Note: Descriptions are shown in the official language in which they were submitted.
3~
ISDN QUI~K CONNECT TERMINATING RESISTOR
This invention relates to cross-connect conn~ctors
and more particularly to a terminating resistor for use
therewith.
In a telecommunication system, an incoming cable
to a customer's premises is connected to a distribution cable
for distribution of the electrical wiring to access points
and terminals within the premises. The distribution cable
may itself be connected to a further cable or to series or
parallel cables, to assist in the wiring distribution. At
each connection location between cables, it is now common
practice to use a distribution frame which detachably carries
connectors for electrically connecting the conductor wires of
one cable with those of another or others. These connectors
are normally of a construction referred to as "cross-connect
connectors" in that each connector comprises a dielectric
body with two spaced rows of electrical terminals held by the
body. The terminals of one row are interconnected
electrically and in desired fashion with those of the other
row through the dielectric body.
According to normal practice, at each distrihution
frame, an incoming cable is brought into an input location of
the frame and its conductor wires are distributed as required
to the various positions for mounting to a first and second
set of cross-connect connectors and through to end use
equipment, such as telephones and data processing terminals.
For ISDN deployment within a building, a resistor box is used
between the first and second set of cross-connect connectors
in order to maintain a balanced loop. In particular, a
conductor wire is led from each unused terminal of each
cross connect connector to the resistor box. Since the whole
connection procedure is manual, it is an arduous and lengthy
process particularly as there may be as many as twenty-five
terminals along each row of a connector and some distribution
frames have ten or more connectors.
The present invention basically provides a quick
connect terminating resistor for use across terminals of
cross-connect connectors and which eliminates the need for a
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resistor bo~ and its associated wiring. The invention not
only simplifies the initial installation but makes the
modification to install additional telephones and lines much
easier and less time consuming.
Accordingly, the present invention provides a
quick connect terminating resistor for use with cross-connect
type of connectors, comprising: a body having a connecting
end; conductor portions on said body at said connecting end
adapted to mate with a pair of terminals of said cross
connect type connector; and resistor means connected to said
conductor portions for providing a terminating resistance
across said pair of terminals of said cross-connect type
connector.
~rief Description of the Drawings
Particular embodiments of the invention will be
understood in conjunction with the accompanying draw.ings, in
which:
Figure 1 is an illustration of a prior art
connecting arrangement used in a typical distribution frame;
Figure 2 is an isometric view of a distribution
frame and cross-connect connector assembly according to the
prior art;
Figures 3a and 3b are side and front views
respectively of a typical cross-connect connector;
Fiyures 4a and 4b are side and bottom views
respectively of the quick connect terminating resistor
according to a first embodiment of the invention;
Fi~ures 5a and 5b are a partially-sectioned side
view and a bottom view, respectively, of a quick connect
terminating resistor according to a second embodiment of the
invention;
Figures 6a and 6b ara a partially-sectioned side
view and a bottom view respectively of a quick connect
terminating resistor according to a third embodiment of the
invention;
Figures 7a and 7b are a partially-sectioned side
view and a ~ottom view respectively of a quick connect
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terminating resistor according to a fourth embodiment of the
invention; and
Figure 8 is an illustrative view showing the
positioning of the terminating resistor with respect to the
cross-connect connector.
Description of the Preferred Embodiment
As shown in Figure 1, typical distribution frames
10 and 11 are used to assist in the wiring distrihution to
access points and terminals 12 and 13 within the premises.
Depending on the size of the building, the distribution
frames are either located in the basement or on each floor of
an office building in what is commercially referred to as a
floor closet 14.
In a typical communication system, an incoming
cable from the central office (CO) 15 enters the premises
through a protector 16 in equipment room 17. The incoming
cable is then distributed to various offices by means of a
main distribution frame 18 and via a network termination 19.
The network termination outgoing cable 20 is then directed to
the floor closet 14. The outgoing cable 20 is then brought
inko an input location of the frame 10 and its conductor
wires are distributed as required to the various positions
for mounting to the cross-connect connectors. In Figure 1,
only one distribution cable 21 is shown for simplicity. A
resistor box 22 is used for each network termination 19.
Accordingly, if only a few distribution cables are used at
the distribution frame 10 or if only a few access points or
terminals are used at frame 11, then a number of wires
equivalent to the number of unused distribution wires will be
required between the distribution frame and the resistor box
22. This not only increases the complexity of the task but
also the associated installation time.
Figure 2 is an isometric view of a typical
distribution frame and wiring ass~mbly which can be used with
the present invention. It is comprised of a distribution
frame 30 having a plurality of mounting shelves 31 for
detachably holding a plurality of cross-connect connectors 32
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in predetermined locations. In the embodiment of figure 2,
the distribution frame 30 has five mounting shelves, each
comprised of a pair of axially aligned and spaced rows of
cross-connect connectors 33. In a finished assembly, an
incoming cable 34 has its insulated conductor wires 35
separated into groups and these groups are passed to the
cross-connect connectors 32, one group to each connector. A
portion of outgoing wires 36 are distributed to access points
or terminals that are in use (i.e. 12 and 13) and the
remaining wires are distributed to resistor box 20 to
maintain a balanced loop for those terminals that are not in
use.
Figures 3a and 3b show a cross-connect connector
40. It is comprised of a substantially planar body 41 made
of dielectric material having along each edge a row of
terminals 42a and 42b. In this known connector structure,
each of the terminals comprises two opposed electrically
conductive portions 43a and 43b arranged on either side of a
molded groove 44 in an edge of the body 41. These conductor
portions act to cut into the insulating material surrounding
a conductor wire when the wire is forced into the groove so
that the conductor portions electrically contact the
conduator wire. Such terminals are normally referred to as
insulation displacement terminals. This cross-connect
connector structure is used for the distribution of
electrical wiring to access points and terminals within a
customer's premises. In this structure, terminals of one row
e.g. terminals 42a, are connected to conductor wires of one
cable or group of cables and terminals of the other row of
terminals, e.g. terminals ~2b, are connected to another cable
or group.
In this prior art arrangement, a lengthy assembly
procedure of outgoing wires 36 is necessary between the
distribution frame and a resistor box. Also, because the
location of the distribution frame itself may not be easily
accessible, the assembly of the wires into the cross-connect
connectors may be a difficult operation for the assembler.
With the present invention however, the above
disadvantages are avoided or minimized.
In a first embodiment as shown in Figures 4a and
4b, a quick connect terminating resistor 50 replaces the need
for a resistor box and its associated wiring. It is
comprised of a generally planar body 51 having a connecting
end 52. A pair of conductor portions or blades 53 and 54 are
provided at the connecting end 52 and are adapted to mate
with a pair of terminals on one edge of the cross-connect
connectors. A resistive element 55 is connected between
conductor portions 53 and 54 to provide a terminating
resistance across the pair of terminals on the cross~connect
connector. Resistive element 55 can consist of a planar
ceramic resistor and should preferably include a fuse or
other protection circuitr~ for inside and outside plant
protection. For example, a capacitor can be incorporated
with the planar resistor as part of the protection circuitry.
Conductor portions 53 and 54 are connected to resistive
element 55 by means of leads 56 and 57 respectively.
Retaining means 58 can be provided to latch the terminating
resistor 50 to the cross-connect connector. The retaining
means 53 can consist of a resilient finger having a
protruding inclined edge 59 which latches against an abutment
shown in Figures 3a and 3b as reference numeral 45.
The embodiment of Figures 5a and 5b is similar to
the embodiment of Figures 4a and 4b. However, in the
embodiment of Figures 5a and 5b, the terminating resistor 60
is provided with a cavity 61 at one end thereof to receive a
resistive element 62. With this arrangement, the body 63
should be made of heat dissipating material if resistive
element 62 is to generate heat. The resistiva element 62 is
similarly connected between the two conductor portions 64 and
65 by means of leads 66 and 67 respectively.
Figures 6a and 6b represent another embodiment of
the present invention. The terminating resistor 70 has a
similar generally planar body 71. However, the connecting
portion 72 is positioned centrally thereof. In this
embodiment, separate cavities 73 and 74 are located at each
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end of the terminating resistor. Resistive elements 75 and
76 are positioned therein. A connecting lead 77 connects
conductor portion 78a to resistive element 75 which is
connected in series with resistive Qlement 76 by means of
lead 79. Resistive element 76 is connected to the opposite
conductor portion 78b.
Figures 7a and 7b represent yet another embodiment
of the present invention. ~he terminating resistor 80 also
has a generally planar body 81 and a centrally positioned
connecting portion 82. However, the resistive element 83 is
enclosed in a single cavity 84~ A connecting lea~ 85
connects conductor portion 86 to resistive element 83 and
connecting lead 87 connects the other end of resistive
element 83 to the opposite conductor portion or blade 38.
In operation, when an unused terminal of a cross-
connect connector is required to be connected to a
terminating load, a quick connect terminating resistor such
as shown in Figure 7 at reference numeral 90 is inserted over
the particular terminal pair of cross-connect connector 91.
The terminating resistor is pressed onto the connector until
the retaining latch 92 comes in abutment with groove 93 on a
side edge 94 o e connector 91. ~ecause of their generally
planar ~hape, a number of terminating resistors can be placed
and oriented one adjacent another.
As shown from the above embodiments, it is a
simple matter to provide a terminating impedance across one
or any pair of connectors thereby simplifying the wiring in a
distribution frame itself.
