Abstract:
A connector for use in terminating communications cables including electrical contacts ( 42 ) arranged to receive wires ( 30 ) of a communications cable ( 60 ), at least one cover ( 12, 22 ) pivotally connected with the connector and having wire-receiving spaces ( 14, 24 ), wherein the cover is arranged to move pivotally to bring wires positioned in its wire-receiving spaces into engagement with the contacts ( 42 ).

Description:
TECHNICAL FIELD 
       [0001]    This invention relates to a connector for use in terminating communications cables. 
       SUMMARY OF THE INVENTION 
       [0002]    In a first aspect the present invention provides a connector for use in terminating communications cables including: electrical contacts arranged to receive wires of a communications cable; at least one cover pivotally associated with the connector; wire receiving spaces for guiding the wires are associated with the at least one cover; and the at least one cover is arranged to move pivotally to bring the wires into engagement with the electrical contacts. 
         [0003]    The electrical contacts will preferably be insulation-displacing or -piercing contacts, but other kinds of contacts may be used, for example when stripped wire ends are provided for connection to the contacts. The electrical contacts may be provided on a removable contact carrier, for example on opposed faces of the carrier, and the carrier may be retained in the connector by the at least one cover. The carrier may at least partly shield the inside of the connector from external electromagnetic radiation, and may at least partly prevent emission of electromagnetic radiation from the interior of the plug to the outside. Preferably the carrier will include cross-shaped or other internal shielding to prevent or reduce cross-talk radiation between respective wire pairs within the plug. The carrier may include at least one recess that aligns with the at least one cover to position the carrier in the connector. The recess may receive a cam portion of the at least one cover to position the carrier. 
         [0004]    The at least one cover may be pivotally moveable from a first position to a second position, the cable terminated by the connector has a longitudinal axis and in the first position the wire receiving spaces extend away from the longitudinal axis of the cable and in moving to the second position the wire receiving spaces are brought closer to aligning with the axis. The at least one cover may at least partly shield the inside of the connector from external electromagnetic radiation and may at least partly prevent or reduce emission of its internal electromagnetic radiation to the outside. The connector may be in the form of a plug or a jack, and may include two covers, which may be provided on opposite sides of the connector. 
         [0005]    The connector may include two (or more) shells which fit about the cable, the shells preferably including resilient flanges, which flanges press against the cable to grip the cable, and which flanges may establish electrical contact with foil, braid, or other electromagnetic shielding carried by the cable. The resilient flanges may be provided on a removable insert of the shell. The shells may be a snap-fit together, the snap-fit preferably being achieved by way of a lug which runs run for substantially the entire length of at least one of the shells. 
         [0006]    In preferred embodiments of the invention, at least one, more preferably all, of the resilient flanges is/are provided with teeth having sharp points that pass through the folded-back braid or foil shield of the cable and sink into the cable jacket, to both retain the connector on the cable and make electrical continuity between the cable shield and the connector. Designs having all of the flanges toothed to provide cable retention and electrical continuity are superior to designs in which one flange provides electrical continuity, and the rest of the flanges are untoothed continuous ridges that must grip the cable beyond the folded-back braid/foil shield in order to resist sliding along the cable jacket. The more preferred toothed flange design thus achieves better cable retention and simplifies installation since the length of the braid/foil shield that is folded back over the cable jacket is not critical, whereas for untoothed flange designs the folded-back shield length must be adjusted to be engaged by only the first electrical-continuity flange but not by the other cable-gripping flanges. 
         [0007]    A second aspect the present invention accordingly provides a cable clamp for a connector, the cable clamp including the aforementioned two or more shells which fit about a cable, wherein the shells further include resilient flanges which press against the cable to grip the cable and which may establish electrical contact with the usual shielding braid or foil of the cable. The resilient flanges may be provided on a removable insert of the shell. The cable clamp preferably includes two shells which snap-fit together fit about the cable. The snap-fit may be achieved by way of a lug which runs for substantially the entire length of at least one of the shells. 
         [0008]    In a third aspect the present invention provides a contact carrier for use with a connector including: electrical contacts for interengagement with wires of a communications cable are provided on a body portion of the carrier; the carrier includes at least one recess that may be engaged with the connector to retain the carrier in the connector when the carrier is correctly inserted in the connector. The carrier may at least partly shield the inside of the connector from external electromagnetic radiation, and may at least partly prevent emission of electromagnetic radiation from the interior of the plug to the outside. Preferably the carrier will include cross-shaped or other internal shielding to prevent or reduce cross-talk radiation between respective wire pairs within the plug. The electrical contacts may be provided on opposed faces of the carrier. 
         [0009]    The carrier and the cover or covers of the connector are preferably provided with snap-engageable formations, for example groove and recess formations, to retain the cover(s) in closed position about the carrier. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 
           [0011]      FIG. 1  is a perspective view of a first sub-assembly which forms part of an embodiment of a connector according to the present invention; 
           [0012]      FIG. 2  shows a second sub-assembly for use with the sub-assembly of  FIG. 1 ; 
           [0013]      FIGS. 3A to 3G  illustrate the snap-fitting together of the first and second sub-assemblies; 
           [0014]      FIG. 4  shows the first and second sub assemblies assembled together with a cable to be terminated; 
           [0015]      FIG. 4A  shows the assembly of  FIG. 3  with wire ends trimmed; 
           [0016]      FIG. 5 &amp; 6  show a thirdsub-assembly being fitted to the assembly of  FIG. 4 ; 
           [0017]      FIG. 7  shows an assembled connector according to the invention; 
           [0018]      FIGS. 8 &amp; 9  illustrate components of the connector of  FIG. 7  in more detail; 
           [0019]      FIG. 10  shows an alternative embodiment of a connector according to the invention partly assembled; 
           [0020]      FIGS. 11 and 12  show the connector of  FIG. 10  being further assembled; 
           [0021]      FIGS. 13 and 14  show the connector of  FIG. 10  fully assembled; 
           [0022]      FIG. 15  shows the preferred toothed spring flanges of the cable-enclosing half-shell sub-assemblies; and 
           [0023]      FIG. 16  shows the preferred snap-fit slot and rib formations for securing the hinged covers in the closed position on the contact carrier. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0024]    Referring to  FIG. 1  a first sub-assembly  10  of a connector is shown which includes a shell in the form of casing  11  and an electrically-conductive cover  12 , both of which are formed from a metallic alloy known in this field of technology as “Zamak”. Cover  12  is pivotally connected to casing  11  and may pivot about axis A. Wire-receiving spaces  14  are provided in a plastic lacing fixture  16  which is affixed to the inside of cover  12 . Referring to  FIG. 2 , a second sub-assembly  20  is shown which is complementary to the first sub-assembly and is similar in construction. Cover  22  and casing  21  are formed from Zamak and are pivotally connected about axis B. Wire-receiving spaces  24  are provided in lacing fixture  26 . Casing  21  is identical to casing  11 . 
         [0025]    The casings  11  and  21  both include removable inserts  13  which include resilient flanges  15 . The casings  11  and  21  are arranged to be snap-fitted together about a cable to be terminated to form a cable clamp around the cable. A foil-shielded cable is typically used. A length of outer insulation is removed from the end of the cable to be terminated and a section of the exposed foil shield is folded back over the cable outer insulation. The resilient flanges  15  become compressed about the cable when casings  11 ,  21  are snap-fitted together to grip the cable and provide strain relief. Inserts  13  are made of electrically conductive material and press against the folded back section of foil to achieve electrical continuity between the foil shield in the cable and the connector. Casing  11  includes a lug  17  and a recess  18 . Casing  21  includes complementary recess  28  and lug  27 . To snap-fit the casings together lug  17  is snap-fitted into recess  28  and lug  27  is snap-fitted into recess  18 . 
         [0026]    Referring to  FIGS. 3A to 3G , the operation of snap-fitting together the two casings is illustrated. In these figure the cable is not shown for simplicity. At  FIG. 3A , casings  11 ,  21  are brought together until they touch (see  FIG. 3B ). Casings are then manipulated so that lugs  17 ,  27  align with recesses  18 ,  28  (see  FIG. 3C ). At  FIG. 3D , casings are aligned so that recesses  81 ,  71  line up with lugs  80 ,  70  which are visible in  FIGS. 1 and 2 . Casings  11 ,  21  are then pressed together to arrive at the arrangement shown in  FIGS. 3E and 3F . Casings  11 ,  21  are snap-fitted together by way of the lug and groove formation shown in  FIG. 3G . 
         [0027]    Termination of a cable by way of the connector will now be described. Referring to  FIG. 4 , sub-assemblies  10 ,  20  are shown having been snap-fitted together about a cable  60  and wires  30  of cable  60  have been positioned in wire receiving spaces  14  and  24 . Cable  60  is generally cylindrical and has a central axis C. Excess wire is then trimmed from the ends of wires  30  (see  FIG. 4A ). 
         [0028]    Referring to  FIG. 5 , a third sub-assembly  40  is shown which includes a carrier  41  formed from Zamak. Eight insulation-displacing contacts  42  are mounted in the carrier and are insulated from the carrier by plastic inserts. The insulation-displacing contacts are in electrical connection with plug contacts  43  which are housed in insulating contact holder  49 , which may be integral with the aforementioned plastic inserts. Carrier  41  is to be assembled with the first and second sub-assemblies to form a connector. Note that lug  45  will locate in groove  46 . Also, four lugs  47  will engage with four grooves  48 , which serve both to align sub-assembly  40  with the casings  11 ,  21  already assembled on the cable, and to resist unintentionally disengagement of the casings  11 ,  21 . Carrier  41  also includes recesses  44  which are used to retain the carrier in the assembled connector as will now be described. 
         [0029]    Referring to  FIG. 6  the connector is shown partially assembled. Carrier  41  is shown passing by flat portions  51 ,  52  of covers  22 ,  12 . To ensure right-way-around assembly, the distance between flat portions  51  and  52  and the relevant lug width are different on the opposite sides of carrier  41 , so that sub-assembly  40  will be assemblable only in its correct position. After complete insertion of carrier  41 , covers  12  and  22  are free to pivot about their respective axes to bring the wires towards the insulation-displacing contacts. As the covers  22 ,  12  rotate, cam portions  54 ,  53  of the covers come into engagement with recesses  44  of carrier  41 . The covers  22 ,  12  are moved towards their closed position by hand and are pushed to their closed position by gripping about the entire assembly with pliers and squeezing so that the wires are properly engaged with the insulation-displacing contacts. 
         [0030]    Referring to  FIG. 7 , the connector is shown fully assembled. The covers, casings and carrier serve to completely surround the inside of the connector, thus shielding the wires inside the connector from electromagnetic interference. 
         [0031]    Referring to  FIGS. 8 and 9 , lacing fixture  16  and contact holder  49  are shown. When the covers of the connector are closed, the lip  84  of lacing fixture  16  snaps into the recess  85  on the contact holder, thus helping to keep the covers in the closed position. 
         [0032]      FIGS. 10 to 14  show a female or jack type connector, which is similar in construction to the male or plug type connector shown in  FIGS. 5 to 7 , and is intended to mate with the plug type connector. The main difference of the jack connector from the plug connector is found in the contact carrier  140 . It can be seen that contact carrier  140  provides a female type connection in the form of a recess generally indicated by arrow  160  which accommodates the male type connector previously described. Recess  160  may be protected by dust cover  150 . 
         [0033]      FIG. 15  illustrates the aforementioned preferred toothed spring flanges  15  in the upper and lower cable-gripping sub-assemblies  11 ,  21 . 
         [0034]      FIG. 16  illustrates the addition of ribs  410  in the carrier  41  and slots  120 ,  220  in the hinged covers  12 ,  22 , which ribs snap-fit into the slots to hold the covers  12 ,  22  releasably in the closed position around the contact carrier  41 . 
         [0035]    In the above described embodiments, the end of the finished connector which bears the plug contacts extends away from the cable substantially in line with the axis of the cable. However, alternative constructions where the plug contacts extend at an angle to the axis of the cable may be employed. 
         [0036]    In the embodiments described above, the electrically shielding parts are formed from Zamak, but other metals or electrically conductive materials could be used. A mould-over process may be used to form these components from a metal sheet surrounded by a moulded plastics material. Parts made of plastics in the embodiments described above could alternatively be made of other dielectric materials. In the embodiments described above, connectors with eight sets of contacts are described, but other numbers of contacts could be used, even odd numbers, and the insulation-displacing contacts described could be replaced by other types of contacts as previously mentioned. The cable may include a foil shield or a braided shield, or both foil and braided shields could be present. 
         [0037]    In the embodiments described above the cable-surrounding casings were of identical (“mirror image”) construction. Alternatively, casings of dissimilar construction could be used, provided that they are dimensioned to mate together in an appropriate manner. The casings may be provided as separate components, or could be provided as a hinged component including two half shells joined along one side of their length. 
         [0038]    Finally, it is to be appreciated that various alterations or additions may be made to the parts previously described without departing from the spirit or ambit of the present invention. The present invention includes connectors having the convenient pivoting structure of the present invention wherein some or all of the shielding parts described above may be replaced by plastics parts or other electrically insulating parts when less-shielded or unshielded connectors are required.