Abstract:
An electrical connector ( 1 ) comprises an insulative housing ( 3 ) with a front surface ( 302 ) and a rear surface ( 303 ) and a locker ( 4 ). The insulative housing defines a plurality of passageways ( 305 ) and channels ( 308 ). A plurality of contacts ( 6, 7 ) is secured in the passageways and channels. First, second and third projections ( 34, 36, 38 ) are configured in rows and parallel to the front and rear surfaces. The locker comprises an inner surface ( 44 ) being attached to the housing and a plurality of grooves ( 400, 402 ) depressed from the inner surface. Each groove defines a protrusion ( 404, 407 ). The protrusions are retained between the first and second rows of projections ( 34, 36 ) before the connector is mounted to a PCB ( 2 ), and moved to securely engage with the third row of projections ( 38 ) after the connector is mounted to the printed circuit board.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to the art of an electrical connector, and particularly to an electrical connector having a locker which can be moved to a position sandwiching a printed circuit board (PCB hereinafter) on which the electrical connector is mounted thereby more securely connecting the connector and the PCB together.  
           [0003]    2. Description of Related Art  
           [0004]    It is well known to provide a right angle connector mountable to a printed circuit board (hereinafter PCB), in which the connector has terminals perpendicularly engaging with respective electrical circuit traces of the PCB. The terminals may have right angle solder tails projecting from a housing of the connector and inserted into holes in the PCB, or right angle solder tails extending generally parallel to the PCB for surface mounting to circuit traces on the PCB. Such a connector has a problem that the electrical connections between the terminals and the circuit traces of the PCB often are subjected to external stresses, specially including rotating force which causes the connector to rotate about the PCB. Such a rotation may cause the electrical connections between the terminals and the PCB to break. To resolve this problem, U.S. Pat. No. 5,692,912 discloses the use of a tail-aligning device mountable on the housing to protect the solder tails of the terminals and to stabilize the connector.  
           [0005]    However, with the ever-increasing lower-profile trend of electrical connector, along with simplification in assembly of the connector, the tail-aligning device often is impractical and neither cost nor space effective, due to having a plenty of apertures for the terminals to extend through.  
           [0006]    Hence, an improvement to resolve the problems of the prior art is required.  
         SUMMARY OF THE INVENTION  
         [0007]    Accordingly, an object of the present invention is to provide an electrical connector which can be securely mounted to an edge of a PCB.  
           [0008]    Another object of the present invention is to provide an electrical connector which has improved signal transmission performance.  
           [0009]    In order to achieve the objects set forth, an electrical connector in accordance with the present invention comprises an insulative housing with a front surface and a rear surface thereby defining a mating direction from the front surface to the rear surface, and a locker. The insulative housing defines a contact-receiving passageways and channels extending in the mating direction. A plurality of contacts is secured in the contact-receiving passageways and channels. Projections are configured in three parallel rows on a bottom surface of the housing. The locker comprises an inner surface being attached to the housing and a plurality of grooves depressed from the inner surface. Each groove defines a protrusion to engage corresponding projections of the housing during mounting the connector to an edge of a PCB.  
           [0010]    Before the connector is mounted to the edge of the PCB, the protrusions of the locker are positioned between first and second rows of the projections of the connector. After the connector is mounted to the edge of the PCB, the locker is moved toward the rear surface of the insulative housing of the connector to reach a finally assembled position at which the protrusions slide over third row of the projections and fixedly engage therewith. At the finally assembled position, the locker sandwiches the edge of the PCB, whereby the connector and the edge of the PCB are more securely connected together and a possible rotation of the connector about the PCB is prevented.  
           [0011]    The contacts of the connector are divided into power contacts and signal contacts. The signal contacts include two differential pairs of signal contacts separated by three ground contacts whereby the problem of signal transmission skew/propagation problem can be effectively solved. One of the three ground contacts is located between the two pairs of signal contacts, and the other two are located respectively at two sides of the two pairs of signal contacts.  
           [0012]    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  
       [0013]    [0013]FIG. 1 is a bottom perspective view of an electrical connector in accordance with the present invention mounted to a printed circuit board;  
         [0014]    [0014]FIG. 2 is a top exploded view of the electrical connector;  
         [0015]    [0015]FIG. 3 is a bottom exploded view of the electrical connector;  
         [0016]    [0016]FIG. 4 is a front plan view of the electrical connector; 100151 FIG. 5 is a cross-sectional view of the electrical connector taken along line  5 - 5  of FIG. 4;  
         [0017]    [0017]FIG. 6 is a cross-sectional view of the electrical connector taken along line  6 - 6  of FIG. 5;  
         [0018]    [0018]FIG. 7 is a cross-sectional view of the electrical connector taken along line  7 - 7  of FIG. 5;  
         [0019]    [0019]FIG. 8 is a view similar to FIG. 4, but including a printed circuit board attached to the connector;  
         [0020]    [0020]FIG. 9 is a cross-sectional view taken along line  9 - 9  of FIG. 8; and  
         [0021]    [0021]FIG. 10 is a cross-sectional view taken along line  10 - 10  of FIG. 9. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]    Referring first to FIGS.  1 - 3 , an electrical connector  1  of the present invention is mounted to a PCB  2  of a hard disk (not shown) whereby information can be transmitted between the hard disk and another electronic device electrically connecting with the connector  1 . The connector  1  comprises an insulative housing  3 , a locker  4  surrounding the housing  3 , a plurality of power and signal contacts  6 ,  7  received in the insulative housing  10 , and a pair of latches  5 . The insulative housing  10  defines a base  30  having a front surface  302 , a rear surface  303  and a bottom surface  309 . The housing  3  further comprises two cavities  304  in the front surface  302  divided by a partition (not labeled) for receiving corresponding portions of a complementary connector (not shown), a plurality of passageways  305  exposed to the cavities  304 , and a plurality of channels  308  defined by numbers of interlayers (not labeled), each channel  308  extending rearwardly from a rear end of a corresponding passageway  305 , wherein the cavities  304 , passageways  305  and channels  308  communicate together to define a contact-receiving space. A passage  306  is defined between the two cavities  304 . A pair of leading arms  32  is defined at opposite sides of the housing  3  and extends in a mating direction (from the rear surface  303  to the front surface  302 ). Each leading arm  32  includes a tapered portion  320  beyond the front surface  302  and a rear portion  322  beyond the rear surface  303 . The rear portion  322  forms a slot  324 , and an engaging space  326  positioned at a side of the slot  324  and communicating with the slot  324 . Between each leading arm  32  and the base  30 , a first recess  300  and a second recess  301  are defined for retention of the locker  4 . A hollow portion  307  projects rearwardly from a middle of the base  30 , and a post  39  further extending downwardly from the hollow portion  307 . The post  39  has two parallel lateral surfaces  390 .  
         [0023]    The base  30  defines three rows of projections designated  34 ,  36  and  38  beyond the bottom surface  309 . In this embodiment, there are three first projections  34 , three pairs of second projections  36  and two third projections  38 . In addition, along the mating direction, each first projection  34  is arranged between a corresponding pair of second projections  36 , and the row of the third projections  38  is located between the rows of the first and second projections  34 ,  36 . Each projection  34 ,  36  and  38  has a vertical surface adjacent to the rear surface  303  for locking the locker  4  to the housing  3 , and an inclined surface adjacent to the front surface  302  for facilitating the locker  4  to slide over the projections  34 ,  36 ,  38  when the locker  4  is assembled to the housing  3 .  
         [0024]    The locker  4  comprises a main body  40  with front surface and rear surface, and a pair of retaining frames  42  respectively at lateral ends of the main body  40 . The main body  40  has an inner surface  44 , a plurality of first grooves  400  and second grooves  402  in the inner surface  44 . The second grooves  402  are wider than the first grooves  400 . First protrusions  404  and second protrusions  407  are respectively formed in the first and second grooves  400 ,  402 . Each first protrusion  404  forms a vertical surface  405  adjacent to the front surface  440  and an inclined surface  406  adjacent to the rear surface  442 . Each second protrusion  404  has the same structure as the first protrusion  404 , and includes a vertical surface  408  adjacent to the front surface  440  and an inclined surface  409  adjacent to the rear surface  442 . Each retaining frame has a first wall  420  and a second wall  422  parallel to each other thereby sandwiching the leading arm  32  of the housing  3  therebetween. Adjacent to middle of the main body  40 , a pair of fingers  46  extends rearward, while a rib  48  projects upwardly from the inner surface  44 .  
         [0025]    Each power contact  6  has a retention portion  60 , a contact portion  62  projecting forward from the retention portion  60 , and a tail portion  64  for mounting on the PCB  2 . The contact portion  62  further defines a curved front end portion  620  for engaging a complementary connector. The signal contacts  7  and the power contacts  6  have similar structure. Each signal contact  7  has a retention portion  70 , a contact portion  72  with an end portion  720 , and a tail portion  74  for mounting on the PCB  2 . Each latch  5  has a trunk  50  and a pair of legs  52  extending downwardly from a bottom side of a rear end of the trunk  50 . Two teeth  500  are formed on a top side of a front end of trunk  50  of each latch  5 . In addition, a laterally bent portion  502  is formed at the rear end of the trunk  50  of each latch  5 . Each leg  52  has a barb  520  for enhancing engagement with the PCB  2 .  
         [0026]    [0026]FIG. 4 illustrates how the locker  4 , the latches  5  and the contacts  6  and  7  are assembled to the housing  3  of the connector  1  of the present invention. With reference to FIGS.  5 - 7 , the locker  4  is assembled to the housing  3  from the front surface  302  to the rear surface  303 . The latches  5  and the contacts  6  and  7  are inserted into the housing  3  from the rear surface  303  to the front surface  302 . The contacts  6  and  7  are inserted into the channels  308  of the housing  3  until the contact portions  62  and  72  of the contacts  6  and  7  are located in the passageways  305 . The barbs of the retention portions  60 ,  70  of the contacts  6 ,  7  bite into the housing  3 , and the tail portions  64  and  74  are exposed beyond the rear surface  303  of the housing  3  for soldering to the PCB  2 . The latches  5  are inserted into corresponding slots  324  of the housing  3 . The teeth  500  bite into the housing  3 , and the bent portions  502  engage in the engaging spaces  326 , thereby to securely fix the latches  5  to the housing  3 . The leading arms  32  each engage a corresponding retaining frame  42 , and are surrounded by a corresponding first wall  420  or second wall  422  of the retaining frame  42 . The rib  48  is fitted in the passage  306 , whereby the post  39  is fitted in the pair of fingers  46 . In this way, the locker  4  is retained to the housing  3 .  
         [0027]    To ensure the locker  4  to be reliably retained to the housing  3 , the three rows of projections  34 ,  36  and  38  serve as retention means during different stages of attachment of the locker  4  to the housing  3 . As shown in FIGS.  5 - 7 , during the movement of the locker  4  in the mounting process, the vertical surface  408  of the second protrusions  407  first engages corresponding vertical surface of the second projections  36 , and the locker  4  therefore cannot separate from the housing  3  in a reverse direction (i.e., toward the front surface  302  of the housing  3 ). At the same time, the inclined surface of the first protrusions  404  locates on corresponding inclined surface of the third projections  38 . At this position, a rear face of the retaining walls  42  of the locker  4  is in line with the rear surface  303  of the base  30  so that the connector  1  together with the locker  4  can be mounted to an edge of the PCB  2  by having the post  30 , the legs  52  of the latches  4  and the tail portions  64 ,  74  of the contacts  6 ,  7  fitted into corresponding holes of the PCB  2 . The tail portions  64 ,  74  are then soldered to the PCB  2 . Referring back to FIG. 2, the signal contacts  7  consist of two differential pairs of signal contacts can be as short as possible so as to improve the problem signal skew/propagation delay.  
         [0028]    FIGS.  8 - 10  show the locker  4  having been completely moved the finally assembled position, along the mating direction to enforce the connection between the connector  1  and the PCB  2 . After the connector  1  is mounted to the PCB  2  and the locker  4  is located at the position of FIGS.  5 - 7 , the locker  4  is further moved rearwards on the connector  1  so that the inclined surface  406  of the first protrusions  404  slide over the inclined surface  38  and then the first projections  34  to reach the finally assembled position at which the vertical surface  408  of the second protrusions  407  engages with the vertical surface of the first projections  34 . At this position, also referring to FIGS. 1 and 3, the edge of the PCB  2  is sandwiched between the first and second walls  420 ,  422  of the locker  4  and between the hollow portion  307  of the housing  3  and the fingers  46  of the locker  4 , whereby the connector  1  and the PCB  2  are securely connected together, and a possible rotation of the connector relative to the PCB is prevented.  
         [0029]    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.