Abstract:
A cable end connector includes an insulative housing ( 10 ), a terminal ( 40 ) received in the housing, a metal shell ( 50 ) enclosing the housing, and an independent thin layer insulator ( 1 ). The independent thin layer insulator is located between the housing and the metal shell for insulating the terminal from the metal shell, whereby the cable end connector achieves a good insulation function between the terminal and the metal shell.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application is a continuation-in-part of a co-pending U.S. patent application entitled “LOW PROFILE CABLE END CONNECTOR”, with application Ser. No. 10/118,223, filed on Apr. 5, 2002, invented by the same inventor, and assigned to the same assignee of the present invention. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to a connector, and more particularly to a low profile cable end connector for high frequency application.  
           [0004]    2. Description of the Prior Art  
           [0005]    Cable end connectors are often used for transmitting Radio-frequency (RF) signals. The cable end connector normally has a terminal received in a housing thereof to mate with a complementary connector, such as a header. Such a conventional cable end connector is, for example, disclosed in U.S. Pat. No. 5,322,453. The cable end connector includes a dielectric member holding a central terminal within an outer conductive shell. The dielectric member is substantially cylindrical and defines a coaxial passageway therein for receiving the terminal. A pair of small tabs projects from the terminal and abuts against an inner surface of the dielectric member, thereby retaining the terminal in the dielectric member. The outer conductive shell is bent at right angle to cover an opening of the passageway. However, because current cable end connector is very small, the tabs of the terminal of the small cable end connector are too tiny to retain the terminal in the dielectric member. By a relatively large mating force of the header, the terminal tends to be pushed out of the dielectric member to touch the conductive shell, resulting in an unreliable insulation function between the terminal and the conductive shell.  
           [0006]    In order to solve the above-mentioned problem, U.S. Pat. No. 6,508,668 discloses a conventional cable end connector. The cable end connector also includes a dielectric member holding a central terminal within an outer conductive shell. As disclosed in this patent, in assembly, an upper cover section of the dielectric member and a holder portion of the outer shell are bent substantially at a right angle to hold the terminal and an inner conductor of the coaxial cable within the dielectric member and to crimp the coaxial cable braiding to the outer conductive shell.  
           [0007]    As for its design, the dielectric member must be formed of a flexible material to possess a certain degree of resiliency, thereby ensuring it capable of being bent to the right angle without breakage. On the contrary, however, the flexible dielectric member may be not strong enough to securely hold the terminal therein. The terminal, therefore, tends to move with respect to the flexible dielectric member when the cable end connector mates/unmates with/from the header. The movement inevitably bends the terminal of the cable end connector or a contact of the header.  
           [0008]    Hence, an improved cable end connector is desired to overcome the above-mentioned problems of existing cable end connector.  
         BRIEF SUMMARY OF THE INVENTION  
         [0009]    A main object of the present invention is to provide a cable end connector which is capable of reliably insulating a terminal from a metal shell thereof.  
           [0010]    Another object is to provide a cable end connector having a terminal reliably received in the housing thereof.  
           [0011]    A cable end connector according to the present invention comprises an insulative housing, a terminal received in the housing, a metal shell enclosing the housing, a circular thin layer insulator and a retainer attached to the shell for holding a coaxial cable therein. The insulative housing defines a passageway therethrough. The passageway has an end exposed to the metal shell. The terminal is received in the passageway of the housing for electrically engaging with a complementary connector. The metal shell comprises a planar portion covering the housing. The planar portion of metal shell faces the end of the passageway. The circular thin layer insulator is located between the end of the passageway of the housing and the planar portion of the metal shell, thereby insulating the terminal from the metal shell. The retainer is attached to the metal shell for retaining the metal shell to the housing.  
           [0012]    By such a design, the terminal is insulated from the metal shell by the covering of the circular thin layer insulator. When the terminal suffers from a large mating force of the header, the circular thin layer insulator prevents the terminal from touching the metal shell, thereby achieving a good insulation function. In addition, the cable end connector is capable of securely retaining the terminal therein.  
           [0013]    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. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is an exploded view of a cable end connector according to the present invention and a coaxial cable.  
         [0015]    [0015]FIG. 2 is an assembled view of FIG. 1.  
         [0016]    [0016]FIG. 3 is a partial assembled, upside-down view of FIG. 1.  
         [0017]    [0017]FIG. 4 is a perspective view of a metal shell of the cable end connector of FIG. 1.  
         [0018]    [0018]FIG. 5 is a perspective, upside-down view of a retainer of the cable end connector of FIG. 1.  
         [0019]    [0019]FIG. 6 is a cross-sectional view taken along a line  6 - 6  of FIG. 2. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    Referring to the drawings and particularly to FIGS. 1 and 2, a cable end connector in accordance with the present invention comprises a dielectric housing  10 , a terminal  40 , a metal shell  50  enclosing the housing  10  and the terminal  40 , a circular thin layer insulator  1  and a retainer  60  for securing an end portion of a coaxial cable  70  to the cable end connector.  
         [0021]    The dielectric housing  10  comprises a base portion  30  and a tubular portion  20 . The base portion  30  comprises a front circular portion  31  and a rear rectangular portion  32  extending rearwardly from the circular portion  31 . A pair of engaging blocks  33  protrude laterally from the circular portion  31  to abut against the shell  50 . A rearwardly exposed groove  34  is defined in a bottom of the base portion  30 . The tubular portion  20  axially and upwardly projects from the front circular portion  31 . A substantially rectangular passageway  21  is axially defined through the front circular portion  31  and the tubular portion  20 , and communicates with the groove  34 .  
         [0022]    The terminal  40  includes a bottom portion  41  and a pair of mating wings  43 . A pair of mating wings  43  extends upwardly from opposite lateral sides of the bottom portion  41  and projects toward each other for griping a mating of a complementary connector (not shown). A soldering tab  44  is bent downwardly from a rear side of the bottom portion  41 . A recess  441  is defined through the soldering tab  44 .  
         [0023]    Referring to FIG. 4, the shell  50  is unitarily formed of a metal sheet and comprises a substantially cylindrical trunk portion  51  and a substantially planar portion  53  connected to the trunk portion  51 . It should be noted that, before bending, the planar portion  53  is oriented vertically below the trunk portion  51 .  
         [0024]    The trunk portion  51  has a pair of arms  513  rearwardly extending from a lower portion thereof. Each arm  513  has an elongate distal end  512  protruding inwardly for accommodating the coaxial cable  70  therebetween. The trunk portion  51  defines a hollow portion  515  therethrough for receiving the tubular portion  20  of the housing  10 . Preferably, a pair of holding protrusions  514  (shown in FIG. 6) are formed in a lower portion of the trunk portion  51  for interferentially cooperating with the pair of engaging blocks  33  of the housing  10 .  
         [0025]    The planar portion  53  has a front portion  531  and a rear portion  533  rearwardly extending from the front portion  531  beyond the distal ends  512  of the arms  513  for supporting the arms  513  and the rectangular portion  32  of the housing  10 . The front portion  531  supports the trunk portion  51  of the shell  50  and the circular portion  31  of the housing  10 . A pair of side walls  537  project from on opposite sides of the front portion  531  for interferentially engaging with the outer periphery of the trunk portion  51 . A pair of cuts  535  are respectively defined in opposite sides of the rear portion  533 .  
         [0026]    In this preferred embodiment of the present invention, the circular thin layer insulator  1  is formed of a dielectric sheet. Alternatively, the circular thin layer insulator  1  can be formed of a dielectric material which is parasitically arranged on the front portion  531  of the metal shell  50 .  
         [0027]    With reference to FIGS. 1 and 5, the retainer  60  is conductive and comprises a planar top wall  61  and a strain relief  69  rearwardly extending from a rear edge of the top wall  61  for securely clamping the coaxial cable  70 . A contacting portion  62  is depressed from the top wall  61  and protrudes inwardly. A pair of locking tabs  63  respectively depend downwardly from opposite lateral sides of the top wall  61  for engaging with the cut  535  of the shell  50 .  
         [0028]    Particularly referring to FIG. 1, the coaxial cable  70  includes an inner conductor  71 , a conductive 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 .  
         [0029]    Referring to FIGS.  1 - 6 , the cable end connector of the present invention is assembled as follows.  
         [0030]    (1) The contacting wings  43  of the terminal  40  is inserted into the passageway  21  through the groove  34  of the housing  10 , abutting against corresponding inner walls (not labeled) of the passageway  21 . The soldering tab  44  of the terminal  40  is retained in the groove  34 .  
         [0031]    (2) The inner insulator  72  of the coaxial cable  70  is inserted in the groove  34 , and the inner conductor  71  extends forwardly through the recess  441  of the terminal  40  and is soldered to the soldering tab  44  and a lower surface of the bottom portion  41  of the terminal  40 .  
         [0032]    (3) The trunk portion  51  of the shell  50  encircles the tubular portion  20  of the housing  10  with the holding protrusions  514  abutting against the engaging blocks  33 . The arms  513  accommodate the rectangular portion  32  of the housing  10  therebetween.  
         [0033]    (4) The circular thin layer insulator  1  is positioned between the front circular portion  31  of the housing  10  and the planar portion  53  of the shell  50 .  
         [0034]    (4) The planar portion  53  of the shell  50 , which is originally oriented vertically downward, is now bent toward the trunk portion  51  until the planar portion  53  securely presses the circular thin layer insulator  1  to cover a lower opening of the passageway  2  defined in the bottom of the housing  10 .  
         [0035]    (5) The locking tabs  63  of the retainer  60  engage with the corresponding cuts  535  and abut against the bottom of the planar portion  53 , thereby fixedly retaining the arms  513  to an upper face of the planar portion  53 . The braiding layer  73  of the coaxial cable  70  is therefore surrounded by both the arms  513  and the top wall  61  of the retainer  60 . The shell  50  electrically connects with the braiding layer  73  by the arms  513  engaging with the braiding layer  73  and the retainer  60  electrically connects with the braiding layer  73  by the contacting portion  62  engaging with the braiding layer  73 , which makes the braiding layer  73  reliably grounded. The outer insulator  74  of the coaxial cable  70  is firmly retained in the strain relief  69  of the retainer  60 .  
         [0036]    By such a design, the terminal  40  and the inner conductor  71  are insulated from the shell  50  by the covering of the circular thin layer insulator  1 . When the terminal  40  suffers from a large mating force of the header, the circular thin layer insulator  1  prevents the terminal  40  and the inner conductor  71  of the coaxial cable  70  from touching the planar portion  53  of the shell  50 , thereby achieving a good insulation function. In addition, the thickness of the circular thin layer insulator  1  is also provided for matching the impedance of the cable end connector for a high frequency application. Furthermore, with the circular thin layer insulator  1 , the cable end connector has a low profile.  
         [0037]    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.