Abstract:
An electrical connection system for making patch cord connections that uses a hinged plug and jack mating system, wherein the system utilizes contact/engagement implementations that permit the plug and jack to mate on an arc. Specifically, blade and spring clip connectors are used that also result in low insertion forces and enhanced side to side stability for the patch cord connectors. The blade and spring clip connectors provide improved electrical performance and allow faster and more reliable connections. Moreover, a rotatable end structure is added adjacent to a jack cavity/engagement portion of a modular jack. A complementary rotatable end structure for the plug is also added. The plug is provided with curved engagement surfaces which permit the modular jack to mate in an arc with the plug.

Description:
RELATED APPLICATIONS 
     The present patent application is related to U.S. patent application Ser. No. 09/575,969, entitled, “HINGED CONNECTION SYSTEM”, being concurrently filed herewith and having a filing date of May 23, 2000; U.S. patent application Ser. No. 09/575,968, entitled, “SLIDING CABLE FIXTURE”, being concurrently filed herewith and having a filing date of May 23, 2000; to U.S. patent application Ser. No. 09/575,902, entitled, “CONNECTOR SYSTEM WITH RELEASABLE LATCH”, being concurrently filed herewith and having a filing date of May 23, 2000; to U.S. patent application Ser. No. 09/577,275, entitled, “SNAP-IN MODULE SYSTEM”, being concurrently filed herewith and having a filing date of May 23, 2000; to U.S. patent application Ser. No. 09/577,273, entitled, “BOARD MOUNTED JACK MODULE”, being concurrently filed herewith and having a filing date of May 23, 2000; all of which have a common inventor and assignee and being incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to electrical connection systems, and more particularly to electrical connections systems for use in telecommunications. 
     BACKGROUND OF THE INVENTION 
     In the telecommunications industry, connecting systems comprising an array of insulation displacement contacts (IDC) are typically used in telephone company central offices and office buildings for electrical connection between cables and cross-connect wiring. These electrical connection systems are used throughout the telecommunications industry in order to interconnect corresponding wires in two sets of wires. The predominant connecting systems for building terminal cross-connect systems are currently the modular Rj45 connector system and the  110  connection system or variations of these connection systems. The modular type connector systems use a plug and jack type interface for making connections. 
     The Rj45 version of a modular connector system is a 4-pair connector system that cannot be broken down to smaller increments without wasting connector positions. A patch cord connection is made to a jack by deflecting a set of cantilevered spring wires in a jack with a mating set of fixed pressure contact surfaces in the plug, as the plug is pushed into the jack with a relatively low force. As the plug completes its insertion into the jack, it automatically latches with an audible click. By gripping the exposed back end of the plug, and depressing a lever, the latch can be released. Spring loaded wire contacts within the jack essentially push the plug out. The Rj45 modular systems have a panel with a flat front face. When a patch cord is installed, the cordage comes straight out from the panel. Cross-connect distribution rings bring the cordage back in along the face of the panel. 
     The  110  connector system is designed with insulation displacement connections (IDC) for both the cable connections and the cross-connect or patching connections. Therefore, a patching connection can be made by terminating cross-connect wires in the contacts IDC slots, or by inserting patch cord blades into those contact shots. 
     This Connector System forms a connector field that is front accessible, and is designed for wall mounting. Despite this design, the  110  system can be frame mounted, with the cables fed from the front in a manner similar to wall mounting. The cables can also be fed from the back of the frame. The front access is achieved by having a cross-connect field superimposed on a cable termination field; that is, superimposed on the cable routing. Cables are routed behind the wiring blocks, either in pre-mounted channels or between the rows of wiring block support legs. Cable ends are brought through their appropriate openings in the wiring block to the cable termination surface, and the exposed cable sheath is removed. The cable conductors are fanned out as twisted pairs to their appropriate termination ports in the index strips on the front face of a wiring block. Connecting blocks, which include contacts having insulation displacement portions on two opposite ends, are brought down and snapped onto the index strip to form electrical connections between the contacts and conductors. The front surface formed by the connecting blocks is the cross-connect field. A designation strip is placed between alternate rows and is used to label the conductor terminations on the rows on either side of it. When a cross-connect field is intended for use with patch cords, 100 pair wiring blocks typically alternate with horizontal troughs, with patch cords from the upper 2 rows going into an upper trough, and patch cords from the lower 2 rows going into a lower trough. When a high percentage of patch cord positions are populated, the patch cord connectors present an unruly appearance and the labeling becomes very difficult to read, making cord location a time consuming process. 
     Patch cords in the  110  connector system have contact blades that make connection by inserting into the top IDC slots of the contact elements. The IDC is designed to remove conductor insulation as it makes contact, and to achieve a high enough contact force to make a stable long term connection to unplated wire. Repeated insertions of patch cord blades past this entrance geometry, with its high contact force, reduces the life of the patch cord blade&#39;s protective plating. This contact force (about 2 pounds) holds the patch cord blade by friction and prevents it from sliding out by about a third of a pound per contact. The contact slots are tapered so any vibration or wiggling of the patch cord would cause the blades to slowly walk out of the slots, unless something else held them in place. 
     Connecting blocks may have hemispherical buttons that match mating holes in the patch cords. By pulling on a mated patch cord, the side walls on the play end flex as they slide over the connecting blocks&#39; buttons; a snap-on/snap-off type of latch is enabled, and the plug end is disconnected. The force to overcome this latch and remove a 4-pair patch cord, with a straight pull, can be as high as 25 pounds. Removal can be effected by a side to side rocking of the patch cord. Because patch cord plugs are in close proximity to each other, removal of one patch cord can easily result in the dislodging of a neighboring patch cord. Therefore, technicians must be very deliberate and careful during cord tracing to avoid inadvertently dislodging a patch cord. Furthermore, the high friction on the buttons can cause extensive wear of the surfaces so that the retention capability of the connecting blocks degrades after multiple insertions and removals. 
     SUMMARY 
     The electrical contacts according to the principals of the invention allow for simple, modular, and efficient patch cord connection with improved electrical performance. In an exemplary embodiment, a plug having a rotatable end and a plug contact with a blade portion is provided. A jack is provided with a corresponding rotatable end and a jack contact with a spring clip portion. By engaging the rotatable plug end with the corresponding rotatable jack end, a fulcrum is established, enabling the plug to rotate around the fulcrum point and achieve a simple and reliable connection between the blade portion and the spring clip portion. The other side of the jack contact can be an insulation displacement contact to allow connectivity to cables or the jack contact can be a printed wire board contact enabling connectivity with printed wire boards. Consequently, the hinging mechanism permits simple and reliable connections to be made while the blade and spring clip portions provide excellent connectivity and electrical performance. Engagement can be fairly insensitive to the actual direction of the blade and spring clip portions, thereby allowing connections to be made in a faster and more reliable manner. 
     In another exemplary embodiment, a modular jack is used with the hinged connector system for simple and efficient patch cord connection. A rotatable end structure is added adjacent to a jack cavity/engagement portion of the modular jack. This provides a complementary rotatable end structure for the plug. Moreover, the plug is provided with curved engagement surfaces that permit the modular jack to mate in an arc with the plug. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete understanding of the present invention may be obtained from consideration of the following description in conjunction with the drawing, in which: 
     FIGS.  1 ( a )- 1 ( e ) are schematic diagrams of a plug and a jack in accordance with the present invention; 
     FIG. 2 is a side cross sectional view of a jack mounted on a printed wiring board support structure in accordance with the present invention; 
     FIGS.  3 ( a )- 3 ( c ) show multiple perspective views of the embodiment illustrated in FIG. 2; 
     FIG. 4 is a perspective view of mateable contacts for a plug and a jack in which the jack contacts mount in, and make electrical contact to a printed wiring board, in accordance with the present invention; 
     FIG. 5 are perspective views of mateable contacts for a plug and a jack where both the plug and jack contacts have JDC&#39;s to make connection to wire conductors, in accordance with the present invention; 
     FIG. 6 is a cross-sectional side view of another mated plug and jack similar to the Rj45 concept, in accordance with the present invention; 
     FIGS.  7 ( a )- 7 ( c ) illustrate, from a cross-sectional perspective, the connecting of a plug to a jack module in accordance with the present invention; and 
     FIGS.  8 ( a ) and  8 ( b ) are side views of the connecting of a plug and jack similar to the Rj45 concept, in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION 
     This detailed description initially discusses a cross connect system according to the principles of the invention. Exemplary embodiments for contact designs for use in a hinged connector system are then described. Finally, exemplary embodiments of the cross connect system are presented. 
     The Cross Connect System 
     A cross-connect system according to the invention makes a connection by implementing one end of a plug hooking onto a corresponding end of a jack to form a fulcrum. The plug then functions as a lever by rotating about that fulcrum until it mates with the jack. 
     A plug  100  is illustrated in FIG.  1 ( a ). The plug  100  includes a handle  105  on one end. When the plug  100  functions as a lever, the handle  105  serves as one end of that lever. The other end of the lever is the plug fulcrum section  120 . The plug  100  further includes a latch  110  that it is located proximate to the handle  105 . The latch extends somewhat perpendicularly from the plug  100 . A pair of contacts  115  are located between the latch  110  and the plug fulcrum section  120 . Cordage  125  is electrically connected to the contacts  115 . Although one pair of contacts  115  is shown in the plug  100 , it is understood that any plurality of contacts can be included within the plug  100 . 
     In one embodiment of the invention, cordage  125  exits plug  100  at plug fulcrum section  120 . As such, cordage  125  is automatically directed toward a back plane (not shown) through a trough  270  as detailed in FIGS.  2  and  3 ( a )-( c ). This keeps the immediate area clear of cordage  125 , thereby providing a neat appearance and making it easier for the craftsperson to locate specific jack positions. Also, because the cordage  125  is not directed straight out, the latch engagement is unaffected when cordage  125  is manipulated, as for cord tracing, for example. Latching in this configuration can be implemented using a snap action latch mechanism. 
     Referring now to FIG.  1 ( b ), a plug  130  can also have cordage  135  exit at a handle  140 . Since cordage  135  directs away from the back plane in this instance, care must be taken to keep cordage  135  from interfering with patch cord installation or removal. A wider trough may be required, and a positive latch with a release mechanism may be required. The remaining illustrations and description employ a snap action latch; however, a positive latch with a release mechanism could also be used. 
     Referring now to FIGS.  1 ( c )- 1 ( e ), mating of plug  100  to a jack  145  is illustrated. As shown, jack  145  includes a corresponding latch  150 , corresponding contacts  155  and a jack fulcrum section  160 . Referring specifically to FIG.  1 ( c ), plug fulcrum section  120  engages jack fulcrum section  160 . The angle of engagement is sufficiently offset to prevent engagement of latch  110  with corresponding latch  150  and contacts  115  with corresponding contacts  155 . Engagement of the latches and contacts is prevented until the fulcrum sections  120  and  160  are fully engaged and the plug rotated towards the jack. In one embodiment, this offset angle or rotation angle is approximately 20°. Referring now to FIGS.  1 ( d ) and  1 ( e ), handle  105  is used as a lever to rotate plug  100  towards jack  145  until corresponding latch and contact connection is achieved. 
     As illustrated in FIG.  1 ( c ), corresponding latch  150  further includes a label surface  165 . One of the advantages of the cross connect system is that label surface  165  is positioned frontward as shown below and the resulting connection is implemented behind or below label surface  165 . This implementation maximizes the area in the cross connect field that can be devoted to either the label or trough space. This advantage is shown in more detail with respect to FIGS.  2  and  3 ( a )- 3 ( c ). Referring to FIG. 2, a cross sectional view of a printed wiring board utilizing the cross connect system according to the principles of the invention is shown. Cross connect system  200  has a backplane printed wiring board  210  and at least one printed wiring board  220  connected to board  210  using support structures  230  and edge card connectors  240 . Connection blocks  250  are attached to board  210  to permit connections with conductors of cables that go to, for example, equipment or wall jacks (not shown). Specifically, a jack  260  is connected to the board  220 . Jack  260  has a label surface  265  that faces away from the board  210 . 
     As previously shown in FIG.  1 ( e ), the connection between a plug  290  and a jack  260  is made below label surface  265 . If cross connection system  200  further utilizes a scheme where cordage  285  exits at a fulcrum end  275  towards board  210  and into a trough  270 , then the only visible object beyond label surface  265  is the relatively small handle  275  of the plug  290 . This is shown in FIGS.  3 ( a )- 3 ( c ). Specifically, FIG.  3 ( a ) shows a perspective view of a cross connect system  300  with a mated plug and jack  310 . Cordage  320  exits away from label surface  330  and into a trough area  340 . FIG.  3 ( b ) shows a bottom up view of FIG.  3 ( a ) and FIG.  3 ( c ) shows a close up view of mated plug and jack  310 . FIGS.  3 ( a ) and  3 ( c ) show that label surface  330  is unobstructed except for the minor presence of handle  350  of mated plug and jack  310 . An easy to read label surface is highly valued during cord tracing and other such activities. 
     Exemplary Contacts 
     The cross connection system according to the principles of the invention uses mateable connectors that can mate by moving along an arc of a desired radius. A preferred connector positioning would be with the axis of engagement traveling perpendicular to a radial line from the pivot point to the center of engagement travel. This minimizes relative inter-contact travel perpendicular to the engagement direction. Suitable contacts for the present invention are a blade and spring clip since they are fairly insensitive to the exact direction of engagement. 
     Referring to FIG. 4, two pairs of mateable contacts are shown for use with a printed wired board based system in accordance with the connector system of the present invention. Contacts  400  include a plug contact  410  and a jack contact  420 . Plug contact  410  further includes an insulation displacement contact  412  at one end and a blade  414  at a remaining end. Insulation displacement contact  412  is used to make contact to the cordage conductors in the plugs. Blade  414  is radially aligned. Jack contact  420  further includes a spring clip  422  at one end and a printed wired board contact  424  at a remaining end. Contacts  450  are similar to contacts  400  except that jack contacts  460  are structurally inverted with respect to jack contacts  420 . 
     Referring to FIG. 5, two pairs of exemplary mateable contacts are shown. Contacts  500  and  550  include plug contacts  510  and  530  as described above, respectively. Contacts  500  include a jack contact  520  that has a spring clip  522  at one end and an insulation displacement contact  524  at a remaining end. Insulation displacement contact  524  is connected offset or staggered with respect to the radial center of jack contact  520 . As before, jack contact  570  of contacts  550  is structurally inverted with respect to jack contacts  500 . 
     In another exemplary embodiment, the contacts are provided such that a modular jack and plug system can mate on an arc. Conventional modular jacks generally comprise a one-piece plastic housing having a longitudinal cavity adapted to receive the modular plug. Associated with the housing are jack contacts adapted to engage the contacts of the plug when the latter is inserted into the jack cavity or receptacle. The contacts in current modular systems are constrained to a regulated interconnect system that must conform to geometrical constraints. These constraints prevent the use of these type of contacts in a hinged system, at least one with a small radius. Specifically, the guide surfaces in current modular systems are used for aligning the plug to an essentially straight line engagement with and into the jack. 
     Referring to FIG. 6, an exemplary embodiment of a cross connect system  600  is shown using concepts of a modular system. Cross connect system  600  includes a jack  610  and a plug  620 . Jack  610  includes a jack cavity  625  similar to those in current modular systems. Unlike current modular systems, however, jack cavity  625  now faces downward. This architecture permits jack  610  to be connected with a standard plug or plug  620 . Jack  610  also includes a label surface  630 . As shown below, all connections are made below label surface  630 . As such, label surface  630  is visible when performing maintenance or other work on the system. Jack  610  further includes a hinge bearing hook  640  for rotatably connecting with plug  620 . Hinge bearing hook  640  can be integrally incorporated into the jack housing of jack  610  or be mounted as a separate piece. Jack  610  also includes jack contacts  635 , which are situated internally with respect to jack cavity  625  and can be connected to, for example, a printed wire board  690 . The board  690  acts as a support structure for the jack  610 . The jack  610  can also be configured as a self-contained module or a snap in jack, with its own integral conductor termination ports. 
     The plug  620  includes a handle  645 , cord straining mechanism, for example, latch  695 , plug contacts  648  and a plug engagement portion  650 . Plug engagement portion in the jack and the corresponding engagement surfaces on the plug are curved to facilitate plug  620  mating in an arc with jack  610 . The plug engagement portion  650  of the jack  610  is the cavity that the plug  620  goes into. Plug  620  further includes a latch  655 . A right angle extension  660  is attached to latch  655  to make it easier to release latch  655  when plug  620  is mated with jack  610 . Moreover, plug  620  has been incorporated with a hinge to mate plug body that includes a plug bearing hook  665  and anti-snag detail  670 . The anti-snag detail  670  further includes guide surface  675  which keeps plug bearing hook  665  and hinge bearing hook  640  fully engaged after the rotation starts. The anti-snag rib  699  further prevents the portion of the plug that goes into the jack from snagging on other cords when it is pulled through a trough. 
     Referring now to FIGS.  7 ( a ) to  7 ( c ), a patch cord or plug  700  is mated with a jack  710  in accordance with the principles of the invention. The following operational description is accurate for any jack and plug utilizing the concepts of the present invention. A plug bearing hook  720  is hooked onto a hinge bearing surface  730 , formed by hinge bearing hook  725 . Plug  700  is then rotated into its seated position by using handle  735  as a lever to force plug contacts  740  to mate with jack contacts  745 . 
     Specifically, as plug  700  rotates about fulcrum point  750  toward jack  710 , plug spring latch  755  engages a latch  760  in the plug  710 , and snaps into place. Referring also to FIG. 8, guide surfaces can be seen that control the rotation path so that the contacts mate in a precise manner. Specifically, plug  700  engages the side guide surfaces  860  before plug  700  fully engages hinge bearing hook  730 . After hinge bearing hook  730  is engaged, jack  710  starts to rotate about hinge bearing hook  730 , but before there is any contact engagement, plug  700  engages the bearing housing  765  which serves as a third guide surface, insuring that jack  710  remains fully seated onto hinge bearing hook  730 , as plug  700  completes its rotation. 
     The side guide surfaces  760  extend beyond the hinge bearing hook  730  as well as the jack contacts  745 . Thus, when the plug contacts  740  are mated with the jack contacts  745 , the connections are completed below the outer edges of the side guide surfaces  760 . This protects the contacts for both the plug  700  and the jack  710 . Because the side guide surfaces  760  are separated in distance to accommodate the width of the plug  700 , the side guide surfaces also provide lateral support, holding plug  700  firmly in place. Therefore manipulating the patch cord&#39;s cordage has very little effect on the security of the connection. Pushing on handle  735  is the practical way to disengage a patch cord. The patch cord can be disengaged if the point where the cordage enters the plug is pushed in fairly hard. This would require several pounds since the mechanical advantage is working against it. 
     Numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. Details of the structure may be varied substantially without departing from the spirit of the invention and the exclusive use of all modifications that come within the scope of the appended claim is reserved.