The present invention relates to a communication connector having first and second inserts in a plug housing to achieve the required levels of crosstalk. More particularly, the present invention relates to a communication connector having a second insert that abuts a cable sheath to control wire length between a cable sheath and the first insert, as well as maintaining wire separation and twist present in the cable sheath. Still more particularly, the present invention relates to a communication connector having an overmold to control crosstalk and to provide strain relief.
In telecommunication systems, signals are transmitted over cables having balanced twisted pairs of wires. Typical cables have four pairs of twisted wires in them. For connecting wires to other cables or to other apparatus, connectors are mounted on the ends of the cables. Although connectors can be mounted in the field after the cables and wires therein are cut to the appropriate length for the particular installation, preferably, high performance connectors are preferably assembled in a controlled environment so they can be tested and qualified for use.
Due to advances in telecommunications and data transmissions, connectors, particularly including plugs, have become a critical impediment to good performance of data transmission at new, higher frequencies. Some performance characteristics, particularly near end crosstalk and return loss, degrade beyond acceptable levels at these higher frequencies.
One way to overcome this crosstalk problem is to increase the spacing between the signal lines. Another method is to shield the individual signal lines. However, in many cases, the wiring is pre-existing and standards define geometries and pin definitions for connectors making such changes to those systems is cost prohibitive. In this specific situation of communications systems, using unshielded twisted pair wiring cables is the only practical alternative.
When electrical signals are carried on a signal line or wire which is in close proximity to another signal line or other signal lines, energy from one signal can be coupled onto adjacent signal lines by means of the electric field generated by the potential between the two signal lines and the magnetic field generated as a result of the changing electric fields. This coupling, whether capacitive or inductive, is called crosstalk when the coupling occurs between two or more signal lines. Crosstalk is a noise signal and degrades the signal-to-noise margin (s/n) of a system. In communications systems, reduced s/n margin results in greater error rates in the information conveyed on the signal lines.
Performance requirements for modular plugs are defined in ANSI/TIA/EIA-568-B, “Commercial Building Telecommunications Cabling Standard”. In the Category 6 Addendum TIA-568-B.2-1 to that standard, the acceptable performance ranges are detailed in Section E.3.2.2, and summarized in Table E.3.
Additionally, in communications systems certain standards have been developed that define connector geometry and pin out definitions. Those standards were created prior to the need for high speed data communications, and have created a large installed base of wiring connectors. Additionally, those standards have created a need for connectors capable of maintaining the requirements of higher speed communications, while maintaining compatibility with original connectors.
The standard connector geometry and pin outs can generate a great deal of crosstalk at higher signal frequencies. Connectors addressing this problem include U.S. Pat. No. 5,432,484 to Klas et al and U.S. Pat. No. 5,414,393 to Rose et al, the subject matters of which are hereby incorporated by reference in their entirety.
U.S. Pat. No. 6,080,007 to Milner et al., and which is hereby incorporated by reference in its entirety, discloses a connector for a communications system. However, the rear sled 34 (
U.S. Pat. No. 6,439,920 to Chen discloses an electronic connector for high speed transmission. The end of the cable sheath 30 (
In addition to the crosstalk reduction provided by the inventions of the above cited patents, crosstalk generated at the connection between the cable wires and the connectors, particularly the plug connectors has become significant. Variations in the placement of the wiring creates varying amounts of crosstalk. Additionally, the wires must be accurately and precisely located within the connector to facilitate termination by the insulation displacement contacts.
Thus, there is a continuing need to provide improved connectors for communications systems.
Accordingly, it is a primary objective of the present invention to provide an improved connector for a communications system.
A further objective of the present invention is to provide an improved connector for controlling the crosstalk level.
A still further objective of the present invention is to provide a connector for controlling the distance between the end of the cable sheath and the sled insert of the connector.
Still another objective of the present invention is to provide a connector for maintaining the separation and twist of the wires in the cable sheath between the cable sheath and the sled insert.
Another objective of the present invention is to provide a connector with an overmold to further control crosstalk levels and to provide strain relief for the cable.
The foregoing objectives are basically attained by a connector for a communications system that provides desired levels of crosstalk by controlling the positions and lengths of the wires, and a kit and method for forming the connector. The connector has a plug housing having front and rear ends. An internal chamber opens on the rear end of the plug housing and is defined by housing walls. A plurality of slots extend through one of the housing walls adjacent the front end and into the internal chamber. A plurality of insulation displacement contacts are mounted in the slots for movement between retracted positions spaced from the internal chamber and inserted positions extending into the internal chamber. A first insert is disposed in the internal chamber. The first insert has a front end proximal the front end of the plug housing. A first passageway extends from the front end of the first insert to the rear end of the first insert. A plurality of openings in a first insert wall adjacent the front end are aligned with the plurality of slots in the plug housing and extend into the first passageway. A second insert is partially disposed in the internal chamber and has a front end proximal the first insert rear end. The second insert has first, second, third and fourth channels extending from the rear end to the front end of the second insert. Four pairs of wires extend from a cable sheath. Each pair of wires pass through one of the first, second, third and fourth channels of the second insert and through the first passageway to the insulation displacement contacts in the internal chamber. The first and second inserts control the positioning and the length of the wires between the cable sheath and the insulation displacement contacts in the plug housing, thereby controlling the crosstalk levels.
Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the invention.
Referring now to the drawings that form a part of the original disclosure:
As shown in
A first insert 51 is disposed in the internal chamber 24. The first insert 51 has a front end 52 proximal the front end 22 of the plug housing 21. A first passageway 53 extends from the front end 52 of the first insert 51 to the rear end 54 of the first insert. A plurality of openings 57 in a first insert wall adjacent the front end 52 are aligned with the plurality of slots 31 in the plug housing and extend into the first passageway 53.
A second insert 61 is partially disposed in the internal chamber 24 and has a front end 62 proximal the first insert rear end 54. A rear end 63 of the second insert 61 extends beyond the plug housing rear end 23. The second insert 61 has first, second, third and fourth channels 65-68 (
Cable 71 carries four pairs of wires that extend from an end 73 of a cable sheath 72. Each pair of wires pass through one of the first, second, third and fourth channels 64-67 of the second insert 61 and through the first passageway 53 to the insulation displacement contacts 41 in the internal chamber 24. The first and second inserts 51 and 61 control the positioning and the length of the wires between the end 72 of the cable sheath 71 and the insulation displacement contacts 41 in the plug housing 21, thereby controlling the crosstalk levels.
The plug housing 21 has a front end 22 and a rear end 23, as shown in
The plurality of insulation displacement contacts 41 are mounted in the slots 31 for movement between retracted positions (
A first insert 51, or sled, as shown in
A second insert 61, or wire spacer, as shown in
A cable 71 carries four pairs 86-89 of wires 92-99 within a cable sheath 72, as shown in
Third insert 81, or wire spacer, as shown in
Preferably, the cable 71 carries four pairs of wires, as shown in
An overmold 121 may be used with the connector 111 according to a second embodiment of the present invention, as shown in
Preferably, the plug housing, first insert and second insert are made of a non-conductive material, such as a plastic material. Preferably, the plastic material is a dielectric material, such as a polycarbonate material.
The connector 11 according to a first embodiment of the present invention is shown unassembled in
Each of the four pairs of twisted wires emerging from the end 73 of the cable sheath 72 are maintained in their paired configuration. Preferably, two of the pairs of wires are untwisted for the length external of the cable sheath. However, these two pairs of wires may range from untwisted through varying degrees of twist external to the cable sheath depending on the desired level of crosstalk. The remaining two pairs of wires are maintained in their twisted configuration. The level of crosstalk is controlled by the degree of twist and shape of the wire pairs.
For example, in a typical Cat. 6 and 6e patch cord there are four pairs of wires within the cable. A first pair 86 is a twisted blue wire and a blue/white wire. A second pair 87 is a twisted orange wire and orange/white wire. A third pair 88 is a twisted green wire and a green/white wire. A fourth pair 89 is a twisted brown wire and a brown/white wire. The blue and blue/white wire pair and the green and green/white wire pair are untwisted along the length of wire extending beyond the end 73 of the cable sheath 72. The orange and orange/white pair and the brown and brown/white pair are maintained in their twisted configuration along the length of wire extending beyond the end 73 of the cable sheath 72.
Each pair of wires is then inserted into a separate channel 65-68 at the rear end 63 of the second insert 61. Preferably, the wires in the twisted configuration are placed in the outer channels 65 and 68. The wires in the untwisted configuration are placed in the inner channels 66 and 67. The second insert 61 is then slid down the length of the wires until the end 73 of the cable sheath abuts the shoulders 90 and 91 of the second insert. This controls the length of the wires from the end 73 of the cable sheath 72 to the first insert 51. For example, the twisted orange and orange/white wire pair is passed through channel 65. The untwisted green and green/white wire pair are passed through inner upper channel 66. The untwisted blue and blue/white wire pair are passed through inner lower channel 67. The twisted brown and brown/white wire pair are passed through outer channel 68. The two twisted pairs of wires are untwisted beyond the front end 62 of the second insert, but are twisted from the cable end 73 through the second insert 61. Preferably, the outer channels 65 and 68 and the lower inner channel 67 allow the three pairs of wires passing therethrough to be substantially parallel along the axial length of the second insert 61.
The positioning and spacing of the pairs of wires in the second insert controls coupling and crosstalk over the length of the second insert, thereby creating the desired amount of crosstalk. This is particularly facilitated by running the wire pairs in the inner upper and lower channels 66 and 67 in an untwisted manner to introduce the desired level of crosstalk, and by running the wire pairs in the outer channels 65 and 68 in a twisted manner to introduce a lesser amount of crosstalk between these pairs and the other pairs of wires. The dielectric material, length and wall thicknesses of the second insert further facilitate achieving the desired level of inductive and capacitive coupling to achieve the desired level of crosstalk.
The first insert 51 is then slid over the four pairs of wires extending beyond the front end 62 of the second insert so that the wires enter the passageway 51 of the first insert. The ramped portion 58 of the first insert 51 (
When the wires 92-99 reach the front end 52 of first insert 51, the wires are substantially linearly, or axially, arranged across the troughs 19A-19H of the front insert, i.e., the wires are substantially coplanar. Any portion of the wires extending beyond the front end 52 of the first insert 51 are cut off at the front end of the first insert. The first insert 51 is then inserted in the internal chamber 24 of the plug housing 21 until the front end 52 of the first insert abuts the front end 22 of the plug housing.
Insulation displacement contacts 41 may then be inserted from the insertion position of
The connector 121 according to a second embodiment of the present invention is shown assembled in
While advantageous embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention as defined in the appended claims.
This application is a division of U.S. patent application Ser. No. 10/753,770, filed Jan. 9, 2004.
Number | Date | Country | |
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Parent | 10753770 | Jan 2004 | US |
Child | 11598192 | Nov 2006 | US |