Abstract:
An electrical connector assembly includes a first electrical connector ( 10 ) having first contacts ( 13 ) provided therein and a second electrical connector ( 2 ) having second contacts provided therein. The first connector includes a metal cover ( 10 ) defining a locking hole ( 11 ) therein. The second connector has a metal shell ( 4 ) shielding the second connector. The shell includes a resilient spring arm ( 421 ) integrally attached thereto. The arm has a cam ( 422 ) raised inwardly therefrom and retainably received in the locking hole of the first connector.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a electrical connector which are mounted on a printed circuit board. In particular, the invention relates to a connector assembly which has a shielding means for EMI protection.  
         [0003]     2. Description of the Prior Art  
         [0004]     Conventional high speed connectors comprise a plug and a receptacle interconnected through contact fingers. Such connectors form a grounding means surrounding the adjoining surfaces of the receptacle and the plug in order to afford electromagnetic interference (EMI) shielding around the contact fingers. In conventional connectors, the grounding mechanism has a latching mechanism.  
         [0005]     An example of such a plug connector is disclosed in U.S. Pat. No. 5,660,558 issued to Osanai et al. on Aug. 26, 1997. The Osanai connector includes an insulator defining a pair of grooves, a shell held to the insulator, and a hood attached to the shell. The shell includes a shielding portion cover the insulator for EMI protection, and a pair of coupling portions formed integrally with the shielding portion. Each coupling portion includes a hook portion received in a corresponding groove of the insulator and engaging nails protruding beyond the groove. The hood includes an elastic portion on an upper portion o the shell. During insertion into a mating connector, exert a downward force on the elastic portion of the hood, the coupling portion of the shell is pressed downwardly, the engaging nails is pushed into the grooves and further received in locking holes of the mating connector, then the coupling portion is released and the engaging nails is further locked in the locking holes of the mating connector, and thus a secure connection is obtained.  
         [0006]     However, mating faces between the engaging nails and the locking holes are relative small and easy to be damaged after repeated insertion and withdraw with the mating connector. Moreover, this conventional connector needs enough space to press the elastic portion of the hood during engage and disengage with the mating connectors. Therefore, this latch means is inconvenient when used in relative small space, such as internal spaces of electronic appliances.  
         [0007]     Hence, an improved latch means of the mated electrical connectors is desired to overcome the foregoing shortcomings.  
       BRIEF SUMMARY OF THE INVENTION  
       [0008]     A main object of the present invention is to provide an electrical connector with a reliably latch means which is easy to be manufactured.  
         [0009]     Another object of the present invention is to provide an electrical connector assembly having an improved shell for Electro-Static-Discharge (ESD) which can assure an electrical interconnection therebetween.  
         [0010]     An electrical connector assembly includes a first electrical connector having first contacts provided therein and a second electrical connector having second contacts provided therein. The first connector includes a metal cover defining a locking hole therein. The second connector has a metal shell shielding the second connector. The shell includes a resilient spring arm integrally attached thereto. The arm has a cam raised inwardly therefrom and retainably received in the locking hole of the first connector.  
         [0011]     Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  is a perspective view of an electrical connector assembly according to the present invention;  
         [0013]      FIG. 2  is another perspective view of  FIG. 1 ;  
         [0014]      FIG. 3  is a perspective view of a plug connector of the electrical connector assembly;  
         [0015]      FIG. 4  is a perspective view of a receptacle connector of the electrical connector assembly;  
         [0016]      FIG. 5  is an exploded view of  FIG. 4 ;  
         [0017]      FIG. 6  is another exploded view of  FIG. 4  from a different aspect;  
         [0018]      FIG. 7  is a partially assembled view of  FIG. 6 , wherein a plurality of receptacle contacts and a cable assembly are assembled within a dielectric housing. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]     Referring to  FIGS. 1, 2  and  3 , an electrical connector assembly (not labeled) of the present invention mounted on a main printed circuit board (PCB, not shown) includes a plug connector  1  and a receptacle connector  2  mating with the plug  1 . The plug  1  includes a plug body  12 , a plurality of plug contacts  13  received in the plug body  12  and a metal cover  10  surrounding and shielding the plug body  12 . The cover  10  defines a pair of locking holes  11  in both sides therein.  
         [0020]     Referring to  FIGS. 4, 5  and  6 , the receptacle connector  2  includes a dielectric housing  3 , a shell  4 , a plurality of receptacle contacts  5  received in the housing  3  and a cable assembly  6  connecting with the receptacle contacts  5 .  
         [0021]     The housing  3  includes a mating portion  30  for mating with the plug  1  and two rows of receiving cavities  31  defined adjacent to the mating portion  30 . A pair of openings  32  are defined in an upper and lower surfaces of the housing  2  away from the mating portion  30 . A plurality of passages  33  are spaced apart and communicating with respective ones of the receiving cavities  31 . Each opening  32  has a keeper portion  34  extending inwardly from opposite sides therefrom. The housing  2  further has a pair of retention portions  35  projecting outwardly from both sides of the housing  2 .  
         [0022]     As best shown in  FIG. 6  in conjunction with  FIG. 5  and  7 , the shell  4  is stamped from one metal sheet and includes an upper plate  40 , bottom plate  41  and two side plates  42 . Each of the upper plate  40  and the bottom plate  41  has a plurality of grounding tabs  401 ,  411  extending inwardly therefrom. The upper plate  40  defines a pair of notches  402  in a front portion thereof, thereby forming a cantilever beam  43  between the notches  402 . The beam  43  has an arc shaped head portion  404  extending downwardly from a free end of the beam  43 . The head portion  404  acts as a lead-in surface and a clamp when the plug  1  is mated together. Each side plate  42  defines a retention hole  420  for engaging with the retention portion  35 . Each side plate  42  further includes a resilient spring arm  421  extending forwardly therefrom. Each arm  421  has a cam  422  raised inwardly and oppositely facing each other. Each cam  422  includes an engaging surface  424  and a convex guiding surface  425  immediately in front of the engaging surface  424 . The engaging surfaces  424  are substantially perpendicular to inner side surfaces of corresponding arms  421  and are oriented opposite to free ends of the arms  421 . The convex guiding surfaces  425  face toward free ends of the corresponding arms  421  and act as lead-in surfaces during the receptacle  2  mating with the plug  1 . Each arm  421  further includes a lead-in surfaces  423  extending outwardly from a free end thereof.  
         [0023]     Each receptacle contact  5  includes a contacting portion  51  for mating with the plug  1  and a tail portion  52  for connecting with the cable assembly  6 .  
         [0024]     The cable assembly  6  is of two rows and each includes a plurality of cables  61  and a ground bar  62  connecting with the cables  61 . The cables  61  are substantially micro coaxial cables and each includes a jacket insulator layer, a braid layer, an inner insulator layer and a center conductor (not shown). The structure and the function of the micro coaxial cable is well known to those skilled in the art, a detailed description is omitted herein. The ground bar  62  is soldered with the braid layers (not shown) of the cables  61 .  
         [0025]     Referring to  FIGS. 4 through 7 , in assembly, the contacting portions  51  of the receptacle contacts  5  are inserted into the housing  3  along respective ones of the passages  33  and spaced along the receiving cavities  31 . The cables  61  of the cable assembly  6  extend along the corresponding passages  33  thereafter, while the ground bars  62  are blocked by the keeper portions  34  respectively. The center conductors (not shown) of the cables  61  are soldered with respective ones of the tail portions  52  of the receptacle contacts  5 . Finally, the shell  4  substantially surrounds the housing  3 . The shell  4  covers the housing with the upper and the bottom plates  40 ,  41  along an upper and an bottom surfaces (not labeled) respectively, and the grounding tabs  401 ,  411  of the upper and bottom plates  40 ,  41  pressing the ground bars  62 , as such the retention portion  35  of the housing  3  are interference fitted in the retention holes  420  of the side plates  42 . The beam  403  and the arms  421  extend beyond the mating portion  30  of the housing  3  for mating with the plug  1 .  
         [0026]      FIGS. 1 and 2  show the plug  1  and the receptacle  2  in fully mated condition. During mating, a free end of the plug  1  is effective to engage the lead-in surfaces  423  of the arms  421  respectively, to gradually deflect the arms  421  outwardly and gradually increase the insertion forces until the plug contacts  13  engage with the receptacle contacts  5 , as such the plug  1  slides along the convex guiding surfaces  425  of the cams  422  of the receptacle  2 , thus the cams  433  are radially inwardly received in the locking holes  11  of the plug  1 , and the head portion  404  of the beam  403  abuts against a top surface of the cover  10 . It can be seen that when the mating complete, the engaging surfaces  424  of the cams  422  of the receptacle  2  latchably abuts against inner side surface of the locking holes  11  of the plug  1 . It is difficult for the engaging surface  424  to unmate form the inner side surface of the locking holes  11  and to slide out of the locking holes  11 . Therefore, the plug  1  and the receptacle  2  are reliably connected together.  
         [0027]     It should be noted that as the mating occurs, the arms  421  of the shell  4  of the receptacle  2  connect with the metal cover  10  of the plug  1  before the plug contacts  13  contact with the receptacle contacts  5 . Therefore, the static electronics deposited on the connectors are discharged prior to data transmitting and power current flowing between the plug  1  and the receptacle  2 .  
         [0028]     It is to be understood, however, that even though numerous, characteristics and advantages of the present invention have been set fourth in the foregoing description, together with details of the structure and function of the invention, the disclosed 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.