Abstract:
An electrical connector includes a dielectric housing and a plurality of terminals mounted therein. A conductive ground blade is mounted in the housing and includes at least a pair of positioning arms projecting therefrom for engaging the metallic shields of a pair of coaxial cables. An independent cable management member is mounted on the housing and includes a partition extending between the positioning arms to separate the coaxial cables and maintain the metallic shields near the positioning arms.

Description:
FIELD OF THE INVENTION 
     This invention generally relates to the art of electrical connectors and, particularly, to a connector for a plurality of coaxial cables and including a system for terminating the metallic shields of high speed cables, such as the metallic braids of the cables. 
     BACKGROUND OF THE INVENTION 
     A typical high speed cable includes a center conductor or core surrounded by a tube-like inner dielectric. A shield is disposed outside the inner dielectric for shielding and/or grounding the cable. The shield typically is a tubular metallic braid. However, one or more longitudinal conductive wires have also been used and are commonly called “drain wires.” An insulating jacket surrounds the composite cable outside the shield. 
     Various types of connectors are used to terminate high speed cables. The connectors typically have contacts which are terminated to the center conductor or core of the cable. The connectors also have one form or another of a terminating member for terminating the metallic shield of the high speed cable, usually for grounding purposes. A typical system in such connectors may terminate the metallic shield to the terminating member by soldering or welding. Other systems use crimping procedures to crimp at least a portion of the terminating member securely to the metallic braid. 
     With the ever-increasing miniaturization of the electronics in various industries, such as in the computer and telecommunications industries, along with the accompanying miniaturization of electrical connectors, considerable problems have been encountered in terminating miniature high speed cables, particularly in terminating the metallic shield of the cable. For instance, the outside diameter of a small coaxial cable may be on the order of 0.090 inch. The outside diameter of the inner dielectric surrounding the conductor/core may be on the order of 0.051 inch, and the diameter of the center conductor/core may be on the order of 0.012 inch. Coaxial cables having even smaller dimensional parameters have been used. 
     The problems in terminating small coaxial cables often revolve around terminating the metallic shield of the cable. For instance, if soldering methods are used, applying heat (necessary for soldering) in direct proximity to the metallic shield can cause heat damages to the underlying inner dielectric and, in fact, substantially disintegrate or degrade the inner dielectric. If conventional crimp-type terminations are used, typical crimping forces often will crush or deform the inner dielectric surrounding the center conductor/core of the cable. In either case, damage or deformation of the inner dielectric will change the electrical characteristics of the cable. 
     The above problems are further complicated when the metallic shield of the high speed cable is not terminated to a cylindrical terminating member, but the shield is terminated to a flat terminating member or contact. For instance, an example of terminating the metallic shield or braid of a coaxial cable to a flat ground member is shown in U.S. Pat. No. 5,304,069, dated Apr. 19, 1994 and assigned to the assignee of the present invention. In that patent, the metallic braids of a plurality of coaxial cables are terminated to a ground plate of a high speed signal transmission terminal module. The conductors/cores of the coaxial cables are terminated to signal terminals of the module. Other examples are shown in U.S. Pat. No. 5,711,686, dated Jan. 27, 1998; U.S. Pat. No. 5,716,236, dated Feb. 10, 1998; U.S. Pat. No. 5,718,607, dated Feb. 17, 1998; U.S. Pat. No. 5,725,387, dated Marc. 10, 1998; and U.S. Pat. No. 5,785,555 dated Jul. 28, 1998, all of which are assigned to the assignee of the present invention. 
     The present invention is directed to further improvements in managing the termination of high speed coaxial cables, including the termination of the metallic shields of a plurality of cables to a terminating member, such as a ground blade. 
     SUMMARY OF THE INVENTION 
     An object, therefore, of the invention is to provide a new and improved electrical connector which includes a system for terminating the metallic shields of high speed cables. 
     In the exemplary embodiment of the invention, the connector includes a dielectric housing having a front mating face and a rear terminating face, a plurality of terminal-receiving passages extending generally between the faces, and a blade-receiveng passage extending generally between the faces. A plurality of terminals are received in the terminal-receiving passages. A conductive ground blade is received in the blade-receiveng passage. The ground blade includes at least a pair of positioning arms projecting from the ground blade at the rear terminating face of the housing for engaging the metallic shields of a pair of coaxial cables. An independent cable management member is mounted on the housing and includes a partition extending between the positioning arms to separate the coaxial cables and maintain the metallic shields near the positioning arms. 
     As disclosed herein, the ground blade is generally planar and includes a slot. The cable management member includes a wall portion projecting through the slot and between the positioning arms to provide an abutment shoulder to prevent the ground blade from backing out of the blade-receiving passage. The ground blade includes a pair of the positioning arms projecting from each opposite side thereof, with a partition on the cable management member extending between each pair of arms. This defines four quadrants for accommodating four coaxial cables. Four terminal-receiving passages are provided in the housing aligned with the four quadrants for receiving four signal terminals. 
     The invention also contemplates that a shield be disposed about at least a portion of the housing and engaging at least a portion of the cable management member to hold the member on the housing. The cable management member includes at least one locating projection disposed in a locating recess in the housing. The locating projection is on an arm of the cable management member, and the shield engages the arm to hold the cable management member on the housing. 
    
    
     Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which: 
     FIG. 1 is a front perspective view of an electrical connector embodying the concepts of the invention; 
     FIG. 2 is a rear perspective view of the connector; 
     FIG. 3 is a front perspective view of the ground blade of the connector; 
     FIG. 4 is a rear perspective view of the ground blade; 
     FIG. 5 is a rear perspective view of the cable management member; 
     FIG. 6 is a front perspective view of the connector, with the shield removed; 
     FIG. 7 is a rear perspective view similar to that of FIG. 6; 
     FIG. 8 is a rear perspective view taken at a different angle from that of FIG. 7; 
     FIG. 9 is a rear perspective view of only the housing and the ground blade; and 
     FIG. 10 is a rear perspective view of the housing, alone. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings in greater detail, and first to FIGS. 1-5, the invention is embodied in an electrical connector, generally designated  14 , which includes a dielectric housing, generally designated  15 , substantially surrounded by a front shield, generally designated  16 , and a back shield, generally designated  17 . The housing is a one-piece structure unitarily molded of dielectric material such as plastic or the like. Each shield  16  and  17  is a one-piece structure stamped and formed or drawn of conductive sheet metal material. 
     The connector is an input/output (I/O) electrical device wherein front shield  16  defines a front mating face  18  of the connector, and rear shield  17  defines a rear terminating face  20 . The front face actually is formed by a shroud  22  of shield  16  surrounding forwardly projecting contact portions of three rows of data transmission terminals, generally designated  24 . The data transmission terminals project through terminal-receiving passages  26  in the connector housing and have rear tail portions  25 . A conductive ground blade  28  projects through a blade-receiving passage  30  in the connector housing. A pair of high speed signal terminals  32  project through a pair of terminal-receiving passages  34  in the housing on each opposite side of ground blade  28 . Terminating or tail portions  36  (FIG. 2) of high speed signal terminals  32  project rearwardly of rear shield  17  on a rear platform  40  of the connector housing. 
     Only one of the high speed signal terminals  32  is shown in FIGS. 1 and 2, but it is understood that a pair of the high speed signal terminals are disposed on each opposite side of ground blade  28 . Similarly, only six data transmission terminals  24  are shown in FIG. 1, but thirty of such terminals may be arranged in three rows of passages  26  in the connector housing. 
     Front shield  16  has a pair of rearwardly projecting tabs  42  on both the top and bottom thereof. The tabs project rearwardly of a base plate  46  of the front shield through notches  47  in a base plate  48  of the rear shield. The top tabs are bent downwardly in the direction of arrows “A” (FIG.  2 ), and the bottom tabs are bent upwardly in the direction of arrow “B”. This secures the front and rear shields rigidly together about connector housing  15 . 
     Before proceeding with further details of the interior of the connector assembly, reference is made to FIGS. 3 and 4 which show details of conductive ground blade  28 . The blade is stamped and formed of sheet metal material. As can be seen, the blade is elongated and generally planar to define a long ground plate. Barbs  50  are stamped at opposite edges of the ground blade for establishing an interference fit within blade-receiving passage  30  of the housing. A pair of positioning arms  52  project from each opposite side of the ground blade at a rear terminating end  54  thereof. Each positioning arm includes a stamped window  56 . The positioning arms are arcuately shaped for engaging a metallic shield, such as metallic braids of coaxial cables. The positioning arms are soldered to the metallic shields, and windows  56  allow for the flow of solder material through the arms and into engagement with the shields. A slot  58  is formed in ground blade  28 . The slot is open at rear end  54  of the blade and has a closed end  58   a  which defines an abutment shoulder, for purposes described hereinafter. 
     FIG. 5 shows a cable management member, generally designated  60 , according to the invention. The cable management member includes a pair of oppositely extending partitions or walls  62  which extend between the upper and lower pairs of positioning arms  52  at the rear end of ground blade  28  as seen in FIGS. 1 and 2. The partitions have sloped entry surfaces  63  to guide the cables into position and catches  65  to retain the cables after they have been inserted therein. As such, partitions  62  and positioning arms  52  are effective to provide a cable management system which is divided into four quadrants for receiving four coaxial cables  64  (FIG. 2) terminated to tails  36  of the four high speed signal terminals  32  in the four passages  34  in the connector housing, as described above. In essence, the tails  36  of the four high speed signal terminals are aligned with the four quadrants defined by partitions  62  of cable management member  60  and positioning arms  52  of ground blade  28 . The cable management member has a pair of longitudinal flanges  66  on each opposite side thereof to define channels  68  for receiving the planar portions of the ground blade on opposite sides of slot  58  (FIGS.  3  and  4 ). A front abutment surface  70  (FIG. 5) of cable management member  60  abuts against the closed end  58   a  of slot  58  to prevent the ground blade from backing out of its passage in the connector housing. In other words, after the ground blade is inserted into the rear of housing  15 , assembly of cable management member  60  to the housing causes abutment shoulder  70  of the cable management member to engage abutment end  58   a  of slot  58  in the ground blade, whereby the cable management member is effective to prevent the ground blade from backing out of the housing. Still referring to FIG. 5, cable management member  60  is assembled to connector housing  15  by means of a pair of arms  72  having forwardly directed locating projections  74 . The locating projections are received in locating recesses in the connector housing, as described hereinafter. Alternatively, the ground blade  28  and the cable management member  60  may be preassembled, and then the ground blade/cable management member subassembly is installed onto the rear of housing  15 . 
     FIGS. 6-8 show the interior components of connector  14 , i.e. with front and rear shields  16  and  17 , respectively, removed. Arms  72  of cable management member  60  are located in slots  76  in a rear face  78  of housing  15 . It can be seen how partitions  62  of the cable management member cooperate with positioning arms  52  of ground blade  28  to provide a cable management system defining four quadrants between the partitions and the positioning arms. FIGS. 9 and 10 show that connector housing  15  includes a pair of locating recesses  80  above and below blade-receiving passage  30  for receiving locating projections  74  (FIG. 5) of cable management member  60 . The locating projections can be press-fit into locating recesses  80 , if desired, to provide a preliminary holding means for the cable management member. It should be understood that rear shield  17  abuts against the rear of arms  72  (FIG. 5) to hold the cable management member in its assembly position. Finally, FIGS. 9 and 10 show that platform  40  of the housing has notches  82  to facilitate the termination of discrete electrical wires to tail portions  25  of data transmission terminals  24 . 
     As is known in the art, a typical coaxial cable  64  (FIG. 2) has an inner conductor  84 , an inner dielectric  86  surrounding the inner conductor, a metallic shield or braid  88  surrounding the inner dielectric and an outer insulating jacket  90  surrounding the metallic shield. In terminating cable  64  to tail portion  36  of one of the high speed signal terminals  32 , and terminating metallic shield  88  of the conductor to arms  52  of ground blade  28 , outer jacket  90  of the cable is removed to expose a portion of metallic shield  88  at a location for engaging one of the positioning arms  52  and a portion of the inner dielectric  86  is removed to expose the inner conductor  84 . The shield is either cut or folded back to expose a distal end of inner conductor  84  for solder connection to tail portion  36  of one of the high speed terminals  32 . The cable is then positioned in the quadrant defined by the partition  62  and the positioning arm  52 . When so placed, the metallic braid of the coaxial cable is juxtaposed with the positioning arm  52  and can be easily soldered thereto with the window  56  allowing for the flow of solder material into engagement with the shield. In addition, the inner conductor is aligned such that it is in juxtaposition with the tail portion  36  of signal terminal  32  and can be easily soldered together. Although only one cable  64  is shown in FIG. 2, four such cables can be very easily terminated to ground blade  28  and terminal tails  36 , because partitions  62  of cable management member  60  cooperate with positioning arms  52  of the ground blade to divide the termination area of the cables into four quadrants for properly positioning the cables. 
     It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.