Abstract:
A shielding apparatus for electromagnetic testing includes a platform, a lid forming a cavity, a driving unit, and an elastic gasket attached to a bottom of the lid around a rim adjacent the cavity. The platform is for placing an electronic device to be tested. The lid is for covering the platform to define a closed space. The driving unit is for lifting and lowering the lid. The gasket is for being compressed and filling gaps between the lid and the platform when the platform covers the lid.

Description:
BACKGROUND 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to shields for protecting electronic equipments from electromagnetic interference, and particularly to a shielding apparatus for electromagnetic testing. 
         [0003]    2. Description of related art 
         [0004]    Electronic devices such as cellular telephones and notebook computers, etc. are always tested before being sold to the public so as to ensure quality assurance of the electronic devices. Testing these electronic devices requires electromagnetic shielding in order to protect the electronic products from interference with outside electromagnetic waves, such as radio frequency (RF) waves. 
         [0005]    Traditionally, a shield is provided in a form of a shielding box which includes a base and a lid. When the electronic device is tested, the electronic device is placed in the base of the shielded box and the lid is manually placed over the base thereby forming an enclosed space. Within this enclosed space the electronic device is free of interference from outside electromagnetic waves because the base and the lid of the shielding box blocks or absorbs electromagnetic waves. However, in practice, if the lid and the base cannot fit tightly, gaps will exist between the lid and the base when the lid covers the base. Thus, outside electromagnetic waves can pass through the gaps, and the test may be compromised. 
         [0006]    Therefore, a shielding apparatus for electromagnetic testing is needed in the industry to address the aforementioned deficiencies and inadequacies. 
       SUMMARY 
       [0007]    A shielding apparatus for electromagnetic testing includes a platform, a lid forming a cavity, a driving unit, and an elastic gasket attached to a bottom of the lid around a rim adjacent the cavity. The platform is for placing an electronic device to be tested. The lid is for covering the platform to define a closed space. The driving unit is for lifting and lowering the lid. The gasket is for being compressed and filling gaps between the lid and the platform when the platform covers the lid. 
         [0008]    Other systems, methods, features, and advantages of the present shielding apparatus for electromagnetic testing will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional equipments, features, and advantages be included within this description, be within the scope of the present device, and be protected by the accompanying claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Many aspects of the present shielding apparatus and the present shielding apparatus can be better understood with reference to following drawings. Components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present shielding apparatus. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0010]      FIG. 1  is an isometric view of a shielding apparatus in accordance with an exemplary embodiment. 
           [0011]      FIG. 2  is a side view of the shielding apparatus of  FIG. 1 . 
           [0012]      FIG. 3  is a cutaway view of the shielding apparatus of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0013]    Reference will now be made to the drawings to describe a preferred embodiment of the present shielding apparatus. 
         [0014]    Referring to  FIGS. 1 and 2 , a shielding apparatus  100  is used for testing a notebook computer  200  in accordance with an exemplary embodiment. The shielding apparatus  100  includes a hoist  10 , a lid  30 , and a platform  20  extending perpendicularly near a bottom of the hoist  10 . The platform  20  is used for placing the notebook computer  200  to be tested. The platform  20  includes an upper board  22  and a lower board  24 . A bottom shield plate  26  is fixed to a bottom surface (not labeled) of the upper board  22 . The lid  30  forms a cavity  32  (refer to  FIG. 3 ). An elastic gasket  38  is attached to the bottom of the lid  30  around a rim  34  of the lid  30 . The hoist  10  is used for lifting and lowering the lid  30 , thus controlling the lid  30  to rise above the platform  20  or land on the platform  20  to define a closed space. 
         [0015]    The elastic gasket  38  may deform under the weight of the lid  30  and fills any gaps between the lid  30  and the platform  20  when the lid  30  covers the platform  20 , thus blocking outside electromagnetic waves from passing through the gaps between the platform  20  and the lid  30 . The gasket  38  is electrically conductive. The gasket  38  may be consisting of conductive metal, or be consisting of elastomer containing conductive-metallic particles or carbon black, or be consisting of elastomer coated with meshed metal. The gasket  38  can also be made of conductive sponge, etc. 
         [0016]    The hoist  10  includes a supporting structure  14 , a fixed extending arm  16 , a driving unit  40 , a counterbalance  50 , and a pulley system  60 . The arm  16  extends horizontally out from a top of the supporting structure  14 . 
         [0017]    In the embodiment, the pulley system  60  includes a pair of movable pulleys  62 , two pairs of fixed pulleys  64  and a wire  66 . A first pair of fixed pulleys  64  is configured on one end of the arm  16 , and a second pair of fixed pulleys  64  is configured on an outer end of the arm  16 . The pair of moveable pulleys  62  is positioned substantially vertical below the second pair of fixed pulleys  64  above the platform  20 . A bracket  36  is fixed to the pair of movable pulleys  62 . The lid  30  is fixed to the bracket  36 . The wire  66  is preferable a steel wire. The steel wire  66  is folded and the ends of the steel wire  66  are correspondingly inserted through the pulley system  60  and tightly attached to the arm  16 . The counterbalance  50  is hooked to the fold of steel wire  66 . The counterbalance  50  is for partly or substantially counterbalancing the weight of the lid  30  via the pulley system  60 . The movable pulley  62  is adopted for decreasing work needed to lift and lower the lid  30 . A weight of the counterbalance  50  may be equal to or less than half a weight of the lid  30 . 
         [0018]    The driving unit  40  is preferably a pneumatic pump. In other embodiments, a hydraulic pump can be used as a driving unit instead of the pneumatic pump  40 . The pneumatic pump  40  includes a cylinder (not labeled) fixed to a side of the supporting structure  14 , and a piston rod  42  with an end fitting snugly into the cylinder and moves under pneumatic pressure. The other end of the piston rod  42  is fixed to a side of the lid  30 . The pneumatic pump  40  is used for lifting and lowering the lid  30 , thus controlling the lid  30  to rise above the platform  20  or land on the platform  20 . 
         [0019]    The pneumatic pump  40  is controlled by a control panel  70  configured on the platform  20 . When testing the notebook computer  200 , a start button (not labeled) of the control panel  70  is actuated, the pneumatic pump  40  releases the piston rod  42  inwards, and the lid  30  is lowered until it lands on the top of the platform  20  to define the closed space that shields electromagnetic interference. When the test is done, a finish button (not labeled) of the control panel  70  is actuated, the pneumatic pump  40  drives the piston rod  42  outwards to a predetermined height, thus lifting the lid  30  upwards away from the platform  20  and lowering the counterbalance  50 , then, the notebook computer  200  can be removed from the platform  20 . 
         [0020]    As described above, when the lid is lowered onto and covers the platform, the lid compresses the elastic gasket  38  against the platform, thus the elastic gasket  38  forms a seal that plugs up the gaps, if any between the lid  30  and the platform  20 . Furthermore, the elastic gasket  38  impedes interferences from outside electromagnetic waves allowing the test results to be more accurate. In addition, the pulley system  60  and the counterbalance  50  are for partly or substantially counterbalancing the weight of the lid  30 , as a result, the pneumatic pump  40  needs less work to lift the lid  30 , and any injuries due to a force of a landing/falling lid on a user&#39;s hand is also reduced. Thus, the shielding apparatus  100  can prevent serious injuries caused when a user accidentally places his/her hands on the platform  20  in a moving path when the lid  30  lowers/falls. 
         [0021]    Furthermore, in the embodiment, the control panel  70  can include two control units  72 ,  74 . Each of the control units  72 ,  74  includes a start button and a finish button (not labeled). The piston rod  42  lowers only when the two start buttons are actuated at a same time, and raises when one of the start buttons is actuated. The hands of the user would not be hurt by the lid  30  when the lid  30  lowers/falls, as both hands of the user are occupied pressing the two start buttons, thus effectively preventing harm caused by mis-operations. 
         [0022]    Referring to  FIG. 3 , an absorbing layer  80  made of electromagnetic wave absorbing materials is disposed inside the bottom shield plate  26 . The absorbing layer  80  is configured for absorbing electromagnetic waves to enhance the efficiency of shielding. It can be understood that the absorbing layer  80  can also be disposed inside the lid  30 . 
         [0023]    The shielding apparatus  100  also includes a control computer  90  for controlling an electromagnetic test and displaying the result of the electromagnetic test. 
         [0024]    In other embodiments, the pulley system  60  only includes a movable pulley  62  and two fixed pulleys  64  and a wire  66 . One of the fixed pulleys  64  is configured on one end of the arm  16 , and the other fixed pulley  64  is configured on the outer end of the arm  16 . The moveable pulley  62  is configured vertically under the other fixed pulley  64  above the platform. The wire  66  is correspondingly inserted through the pulley system  60 , one of its end is fixed to the arm  16 , and the other end is fixed to the counterbalance  50 . 
         [0025]    It should be emphasized that the above-described preferred embodiment, is merely a possible example of implementation of the principles of the invention, and is merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiment of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and be protected by the following claims.