair of juxtaposed latch hooks and an elastic latch blade. R.O.C. patent publication No. 537428 entitled “Computer air channeling apparatus” discloses an air duct consisting of a first tube and a second tube that are integrally formed and connected in a normal manner. The first tube has one end anchored on the heat generating source, and the second tube has one end anchored on the air vent of the computer case through a fastening element. R.O.C. patent publication No. 562393 entitled “Screwless air duct anchoring apparatus” discloses an air duct which has one side coupled with an elbow tube for housing a fan. The air duct is straddled the air discharge vent of the computer host through a plurality of hook pawls and latch hooks. All of aforesaid references have an air duct to bridge the heat generating source and the air vent of the computer case to form a regular airflow in the air duct so that air exchange speed between the interior and the exterior of the computer case may increase to improve heat dissipation.  
         [0007]     However, the installation location of the heat generating source (such as CPU) on the main board varies among different vendors. One type of air duct cannot fit all of them equally well. In some occasions, the air duct cannot be aligned correctly with the air vent and results in not desirable heat dissipation effect. Moreover, different vendors and brands have different element arrangement in the computer case. The same air duct structure could be not fitting in some interior space or cause conflict with the element installation locations.  
       SUMMARY OF THE INVENTION  
       [0008]     The primary object of the present invention is to solve the aforesaid disadvantages. The present invention provides an adjusting air duct that is adjustable according to different installation locations of the heat generating source on the main board so that the air duct may be always aligned with the air vent of the computer case to avoid the problem of failing to suck in the external cooling air caused by wrong alignment of the air duct and the air vent resulting from change of heat generating source location.  
         [0009]     To achieve the foregoing object, the adjusting air duct according to the invention includes an air duct assembly which consists of a first duct and a second duct that are pivotally coupled through a first coupling means to adjust their relative positions, and an adjusting member to pivotally couple with the second duct through a second coupling means to adjust their relative positions so that when the installation location of the heat generating source in the computer case is changed the elements set forth above may be adjusted through the first and the second coupling means to align the ventilation opening of the air duct with the air vent of the computer case to achieve optimal heat dissipation effect.  
         [0010]     The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a schematic view of the present invention in use.  
         [0012]      FIG. 2  is an exploded view of the present invention.  
         [0013]      FIGS. 3A, 3B  and  3 C are schematic views of the adjusting member and the second duct in adjustment conditions.  
         [0014]      FIGS. 4A and 4B  are schematic views of the first duct and the second duct in adjustment conditions.  
         [0015]      FIG. 5  is a schematic view of the airflow according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0016]     Please referring to  FIGS. 1 and 2 , the adjusting air duct according to the present invention includes an air duct assembly  10  located between radiation fins  30  mounted onto a heat generating source (such as a CPU  50 , referring to  FIG. 4A ), a first fan  40  and air vents  23  of a side board  22  of a computer case  20 . The air duct assembly  10  has a ventilation opening  122  on one end to hold a second fan  40 ′. There is an adjusting member  13  located above the ventilation opening. The adjusting member  13  has an elongate fastening slot  134  and may be slid on a sliding track  21  and fastened thereon through a fastening element  15  to a fastening hole  211  formed on the sliding track  21 . The first fan  40  and second fan  40 ′ can suck external cooling air through the air vents  23  and the air duct assembly  10  to blow the radiation fins  30  to reduce the temperature of the CPU  50  (referring to  FIG. 5 ).  
         [0017]     Referring to  FIG. 2 , the air duct assembly  10  includes a first duct  11  and a second duct  12 . The first duct  11  is located on the radiation fins  30  and the first fan  40 . The second duct  12  is pivotally coupled with the first duct  11  through a first coupling means which adjusts the relative position of the first duct  11  and the second duct  12 .  
         [0018]     The first coupling means includes an annular member  111  formed on the first duct  11  to cover the radiation fins  30  and a tube  112  extending from the center of the annular member  111 . The second duct  12  has a sleeve  121  to couple with the tube  112  and the ventilation opening  122  extended from the sleeve  121 . The tube  112  has a plurality of helical grooves  113  formed on the outer wall. The sleeve  121  has a bulged element  123  on the inner wall corresponding to and engageable with the helical grooves  113  to couple the first duct  11  and the second duct  12 .  
         [0019]     The adjusting member  13  is pivotally coupled with the second duct  12  through the second coupling means to generate a relative movement between the adjusting member  13  and the second duct  12 . The second coupling means includes a latch member  124  located on one end of the ventilation opening  122 . The latch member  124  has a strut  125  in the middle portion and two latch arms  126  on two sides. The adjusting member  13  has a housing compartment  131  to hold the latch member  124  that has a trough  132  matching the strut  125  and teeth racks  133  matching the latch arms  126 . The latch member  124  may be inserted into the housing compartment  131  with the strut  125  wedging into the trough  132  and the latch arms  126  engaging with the teeth racks  133  to couple the second duct  12  with the adjusting member  13 . The adjusting member  13  further has a pair of hooks  135  to couple on the sliding track  21  of the computer case  20  to brace the air duct assembly  10  without sinking under its own weight.  
         [0020]     In addition, the strut  125  has an aperture  127  and the trough  132  has a slot  136  that may be coupled by a fastening element  16  to increase the coupling strength between the adjusting member  13  and the latch member  124 .  
         [0021]     Referring to  FIGS. 3A, 3B  and  3 C, when in use the adjusting member  13  may be moved horizontally on the sliding track  21  to a desired location, then a fastening element  15  may be inserted through the fastening slot  134  to engage with a selected fastening hole  211  of the sliding track  21 . Through the second coupling means, the latch member  124  may be moved outwards from the housing compartment  131  to move the latch arms  126  on the teeth racks  133  until reaching a desired location to latch the latch arms  126  on the teeth racks  133 . Therefore the relative position of the second duct  12  and the adjusting member  13  may be adjusted.  
         [0022]     Refer to  FIGS. 4A and 4B  for the movement of the first duct and the second duct. Through the first coupling means, the second duct  12  may be moved outwards to allow the bulged element  123  to move from one the helical groove  113  of the tube  112  to another helical groove to adjust the relative position of the first duct  11  and the second duct  12 .