Abstract:
A cable end connector includes a dielectric housing ( 10 ), a terminal ( 30 ) received in the housing, a shell ( 50 ) shielding the housing, and a retainer ( 60 ) attached to the shell for holding a coaxial cable ( 70 ) therein. The shell has a pair of arms ( 513 ) for accommodating a tail portion ( 31 ) of the terminal therebetween. A sealing tab ( 5133 ) extends from an end of each arm and encloses an end of the coaxial cable, and cooperates with the retainer to provide a complete Electro Magnetic Interference (EMI).

Description:
FIELD OF THE INVENTION 
     The present invention relates to a connector, and more particular to a cable end connector having a complete Electro Magnetic Interference (EMI) shielding. 
     BACKGROUND OF THE INVENTION 
     A cable end connector is often used for connecting a cable with an electronic device for transmitting Radio-frequency (RF) signal. A conventional cable end connector is, for example, disclosed in U.S. Pat. No. 5,263,877. The cable end connector includes a dielectric member holding a central terminal within an outer conductive shell. The central terminal has a U-shaped connection portion for connecting with a coaxial cable and a coupling portion for mating with a complementary plug. As disclosed in this patent, in assembly, an upper side wall of the dielectric member and a holder portion of the outer shell are bent substantially at a right-angle to hold the connection portion of the terminal and an inner conductor of the coaxial cable within the dielectric member and to crimp the coaxial cable braiding to the connector outer shell. 
     However, the holder portion has a pair of first wing portions bent around the dielectric member, and a pair of second wing portions bent around a braiding layer of the coaxial cable. A gap between the first and the second wing portions results in an incomplete shielding, whereby a failure in signal transmission would likely occur. 
     Hence, an improved connector for providing a complete Electro Magnetic Interference (EMI) shielding is required to overcome the disadvantage of the prior art. 
     The copending application Ser. No. 09/709,226 filed Nov. 8, 2000 with the same inventor and the same assignee, discloses an approach to replace the design of U.S. Pat. No. 5,263,877, and the instant application specifically focuses on the complete EMI shielding issue thereof. 
     BRIEF SUMMARY OF THE INVENTION 
     A main object of the present invention is to provide a cable end connector reliably shielding against Electro Magnetic Interference (EMI). 
     A cable end connector according to the present invention comprises a dielectric housing, a terminal received in the housing, a unitarily formed shell, and a retainer attached to the shell for holding a coaxial cable therein. 
     The housing includes a base portion and a tubular portion engaged with the base portion. The tubular portion axially defines a passageway therethrough. The terminal has a mating portion and a tail portion perpendicular to each other. The mating portion extends into the passageway for mating with a complementary connector. The tail portion is retained on the base portion for connecting with an inner conductor of the coaxial cable. The shell comprises a planar portion supporting the housing, and a trunk portion bendably connected to the planar portion and enclosing the tubular portion of the housing. A pair of arms rearwardly extend from the trunk portion. Each arm has a straight portion connecting with the tubular portion, a sealing tab and a bending portion protruding inwardly and connecting the straight portion with the sealing tab. The arms and a portion of the retainer define a space for accommodating the tail portion of the terminal. The retainer has a braiding crimp at an end thereof extending rearwardly beyond the arms of the trunk portion for grounding a braiding layer of the coaxial cable. Each sealing tab is located in the retainer, sealing a gap between a locking tab of the retainer and the braiding crimp. By this arrangement, the Electro Magnetic Interference (EMI) shielding is complete. 
     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 
     FIG. 1 is a perspective view of a terminal assembled within a housing of a cable end connector according to the present invention. 
     FIG. 2 is a perspective view of a tubular portion of a housing of the cable end connector. 
     FIG. 3 is a perspective view of a base portion of the housing. 
     FIG. 4 is a perspective view of a shell of the cable end connector, showing a trunk portion in a state before it is bent toward a planar portion thereof. 
     FIG. 5 is a perspective view of an unbentretainer of the cable end connector. 
     FIG. 6 is a perspective view of a cable end connector of the present invention assembled with an end portion of a cable without a retainer. 
     FIG. 7 is a view similar to FIG. 6 but with a retainer crimped around a part of the cable end connector. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings and particularly to FIGS. 1,  4  and  5 , a cable end connector in accordance with the present invention comprises a dielectric housing  10 , a terminal  30 , a metallic shell  50  shielding the housing  10  and the terminal  30 , and a retainer  60  for securing an end portion of a coaxial cable  70 . 
     Referring to FIG. 1, the dielectric housing  10  comprises a tubular portion  20  and a base portion  40  for engaging with the tubular portion  20 . Particularly referring to FIG. 2, a substantially rectangular passageway  21  is axially defined through the tubular portion  20 . Preferably, the tubular portion  20  forms a step  25  around an outer periphery thereof for supporting the shell  50 . Three recesses  22  are angularly defined in the step  25 . Three mounting legs  23  angularly depend from a bottom of the tubular portion  20  for locking with the base portion  40 . 
     Particularly referring to FIG. 3, the base portion  40  comprises an engaging block  43  and a flat portion  41  extending rearwardly from the engaging block  43 . A pair of retaining walls  45  project along the opposite sides of the flat portion  41  and a pair of projecting wings  42  adjacent the retaining walls  45  protrude respectively and horizontally from the opposite sides of the flat portion  41 . A pair of grooves  453  are respectively defined in an inward lower corner of each retaining wall  45  opposing each other. Three recesses  431  are angularly distributed in an outer periphery of the engaging block  43  and dimensioned for retaining the mounting legs  23 . 
     Referring to FIG. 1, the terminal  30  includes a mating portion  33  and a planar tail portion  31  substantially perpendicular to each other. The mating portion  33  is bifurcated and consists of a pair of beams  331  substantially projecting toward each other for mating with a complementary connector (not shown). 
     The shell  50  is unitarily formed and comprises a cylindrical trunk portion  51  and a planar portion  53  connected to the trunk portion  51 . FIG. 4 shows the shell  50  when the trunk portion  51  is unbent and is approximately perpendicular to the planar portion  53 . 
     The trunk portion  51  has a pair of arms  513  rearwardly extending from a lower portion thereof. Each arm  513  has a straight portion  5131 , a transition portion  5132  inwardly and rearwardly extending from the straight portion  5131 , and a sealing tab  5133  rearwardly extending from the transition portion  5132 . A recess  5134  is downwardly defined in a lower portion of the straight portion  5131 . The trunk portion  51  defines a hollow portion  515  therethrough for enclosing the tubular portion  20  of the housing  10 . Preferably, a step  514  is formed on an inner periphery of the trunk portion  51  for cooperating with the step  25  of the housing  10 . Three hooks  511  inwardly protrude on the hollow portion  515  for engaging with the three recesses  22  of the housing  10 . 
     The planar portion  53  has a front portion  531  for supporting the trunk portion  51 , and a rear portion  533  rearwardly extending from the front portion  531  for supporting the arms  513  and the housing  10 . The front portion  531  forms a pair of side walls  537  on opposite sides thereof for interferentially fitting with the outer periphery of the trunk portion  51 . A pair of recesses  535  are respectively defined in opposite sides of the rear portion  533 . 
     With reference to FIGS. 5 and 7, the retainer  60  is conductive and comprises a planar top wall  61 , a braiding crimp  65  rearwardly extending from an edge of the top wall  61  for grounding a braiding layer  73  of the coaxial cable  70  (see FIG.  6 ), and a strain relief  69  rearwardly extending from the braiding crimp  65  for securely clamping the coaxial cable  70 . A pair of locking tabs  63  respectively depend downwardly from opposite sides of the top wall  61  for engaging with the recesses  535  of the planar portion  53 . 
     Particularly referring to FIG. 6, the coaxial cable  70  includes an inner conductor  71 , a braiding layer  73 , an inner insulator  72  separating the inner conductor  71  and the braiding layer  73 , and an outer insulator  74  surrounding the braiding layer  73 . 
     Referring to FIGS. 6 and 7, a cable end connector assembly is assembled as follows. 
     (1) The tail portion  31  of the terminal  30  is inserted from the flat portion  41  of the base portion  40  of the housing  10 , with both sides (not labeled) thereof retained in the grooves  453 . 
     (2) The tubular portion  20  of the housing  10  is mounted onto the base portion  40 . The mating portion  33  of the terminal  30  extends into the passageway  21  of the tubular portion  20 , the beams  331  of the mating portion  33  abutting against corresponding inner walls (not labeled) of the passageway  21 . 
     (3) An inner conductor  71  of the coaxial cable  70  is soldered onto the tail portion  31  of the terminal  30 . 
     (4) The trunk portion  51  of the shell  50  is brought to encircle the tubular portion  20  of the housing  10 . The arms  513  accommodate the flat portion  41  of the housing  10  therebetween. 
     (5) The planar portion  53  is bent toward the trunk portion  51  until the planar portion  53  completely abuts a bottom of the housing  10 . 
     (6) The locking tabs  63  of the retainer  60  engage with the corresponding recesses  535  of the planar portion  53 , thereby fixedly retaining the arms  513  to an upper face of the planar portion  53 . The tail portion  31  of the terminal  30  is therefore surrounded by both the arms  513  and the top wall  61  of the retainer  60  but without contacting either. The braiding crimp  65  of the retainer extends beyond the straight portions  5131  of the arms  513  for securely clamping the braiding layer  3  of the coaxial cable  70  by clamping the sealing tabs  5133 . The outer insulator  74  of the coaxial cable  70  is firmly retained in the strain relief  69  of the retainer  60 . 
     Particularly referring to FIG. 7, the sealing tabs  5133  extending in the retainer  60  seal a gap defined between the braiding crimp  65  and the locking tabs  63  and connect the braiding layer  73  with the retainer  60 . By this arrangement, a complete and reliable Electro Magnetic Interference (EMI) shielding is obtained in this design. 
     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.