Abstract:
An electrical connector includes an insulative housing, a metal shell covering the insulative housing, electrical terminals and auxiliary terminals received in the insulative housing. The electrical terminals includes a number of first contacts. The first contacts include a grounding contact in the middle and some signal contacts on both sides of the grounding contact. The auxiliary terminals includes the retaining portion received in insulative housing and the connecting portion downwardly bent from an end of the retaining portion. The retaining portion has a first spring tab and the connecting has a second spring tab. The first spring tab contacts with the metal shell and the second spring tab contacts with the grounding contact. Such arrangment can improve the anti EMI effect of the electrical connector and reduce the signal interference between the signal terminals.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an electrical connector, more particularly to an electrical connector with grounding element to reduce electromagnetic interference (EMI). 
     2. Description of Related Art 
     China patent issue No. CN202797485U, issued on Mar. 13, 2013, discloses a conventional electrical connector including an insulative housing, a plurality of contacts retained in the insulative housing, and a shell attached to the insulative housing. The shell surrounds the insulative housing to form a mating cavity. The shell has a contact portion extending into the mating cavity forwardly from a top wall thereof The contact portion contacts with a grounding contact. However such arrangement can not well improve the anti-EMI effect of the electrical connector or reduce cross talking between the signal terminals. 
     Hence, an improved electrical connector with improved structure is needed to solve the problem above. 
     BRIEF SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, an electrical connector includes an insulative housing, a metal shell covering the insulative housing, a plurality of electrical terminals and a auxiliary terminal received in the insulative housing. The electrical terminals includes a number of first contacts. The first contacts include a grounding contact in the middle and some signal contacts on both sides of the grounding contact. The auxiliary terminals includes the retaining portion received in insulative housing and the connecting portion downwardly bent from an end of the retaining portion. The retaining portion has a first spring tab and the connecting has a second spring tab. The first spring tab contacts with the metal shell and the second spring tab contacts with the grounding contact. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of an electrical connector in a first embodiment according to the present invention; 
         FIG. 2  is a partially exploded, perspective view of the electrical connector; 
         FIG. 3  is another partially exploded, perspective view of the electrical connector without a shell; 
         FIG. 4  is a cross-sectional view of the electrical connector taken along line  4 - 4  of  FIG. 1 ; 
         FIG. 5  is a partially exploded, perspective view of the electrical connector; 
         FIG. 6  is a similar view to  FIG. 5 , but taken from another aspect; 
         FIG. 7  is an assembled, perspective view of another electrical connector in alternative embodiment according to the present invention; 
         FIG. 8  is a partially exploded, perspective view of the electrical connector in  FIG. 7 ; 
         FIG. 9  is a similar view to  FIG. 8 , but taken from another aspect; and 
         FIG. 10  is a cross-sectional view of the electrical connector taken along line  10 - 10  of  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be obvious to those skilled in the art that the present invention may be practiced without such specific details. In other instances, well-known circuits have been shown in block diagram form in order not to obscure the present invention in unnecessary detail. For the most part, details concerning timing considerations and the like have been omitted inasmuch as such details are not necessary to obtain a complete understanding of the present invention and are within the skills of persons of ordinary skill in the relevant art. 
     Please referring to  FIGS. 1-3 , an electrical connector  100  includes an insulative housing  1 , a plurality of contacts  3  retained in the insulative housing  1 , a shell  2  enclosing the insulative housing  1  and a auxiliary contact  4  assembled to the insulative housing  1 . 
     Please reference to  FIGS. 5-6 , the insulative housing  1  includes a base portion  11 , a tongue portion  12  extending forwardly from the base portion  11  and a spacer  13  retained in a rear of the base portion  11 . The base portion  11  includes a top portion  111 , a bottom portion  112  opposite to the top portion  111  and two side portions  113  connecting with the top portion  111  and the bottom portion  112 . The base portion  11  defines a recess  1111  recessed from a middle of the top portion  111  and two slots  1112  recessed from two sidewalls of the recesses  1111  along a transverse direction of the recess  1111 . The base portion  11  also defines two raises  1121  extending downwardly from the bottom portion  112 . The two side portions  113  have a plurality of ribs  1131  protruding outwardly. The tongue portion  12  includes a top surface  121 , a bottom surface  122  opposite to the top surface  121 , and the bottom surface  122  defines four receiving passageways  1222  in a row and five retaining passageways  1221  in another row and in front of the receiving passageways  1222 . 
     The spacer  13  comprises a body portion  131  and a supporting portion  132  extending forwardly from a bottom of the body portion  131 . The body portion  131  includes a front end face  1311 , two side end faces  1312 , a top end face  1313  and a bottom end face  1314  opposite to the top end face  1313 . The body portion  131  further has a plurality of first contact receiving slots  13131  passing therethrough along an upper to bottom direction. The middle one of the first contact receiving slots  13131  is wider than the other first contact receiving slots  13131 . The body portion  131  has a plurality of retaining blocks  13111  extending downwardly from the top end face  1313  of the body portion  131  to the upper supporting portion  132 . The supporting portion  132  defines a pair of through holes  1321  used for receiving the raises  1121  of the base portion  11  so that the support portion  132  can be firmly assembled to the base portion  11 . The supporting portion  132  also has a plurality of second contact receiving slots  1322  behind the through holes  1321  and in front of the retaining blocks  13111 . 
     Please referring to  FIGS. 1, 5-6 , the shell  2  is stamped from a metal piece and bent to surround the tongue portion  12  to form a receiving room  10 . The shell  2  includes a top wall  21 , a bottom wall  22  opposite to the top wall  21 , two side walls  23  and a rear wall  24 . The rear wall  24  is bent from the side walls  23 . Each of the top wall  21 , the bottom wall  22  and the side walls  23  has one or one pair elastic pieces  211 ,  221 ,  231  protruding into the receiving room  10 , and the top wall  21  further has a resisting arm  212  between the pair of the elastic pieces  211  to strengthen an insertion force with the mating plug (not shown). The two side walls  23  have front retaining legs  232  extending downwardly beyond the bottom wall  22 , and the rear wall  24  has back retaining legs  241  extending downwardly beyond the bottom wall  22  to be mounted on a printed circuit board (not shown). The two side walls  23  further have retaining slots  233  closed to the rear wall  24  and used to cooperate with the ribs  1131  of the base portion  11  so as to strengthen the housing  1  and the shell  2 . 
     Please referring to  FIGS. 4-6 , the contacts  3  comprises a plurality of first contacts  31  insert molded in the insulative housing  1  and a plurality of second contacts  32  assembled to the insulative housing  1  forwardly. Each of the first contacts  31  has a first retaining portion (not shown) retained to the tongue portion  12 , a planar first contacting portion  312  extending forwardly from the first retaining portion (not shown) into the retaining passageways  1221 , and a first connecting portion  313  extending from the first retaining portion (not shown) and downwardly received in the first contact receiving slot  13131  of the spacer  13  and a first soldering portion  314  extending beyond the spacer  13 . The second contact  32  includes a retaining portion  321 , a second contacting portion  322  extending forwardly from the second retaining portion  321 , a second connecting portion  323  extending from the second retaining portion  321  and downwardly received in the second contact receiving slots  1322  and a second soldering portion  324  extending beyond the spacer  13 . 
     The contacts  3  have five first contacts  31  including two pairs of differential signal contacts  34  and a grounding contact  33  between the two pairs. The first connecting portion  313  of the grounding contact  33  is wider than the first connecting portion  313  of the differential signal contacts  34 . The first connecting portion  313  of one of the differential signal contacts  34  closed to the grounding contact  33  is offset along a direction far away from the grounding contact  33  relative to the corresponding first soldering portion  314  to increase a distance between the differential signal contacts  34  with the grounding contact  33  to reduce the signal cross talking between the contacts  3 . 
     Please reference to  FIGS. 2-5 , the auxiliary contact  4  with roughly reverse L-shaped is stamped from a metal piece. The auxiliary contact  4  include a retaining portion  41  horizontally received in the recess  1111  of the base portion  11  and a connecting portion  42  extending downwardly from a rear edge of the retaining portion  41  and received in the spacer  13 . The connecting portion  41  is located behind the first and second connecting portions  313 , 323  of the contacts  3 , the retaining portion  41  is located at a top of the first and second retaining portion  311 ,  321 . The connecting portion  42  of the auxiliary contact  4  and the first connecting portion  313  of the grounding contact  33  are received in a same first contact receiving slot  13131 . The retaining portion  41  is torn to form a first shrapnel  411  elastically contacting against the top wall  21  of the shell  2 . And the connecting portion  42  is torn to form a second shrapnel  421  elastically contacting against the first connecting portion  313  of the grounding contact  33 . The retaining portion  41  further has two latches  412  protruding outwardly and being received in the slots  1112  so as to limit the auxiliary contact  4  to move back and forth. When the shell  2  is assembled to the insulative housing  1 , the first shrapnel  411  elastically contacts against the top wall  21  of the shell  2  so that the shell  2  provides a reactive force to the retaining portion  41  so as to limit the retaining portion  41  and prevent the auxiliary contact  4  from falling off The auxiliary contact  4  electrically connects with the grounding contact  33  to the shell  2  which is reliably grounded, so that electromagnetic interference (EMI) of the electrical connector  100  can be reduced. 
       FIGS. 7-10  discloses another electrical connector  200  in alternative embodiment according to present invention. The electrical connector  200  has a plurality of contacts (not labeled), a shell (not labeled), a spacer  14 , an insulative housing (not labeled) and an auxiliary contact  5 . The electrical connector  200  is substantially same as the connector  100 , but the auxiliary  5  is only attached to the spacer  14 , so the insulative housing does not need to dispose recess or slot for receiving the auxiliary contact  5 , and the spacer  14  is modified relative to the spacer  13  for the auxiliary contact  5 , the detail description will be give in blow. 
     The spacer  14  has a body portion  141  and a supporting portion  142  extending forwardly from a bottom of the body portion  141 . The body portion  141  includes a front end face  1411 , two side end faces  1412 , a top end face  1413 , and a rear end face  1415  opposite to the front end face  1411 . The spacer  14  further has a plurality of first contact retaining slots  14131  passing therethrough along an upper to bottom direction. The auxiliary contact  5  and a grounding contact  33 ′ are both received in the middle one of the first contact receiving slots  14131 . The spacer  14  is substantially same as the spacer  13  in the electrical connector  100 , except that the rear end face  1415 , different from the rear end face  1415 , defines an opening  1418 . The opening  1418  is throughout the body portion  141  and communicates with the middle one of the first contact receiving slots  14131 . The auxiliary contact  5  is located between the grounding contact  33 ′ and a rear wall  24 ′ of shell  2 . 
     The auxiliary contact  5  includes a flat portion  51  received in the middle one of the first contact receiving slots  14131 , a first spring tab  511  extending upwardly and rearward from an upper part of the flat portion  51  and a second spring tab  512  extending upwardly and forwardly from a lower part of the flat portion  51 . The first spring tab  511  and the second spring tab  512  are torn from the flat portion  51  and located respectively at a front and a rear of the flat portion  51 . The auxiliary contact  5  is assembled to the spacer  14  along an upper to bottom direction, and the first spring tab  511  passes through the opening  1418  backwardly and elastically contacts against the rear wall  24 ′ of the shell  2 ′. The second spring tab  512  elastically contacts against the first connecting  313 ′ of the grounding contact  33 ′. 
     Referring to  FIGS. 1-10 , the auxiliary contact  4  of the electrical connector  100  at least has one first shrapnel  411  contacting against the shell  2  and one second shrapnel  421  contacting against the grounding contact  33  so as to increase the contact points with the grounding contact  33  and the grounding paths to avoid electromagnetic interference (EMI) and reduce the signal cross talking. 
     It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. For example, the tongue portion is extended in its length or is arranged on a reverse side thereof opposite to the supporting side with other contacts but still holding the contacts with an arrangement indicated by the broad general meaning of the terms in which the appended claims are expressed.