Note: Descriptions are shown in the official language in which they were submitted.
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INSULATION DISPLACEMENT CONNECTOR
This invention relates to insulation displacement
connectors.
Insulation displacement connectors are known in
5 which two conductor wires are connected together in an
insulating housing structure by the use of conductors
having insulation displacing terminals at one or each end.
In such structures, there may normally be a housing and a
cap is screwed down into the housing to connect one or both
of the insulation displacement terminals to an individual
conductor wire so as to connect, for instance, a customer's
service to a central office. The cap is normally provided
with a pair of wires aligned with one of the invention
displacement terminals and the other insulation
displacement terminal is aligned with another pair of
wires. Examples of known structures of this type are
described in U.S. Patent 4,652,071 granted March 24, 1987
in the name of G. Debortoli, et al and U.S. Patent
4,741,480 in the name of P. Despault, et al granted May 3,
1988.
In use of this type of structure, overvoltage and
overcurrent protection is also provided by surge devices
which are placed electrically in series with the insulation
displacement connector. Problems are inherent with such an
arrangement in that the overvoltage and overcurrent
protection devices are connected to conductor wiring by
binding posts which are extremely difficult to protect from
the environment and corrosion of the binding post
terminations may result. This may lead to breakages in
electrical connection through the overvoltage and
overcurrent protection devices is a well known phenomenon.
The present invention seeks to minimi ze or avoid
the above problem.
According to the invention, an insulation
displacement connector for at least one circuit line
comprises first housing means sealingly enclosing an
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electrical surge protection means which is connected at one
side to ground means and at the other side to first
conductor means of the circuit line, the first conductor
means having two terminals extending externally of the
first housing means, a second housing means movable into a
closed condition with the first housing means, second and
third conductor means located within the second housing
means and each having at one end an insulation displacement
terminal for connection to an insulated conductor wire and
having at the other end another terminal which connects to
an individual of the terminals of the first conductor means
with the two housing means closed together, the second
housing means comprising means for aligning a conductor
wire with each of the insulation displacement terminals and
for connecting the conductor wires to the insulation
displacement terminals.
nith the above structure according to the
invention the electrical surge protection means is provided
in the connector instead of being connected serially with
it. In the structure, electrical connection is in series
through the second conductor means through the first
conductor means and then through the third conductor means
with the electrical surge protection means connected to
ground and connected to the first protection means. The
construction is such that the mating terminals of the two
housing means are brought together during closing together
of the housing means such that connections like binding
posts which are normally provided for connection of the
wiring to protection means is avoided. One of the
terminals of one of the housing means is conveniently a
blade terminal while the other terminal of the housing
means is conveniently a resilient fork for resiliently
receiving an individual blade terminal as the housing means
move into the closed condition. In addition to this, the
sealing of the protection means within the first housing
means ensures that no corrosion within the first housing
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means can take place thereby avoiding electrical shorts
leading therefrom. Further to this, with this construction
according to the invention, in practice a gel or a grease
is conveniently used between the two housing means so that
a seal is provided between them as they are moved into the
closed condition thereby protecting the connection of the
terminals extending between the housing means from ambient
atmospheric conditions.
In a preferred arrangement the connector is
constructed to accommodate two circuit lines, e.g. a "tip"
and "ring" line. Each line has its own second and third
conductor means so that four insulation displacement
terminals are provided. Also four other terminals are
provided for connection to two first conductor means each
having two terminals extending externally of the first
housing means. The two first conductor means are
electrically isolated from one another and each first
conductor means has its own electrical surge protection
device. In a practical arrangement, each of the first
housing means is provided with two chambers each housing an
individual protection device with the terminals of each of
the first conductor means sealingly extending through one
wall of the first housing means with the ground means
located on an opposite wall of the first housing means.
One of the preferred intentions of the invention
is that each of the second housing means is locatable in a
detent position upon the first housing means preparatory
for the second housing means to be moved into the closed
position upon installation. In the detent position, it is
30 preferable for the second housing means to be completely
detachable from the first housing means so that it may be
reversed in position. This enables inlets to passages for
incoming conductor wires to be disposed in one of two
preferred positions dependent upon the site conditions in
35 which the connector is to be used. Also, with the second
housing means in the detent position, the connector is in
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readiness for insertion of connector wires into the second
housing means so that the closed condition may then be
attained at which time electrical connection takes place
through the connector. It is also to be preferred that the
two housing means when in the closed condition cannot be
separated from one another so that the protection means and
the terminal connections to the protection are permanently
protected.
One embodiment of the invention will now be
IO described, by way of example, with reference to the
accompanying drawings, in which:-
Figure 1 is an exploded isometric view of an
insulation displacement connector according to the
embodiment;
Figure 2 is an isometric view of the connector
with one housing means in a detent position upon another
housing means;
Figure 3 is a view similar to Figure 2 showing the
two housing means in completely closed conditions;
Figure 4 is a cross-sectional view and to larger
scale of one of the housing means taken along line IV-IV in
Figure 1;
Figure 5 is a part diagrammatic isometric view
showing four conductors of one of the housing means and
illustrating the electrical connection through the
connector with the two housing means in closed condition;
Figure 6 is a plan view of one of the housing
means and in the direction of arrow VI in Figure 1 to show
the positions of conductor means within that housing means;
and
Figure 7 is a view similar to Figure 4 of a
modification to the embodiment.
In the embodiment, as shown by Figures 1, 2 and 3,
an insulation displacement connector 10 comprises a first
housing means in the form of a lower housing 12 and a
second housing means 14. The first housing means is in the
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form of a molded insulating box which has two spaced
chambers 16 (Figure 4) each chamber individually housing an
electrical surge protection means in the form of a separate
overvoltage and overcurrent protection device 18 which is
5 of solid state construction. One chamber 16 only is shown
in the drawings. As shown by Figure 4, a lower electrode
20 of the device is connected by conductors 22 to a ground
means through a conductive spring 26 and a conductive cup
28 which is slidably received within a cylindrical
formation 30 of the chamber 16. The ground means comprises
a flat plate 24 with flanged edges as shown in Figure 4 and
this flat plate extends beneath the housing 12 to close a
lower opening of each chamber 16, a seal being provided in
the form of a gasket 32 received in a groove of the housing
12 to seal the ground plate in position and protect the
chamber 16 and its contents from ambient atmospheric
conditions. As shown in Figures 1, 2, 3 and 4, the ground
means also includes a flange 34 extending from the plate 24
upwardly around one side of the housing 12 the flange
extending horizontally outwards as a slotted end 36 for
connection to a suitable ground pin.
The upper electrode 38 of each device 18 is
individually connected to its own conductor means 40 molded
within the housing. Each of the conductor means 40 as
shown by Figure 6 comprises a pressed conductive metal
plate 42, two plates being formed so as to interfit with
each other while being spaced apart as shown by Figure 6
and also with each plate providing two upwardly extending
blade terminals 44, the disposition being such that the
blade terminals 44 are retained in straight-line equally
spaced-apart positions by the housing. The relative
positions of the terminals are shown particularly in
Figures 1 and 6 and as may be seen, each of the terminals
projects upwardly from an upper wall 46 of the housing 12.
Upon failure of the device 18, the conductive cup 28 is
pushed upwards by the spring 26 so that the rim of the cup
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provides a permanent ground against the underside of the
associated plate 42.
The upper housing means 14 comprises a molded
insulating box 16 formed with two spaced vertically
extending cavities 19, each open at its top. Within each
of the cavities 19 two conductors are retained in position
within the box as illustrated by conductors 48 for instance
in Figure 1. Each conductor 48 as shown by Figure 5 is
upwardly elongate and has an upper end with inwardly
o inclined edges 50 for the purpose of guiding an insulated
conductor wire into an insulation displacement terminal
formed between opposed edges 52 of an upwardly extending
fork 54 of the conductor 48. At its lower end, each
conductor 48 is provided with a fork terminal 56 for
connection with an individual one of the terminals 44 when
the housings 12 and 14 are assembled together in a closed
condition as will be described. In general therefore each
of the conductors 48 is located in the box 16 in a manner
similar to that described in U.S. Patent 4,652,071, a main
difference being that the terminals 56 project outwardly
below the box 16 for connection to the terminals 44 as
distinct from the location of lower terminals in Patent
4,652,071 which were contained within the housing itself.
The upper housing means also is provided with
means for aligning a conductor wire with each of the
insulation displacement terminals 52 and for connecting the
conductor wires to each of these term~ n~ 1s. This aligning
and connecting means comprises two caps 60 (Figures 1, 2
and 3), each cap for vertical movement into and out of an
individual vertical cavity 19. Each of the caps is
provided with two large diameter inlets 62 for large
diameter wires and small diameter inlets 64 which are
inclined downwardly for small diameter wires, the
construction of each of the caps 60 with its passages 62
and 64 being as described in U.S. Patent 4,741,480. As
described in that patent the smaller diameter passages 64
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are provided for ensuring positive connection of small
diameter wires with each of the insulation displacement
terminals 52 without the wires becoming bent during the
assembly process. Also as described in the above-mentioned
5 previous patents, a screw-threaded means is provided for
screwing each of the caps 60 into and out of an operating
position within its cavity 19. This screw-threaded means
comprises a screw 66 extending through its individual cap,
the screw received within a screw-threaded hole (not shown)
o towards the bottom of the box 16.
It is intended that the box 16 should be assembled
to the housing 12 in two alternative different positions.
For this purpose the housing 12 has two molded upward
extensions 70 on each side of the housing, each of the
15 extensions 70 being resiliently flexible in an outward
direction and being receivable within a corresponding
shallow recess 72 in a side of the box 16. As will be
seen, each of the extensions 70 is formed with two
horizontal slots 74 and 76 (although the lower slot 76 in
each case need only be a recess in the inside wall of each
extension 70). Within each of the shallow recesses 72 two
horizontal projections 78 and 80 are provided. As shown by
Figure 2, in the detent position of the box 16 upon the
housing 12 each of the lower projections or ribs 80 is
received in an individual upper slot 74 so that the box 16
has a lower surface spaced away from the housing 12. In
the detent position, the terminals 44 are spaced from and
therefore disconnected from the lower fork terminals 56 of
the conductors 48. Also, with the box 16 in the detent
position it is possible for the extensions 70 to be
flexibly moved apart by an upward pull on the box 16 to
enable the box to be turned around 180 horizontally upon
the housing 12 so as to position the inlets 62 and 64 to
face in the opposite direction from the housing 12 from
that shown in the Figures. This is particularly useful
under certain conditions where it is difficult to connect
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the slotted end 36 of the ground plate to a ground pin and
also have the connector wires extending into the connector
from the same side.
Figure 3 shows the lower or closed condition of
the box 16 upon the housing 12. In this condition, each of
the ribs 78 is received in a slot 74 and each rib 80 is
received within a slot 76 or in its alternative recess as
discussed above. This movement into the closed position is
irreversible as one or both of the ribs 74 and 76 lock
o against complementary surfaces of the respective slots so
that the assembly is permanently maintained.
As will be seen however, the extensions 70 are
exposed in the closed position of Figure 3. The extensions
70 while being resiliently flexible are also frangilble.
In the event that either of the protection devices 18 fails
and permanently connects a circuit line to ground,
sufficient of the extensions 70 may be broken away to allow
for removal of the box 16 from the housing 12. The box 16
thus remains undamaged and a replacement housing 12 with
its components in working order may be connected to box 16.
With this replacement method, the wires 80 or 82 remain
connected into the insulation displacement terminals 52.
In use of the connector, initially the parts are
as shown in Figure 1 and to completely seal each of the
chambers 16 from ambient atmosphere, a suitable sealing
grease or gel is positioned around lower ends of the
terminals 44 projecting through the upper wall 46 so as to
seal any space at that position. The connector is
conveniently sold with the box 16 in the detent position
30 upon the housing 12 as shown in Figure 2. An installer may
then position the box 16 in either of the two positions
convenient to him and as discussed above. To make
electrical contact through the connector, it is necessary
for each of the caps 60 to be in an upper position (left-
hand side of Figure 2 as distinct from its operationalposition - right-hand side of Figure 2). In the upper
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position of each of the caps 60, large diameter conductor
wires 80 or alternatively small diameter conductor wires 82
as illustrated in Figure 2 are passed as desired through
the appropriate inlets 62 or 64 in each of the caps 60, the
passages having previously been filled with a sealing
substance such as a suitable grease or gel for sealing
purposes. Each of the caps is then screwed downwards into
the box 16 and into its operating position as shown on the
right-hand side of Figure 2. For accommodating the wires
o 80, downward slots 84 are provided in the box 16 to align
with the inlets 62 as shown. As each of the caps 60 moves
into its operational position the wires 80 or 82 are
aligned with the insulation displacement terminals 52 and
as downward movement continues by the cap, the wires are
contacted by the insulation displacement terminals 52, the
wires moving into the terminals which cut into the
insulation and make electrical contact with the conductors
inside. Upon this connection having been made, the housing
16 may then be pushed downwardly from the detent position
into the fully closed position upon the housing 12 in which
it is permanently fixed so as to fully protect the
interconnection which is then made between the blade
terminals 44 and the fork terminals 56 of the conductors
48. During this movement into the fully closed position,
any grease or gel surrounding the blade terminals 44 is
pressed outwardly across the upper surface of the upper
wall 46 so as to form an effective seal between the two
housing means.
In an alternative method of assembly, the box 16
is pushed downwards into its fully closed position on the
housing 12 before the caps 60 are moved downwards with the
conductor wires for connection to the insulation
displacement terminals 52.
To prevent overstressing the housing 14 and the
caps 60, means is provided for providing an audible signal
which indicates when each cap 60 is in its completely
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assembled position within its respective cavity 19. With
regard to each of the cavities 19, the means for making the
audible signal comprises a resiliently flexible flap 86
which extends upwardly between the slots 84 and has a
vertical slot 85. The cap 60 is provided with a lower
projection 88 for receiving in the slot 86, the projection
88 moving vertically in its respective slot 85 during
movement of the cap into and out of its assembled position
for the purpose of retaining the cap in the housing 14 when
lo the cap is in its fully raised position. In addition, the
cap 60 is provided with a further projection 90 vertically
above the projection 88. With the cap in its upper
position as shown by Figure 2, the projection 90 is
disposed above its corresponding flap 86. As the cap 60 is
moved downwardly to its lower position (right-hand side of
Figure 2) the projection 90 moves downwardly and an
inclined front surface of the projection 90 acts against
the flap 86 so as to resiliently urge the flap outwards to
enable the projection to slide past the top of the flap to
be eventually received within a slot 85. Upon the
projection 90 being received in its slot 85, the upper end
of the projection has a horizontal surface as shown and
this enables the flap to return resiliently and suddenly so
that the free end of the flap hits against the cap 60
thereby causing an audible sound which occurs when the cap
60 is in its most downward and operative position.
The connector conveniently provides a single unit
in which wire connections are housed in the connector and
in which the overvoltage and overcurrent devices 18 are
30 provided and are effectively sealed against ambient
atmospheric conditions. It also provides a device in
which, because of the location of the devices 18 in the
unit, and also because of the use of the two caps 60, may
be tested for any possible fault as will now be explained.
35 With the connector wired correctly, the two wires 80 or 82
entering into the one cap 60 should be from the central
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office location while the other two wires 80 or 82 entering
the other cap 60 should be the wiring to the customer's
premises. Thus, with reference to Figure 5 which shows the
electrical connections through the connector in the final
closed condition, the conductors 48a and 48b have their
insulation displacement terminals 52 connected to wires 80
or 82 from the central office whereas the terminals 52 of
the conductors 48c and 48d are connected through conductor
wires to the customer's premises. The conductors 48a and
o 48b are housed in one of the cavities 19 whereas the
conductors 48c and 48d are housed in the other cavity 19.
As may be seen therefore from the diagrammatic
representation of Figure 5, conductor 48a is connected
through its individual blade terminal 44, through the
corresponding conductor plate 42 and then into the
conductor 48c through the other blade terminal 44 of that
particular conductor means 40. In similar fashion the
conductor 48b is connected to the conductor 48d through
their respective blade termin~ls 44 and the plate 42 of the
other conductor means 40. As also shown diagrammatically
by Figure 5, the two devices 18 are connected between their
respective conductor plates 42 and ground. As may be seen
from Figures 1, 2 and 3 particularly, each of the caps 60
is provided with two vertical ports 90 for test purposes,
these ports extending downwardly for location of test
probes into contact with respective conductors 48a to 48d.
Test ports 90 are normally conveniently covered with covers
92 which are manually pressed into position and may be
manually released for test purposes.
Hence, with the cap 60 associated with the central
office conductors 48a and 48b raised to its upper position,
this disconnects the central office wires from the
connector because the blade termin~ls 44 are disconnected
from the four end terminals 56 of the conductors 48a and
35 48b. Test probes may then be inserted into the appropriate
test ports 90 for testing the customer's circuit which is
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still connected to the connector by means of the conductors
48c and 48d. Alternatively, the other cap associated with
conductors 48c and 48d may be raised thereby severing
connection to the customer's wiring. In this condition
probes may be appropriately inserted into the ports 90 for
testing the central office circuit which is still connected
to the connector by the conductors 48a and 48b. As a
further alternative, with both caps 60 raised plugs may be
connected to the blade terminals 44 for the purpose of
0 testing the overvoltage and overcurrent protection to
ground through the devices 18 or for testing through the
conductor plates 42 to ascertain whether a desired circuit
is completed from side-to-side of the housing 12 without
any short occurring through the insulating material of the
housing from one plate to another. As may be seen
therefore not only does the assembly of the connector
provide for complete sealing action for the terminals and
overvoltage and overcurrent device in one unit, but it also
enables a complete electrical circuitry test operation to
be completed.
In a modification to the embodiment described
above in which like parts bear the same reference numerals,
an insulation displacement connector 94 (Figure 7) which is
otherwise similar to the connector 10 described in the
first embodiment, the overvoltage and overcurrent
protection means is provided by two gas tubes 96 of
conventional construction, instead of by the solid state
devices 18 shown. One only of the devices 96 is
illustrated in Figure 7. As with the embodiment, a
conductive cup 28 is provided for connection to each of the
plates 42 upon failure'of the gas tube for permanent
connection of one or both lines to ground.
