Communications cabling system with twisted wire pairs

Information

  • Patent Grant
  • 6336826
  • Patent Number
    6,336,826
  • Date Filed
    Thursday, December 17, 1998
    26 years ago
  • Date Issued
    Tuesday, January 8, 2002
    23 years ago
Abstract
A modular communications cable assembly comprises first and second connectors, each having an elongated array of electrical contacts, and high-speed (e.g., data) and low-speed (e.g., voice) twisted wire pairs extending between the first and second connectors and terminated to the electrical contacts. Electrical contacts are skipped (or left empty) between the high-speed wire pairs to reduce cross-talk., but no electrical contacts are skipped between the low-speed wire pairs. An electrically conductive member with pins may be used to electrically couple the skipped contacts together to further reduce cross-talk. In another aspect, a modular communications cable assembly provides a plurality of communication circuits to a cluster of workstations. The cable assembly comprises an upstream connector and at least one downstream connector, with a plurality of high-speed cable segments and at least one low-speed cable segment extending between the upstream and downstream connectors. Each high-speed cable segment contains a set of twisted wire pairs for high-speed communication, and the at least one low-speed cable segment provides a plurality of sets of twisted wire pairs for low-speed communication. Each communication circuit comprises one set of twisted pairs from the high-speed cable segments and one set of twisted pairs from the at least one low-speed cable segment. Colors are used to facilitate the proper joining of cable assemblies, e.g., black connectors are joined to red connectors. A circuit breakout assembly (FIG. 13) is used and includes a body, an in-feed connector and a plurality of breakout connectors for providing communication circuits to a cluster of workstations.
Description




FIELD OF THE INVENTION




The present invention relates to telecommunications cabling and devices for transmitting analog and digital electrical signals. In particular, the present invention relates to a modular cable system for providing data and voice communications to a plurality of workstations, which is easy to install and which reliably transmits the data at a high rate.




BACKGROUND OF THE INVENTION




Communications cabling systems transmit information or data in the form of analog or digital electrical signals to and from various offices or workstations. Such cabling systems communicate between a distribution block or a patch panel located in a computer room or telecommunication closet and telecommunication devices located at the workstations, including telephones, facsimile machines and computers. Traditional cabling systems often comprise individual cables that extend uninterrupted from the wiring closet to the user devices (known as a “home run” cabling system). More recently, however, it has become increasingly popular to provide cabling systems with at least one connection point located intermediate the closet and the user devices (known as a “modular” cabling system). A modular cabling system has the advantage in that moves, adds, and changes to the cabling system are substantially simplified in that there is no need to reconfigure the cables all the way back to the wiring closet. Instead, only the cables “downstream” of the intermediate connection point need be reconfigured. Despite the increasing popularity of modular cable systems, however, such modular cabling systems have several drawbacks.




One drawback with existing modular cabling systems is that they can be difficult or confusing for unskilled or inexperienced workers to install properly. This problem can be exacerbated when the modular cabling systems includes what will herein be referred to as Y-cable assemblies, which are another recent development. Each Y-cable assembly includes wiring for multiple offices or workstations and includes three connectors: one upstream connector, one downstream (or pass-thru) connector, and one extractor (or peel-off) connector. The upstream and downstream connectors of the Y-cables can be interconnected to one another to provide a segmented (or serially connected) cabling system that includes all the wiring necessary for the individual offices or workstations. Each Y-cable assembly in the serial chain extracts a unique subset of the wires (or a circuit) to its extractor connector for use by one particular office or workstation. Thus, it is important for the installer to be able easily distinguish the different Y-cables because each can be used only once in the same serial chain.




However, in prior art segmented cabling systems the unique Y-cables have been distinguished only by a part number, usually stamped on one of the connectors. This makes it difficult for the installer to ensure that the system is configured correctly, e.g., the part numbers must be either memorized or written down before comparing one Y-cable with another. Moreover, performing moves, adds or changes on an existing system is further complicated in that such part numbers are located on portions of the connectors that are not visible when the Y-cables are installed. As a result, the installer must either uninstall (at least partially) each of the Y-cables for purposes of identification, or the written records (if they exist) of the wiring scheme must be located and consulted.




Another drawback with existing modular cabling systems is that, although the cables may be capable of communicating at Category 5 or higher performance levels, the connectors often form weak points that limit the overall capabilities of the system. In particular, cross-talk, which is a measure of the amount of signal coupling occurring between different pairs of wires either in a cable or cable-to-cable, can be a problem in connectors when the electrical pins extend close to one another and in parallel. Such cross-talk is a source of interference that degrades the ability of the system to transmit or receive signals, and can become particularly acute at high speeds. It has been discovered, however, that terminating the wire pairs at pin positions so as to leave empty (or unused) pins between the wire pairs can reduce this cross-talk in the connectors, which enables higher data transmission speeds. Nevertheless, with the continuing demand for even faster data transmission rates, there remains a need for cable assemblies that offer reduced cross-talk at even high transmission rates (e.g., 100 MHz to 300 MHz).




Modular segmented cabling systems similar to the type contemplated herein are shown in co-pending and commonly assigned U.S. patent application No. 09/163,886, filed Sep. 30, 1998, now U.S. Pat. No. 6,168,458 (“the '886 application”). The '886 application shows a preferred embodiment of a modular cabling system for providing high speed data communication to a cluster of eight workstations. The segmented cabling system shown in the '886 application includes a unique color coding scheme that enables an installer to properly configure the system by following a few easy to remember rules. Moreover, the '886 application also discloses a device for reducing cross-talk in the connectors.




Workstations conventionally include a variety of equipment besides computers, many of which do not communicate at the same high speeds as modern day computers. For example, telephones, facsimile machines, and modems operate quite well on cabling capable of transmitting signals at lower speeds, such as Category 3. Moreover, most equipment of these types require only one or two wire pairs for communication, rather than four as with computers. Providing transmission capability for such equipment, therefore, either requires that a separate low speed cabling network must be installed or, alternatively, that some of the cabling designed for high speed transmission be used for lower speed transmission.




Accordingly, it would be desirable to provide a single modular cabling system that can be easily installed to provide not only high speed communications for computers, but also low-speed communications for other types of equipment. Moreover, it would also be desirable to provide such a system using integrated connectors that pass both types of signals because this would reduce connector congestion and simplify installation.




SUMMARY OF THE INVENTION




The present invention relates to a modular communications cable assembly comprising a first connector and a second connector, each having an elongated array of electrical contacts. A first plurality of wires arranged in twisted pairs is terminated to selected electrical contacts in each array in a predetermined pattern such that at least one electrical contact remains unterminated between adjacent pairs of the first plurality of wires to reduce cross-talk therebetween. In addition, a second plurality of wires arranged in twisted pairs is terminated to selected electrical contacts in each array in the predetermined pattern such that no electrical contact remains unterminated between at least some adjacent pairs of the second plurality of wires.




The present invention also relates to a modular communications cable assembly for providing a plurality of communication circuits to a cluster of workstations. The cable assembly comprises an upstream connector, at least one downstream connector, a plurality of high-speed cable segments, and at least one low-speed cable segment. Each high-speed cable segment contains a set of twisted wire pairs for high-speed communication and extends between the upstream connector and one of the at least one downstream connectors. The at least one low-speed cable segment extends between the upstream connector and one of the at least one downstream connectors. The at least one low-speed cable segment provides a plurality of sets of twisted wire pairs for low-speed communication. Each circuit comprises one set of twisted wire pairs from the high-speed cable segments and one set of twisted wire pairs from the at least one low-speed cable segment




The present invention further relates to a wiring arrangement for providing a plurality of communication circuits to a cluster of workstations. The wiring arrangement includes at least one modular cable assembly having a set of wires extending between a pair of connectors. The set of wires is grouped into disjoint wiring subsets that define the plurality of circuits. The wiring arrangement comprises a breakout assembly for linking the plurality of circuits to the cluster of workstations. The breakout assembly includes a body, an in-feed connector, and a plurality of breakout connectors associated with the in-feed connector. The breakout assembly also includes communications wiring connecting the in-feed connector with the associated breakout connectors such that each circuit is diverted from the in-feed connector to one of the associated breakout connectors.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a schematic illustration showing an exemplary cable system of the present invention including two cable subsystems installed to provide communications to a cluster of six workstations.





FIG. 2

is a schematic illustration showing a first one of the cable subsystems of

FIG. 1

in greater detail.





FIG. 3

is a perspective view showing a first type of cable assembly with a first connector and a second type of cable assembly with a second connector, each cable assembly including a plurality of cable segments and the connectors configured to mate with each other.





FIG. 4A

is a perspective view of a first cable segment of the first cable assembly of

FIG. 3

with portions removed for purposes of illustration.





FIG. 4B

is a perspective view of a second cable segment of the first cable assembly of

FIG. 3

with portions removed for purposes of illustration.





FIG. 5

is a fragmentary sectional view of the first and second connectors of the first and second cable assemblies of

FIG. 3

interconnected.





FIG. 6

is a front elevational view of the first connector and cable assembly of FIG.


3


.





FIG. 7

is a top plan view of the first connector and cable assembly of

FIG. 3

with portions of the connector removed for purposes of illustration.





FIG. 8

is a sectional view of the first connector and cable assembly of

FIG. 3

taken along lines


8





8


in FIG.


7


.





FIG. 9

is a sectional view of the first connector and cable assembly of

FIG. 3

taken along lines


9





9


in FIG.


8


.





FIG. 10

is a schematic illustration showing a preferred termination pattern for defining three circuits of wires in the first connector and cable assembly of FIG.


3


.





FIG. 11

is a front elevational view of a third connector of the second cable assembly of FIG.


3


.





FIG. 12

is a top plan view of the third connector of the second cable assembly of FIG.


3


.





FIG. 13

is a schematic illustration showing an exemplary circuit breakout assembly that can be used in combination with the cable assemblies of

FIG. 3

to further increase the modularity of the cable system.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS





FIG. 1

is a schematic view of an exemplary cabling system


10


installed to provide communications to a cluster of six workstations


12


,


14


,


16


,


18


,


20


, and


22


divided by partitions


26


and


28


. Cabling system


10


includes a horizontal distribution cable (HDC)


32


, a consolidation point


34


, and cable subsystems


36


and


38


. HDC


32


is typically the longest cable in the system and extends from a main distribution interface or other modular closet interface device located in a computer room or wiring closet


33


to consolidation point


34


. As conventionally known, the distribution interface represents the demarcation point between the local telephone company or wide area network and the owner of the office distribution network. As is known in the art, HDC


32


may extend through the floor, ceiling, column of the building, or other structure depending on the layout of the building and the locations of wiring closet


33


and consolidation point


34


.




HDC


32


is for the most part a conventionally-known cable including electrical leads or wires extending in multiple, i.e., including sets of wires for two or more workstations. HDC


32


differs from a conventional horizontal distribution cable, however, in that it preferably is preterminated at both ends by connectors


30


of the same gender (preferably male). For reasons explained below, both connectors


30


are preferably of the same color, such as black. Because HDC


32


is not gender specific, an installer can pull HDC


32


from closet


33


out to the workstation area (or from the workstation area to the closet) without regard to whether the cable is left handed or right handed. Thus, unlike with gender specific cables, it is impossible for the installer to make a mistake by pulling the wrong end of HDC


32


, and thus no effort is ever wasted. Moreover, wasted effort from such a mistake can be substantial because pulling the horizontal distribution cables is often the most labor intensive part of the installation (e.g., an installer might spend several days to pull 50 cables 200 feet).




Consolidation point


34


, also known as a subsidiary distribution point, comprises a device for interconnecting wiring extending from closet


33


with wiring extending to the cluster of workstations. More precisely, consolidation point


34


comprises an organizer bracket located between HDC


32


and cable subsystems


36


and


38


, and may be situated at a conventional location such as in a ceiling, floor, or building support. Alternatively, consolidation point


34


may be located in one of the partitions


26


,


28


, in a furniture item, or in an external cabinet located adjacent to or mounted on one of the partitions. Consolidation point


34


eliminates the need to extend individual cable lengths all the way from the distribution interface at closet


33


to each individual workstation. As will be appreciated, cabling system


10


may include as many additional consolidation points as desired.




Cable subsystems


36


and


38


are modular in nature and provide telecommunications from consolidation point


34


to each of the workstations


12


-


22


in the cluster. Since cable subsystem


36


and


38


are substantially identical to one another, for purposes of brevity, only cable subsystem


36


is discussed hereafter.




Referring now to

FIG. 2

, cable subsystem


36


generally includes a feeder cable


40


(also known as an X-cable assembly) and a plurality of breakout or diversion cable assemblies


42


,


44


and


46


(also known as Y-cable assemblies). X-cable


40


is modular in nature and includes a plurality of data wires


54


(see

FIG. 4A

) and a plurality of voice wires


56


(see FIG.


4


B), all of which extend between an upstream connector


50


and a downstream connector


52


. For reasons explained below, connectors


50


and


52


are preferably of opposite gender and distinctly colored (preferably a red male connector and a black female connector, respectively). Upstream connector


50


of X-cable


40


is removably connectable to consolidation point


34


, and downstream connector


52


is removably connectable to Y-cable


42


. Additional or alternatively X-cables


40


could of course be located further downstream, such as between Y-cables


44


and


46


, to extend the length of cable subsystem


36


.





FIGS. 3-5

illustrate portions of X-cable


40


and Y-cable


42


. In particular,

FIG. 3

illustrates a downstream end portion of X-cable


40


terminated by connector


52


, and an upstream portion of Y-cable


42


. As can be seen, X-cable


40


includes an optional outer sheath


58


that encases four cable segments


1


,


2


,


3


,


4


(as indicated by the dashed lead-line, cable segment


1


is not visible in FIG.


3


). When sheath


58


is present, it preferably comprises a polymeric flame-retardant sheath that is shielded to prevent noise interference with cable segments


1


,


2


,


3


and


4


from induced voltage.





FIG. 4A

illustrates cable segment


1


of X-cable


40


in greater detail, with portions of the segment removed for clarity. As can be seen, cable segment


1


includes eight individually insulated wires


54


that are arranged as four twisted pairs and enclosed within a sheath


60


. Sheath


60


may be a polymeric flame-retardant sheath and/or shielded to prevent induced voltage. Cable segments


2


and


3


are substantially identical to cable segment


1


. In the preferred embodiment, cable segments


1


,


2


and


3


each include wires


54


designed to carry high-speed data signals (e.g., Category 5 or higher)





FIG. 4B

illustrates cable segment


4


of X-cable


40


in greater detail, with portions of the segment removed for clarity. As can be seen, cable segment


4


includes twelve individually insulated wires


56


that are arranged as six twisted pairs and enclosed within a sheath


62


. Sheath


62


may be a polymeric flame-retardant sheath and/or shielded to prevent induced voltage. In the preferred embodiment, cable segment


4


includes wires


56


designed to carry low-speed voice signals (e.g., Category 3 to Category 5). Those skilled in the art will recognize that wires


56


could also carry low-speed data signals. Moreover, it should be clear that the terms “low-speed” and “high-speed” are used in a relative sense. That is, as connector and cabling technology improves and the speeds increase, the high-speed cabling transmission speeds could be, for example, Category 7-9, while the low-speed cabling transmission speeds could be Category 5-6.




Returning to

FIG. 3

, downstream connector


52


of X-cable


40


comprises a body


64


having a male mating portion


66


that includes a plurality of electrical contacts


68


spaced along opposite side walls of a terminal bar


70


. The individual wires


54


,


56


of cable segments


1


,


2


,


3


and


4


are electrically connected (or terminated) to selected electrical contacts


68


of connector


52


in a predetermined pattern designed to reduce cross-talk in the connector, as explained below. Similarly, the individual wires


54


,


56


are also terminated to selected electrical contacts at upstream connector


50


of X-cable


40


, but in a complimentary or opposite pattern.





FIGS. 6-9

illustrate connector


52


and the predetermined termination pattern in greater detail. As best seen in

FIG. 6

, connector


52


is a conventional 50-pin (25 pair) connector in which electrical contacts


68


are arranged in two parallel rows of 25 pins each, numbered


1


-


25


in one row and


26


-


50


in the other row. Pin position


1


is adjacent to pin position


26


at one end of connector


52


, and pin position


25


is adjacent to pin position


50


at the other end. Each electrical contact


68


includes a rearwardly facing insulation displacement portion


71


and a forwardly facing contact portion


72


. Each insulation displacement portion


71


includes one wire receiving socket


74


, which is sized to cut through the wire insulation of one wire


54


or


56


inserted therein to electrically interconnect the wire


54


or


56


with electrical contact


68


.




As discussed above, wires


54


and


56


of cable segments


1


,


2


,


3


and


4


are positioned in specific sockets


74


of connector


52


in a predetermined pattern designed to reduce cross-talk. In particular, wires


54


of each twisted pair in data cable segments


1


,


2


, and


3


are inserted into adjacent sockets


74


such that at least one socket


74


is skipped (i.e., left empty) between the adjacent twisted pairs. This termination pattern provides extra spacing between the adjacent pairs used for high speed data transmission, which has been found to reduce cross-talk and thus enable higher speeds. As for wires


56


of voice cable segment


4


, such extra spacing is not required between the adjacent pairs because the communication speeds of such devices are generally low enough that cross-talk is not a problem. Thus, it is possible to utilize a more dense termination pattern for wires


56


, which in turn allows better space utilization in connector


52


. For example, in the preferred embodiment which utilizes three data cable segments


1


,


2


and


3


, a termination pattern that also provides three voice twisted pairs (one for each data cable segment) would be particularly desirable because most workstation users require one data and one voice outlet. This balancing of data and voice capacity can be achieved in a 50-pin connector by terminating all twelve wires


56


(or six pairs) of voice cable segment


4


in adjacent sockets


74


at one end of connector


52


such that no sockets


74


are skipped between voice wires


56


. However, one socket


74


is preferably left empty between voice wires


56


and data wires


54


to prevent induced cross-talk.




Although a number of termination patterns could be devised to meet the above requirements, one preferred arrangement will now be described with reference to

FIGS. 7-9

. As can be seen, data cable segment


1


includes eight wires


54


arranged as four twisted pairs (


54


A,


54


B), (


54


C,


54


D), (


54


E,


54


F), (


54


G,


54


H), which are assigned to specific sockets


74


of connector


52


. In particular, wires


54


A and


54


B are assigned to respective pin positions


2


and


3


, wires


54


C and


54


D are assigned to respective pin positions


5


and


6


, wires


54


E and


54


F are assigned to respective pin positions


27


and


28


, and wires


54


G and


54


H are assigned to respective pin positions


30


and


31


. Thus, the four twisted pairs of data cable segment


1


are assigned to pin positions


2


-


3


,


5


-


6


,


27


-


28


, and


30


-


31


, while pin positions


1


,


4


,


26


and


29


are skipped. Data cable segments


2


and


3


each include eight wires arranged as four twisted pairs, which are assigned to specific sockets


74


of connector


52


in similar termination patterns. In particular, the four twisted pairs of cable segment


2


are assigned to pin positions


8


-


9


,


11


-


12


,


33


-


34


, and


36


-


67


, while pin positions


7


,


10


,


32


and


35


are skipped. Similarly, the four twisted pairs of cable segment


3


are assigned to pin positions


14


-


15


,


17


-


18


,


39


-


40


, and


42


-


43


, while pin positions


13


,


16


,


38


and


41


are skipped.




Voice cable segment


4


includes twelve wires


56


arranged as six twisted pairs: three of which pairs (


56


A,


56


B), (


56


C,


56


D), (


56


E,


56


F) are assigned to sockets


74


along the upper row of pins in connector


52


in FIG.


8


and three of which pairs (


56


G,


56


H), (


56


I,


56


J), (


56


K,


56


L) are assigned to sockets


74


along the lower row of pins in connector


52


in FIG.


8


. From the combination of

FIGS. 8 and 10

, it can be seen that four of the six twisted pairs-namely, pairs (


56


A,


56


B), (


56


C,


56


D), (


56


G,


56


H) and (


56


I,


56


J)—are assigned to respective pin positions


20


-


21


,


23


-


24


,


45


-


46


, and


48


-


49


in a pattern similar to the pattern in which the four twisted pairs in each of the data cable segments


1


,


2


and


3


are terminated. However, unlike with those data termination patterns, the remaining pin positions between these four voice pairs, i.e., pin positions


22


,


25


,


47


and


50


, are not skipped. Instead, they are utilized for terminating the remaining two twisted pairs of voice wires


56


—i.e., pairs (


56


E,


56


F) and (


56


K,


56


L). In particular, one of the remaining twisted pairs is assigned to pin positions


22


and


25


, and the other is assigned to pin positions


47


and


50


. As already mentioned, pin positions


19


and


44


, i.e., the pin positions between data wires


54


and voice wires


56


, are preferably left empty to provide increased spacing and thereby reduce cross-talk.




Terminating four of the six voice twisted pairs in the same pattern as is used for each of the four data twisted pairs provides several advantages. For example, the manufacture of the cable assemblies is simplified because the worker can connect the voice wires in the same pattern as the data wires, with the only difference being the extra step of terminating the two remaining voice wires. More importantly, however, this pattern also facilitates backwards compatibility with other cabling systems of the assignee that pass four high-speed data cable segments through a 50-pin connector. One such system is disclosed in co-pending and commonly assigned U.S. patent application No. 09/163,886, filed Sep. 30, 1998, now U.S. Pat. No. 6,168,458, the entire contents of which are hereby incorporated by reference.





FIG. 10

shows a schematic representation of a preferred termination pattern superimposed on connector


52


(illustrated as a male 50-pin connector), and also defines three workstation circuits


1


,


2


and


3


comprising disjoint sets of wires (i.e., no wires in common) extending throughout all cable assemblies


40


,


42


,


44


and


46


in cable subsystem


36


. As is conventional, the upper row of pin positions is numbered


1


-


25


from left to right, and the lower row of pin positions is numbered


26


-


50


from left to right. The symbol “x” denotes pin positions that are skipped, and the numerals “


1


”, “


2


” and “


3


” denote pin positions that are utilized for circuits


1


,


2


and


3


, respectively. As mentioned above, each circuit


1


,


2


and


3


utilizes four twisted pairs of wires


54


for high-speed data transmission and two twisted pairs of wires


56


for low-speed voice communication. In particular, circuit


1


utilizes pin positions


2


-


3


,


5


-


6


,


27


-


28


and


30


-


31


for the four data twisted pairs and pin positions


20


-


21


and


23


-


24


for the two voice twisted pairs. Circuit


2


utilizes pin positions


8


-


9


,


11


-


12


,


33


-


34


and


36


-


37


for the four data twisted pairs and pin positions


45


-


46


and


48


-


49


for the two voice twisted pairs. Finally, circuit


3


utilizes pin positions


14


-


15


,


17


-


18


,


39


-


40


and


42


-


43


for the four data twisted pairs and pin positions


22


,


25


and


47


,


50


for the two twisted pairs.




Thus, it can be seen that the two wires


54


of each data twisted pair are terminated to adjacent pin positions in a row with one empty pin between each pair, that wires


56


of the voice twisted pairs are terminated to pin positions without leaving any empty pins, and that one pin is skipped between the data twisted pairs the voice twisted pairs. It should be clear that a number of termination patterns could meet these requirements, and that the above-described and illustrated wire termination pattern is merely one presently preferred pattern.




As further shown by

FIGS. 7 and 8

, connector


52


preferably includes a device


76


for further reducing cross-talk among data wires


54


. As illustrated, cross-talk reduction device


76


includes a body


78


and an electrically conductive member


80


. Body


78


is preferably made of a plastic, nonconductive material, but it may be formed from a variety of other materials including conductive ones.




Electrically conductive member


80


electrically interconnects empty sockets


74


to each other in connector


52


. In the illustrated embodiment, therefore, conductive member


80


electrically interconnects empty sockets


74


corresponding to pin positions


1


,


4


,


5


,


10


,


13


,


16


and


19


along one row of electrical contacts


68


, and pin positions


26


,


29


,


32


,


35


,


38


,


41


and


44


along the other row. The empty pin positions in the two rows may also be electrically interconnected with each other if desired. As illustrated, conductive member


80


includes a plurality of pins


82


that are located and sized such that pins


82


extend into and become firmly seated in associated sockets


74


when device


76


is installed on connector


52


. Cross-talk reduction device


76


could be part of the initial manufacture of connector


52


or, alternatively, it could be retrofitted onto an existing connector


52


and then soldered, glued, or otherwise held in place (e.g., by simple interference or snap fit). Even simpler, cross-talk reduction device


76


could comprise a plurality of short segments of electrical wiring that would be inserted into empty sockets


74


of electrical contacts


68


to interconnect them.




Since electrically conductive member


80


is made of a highly conductive material, such as copper, it absorbs and distributes energy that leaks from the pairs and which would otherwise be transferred directly to an adjacent wire pair. Device


76


also reduces alien cross-talk, which is the tendency of signals in one cable segment to induce signals in adjacent cable segment when connected in series. U.S. patent application No. 09/163,886, now U.S. Pat. No. 6,168,458, which was incorporated by reference above, includes a table that illustrates comparative test results for similar connectors both with and without cross-talk reduction devices. As can be seen from the table, cross-talk reduction device


76


allows electronic signals or data to be transmitted at faster rates than would otherwise be possible. In particular, appropriately configured devices can be used to reduce cross-talk such that connectors designed originally for Cat 5 performance (100 Mbps) can be improved to Cat 6, Cat 7, or even higher.




Although the above-described termination pattern and cross-talk reduction device


76


have been illustrated and described for reducing cross-talk in a 50-pin male connector (i.e., connector


52


in X-cable


40


), such cross-talk reducing features are also preferably used in all the other connectors in cable subsystem


36


, regardless whether male or female, upstream or downstream, or the number of pins or rows of electrical contacts.




Returning now to

FIG. 2

, each Y-cable


42


,


44


and


46


generally includes an upstream connector


84


(preferably female), a pass-thru connector


86


(preferably male), a peel-off connector


88


, and a plurality of data and voice wires


90


and


92


, respectively (see FIG.


3


). For reasons explained below, it is also preferable for connectors


84


and


86


to be differently colored (preferably red and black, respectively). Preferably, pass-thru and peel-off connectors


86


and


88


, respectively, of Y-cables


42


,


44


and


46


are all similar in construction to downstream connector


52


of X-cable


40


described above.




As best illustrated in

FIG. 3

, upstream connector


84


of Y-cable


42


comprises a body


94


having a female mating portion


96


, which includes a plurality of electrical contacts


98


spaced along opposed side walls of a slot


100


. A portion of electrical contacts


98


of upstream connector


84


are electrically connected to individual wires


90


,


92


of cable segments


1


,


2


,


3


and


4


in a predetermined pattern that is similar to, but opposite, that described above for downstream connector


52


of X-cable


40


. This is necessary so that the wires


54


,


56


of cable segments


1


,


2


,


3


and


4


in X-cable


40


are electrically connected to appropriate wires


90


,


92


of associated cable segments


1


,


2


,


3


and


4


in Y-cable


42


when connectors


52


and


84


are interconnected. As best seen in

FIG. 5

, Y-cable assembly


42


can be serially interconnected with X-cable


40


by inserting terminal bar


70


of downstream connector


52


into slot


100


of upstream connector


84


, which causes electrical contacts


68


to firmly engage electrical contacts


98


. Y-cables


42


,


44


and


46


can be serially interconnected to one another in a similar manner.




Returning again to

FIG. 2

, each Y-cable


42


,


44


and


46


is uniquely configured to divert a unique subset of wires


90


,


92


(i.e., circuit


1


,


2


or


3


) from upstream connector


84


to peel-off connector


88


, while the remaining wires


90


,


92


continue on from upstream connector


84


to pass-thru connector


86


. In particular, Y-cable


42


is configured such that wires


90


,


92


of circuit


1


(see

FIG. 10

) extend through an extraction lead


102


to peel-off connector


88


, while wires


90


,


92


of circuits


2


and


3


continue on through a main lead


104


to pass-thru connector


86


. Y-cable


44


is configured such that wires


90


,


92


of circuit


2


(see

FIG. 10

) extend through extraction lead


102


to peel-off connector


88


, while wires


90


,


92


of circuits


1


and


3


continue on through main lead


104


to pass-thru connector


86


. And Y-cable


44


is configured such that wires


90


,


92


of circuit


3


(see

FIG. 10

) extend through extraction lead


102


to peel-off connector


88


, while wires


90


,


92


of circuits


1


and


3


continue on through main lead


104


to pass-thru connector


86


.




Accordingly, Y-cables


42


,


44


and


46


can be serially interconnected to provide integrated data and voice circuits


1


,


2


and


3


to a cluster of workstations, with particular circuits


1


,


2


and


3


being diverted to individual workstations for use by both high-speed and low-speed telecommunication devices. Moreover, because each Y-cable


42


,


44


and


46


includes all three unique subsets


1


,


2


and


3


of wires


90


,


92


, either in main lead


104


or extraction lead


102


, the Y-cables


42


,


44


and


46


can be connected in any order and still function.




An example will help make this more clear. Referring again to

FIG. 2

, X-cable


40


can be seen to carry electrical signals A, B and C through respective wire subsets (or circuits)


1


,


2


and


3


to and from Y-cable


42


. Y-cable


42


diverts circuit


1


, and thus signal A, through extraction lead


102


to peel-off connector


88


for use in workstation


12


(WS




12




). Signals B and C, however, continue through main lead


104


via circuits


2


and


3


to pass-thru connector


86


, and thus to upstream connector


84


of Y-cable


44


. Y-cable


44


in turn diverts circuit


2


, and thus signal B, through extraction lead


102


to peel-off connector


88


for use in workstation


14


(WS




14




), while signal C continues through main lead


104


via circuit


3


to pass-thru connector


86


, and thus to upstream connector


84


of Y-cable


46


. Lastly, Y-cable


46


diverts circuit


3


, and thus signal C, to peel-off connector


88


for use in workstation


16


(WS




16




).




As further shown by

FIG. 2

, each unique Y-cable


42


,


44


and


46


includes a unique indicium corresponding to the unique wire subset


1


,


2


or


3


included in its extraction lead


102


. In a preferred embodiment, the indicium associated with each Y-cable


42


,


44


and


46


is a unique color, which preferably is located on each peel-off connector


88


and/or on the outer sheath of extraction lead


102


. For example, Y-cable


42


, in which wire subset


1


is diverted by extraction lead


102


, includes a blue peel-off connector


88


and a blue extraction lead


102


. Likewise, peel-off connectors


88


of Y-cables


44


and


46


are white and gray, respectively, to correspond with respective wire subsets


2


and


3


being diverted by extraction leads


102


. The unique color indicium is preferably applied to each peel-off connector


88


by molding it from an appropriately colored molding material. Alternatively, peel-off connector


88


may have a colored coating or paint applied thereto, or a colored member (e.g., a sticker) may be adhered to the connector, either during or after initial manufacture.




From the foregoing, it is clear that cable subsystem


36


includes unique color assignments that would enable an installer to easily distinguish the unique Y-cables


42


,


44


and


46


from one another, simply by a glance. Thus, even an inexperienced worker can easily install the system or perform moves, adds or changes, in substantially less time and with reduced chance for errors than was possible using the heretofore known modular cabling systems. Moreover, the installer need only remember and follow a few simple rules to properly connect the Y-cables in a properly functioning serial chain: a red connector is always connected to a black connector, and each unique color (e.g., blue, white, gray) can be used only once in the chain. However, Y-cables


42


,


44


and


46


may be interconnected in any order. Consequently, this unique color-coding scheme makes installation of a segmented modular cabling system simple and non-threatening.





FIGS. 11 and 12

illustrate peel-off connector


88


of Y-cable


42


in greater detail. As can be seen, connector


88


is similar to downstream connector


52


of X-cable


40


, and includes a body


106


and a plurality of electrical contacts


108


. Connector


88


is preferably adapted for being installed in a port


110


form in one of the partitions


26


,


28


such that a front face


112


of connector


88


remains visually accessible even when installed (see FIG.


12


). To secure connector


88


in place, body


106


preferably includes a pair of lateral projections


113


that extend from opposite ends of body


106


and contain screw or bolt holes


114


. Body


106


includes a front mating portion of a predetermined gender (preferably male) that is configured for mating with a patch cable (such as described below) having a connector of opposite gender.




In the exemplary embodiment, the unique indicium on each peel-off connector


88


is preferably located on front face


112


and extensions


113


. Thus, the installer can easily determine which Y-cables


42


,


44


and


46


are currently being used in cable subsystem


36


without having to remove or disturb any of the peel-off connectors


88


from the ports


110


. Of course, alternative or additional easily distinguishable unique indicia could be used to achieve this same result. For example, front face


112


of each connector


88


could be provided with a unique surface texture. Unique surface texture indicia would enable the installer to easily identify and distinguish the Y-cables


42


,


44


and


46


from one another even when connectors


88


are, for some reason, not visible. For example, surface texture indicia would be highly advantageous when the lighting is poor, or when there are other visual impairments such as furniture or other obstructions that block the installer's view. It should thus be clear that the only requirements for the unique indicia are that they enable easy identification of the various assemblies and remain accessible (e.g., visually or tactilely) even when connectors


88


are installed.




Referring now to

FIG. 12

, the preferred pattern for terminating the wires


90


,


92


of circuits


1


,


2


and


3


in peel-off connectors


88


of respective Y-cables


42


,


44


, and


46


will be explained. In the illustrated embodiment, each extraction lead


102


comprises all four pairs of wires


90


from one of the data cable segments


1


,


2


,


3


as well as two pairs of wires


92


from voice cable segment


4


. However, no matter which circuit


1


,


2


or


3


is being diverted to peel-off connector


88


, the eight data wires


56


(four pairs) and four voice wires (two pairs) are preferably terminated to identical pin positions in the connector. In particular, the eight data wires


90


(four pairs) are preferably terminated to pin positions in the same manner as explained above for terminating data wires


54


of cable segment


1


in downstream connector


52


of X-cable


40


(see

FIGS. 7

,


8


). That is, the four pairs of data wires


90


of circuit


1


are preferably terminated in pin positions


2


-


3


,


5


-


6


,


27


-


28


, and


30


-


31


. As to the four voice wires


92


, one pair is preferably terminated in pin positions


20


-


21


, and the other pair is preferably terminated in pin positions


23


-


24


.




Terminating data and voice wires


90


,


92


of all three circuits


1


,


2


and


3


to the same pin positions in peel-off connector


88


for all three Y-cables


42


,


44


and


46


provides a number of advantages. Most importantly, the same type of patch cable can be used to carry the signals from peel-off connector


88


to the user devices, no matter which Y-cable


42


,


44


or


46


is being used. Although not illustrated, such a patch cable would have an upstream connector configured to releasibly mate with peel-off connector


88


and one or more downstream connectors configured to releasibly mate with the user devices. For example, the downstream connector(s) of the patch cable could comprise a single 50-pin connector or, alternatively, one four-pair RJ45 data plug for a computer and one two-pair RJ11 plug for a telephone, modem or fax. Another possibility is that the patch cable could be provided with three downstream connectors comprising a four-pair RJ45 plug for the computer, a one-pair RJ11 plug for the telephone, and a one-pair RJ11 plug for the modem. It will be recognized that other combinations are possible, such as breaking the one four-pair data into two separate two-pairs.





FIG. 13

shows a schematic representation of a breakout box


116


that can be used in combination with the above-described cabling system


10


to further increase its modularity. In the illustrated embodiment, breakout box


116


comprises two in-feed connectors


118


and six associated breakout connectors


120


,


122


and


124


. In addition, breakout box


116


includes two input connectors


126


, each of which is associated with an output connector


128


. All connectors


118


-


128


are preferably mounted on a front face


130


of a housing


132


or, alternatively, on a plate, rack, or bracket. Preferably, housing


132


is generally rectangular in shape and configured for mounting inside one of the partitions


26


,


28


.




Preferably, connectors


126


,


128


provide a straight passthrough capability, while connectors


118


-


124


provide a circuit breakout capability. The circuit passthrough capability (i.e., a one-to-one coupling) is provided by internal cabling


134


, which electrically couples each input connector


126


to one associated output connector


128


. In particular, internal cabling


134


is terminated to input and output connectors


126


and


128


, respectively, in the same pattern as discussed above for the upstream and downstream connectors


50


and


52


, respectively, of X-cable


40


.




The circuit breakout capability (i.e., a one-to-three coupling) is provided by internal cabling


136


,


138


and


140


, which electrically couples each in-feed connector


118


to three associated breakout connectors


120


,


122


and


124


, respectively. Internal cabling


136


,


138


and


140


is terminated to in-feed connector


118


in the same pattern as described above for upstream connector


84


of Y-cables


42


,


44


and


46


, and also terminated to breakout connectors


120


,


122


and


124


in the same pattern as described above for peel-off connectors


88


of Y-cables


42


,


44


and


46


. Thus, the three circuits


1


,


2


and


3


present at in-feed connector


118


are diverted such that circuit


1


goes through cabling


136


to breakout connector


120


, circuit


2


goes through cabling


138


to breakout connector


120


, and circuit


3


goes through cabling


138


to breakout connector


124


.




One of skill in the art will recognize that breakout box


116


could be utilized either in place of, or in addition to, consolidation point


34


to increase the modularity of cabling system


10


. For example, breakout box


116


could be installed in one partition wall


26


,


28


such that front face


130


is exposed in a workstation for use by a single heavy-duty user (e.g., a user requiring three data outlets and three voice outlets). This arrangement would allow the heavy-duty user access to all three circuits


1


,


2


and


3


at one convenient location, without having to breakout each of the circuits


1


,


2


and


3


by means of three serially connected Y-cables


42


,


44


and


46


.




Breakout box


116


could also be useful in other situations, such as illustrated by the following example. Assume that breakout box


116


is initially installed in partition panel


26


forming the left side of workstation


12


in

FIG. 1

, and that users at workstations


16


and


22


currently are provided one data and one voice outlet, and three data and three voice outlets, respectively. This capability could be initially provided through breakout box


116


, for example, by running an X-cable


40


from breakout connector


120


of breakout box


116


to an outlet at workstation


16


, and by running another X-cable


40


from output connector


128


to workstation


22


. If, at a later date, the users in workstations


16


and


22


needed to switch locations, each user could be provided with the required communication capability simply by swapping the upstream connectors of each X-cable


40


. Such a switch could not be just as easily made at consolidation point


34


, however, because swapping X-cables or Y-cables at that point would effect additional workstations not involved in the switch.




Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, although each cable assembly is illustrated and described as using 50-pin connectors each having two rows of 25 pins (i.e., a two dimensional array), connectors having electrical contacts in other arrangements could be used, e.g., a linear array (i.e., one dimensional), an M×N matrix, or even a circular array of electrical contacts. Moreover, connectors having increased pin capacity (e.g., 64-pin connectors each having two rows of 32 pins) could be used to allow the construction of Y-cable assemblies that extract more than one circuit to the peel-off connectors. These and other modifications are considered to form part of the invention, which is limited only by the scope of the claims which follow.



Claims
  • 1. A modular communications cable assembly, comprising:a first connector and a second connector, each connector having a rectangular array of electrical contacts including a first contiguous section of high-speed pins adjacent one end of the array and a second contiguous section of low-speed pins adjacent an opposite end of the array; a plurality of high-speed wires arranged as twisted pairs and extending between the first and second connectors, the high-speed wires being terminated to selected high-speed pins such that the wires of each twisted pair are terminated to adjacent high-speed pins and at least one high-speed pin is left empty between each adjacent pair of high-speed wire pairs; and a plurality of low-speed wires arranged as twisted pairs and extending between the first and second connectors, the low-speed wire being terminated to the low-speed pins such that no low-speed pins are left empty between the low-speed wire pairs.
  • 2. The cable assembly of claim 1, wherein the plurality of high-speed wires are used for high-speed communication and the plurality of low-speed wires are used for low-speed communication.
  • 3. The cable assembly of claim 1, wherein the plurality of high-speed wires are used for transmitting data signals and the plurality of low-speed wires are used for transmitting voice signals.
  • 4. The cable assembly of claim 1, wherein the plurality of high-speed wires and the plurality of low-speed wires are contained within separate cable segments.
  • 5. The cable assembly of claim 4, wherein the plurality of high-speed wires are contained within three separate cable segments, each cable segment including eight wires arranged as four twisted pairs and being encased by a separate protective sheath.
  • 6. The cable assembly of claim 4, wherein the plurality of low-speed wires are contained within a single cable segment encased by a protective sheath, which includes twelve wires arranged as six twisted pairs.
  • 7. The cable assembly of claim 1, wherein at least one electrical contact is left empty between the first and second contiguous sections of electrical contacts to reduce cross-talk therebetween.
  • 8. The cable assembly of claim 1, wherein each rectangular array includes two parallel rows of electrical contacts.
  • 9. The cable assembly of claim 8, wherein each row of electrical contacts includes 25 pins.
  • 10. The cable assembly of claim 1, further comprising:a third connector having a rectangular array of electrical contacts including a section of high-speed pins and a section of low-speed pins; a plurality of high-speed extraction wires arranged in twisted pairs and terminated to selected high-speed pins in the first and third connectors such that at least one high-speed pin is left empty between adjacent pairs of the high-speed extraction wires to reduce cross-talk therebetween; and a plurality of low-speed extraction wires arranged in at least one twisted pair and terminated to selected low-speed pins in the first and third connectors.
  • 11. The cable assembly of claim 10, wherein the plurality of high-speed extraction wires are used for data communication and the plurality of low-speed extraction wires are used for voice communication.
  • 12. A modular communications cable assembly, comprising:a first plurality of high-speed twisted wire pairs and a second plurality of low-speed twisted wire pairs, the first and second pluralities of twisted wire pairs extending between a pair of electrical connectors, each of the electrical connectors including a rectangular array of electrical contacts, the first plurality of high-speed twisted wire pairs being terminated to selected electrical contacts in a first contiguous region of electrical contacts adjacent one end of the rectangular array in each connector such that at least one electrical contact is left empty in the array between adjacent high-speed twisted wire pairs, and the second plurality of low-speed twisted wire pairs being terminated to electrical contacts in a second contiguous region of electrical contacts adjacent an opposite end of the rectangular array in each connector such that no electrical contacts are left empty in the array between adjacent low-speed twisted wire pairs.
  • 13. The cable assembly of claim 12, wherein at least one electrical contact is left empty between the first and second contiguous regions of electrical contacts to reduce cross-talk therebetween.
  • 14. The cable assembly of claim 12, further comprising a third electrical connector having a third rectangular array of electrical contacts and a plurality of high-speed and low-speed wires extending between one of the connectors from the pair of electrical connectors and the third connector, the high-speed and low-speed wires being terminated to electrical contacts in the third rectangular array in an identical pattern as used for terminating the high-speed and low-speed wires in the one of the connectors.
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