MODULAR CONNECTOR FOR TERMINATING EMI/RFI SHIELDED CORDAGE AND CORD TERMINATED THEREBY

Abstract: An improved modular plug connector is provided with a contact as a part of the connector itself for terminating the foil shield of a cord to prevent or control the radiation of interference-causing electromagnetic and radio frequency signals from the region of the connector, such as when the cord is used in the transmission of high frequency digital-­ based data. The connector incorporating the shield terminat­ ing contact also advantageously provides for the isolation and grounding of electrostatic charge. The shield terminating con­ tact is constituted by a contact pin which passes through a side wall of the connector housing into the cord-receiving cavity to electrically engage the cord shield.

Description: This invention relates generally to electrical connectors for terminating cords and, more particularly, to so-called modular plug connectors currently being utilized in the telephone and data communications industries as well as in other applications. Modular plug connectors are generally used to terminate both flat and round cords. Generally, a flat cord has a multiplicity of insulated conductors arranged in a spaced linear array within an outer jacket, while a round cord has a multiplicity of insulated conductors arranged in a spiral array within an outer jacket. Various configurations of such connectors are disclosed in several patents assigned to Western Electric Company, Inc., such for example as U.S. Patents 3,699,498 issued October 17, 1972; 3,761,869 issued September 25, 1973; 3,860,316 issued January 14, 1975; and 3,954,320 issued May 4, 1976. Another advantageous configuration of a modular plug connector is illustrated in U.S. Patent No. 4, 211,462 issued July 8, 1980 and assigned to Stewart Stamping Corporation, the assignee of the present application. Although such connectors have been made from two housing components bonded together (see, e.g., U.S. Patent No. 3,761,869), it appears preferable to manufacture such connectors using a so-called unipartite or integrally molded housing (see, e.g., U.S. Patent No. 3,998,514). A modular plug connector generally includes a housing formed of dielectric material and which defines an internal cord receiving cavity into which the end of a cord is inserted through a cord-receiving aperture formed at one of the housing ends. The cord-receiving cavity includes a jacket-receiving portion adjacent the aperture and a communicating conductor-receiving portion into which the individual insulated conductors, from which the outer jacket has been stripped, are received. A plurality of flat contact terminals, corresponding in number to the number of conductors of the cord, are inserted into individual slots defined in the housing, each terminal being aligned with and electrically engaging a respective conductor. The conductors are generally of tinsel, stranded or solid construction while the terminals have blade-like portions which engage respective conductors in a solderless connection. The flat terminals have edges which are exposed externally of the housing for engagement with respective aligned wire contact elements provided in a jack receptacle. The cord end is secured to the connector by jacket anchoring and strain relief portions integrally hinged with the housing and movable against the cord so as to prevent separation of the connector from the cord during customer use as well as to provide strain-relief facilities for the conductors and jacket. Modular plug connectors of the type described above are finding increased use in terminating multi-conductor cords through which digital information is transmitted. For example, modular plug connectors are finding increased use in terminating multi-conductor cordage used in home and office computers for connecting the computers with peripheral components, in data communication applications generally, in electronic games, in telephone communication networds and in similar digital applications. It is now recognized that digital technology-based electronic equipment is a major source of electromagnetic (EMI) and radio frequency (RFI) interference. Such interference has become a problem due at least in part to the movement away from metal and towards plastic as the material from which the connector housings are formed. Plastics generally lack the EMI/RFI shielding effectiveness inherent in metal housings. In order to prevent or at least substantially control the emission of interference-causing electromagnetic and radio frequency radiation from multi-conductor cordage used in digital-based electronic equipment and to provide at least some protection from interference-causing signals radiated from external equipment, such cordage has conventionally been provided with "shielding" in the form of a continuous sheath of conductive material between the outer insulation jacket of the cord and the insulated conductors, the shield surrounding and enclosing the conductors along their length. The shield can be formed of any suitable conductive material. such as aluminum foil having a thickness of about 0,008mm (0.3 )applied to treated Mylar (R) having a thickness of about 0,025mm (1) or aluminum foil alone. Shields formed of braided metallic material have also been used in this connection. The shield acts to suppress or contain the interference-causing electro-magnetic and radio frequency signals radiating outwardly from the conductors and, conversely, to prevent such high frequency signals radiated from external equipment from causing interference in the conductors. When a shielded cord of the type described above is terminated by a modular plug connector, a so-called "drain wire" has conventionally been employed to ground the shield. The drain wire extends through the cord in electrical engagement with the conductive shield and is grounded by passing its end out of the connector and connecting it to a grounded terminal. In this manner, the shield is in effect terminated so that high frequency signals and any electrostatic charge conducted through the shield are "drained", i.e., grounded to thereby control the radiation or discharge thereof. However, this technique has not satisfactorily eliminated the problem of interference caused by such radiation. Specifically, it has been found that there is still a tendency for EMI and RFI to result from the leakage of electromagnetic and radio frequency radiation signals from the cordage in the region at which the modular plug connector is inserted into the jack socket. Moreoever, it is not uncommon for high frequency signals radiated from nearby equipment to pass through the jack and cause interference in the cord connectors. The problem of leaking signals described above has become quite important and has in fact led to the recent issuance of governmental regulations specifying emission level limitations especially in connection with any electronic device that uses or generates pulses or timing signals at a rate in excess of 10,000 pulses per second. Moreover, since the shield is a current conductor, there is a danger of an electrostatic discharge occurring during operation of the equipment. Such a discharge comprises a high voltage discharge which arcs across the contacts of the connector and has the possible effect of shorting the electronic circuitry. A flat ribbon cable shield attemping to overcome this problem is disclosed in U.S. Patent No. 4,345,811. Accordingly, one object of the present invention is to provide a new and improved modular plug connector for terminating EMI/RFI shielded cordage. Another object of the present invention is to provide a new and improved modular plug connector for terminating EMI/RFI shielded cordage which effectively controls the radiation of high frequency signals from the region at which the modular plug connector is inserted in the jack socket and which protects the cordage from high frequency signals radiated by extraneous equipment. Still another object of the present invention is to provide a new and improved modular plug connector for terminating EMI/RFI shielded cordage wherein the modular plug connector itself incorporates means for terminating the EMI/RFI shield. Yet another object of the present invention is to provide a new and improved modular plug connector for terminating EMI/RFI shielded cordage which is easy to manufacture and is reliable in operation. A further object of the present invention is to provide a new and improved modular plug connector for terminating EMI/RFI shielded cordage which will effectively drain electrostatic charge from the shield without the danger of damaging internal circuitry. Briefly, in accordance with the present invention, these and other objects are attained by providing cord shield terminating means extending through the housing of the modular plug connector wherein respective outer and inner portions of the shield terminating means extend exteriorly of the housing and into the region of the cord receiving cavity defined therein, respectively. According to the preferred embodiment the shield terminating means comprise conductive means adapted to reliably electrically engage with an exposed area of the shield sheath when the end of the cord is secured to the modular connector. When the modular plug connector is inserted into the jack socket, the outer portion of the shield terminating means electrically engages a grounded contact suitably provided in the socket so that the EMI, RFI and electrstatic voltage (ESV) conducted through the shield sheath is conducted to ground thereby preventing the radiation or leakage of EMI and RFI through the spaces between the connector and the jack socket and which prevents discharge of the electrostatic voltage. In one preferred embodiment, the housing of the modular plug connector is formed of a dielectric material and has walls which define a cord receiving cavity therein into which the end of a flat cord is insertable. The cavity includes a conductor-receiving portion adapted to receive through a cord-receiving aperture a plurality of conductors extending from the end of a shielded cord from which the jacket has been stripped and a jacket-receiving portion adapted to receive the jacketed portion of the cord adjacent the conductors. The conductors are respectively located within parallelly extending troughs formed in the conductor-receiving portion of the cavity which themselves respectively communicate with aligned openings or slots formed in the housing adapted to receive flat contact terminals which electrically couple with the respective conductors. At least one and preferably two anchoring members extend transversely across the housing in respective openings which communicate with the cord-receiving cavity and which are integrally connected to the housing through a plastic hinge and a severable web extending between opposed transverse edges of the anchoring members and adjacent walls of the respective openings. The anchoring members each include a surface adapted to engage the cord upon suitable tools urging the same inwardly towards the cord receiving cavity. According to one preferred embodiment of the invention, a passage is formed through a side wall of the housing opening at the housing exterior and into the cord-receiving cavity. A contact formed of a suitably conductive material is situated in the passage so that an outer portion thereof is exposed at the exterior of the housing and so that an inner portion of the contact extends to at least a slight extent into the cord-receiving cavity, preferably in alignment with one of the anchoring members of the housing. The shielded cord is inserted into the cord-receiving cavity such that an area of the shield sheath from which the outer cord jacket has been stripped overlies the inner portion of the contact. The aligned anchoring member, when moved into the cord-receiving cavity, forces the exposed shield sheath against the inner portion of the contact to provide a secure electrical engagement therewith. Thus, upon insertion of the cord within the cord-receiving cavity and subsequent inward forcing of the anchoring member, a reliable electrical termination of the shield sheath by the modular plug connector is accomplished. The jack is provided with a suitable ground contact which engages the outer portion of the contact when the connector is inserted into the jack socket to lead the EMI. RFI and ESV from the shield to ground and thereby prevent leakage from the connector. In another embodiment, the cord shield terminating means are constituted by an open passage formed in the housing providing clear communication between the cord-receiving cavity and the exterior of the connector. The opening is positioned and sized to receive, upon insertion of the connector into the socket, a ground jack contact which engages the shield sheath. In accordance with another embodiment, a shield terminating contact pin is accommodated within a passage formed through a region of a side wall of the connector, opening at one end exteriorly of the housing and at its other end in an open region of the cord- receiving cavity to facilitate manufacture of the connector and at a position wherein the shield will electrically engage the contact pin when the cord is terminated. In particular, the contact pin accommodating passage is formed through a side wall of the modular plug connector at a region whereby it fully opens into an upper region of the cord-receiving cavity at a location so that the shield will be forcefully urged into electrical engagement with the contact pin situated in the passage when the cord is terminated. Thus, the contact pin accommodating passage opens into a fully open cavity and the manufacturing problems inherent in the previously suggested embodiments as discussed above are eliminated. When the modular plug connector is inserted into an appropriate receptable, the outer exposed head of the contact pin electrically engages a grounded member, such as a jack contact, so that high frequency signals and any electrostatic charge conducted through the shield are conducted to ground thereby controlling the radiation of electromagnetic and radio frequency signals. A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily understood by reference to the following detailed description when considered in connection with the accompanying drawings in which: Fig. 1 is a perspective view of a modular plug connector housing constructed in accordance with one embodiment of the present invention; Fig. 2 is a longitudinal section view taken along line 2-2 of Fig. 1; Fig. 3 is a transverse section view taken along line 3-3 of Fig. 2 with the shielded cord inserted within the cord-receiving cavity and prior to the securement of the cord within the housing; Fig. 4 is a longitudinal section view of a modular plug connector according to the present invention incorporating the housing of Fig. 2 with the shielded cordage inserted within the cord-receiving cavity and wherein the anchoring members of the connector having just been moved by illustrated tooling to secure the cord within the cavity; Fig. 5 is a section view taken along line 5-5 of Fig. 4; Fig. 6 is an enlarged section view of the particular conductive shield terminating means constituting a component of the embodiment of the modular plug connector of Figs. 1-5; Fig. 7 is a perspective view of another embodiment of a modular plug connector housing in accordance with the present invention; Fig. 8 is a section view taken along line 8-8 of Fig. 7 and illustrating the completed connector inserted within a jack socket; Fig. 9 is a perspective view of still another embodiment of a modular plug connector housing in accordance with the invention and showing another form of the conductor shield terminating means inserted in position; and Fig. 10 is a section view taken along line 10-10 of Fig. 9 with the shielded cord secured within the connector; Fig. 11 is a perspective schematic view of a modular plug connector housing constructed in accordance with the present invention; Fig. 12 is a longitudinal section view taken along line 2-2 of Fig. 1 and illustrating the end of a shielded multi-conductor cord inserted within the cord-receiving cavity of the connector housing with a portion of the shield being exposed; Fig. 12A is an enlarged detail view of the portions of the shield and contact pin shown in the area designated A in Fig. 2; Fig. 13 is a longitudinal section view of a modular plug connector incorporating the housing shown in Figs. 1 and 2 shown after termination of the inserted cord; Fig. 14 is a section view taken along line 4-4 of Fig.3; Fig. 15 is a section view taken along line 5-5 of Fig.3; and Fig. 16 is a section view of the modular plug connector inserted into the receptacle of a jack provided with a grounded contact for electrically engaging the shield terminating contact pin of the modular plug connector. Referring now to the drawings wherein like reference characters designate identical or corresponding parts throughout the several views, more particularly to the embodiment of the invention illustrated in Figs. 1-6, a modular plug connector housing, generally designated 10, is illustrated which has been improved in accordance with the present invention through the incorporation of means for terminating a cord shield, generally designated 12. It is understood that the construction of the housing per se and the connector of which it forms a part are substantially conventional and known to those skilled in the art as that type of modular plug connector finding greatly increasing use not only in connection with the telephone industry but also in virtually all data communication areas. The incorporation of means for terminating a cord shield in the modular plug connector provides a vast improvement in the shielding which can be obtained against radiation of electromagnetic and radio frequency interference plus ESV from cordage terminated by such modular plug connectors and, therefore, renders such connectors especially suitable for use with digital-based electronic equipment when the radiation of interference at cord connections has become a problem. The construction of housing 10 of the modular plug connector will be briefly described. It is again noted that such construction is conventional and in this connection reference is made to the above-mentioned U.S. Patent 4,211,462 of Stewart Stamping Corporation which describes this housing construction in greater detail and the disclosure of said patent is hereby incorporated by reference herein. It is of course understood that the invention is not limited to the particular construction of the housing shown and described. The housing 10 is a rigid unipartite member formed of a suitable dielectric by conventional injection molding techniques. The housing 10 may be made of materials such, for example, as polycarbonate, polyamide, polystyrene, or polyester elastomers or related polymers such as ABS resin. The housing 10 has a closed forward free end 14, a cord receiving rearward end 16 and a terminal-receiving side 18 for receiving flat contact terminals 20 (Fig. 4). The housing 10 defines a longitudinally extending cord-receiving cavity 22 which externally opens through a cord-receiving aperture 24 formed in the rearward end 16 of housing 10. The cord-receiving cavity includes a forward conductor-receiving portion 26 and a rearward enlarged jacket-receiving portion 28. The cavity 22 substantially encloses the entire end section of the cord with the terminal end portions of the conductors (having the jacket stripped there-from) being received in the conductor-receiving portion 26 and the adjacent jacketed portion of the cord being received within the jacket-receiving portion 28. It is important to precisely locate the cord conductors 30 (Fig. 3-5) so that they are in direct aligned relationship with respective slots formed in the terminal receiving side 18 which receive respective flat contact terminals 20. For this reason partitions 32 and upper and lower ridges 34-36 extend through the conductor-receiving portion 26 to guide the end regions of respective conductors 30 into corresponding conductor troughs 37. A plurality of parallely spaced, longitudinally extending terminal-receiving slots 38 are formed through the terminal-receiving side 18 of housing 10, each slot 38 being aligned over a respective one of the conductor-receiving troughs 37. A pair of inwardly extending shoulders 40 and 42 (Fig. 2) are situated at about the mid-height of each slot 38. Each slot 38 is dimensioned so as to snugly receive a respective flat contact terminal 20 as described below. Referring to Fig. 4, each terminal 20 is constructed of an electrical conductive material, such as gold plated phosphor bronze. The terminal 20 has a flat conductor portion including a pair of insulation-piercing tangs 44. Each of the terminals are formed with a pair of outwardly extending shoulders 46 and 48. When a terminal 20 is inserted into an associated terminal-receiving slot 38, the points of tangs 44 of each terminal penetrate through a respective conductor 30 and become embedded in the lower wall 62 of the conductor-receiving portion 26 prior to terminal shoulders 46 and 48 engaging shoulders 40 and 42. The housing 10 is also constructed with means for both securing the connector to the cord and for providing strain relief for the jacket and conductors. A jacket anchoring member 50 is integrally connected to housing 10 through a plastic hinge 52 (Fig.2) and initially by a frangible portion 54 which supports the jacket anchoring member 50 in its initial position shown in Fig. 2 when a cord is receivable within cavity 22. The frangible portion 54 is constructed so as to shear upon the application of an inwardly directed force thereon by a suitable tool so that the jacket anchoring member can pivot about hinge 52 to engage the cord jacket. A conductor-anchoring member 56 is formed forwardly of the jacket-anchoring member 50 and extends transversely over the entire width of the conductor-receiving portion 26 of cavity 22. The conductor-anchoring member 56 is integrally connected to the housing 10 along its forward and rearward sides. The surfaces of the jacket and conductor anchoring members 50 and 56 may be formed with a plurality of parallel concave channels 58 and 60 respectively which advantageously enhance the securement of the cord in the housing as described in U.S. Patent 4,211,462. Prior to describing the improvement of the present invention, a typical assembly of the modular plug connector and securement to a cord will be described. Referring to Fig. 4, the end of a cord 58, which is shielded in a manner described below, is inserted through aperture 24 into the cord-receiving cavity 22 of housing 10. A certain length of the jacket 60 is stripped from the cord 58 so that as the cord is fully inserted into the cavity 22, respective insulated conductors 30 are separated and guided into respective troughs 37 aligned with respective terminal-receiving slots 38 and such that the conductors pass below the conductor-anchoring member 56. Terminals 20 are inserted into respective slots 38 and driven towards the conductors so that the tangs 44 of each terminal 20 penetrate the insulation of each conductor thereby making electrical connection therewith and until the points of the tangs become embedded in the bottom wall 62 and terminal shoulders 56 and 58 engage housing shoulders 40 and 42. The jacket and conductor-anchoring members 50 and 56 are driven into the conductor-receiving cavity by means of a suitable tool 64 (Fig. 4). The frangible portion 54 shears so that the jacket-anchoring member 50 pivots into engagement with the jacket 60 and cord 58 to provide a reliable mechanical securement of the cord to the connector. Similarly, one of the integral connections of the conductor-anchoring member 56 to the housing is sheared and the conductor-anchoring member moves against the conductors 30 to provide strain relief for the conductors. The anchoring members are locked in the cord-engaging positions shown in Fig. 4 by suitable locking structure provided in the housing 10 as described in U.S. Patent 4,211,462. The construction and assembly of the modular plug connector and termination of the cord thereby described above is conventional. The improvement according to the present invention is described below. In accordance with the present invention, the modular plug connector is provided with means for terminating the shielding sheath of a cord so that electromagnetic and radio frequency interference conducted through the shield sheath can be conducted through the connector to a grounded contact in the socket. Generally, the cord shield terminating means extends through the housing of the modular plug connector such that respective inner and outer portions thereof extend exteriorly of the housing and into the region of the cord-receiving cavity respectively. Referring to Figs. 3-5, the shielded cord 58 comprises the plurality of insulated conductors 30 within the jacket 60. In order to prevent radiation of interference from the cord 58, such as when the conductors transmit high frequency digital information, a shielding in the form of a sheath 66 of conductive material, such as aluminum foil or the like, encloses the insulated conductors 30 along their length. Such shielding is of course conventional. In the embodiment of the invention illustrated in Figs. 1-6, the cord shield terminating means, generally designated 12, is constituted by a contact 68 formed of electrically conductive material, such as gold plated phosphor bronze, which extends through a passage 70 which opens to the housing exterior and into the cord-receiving cavity 22 of the modular plug connector. In particular, the passage 70 is formed by an opening 70a in a side wall 72 of housing 10, the opening 70a continuing in the form of a channel 70b which extends transversely through the bottom wall 62. The transverse channel 70b opens along its length into the cord-receiving cavity 22. The opening 70a includes an enlarged diameter portion countersunk within the side wall 72 which receives an enlarged head 68a of the contact 68. In the illustrated embodiment, the contact 68 is in the shape of a pin-type member. The diameter of the shank 68b of contact 68 is chosen to be sufficiently large such that when the contact is situated in the passage 70, preferably by an interference fit, an upper cylindrical segment of the contact shank 68b extends above the plane of the bottom wall 62 and protrudes into the cord-receiving cavity 22 as best seen in Fig.6. In the illustrated embodiment of Figs. 1-6 and as best seen in Fig. 6, the channel 70b has a longitudinal cross-section defined by a pair of arcuate segments 74 and 76 and a pair of inwardly extnding linear segments 78 forming a throat through which the protruding cylindrical segment of the contact extends. This configuration facilitates insertion of the contact 68 into the passage 70 with an interference fit while preventing the shank 68b of contact 68 from working loose from the channel 70b. As noted above, the diameter of the contact shank 68b is chosen so that an upper cylindrical segment thereof protrudes into the cord-receiving cavity and as best seen in Fig. 3, the contact extends to about the mid-region of the transverse dimension of the cord-receiving cavity. Still referring to Fig. 6, typical dimensions of the components may , be follows: the diameter D of the contact shank is about 0.8mm (.032 inches) the linear length L of the cylindrical segment of the contact shank which extends or protrudes into the cord-receiving cavity is about 0.6mm(.023 inches) and the height H of the protruding cylindrical segment of the contact is about .004 inches. A longitudinal groove 80 (Fig. 1) is formed in the outer surface of the housing side wall 72 and intersects the head 68a of contact 68 for purposes described below. With the improved construction of the modular plug connector described above, it will be seen that the termination of the shielded cord in the manner described above will simultaneously provide a termination of the shielding sheath so that EMI, RFI, and ESV conducted through the shield sheath can be conducted through the modular plug connector to a ground contact in the socket. More particularly, prior to the termination of the cord, the jacket 60 is stripped from the end of the cord 58 so as to leave a length of the shielded sheath 66 (Fig. 4) at the region of the cord-receiving cavity 22 immediately rearward of the troughs 37 defined by partitions 32 and ridges 34 and 36 overlying the shank 68b of contact 68. As seen in Fig. 3, prior to driving the conductor-anchoring member 56 to its locking position shown in Fig. 4, the sheath rests against the protruding cylindrical segment of the contact shank 68b and is situated beneath the conductor-anchoring member 56. The terminals 20 are inserted as described above and the jacket and conductor-anchoring members 50 and 56 are driven to their locking position by the tools 65. As seen in Figs. 4 and 5, the downward movement of the conductor-anchoring member 56 not only provides strain relief for the conductors and sheath but additionally serves to force the sheath 66 firmly into engagement with the protruding cylindrical segment of the contact shank 68b thereby insuring a reliable electrical communication between the contact 68 and the sheath 66. The modular plug connector is thus secured to the end of the cord and is inserted into the socket 82 of a jack 84 as seen in Fig. 5. It is of course understood that the other end of the cord may be similarly terminated. The jack 84 is conventional in that it is provided with a linear array of contacts (not shown) adapted to engage the upper edges of respective contact terminals 20 through the upper regions of slots 38 to effect an electrical connection. However, the jack 85 is also provided with a grounded contact 86 adapted to be received and guided within the groove 80 formed in the side wall 72 as the modular plug connector is inserted into the socket 82. When the modular plug connector has been fully inserted into the socket, the grounding contact 86 engages the head 68a of contact 68. It will be readily understood from the foregoing that electromagnetic radio frequency interference and ESV conducted in the shield sheath 66 will be conducted through the modular plug connector by the contact 68 and through the jack contact 86 to ground. In this manner, the possibility of interference leakage from the region of the connector is effectively eliminated. The construction is extremely economical in manufacture and eliminates the need for the conventional "drain wire". The electrical contact between the shield sheath and the contact is reliably maintained by the positioning of the contact in opposed relationship to the conductor-anchoring member so that when the conductor-anchoring member is driven to its locked position to provide strain relief as is conventional, it also forcibly forces the shield sheath against the conductive contact. Referring now to the embodiment illustrated in Figs. 9 and 10 wherein elements corresponding to those described above in connection with the embodiment of Figs. 1-6 have been designated by the same reference numerals, primed, the cord shield terminating means 12' is constituted by a strip member 88 formed of an electrically conductive material which extends through a passage 90 which opens to the housing exterior and into the cord-receiving cavity 22 of the modular plug connector. The strip member 88 comprises a shank portion 92 having a plurality of barbs 92a formed in its upwardly facing surface and a bent head portion 94 adapted to close the opening 90a of passage 90 and which protrudes somewhat to the exterior of the housing 10'. The channel portion 90b of passage 90, which may be shallower than the channel 70b of passage 70, receives the shank portion 92 of the strip member 88. When the conductor-anchoring member 56' is driven to its locked position as seen in Fig. 10, the sheath 66 electrically communicates with the strip member 88. Removal of the strip member 88 from the passage 90 is prevented through the penetration of the barbs 92a in the sheath 66. Accordingly, an interference fit is not required in this embodiment. The grounded jack contact is adapted to electrically engage the head portion 94 of the strip member 88 when the modular plug connector is inserted into the jack socket. Referring now to the embodiment illustrated in Figs. 7 and 8, and wherein components corresponding to like components in the embodiment of Figs. 1-6 are designated by the same reference numeral, double primed, the cord shield terminating means 12" comprises an aperture 96 formed in the side wall 98 of the modular plug connector housing 10" which extends through the side wall 98, respective outer and inner ends of the aperture 96 opening exteriorly of the housing and into the region of the cord-receiving cavity defined there, respectively. The aperture 96 has a relatively longitudinally elongate configuration and is aligned with a guide groove 80" formed in side wall 98. In this embodiment, the grounded jack contact, designated 100 in Fig. 8, is formed with a bent contact portion 100a which is adapted to be received in and pass through the aperture 96 when the modular plug connector is fully inserted into the jack socket. In this manner, the contact portion 100a of jack contact 100 makes direct electrical contact with the shield sheath 66 to conduct any electromagnetic and radio frequency interference conducted through the sheath to ground. Although this embodiment is somewhat more economical in manufacture than the previously described embodiments, it is not as preferred since the aperture 96 provides access to the cord-receiving cavity through which contaminants may enter. Referring now to the embodiment illustrated in Figs.11-16, the construction of housing 110 of the modular plug connector will be briefly described. It is again noted that such construction is conventional and in this connection reference is made to the above-mentioned U.S. Patent 4,211,462 of Stewart Stamping Corporation which described a typical housing construction in greater detail and the disclosure of said patent is hereby incorporated by reference herein. It is of course understood that the invention is not limited to the particular construction of the housing shown and described. The housing 110 is a rigid unipartite member formed of a suitable dielectric by conventional injection molding techniques. The housing 110 may be made of materials such, for example, as polycarbonate, polyamide, polystyrene, or polyester elastomers or related polymers such as ABS resin. The housing 110 has a closed forward free end 114, a cord receiving rearward end 116 and a terminal-receiving side 118 for receiving flat contact terminals 120 (Fig. 13). The housing 110 defines a longitudinally extending cord-receiving cavity 122 which externally opens through a cord-receiving aperture 124 formed in the rearward end 116 of housing 110. The cord-receiving cavity includes a forward conductor-receiving portion 126 and a rearward enlarged jacket-receiving portion 128. The cavity 122 substantially encloses the entire end section of the cord with the terminal end portions of the conductors (having the jacket stripped therefrom) being received in the conductor-receiving portion 126 and the adjacent jacketed portion of the cord being received within the jacket-receiving portion 128. It is important to precisely locate the cord conductors 130 so that they are in direct aligned relationship with the respective slots formed in the terminal receiving side 118 which receive respective flat contact terminals 120. For this reason partitions 132 and upper and lower ridges 134, 136 extend through the conductor-receiving portion 126 to guide the end regions of respective conductors 130 into corresponding conductor troughs defined thereby. A plurality of parallely spaced, longitudinally extending terminal-receiving slots 138 are formed through the terminal-receiving side 118 of housing 110, each slot 138 being aligned over a respective one of the conductor-receiving troughs. A pair of inwardly extending shoulders 140 and 142 (Fig. 12) are situated at about the mid-height of each slot 138. Each slot 138 is dimensioned so as to snugly receive a respective flat contact terminal 120 as described below. Referring to Fig. 13, each terminal 120 is constructed of an electrical conductive material, such as gold plated phosphor bronze. The terminal 120 has a flat conductor portion including a pair of insulation-piercing tangs 144. Each of the terminals are formed with a pair of outwardly extending shoulders 146 and 148. When a terminal 120 is inserted into an associated terminal-receiving slot 138, the points of tangs 144 of each terminal penetrate through a respective conductor 130 and become embedded in the lower wall 162 of the conductor-receiving portion 126 prior to terminal shoulders 146 and 148 engaging shoulders 140 and 142. The housing 110 is also constructed with means for both securing the connector to the cord and for providing strain relief for the jacket and conductors. A jacket anchoring member 150 is integrally connected to housing 110 through a plastic hinge 152 and initially by a frangible portion 154 (Fig. 12) which supports the jacket anchoring member 150 in its initial position shown in Fig. 2 when a cord is receivable within cavity 122. The frangible portion 154 is constructed so as to shear upon the application of an inwardly directed force thereon by a suitable tool so that the jacket anchoring member can pivot about hinge 152 to engage the cord jacket. A conductor-anchoring member 156 is formed forwardly of the jacket-anchoring member 150 and extends transversely over the entire width of the conductor-receiving portion 126 of cavity 122. The conductor-anchoring member 156 is integrally connected to the housing 110 along its forward and rearward sides. The surfaces of the jacket and conductor anchoring members 150 and 156 may be formed with a plurality of parallel concave channels 158 and 160 respectively which advantageously enhance the securement of the cord in the housing as described in U.S. Patent 4,211,462. Prior to describing the improvement of the present invention, a typical assembly of the modular plug connector and securement to a cord will be described. Referring to Fig. 13, the end of a cord 113, which is shielded in a manner described below, is inserted through aperture 124 into the cord-receiving cavity 122 of housing 110. A certain length of the jacket 166 is stripped from the cord 113 so that as the cord is fully inserted into the cavity 122, respective insulated conductors 130 are separated and guided into respective troughs aligned with respective terminal-receiving slots 138 and such that the conductors become situated below the conductor-anchoring member 156 and the cord jacket becomes situated below the jacket anchoring member 150. Terminals 120 are inserted into respective slots 138 and driven towards the conductors so that the tangs 144 of each terminal 120 penetrate the insulation of each conductor thereby making electrical connection therewith and until the points of the tangs become embedded in the bottom wall 162 and terminal shoulders 156 and 158 engage housing shoulders 140 and 142. The jacket and conductor-anchoring members 150 and 156 are driven downwardly by means of a suitable tool 162. The frangible portion 154 shears so that the jacket-anchoring member 150 pivots into engagement with the jacket 166 of cord 158 to provide a reliable mechanical securement of the cord to the connector. Similarly, one of the web-like portions connecting the conductor-anchoring member 156 to the housing is sheared and the conductor-anchoring member moves against the conductors 130 to provide strain relief for the conductors. The anchoring members are locked in the cord-engaging positions shown in Fig. 14 by suitable conventional locking structure. The construction of the connector housing, assembly of the modular plug connector incorporating the same and the termination of the cord by the connector as described above is conventional. The improvement according to the present invention is described below. In accordance with the present invention, the modular plug connector is provided with means for terminating the EMI/RFI shield of a cord as a part of the connector itself so that electromagnetic and radio frequency interference-causing signals conducted through the shield can be conducted through the connector to a grounded contact in a jack. Referring to Figs. 11, 12 and 14, the housing 110 in accordance with the invention is molded so that the downwardly facing surface 170 of cord-receiving cavity 122 in the region of the transition between the conductor and jacket-receiving portions 126 and 128 has a substantially quarter-cylindrical surface segment 172. The cylindrical surface segment 172 forms a bearing surface for the shank 174 of the shield terminating contact pin 176. A circular opening 178 is formed in a side wall 180 of housing 110 coaxial with the cylindrical surface segment 172 and having a radius substantially equal to the radius of curvature of the cylindrical surface segment 172. It is thus seen tnat the opening 178 opens at one end exteriorly of the housing and at its other end in an open region of the cord-receiving cavity 122 thereby facilitating its formation without pieces of plastic which are cut from the housing during formation passing into the cord-receiving cavity. The contact pin 176 is formed of electrically conductive material, such as gold plated phosphor bronze. Contact pin 176 includes the cylindrical shank 174 having a radius substantially equal or slightly smaller than the radius of opening 178 and the radius of curvature of the cylindrical surface segment 172, and an enlarged disc-shaped head 182 at one end of the shank 174. The other end of the shank 174 is passed through the circular opening or passage 178 in housing side wall 180 until the head 182 abuts against the outer surface of side wall 180. It will be understood that a segment of the surface of the contact pin shank 174 will be contiguous with the cylindrical surface segment 172 of the downwardly facing surface 170 of cord-receiving cavity 122 as seen in the figures. The contact pin will be held in this position through its engagement within the passage 178. Referring to Figs. 12 and 12A, the cord 113 in the illustrated embodiment includes a plurality of insulated conductors 130 surrounded by a shield constituted by a sheath of aluminum foil 184 (Fig. 12A) applied to a sheath of Mylar (R) 186. The shield 112 extends along the length of the cord 113 with the aluminum foil 184 next to the conductors 130. Prior to the insertion of the end of cord 113 into the cord-receiving cavity 122, the end portion of the outer insulation jacket 166 is removed exposing the shield 112. The portion of the exposed shield 112 which overlies the conductors 130 is folded back over the outer surface of jacket 166 as seen in Fig. 12 so that the aluminum foil layer 184 is exposed and faces forwardly at the portion in front of the jacket 166. The remaining portions of the shield 112 can be removed if desired. With the cord end prepared as described above, it is inserted into the cord-receiving cavity 122 through entrance opening 124 so that the conductors 130 enter into respective conductor-receiving troughs as described above. At the same time, the forwardly facing exposed layer of aluminum foil 184 is urged against the surface of the shank 174 of contact pin 176 as seen in Figs.12 and 12A whereby an electrical engagement between the shield 112 and contact pin 176 is achieved. With the cord being held in position so that the aluminum foil layer 184 of the shield 112 is in tight engagement with the contact pin shank 174, the flat contact terminals 120 are inserted as described above and the jacket and conductor-anchoring members 150 and 156 driven downwardly to their locked position by tools 164 as seen in Fig. 13. Locking of the jacket-anchoring member 150 to its locked position as seen in Fig. 13 causes the portion of the jacket 166 situated forwardly thereof to be deformed and flow upwardly to substantially fill the space between the forward jacket contacting surface thereof and the downwardly facing surface 170 of the cord-receiving cavity 122 at the transition between the conductor and jacket receiving portions 126 and 128. This in turn forcefully urges the exposed portion of shield 112 against the shank 174 of contact pin 176 to provide an extremely reliable electrical engagement between the aluminum foil layer 184 of the shield and the rearwardly facing surface segment of the shank 174 of contact pin 176 as seen in Figs. 13 and 15. Moreover, a portion of the exposed shield 112 is urged under the force of the jacket-anchoring member 150 underneath the shank 174 as seen in Figs. 13 and 14 to even further enlarge the area of electrical contact between the shield and contact pin. Referring to Fig. 16, the modular plug connector terminating the end of the cord is inserted into the receptacle 188 of a suitable jack 190 provided with a linear array of contact wires (not shown) adapted to engage the upper edges of respective flat contact terminals 120 through the upper regions of slots 138 to effect electrical connections therewith. The jack 190 is also provided with a grounded contact 192 adapted to engage the head 182 of contact pin 176 when the modular plug connector is fully inserted within the receptacle 188 to thereby ground the shield 112. A channel 194 is formed in receptacle 188 to accommodate the grounded contact 192 and head 182 of contact pin 176. It will be understood from the foregoing that the electromagnetic and radio frequency interference-causing signals and any electrostatic charge present in the aluminum foil layer 184 of shield 112 will be conducted through the modular plug connector by the contact pin 176 to the grounded jack contact 192 to ground. In this manner, the possibility of leakage of interference causing signals from the region of the connector is effectively eliminated. The manufacture of the modular plug connector in accordance with the invention is facilitated by the provision that the passage or opening 178 opens into a fully opened space within the cord-receiving cavity and, moreover, the electrical contact between the shield and the contact pin is extremely reliable due to the forceful urging of the shield against the contact pin by the cord jacket under the force of the jacket-anchoring member 150.

Claims: A modular plug connector device for terminating a shielded cord having a plurality of insulated conductors enclosed within an outer jacket and a shield sheath between the jacket and conductors and enclosing the latter substantially along their length, comprising: a dielectric housing(10,10',10",110) having a forward free end (14,140)and a rearward cord input end (l6,16',16",160) having an aperture (24,24',24",124) formed therein opening into a cord-receiving cavity (22, 22',22",122) formed within the housing (10, 10',10",110) said cord-receiving cavity (22,22',22",122) having a forward conductor-receiving portion (26,126) and a rearward jacket-receiving portion (28,128), a plurality of parallely extending conductor-receiving troughs (37) extending in a longitudinal direction over a part of the conductor-receiving portion (26/126)of said cavity (22,22',22",120) a plurality of slot-like openings (38,38',38",138) adapted to receive flat contact terminals (20,120) each of said openings being aligned and communicating with a respective conductor-receiving trough; characterised by means (12, 12',12",112) extending through said housing (10,10',10",110) for terminating the cord shield sheath (66,166), whereby electromagnetic and radio frequency interference conducted in the sheath (66,166)is conducted by said shield sheath terminating means (12,12',12",112) through said housing (10,10',10",110) to prevent or at least substantially reduce leakage of the interference from the region of the modular plug connector and whereby electrostatic voltage conducted in the sheath (66,166) is conducted by said shield sheath terminating means (12,12',12",112) through said housing (10,10',10",110), to eliminate the possibility of damage to internal circuitry due to arcing or short circuiting. A modular plug connector as claimed in claim 1 characterised in that said cord shield sheath terminating means (12) comprise electrically conductive means (68) carried in a wall (72) of said housing (10) having an inner portion (68b) adapted to make electrical contact with the cord shield sheath (66) and an outer portion (68a) extending to the exterior of said housing (10). A modular plug connector as claimed in claim 2 characterised in that said electrically conductive means (68) are situated in a passage (70) formed in said housing (10), said passage (70) opening into said cord-receiving cavity (22) and to the exterior of said housing (10). A modular plug connector as claimed in claim 3 characterised in that said electrically conductive means (68) are constituted by a contact (68b) formed of electrically conductive material, said contact (68b) being situated in said passage (70) with at least a part of an inner portion thereof protruding into said cord-receiving cavity (22) and an outer part (68a) thereof being exposed to the exterior of said housing (10). A modular plug connector as claimed in claim 4 characterised in that said passage (70) includes an opening (70a) in a side wall (72) of said housing and an aligned channel (70b) formed in a bottom wall (62) of said cord-receiving cavity (22), said channel (70b) opening at a throat region into said cord-receiving cavity (22) and extending substantially transversely over at least a part of said cord-receiving cavity (22). A modular plug connector as claimed in claim 5 characterised in that said contact (68b) has a substantially cylindrical shank portion, and wherein a cylindrical segment of said shank portion extends through said throat region and protrudes into said cord-receiving cavity (22). A modular plug connector as claimed in claim 6 further including a longitudinal groove (80) formed in said housing side wall (72) in alignment with said outer portion (68b) of said contact. A modular plug connector as claimed in claim 3 characterised in that said housing (10) further includes at least one anchoring member (56) extending transversely across said housing and connected thereto for movement from an unlocking position to a locking position wherein a surface thereof is located at least partially within said conductor-receiving portion (26) of said cord-receiving cavity (22), and wherein said passage includes a channel (70b) formed in a bottom wall (62) of said conductor-receiving portion (26), said channel (70b) being situated in opposed relationship to said anchoring member (56), whereby when said anchoring member (56) is moved to said locking position it serves to simultaneously anchor the conductors in said housing and force the sheath (66) into secure electrical contact with said electrically conductive means (68). A modular plug connector as claimed in claim 1 characterised in that said cord sheath terminating means are constituted by a strip member (88) formed of electrically conductive material, said strip member (88) being situated in a passage (90) with at least an inner portion (92) thereof protruding into said cord-receiving cavity (22') and an outer part (94) thereof being exposed to the exterior of said housing (10'). A modular plug connector as claimed in claim 9 characterised in that barb means (92a) for penetrating said shield sheath (66) are provided on said inner portion (92) of said strip member (88). A modular plug connector as claimed in claim 1 characterised in that said cord sheath terminating means (12") comprise an aperture (96) formed in a wall (98) of said housing (10") communicating between said conductor receiving portion of said cord-receiving cavity (22") and the exterior of said housing (10"). A modular plug connector as claimed in claim 11 characterised in that said aperture (96) is elongated in a longitudinal direction. A modular plug connector as claimed in claim 4 characterised in that said contact (68) comprises a pin-shaped member. A modular plug connector as claimed in claim 1 characterised in that an opening (178) is formed through one of the side walls (180) of the housing (110) which opens at one of its ends at the exterior surface of said housing side wall and at the other of its ends at a fully open region of the cord-receiving cavity (122); and said cord shield terminating means comprises a contact pin (176) extending through said opening (178), said contact pin (176) having one end (182) exposed at the exterior surface of said housing side wall (180) and a shank (174) situated within said cord-receiving cavity (122) adapted to electrically engage an exposed portion of the conductive cord shield (112) to terminate the same. A modular plug connector as claimed in claim 14 characterised in that said cord-receiving cavity (122) includes a transition region between said conductor and jacket-receiving portions (126, 128) having a surface (170) facing towards the conductor receiving cavity 122, and wherein said contact pin shank (174) is situated with a segment of its surface contiguous with a segment (172) of said surface (170). A modular plug connector as claimed in claim 15 characterised in that said contact pin shank (174) is cylindrical and wherein said contiguous segment (172) of said surface (170) of said cord-receiving cavity (122) has a corresponding cylindrical shape. A modular plug connector as claimed in claim 15 characterised in that said housing (110) includes an integral jacket-anchoring member (150) situated rearwardly of said transition region and extending transversely across said housing (110) and connected thereto for movement from an unlocking position to a locking position, wherein a surface thereof is located at least partially within said jacket-receiving portion (128) of said cord-receiving cavity (122). A modular plug connector as claimed in any of claims 14 to 17, terminating a shielded cord, characterised by a cord (113) having a plurality of insulated conductors (130) enclosed within an outer jacket (166) and a conductive shield (112) between the jacket 166) and conductors (130) and enclosing the latter along their length; an end portion of said cord (113) having the jacket (166) removed therefrom to expose a portion of said conductive shield (112) and said conductors (130), said cord end portion inserted within said cord-receiving cavity (122); each of said flat contact terminals (120) electrically engaging a respective one of said cord conductors (130) in said conductor- recei ving portion (126) of said housing; and wherein said shank of said contact pin (176) electrically engages said exposed portion of said conductive shield (112).

Inventors: BRENNAN, ROBERT J., MEIGHEN, TERRENCE
Applicants: STEWART STAMPING CORPORATION (A CONNECTICUT CORPORATION)
Application year: 1984
Main classification: H01R13
IPC codes: H01R13, H01R12, H01R4