Patent Publication Number: US-2013250540-A1

Title: Shielding shell

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a shielding shell, and more particularly to a shielding shell mounted on a circuit board for shielding electromagnetic interference. 
     2. The Related Art 
     With the wide use of electronic equipments in our daily life, electromagnetic waves are everywhere and often form a potential interference source that affects electrical circuits of the electronic equipments easily. The electromagnetic interference is a kind of electromagnetic phenomenon produced along with the change of electrical currents and voltages. The electromagnetic interference may interrupt, obstruct, or otherwise degrade or limit the effective performance of the electrical circuit. These effects can range from a simple degradation of data to a total loss of data. A common means of reducing the electromagnetic interference is: fixing or soldering a shielding shell on a printed circuit board for shielding the electromagnetic interference. However, if a repair operation needs to be performed for electronic components on the printed circuit board, it is an inevitable procedure to remove the shielding shell from the printed circuit board by damaging or disoldering the shielding shell. As a result, not only this procedure is very inconvenient, but also the shielding shell may be easily damaged in the process of being disoldered or should be directly damaged. So, it not only causes material waste, but also takes a long time of repair work hours, and finally fails to effectively achieve human and material cost control. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a shielding shell adapted for being mounted on a printed circuit board to surround electronic components of the printed circuit board for shielding electromagnetic interference. The shielding shell includes a frame and a cover. The frame has a ring-shaped bracket with a receiving chamber therein. The bracket is erected on the printed circuit board with the electronic components located in the receiving chamber. A top periphery of the bracket bends inward to form a support eave which is parallel to a top face of the printed circuit board and slightly higher than the peak of a highest electronic component. At least three restricting portions of inverted-L shape protrude upward and then inward at a rear and two symmetrical sides of the top periphery of the bracket respectively. An inserting slot is formed between the restricting portion and the support eave. The cover has a cover plate of which an outline is substantially in accordance with the bracket and an area is slightly greater than the receiving chamber. The cover plate is movably located on the support eave through a front of the frame and further pushed rearward to be inserted in the inserting slots so as to removably cover up the receiving chamber. 
     As described above, the cover is removably assembled to the frame so that not only can completely enclose the electronic components of the printed circuit board in the shielding shell to effectively shield the electromagnetic interference, but also can conveniently repair the electronic components by removing the cover from the frame to expose the electronic components outside, without damaging the frame and the cover. So, it not only effectively economizes material waste, but also greatly improves repair efficiency, and finally effectively realizes human and material cost control. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be apparent to those skilled in the art by reading the following description with reference to the attached drawings, in which: 
         FIG. 1  is an exploded perspective view of a shielding shell in accordance with an embodiment of the present invention; and 
         FIG. 2 ,  FIG. 3  and  FIG. 4  are using state views showing that the shielding shell of  FIG. 1  is assembled on a printed circuit board. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 1  and  FIG. 2 , a shielding shell  1  according to an embodiment of the present invention is adapted for being mounted on a printed circuit board  4  to surround electronic components  41  of the printed circuit board  4  therein for shielding electromagnetic interference. The shielding shell  1  includes a frame  2  and a cover  3 . 
     Referring to  FIGS. 1-4 , the frame  2  has a ring-shaped bracket  200  with a receiving chamber  20  therein. The bracket  200  is erected on the printed circuit board  4  with the electronic components  41  located in the receiving chamber  20 . A top periphery of the bracket  200  bends inward to form a support eave  22  which is parallel to a top face  42  of the printed circuit board  4  and slightly higher than the peak of the highest one of the electronic components  41 . At least three restricting portions  21  of inverted-L shape protrude upward and then inward at a rear and two symmetrical sides of the top periphery of the bracket  200  respectively. An inserting slot  210  is formed between the restricting portion  21  and the support eave  22 . The cover  3  has a cover plate  31  of which an outline is substantially in accordance with the bracket  200  and an area is slightly greater than the receiving chamber  20 . The cover plate  31  is movably located on the support eave  22  through a front of the frame  2  and further pushed rearward to be inserted in the inserting slots  210  so as to removably cover up the receiving chamber  20 . So, the shielding shell  1  can completely enclose the electronic components  41  of the printed circuit board  4  therein to effectively shield electromagnetic interference. When some electronic components  41  need to be repaired, pull the cover  3  forward until the cover plate  31  moves out of the inserting slots  210 . At this moment, remove the cover  3  from the frame  2  so as to expose the electronic components  41  outside for the convenience of the repair operation. 
     Referring to  FIG. 1  and  FIG. 4 , the bracket  200  defines a pair of latching structures  211  at two fronts of two opposite sides thereof. A pair of latching arms  321  is freely located at two opposite sides of a front of the cover plate  31  and each defines a latching portion  322  thereon for buckling with the latching structure  211  of the frame  2  to secure the cover  3  and the frame  2  together. 
     In this embodiment, the bracket  200  is substantially of a rectangular shape and has a front strip  201 , two opposite side strips  203  and a rear strip  202 . The top periphery of the side strips  203  and the rear strip  202  each protrudes to form two restricting portions  21 . The latching structures  211  form at two front ends of the side strips  203 . The cover plate  31  is of a flat rectangular board shape and a front edge thereof bends downward to form a resisting strip  32  of which two opposite ends extend rearward to form the latching arms  321 . 
     Referring to  FIGS. 1-4  again, a support cross  23  is connected with an inner periphery of the support eave  22  of the frame  2  and located over the receiving chamber  20  for strengthening the support eave  22  of the frame  2  and further bearing the cover plate  31  thereon. In this embodiment, the frame  2  and the cover  3  are made of metal material. 
     As described above, the cover  3  is removably assembled to the frame  2  so that not only can completely enclose the electronic components  41  of the printed circuit board  4  in the shielding shell  1  to effectively shield the electromagnetic interference, but also can conveniently repair the electronic components  41  by removing the cover  3  from the frame  2  to expose the electronic components  41  outside, without damaging the frame  2  and the cover  3 . So, it not only effectively economizes material waste, but also greatly improves repair efficiency, and finally effectively realizes human and material cost control.