Patent Publication Number: US-6341986-B1

Title: Power cable assembly

Description:
FIELD OF THE INVENTION 
     The present invention relates to a power cable assembly, and particularly to a power cable assembly meeting SSI (Server System Infrastructure) standard requirements and which is easy to assemble. 
     BACKGROUND OF THE INVENTION 
     Applicant&#39;s copending application Ser. No. 09/196,859, which has been allowed, discloses a power cable assembly comprising an insulative housing, a plurality of power terminals received in the housing, and a cable having a plurality of conductive wires terminated to corresponding power terminals. An insulative cover for enclosing the conductive wires is further over-molded around the housing. However, over-molding an insulative cover over a housing is not suitable for mass production. Hence, an improved power cable assembly is required to simplify manufacture and reduce cost. 
     BRIEF SUMMARY OF THE INVENTION 
     A first object of the present invention is to provide a power cable assembly that is easy to manufacture and assemble, thereby reducing cost. 
     A second object of the present invention is to provide a power cable assembly having a pair of separate shells for improved shielding of the connector. 
     A power cable assembly in accordance with the present invention comprises an insulative housing, a plurality of terminals, a cable including a plurality of wires, each of which is terminated to a corresponding terminal, an EMI (Electrical Magnetic Interference) shield at a front end of the cable, a pre-molded rear cover, and an interlocking means separately formed on the housing, the EMI shield and the rear cover for interlocking the housing, the EMI shield and the rear cover together. 
     The housing comprises a block and a plurality of silos formed on a front face of the block. A passageway is defined through each silo which extends through the block. The terminals with the wires are securely received in the passageways of the silos of the housing. The pre-molded rear cover defines a cavity in a front face thereof for receiving the cable therein. 
     In a first embodiment of the present invention, the EMI shield is an integral shell. A ferrule at a rear end of the EMI shell fixedly clamps the cable. 
     The interlocking means comprises a rabbet groove at a rear end of the block of the housing, a front portion of the EMI shell, a pair of recesses defined in upper and lower faces of the block of the housing, and a pair of ribs being respectively formed on upper and lower inner faces of the cavity. The front portion of the EMI shell fittedly engages with the rabbet groove of the housing, and the ribs of the rear cover are correspondingly received in the recesses of the housing thereby securely assembling the housing, the EMI shell and the pre-molded rear cover together. 
     In a second embodiment of the present invention, the EMI shield comprises a front shell and a rear shell. The front shell comprises a flange formed at a front end thereof and an opening defined at a rear end thereof. The rear shell comprises a flange formed at a front end thereof and a ferrule at a rear end thereof. The rear shell passes through the front shell from the front to the rear of the front shell until the flange of the rear shell seats against a front face of a flange at the rear of the front shell, said flange defining a perimeter of the opening of the front shell. The ferrule of the rear shell fixedly clamps the cable. The interlocking means comprises two pairs of first ribs separately formed on four outer faces of the block of the housing, two pairs of tongues punched from four side walls of the front shell, two pairs of recesses defined by the tongues as the tongues extend away from the four side walls of the front shell, and two pairs of second ribs being respectively formed on four inner faces of the cavity of the rear cover. The block of the housing slides into the front shell with the first ribs thereof abut against the tongues of the front shell thereby securing the housing to the front shell of the EMI shield. The second ribs of the rear cover are correspondingly received in the recesses of the front shell and a front face of the rear cover abuts against the flange of the front shell thereby securely assembling the rear cover, the front shell and the housing together. 
     Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partly exploded view of a power cable assembly in accordance with a first embodiment of the present invention with a cable thereof being severed for clarify; 
     FIG. 2 is a perspective view of a housing of the power cable assembly shown in FIG. 1; 
     FIG. 3 is a partly assembled view of FIG. 1; 
     FIG. 4 is an assembled view of FIG. 1; 
     FIG. 5 is a cross-sectional view taken along line  5 — 5  of FIG. 4; 
     FIG. 6 is a partly exploded view of a power cable assembly in accordance with a second embodiment of the present invention with a cable thereof being severed for clarify; 
     FIG. 7 is a perspective view of a housing of the power cable assembly shown in FIG. 6, viewed from a different aspect; 
     FIG. 8 is a partly assembled view of FIG. 6; 
     FIG. 9 is an assembled view of FIG. 6; and 
     FIG. 10 is a cross-sectional view taken along line  10 — 10  of FIG.  9 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, a power cable assembly  100  in accordance with a first embodiment of the present invention comprises an insulative housing  10 , a plurality of conductive terminals  20 , a cable  30  comprising a plurality of wires  40  (only two shown for simplicity) each of which is terminated to a corresponding terminal  20 , a conductive shell  50  used as EMI (Electrical Magnetic Interference) shield surrounding the cable  30 , a pre-molded rear cover  60 , and an interlocking means being formed on the housing  10 , the EMI shell  50  and the rear cover  60  for securely assembling the housing  10 , the EMI shell  50  and the rear cover  60  together. 
     Also referring to FIG. 2, the housing  10  comprises a rectangular block  11  formed at a rear end thereof and a plurality of silos  14  arranged in rows and columns and formed at a front end of the block  11 , with a passageway  142  defined through each silo  14  and extending through the block  11 . The block  11  forms a flange  12  around the front end of the block  11 . The flange  12  defines a pair of through holes  126  at opposite ends thereof. Two outermost silos  14  in an upper row each form a key  144  on an upper face thereof for ensuring correct engagement of the silos  14  of the housing  10  with a corresponding structure of a complementary connector (not shown). 
     Each terminal  20  has the shape of a rectangular tube and comprises a pair of tabs  22  adjacent to a forward end thereof for securely engaging with inner walls (not labeled) of a corresponding passageway  142  of the housing  10 . A ferrule  26  at a rear end of each terminal  20  is used for clamping a jacket  44  of the wire  40  of the cable  30 , and a wing  24  between the tabs  22  and the ferrule  26  clamps and establishes an electrical connection with a conductor  42  of the wire  40  of the cable  30 . 
     The EMI shell  50  is rectangular in shape and comprises a ferrule  54  at a rear end thereof for firmly clamping the cable  30 . The cable  30  extends into the shell  50  from the rear end of the shell  50 . The wires  40  of a segment A of the cable  30 , together with the terminals  20  attached thereto, extend outside of the front portion  52  of the shell  50 . 
     The pre-molded rear cover  60  comprises a front face  61 , a cavity  62  defined in the front face  61 , and a boot  66  at a rear end thereof. A segment B of the cable  30  passes through the boot  66  and a segment C of the cable  30  extends into the cavity  62 . The boot  66  can prevent the segment B of the cable  30  from rotating and from moving forward and rearward. The pre-molded rear cover  60  further defines a pair of retaining holes  68  extending from a rear end to the front face  61  of the rear cover  60 . 
     The interlocking means in the first embodiment comprises a rabbet groove  114  at a rear end of the block  11  of the housing  10 , a front portion  52  at a forward end of the shell  50 , a pair of recesses  1   12  in upper and lower faces of the block  11  of the housing  10  and a pair of ribs  64  being respectively formed on an upper and a lower inner faces of the cavity  62 . 
     The power cable assembly  100  further comprises a pair of screws  70  for securely connecting the power cable assembly  100  to a complementary connector. 
     Referring to FIG. 3, in assembly, the terminals  20  are first inserted into corresponding passageways  142  of the housing  10  from the rear end of the block  11  and the tabs  22  of each terminal  20  are securely engaged with inner walls of each corresponding passageway  142 . 
     The front portion  52  of the shell  50  is fittedly engaged with the rabbet groove  114  of the block  11  of the housing  10 . The ferrule  54  of the shell  50  is clamped to the cable  30  to form a strain relief for preventing the segment A of the cable  30  from rotating and moving forward and rearward. 
     The pair of the screws  70  is inserted into the retaining holes  68  of the pre-molded rear cover  60 . 
     Referring to FIGS. 4 and 5, the block  11  of the housing  10  together with the shell  50  are then inserted into the cavity  62  of the pre-molded rear cover  60  with the pair of ribs  64  of the pre-molded rear cover  60  being correspondingly received in the pair of recesses  112  of the housing  10  thereby securely assembling the housing  10  with the shell  50  to the pre-molded rear cover  60 . At the same time, front ends of the pair of screws  70  extend through the through holes  126  of the housing  10  for engaging with the complementary connector. 
     Referring to FIGS. 6 and 7, in a second embodiment of the power cable assembly  100 ′ of the present invention, an insulative housing  10 ′ comprises block  11 ′ and a plurality of silos  14 ′ arranged in rows and columns and formed on a front face of the block  11 ′. 
     An EMI shield  50 ′ comprises a conductive front shell  52 ′ and a conductive rear shell  54 ′. The front shell  52 ′ comprises a flange  522 ′ formed at a front end thereof and has an opening  524 ′ defined at a rear end thereof. The flange  522 ′ defines a pair of through holes  5222 ′ at opposite sides thereof. The rear shell  54 ′ comprises a flange  542 ′ formed at a front end thereof and a ferrule  544 ′ at a rear end thereof. 
     The interlocking means in the second embodiment of the present invention comprises two pairs of first ribs  112 ′ separately formed on four outer faces of the block  11 ′ of the housing  10 ′, two pairs of tongues  526 ′ punched from four side walls  525 ′ of the front shell  52 ′, two pairs of recesses  528 ′ defined by the tongues  526 ′ as the tongues  526 ′ extend away from the four side walls of the front shell  52 ′, and two pairs of second ribs  64 ′ being respectively formed on four inner faces of the cavity  62 ′ of the rear cover  60 ′. 
     Referring to FIG. 8, in assembly, the rear shell  54 ′ is inserted into the front shell  52 ′ from a front side thereof and through the opening  524 ′ until a rear face of the flange  542 ′ is seated against a front face of a flange (not labeled) at the rear of the front shell, said flange defining the perimeter of the opening  524 ′. A cable  30 ′ is extended through the rear shell  54 ′ and the front shell  52 ′ via the ferrule  544 ′. The plurality of terminals  20 ′ attached to wires  40 ′ of the cable  30 ′ are then inserted and secured in the silos  14 ′ of the housing  10 ′. The housing  10 ′ is inserted into the front shell  52 ′ from the front end of the front shell  52 ′ until the first ribs  112 ′ of the block  11 ′ slide past and abut against the tongues  526 ′ of the front shell  52 ′. The ferrule  544 ′ of the rear shell  54 ′ is then fixedly clamped to the cable  30 ′. 
     Referring to FIGS. 9 and 10, the second ribs  64 ′ of the rear cover  60 ′ are correspondingly received in the recesses  528 ′ of the front shell  52 ′ and a front face  61 ′ of the rear cover  60 ′ abuts against the flange  522 ′ of the front shell  52 ′ thereby securely assembling the rear cover  60 ′, the front shell  52 ′ and the housing  10 ′ together. At the same time, front ends of the pair of screws  70 ′ extend through the through holes  5222 ′ of the front shell  52 ′ for engaging with the complementary connector. 
     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.