Abstract:
An air filter assembly is useful with an external hard drive, a computer housing and memory storage device housings. The air filter assembly includes a frame, an air filter, and a retainer for slidably holding the air filter in the frame. Air filter deformation may result in captured dust and particulate matter dropping from the filter. The retainer of the present invention is specially configured for preventing filter deformation and dusty messes.

Description:
FIELD OF THE INVENTION 
     The present invention pertains to cooling devices for hard disk drives and more particularly to removable filter assemblies for use with cooling fans. 
     BACKGROUND OF THE INVENTION 
     U.S. Pat. No. 5,673,029 (&#39;029 patent) discloses an Apparatus for Cooling a Memory Storage Device, the disclosure of which is incorporated herein by reference. The apparatus includes fans mounted on a bezel for drawing air through a memory storage device bay of a computer or a memory storage device housing. Drawing air through the bay is intended to cool a hard disk drive mounted in the bay, and to cool the housing. Using air to cool hard drives reduces the risk of data loss due to heat related hard drive failure. 
     Air may contain particulate matter such as dust and the like. Over time, dust may build up on electronic components within the computer housing. Using a fan to continually draw into the housing may accelerate the dust buildup. It is common for dust may build up on a motherboard, hard drive controller, video card, power supply, or other electronic components. Excessive dust buildup on an electronic component may enable the dust to conduct current, causing the component to short. What is desired is a way to improved electronic component reliability by reducing the amount of dust that enters the computer housing. 
     To remedy the problems associated with dust and particulate matter, filters are typically integrated with hard drive cooling kits to filter incoming air. Unfortunately, filters may become plugged after extensive use. A plugged filter should be removed, cleaned and replaced to maximize airflow through the filter. The &#39;029 patent describes a bezel for holding an air filter, and an oval shaped cover that snaps on to the bezel to hold the air filter. The filter is flexible. When the filter is full of dust, removal of the filter may flex the filter and cause dust to fall from the filter. The dust may be drawn into the memory storage device housing, or fall on a desktop or floor, for example. Accordingly, what is desired is an improved system of filter removal and replacement that can ease filter replacement and reduce undesired mess associated with filter removal. 
     SUMMARY OF THE INVENTION 
     An air filter assembly is useful with any housing for electronic components. The air filter assembly is particularly adapted for use with computer and memory storage device housings having connective cooling. The air filter assembly includes a frame, an air filter, and a retainer for slidably holding the air filter in the frame. The retainer inhibits spillage of dust and particulate matter from the filter during filter removal. 
     The frame has an inlet, an outlet and two lateral sides. One lateral side includes a hinge connectable with the memory storage device bay, the other lateral side defines an opening to enable insertion and removal of the air filter. The frame has an inner periphery with grooves for receiving the retainer the air filter. The opening of the frame aligns with the grooves to enable the retainer and air filter to slide into the grooves. It can be appreciated that while grooves are integrated with the frame, that grooves can also be formed on the retainer to enable the retainer to mate with the frame. 
     The retainer has two sides and flexible joint to move the sides between an open configuration to a closed configuration. In the closed configuration, the sides of the retainer sandwich the air filter to hold the air filter. Each side has edges that rack in the grooves of the frame to insert the retainer in the frame when the retainer is in the closed configuration. 
     According to one aspect of the invention, the flexible joint of the retainer spring biases the retainer in the open configuration to press the retainer edges against the grooves of the frame when the retainer inserts into the frame. 
     The sides of the air filter have an inner face and an outer face that coincide with the inlet and outlet of the frame, respectively, when the filter inserts into the frame. The sides of the retainer surround the inner face and the outer face of the air filter. Preferably, the sides of the retainer form a grate to provide rigidity to the faces of the air filter without significantly inhibiting air flow through the filter. 
     According to an aspect of the invention where the invention is used to filter air flowing through a memory storage device bay, the frame and the air filter are rectangular shaped to fully cover the memory storage device bay. Preferably the retainer is fabricated from a spring material such as steel or other metal to firmly hold the filter while air turbulently flows through the air filter. 
     Removal of the air filter is periodically useful to facilitate cleaning of the air filter. The present invention enables removal and replacement of the air filter without making a dusty mess. The present invention also protects the air filter during and after air filter removal. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows the present invention used in a computer housing. 
     FIG. 2 shows the present invention being inserted into a removable memory storage device carrier. 
     FIG. 3 shows the present invention on an external hard disk drive housing. 
     FIG. 4 shows a perspective view of a memory storage device tower employing the present invention. 
     FIG. 5 shows an exploded view of the invention in accordance with FIG.  4 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a computer housing generally designated with the reference numeral  10 . The computer housing  10  has multiple memory storage device bays  12 , hard disk drives  14 , and hard drive cooler assemblies  16  mounted in the memory storage device bays  12 . 
     The hard drive cooler assembly  16  includes fans  22 , a frame  34 , and an air filter assembly  18 . Each fan  22  mounts in a memory storage device bay  12 . The frame  34  is hinged to the memory storage device bay  12  and includes a portion that functions as a door to swing from an open position to a closed position. In the closed position, the frame  34  lies flush with the computer housing  10  to cover the memory storage device bay  12 , protecting the fans  22 . In the open position, the frame  34  extends at an oblique angle with respect to the memory storage device bay  12  exposing the fans  22  and enabling removal of the air filter assembly  18  from the frame  34 . The frame enables removal of the hard drive  14  from the housing  10  when the frame is in the open position. 
     It can be appreciated that although the present invention is used in a computer housing  10 , the present invention can be used in conjunction with a RAID tower or other memory storage device housing, for example. Further, while the present invention is presented in combination with a hard drive cooler assembly, the present invention can also be used without fans. 
     FIG. 2 shows a portion of the computer  10  housing of FIG. 1. A carrier  30  and rack  32  removeably mount the hard drive  14  within the housing  10 . The rack  32  is fixed in the memory storage device bay  12 . The hard disk drive  14  is fixed in the carrier  30 . The carrier  30  slides in an out of the rack  32  to insert and remove the hard disk drive  14  from the computer housing  10 . 
     The air filter assembly  18  of the present invention includes the frame  34 , an air filter  38 , and a retainer  36 . The retainer  36  holds the air filter  38  in the frame  34 . The retainer  36  is specially configured to enable removal of the air filter  38  without deforming the air filter  38 . Deformation of the air filter  38  when it is filled with dust can cause the dust to fall out of the filter  38  and possibly enter the housing  10 . Accordingly the present invention keeps a memory storage device housing relatively dust free by minimizing filter deformation during operation and handling. 
     The frame  34  is configured to hold the retainer  36  and allow easy removal and installation of the retainer  36 . The frame  34  has an air inlet  40 , an air outlet  42  and two lateral sides  44  and  46 . The inlet  40  and outlet  42  enable airflow through the frame  34  to cool the memory storage device bay. One lateral side  44  includes a hinge  48  for mounting the frame  34  on the memory storage device bay  12 . The other lateral side  46  defines an opening  52  for receiving the retainer  36  and the air filter  38 . The frame  34  firmly holds the retainer  36  and the air filter  38  during operation of the fans  22  to prevent filter  38  deformation resulting from fan-induced turbulent air flow. 
     The frame  34  swings about the hinge  48  between an open position and a closed position. In the open position, the frame  34  unlocks the carrier  30  from the rack  32  and the frame  34  extends at an oblique angle from the housing  10 . When the carrier  30  unlocks from the rack  32 , the hard drive  14  may be removed from the computer system  10 . Additionally, when the frame  34  swings to the open position, the air filter  38  and retainer  36  are simultaneously removable from the frame  34 . Simultaneous removal of the retainer  36  and the air filter  38  helps to prevent dust from escaping from the air filter  38 . 
     The frame  34 , the retainer  36  and the air filter  38  are rectangular shaped to fully cover a memory storage bay  12  having a rectangular opening. The air filter  38  is flexible and has a front face  54  and a rear face  56  that coincide, respectively with the inlet  40  and outlet  42  of the frame when the air filter assembly  18  inserts into the frame  34 . The air filter  38  is made from a porous material to trap dust. 
     The retainer  36  has two sides  50  and  51  and a flexible joint  62  between the sides that folds to enable the retainer  36  to and surround at least a portion of each of the two faces  54  and  56  of the air filter  38 . Preferably, the retainer  36  sandwiches the air filter  38  to hold the air filter  38  and to provide rigidity to the air filter  38 . The flexible joint  62  enables the retainer  36  to fold between an open configuration where the air filter  38  may be replaced, to a closed configuration where the retainer  36  sandwiches the air filter  38 . The flexible joint  62  spring biases the retainer  36  in the open configuration so that the retainer  36  firmly presses outward against the frame  34  to hold the air filter  38  in the frame  34 . 
     The retainer  36  sandwiches the air filter  38  to insert the filter  38  into the frame  34  via the opening  52  in the lateral side  46  of the frame  34 . When the retainer  36  inserts the air filter  38  into the frame  34 , and when the retainer  36  holds the air filter  38  in the frame  34 , the frame  34  presses the sides of the retainer  36  against the faces  54  and  56  of the air filter  38 . Pressing the sides of the retainer  36  with the frame  34  minimizes filter  38  deformation. 
     Removal of the retainer  36  from the frame  34  is accomplished by pressing the sides of the retainer  36  together to release pressure between the retainer  36  and the frame  34 . Pressing the sides of the retainer  36  together holds dust in the air filter  38  to inhibit dust spillage during air filter removal. The retainer  36  provides rigidity to the air filter  38  to further ease removal of the air filter  38  from the frame  34 . The retainer  36  optionally provides rigidity and protection to the air filter  38  during air filter  38  cleaning. 
     According to an aspect of the invention, the sides of the retainer  36  form a grate to improves rigidity of the air filter  38  and thereby inhibits spillage of dust from the air filter  38  during air filter  38  removal. The grate also protects the air filter  38  from damage. 
     The frame  34  has an inner periphery with top and bottom grooves  66 . The retainer has a top edge  68  and a bottom edge  68 . The groves  66  of the frame  34  enable the edges  68  of the retainer  36  to smoothly mate with the grooves  66  and slide with respect to the frame  34 . Smoothly mating the edges  68  of the retainer  36  and the grooves  66  of the frame  34  minimizes friction between the frame  34  and the retainer  36 . Reducing friction enables the retainer  36  to be removed smoothly from the frame  34  to minimize dust spillage. Mating between the edges  68  of the retainer  36  and the grooves  66  of the frame  34  also provides rigidity to the air filter  38  so that the air filter  38  will not deform, tear or contact the fans  22  during removal. 
     FIG. 3 shows an external hard drive housing  70 . The frame  34  mounts on one side of the housing  70  to hold the retainer  36  and the air filter  38 . 
     It can be appreciated that the configuration of the retainer can be varied in many ways without departing from the scope of the present invention. For example, the retainer can fully surround the filter. Additionally, the grate-shaped sides of the retainer may be re-configured for aesthetics and for function. The size of the grate openings can be changed to inhibit dust from entering the housing upon removal of the air filter assembly  18 . 
     FIG. 4 shows a memory storage device housing  80  having a face  82  and multiple memory storage device bays  12 . The air filter assembly  18  covers multiple bays  12  and a significant portion of the face  82  of the memory storage device housing  80 . 
     FIG. 5 shows the memory storage device housing  80  and the air filter assembly  18 . The frame  34 , the air filter  38  and the retainer  36  are sized large enough to cover multiple memory storage device bays  12 .