Abstract:
An electrical connection system for making patch cord connections that uses a hinged plug and jack mating system which results in low insertion forces and enhanced side to side stability for the patch cord connectors. This system allows the jack and most of the mated plug to be positioned behind the label and have the cordage exit the jack towards the back plane and into the troughs that are between adjacent rows of connectors, instead of out from the connector field. This keeps the label area clear of visual obstructions like cordage and connectors.

Description:
RELATED APPLICATIONS 
     The present patent application is related to 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,; U.S. patent application Ser. No. 09/577,274, entitled, “CONTACTS FOR HINGED CONNECTION SYSTEM” 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 modularized electrical connection systems. 
     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 the 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. The 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 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 slots. 
     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 are designed to remove 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 the patch cord blades, past this entrance geometry, with its high contact force, reduces the life of the patch cord blades 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 putting on a mated patch cord, the side walls on the plug 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 connecting blocks&#39; buttons can cause extensive wear of the surfaces so that the retention capability of the connecting blocks degrades after multiple insertions and removals. 
     SUMMARY 
     A device according to the principles of the invention enables simple and efficient patch cord connection. An exemplary system provides a plug having a rotatable end and a jack having a corresponding rotatable end. By engaging the rotatable plug end with the corresponding rotatable jack end, a fulcrum is established, enabling the plug to be rotated around the fulcrum point to achieve a connection. The hinging mechanism enables simple and reliable connections. 
     In an exemplary embodiment, the jack includes a front surface that faces outwards. The front surface serves as a label surface. All cord connections occur behind this label surface. Advantageously, when a plug and a jack are connected, all cordage is routed behind the label surface, providing an unobstructed view of the label surface and permitting fast and accurate identification of all jack terminations. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES 
     For a better understanding of the present invention, reference may be had to the following description of exemplary embodiments thereof, considered in conjunction with the accompanying drawings, 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; 
     FIGS.  4 ( a ) and  4 ( b ) are side cross sectional views of a plug and jack in accordance with the present invention; 
     FIG.  5 ( a ) is a partial, cross-sectional top view of a mated jack and a one pair patch cord plug in accordance with the present invention; and 
     FIG.  5 ( b ) is a partial, cross-sectional top view of a jack and a four pair patch cord plug in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION 
     This detailed description initially discusses the cross-connect system according to the principles of the invention. Exemplary embodiments of the cross connect system are then described. 
     The Cross-Connect System 
     A cross-connect system according to the invention implements 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  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 board  220 . Jack  260  has a label surface  265  that faces away from board  210 . 
     As previously shown in FIG.  1 ( e ), the connection between a plug  290  and a jack  260  is made behind 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  295  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. 
     An exemplary embodiment of the present invention can be seen in FIGS.  4 ( a ) and  4 ( b ). A plug  400  includes a plug fulcrum section  405 . A plug bearing hook  420  is seen at the end of the plug fulcrum section  405 . A jack  410  includes a hinge bearing hook  430 , that forms a hinge bearing surface  425 . The jack  410  further includes a pair of guide surfaces  460  that are parallel to each other. The guide surfaces  460  are sufficiently separated in distance in order to accommodate the width of the plug  400 . The guide surfaces  460  extend beyond the hinge bearing hook  430 . As shown in FIG.  4 ( b ), this permits the guide surfaces  460  to protect the contacts in both the plug  400  and jack  410  when they are not engaged with each other since the tips of the contacts are below the outer edges of the guide surfaces  460 . 
     Operationally, the plug  400  is mated with the jack  410  by first taking the plug bearing hook  420  and hooking it onto the hinge bearing surface  425 . Because of the extent of the guide surfaces  460 , the plug  400  slides easily into the jack  410 , thereby facilitating easy coupling of the plug bearing hook  420  and the hinge bearing hook  430 . Once the hooks are coupled, the plug  400  is rotated into its seated position by using the handle  435  as a lever to force the plug contacts  440  to mate with the jacks contacts  445 . The parallel guide surfaces  460  control the rotation path so that the contacts  440  and  445 , respectively, mate in a precise manner. More specifically, plug  400  engages the guide surfaces  460  before the plug  400  fully engages the hinge bearing hook  430 . The bearing surfaces  465  and  470  insure that the jack  410  remains fully seated onto the hinge bearing hook  430 , as plug  400  completes its rotation. The guide surfaces also provide support, holding the plug  400  in place. The guide surfaces  460  serve as a means of protecting the integrity of the coupling, making accidental de-coupling very difficult. Therefore manipulating the patch cord&#39;s cordage has very little effect on the security of the patch cord&#39;s connection. The only practical way to disengage a patch cord is by pushing on the handle  435 . 
     Design for Single or Multiple Connections 
     As illustrated in FIGS.  5 ( a ) and  5 ( b ), the jacks of the present invention permits connections with plugs of different sizes, varying from 1-pair to 4-pair. Referring to FIG.  5 ( a ), a jack  500  has at least one 4-pair connection site  510 . Jack  500  includes a partitioning wall  520  after every 4-pair connection sites  510 . Partitioning walls  520  prevent plugs from crossing over and making connections to contacts in 2 jacks simultaneously. Each 4-pair connection site  510  further includes the previously described guide walls  530 . Each site  510  can accommodate a single plug  540 , a 4-pair plug  550  as shown in FIG.  5 ( b ) or any pair size in between. 
     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.