Abstract:
An electric connector has a housing, signal and ground contacts disposed in the housing and a metal shell surrounding the housing. The metal shell has a support segment covering a top surface of the housing and with a first edge positioned adjacent to a back surface of the housing, and a second edge positioned adjacent to a front surface of the housing. The ground contacts are formed integral with and extend forwardly from the second edge of the support segment by a one-step stamping process.

Description:
This application claims priority from Taiwan patent application number 095143680, filed on 24 Nov. 2006, entitled “ELECTRIC CONNECTOR”, which is hereby incorporated by reference. 
     TECHNICAL FIELD 
     The present invention relates to an electric connector, and more particularly to an electric connector having a metal shell serving as a grounding shield. 
     BACKGROUND 
     Electric connectors are used to establish electrical connections between electronic devices and systems. With the increasing requirements on system integration and minimization, electric connectors are arranged in the electronic systems more and more close to each other, and transmitting electronic signals with higher signal transmission speed. As a result, the electromagnetic interference between the neighboring electric connectors and the external electromagnetic radiation are greatly increased, which may adversely influence the signal transmitting quality. 
     To reduce or eliminate the electromagnetic interference, a metal shell may be arranged outside the electric connector, which can serve as grounding shield for the connector. To ground a mating counterpart connector, grounding contacts are also provided on the metal shell and for connecting to the counterpart connector. 
     Persons skilled in the art would appreciate that the positional coplanarity of the signal contacts and the grounding contacts in the electric connector will affect the ultimate performance. However, the manufacturing of known electric connectors of this type has a problem in that, the coplanarity of the signal contacts and grounding contacts are difficult to be ensured. The unsatisfactory coplanarity of the contacts may cause a non-uniform contact pressure between each contact and the counterpart connector, and even causes poor or fail contacts. 
     It is therefore desirable to provide an electric connector that has a satisfactory performance, is easy to manufacture and having contact terminals with ensured coplanarity. 
     SUMMARY OF THE INVENTION 
     Accordingly, an objective of the present invention is to provide an electric connector, which is easy to manufacture and has parts with high accuracy. 
     Another objective of the present invention is to provide an electric connector, which has a metal shell that is easy to manufacture and grounding contacts of preferred coplanarity. 
     A further objective of the present invention is to provide an electric connector, which has a low cost and a fast manufacturing process. 
     As embodied and broadly described herein, the present invention provides an electric connector, which comprises a housing, a plurality of signal contacts, and a metal shell. The housing comprises a body having a first wall, a second wall opposite to the first wall, and a space formed between the first wall and the second wall for receiving a counterpart connector, a plurality of upper grooves formed on a first inner surface of the first wall, a plurality of lower grooves formed on a second inner surface of the second wall, and a recess formed on an outer rear surface of the housing in which the recess is communicating with the space through the upper grooves. The signal contacts are disposed in the lower grooves of the housing. The metal shell comprises a frame portion encompassing the housing and an inwardly deformed portion. The inwardly deformed portion integrally connects the frame portion by means of a bent portion and is recessed downwardly with respect to the frame portion. The inwardly deformed portion comprises a straight portion embedded in the recess of the housing and a plurality of grounding contacts extending from the straight portion and inserting into the upper grooves. 
     In one embodiment, each of the grounding contacts of the metal shell comprises a contact portion for contacting the counterpart connector to ground, and a spring portion coupled to the contact portion to elastically move the contact portion. 
     In another embodiment, the metal shell further comprises at least one folding portion extending from the frame portion and folded inwardly into the frame portion to be engaged with at least one side wall of the housing. The housing further comprises a plurality of holes, and the frame portion of the metal shell further comprises a plurality of first protruding portions for inserting into the holes to fax the metal shell and the housing together. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of an electric connector according to one embodiment of the present invention; 
         FIG. 2  is a perspective front side view of the housing of a connector shown in  FIG. 1 ; 
         FIG. 3  is a perspective rear side view of  FIG. 2 ; 
         FIG. 4A  is a perspective view of the metal shell of a connector shown in  FIG. 1 ; 
         FIG. 4B  is a perspective front view of a connector shown in  FIG. 1  when assembled together; 
         FIG. 4C  is a perspective rear view of  FIG. 4B ; 
         FIG. 5  is a partial enlarged view of  FIG. 4A ; 
         FIG. 6  is a perspective view of an electric connector of  FIG. 1  when mounted to a circuit board; 
         FIG. 7  is a perspective rear view of  FIG. 6 ; 
         FIG. 8  is a partial cross-sectional view of an electric connector of  FIG. 1  when connected to a counterpart connector; 
         FIG. 9  is a partial cross-sectional view of an electric connector according to another embodiment of the present invention and when connected to a counterpart connector. 
         FIG. 10  is a perspective view showing a metal shell for an electric connector according to a further embodiment of the present invention; and 
         FIG. 11  is a perspective view showing a housing for assembling with the metal shell shown in  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1  and  FIG. 2 , an electric connector  1  according to one embodiment of the present invention includes a housing  10 , a plurality of signal contacts  20  to be disposed in housing  10 , and a metal shell  30  which provides a grounding shield for connector  1 . Housing  10  has a first wall  101 , a second wall  102  opposite to first wall  101 , two side walls  103 , and a rear wall  104 . A space or slot  105  is formed between the first wall  101  and the second wall  102  for receiving a counterpart connector (not shown). 
     First wall  101  has a first inner surface  106  with a plurality of upper grooves  107  formed thereon. Second wall  102  has a second inner surface  108  with a plurality of lower grooves  109  formed thereon. Housing  10  further comprises a plurality of holes  110 . 
     As shown in  FIG. 3 , an elongated recess  112  is formed on an outer rear surface  111  of the rear wall  104  of housing  10  in which the recess  112  is communicating with space  105  through upper grooves  107 . Two ends of recess  112  are respectively formed with a notch  1121  opening to upper surface of housing  10 . 
     Referring to  FIG. 4A , metal shell  30  comprises a frame portion  301  and an inwardly deformed portion  302  which integrally connects to frame portion  301  via link or bent portions  310 . Frame portion  301  has a plurality of first protruding tabs  303  and a plurality of second protruding tabs  304 . Folding portions  305  extending from frame portion  301  and folded inwardly toward frame portion  301  are disposed on both lateral sides of frame portion  301 . Inwardly deformed portion  302  of metal shell  30  is recessed downwardly with respect to frame portion  301 . Inwardly deformed portion  302  comprises a straight portion  306 . When metal shell  30  and housing  10  are assembled together, as shown in  FIGS. 4B and 4C , a first edge  306   a  of straight portion  306  is positioned adjacent to rear surface  111  of housing  10 . A second edge  306   b  of straight portion  306  is positioned away from rear surface  111 . A plurality of grounding contacts  307  are formed integral and extended laterally from second edge  306   b  straight portion  306 , by a one-step stamping or blanking process. 
     As shown in  FIG. 5 , each of grounding contacts  307  comprises a contact portion  308  and a spring portion  309 . Contact portion  308  can be elastically moved up and down with respect to straight portion  307  via spring portion  309 . Grounding contacts  307  are directly supported by straight portion  306  and thus have a high rigidity and strength compared to conventional connectors. Accordingly, grounding contacts  307  have a better durability and deformation resistance. Moreover, metal shell  30  and grounding contacts  307  can be fabricated by one stamping process. This also ensures the coplanarity of grounding contacts  307 . 
       FIGS. 6 and 7  show the front side and the rear side of an electric connector, respectively. The assembling process of the electric connector of the present invention firstly comprises sheathing metal shell  30  onto housing  10  by aligning grounding contacts  307  from the rear side of housing  10  to the plurality of upper grooves  107 , such that frame portion  301  encompasses housing  10 . Meanwhile, grounding contacts  307  are inserted into the plurality of the upper grooves  107 . Straight portion  306  of inwardly deformed portion  302  of metal shell  30  is just embedded into elongated recess  112  at the rear side of housing  10 . Bent or link portion  310  of metal shell  30  is received in notch  1121  at both ends of recess  112 . Folding portions  305  respectively engage with two side walls  103  of housing  10 . First protruding tabs  303  of metal shell  30  are inserted into the plurality of holes  110  of housing  10  to form a press fit, and thus metal shell  30  is fixed to housing  10 . Signal contacts  20  are then inserted into lower grooves  109  of housing  10 , such that signal contacts  20  face grounding contacts  307  in the vertical direction, The assembly of the whole electric connector  1  is completed. 
     Electric connector  1  assembled in the above manner maybe fixed on, for example, a circuit board  40  via the plurality of second protruding tabs  304 . 
     As shown in  FIG. 8 , a counterpart connector  50  is inserted into space  105  of electric connector  1 . A first set of conductive terminals or surfaces  51  of counterpart connector  50  respectively contact each of the signal contacts  20  to establish signal connection. A second set of conductive terminals or surfaces  52  of counterpart connector  50  respectively contact the contact portion  308  of each of the grounding contacts  307 , to establish grounding contacts. Contact portion  308  can be elastically deformed up and down by spring portion  309 , with respect to straight portion  306 , and thus grounding contacts  307  are elastically deformed to force contact portion  308  urging against second set of conductive terminals or metal surfaces  52 . 
     Contact portion  308  may be V-shaped or semicircular in cross section, as shown in  FIG. 9 , and to urge against the second metal surface  52  by the bottom side thereof. Signal contacts  20  may also have a similar construction to be urged against first set of metal surfaces  51 . Signal contacts  20  and grounding contacts  307  can now clamp counterpart connector  50 , thus achieving the complete signal connection and grounding connection. 
     In a further embodiment shown in  FIGS. 10 and 11 , straight portion  406  of a metal shell  430  is not depressed, but is maintained within a same plane as corner portions  401 . Grounding contacts  407  are formed integral of, and extended laterally from, a second edge  406   b  of straight portion  406 . A housing  14  according to this embodiment has a raised center portion at upper surface, with respect to corner portions  14   b . When metal shell  430  and housing  14  are assembled together, straight portion  406  of metal shell  430  is received in a recess  14   c  formed below center portion  14   c . In addition, corner portions  401  of metal shell  430  cover corner portions  14   b  of housing  14 . 
     Advantages of the present invention include, for example, in the structure of the metal shell of the electric connector of the present invention, the straight portion and grounding contacts of the inwardly deformed portion are formed simultaneously through a one-step stamping process. Moreover, since the grounding contacts of the present invention may be accomplished by only one process the grounding contacts still remain a preferred coplanarity and a high yield, such that the grounding contact between the electric connector and the plug connector is good and avoids inefficacy. Another advantage is that, the structure of the metal shell of the electric connector of the present invention has a simple manufacturing process and a high yield, thereby effectively improving the manufacturing efficiency and reducing the manufacturing cost to improve the competition ability. 
     Though the present invention has been disclosed above by the preferred embodiments, they are not intended to limit the present invention. Persons skilled in the art can make modifications and variations without departing from the spirit and scope of the present invention. Therefore, the protecting range of the present invention falls in the appended claims and their equivalents.