Patent Publication Number: US-6220895-B1

Title: Shielded electrical connector

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a shielded electrical connector, more particularly to an electrical connector with a shielding member that is capable of providing effective protection against electromagnetic interference. 
     Connectors are often used for signal transmission among the various electrical components in a computer. Referring to FIG. 1, a conventional electrical connector is shown to include a generally rectangular housing  10  made of an insulator material. The housing  10  has a front side formed with a receiving chamber  101  and a socket  102  formed in the receiving chamber  101 . The socket  102  has contact insert holes  103  for electrically and mechanically engaging a complementary electrical connector (not shown). A plurality of terminals  104  are disposed in the insert holes  103 , respectively, and have tips that extend downwardly from the bottom side of the housing  10  for electrical connection with a circuit board (not shown). The electrical connector further includes a shielding unit to prevent external electromagnetic waves from interfering and affecting signal quality during signal transmission. 
     The shielding unit includes first and second shielding components  20 ,  25  that cover the housing  10 . The first shielding component  20  includes top, rear, left and right wall portions  21 , and covers four sides of the housing  10  (excluding the front side and the bottom side). The bottom edge of the first shielding component  20  is formed with grounding legs  22  for grounding purposes. The second shielding component  25  has two sides formed with a respective thorn  251  for fixing the second shielding component  25  in a space formed between the inner wall surface of the receiving chamber  101  and the socket  102 . The bottom edge of the second shielding component  25  is also formed with a grounding leg  252  for grounding purposes. 
     It is noted that the protection against electromagnetic interference in the aforementioned conventional electrical connector is inadequate since no shielding effect is provided at the front side of the socket  102 . 
     FIG. 2 illustrates another conventional electrical connector with a shielding unit. As shown, the electrical connector includes a generally rectangular housing  10 ′ made of an insulator material. Like the housing  10  of the electrical connector of FIG. 1, the housing  10 ′ has a front side formed with a receiving chamber  101 ′, and a socket  102 ′ formed in the receiving chamber  101 ′. The socket  102 ′ has contact insert holes  103 ′ for engaging electrically and mechanically a complementary electrical connector (not shown). A plurality of terminals (not shown) are disposed in the insert holes  103 ′, respectively, and have tips that extend downwardly from the bottom side of the housing  10 ′ for electrical connection with a circuit board (not shown). The left and right sides of the housing  10 ′ are formed with a respective fastening recess  105 . The electrical connector further includes a shielding unit to prevent external electromagnetic waves from interfering and affecting signal quality during signal transmission. 
     The shielding unit is similar to that disclosed in U.S. Pat. No. 5,637,015 issued on Jun. 10, 1997 to Hon Hai Precision Ind. Co., Ltd., and includes first and second shielding components  30 ,  35  that cover the housing  10 ′. The first shielding component  30  includes a front wall portion  31  and left and right wall portions  32 . The front wall portion  31  is formed with a circular opening  311 , and a rearwardly extending guide piece  312  at the periphery of the opening  311 . The top edge of the front wall portion  31 , is bent rearward to form a press section  313 . Each of the left and right wall portions  31  has an engaging section  321  that is formed with a slit  3211 . The top edge of each of the left and right wall portions  32  is formed with a stepped section  322 . The bottom edge of each of the left and right wall portions  32  is formed with a downwardly extending grounding leg  323 . The second shielding component  35  includes a top wall portion  351  and a rear wall portion  352 . The rear wall portion  352  has forwardly projecting insert section  353  at left and right edges thereof. Each insert section  353  has a resilient piece  354  thereon. The front edge of the top wall portion  351  is formed with a stepped section  355 . The left and right edges of the top wall portion  351  are bent downwardly to form a respective press section  356 . 
     The first shielding component  30  is mounted on the housing  10 ′ at the front side of the latter so as to cover and be positioned on the front side and the left and right sides of the housing  10 ′. The second shielding component  35  is mounted on the housing  10 ′ at the rear side of the same so as to cover and be positioned on the top and rear sides of the housing  10 ′. 
     The front wall portion  31  of the first shielding component  30  provides the electrical connector of FIG. 2 with stronger protection against electromagnetic interference than that in the electrical connector of FIG.  1 . However, the electrical connector of FIG. 2 still has an unsatisfactory design due to the following reasons: From the manufacturer&#39;s viewpoint, there is a need to form two separate components; i.e., the first shielding component  30  with the front wall portion and the left and right wall portions, and the second shielding component  35  with the top and rear wall portions. During the manufacturing stage, the two components undergo separate processing operations. Particularly, two dies must be prepared when forming the two components. For each mold, the precision of the corners in the other mold must be taken into consideration. Furthermore, the corresponding angles of the press sections  313 ,  356  and the stepped sections  322 ,  355  that project from the edges of the two shielding components must be precisely matched. The high quality requirement during the die forming and production stages is troublesome and results in increased costs. In addition, because the two shielding components are mounted on the housing one after the other, and because the shapes of the shielding components have been set beforehand, extreme care must be undertaken when bending the different portions of the shielding components during the mounting of the same so as to avoid any deviation which can hinder precise mounting of the shielding components on the housing. This increases the difficulty in mounting the shielding components on the housing. Moreover, clearances between the shielding components cannot be entirely avoided when the shielding components are mounted on the housing. These clearances can have an adverse effect on the protection against electromagnetic interference. 
     SUMMARY OF THE INVENTION 
     Therefore, the main object of the present invention is to provide an electrical connector with a shielding member that is relatively convenient to assemble and that is capable of providing effective protection against electromagnetic interference. 
     Another object of the present invention is to provide an electrical connector with a shielding member that is relatively convenient to fabricate. 
     Accordingly, the shielded electrical connector of this invention electrical connector comprises a conductive shield including two side wall portions, a top wall portion and a front wall portion. The front wall portion has insert aperture for receiving a mating connector. The shield receives an insulative housing having a top side, a bottom side and a contact mounting member disposed in the shield to be accessible through the insert aperture in the front wall portion of the shield. Contacts are mounted in the housing with a mating portion disposed in the contact mounting member for engaging contacts of the mating connector. A conductive latch is unitarily supported by one of the side wall portions and extends along the contact mounting member for contacting a shield of the mating connector. 
     The housing of the shielded electrical connector preferably includes side walls extending from the top side to the bottom side. The side walls of the housing are disposed inwardly of the side wall portions of the shield. One of the side walls includes a notch for receiving the conductive latch. The two side wall portions and the front wall portion preferably unitarily depend from the top wall portion of the shield. The shield also preferably includes a rear wall portion unitarily depending from the top wall portion. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which: 
     FIG. 1 is an exploded view of a conventional shielded electrical connector; 
     FIG. 2 is an exploded view of another conventional shielded electrical connector; 
     FIG. 3 is a perspective view of the preferred embodiment of a shielded electrical connector according to the present invention; 
     FIG. 4 is an exploded view of the preferred embodiment with terminal:; removed; 
     FIG. 5 is a perspective, partly cut away view of the preferred embodiment with terminals removed; and 
     FIG. 6 is a plan view of the blank of the metal shield for fabricating the shielded electrical connection. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 3,  4  and  5 , the preferred embodiment of a shielded electrical connector according to the present invention is shown to comprise a housing  40  and a one-piece integrally formed shielding member  50 . Contacts  60 ,  62  are mounted on the housing as shown in FIG.  3 . The contacts  60 ,  62  are removed in FIGS. 4 and 5 for illustrative purposes. 
     The housing  40  is formed as a generally rectangular unitary hollow block made of an insulator material, and has a top side  41 , a rear side  42 , a bottom side  43 , left and right sides  44  and a front side  47 . The housing  40  further has a contact mounting member  45  formed therein and accessible via the front side of the housing  40 . The contact mounting member  45  is adapted for mating with a complementary electrical connector (not shown) in a conventional manner. In the present embodiment, the left and right sides  44  of the housing  40  are formed with left and right latching notches  461  adjacent to the front side, and left and right recesses  462  adjacent to the rear side  42 . The bottom side  43  has left and right ramps  463  obtusely angled with respect to the bottom side  43  to define a corner  4631  with a respective side  44 . The bottom side  43  of the housing  40  is formed with a T-shaped standoff  431  and a recessed rear edge  432  between the rear end of the ramps  463  and the rear standoffs  433 . The T-shaped standoff  431  has a crossbar  4311  defining a rearward surface  4312 . The rear standoffs,  433  define a forward surface  4331 . 
     The shielding member  50  is made by stamping and forming a conductive metal blank, as discussed in detail subsequently, and is mounted on the housing  40  to provide protection against electromagnetic interference. The shielding member  50  includes a top wall portion  52 , a front wall portion  51 , a rear wall portion  53 , and left and right wall portions  54  disposed adjacent to the top side  41 , the front side  47 , the rear side  42  and the left and right sides  44  of the housing  40 , respectively. The front wall portion  51  is formed with an insert aperture  511  for exposing the contact mounting member  45 . Left and right flanges  512  are connected respectively to the left and right edges of the front wall portion  51 . Two apertures  513  are formed in each of the left and right flanges  512 . The left and right flanges  512  are folded toward the front edge part of a respective one of the left and right wall portions  54 . Two protrusions  541  are formed on the front edge part of each of the left and right wall portions  54  to engage the apertures  513  on the left and right flanges  512 . The protrusions  541  and the left and right flanges  512  constitute a first retaining device for engaging the left and right edges of the front wall portion  51  with the front edge parts of the left and right wall portions  54 . 
     Each of the front wall portions  51  and the left and right wall portions  54  has a bottom edge formed with at least one fastening strip  551 . In this embodiment, the front wall portion  51  has two fastening strips  551  that extend from the left and right flanges  512 . The fastening strips  551  are folded toward the bottom side  43  of the housing  40  such that the fastening strips  551  abut firmly against the corner  4631  on the bottom side  43  at the ramps  463 . The ramps  463  are inclined to allow the strips  551  to be overformed. 
     Left and right resilient latch strips  522  are disposed on inner wall surfaces of the left and right wall portions  54 , and are connected unitarily to the front edges of the left and right wall portions  54 , respectively. The left and right latching notches  461  define a space that receives the left and right resilient latch strips  522 , respectively. The left and right resilient latch strips  522  are conductive for grounding to a shield of a mating connector (not shown) and catching behind a boss on a mating connector to latch a mating connector into a mating engagement (not shown). Left and right inward protrusions  553  are further formed on the inner wall surfaces at rear edges of the left and right wall portions  54 , respectively. The left and right recesses  462  in the housing engage the left and right protrusions  553 , respectively. The latch strips  522 , the protrusions  553 , that latching notches  461  and the recesses  462  cooperatively form a second retaining device for engaging the left and right wall portions  54  of the shielding member with the left and right sides  44  of the housing  40 . 
     Rear flanges  56  are connected respectively to the rear edges of the left and right wall portions  54  and are folded toward the left and right edges of the rear wall portion  53 , respectively. The rear flanges  56  serve as a third retaining device. Lower portions of the left and right edges of the rear wall portion  53  engage inwardly turned edges of rear flanges  56  of the left and right wall portions  54 . Upper portions of the rear wall portion  53  are formed with restraining strips  531  that are bent forwardly and outwardly in front of the respective rear flange  56 . The restraining strips  531  prevent flanges  56  from moving excessively forwardly. The bottom edge of each of the left and right wall portions  54  is further formed with a downwardly extending mounting leg  57  for mounting on a circuit board (not shown). 
     The electrical connector is made by stamping a metal blank  59  to form the shield  50  from a metal sheet. As shown in FIG. 6, the blank  59  defines the front wall portion  51  with the opening  511  therein and the two flanges  512  with apertures  513  and forward fastening strips  551 . The blank  59  also defines two opposing side wall portions  54  each with the latch strip  522  extending from a front edge, the rearward fastening strip  551  and the mounting leg  57  extending from a lower edge of each wall portion  54  and rear flanges  56 . The blank further defines a rear wall portion  53  with retaining strips  531  extending from side edges of the rear wall portion  53 . The front wall portion  51 , the side wall portions  54  and the rear wall portion  53  all radially extend from the top wall portion  52 . 
     The retention strips  531  are bent forwardly and outwardly from the outer edges of the rear wall portion  53 . The mounting legs  57  are bent into the final configuration. Indentations  553  and protrusions  541  are stamped into the side wall portions  54 . The latching strips  522  are folded back to oppose an inner surface of the respective side wall portion  54 . The front wall portion  51  and the opposing side wall portions  54  are orthogonally folded with respect to said top wall portion  52 . The flanges  512  are folded over the side wall portions  54 , and the apertures  513  receive protrusions  541 . The rear wall portion  53  is folded downwardly and the rear flanges  56  are folded inwardly to engage restraining strips  531 . 
     To complete the assembly, the contact  60 ,  62  are loaded into the housing  40 , and the housing  40  is inserted into the shield  50 . The latching strips  522  are received in notches  461  and indentations  553  are received into recesses  462 . The fastening strips  551  are bent under and around corners  4631  and against ramps  463  and bottom wall  43 . 
     After assembly referring to FIGS. 3-5, the rear flanges  56  engage the left and right edges of the rear wall portion  53 , and the shielding member  50  is capped on the housing  40  such that the top wall portion  52 , the front wall portion  51 , the rear wall portion  53 , and the left and right wall portions  54  are closely adjacent to the top side  41 , the front side  47 , the rear side  42  and the left and right sides  44  of the housing  40 , respectively. The left and right latching notches  461  receive and engage the left and right resilient latch strips  522 , while the left and right recesses  462  receive and engage the left and right protrusions  553 . The left and right recesses  462  have upper ledges  4621  that engage lower edges of the left and right protrusions  553  to limit upward movement of the housing  40  in the shield  50 . The protrusions  541  on the left and right wall portions  54  are engaged with the apertures  513  on the left and right flanges  512 . The contact mounting member  45  is accessible via the insert hole  511  in the front wall portion. Finally, the fastening strips  551  on the left and right flanges  512  and the left and right wall portions  54  are overfolded toward the bottom side  43  around the corner  4631  of the housing  40  such that the fastening strip  551  abuts firmly against the respective ramp  463  and the bottom side  43 . Front edges of forward fastening strips  551  abut against rear surface  4312  of T-shaped standoff  431  to restrain forward movement of the shield  50  with respect to the housing  40 . Front edges of rearward fastening strips  551  abut against recessed rear edge  432  also to restrain forward moment of the shield  50  with respect to the housing  40 . Rear edges of rearward fastening strips  551  abut against forward surface  4331  of rear standoffs  433  to restrain rearward moment of the shield  50  with respect to the housing  40 . The shielding member  50  is, thus, mounted closely and securely on the housing  40  to provide effective protection against electromagnetic interference. 
     In the shielded electrical connector of the present invention, the shielding member  50  is formed in a single punching operation, and can be mounted on the housing  40  by capping on the latter. The various retaining devices of the electrical connector ensure that the shielding member  50  is mounted closely and securely on the housing  40  so as to result in effective protection of contacts  60 ,  62  against electromagnetic interference. The shielding member  50  is relatively easy to assemble, and the die forming and production operations for the same are convenient to conduct, thereby resulting in reduced costs. 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.