Title: Jack for data transmission
Abstract: This invention relates to an improved jack for data transmission, and in particular provides the jack having improved cross-torque characteristics. A jack is provided comprising a body having m unted thereon a multiplicity of metal strips. The strips include a first group of metal strips each of which includes a contact portion (7) for contacting a conductor of a mating plug and a connection portion for connection to a printed circuit board on which the jack, in use, is mounted. The strips also include a second group of metal strips each of which extends parallel to at least one metal strip of the first group over a part of the length of the metal strip of the first group and which is electrically connected to a different metal strip of the first group.
Patent Number: 6,869,317 Issued on 03/22/2005 to Weatherley
| Inventors:
|
Weatherley; Richard (Brackmills, GB)
|
| Assignee:
|
Hellermanntyton Data Limited (Crawley, GB)
|
| Appl. No.:
|
380072 |
| Filed:
|
June 2, 2003 |
| PCT Filed:
|
July 5, 2001
|
| PCT NO:
|
PCT/GB01/03018
|
| 371 Date:
|
June 2, 2003
|
| 102(e) Date:
|
June 2, 2003
|
| PCT PUB.NO.:
|
WO02/23681 |
| PCT PUB. Date:
|
March 21, 2002 |
Foreign Application Priority Data
| Current U.S. Class: |
439/676; 439/941 |
| Intern'l Class: |
H01R 024//00 |
| Field of Search: |
439/676,941,620,344,630
|
References Cited [Referenced By]
U.S. Patent Documents
| 5362257 | Nov., 1994 | Neal et al.
| |
| 5547405 | Aug., 1996 | Pinney et al.
| |
| 5599209 | Feb., 1997 | Belopolsky | 439/676.
|
| 5938479 | Aug., 1999 | Paulsen et al.
| |
| 6007368 | Dec., 1999 | Lorenz et al.
| |
| 6179668 | Jan., 2001 | Kan | 439/676.
|
| 6283795 | Sep., 2001 | Chen | 439/676.
|
| Foreign Patent Documents |
| 0692884 | Jan., 1996 | EP.
| |
| 9963630 | Dec., 1999 | WO.
| |
Primary Examiner: Ta; Tho D.
Assistant Examiner: Figueroa; Felix O.
Attorney, Agent or Firm: Dykema Gossett PLLC
Claims
What is claimed is:
1. A jack comprising a body having mounted thereon a multiplicity of metal
strips, the metal strips including:
a first group of metal strips each of which includes a contact portion for
contacting a conductor of a mating plug and a connection portion for
connection to a printed circuit board on which the jack, in use, is
mounted;
a second group of metal strips each of which extends parallel and adjacent
to at least one metal strip of the first group over a part of a length of
the metal strip of the first group, each of the metal strips of the second
group having a first end forming a connection portion for connection to a
printed circuit board on which the jack is, in use, mounted, and a second
end which is spaced apart from said metal strips of said first group;
an encapsulation encapsulating portions of all the metal strips such that
the contact portions extend from a first side of the encapsulation whereby
the connection portions of the first group of metal strips may be
connected to tracks of the printed circuit board to effect an electrical
connection between each contact portion and a track on the printed circuit
board; and
means electrically connecting each metal strip of the second group and a
metal strip of the first group which is different from the metal strip of
the first group to which the metal strip of the second group lies
adjacent, such that each said metal strip of the second group forms a
conducting spur connected only at one end to said metal strip of the first
group.
2. A jack as claimed in claim 1, wherein the metal strips of the second
group are cropped so that they do not include any portion in a region of
the contact portions of the first group of metal strips.
3. A jack as claimed in claim 1, wherein the strips are formed by two
superimposed layers of a pre-formed common blank, one of the layers of
blank being inverted relative to the other layer.
4. A jack as claimed in claim 1, wherein at least some of the strips
include pad portions which cooperate with pad portions of others of the
strips to enhance impedance matching characteristics of the jack.
5. A jack as claimed in claim 1, wherein the metal strips include a common
region which is a suitable plastics material.
6. A jack as claimed in claim 5, wherein the contact portions of the first
group extend from one end of the encapsulated region and the connection
portions of the first group of strips extend from another end of the
encapsulated region.
7. A jack as claimed in claim 5, wherein the strips of the second group do
not extend beyond the first side of encapsulated region.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an improved jack for data transmission, and in
the preferred embodiment provides a jack having improved cross-talk
characteristics.
2. The Prior Art
Jacks (and their associated plugs) are widely used in data transmission
systems for providing a plug-in connection between components. For
example, jacks are extensively used on patch panels and wall outlets of
structured cabling systems and on electronic equipment to permit
connection of equipment to structured cabling systems using patch leads.
The so called RJ45 plug is extensively used within the cabling industry
and the vast majority of jacks are devised to be compatible with RJ45
plugs.
There are various internationally agreed standards for the performance of
structured cabling systems. The current mainstream standards are the so
called "Category 5" (commonly referred to as Cat 5) and the somewhat
improved "Category 5 enhanced" (generally referred to as Cat 5e). A higher
standard (Category 6 or Cat 6) has recently been proposed. Cat 6
specifications require lower levels of near end cross-talk (NEXT) and far
end cross-talk (FEXT) and improved return loss values than the earlier Cat
5 and Cat 5e standards. In order to meet Cat 6standards it has been
necessary to re-design both plugs and jacks, whilst keeping within the
physical parameters of the RJ45 plug specification.
By careful design of the plug and the circuit board to which the jack is
secured it has been possible to design plug and jack combinations which
meet Cat 6 standards without any fundamental alteration to the standard
jack construction. However, it is now considered desirable that both the
plug and jack of Cat 6 specification equipment must be capable of meeting
Cat 5 specification when used with a mating Cat 5 component. In other
words, it is now desirable that when a Cat 6 plug is inserted into a Cat 5
jack, or a Cat 5 plug is inserted in a Cat 6 jack, the overall combination
should meet Cat 5 standards.
We have now devised an improved jack which assists in meeting the
desideratum of rearward compatibility to Cat 5 standards.
SUMMARY OF THE INVENTION
According to one aspect of the present invention a jack comprises a body
having mounted thereon a multiplicity of metal strips, the metal strips
including: a first group of metal strips each of which includes a contact
portion for contacting a conductor of a mating plug and a connection
portion for connection to a printed circuit board on which the jack, in
use, is mounted; and a second group of metal strips each of which extends
parallel to at least one metal strip of the first group over a part of the
length of the metal strip of the first group and which is electrically
connected to a different metal strip of the first group.
In the preferred embodiment of the invention the strips of the second group
are cropped so that they do not include any portion in the region of the
contact portions of the first group of metal strips.
Preferably, the metal strips include a common region which is encapsulated
in a suitable plastics material. The contact portions of the first group
extend from one end of the encapsulated region and the connection portions
of the first group of strips extend from the other end of the encapsulated
region. Preferably, the strips of the second group do not extend beyond
the encapsulated region in the direction of the contact portions.
In the particularly preferred embodiment of the invention the contact
strips are formed by two superimposed layers of a pre-formed common blank,
one of the layers of blank being inverted relative to the other layer.
In the particularly preferred embodiment of the invention at least some of
the strips include pad portions which co-operate with the pad portions of
others of the strips to enhance impedance matching characteristics of the
jack.
The above and further features and advantages of the invention will become
clear from the following description of a preferred embodiment thereof
given by way of example only, reference being had to the accompanying
drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a portion of blank material used in the
manufacture of jacks in accordance with the preferred embodiment of the
invention;
FIG. 2 is a view of the blank of FIG. 1 inverted relative to the position
shown in FIG. 1;
FIG. 3 is a plan view of the blank of FIG. 2 superimposed on and in
register with the blank of FIG. 1; and
FIG. 4 is a perspective view of the superimposed strips of FIG. 3 showing
the encapsulation of a common region of the strips,
FIG. 5 is a perspective view of the superimposed strips of FIG. 3
encapsulated to form the jack of the invention, and
FIG. 6 is a perspective view of the jack of FIG. 5 mounted on a board and
incorporated into a jacket socket.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring firstly to FIGS. 1 and 2, the blank material 1 used in the
manufacture of jacks according to the present invention comprises side
regions 2, 3 and strips 4 extending between the side regions. The blanks
may be formed by any suitable means, from any suitable material. For
example, they may be formed by stamping from phosphor-bronze. The side
regions 2, 3 include holes 5. The holes 5 serve to receive drive pins in
automated assembly equipment and ensure correct registration of the
superimposed blanks, as described below.
Each groups of strips 4 comprises five strips A,B,C,D, and E. It will be
noted that, as manufactured, each strip is continuous between and is
initially integral with the side regions 2,3. The strips A,C and E include
pads 6 for impedance matching purposes, as described in more detail below.
The strips A,B,C and E will, in the finished jack, provide contact portions
for electrical connection to corresponding contacts of a plug. The region
7 of the strips which will provide the contact portions may be suitably
treated after the blanks have been formed, for example by mechanical
treatment and/or electro-plating.
It will be noted that the strip D will not provide a contact portion in the
finished jack.
In order to form a jack, two layers of the blank material are required, the
second layer being superimposed on the first layer but inverted relative
to the first layer. The blank 1 shown in FIG. 2 has this inverted
relationship relative to the blank of FIG. 1.
To form the jack, the two layers of blank material are superimposed as
shown in FIG. 3, the holes 5 being used to ensure correct registration of
the two layers. In FIG. 3, the various strips of the upper layer are
identified with the prefix "U" and the various strips of the lower layer
are prefixed with the "L". It will be noted that in the superimposed
configuration shown in FIG. 3 the lower B strip LB is not visible since it
lies directly underneath and is covered by the upper D strip UD. Likewise,
the lower D strip LD is not visible in FIG. 3 since it lies under and is
covered by the upper B strip UB.
In order to form a contact sub-assembly for insertion into a jack body a
common central region 8 of the strips 4 is encapsulated in a suitable
plastics encapsulation 9. As a practical matter, the encapsulation can
conveniently be done in two stages by forming an initial encapsulation 9A
which encapsulates the common region 8 of the lower blank and forming a
second encapsulation 9B which encapsulates the common region 8 of the
upper blank. The encapsulations 9A and 9B may be formed separately and
fixed together after moulding. Alternatively, encapsulation 9A may be
formed, the upper blank may be superimposed on that encapsulation, and the
encapsulation 9B may be formed in situ. The resultant arrangement is shown
on the left hand portion of FIG. 4 and the arrangement of the strips prior
to encapsulation is shown on the right hand portion of FIG. 4. It will be
appreciated that, in practice, there will be a number of intermediate
stages between the left and right hand portions of FIG. 4. The totally
unencapsulated and totally encapsulated stages are shown in juxtaposition
for convenience only.
Once the encapsulation has been completed so that the configuration shown
on the left hand portion of FIG. 4 has been achieved the strips 4 complete
with the encapsulation 9 may be cropped from the side regions 2,3, trimmed
to size, and in the case of the contact portions bent with the
conventional reverse bend. Each of the D strips (LD and UD) are cropped
immediately adjacent the side 10 of the encapsulation 9 which faces the
contact portions 7. Accordingly, the contact portions 7 total eight in
number in accordance with conventional RJ45 standards. On the reverse face
11 of the encapsulation facing the connection portions 12 of the strips a
total of ten strips leave the encapsulation. As will be appreciated by
those skilled in the art, eight of these form contact portions which may
be connected to tracks of a printed circuit board on which the jack is
mounted to provide electrical connections to the eight contacts provided
by the contact portion 7. The remaining two strip portions (provided by
the LD and UD strips) are preferably each connected to one of the other
contact portions. The required connection can conveniently be provided by
means of tracks on the printed circuit board to which the jack is
attached. The exact connection arrangements will depend on the connections
required to provide the desired cross-talk characteristics. In certain
instances it may be possible to provide a direct connection between one or
both of the LD and UD strips and an adjacent contact portion, thereby
obviating the need for additional tracks on the PCB.
It will be noted that, in the assembled configuration of the strips, the
pad 6 associated with strip UE overlies and is substantially coterminous
with the pad 6 of the strip LA. Similarly, the pad of the strip UC
overlies and is substantially coterminous with the pad 6 of the strip LC.
Finally, the pad 6 of the strip UA overlies and is substantially
coterminous with the pad 6 of the strip LE. The pairs of mating pads 6 do
not materially affect the cross-talk of the jack but are useful in
assisting impedance matching of the jack.
It will be appreciated that whilst in the preferred embodiment of the
invention the contact portions of strips LD and UD are electrically
connected to their respective overlying and underlying strips UB and LB
other arrangements may be desirable depending on the exact nature of the
cross-talk reduction which is required.
Whilst in the preferred embodiment of the invention two extra strips LD and
UD are provided, it will be appreciated that the invention is not limited
to the use of two additional strips but on the contrary encompasses any
number of additional strips depending on the nature of the cross-talk
compensation required.
*
