Patent Publication Number: US-2010124844-A1

Title: Structural improvement of electromagnetic interference shielding device for card connector

Description:
BACKGROUND OF THE INVENTION 
     (a) Field of the Invention 
     The present invention relates to an improved structure of a PC card slot, and more particularly to an improved structure of an expansion card slot suitable for increasing electromagnetic interference noise-derived contact points so as to have a shorter path to direct the noise to the ground, thus enhancing the electromagnetic interference shielding effect. 
     (b) Description of the Prior Art 
     With the development of the times, various electronic products and electrical appliances have come into the lives of modern people, so the electromagnetic radiation appears all around our environment. Not only the electromagnetic radiation of these electromechanical and electronic devices causes injury to human bodies, but it also becomes the interference noise between the devices, thereby influencing the satisfaction thereof and in a work environment and of the expected functions. Accordingly, the overwhelming majority of electromechanical and electronic devices are provided therein with electromagnetic interference shielding devices to shield and block the electromagnetic interference. 
     Various card connectors mostly also have such kinds of electromagnetic interference shielding devices. Referring to  FIG. 1 , illustrated is a schematic three-dimensional assembly drawing of a structure of an electromagnetic interference shielding device for a card connector of the prior art. As illustrated in the figure, a card connector  10  is formed by assembling a base  100  of the card connector and an electromagnetic interference shielding device  150 . The base  100  of the card connector has a receiving space  110  therein for receiving at least one PC card (not shown). The base  100  of the card connector further has a docking device (not shown) located adjacent to the receiving space  110  for connecting the PC card. A grounding member  120  is formed by extending downwardly from each of the two sides of the docking device. 
     The electromagnetic interference shielding device  150  is comprised of a grounding iron sheet  160 , an upper iron case  170  and a shielding iron case  180 . The grounding iron sheet  160  covers and is connected with the docking device to derive the electromagnetic noise therefrom so that the electromagnetic noise is transferred to the shielding iron case  180  through the connection of the upper iron case  170  with the shielding iron case  180 . 
     Referring to  FIG. 2 , illustrated is a partial three-dimensional assembly drawing of a structure of an electromagnetic interference shielding device for a card connector of the prior art. As illustrated in the figure, the shielding iron case  180  itself further comprises bayonet portions  181 , upper grounding fins  182  and grounding spring plates  183 . The bayonet portions  181  engage with the base  100  of the card connector so that the shielding iron case  180  can cover the base  100  of the card connector to block the external electromagnetic waves. The grounding fins  182  and the grounding spring plates  183  are respectively connected to the two ends of the grounding member  120  to form two contact points on each of the two sides of the shielding iron case  180 . Thus, the electromagnetic noise can be derived from the above contact points. 
     The structure of an electromagnetic interference shielding device for a card connector of the prior art is a three-piece structure and only four contact points are formed, thus resulting in many drawbacks such as poor conduction efficiency, higher costs and the device of a too complicated structure. An objective of the present invention is to provide an improved structure, and it is expected that the noise conduction efficiency can be increased at the same time as the manufacturing cost can be decreased using a simple structure so as to solve the problems of the structure of an electromagnetic interference shielding device for a card connector of the prior art. 
     SUMMARY OF THE INVENTION 
     The present invention is mainly to provide a structural improvement of an electromagnetic interference shielding device for a card connector, and more particularly to provide a one-piece electromagnetic interference shielding device with grounding holders in place of a three-piece electromagnetic interference shielding device of the prior art. 
     A structural improvement of an electromagnetic interference shielding device for a card connector according to the present invention comprises a base of the card connector and an electromagnetic interference shielding device. The base of the card connector is an insulated base, comprising a receiving space, a docking device and two male bayonet members. The receiving space is disposed inside the base for receiving at least one PC card. The docking device is located inside the base and at the side adjacent to the receiving space. The docking device at least comprises a set of terminals and two ground straps therein. The set of terminals is electrically connected with the PC card, and the ground straps are respectively located at the appropriate positions on the two sides of the docking device, each of the ground straps being of a strip-like structure and extending from the docking device downwardly to the ground. The one ends of the ground straps are connected to the docking device and the other ends extend downwardly to the ground. The two male bayonet members are respectively located at the two outer sides of the base and close to the docking device. 
     The electromagnetic interference shielding device is an L-shaped cover of a metallic material to shield the docking device of the base of the card connector, comprising two female bayonet members, at least two grounding guide spring plates, two upper grounding fins and two grounding holders, and all the above elements are formed as one piece with the L-shaped cover. The two female bayonet members are respectively formed on the two side surfaces of the cover and located corresponding to the two male bayonet members of the base of the card connector to engage with the two male bayonet members. The one ends of the grounding guide spring plates are connected with the PC card; the other ends are connected with the ground straps through the upper grounding fins. The upper grounding fins are respectively disposed on the two sides of the cover and located corresponding to the ground straps of the docking device. The grounding holders respectively extend downwardly from the two ends of the cover and form an inverted U-shaped structure with the cover, and the grounding holders are respectively formed with first holding portions and second holding portions that inwardly hold the ground straps of the docking device. 
     The advantages and spirit of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings. The drawings are only for reference and illustrative purposes, and thus are not intended to limit the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic three-dimensional assembly drawing of a structure of an electromagnetic interference shielding device for a card connector of the prior art. 
         FIG. 2  is a partial three-dimensional assembly drawing of a structure of an electromagnetic interference shielding device for a card connector of the prior art. 
         FIG. 3  is a schematic three-dimensional exploded view showing a structural improvement of an electromagnetic interference shielding device for a card connector according to a preferred embodiment of the present invention. 
         FIG. 4  is a schematic three-dimensional partial view showing a structural improvement of an electromagnetic interference shielding device for a card connector according to a preferred embodiment of the present invention. 
         FIG. 5  is a partial front view showing a structural improvement of an electromagnetic interference shielding device for a card connector according to a preferred embodiment of the present invention. 
         FIG. 6  is a schematic three-dimensional assembly drawing showing a structural improvement of an electromagnetic interference shielding device for a card connector according to a preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will become apparent from the following detailed description of the preferred embodiment taken in conjunction with the accompanying drawings. Referring to  FIG. 3 , illustrated is a schematic three-dimensional exploded view showing a structural improvement of an electromagnetic interference shielding device for a card connector according to a preferred embodiment of the present invention. As illustrated in the figure, a card connector  20  comprises a base  200  of the card connector and an electromagnetic interference shielding device  250 . The base  200  of the card connector is an insulated base and is formed therein with a receiving space  210 . In addition, the base has a docking device  220  located at one side of the base  200  and adjacent to the receiving space  210 , and there are two male bayonet members  230  respectively located at the two outer sides of the base  200  and close to the docking device  220 . 
     The receiving space  210  is located inside the base  200  for receiving at least one PC card (not shown). The docking device  220  is located inside the base  200  and at the side adjacent to the receiving space  210 , which further comprises a set of terminals  221  and two ground straps  222  therein. The set of terminals  221  can be electrically connected with the PC card, and the ground straps  222  are respectively located at the appropriate positions on the two sides of the docking device  220 , each of the ground straps being of a strip-like structure and extending from the docking device  220  downwardly to the ground. The one ends of the ground straps  222  are connected to the docking device  220  and the other ends extend downwardly to the ground. 
     The electromagnetic interference shielding device  250  is an L-shaped cover of a metallic material to shield the docking device  220  of the base  200  of the card connector. The electromagnetic interference shielding device  250  comprises two female bayonet members  251 , at least two grounding guide spring plates  252 , two upper grounding fins  253  and two grounding holders  260 , and all the above elements are formed as one piece with the electromagnetic interference shielding device  250 . However, in this embodiment, eight guide spring plates  252  are provided, which meets the requirement of at least two guide spring plates  252 . 
     The two female bayonet members  251  are respectively formed on the two side surfaces of the cover of the electromagnetic interference shielding device  250  and located corresponding to the two male bayonet members  230  of the base  200  of the card connector to engage with the two male bayonet members  230 . The one ends of the grounding guide spring plates  252  are connected with the PC card; the other ends are connected with the ground straps  222  through the upper grounding fins  253 . 
     The upper grounding fins  253  are respectively disposed on the two sides of the cover of the electromagnetic interference shielding device  250  and located corresponding to the ends of the ground straps  222  that are connected to the docking device  220 . The grounding holders  260  respectively extend downwardly from the two ends of the cover of the electromagnetic interference shielding device  250  and form an inverted U-shaped structure with the cover, and the grounding holders  260  are respectively formed with first holding portions  261  and second holding portions  262  that inwardly hold the grounding straps  222  of the docking device  220 . 
     Referring to  FIGS. 4 and 5 , illustrated are a schematic three-dimensional partial view and a partial front view showing a structural improvement of an electromagnetic interference shielding device for a card connector according to a preferred embodiment of the present invention. It will be apparent from the figures the relationship and positions of the grounding holders  260  and the grounding straps  222  of the docking device  220  of the electromagnetic interference shielding device  250  according to the present invention. As illustrated in the figures, the front end of the grounding holder  260  is folded at 90 degrees and divided into two holding portions that are the first holding portion  261  and the second holding portion  262  respectively. The front ends of the two holding portions protrude and are in point contact with the two side surfaces of the grounding strap  222  respectively, thus forming two contact points to direct the noise to the ground more rapidly. 
     Referring to  FIGS. 3 and 6 , illustrated are a schematic three-dimensional exploded view and a schematic three-dimensional assembly drawing showing a structural improvement of an electromagnetic interference shielding device for a card connector according to a preferred embodiment of the present invention. As illustrated in the figures, the card connector  20  is formed by combining the base  200  of the card connector with the electromagnetic interference shielding device  250 , wherein the electromagnetic interference shielding device  250  at its two sides has the two female bayonet members  251  that engage with the two male bayonet members  230  on the two sides of the base  200  of the card connector so that the electromagnetic interference shielding device  250  can shield the docking device  220 . Because the electromagnetic interference shielding device  250  is formed as one piece, the at least two grounding guide spring plates  252 , the two upper grounding fins  253  and the two grounding holders  260  of the electromagnetic interference shielding device  250  and the set of terminals  221  and the two ground straps  222  of the docking device  220  can be connected with each other at the same time. The two ends of the ground strap  222  are connected with the upper grounding fin  253  and the grounding holder  260  respectively. More contact points can be used to remove the electromagnetic interference noise through the ground more rapidly and in a shorter path by such design and connection. 
     In summarization of the foregoing description, it should be known that the present invention possesses industrial utilization, novelty and inventiveness and meets the requirements for a utility model patent. However, it should be understood that the embodiments of the present invention described herein are merely exemplary and that various variations and modifications can be made to the described embodiments without departing from the scope of the invention. All such equivalent variations and modifications are intended to be included within the scope of the invention as defined by the appended claims.