Information
-
Patent Grant
-
6568953
-
Patent Number
6,568,953
-
Date Filed
Thursday, January 31, 200223 years ago
-
Date Issued
Tuesday, May 27, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Bradley; P. Austin
- Gushi; Ross
Agents
- Bicks; Mark S.
- Goodman; Alfred N.
- Hoffman; Tara L.
-
CPC
-
US Classifications
Field of Search
US
- 439 418
- 439 417
- 439 344
- 439 676
- 439 941
-
International Classifications
-
Abstract
An electrical connector includes a dielectric body having an input end and an output end opposite the input end. First and second electrical contacts are located at the output end. A twisted wire pair is connected to the first and second electrical contacts, defines an axial length, includes first and second wires twisted along the axial length, and has first and second terminal ends. The first and second terminal ends are connected to the first and second electrical contacts and include first and second portions. The first portion is located axially between the second portion and first and second terminal ends of the first and second wires. The first portion has a first degree of twist about a longitudinal axis of the twisted wire pair. The second portion has a second degree of twist about the longitudinal axis of the twisted wire pair. The first degree of twist is substantially greater than the second degree of twist.
Description
FIELD OF THE INVENTION
The present invention relates to an electrical connector that meets high performance standards particularly in high speed data transmissions. More specifically, the present invention relates to an electrical connector, such as a telecommunications plug, receivable in a another mating connector, such as a telecommunications jack, that includes overtwisted wire pairs in the connector to reduce crosstalk, thereby increasing performance to meet high performance standards, such as in category 6 applications.
BACKGROUND OF THE INVENTION
Advancements in telecommunications require high speed data transmission. In order to meet performance standards for high speed data transmission, such as category 6 performance standards, crosstalk must be reduced. Conventional electrical connectors, such as telecommunication plugs and jacks, produce unacceptable levels of crosstalk due to interfering signals from the wires of the connectors, thereby degrading the performance of the connector. In particular, conventional plugs, such as the industry standard RJ45 plug, terminate cables typically having eight wires that are close together and parallel leading to excessive crosstalk.
A conventional solution to this crosstalk problem is to twist each pair of wires. Specifically, when wires of a pair are twisted their equal and opposite signals cancel each other resulting in a reduction of crosstalk between the wires. However, this solution is often inadequate for high speed data transmissions, particularly due the need to untwist or separate the wires in order to connect them to pins corresponding to their terminal assignments. Specifically, the distance from where the wires are separated to the pins significantly contributes to crosstalk. Additionally, air or space between individual wires of a wire pair also affects impedance which can increases return loss or signal reflection as the signals travel through the connector, thereby decreasing performance.
Another solution to the problem of crosstalk, is to provide a dielectric insert or block where the wires are separated in the connector, thereby fixing the positions of each wire pair and reducing crosstalk by isolating the signals of the wires from each other. Although this solution reduces crosstalk, incorporation of such inserts is cost prohibitive.
Examples of conventional telecommunications electrical connectors include U.S. Pat. No. 6,007,368 to Lorenz et al; U.S. Pat. No. 5,350,324 to Guilbert; U.S. Pat. No. 5,911,594 to Baker, III et al.; U.S. Pat. No. 6,176,732 to Schultz et al.; and U.S. Pat. No. 5,226,835 to Baker, III, the subject matter of each of which is herein incorporated by reference.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide an electrical connector that reduces crosstalk and improves performance, particularly in category 6 applications.
Another object of the present invention is to provide an electrical connector that is inexpensive to manufacture and also meets performance standards for high speed data transmissions.
Yet another object of the present invention is to provide an electrical connector that includes overtwisted wire pairs to reduce crosstalk and also increase the stability of the wire pairs.
The foregoing objects are basically attained by an electrical connector including a dielectric body that has an input end and an output end opposite the input end. First and second electrical contacts are located at the output end. A twisted wire pair is connected to the first and second electrical contacts. The twisted wire pair defines an axial length includes first and second wires twisted along the axial length, and has first and second terminal ends, respectively. The first and second terminal ends are connected to the first and second electrical contacts, respectively, and include first and second portions. The first portion is located axially between the second portion and first and second terminal ends of the first and second wires. The first portion having a first degree of twist about a longitudinal axis of the twisted wire pair. The second portion has a second degree of twist about the longitudinal axis of the twisted wire pair. The first degree of twist is substantially greater than the second degree of twist.
The foregoing objects are also attained by a method of terminating wires to an electrical connector, comprising the step of twisting together first and second wires to a form a first twisted wire pair having an axial length and first and second portions,. The first portion is located axially between the second portion and the terminal ends of the first and second wires. The method also includes the step of overtwisting the first portion of the first twisted wire pair about the axial length so that the degree of twist about the axial length at the first portion is substantially greater that the degree of twist about the axial length at the second portion. Also, the method includes the step of connecting the first and second terminal ends of the first and second wires, respectively, to first and second electrical contacts, respectively, of the electrical connector.
By forming the electrical connector in the above manner, crosstalk is reduce and performance is enhanced to meet the requirements of high speed data transmissions without the use of an insert.
Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with annexed drawings, discloses a preferred embodiment of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to the drawings which form a part of this disclosure:
FIG. 1
is a partial perspective view of an electrical connector in accordance with an embodiment of the present invention, showing a wire connected to an electrical contact of the connector; and
FIG. 2
is a diagrammatic top plan view of the electrical connector illustrated in
FIG. 1
, showing the overtwisted wire pairs connected to their respective terminal assignments.
DETAILED DESCRIPTION OF THE INVENTION
Referring to
FIGS. 1 and 2
, an electrical connector
10
in accordance with an embodiment of the present invention generally includes a dielectric body
12
that receives a cable
14
having first, second, third, and fourth twisted wires pairs
16
,
18
,
20
and
22
. First, second, third, and fourth twisted wires pairs
16
,
18
,
20
and
22
are overtwisted to reduce crosstalk and improve performance required for high speed telecommunications data transmission, such as for category 6 applications. Electrical connector
10
is preferably a telecommunications plug that is connectable to a mating connector (not shown), such as a category 6 jack.
As seen in
FIG. 1
, the structure of electrical connector
10
is that of a conventional RJ45 plug connector including dielectric body
12
with an input end
24
for receiving cable
14
and an output end
26
receivable in a mating connector for electrical connection therewith. Dielectric body
12
includes an inner cavity
28
for receiving and supporting cable
14
with an access opening
30
provided in input end
24
. The top wall
32
of connector
10
includes an opening
33
near input end
24
shaped to receive a strain relief member (not shown) for crimping cable
14
when received in body inner cavity
28
in a conventional manner. The bottom wall
34
of connector
10
includes a conventional spring lock tab
36
for securing connector
10
to a mating connector.
At output end
26
of connector body
12
are an array of terminal slots
38
extending from a first side wall
40
to an opposite second side wall
42
. Each slot
38
is open at its upper end
44
and receives an electrical contact
46
. As seen in
FIGS. 1 and 2
, electrical contacts
46
represent terminal positions
1
-
8
, respectively, standard in telecommunications connectors. Each electrical contact
46
is preferably a conventional metallic pin having a contact end
48
and insulation displacement end
50
opposite contact end
48
, as seen in FIG.
1
. Each contact end
48
is exposed at the upper ends
44
of terminal slots
38
for electrical connection with the contacts (not shown) of the mating connector. Each insulation displacement end
50
tears or pierces first, second, third, and fourth wire pairs
16
,
18
,
20
and
22
, respectively, for mechanically and electrical connection thereto, as is well known in the art.
As seen in
FIGS. 1 and 2
, cable
14
includes a cable body
52
supporting first, second, third, and fourth wire pairs
16
,
18
,
20
and
22
within a cable jacket
54
with the wire pairs extending through and beyond the cable open end
56
. Cable
14
extends through access opening
30
of electrical connector
10
and into connector inner cavity
28
with the cable body
52
being crimped at connector input end
24
, as is well known in the art.
Cable
14
supports first, second, third, and fourth wire pairs
16
,
18
,
20
and
22
. Each wire pair
16
,
18
,
20
and
22
includes two wires twisted around each other along a longitudinal axis. Wire pairs
16
,
18
,
20
and
22
are shown spaced from one another for illustrative purposes, however, in use these wire pairs are adjacent or overlap one another. In particular, first twisted wire pair
16
includes twisted first and second wires
60
and
62
, second wire pair
18
includes twisted third and fourth wires
64
and
66
, third wire pair includes twisted fifth and sixth wires
68
and
70
, and fourth wire pair includes twisted seventh and eight wires
72
and
74
. As seen in
FIG. 2
, first and second wires
60
and
62
are connectable to electrical contacts
46
at terminal positions
1
and
2
, respectively, by wire terminal ends
76
and
78
; third and fourth wires
64
and
66
are connectable to electrical contacts
46
at terminal positions
4
and
5
, respectively, by wire terminal ends
80
and
82
; fifth and sixth wires
68
and
70
are connectable to electrical contacts
46
at terminals positions
3
and
6
, respectively, by wire terminal ends
84
and
86
; and seventh and eighth wires
72
and
74
are connectable to electrical contacts
46
at terminal positions
7
and
8
, respectively, by wire terminal ends
88
and
90
.
Each wire pair
16
,
18
,
20
and
22
defines a longitudinal axis
92
,
94
,
96
and
98
, respectively, and an axial length
100
,
102
,
104
, and
106
, respectively. Wires
60
and
62
of first wire pair
16
are twisted about longitudinal axis
92
and along axial length
100
. Similarly, wires
64
and
66
of second wire pair
18
are twisted about longitudinal axis
94
and along axial length
102
. Likewise, wires
68
and
70
of third wire pair
20
are twisted about longitudinal axis
96
and along axial length
104
. Also, wires
72
and
74
of fourth wire pair
22
are twisted about longitudinal axis
98
and along axial length
106
.
Each wire pair
16
,
18
,
20
and
22
also defines first portions
108
,
110
,
112
and
114
, respectively, near cable open end
56
and second portions
116
,
118
,
120
and
122
, respectively, at cable body
52
, as seen in FIG.
2
. Each first portion
108
,
110
,
112
and
114
is located axially between respective wire terminal ends
76
,
78
,
80
,
82
,
84
,
86
,
88
and
90
and each respective second portion
116
,
118
,
120
and
122
. Each first portion
108
,
110
,
112
and
114
is overtwisted along the entire length of each first portion, as seen in
FIG. 2
, to reduce crosstalk and increase performance of connector
10
and mechanically strengthen wire pairs
16
,
18
,
20
and
22
. In particular, first portions
108
,
110
,
112
and
114
are overtwisted with a first degree of twist about respective longitudinal axes
92
,
94
,
96
and
98
of wire pairs
16
,
18
,
20
and
22
. The first degree of twist of wire pair first portions
108
,
110
,
112
and
114
is preferably about 360 degrees to 980 degrees about respective longitudinal axes
92
,
94
,
96
and
98
for the length of each respective first portion
108
,
110
,
112
and
114
. The optimum first degree of twist is about 720 degrees along the respective lengths of each of the first portions which is within 8.0 to 10 mm of the terminal ends. The first degree of twist of first portions
108
,
110
,
112
and
114
is preferably substantially greater than a second degree of twist at second portions
116
,
118
,
120
and
122
. The second degree of twist is about 360 degrees about respective longitudinal axes
92
,
94
,
96
and
98
of wire pairs
16
,
18
,
20
and
22
. Preferably, the first degree of twist is about twice the second degree of twist.
The degree of twist is the number of rotations or degrees of rotation the wire makes about the longitudinal axis per unit length along the longitudinal axis.
Assembly of electrical connector
10
includes preparing cable
14
for insertion into connector body
12
by initially overtwisting first portions
108
,
110
,
112
and
114
of respective wire pairs
16
,
18
,
20
, and
22
. The cable jacket
54
surrounds first portions
108
,
110
,
112
and
114
with wire terminal ends
76
,
78
,
80
,
82
,
84
,
86
,
88
and
90
extending though and beyond cable open end
56
. Overtwisting the wire pairs
16
,
18
,
20
, and
22
helps to maintain the wire pairs
16
,
18
,
20
, and
22
in a twisted state.
Cable
14
can then be inserted through access opening
30
, into connector body inner cavity
28
and crimped in a conventional manner. The overtwisting of wire pairs
16
,
18
,
20
, and
22
provides stability and rigidity to the wire pairs, particularly during crimping thereof by the connector strain relief
Once cable
14
is secured within electrical connector
10
, the wire pairs and their terminal ends are connected to their respective terminal positions or assignments
1
through
8
. In particular, wire pair
16
is attached to terminal positions
1
and
2
, wire pair
18
is attached to terminal positions
4
and
5
, wire pair
20
is attached to terminal positions
3
and
6
, and wire pair
20
is attached to terminal positions
7
and
8
. For example, terminal ends
76
and
78
of wires
60
and
62
, respectively, of wire pair
16
are connected to pins
46
at terminals
1
and
2
, respectively, via insulation displacement ends
50
of pins
46
. The signals of wires
60
and
62
are cancelled due to the twisting of the two wires
60
and
62
. Since the wire pair
16
is overtwisted at first portion
108
, any spaced between the wires
60
and
62
are eliminated and the wire pair
16
is made more compact. The compactness and elimination of spaces between the individual wires
60
and
62
of wire pairs
16
ensures less return loss or reflective signal thus increasing performance of the connector, particularly in high speed data transmissions. The remaining wire pairs
18
,
20
and
22
and their respective wires
64
,
66
,
68
,
70
,
72
and
74
are connected to electrical contacts
46
in a similar manner and operate in a similar fashion.
Additionally, the overtwist of wire pairs
16
,
18
,
20
and
22
maintains the twist between the individual wires of each wire pair to within close proximity of electrical contacts
46
, thereby reducing the separation distance of the individual wires. For example, the twist of wires
60
and
62
of wire pair
18
is maintained until separated for connection to electrical contacts
46
at terminal positions
1
and
2
. The distance d, as seen in
FIG. 2
, defined between the point offirst separation of wires
60
and
62
and the point of connection of wires
60
and
62
with electrical connectors
46
is minimized to reduce the separation of wires
60
and
62
. By minimizing the distance d or separation of wires
60
and
62
and maintaining the twist of wires
60
and
62
up to the open end
56
of cable
14
, the signals of wires
60
and
62
cancel each other more effectively, thereby reducing crosstalk. This distance d is also minimized for the remaining wire pairs
18
,
20
and
22
and their respective wires
64
,
66
,
68
,
70
,
72
and
74
in the same manner. Preferably, the overtwist of wire pairs
16
,
18
,
20
and
22
is maintained to within about 8-10 mm of electrical contacts
46
.
Once wire pairs
16
,
18
,
20
and
22
are properly connected to their respective electrical contacts
46
, electrical connector is connectable with a mating connector adapted to receive output end
26
of connector
10
. Spring lock tab
36
secures connector
10
within the mating connector.
While a particular embodiment has been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.
Claims
- 1. An electrical connector, comprising:a dielectric body having an input end and an output end opposite said input end; first and second electrical contacts located at said output end; a twisted wire pair connected to said first and second electrical contacts, said twisted wire pair defining an axial length and including first and second wires twisted along said axial length and having first and second terminal ends, respectively, said first and second terminal ends being connected to said first and second electrical contacts, respectively, and said twisted wire pair including first and second portions with said first portion being located axially between said second portion and said terminal ends of said first and second wires, said first portion having a first degree of twist about a longitudinal axis of said twisted wire pair, and said second portion having a second degree of twist about said longitudinal axis of said twisted wire pair, said first degree of twist being substantially greater than said second degree of twist.
- 2. An electrical connector according to claim 1, whereinsaid first portion of said twisted wire pair is located near said electrical contacts.
- 3. An electrical connector according to claim 1, whereinsaid output end of said dielectric body is connectable to a mating connector.
- 4. An electrical connector according to claim 1, whereinsaid first degree of twist of said first portion is about 360 degrees to 980 degrees.
- 5. An electrical connector according to claim 4, wherein said first degree of twist is about 720 degrees.
- 6. An electrical connector according to claim 1, whereinsaid first and second electrical contacts include insulation displacing ends, respectively, for connection to said first and second wires.
- 7. An electrical connector according to claim 6, whereinsaid dielectric body includes an aperture with an access opening at said input end; and said first twisted wire pair is received in said aperture through said access opening.
- 8. An electrical connector, comprisinga dielectric body having an input end and an output end opposite said input end and a plurality of electrical contacts located at said output end; a cable extending into said input end, said cable including a plurality of twisted wire pairs for connection to said electrical contacts, each of said twisted wire pairs including, an axial length, first and second wires twisted along said axial length, said first and second wires having terminal ends, respectively, each of said terminal ends being connected to one of said electrical contacts, and each of said twisted wire pairs defining first and second portions with said first portion being located axially between said second portion and said electrical contacts, each of said first portions having a first degree of twist about a longitudinal axis of each of said twisted wire pairs, respectively, and each of said second portions having a second degree of twist about each of said longitudinal axes of each said twisted wire pairs, respectively, and said first degree of twist being substantially greater than said second degree of twist.
- 9. An electrical connector according to claim 8, whereinsaid output end being adapted for connection with a mating connector.
- 10. An electrical connector according to claim 8, whereinsaid first degree of twist of each of said first portions of said twisted wire pairs is about 360 degrees to 980 degrees.
- 11. An electrical connector according to claim 10, whereinsaid first degree of twist is about 720 degrees.
- 12. An electrical connector according to claim 8, whereinsaid first portions of each of said twisted wire pairs are located near said electrical contacts.
- 13. An electrical connector according to claim 12, whereinsaid first portions of each of said twisted wire pairs are located less than 10 mm from said electrical contacts.
- 14. A met hod of terminating wires to an electrical connector, comprising the steps of:twisting together first and second wires to a form a first twisted wire pair having a longitudinal axis and first and second portions, with the first portion being axially between the second portion and terminal ends of the first and second wires; overtwisting the first portion of the first twisted wire pair about the longitudinal axis so that the degree of twist about the longitudinal axis at the first portion is substantially greater that the degree of twist about the longitudinal axis at the second portion; and connecting the terminal ends of the first and second wires to first and second electrical contacts, respectively, of the electrical connector.
- 15. A method in accordance with claim 14, further comprising the step ofinserting the first twisted wire pair into a dielectric body of the electrical connector after overtwisting the first portion of the first wire pair.
- 16. A method in accordance with claim 14, further comprising the step ofconnecting an output end of the electrical connector with a mating connector after connecting the first and second wires with the first and second electrical connectors, respectively, the first and second electrical contacts being located at the output end.
- 17. A method in accordance with claim 14, whereinthe overtwisted first portion of the first twisted wire pair is located near the first and second electrical contacts once the first and second wires are connected to the first and second electrical contacts, respectively.
- 18. A method in accordance with claim 17, whereinthe overtwisted first portion is located a distance of less than 10 mm from the first and second electrical contacts.
- 19. A method in accordance with claim 14, further comprising the steps oftwisting together third and fourth wires to a form a second twisted wire pair having a longitudinal axis and first and second portions, with the first portion being axially between the second portion and terminal ends of the third and fourth wires; overtwisting the first portion of the second twisted wire pair about the longitudinal axis so that the degree of twist about the longitudinal axis at the first portion is substantially greater that the degree of twist about the longitudinal axis at the second portion; and connecting the terminal ends of the third and fourth wires, respectively, to third and fourth electrical contacts, respectively, of the electrical connector.
- 20. A method in accordance with claim 19, whereinthe first, second, third, and fourth electrical contacts form an array of electrical contacts located at an output end of the electrical connector.
US Referenced Citations (13)
Foreign Referenced Citations (1)
Number |
Date |
Country |
07169526 |
Jul 1995 |
JP |